Kyushu University Academic Staff Educational and Research Activities Database
List of Reports
Syuntaro Hiradate Last modified date:2021.10.07

Professor / Division of Bioproduction Environmental Sciences / Department of Agro-environmental Sciences / Faculty of Agriculture


Reports
1. K INOUE, S HIRADATE, S TAKAGI, INTERACTION OF MUGINEIC ACID WITH SYNTHETICALLY PRODUCED IRON-OXIDES, SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, Vol.57, No.5, pp.1254-1260, 1993.09, Interactions between mugineic acid (MA) purified from root washings of Fe-deficient barley (Hordeum vulgare L., cv. Minorimugi) and synthetically produced Fe oxides (goethite, hematite, lepidocrocite, and ferrihydrite) were studied in the equilibrium pH range of 3 to 11. The amount of MA adsorbed on Fe oxides was related to their specific surface area and followed the order: ferrihydrite > > goethite greater than or equal to lepidocrocite greater than or equal to hematite. The adsorption of MA on Fe oxides also decreased with increasing equilibrium pH and increased with increasing MA concentration. The MAFe complexes were also adsorbed on Fe oxides, especially on ferrihydrite and goethite, at pH 3 to 7. At pH > 10, however, MAFe complexes were decomposed to MA and Fe(OH)(3) colloids. The amount of Fe dissolved from Fe oxides by MA was in the following order: ferrihydrite > > lepidocrocite greater than or equal to hematite = goethite. The Fe dissolution from Fe oxides by MA was related to their crystallinity and the maximum amount of Fe dissolved by MA was in the pH range of 7 to 8. The amounts of MA adsorbed on Fe oxides and Fe dissolved by MA from Fe oxides depended on MA concentration, pH, and the type and the amount of Fe oxides added in the system. The Fe dissolution processes from Fe oxides by MA could involve two factors, namely (i) the complexation of MA with Fe exposed on the surface of Fe oxides by ligand exchange; and (ii) the release of MAFe complexes from adsorption sites on Fe oxides by nucleophilic substitution. Our data further clarify the chemistry of Fe nutrition of graminaceous plants in Fe-deficiency-causing soils..
2. K INOUE, S HIRADATE, S TAKAGI, INTERACTION OF MUGINEIC ACID WITH SYNTHETICALLY PRODUCED IRON-OXIDES, SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, Vol.57, No.5, pp.1254-1260, 1993.09, Interactions between mugineic acid (MA) purified from root washings of Fe-deficient barley (Hordeum vulgare L., cv. Minorimugi) and synthetically produced Fe oxides (goethite, hematite, lepidocrocite, and ferrihydrite) were studied in the equilibrium pH range of 3 to 11. The amount of MA adsorbed on Fe oxides was related to their specific surface area and followed the order: ferrihydrite > > goethite greater than or equal to lepidocrocite greater than or equal to hematite. The adsorption of MA on Fe oxides also decreased with increasing equilibrium pH and increased with increasing MA concentration. The MAFe complexes were also adsorbed on Fe oxides, especially on ferrihydrite and goethite, at pH 3 to 7. At pH > 10, however, MAFe complexes were decomposed to MA and Fe(OH)(3) colloids. The amount of Fe dissolved from Fe oxides by MA was in the following order: ferrihydrite > > lepidocrocite greater than or equal to hematite = goethite. The Fe dissolution from Fe oxides by MA was related to their crystallinity and the maximum amount of Fe dissolved by MA was in the pH range of 7 to 8. The amounts of MA adsorbed on Fe oxides and Fe dissolved by MA from Fe oxides depended on MA concentration, pH, and the type and the amount of Fe oxides added in the system. The Fe dissolution processes from Fe oxides by MA could involve two factors, namely (i) the complexation of MA with Fe exposed on the surface of Fe oxides by ligand exchange; and (ii) the release of MAFe complexes from adsorption sites on Fe oxides by nucleophilic substitution. Our data further clarify the chemistry of Fe nutrition of graminaceous plants in Fe-deficiency-causing soils..
3. S Hiradate, K Inoue, Determination of mugineic acid, 2'-deoxymugineic acid, 3-hydroxymugineic acid, and their iron complexes by ion-pair HPLC and colorimetric procedures, SOIL SCIENCE AND PLANT NUTRITION, 10.1080/00380768.1996.10416335, Vol.42, No.3, pp.659-665, 1996.09.
4. S Hiradate, K Inoue, Determination of mugineic acid, 2'-deoxymugineic acid, 3-hydroxymugineic acid, and their iron complexes by ion-pair HPLC and colorimetric procedures, SOIL SCIENCE AND PLANT NUTRITION, 10.1080/00380768.1996.10416335, Vol.42, No.3, pp.659-665, 1996.09.
5. Growth Inhibition and Fungicidal Activity of Volatile Compound from Brassica juncea on Fusarium oxysporum f. sp. spinaciae.
6. JF Ma, S Hiradate, K Nomoto, T Iwashita, H Matsumoto, Internal detoxification mechanism of Al in hydrangea - Identification of Al form in the leaves, PLANT PHYSIOLOGY, Vol.113, No.4, pp.1033-1039, 1997.04, An internal detoxification mechanism for Al was investigated in an Al-accumulating plant, hydrangea (Hydrangea macrophylla), focusing on Al forms present in the cells. The leaves of hydrangea contained as much as 15.7 mmol Al kg(-1) fresh weight, and more than two-thirds of the Al was found in the cell sap. Using Al-27-nuclear magnetic resonance, the dominant peak of Al was observed at a chemical shift of 11 to 12 parts per million in both intact leaves and the extracted cell sap, which is in good accordance with the chemical shift for the 1:1 Al-citrate complex. Purification of cell sap by molecular sieve chromatography (Sephadex G-10) combined with ion-exclusion chromatography indicated that Al in fractions with the same retention time as citric acid contributed to the observed Al-27 peak in the intact leaves. The molar ratio of Al to citric acid in the crude and purified cell sap approximated 1. The structure of the ligand chelated with Al was identified to be citric acid. Bioassay experiments showed that the purified Al complex from the cell sap did not inhibit root elongation of corn (Zea mays L.) and the viability of cells on the root tip surface was also not affected. These observations indicate that Al is bound to citric acid in the cells of hydrangea leaves..
7. JF Ma, S Hiradate, K Nomoto, T Iwashita, H Matsumoto, Internal detoxification mechanism of Al in hydrangea - Identification of Al form in the leaves, PLANT PHYSIOLOGY, Vol.113, No.4, pp.1033-1039, 1997.04, An internal detoxification mechanism for Al was investigated in an Al-accumulating plant, hydrangea (Hydrangea macrophylla), focusing on Al forms present in the cells. The leaves of hydrangea contained as much as 15.7 mmol Al kg(-1) fresh weight, and more than two-thirds of the Al was found in the cell sap. Using Al-27-nuclear magnetic resonance, the dominant peak of Al was observed at a chemical shift of 11 to 12 parts per million in both intact leaves and the extracted cell sap, which is in good accordance with the chemical shift for the 1:1 Al-citrate complex. Purification of cell sap by molecular sieve chromatography (Sephadex G-10) combined with ion-exclusion chromatography indicated that Al in fractions with the same retention time as citric acid contributed to the observed Al-27 peak in the intact leaves. The molar ratio of Al to citric acid in the crude and purified cell sap approximated 1. The structure of the ligand chelated with Al was identified to be citric acid. Bioassay experiments showed that the purified Al complex from the cell sap did not inhibit root elongation of corn (Zea mays L.) and the viability of cells on the root tip surface was also not affected. These observations indicate that Al is bound to citric acid in the cells of hydrangea leaves..
8. M Nakayama, M Koshioka, M Shibata, S Hiradate, H Sugie, M Yamaguchi, Identification of cyanidin 3-O-(3'',6''-beta-dimalonyl-beta-glucopyranoside) as a flower pigment of chrysanthemum (Dendranthema grandiflorum), BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 10.1271/bbb.61.1607, Vol.61, No.9, pp.1607-1608, 1997.09, It had been suggested that cyanidin 3-O-(6 ''-O-monomalonyl-beta-glucopyranoside) and another unknown compound occur as major pigments in the purplish-red flower of chrysanthemum (Dendranthema grandiflorum). We determined the structure of the unknown compound as cyanidin 3-O-(3 '',6 ''-O-dimalonyl-beta-glucopyranoside) by FAB-MS and H-1-NMR. This is the first report of the identification of the cyanidin 3-dimalonyl glucoside as a flower pigment..
9. M Nakayama, M Koshioka, M Shibata, S Hiradate, H Sugie, M Yamaguchi, Identification of cyanidin 3-O-(3'',6''-beta-dimalonyl-beta-glucopyranoside) as a flower pigment of chrysanthemum (Dendranthema grandiflorum), BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 10.1271/bbb.61.1607, Vol.61, No.9, pp.1607-1608, 1997.09, It had been suggested that cyanidin 3-O-(6 ''-O-monomalonyl-beta-glucopyranoside) and another unknown compound occur as major pigments in the purplish-red flower of chrysanthemum (Dendranthema grandiflorum). We determined the structure of the unknown compound as cyanidin 3-O-(3 '',6 ''-O-dimalonyl-beta-glucopyranoside) by FAB-MS and H-1-NMR. This is the first report of the identification of the cyanidin 3-dimalonyl glucoside as a flower pigment..
10. JF Ma, SJ Zheng, H Matsumoto, S Hiradate, Detoxifying aluminium with buckwheat, NATURE, Vol.390, No.6660, pp.569-570, 1997.12.
11. Mode of action of L-DOPA on plant growth : Effects on suger metabolism and composition of amino acids.
12. UK Saha, S Hiradate, K Inoue, Retention of phosphate by hydroxyaluminosilicate- and hydroxyaluminum-montmorillonite complexes, SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, 10.2136/sssaj1998.03615995006200040011x, Vol.62, No.4, pp.922-929, 1998.07, Hydroxyaluminosilicate (HAS) ions were prepared from solutions containing hydroxyaluminum (HyA) ions and orthosilicic acids at an Al concentration of approximate to 4 mill; Si/Al molar ratios of 0, 0.25, 0.5, and 1.0; and NaOH/Al molar ratios of 1.0, 2.0, and 2.5. Phosphate retention behavior of montmorillonite (Mt) carrying nonexchangeably adsorbed HyA, HAS ions, or both (HyA/HAS-Mt complexes) was studied at equilibrating solution pH of approximate to 5.0, The HyA/HAS-Mt complexes showed larger phosphate retention capacities than untreated Mt. Retention of phosphate by these complexes at 0.5 to 50 mM initial P concentrations decreased with increasing NaOH/Al and Si/Al ratios of the hydroxy materials adsorbed on hit. Phosphate, probably retained initially through surface complexation and ligand exchange reactions principally with OH or OH2 groups, coordinated with Al atoms at the broken edges of HyA or HAS polymers adsorbed on the external planar surfaces and in the interlayer spaces of Mt. This was followed by expulsion of the phosphated hydroxy materials from the Mt interlayers to the ambient solution, and finally, precipitation as amorphous Al-phosphate solid phases. Results of this study thus merit attention in P-fertility management as well as indicate a probable P-induced weathering process in acidic nonallophanic Andisols and in Red-Yellow soils (Hapludalfs and Hapludults) with a predominance of hydroxy-interlayered minerals..
13. UK Saha, S Hiradate, K Inoue, Retention of phosphate by hydroxyaluminosilicate- and hydroxyaluminum-montmorillonite complexes, SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, 10.2136/sssaj1998.03615995006200040011x, Vol.62, No.4, pp.922-929, 1998.07, Hydroxyaluminosilicate (HAS) ions were prepared from solutions containing hydroxyaluminum (HyA) ions and orthosilicic acids at an Al concentration of approximate to 4 mill; Si/Al molar ratios of 0, 0.25, 0.5, and 1.0; and NaOH/Al molar ratios of 1.0, 2.0, and 2.5. Phosphate retention behavior of montmorillonite (Mt) carrying nonexchangeably adsorbed HyA, HAS ions, or both (HyA/HAS-Mt complexes) was studied at equilibrating solution pH of approximate to 5.0, The HyA/HAS-Mt complexes showed larger phosphate retention capacities than untreated Mt. Retention of phosphate by these complexes at 0.5 to 50 mM initial P concentrations decreased with increasing NaOH/Al and Si/Al ratios of the hydroxy materials adsorbed on hit. Phosphate, probably retained initially through surface complexation and ligand exchange reactions principally with OH or OH2 groups, coordinated with Al atoms at the broken edges of HyA or HAS polymers adsorbed on the external planar surfaces and in the interlayer spaces of Mt. This was followed by expulsion of the phosphated hydroxy materials from the Mt interlayers to the ambient solution, and finally, precipitation as amorphous Al-phosphate solid phases. Results of this study thus merit attention in P-fertility management as well as indicate a probable P-induced weathering process in acidic nonallophanic Andisols and in Red-Yellow soils (Hapludalfs and Hapludults) with a predominance of hydroxy-interlayered minerals..
14. S Hiradate, K Inoue, Interaction of mugineic acid with iron (hydr)oxides: Sulfate and phosphate influences, SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, Vol.62, No.1, pp.159-165, 1998.01, Interactions of 100 mu mol L-1 mugineic acid (MA) with synthetically produced Fe (hydr)oxides (goethite, hematite, lepidocrocite, and ferrihydrite) as influenced by 100 mmol L-1 SO42- and phosphate were studied at equilibrium in the pH range from 3 to 11, In the presence of SO42-, the concentrations of total MA [i.e., free MA + Fe(III)-MA complexes] and Fe(III) dissolved by MA in the filtrates were higher than those in the presence of 100 mmol L-1 Cl- at pH < 7. Sulfate increased the formation of Fe(III)-MA complexes indirectly by reducing the adsorption of MA and Fe(III)-MA by the Fe (hydr)oxides. The adsorption of MA by the Fe (hydr)oxides and consequently the MA-promoted dissolution of Fe(III) from ferrihydrite and lepidocrocite were greatly inhibited by the adsorption of phosphate. The slight dissolution of Fe(III) between pH 5 and 9 is partly attributed to the formation of soluble Fe(III)-phosphate complexes. Although MA does not react directly with Fe (hydr)oxides in the presence of excess phosphate, MA mould promote the dissolution reaction of Fe(III) by phosphate, The sequence of adsorption affinity for the Fe (hydr)oxides was found to be: phosphate >> MA > Fe(III)-MA, SO42-> Cl-. Our results suggest that SO42- and especially phosphate applied as fertilizers may inhibit the MA-promoted dissolution of Fe(III) from Fe (hydr)oxides in soils mainly by displacement of MA from the surface of Fe (hydr)oxides..
15. S Hiradate, K Inoue, Interaction of mugineic acid with iron (hydr)oxides: Sulfate and phosphate influences, SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, Vol.62, No.1, pp.159-165, 1998.01, Interactions of 100 mu mol L-1 mugineic acid (MA) with synthetically produced Fe (hydr)oxides (goethite, hematite, lepidocrocite, and ferrihydrite) as influenced by 100 mmol L-1 SO42- and phosphate were studied at equilibrium in the pH range from 3 to 11, In the presence of SO42-, the concentrations of total MA [i.e., free MA + Fe(III)-MA complexes] and Fe(III) dissolved by MA in the filtrates were higher than those in the presence of 100 mmol L-1 Cl- at pH < 7. Sulfate increased the formation of Fe(III)-MA complexes indirectly by reducing the adsorption of MA and Fe(III)-MA by the Fe (hydr)oxides. The adsorption of MA by the Fe (hydr)oxides and consequently the MA-promoted dissolution of Fe(III) from ferrihydrite and lepidocrocite were greatly inhibited by the adsorption of phosphate. The slight dissolution of Fe(III) between pH 5 and 9 is partly attributed to the formation of soluble Fe(III)-phosphate complexes. Although MA does not react directly with Fe (hydr)oxides in the presence of excess phosphate, MA mould promote the dissolution reaction of Fe(III) by phosphate, The sequence of adsorption affinity for the Fe (hydr)oxides was found to be: phosphate >> MA > Fe(III)-MA, SO42-> Cl-. Our results suggest that SO42- and especially phosphate applied as fertilizers may inhibit the MA-promoted dissolution of Fe(III) from Fe (hydr)oxides in soils mainly by displacement of MA from the surface of Fe (hydr)oxides..
16. JF Ma, S Hiradate, H Matsumoto, High aluminum resistance in buckwheat - II. Oxalic acid detoxifies aluminum internally, PLANT PHYSIOLOGY, 10.1104/pp.117.3.753, Vol.117, No.3, pp.753-759, 1998.07, which Buckwheat (Fagopyrum esculentum Moench. cv Jianxi): shows high Al resistance, accumulates Al in the leaves. The Internal detoxification mechanism was studied by purifying and identifying Al complexes in the leaves and roofs. About 90% of Al accumulated in the leaves was found in the cell sap, in which the dominant organic acid was oxalic acid. Purification of the Al complex in the cell sap of leaves by molecular-sieve chromatography resulted in a complex with a ratio of Al to oxalic acid of 1:3. A C-13-nuclear magnetic resonance study of the purified cell sap revealed only one signal at a chemical shift 164.4 ppm, which was assigned to the Al-chelated carboxylic group of oxalic acid. A Al-27-nuclear magnetic resonance analysis revealed one major signal at the chemical shift of 16.0 to 17.0 ppm, with a minor signal at the chemical shift of 11.0 to 12 ppm in both the intact roots and their cell sap, which is consistent with the Al-oxalate complexes at 1:3 and 2:2 ratios, respectively. The purified cell sap was not phytotoxic to root elongation in corn (Zea mays). All of these results indicate that Al tolerance in the roots and leaves of buckwheat is achieved by the formation of a nonphytotoxic Al-oxalate (1:3) complex..
17. JF Ma, S Hiradate, H Matsumoto, High aluminum resistance in buckwheat - II. Oxalic acid detoxifies aluminum internally, PLANT PHYSIOLOGY, 10.1104/pp.117.3.753, Vol.117, No.3, pp.753-759, 1998.07, which Buckwheat (Fagopyrum esculentum Moench. cv Jianxi): shows high Al resistance, accumulates Al in the leaves. The Internal detoxification mechanism was studied by purifying and identifying Al complexes in the leaves and roofs. About 90% of Al accumulated in the leaves was found in the cell sap, in which the dominant organic acid was oxalic acid. Purification of the Al complex in the cell sap of leaves by molecular-sieve chromatography resulted in a complex with a ratio of Al to oxalic acid of 1:3. A C-13-nuclear magnetic resonance study of the purified cell sap revealed only one signal at a chemical shift 164.4 ppm, which was assigned to the Al-chelated carboxylic group of oxalic acid. A Al-27-nuclear magnetic resonance analysis revealed one major signal at the chemical shift of 16.0 to 17.0 ppm, with a minor signal at the chemical shift of 11.0 to 12 ppm in both the intact roots and their cell sap, which is consistent with the Al-oxalate complexes at 1:3 and 2:2 ratios, respectively. The purified cell sap was not phytotoxic to root elongation in corn (Zea mays). All of these results indicate that Al tolerance in the roots and leaves of buckwheat is achieved by the formation of a nonphytotoxic Al-oxalate (1:3) complex..
18. S Hiradate, K Inoue, Dissolution of iron from iron (hydr)oxides by mugineic acid, SOIL SCIENCE AND PLANT NUTRITION, 10.1080/00380768.1998.10414453, Vol.44, No.3, pp.305-313, 1998.09, Mugineic acid (MA; (2S, 2'S, 3'S, 3 " S)-N-[3-carboxy-3-(3-carboxy-3-hydroxy-propylamino) -2-hydroxypropyl]-azetidine-2-carboxylic acid), a multidentate complexing agent, is exuded by the roots of graminaceous plants (e.g. barley) growing under Fe-deficient conditions. The nature of the interactions of MA with Fe (hydr)oxide minerals in soils is thus of considerable practical importance. To examine the availability of RIA in dissolving Fe (hydr)oxides, we investigated the amounts of Fe dissolved from 24 samples of Fe (hydr)oxides by 100 mu M MA (Fe-MA) and 200 mM NH4-oxalate (Fe-0).
The Fe-0 values were much larger than the Fe-MA ones, though the crystallinity of the Fe (hydr)oxides was a significant factor. For Fe (hydr)oxides consisting of goethite, hematite, ferrihydrite, and their mixture, Fe-MA increased with the increase of Fe-0, indicating that Fe-MA would be correlated with Fee, that is the amount of short-range ordered Fe minerals including ferrihydrite. For goethite, hematite, magnetite, maghemite, and lepidocrocite with a high crystallinity, MA was relatively ineffective in dissolving Fe, although a part of crystalline magnetite, maghemite, and lepidocrocite could be dissolved by NH4-oxalate. For soils containing significant amounts of magnetite, maghemite, lepidocrocite, it is unlikely therefore that Fe-0 would be a useful indicator of plant-available Fe..
19. S Hiradate, K Inoue, Dissolution of iron from iron (hydr)oxides by mugineic acid, SOIL SCIENCE AND PLANT NUTRITION, 10.1080/00380768.1998.10414453, Vol.44, No.3, pp.305-313, 1998.09, Mugineic acid (MA; (2S, 2'S, 3'S, 3 " S)-N-[3-carboxy-3-(3-carboxy-3-hydroxy-propylamino) -2-hydroxypropyl]-azetidine-2-carboxylic acid), a multidentate complexing agent, is exuded by the roots of graminaceous plants (e.g. barley) growing under Fe-deficient conditions. The nature of the interactions of MA with Fe (hydr)oxide minerals in soils is thus of considerable practical importance. To examine the availability of RIA in dissolving Fe (hydr)oxides, we investigated the amounts of Fe dissolved from 24 samples of Fe (hydr)oxides by 100 mu M MA (Fe-MA) and 200 mM NH4-oxalate (Fe-0).
The Fe-0 values were much larger than the Fe-MA ones, though the crystallinity of the Fe (hydr)oxides was a significant factor. For Fe (hydr)oxides consisting of goethite, hematite, ferrihydrite, and their mixture, Fe-MA increased with the increase of Fe-0, indicating that Fe-MA would be correlated with Fee, that is the amount of short-range ordered Fe minerals including ferrihydrite. For goethite, hematite, magnetite, maghemite, and lepidocrocite with a high crystallinity, MA was relatively ineffective in dissolving Fe, although a part of crystalline magnetite, maghemite, and lepidocrocite could be dissolved by NH4-oxalate. For soils containing significant amounts of magnetite, maghemite, lepidocrocite, it is unlikely therefore that Fe-0 would be a useful indicator of plant-available Fe..
20. S Hiradate, S Taniguchi, K Sakurai, Aluminum speciation in aluminum-silica solutions and potassium chloride extracts of acidic soils, SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, Vol.62, No.3, pp.630-636, 1998.05, To differentiate chemical species of Al in soil solutions, a method using nuclear magnetic resonance (NMR) was applied to laboratory preparations of hydroxyaluminum (HyA) and hydroxyaluminosilicate (HAS) ions ([OH]/[Al] = 2.0), and 1 M KCl extracts from acidic soils. The Al in a Al-OH-Si(OH)(4) mixture was separated into three fractions: Al-13([AlO4Al12(OH)(24)(H2O)(12)](7+)), Al-SYM, and Al-NON. The Al-13 and Al-SYM were quantitatively determined by Al-27-NMR at 63 and 0 ppm, respectively. The Al-NON was defined as the Al that cannot be determined by Al-27-NMR. The Al-SYM was attributed to electrically symmetric octahedral Al including monomer land dimer) HyA ions, and the Al-NON was attributed to electrically asymmetric Al including HAS and polymer HyA ions. The concentrations of Al-13 decreased with increasing Si/Al molar ratio of the mixed solutions, and Al-13 was not detected at Si/Al greater than or equal to 0.28. With increasing Si/Al molar ratio, the concentration of Al-SYM increased slightly, while Al-NON increased significantly. In the KCL extracts from soils, the Al-13 was not detected at all. This result suggests that Al-13 is not formed in these soils, or that the persistence of Al-13 in the soil solution is strongly inhibited by adsorption or precipitation reactions. The presence of organically complexed Al (Al-ORG) was also directly detected in KCL extracts from upper horizons by Al-27-NMR spectra. The chemical shift of resonance peak of Al-ORG was close to that of the 1:1 complex of AL oxalate. On average, 92 and 96% of the KCl-exchangeable Al existed as Al-SYM and Al-SYM plus Al-ORG respectively..
21. S Hiradate, S Taniguchi, K Sakurai, Aluminum speciation in aluminum-silica solutions and potassium chloride extracts of acidic soils, SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, Vol.62, No.3, pp.630-636, 1998.05, To differentiate chemical species of Al in soil solutions, a method using nuclear magnetic resonance (NMR) was applied to laboratory preparations of hydroxyaluminum (HyA) and hydroxyaluminosilicate (HAS) ions ([OH]/[Al] = 2.0), and 1 M KCl extracts from acidic soils. The Al in a Al-OH-Si(OH)(4) mixture was separated into three fractions: Al-13([AlO4Al12(OH)(24)(H2O)(12)](7+)), Al-SYM, and Al-NON. The Al-13 and Al-SYM were quantitatively determined by Al-27-NMR at 63 and 0 ppm, respectively. The Al-NON was defined as the Al that cannot be determined by Al-27-NMR. The Al-SYM was attributed to electrically symmetric octahedral Al including monomer land dimer) HyA ions, and the Al-NON was attributed to electrically asymmetric Al including HAS and polymer HyA ions. The concentrations of Al-13 decreased with increasing Si/Al molar ratio of the mixed solutions, and Al-13 was not detected at Si/Al greater than or equal to 0.28. With increasing Si/Al molar ratio, the concentration of Al-SYM increased slightly, while Al-NON increased significantly. In the KCL extracts from soils, the Al-13 was not detected at all. This result suggests that Al-13 is not formed in these soils, or that the persistence of Al-13 in the soil solution is strongly inhibited by adsorption or precipitation reactions. The presence of organically complexed Al (Al-ORG) was also directly detected in KCL extracts from upper horizons by Al-27-NMR spectra. The chemical shift of resonance peak of Al-ORG was close to that of the 1:1 complex of AL oxalate. On average, 92 and 96% of the KCl-exchangeable Al existed as Al-SYM and Al-SYM plus Al-ORG respectively..
22. Screening of natural biologically active substances with plant growth inhibitory effects-Evaluation of candidates of allelochemicals.
23. S Hiradate, H Yada, T Ishii, N Nakajima, M Ohnishi-Kameyama, H Sugie, S Zungsontiporn, Y Fujii, Three plant growth inhibiting saponins from Duranta repens, PHYTOCHEMISTRY, 10.1016/S0031-9422(99)00408-2, Vol.52, No.7, pp.1223-1228, 1999.12, Three new triterpenoid-type saponins were isolated from leaves of Duranta repens using plant growth inhibiting activity against seedlings of Brassica juncea var. cernua as a guide for fractionation. The structures of these compounds were elucidated as polygalacic acid-3-O-beta-D-glucopyranosido-28-O-[alpha-L-rhamnopyranosyl-(1-->3')-beta-D-apiofuranosyl-(1--->4)-alpha-L-rhamnopyranosyl-(1 -->2)-beta-L-arabinopyranoside] (durantanin I), polygalacic acid-3-O-beta-D-glucopyranosido-28-O-[alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1 --> 4)-[beta-D-apiofuranosyl-(1 --> 3)]-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-L-arabinopyranoside] (durantanin II), and polygalacic acid-3-O-beta-D-glucopyranosido-28-O-[alpha-L-rhamnopyranosyl-(1 --> 3)-beta-D-xylopyranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-L-arabinopyranoside] (durantanin III). (C) 1999 Elsevier Science Ltd. All rights reserved..
24. S Hiradate, H Yada, T Ishii, N Nakajima, M Ohnishi-Kameyama, H Sugie, S Zungsontiporn, Y Fujii, Three plant growth inhibiting saponins from Duranta repens, PHYTOCHEMISTRY, 10.1016/S0031-9422(99)00408-2, Vol.52, No.7, pp.1223-1228, 1999.12, Three new triterpenoid-type saponins were isolated from leaves of Duranta repens using plant growth inhibiting activity against seedlings of Brassica juncea var. cernua as a guide for fractionation. The structures of these compounds were elucidated as polygalacic acid-3-O-beta-D-glucopyranosido-28-O-[alpha-L-rhamnopyranosyl-(1-->3')-beta-D-apiofuranosyl-(1--->4)-alpha-L-rhamnopyranosyl-(1 -->2)-beta-L-arabinopyranoside] (durantanin I), polygalacic acid-3-O-beta-D-glucopyranosido-28-O-[alpha-L-rhamnopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1 --> 4)-[beta-D-apiofuranosyl-(1 --> 3)]-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-L-arabinopyranoside] (durantanin II), and polygalacic acid-3-O-beta-D-glucopyranosido-28-O-[alpha-L-rhamnopyranosyl-(1 --> 3)-beta-D-xylopyranosyl-(1 --> 4)-alpha-L-rhamnopyranosyl-(1 --> 2)-beta-L-arabinopyranoside] (durantanin III). (C) 1999 Elsevier Science Ltd. All rights reserved..
25. M Toma, S Hiradate, M Saigusa, Chemical species of Al in a gypsum-treated Kitakami andosol, SOIL SCIENCE AND PLANT NUTRITION, Vol.45, No.2, pp.279-285, 1999.06, To examine the possibility that the Al-13 polymer ( [AIO(4)Al(12)(OH)(24)(H2O)(12)](7+)) could be formed in soils after gypsum application, an analytical method using a cation exchange resin and Al-27 nuclear magnetic resonance (NMR) spectroscopy was applied to gypsum-treated Kitakami Andosol (fine, mixed, mesic, Andic Dystrochrept), The NMR spectra of the cation exchange resins which retained artificially synthesized hydroxy-Al, showed two broad peaks at 0 and 63 ppm, These results indicated that monomer and/or dimer Al and Al-13 polymers adsorbed on the cation exchange resin could be detected with Al-27 NMR, The amount of polymer Al increased by gypsum application in the Kitakami soil. The NMR spectrum of this resin showed only one peak at 0 ppm indicating that the polymer Al formed in the gypsum treated Kitakami soil was not the Al-13 polymer..
26. A Ichikawa, S Hiradate, A Sugio, S Kuwahara, M Watanabe, N Harada, Absolute configuration of 2-hydroxy-2-(1-naphthyl)propionic acid as determined by the H-1 NMR anisotropy method, TETRAHEDRON-ASYMMETRY, 10.1016/S0957-4166(99)00451-6, Vol.10, No.21, pp.4075-4078, 1999.10, Enantiopure 2-hydroxy-2-(1-naphthyl)propionic acid (+)-2 was prepared by the stereoselective Grignard reaction of 1-naphthylmagnesium bromide with (1R,3R,4S)-menthyl pyruvate 3 or (1R,3R,4S)-8-phenylmenthyl pyruvate 4, and the absolute configuration of acid (+)-2 was unambiguously determined to be S by the H-1 NMR anisotropy method. (C) 1999 Elsevier Science Ltd. All rights reserved..
27. A Ichikawa, S Hiradate, A Sugio, S Kuwahara, M Watanabe, N Harada, Absolute configuration of 2-hydroxy-2-(1-naphthyl)propionic acid as determined by the H-1 NMR anisotropy method, TETRAHEDRON-ASYMMETRY, 10.1016/S0957-4166(99)00451-6, Vol.10, No.21, pp.4075-4078, 1999.10, Enantiopure 2-hydroxy-2-(1-naphthyl)propionic acid (+)-2 was prepared by the stereoselective Grignard reaction of 1-naphthylmagnesium bromide with (1R,3R,4S)-menthyl pyruvate 3 or (1R,3R,4S)-8-phenylmenthyl pyruvate 4, and the absolute configuration of acid (+)-2 was unambiguously determined to be S by the H-1 NMR anisotropy method. (C) 1999 Elsevier Science Ltd. All rights reserved..
28. Allelopathy of Lycoris radiata : Identification of lycorine and crinine as allelochemicals.
29. Study on plant growth inhibitory effect of L-canavanine.
30. Isolation of Toxins Extracted from Lesions of Mulberry Leaves Inoculated with Colletorichum dematium, and Role of the Toxins in Pathogenicity.
31. XF Li, JF Ma, S Hiradate, H Matsumoto, Mucilage strongly binds aluminum but does not prevent roots from aluminum injury in Zea mays, PHYSIOLOGIA PLANTARUM, 10.1034/j.1399-3054.2000.108002152.x, Vol.108, No.2, pp.152-160, 2000.02, The possible role of mucilage in protecting roots from aluminum (Al) injury mas investigated in Zea mays L. (cv. Golden Cross Bantam), focusing on binding of Al with mucilage and effects of mucilage on Al toxicity. Al mas bound to mucilage after the treatment of roots with 10-50 mu M Al for 1 h and 30 mu M Al for 30, 60, 90 and 120 min. Using molecular sieve chromatography (Sephadex G-100), Al was co-eluted with a high molecular mass sugar and a low molecular mass sugar. The difficulty in desorbing Al from mucilage with organic acids confirmed the strong binding strength of Al by mucilage revealed by (27)Al nuclear magnetic resonance (NMR). Al could not be desorbed completely by succinic, melic, oxalic and citric acid at a molar ratio of 1:1. It could only be completely removed by oxalic acid at a molar ratio of 20:1 (oxalate:Al). Bioassay experiments showed that cell viability and callose formation were unaffected by Al bound to mucilage. However, mucilage deprived roots had only 0.21-0.59 nmol apex(-1) higher Al content than control roots after treatment with 30 mu M Al for 1, 1.5 and 2 h. Moreover, inhibition of root elongation by 5 mu M Al for 6, 12, 24 and 36 h was independent of the presence or absence of mucilage prior to the Al treatment. These results indicate that although mucilage affects the accumulation of Al by roots, it does not confer Al resistance to Z. mays root apices..
32. XF Li, JF Ma, S Hiradate, H Matsumoto, Mucilage strongly binds aluminum but does not prevent roots from aluminum injury in Zea mays, PHYSIOLOGIA PLANTARUM, 10.1034/j.1399-3054.2000.108002152.x, Vol.108, No.2, pp.152-160, 2000.02, The possible role of mucilage in protecting roots from aluminum (Al) injury mas investigated in Zea mays L. (cv. Golden Cross Bantam), focusing on binding of Al with mucilage and effects of mucilage on Al toxicity. Al mas bound to mucilage after the treatment of roots with 10-50 mu M Al for 1 h and 30 mu M Al for 30, 60, 90 and 120 min. Using molecular sieve chromatography (Sephadex G-100), Al was co-eluted with a high molecular mass sugar and a low molecular mass sugar. The difficulty in desorbing Al from mucilage with organic acids confirmed the strong binding strength of Al by mucilage revealed by (27)Al nuclear magnetic resonance (NMR). Al could not be desorbed completely by succinic, melic, oxalic and citric acid at a molar ratio of 1:1. It could only be completely removed by oxalic acid at a molar ratio of 20:1 (oxalate:Al). Bioassay experiments showed that cell viability and callose formation were unaffected by Al bound to mucilage. However, mucilage deprived roots had only 0.21-0.59 nmol apex(-1) higher Al content than control roots after treatment with 30 mu M Al for 1, 1.5 and 2 h. Moreover, inhibition of root elongation by 5 mu M Al for 6, 12, 24 and 36 h was independent of the presence or absence of mucilage prior to the Al treatment. These results indicate that although mucilage affects the accumulation of Al by roots, it does not confer Al resistance to Z. mays root apices..
33. JF Ma, S Hiradate, Form of aluminium for uptake and translocation in buckwheat (Fagopyrum esculentum Moench), PLANTA, 10.1007/s004250000292, Vol.211, No.3, pp.355-360, 2000.08, The forms of Al for uptake by the roots and translocation from the root to the shoot were investigated in a buckwheat (Fagopyrum esculentum Moench, cv. Jianxi) that accumulates Al in its leaves. The Al concentration ill the xylem sap was 15-fold higher in the plants exposed to AlCl3 than in those exposed to an Al-oxalate (1:3) complex, suggesting that the roots take up Al in the ionic form. The Al concentration in the xylem sap was 4-fold higher than that in the external solution after a 1-h exposure to AlCl3 solution and 10-fold higher after a 2-h exposure. The Al concentration in the xylem sap increased with increasing Al concentration in the external solution. The Al uptake was not affected by a respiratory inhibitor, hydroxylamine, but significantly inhibited by the addition of La. These results suggest that Al uptake by the root is a passive process, and La3+ competes for the binding sites for Al3+ on the plasma membrane. The form of Al in the xylem sap was identified by Al-27-nuclear magnetic resonance analysis. The chemical shift of Al-27 in the xylem sap was around 10.9 ppm, which is consistent with that of the Al-citrate complex. Furthermore, the dominant organic acid in the xylem sag was citric acid, indicating that Al was translocated in the form of Al-citrate complex. Because Al is present as Al-oxalate (1:3) in the root, the present data show that ligand exchange from oxalate to citrate occurs before Al is released to xylem..
34. JF Ma, S Hiradate, Form of aluminium for uptake and translocation in buckwheat (Fagopyrum esculentum Moench), PLANTA, 10.1007/s004250000292, Vol.211, No.3, pp.355-360, 2000.08, The forms of Al for uptake by the roots and translocation from the root to the shoot were investigated in a buckwheat (Fagopyrum esculentum Moench, cv. Jianxi) that accumulates Al in its leaves. The Al concentration ill the xylem sap was 15-fold higher in the plants exposed to AlCl3 than in those exposed to an Al-oxalate (1:3) complex, suggesting that the roots take up Al in the ionic form. The Al concentration in the xylem sap was 4-fold higher than that in the external solution after a 1-h exposure to AlCl3 solution and 10-fold higher after a 2-h exposure. The Al concentration in the xylem sap increased with increasing Al concentration in the external solution. The Al uptake was not affected by a respiratory inhibitor, hydroxylamine, but significantly inhibited by the addition of La. These results suggest that Al uptake by the root is a passive process, and La3+ competes for the binding sites for Al3+ on the plasma membrane. The form of Al in the xylem sap was identified by Al-27-nuclear magnetic resonance analysis. The chemical shift of Al-27 in the xylem sap was around 10.9 ppm, which is consistent with that of the Al-citrate complex. Furthermore, the dominant organic acid in the xylem sag was citric acid, indicating that Al was translocated in the form of Al-citrate complex. Because Al is present as Al-oxalate (1:3) in the root, the present data show that ligand exchange from oxalate to citrate occurs before Al is released to xylem..
35. S Hiradate, K Inoue, Dissolution of iron by mugineic acid from soils and comparison with DTPA soil test, SOIL SCIENCE AND PLANT NUTRITION, 10.1080/00380768.2000.10409132, Vol.46, No.3, pp.673-681, 2000.09, Mugineic acid (MA), which is a multidentate phytosiderophore, is exuded to the rhizosphere by the roots of graminaceous plants (e.g. barley) growing under Fe-deficient conditions, resulting in the dissolution of Fe as a form of MA-Fe-III complex (MAFe). To clarify the effects of soil chemical properties on the amount of Fe dissolved by MA, an experiment to study the reaction of RIA using 38 soil samples was conducted, and the concentrations of free MA (uncomplexed and non-adsorbed MA) and MAFe in solution and the amounts of MA adsorbed on the soils were determined after the reaction. Soil pH value was a good indicator to predict the behavior of MA in soils. A large proportion of added MA was adsorbed on soils or formed MAFe in solution in acidic soils, whereas it did not react with soils and occurred as free MA in alkaline soils. These features were in good agreement with the interaction of MA with Fe (hydr)oxides, as reported in previous papers. Other soil chemical properties, such as soil organic carbon (SOC) content and the amount of amorphous (hydr)oxide components, also affected the behavior of MA in the soils, The Fe dissolution ability of MA was compared with that of diethylenetriaminepentaacetic acid (DTPA) soil test. Although the amounts of extractable Fe were similar between the MA extraction and DTPA soil test, factors influencing the amount of Fe dissolved (formation constant with Fe-III, reaction pH, rate constant, etc.) were different between both chelating compounds..
36. S Hiradate, K Inoue, Dissolution of iron by mugineic acid from soils and comparison with DTPA soil test, SOIL SCIENCE AND PLANT NUTRITION, 10.1080/00380768.2000.10409132, Vol.46, No.3, pp.673-681, 2000.09, Mugineic acid (MA), which is a multidentate phytosiderophore, is exuded to the rhizosphere by the roots of graminaceous plants (e.g. barley) growing under Fe-deficient conditions, resulting in the dissolution of Fe as a form of MA-Fe-III complex (MAFe). To clarify the effects of soil chemical properties on the amount of Fe dissolved by MA, an experiment to study the reaction of RIA using 38 soil samples was conducted, and the concentrations of free MA (uncomplexed and non-adsorbed MA) and MAFe in solution and the amounts of MA adsorbed on the soils were determined after the reaction. Soil pH value was a good indicator to predict the behavior of MA in soils. A large proportion of added MA was adsorbed on soils or formed MAFe in solution in acidic soils, whereas it did not react with soils and occurred as free MA in alkaline soils. These features were in good agreement with the interaction of MA with Fe (hydr)oxides, as reported in previous papers. Other soil chemical properties, such as soil organic carbon (SOC) content and the amount of amorphous (hydr)oxide components, also affected the behavior of MA in the soils, The Fe dissolution ability of MA was compared with that of diethylenetriaminepentaacetic acid (DTPA) soil test. Although the amounts of extractable Fe were similar between the MA extraction and DTPA soil test, factors influencing the amount of Fe dissolved (formation constant with Fe-III, reaction pH, rate constant, etc.) were different between both chelating compounds..
37. S Yoshida, S Hiradate, Y Fujii, A Shirata, Colletotrichum dematium produces phytotoxins in anthracnose lesions of mulberry leaves, PHYTOPATHOLOGY, 10.1094/PHYTO.2000.90.3.285, Vol.90, No.3, pp.285-291, 2000.03, Colletotrichum dematium, the causal agent of mulberry anthracnose, was examined to produce phytotoxins in vitro and in planta. Raw and autoclaved mulberry leaves infected with the fungus, as well as the fungus incubated with several solid or liquid media, were extracted with acetone. Extracts obtained from the fungus grown on raw and autoclaved mulberry leaves caused brown necrotic lesions on susceptible mulberry leaves when they were placed (10 mu l) on the wounded adaxial surface. Whereas, no extracts obtained from media, except inoculated medium containing homogenized mulberry leaves, induced the necrosis, suggesting that the fungus produced phytotoxins in planta and that some components in mulberry leaves may be indispensable substrates for producing the toxins. The phytotoxins obtained from the diseased leaves induced necrosis on nonhost plants leaves as well as on mulberry leaves. The toxins were present in the border of anthracnose lesions on the leaves, and the sensitivity to the toxin correlated with that to the fungus infection in each susceptible or resistant mulberry cultivar. These results suggest that the phytotoxins are host nonspecific and play a role in fungal pathogenesis in the development of the lesions. Four toxic compounds were isolated and purified from anthracnose lesions. However, due to the low yield, the chemical structure of the compounds could not be identified..
38. S Yoshida, S Hiradate, Y Fujii, A Shirata, Colletotrichum dematium produces phytotoxins in anthracnose lesions of mulberry leaves, PHYTOPATHOLOGY, 10.1094/PHYTO.2000.90.3.285, Vol.90, No.3, pp.285-291, 2000.03, Colletotrichum dematium, the causal agent of mulberry anthracnose, was examined to produce phytotoxins in vitro and in planta. Raw and autoclaved mulberry leaves infected with the fungus, as well as the fungus incubated with several solid or liquid media, were extracted with acetone. Extracts obtained from the fungus grown on raw and autoclaved mulberry leaves caused brown necrotic lesions on susceptible mulberry leaves when they were placed (10 mu l) on the wounded adaxial surface. Whereas, no extracts obtained from media, except inoculated medium containing homogenized mulberry leaves, induced the necrosis, suggesting that the fungus produced phytotoxins in planta and that some components in mulberry leaves may be indispensable substrates for producing the toxins. The phytotoxins obtained from the diseased leaves induced necrosis on nonhost plants leaves as well as on mulberry leaves. The toxins were present in the border of anthracnose lesions on the leaves, and the sensitivity to the toxin correlated with that to the fungus infection in each susceptible or resistant mulberry cultivar. These results suggest that the phytotoxins are host nonspecific and play a role in fungal pathogenesis in the development of the lesions. Four toxic compounds were isolated and purified from anthracnose lesions. However, due to the low yield, the chemical structure of the compounds could not be identified..
39. Akio Ichikawa, Syuntaro Hiradate, Akinori Sugio, Shunsuke Kuwahara, Masataka Watanabe, Nobuyuki Harada, Absolute configuration of 2-methoxy-2-(2-naphthyl)propionic acid as determined by the 1H NMR anisotropy method, Tetrahedron Asymmetry, 10.1016/S0957-4166(00)00233-0, Vol.11, No.13, pp.2669-2675, 2000.07, 2-Methoxy-2-(2-naphthyl)propionic acid 1 and 2-hydroxy-2-(2-naphthyl)propionic acid 2 were prepared by the Grignard reaction of 2-naphthylmagnesium bromide with (1R,2S,5R)-(-)-menthyl pyruvate. The absolute configurations of (+)-1 and (+)-2 were determined to be S by the 1H NMR anisotropy method. Copyright (C) 2000 Elsevier Science Ltd..
40. Akio Ichikawa, Syuntaro Hiradate, Akinori Sugio, Shunsuke Kuwahara, Masataka Watanabe, Nobuyuki Harada, Absolute configuration of 2-methoxy-2-(2-naphthyl)propionic acid as determined by the 1H NMR anisotropy method, Tetrahedron Asymmetry, 10.1016/S0957-4166(00)00233-0, Vol.11, No.13, pp.2669-2675, 2000.07, 2-Methoxy-2-(2-naphthyl)propionic acid 1 and 2-hydroxy-2-(2-naphthyl)propionic acid 2 were prepared by the Grignard reaction of 2-naphthylmagnesium bromide with (1R,2S,5R)-(-)-menthyl pyruvate. The absolute configurations of (+)-1 and (+)-2 were determined to be S by the 1H NMR anisotropy method. Copyright (C) 2000 Elsevier Science Ltd..
41. Allelopathy of black locust : Assessment of allelopathic activity and isolation of the allelochemicals..
42. Development of new bioassay for volatile allelochemicals : Dish-pack method..
43. Identification of methyl isothiocyanate as allelochemical of Spider Flower (Cleome spinosa)..
44. Soil Components in Molecular Level and Nano-Scale Interactions among the Components.
45. S Taniguchi, S Hiradate, K Sakurai, Speciation of hydroxyaluminosilicate and hydroxyaluminum ions as affected by the presence of montmorillonite: Extraction experiment with potassium chloride and speciation by Al-27-NMR, SOIL SCIENCE AND PLANT NUTRITION, Vol.47, No.2, pp.333-343, 2001.06, The changes of Al species in the presence of montmorillonite (Mt) with aging were investigated using Al-27-nuclear magnetic resonance and inductively coupled plasma atomic emission spectroscopy after extraction with 1 mol L-1 KCl. Composition of the Al species in a hydroxyaluminosilicate (HAS) solution with a Si/Al molar ratio of 0.63 without Mt was not appreciably affected by 42 d of aging, In the absence of Mt, the concentration of Al-13 ([AlO4Al12(OH)(24)-(H2O)(12)](7+)) in the HAS solution with a Si/Al molar ratio of 0.09 and hydroxyaluminum (HyA) solution decreased during 42d of aging, suggesting that degradation (or polymerization) of Al-13 took place upon aging, In the presence of Mt, Al-13 was adsorbed onto Mt from the HyA and HBS(0.09) solutions. The adsorbed Al-13 was partly recovered by 1 mol L-1 KCl from HyA- and HAS(0.09)-Mt complexes after 42 d of aging, suggesting that at least a part of the adsorbed Al-13 was exchangeable and the rest was considerably stabilized by adsorption onto Mt, The desorption ratios of Al from the HyA- and HAS(0.09)-Mt complexes accounted for 25 to 30% and 6 to 8% of total Al adsorbed, respectively. The species of Al desorbed from these complexes consisted mainly of Al-13 and Al-NON. The Al-NON was attributed to electrically asymmetric Al including HAS and/or polymer HyA ions..
46. S Wakamura, N Arakaki, M Yamamoto, S Hiradate, H Yasui, T Yasuda, T Ando, Posticlure: a novel trans-epoxide as a sex pheromone component of the tussock moth, Orgyia postica (Walker), TETRAHEDRON LETTERS, 10.1016/S0040-4039(00)02038-4, Vol.42, No.4, pp.687-689, 2001.01, A single EAG-active component was found in a pheromone extract from virgin females of the tussock moth, Orgyia postica. This compound nam ed posticlure possesses a trans-epoxy ring and was identified as (6Z,9Z,11S,12S)-11,12-epoxyhenicosa-6,9-diene by means of GC-MS, H-1 NMR and chiral HPLC analyses, and further chemical derivation followed by the GC-MS analysis. In a field test with. the pheromone synthesized stereoselectively, the male moths were specifically attracted to the (11S,12S)-isomer but not to the antipode. (C) 2001 Elsevier Science Ltd. All rights reserved..
47. S Wakamura, N Arakaki, M Yamamoto, S Hiradate, H Yasui, T Yasuda, T Ando, Posticlure: a novel trans-epoxide as a sex pheromone component of the tussock moth, Orgyia postica (Walker), TETRAHEDRON LETTERS, 10.1016/S0040-4039(00)02038-4, Vol.42, No.4, pp.687-689, 2001.01, A single EAG-active component was found in a pheromone extract from virgin females of the tussock moth, Orgyia postica. This compound nam ed posticlure possesses a trans-epoxy ring and was identified as (6Z,9Z,11S,12S)-11,12-epoxyhenicosa-6,9-diene by means of GC-MS, H-1 NMR and chiral HPLC analyses, and further chemical derivation followed by the GC-MS analysis. In a field test with. the pheromone synthesized stereoselectively, the male moths were specifically attracted to the (11S,12S)-isomer but not to the antipode. (C) 2001 Elsevier Science Ltd. All rights reserved..
48. N Nakajima, S Hiradate, Y Fujii, Plant growth inhibitory activity of L-canavanine and its mode of action, JOURNAL OF CHEMICAL ECOLOGY, 10.1023/A:1005659714947, Vol.27, No.1, pp.19-31, 2001.01, L-Canavanine is a nonprotein amino acid contained in jack bean [Canavalia ensiformis (L.) DC] and shows a plant inhibitory effect. The inhibitory effect was determined by an immersion test and a microdrop rest that employed rice seedlings. L-Canavanine inhibited elongation of the second leaf sheath of rice seedlings more than other natural bioactive substances, such as salicylic acid and cinnamic acid. The modified microdrop test revealed that the mode of action of L-canavanine had no relation to gibberellin synthesis. In the microdrop test, the inhibitory effect of L-canavanine was decreased by simultaneous addition of L-arginine. an analog of L-canavanine. Free amino acid analysis of rice shoots clearly showed that L-canavanine induced an unusual accumulation of L-arginine. However, accumulation of L-arginine did not cause the inhibitory effect on plant growth. These results suggest that the mechanism of inhibition of L-canavanine is closely related to the inhibition of arginine metabolism..
49. N Nakajima, S Hiradate, Y Fujii, Plant growth inhibitory activity of L-canavanine and its mode of action, JOURNAL OF CHEMICAL ECOLOGY, 10.1023/A:1005659714947, Vol.27, No.1, pp.19-31, 2001.01, L-Canavanine is a nonprotein amino acid contained in jack bean [Canavalia ensiformis (L.) DC] and shows a plant inhibitory effect. The inhibitory effect was determined by an immersion test and a microdrop rest that employed rice seedlings. L-Canavanine inhibited elongation of the second leaf sheath of rice seedlings more than other natural bioactive substances, such as salicylic acid and cinnamic acid. The modified microdrop test revealed that the mode of action of L-canavanine had no relation to gibberellin synthesis. In the microdrop test, the inhibitory effect of L-canavanine was decreased by simultaneous addition of L-arginine. an analog of L-canavanine. Free amino acid analysis of rice shoots clearly showed that L-canavanine induced an unusual accumulation of L-arginine. However, accumulation of L-arginine did not cause the inhibitory effect on plant growth. These results suggest that the mechanism of inhibition of L-canavanine is closely related to the inhibition of arginine metabolism..
50. S Yoshida, S Hiradate, T Tsukamoto, K Hatakeda, A Shirata, Antimicrobial activity of culture filtrate of Bacillus amyloliquefaciens RC-2 isolated from mulberry leaves, PHYTOPATHOLOGY, 10.1094/PHYTO.2001.91.2.181, Vol.91, No.2, pp.181-187, 2001.02, A potential antagonist, Bacillus amyloliquefaciens strain RC-2, against Colletotrichum dermatium, mulberry anthracnose fungus, was obtained from healthy mulberry leaves by in vitro and in vivo screening techniques. Application of culture filtrate of RC-2 inhibited disease on mulberry leaves, indicating that suppression was due to antifungal compounds in the filtrate. Development of mulberry anthracnose on mulberry leaves was inhibited only when the culture filtrate was applied before fungal inoculation, and it was not inhibited by application after inoculation. These results suggest that the antifungal compounds in the filtrate exhibit a preventive effect on the disease. Peptone significantly increased production of the antifungal compounds. The culture filtrate of RC-2 also inhibited the growth of several other phytopathogenic fungi and bacteria, such as Rosellinia necatrix, Pyricularia oryzae, Agrobacterium tumefaciens, and Xanthomonas campestris pv. campestris, in vitro. From the culture filtrate of RC-2, seven kinds of antifungal compounds were isolated by high performance liquid chromatography analysis, and one of the compounds was determined as iturin A2, a cyclic peptide, by nuclear magnetic resonance and fast atom bombardment mass analysis..
51. S Yoshida, S Hiradate, T Tsukamoto, K Hatakeda, A Shirata, Antimicrobial activity of culture filtrate of Bacillus amyloliquefaciens RC-2 isolated from mulberry leaves, PHYTOPATHOLOGY, 10.1094/PHYTO.2001.91.2.181, Vol.91, No.2, pp.181-187, 2001.02, A potential antagonist, Bacillus amyloliquefaciens strain RC-2, against Colletotrichum dermatium, mulberry anthracnose fungus, was obtained from healthy mulberry leaves by in vitro and in vivo screening techniques. Application of culture filtrate of RC-2 inhibited disease on mulberry leaves, indicating that suppression was due to antifungal compounds in the filtrate. Development of mulberry anthracnose on mulberry leaves was inhibited only when the culture filtrate was applied before fungal inoculation, and it was not inhibited by application after inoculation. These results suggest that the antifungal compounds in the filtrate exhibit a preventive effect on the disease. Peptone significantly increased production of the antifungal compounds. The culture filtrate of RC-2 also inhibited the growth of several other phytopathogenic fungi and bacteria, such as Rosellinia necatrix, Pyricularia oryzae, Agrobacterium tumefaciens, and Xanthomonas campestris pv. campestris, in vitro. From the culture filtrate of RC-2, seven kinds of antifungal compounds were isolated by high performance liquid chromatography analysis, and one of the compounds was determined as iturin A2, a cyclic peptide, by nuclear magnetic resonance and fast atom bombardment mass analysis..
52. Screening of Allelopathic activity and identification of "Awa-Akamai" (Traditional red rice) as the most promising cultivar..
53. Effects of plant interaction with natural catechol like chemical substances as L-DOPA.
54. Recent Advances in Soil Acidity and Problems to be Solved : Review and Extraction of the Problenis.
55. Syuntaro Hiradate, Shigenobu Yoshida, Hajime Sugie, Hiroshi Yada, Yoshiharu Fujii, Mulberry anthracnose antagonists (iturins) produced by Bacillus amyloliquefaciens RC-2, Phytochemistry, 10.1016/S0031-9422(02)00365-5, Vol.61, No.6, pp.693-698, 2002.11, Bacillus amyloliquefaciens strain RC-2 produced seven antifungal compounds (1-7) secreted into the culture filtrate. These compounds inhibited the development of mulberry anthracnose caused by the fungus, Colletotrichum dematium. Chemical structural analyses by NMR and FAB-MS revealed that all these compounds were iturins (cyclic peptides with the following sequence: L-Asn → D-Tyr → D-Asn → L-Gln → L-Pro → D-Asn → L-Ser → D-β-amino acid →) and compounds 1-6 are identical to iturins A-2-A-7, respectively. Compound 7 (iturin A-8) is a new iturin, which has a -(CH2)10CH(CH3)CH2CH3 group as a side chain in the β-amino acid in the molecule. © 2002 Elsevier Science Ltd. All rights reserved..
56. First isolation of natural cyanamide, a possible allelochemical from Vicia villosa Roth...
57. Plant growth inhibiting effcts of Cotoneaster salicifolius, Spiraea thunbergii and S. prunifolia.
58. CYANAMIDE AS A POSSIBLE ALLELOCHEMICAL OF HAIRY VETCH
Cyanamide was isolated from hairy vetch (Vicia villosa Roth), a leguminous plant utilized as a cover crop, guided by plant growth inhibitory activity against lettuce seedlings. The crude extract of hairy vetch contained 130 μg of cyanamide per gram fresh weight. A large portion of the inhibitory activity in the crude extract of hairy vetch was explained by the presence of cyanamide, suggesting that the compound is a possible allelochemical of the hairy vetch. We also demonstrated that cyanamide was biosynthesized in hairy vetch seedlings. This is the first report of cyanamide from a natural....
59. CYANAMIDE AS A POSSIBLE ALLELOCHEMICAL OF HAIRY VETCH(Supplement to Abstracts for the XXXVII Annual Meeting of the Japanease Society for Chemical Regulation of Plants).
60. P19 Allelopathic activity of fruiting bodies of higher fungi.
61. P18 Allelopathic substances in red rice, AWA-AKAMAI.
62. T Kamo, S Hiradate, Y Fujii, First isolation of natural cyanamide as a possible allelochemical from hairy vetch Vicia villosa, JOURNAL OF CHEMICAL ECOLOGY, Vol.29, No.2, pp.275-283, 2003.02, Cyanamide was isolated from the leaves and stems of hairy vetch (Vicia villosa), guided by plant growth inhibitory activity against lettuce (Lectuca sativa) seedlings. A large proportion of the inhibitory activity in the crude extract was explained by the presence of cyanamide, suggesting it to be a possible allelochemical in this species. The amount in a 9-day-old seedling, which had been grown without nutrients, reached approx. 40 times that of a nongerminated seed, demonstrating cyanamide biosynthesis in the seedlings. This is the first report on the isolation of a possible allelochemical from hairy vetch and also of the finding of cyanamide as a natural product..
63. T Kamo, S Hiradate, Y Fujii, First isolation of natural cyanamide as a possible allelochemical from hairy vetch Vicia villosa, JOURNAL OF CHEMICAL ECOLOGY, Vol.29, No.2, pp.275-283, 2003.02, Cyanamide was isolated from the leaves and stems of hairy vetch (Vicia villosa), guided by plant growth inhibitory activity against lettuce (Lectuca sativa) seedlings. A large proportion of the inhibitory activity in the crude extract was explained by the presence of cyanamide, suggesting it to be a possible allelochemical in this species. The amount in a 9-day-old seedling, which had been grown without nutrients, reached approx. 40 times that of a nongerminated seed, demonstrating cyanamide biosynthesis in the seedlings. This is the first report on the isolation of a possible allelochemical from hairy vetch and also of the finding of cyanamide as a natural product..
64. 71 Plant growth promoting effect of a mixture of essential oils..
65. 69 Allelopathy of Spiraea thunbergii and S.prunifolia.
66. 66 Method for bioassay to evaluate the allelopathic activity in rhizosphere soil..
67. 63 Distribution of a plant growth inhibitor, cyanamide in leguminous plants and its plant growth inhibitory activity.
68. S Hiradate, Strategies for searching bioactive compounds: Total activity vs. specific activity., ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol.227, p.U28, 2004.03.
69. Syuntaro Hiradate, Speciation of aluminum in soil environments: Application of NMR technique, Soil Science and Plant Nutrition, 10.1080/00380768.2004.10408483, Vol.50, No.3, pp.303-314, 2004.02, Although aluminum (Al) is abundant in soil environments, it is not an essential element and it is toxic to most organisms. Since the toxicity of Al depends on their chemical forms, the importance of Al speciation has been recognized worldwide. Difficulties in Al speciation are caused by the complex coordination chemistry of Al for the hydrolysis and formation of polynuclear species with a variable degree of solubility in aqueous solution. Nondestructive analyses, such as nuclear magnetic resonance (NMR) spectroscopy, could supply primarily im-portant information on the chemical forms of Al and may enable to evaluate the results ob-tained by other methodologies. In the present report, NMR spectral characteristics of environmentally important Al-containing components, such as hydoxyaluminum ions, Alinorganic complexes, Al-organic complexes, and primary and secondary minerals, are summarized for the nuclei of 27Al and 29Si determined by solution NMR and solid-state magic angle spinning (MAS) NMR. Applications of NMR techniques to soil science, including speciation of phytotoxic Al in soil environments and whole soil NMR studies, are described. © 2004 Taylor &
Francis Group, LLC..
70. S Hiradate, Speciation of aluminum in soil environments, SOIL SCIENCE AND PLANT NUTRITION, 10.1080/00380768.2004.10408483, Vol.50, No.3, pp.303-314, 2004.06, Although aluminum (Al) is abundant in soil environments, it is not an essential element and it is toxic to most organisms. Since the toxicity of Al depends on their chemical forms, the importance of Al speciation has been recognized worldwide. Difficulties in Al speciation are caused by the complex coordination chemistry of Al for the hydrolysis and formation of polynuclear species with a variable degree of solubility in aqueous solution. Nondestructive analyses, such as nuclear magnetic resonance (NMR) spectroscopy, could supply primarily im-portant information on the chemical forms of Al and may enable to evaluate the results ob-tained by other methodologies. In the present report, NMR spectral characteristics of environmentally important Al-containing components, such as hydoxyaluminum ions, Al-inorganic complexes, Al-organic complexes, and primary and secondary minerals, are summarized for the nuclei of Al-27 and Si-29 determined by solution NMR and solid-state magic angle spinning (MAS) NMR. Applications of NMR techniques to soil science, including speciation of phytotoxic Al in soil environments and whole soil NMR studies, are described..
71. Z Iqbal, S Hiradate, H Araya, Y Fujii, Plant growth inhibitory activity of Ophiopogon japonicus Ker-Gawler and role of phenolic acids and their analogues: a comparative study, PLANT GROWTH REGULATION, 10.1023/B:GROW.0000045998.68084.4b, Vol.43, No.3, pp.245-250, 2004.07, Allelopathic potential of Ophiopogon japonicus was investigated. The methanolic extract of O. japonicus roots strongly inhibited root and hypocotyls growth of lettuce. Sequential partitioning of the methanol extract with organic solvents showed that the diethyl ether and n-butanol extract possess strong plant growth inhibitory activities. The allelopathic constituents of the diethyl ether extract were isolated and identified as salicylic acid and p-hydroxybenzoic acid by NMR spectroscopy. Both of these phenolic acids were found in the aqueous extracts of leaves as well. The concentration of salicylic acid in roots and leaves were estimated as 0.011 and 0.02%, respectively, and it inhibited the root and shoot of tested plants by 50% even at less than 3 ppm. The p-hydroxybenzoic acid on the other hand was in less abundance (0.005%) and inhibited the plant growth to a lesser extent. The biological activity of commercially available O-methyl derivatives of these phenolic acids was also determined to establish structure-activity relationship. Among these, salicylic acid was found to be the most active one. These results suggest that Ophiopogon japonicus produces plant growth inhibitors, which are responsible for its potential allelopathic activity..
72. Z Iqbal, S Hiradate, H Araya, Y Fujii, Plant growth inhibitory activity of Ophiopogon japonicus Ker-Gawler and role of phenolic acids and their analogues: a comparative study, PLANT GROWTH REGULATION, 10.1023/B:GROW.0000045998.68084.4b, Vol.43, No.3, pp.245-250, 2004.07, Allelopathic potential of Ophiopogon japonicus was investigated. The methanolic extract of O. japonicus roots strongly inhibited root and hypocotyls growth of lettuce. Sequential partitioning of the methanol extract with organic solvents showed that the diethyl ether and n-butanol extract possess strong plant growth inhibitory activities. The allelopathic constituents of the diethyl ether extract were isolated and identified as salicylic acid and p-hydroxybenzoic acid by NMR spectroscopy. Both of these phenolic acids were found in the aqueous extracts of leaves as well. The concentration of salicylic acid in roots and leaves were estimated as 0.011 and 0.02%, respectively, and it inhibited the root and shoot of tested plants by 50% even at less than 3 ppm. The p-hydroxybenzoic acid on the other hand was in less abundance (0.005%) and inhibited the plant growth to a lesser extent. The biological activity of commercially available O-methyl derivatives of these phenolic acids was also determined to establish structure-activity relationship. Among these, salicylic acid was found to be the most active one. These results suggest that Ophiopogon japonicus produces plant growth inhibitors, which are responsible for its potential allelopathic activity..
73. S Hiradate, S Morita, H Sugie, Y Fujii, J Harada, Phytotoxic cis-cinnamoyl glucosides from Spiraea thunbergii, PHYTOCHEMISTRY, 10.1016/j.phytochem.2004.01.010, Vol.65, No.6, pp.731-739, 2004.03, Spiraea thunbergii Sieb. was found to contain 1-O-cis-cinnamoyl-beta-D-glucopyranose and 6-O-(4'-hydroxy-2'-methylene-butyroyl)-1-O-cis-cinnamoyl-beta-D-glucopyranose as major plant growth inhibitory constituents along with related compounds of lower phytotoxicity including 6-O-(trans-cinnamoyl)-1-O-(4"-hydroxy-3"-methyl-furan-2"-one)-beta-D-glucopyranose, 6-O-(4'-hydroxy-2'-methylene-butyroyl)-1-O-trans-cinnamoyl-beta-D-glucopyranose, and 1-O-trans-cinnamoyl-beta-D-glucopyranose. The former three compounds were cinnamoyl glucosides. (C) 2004 Elsevier Ltd. All rights reserved..
74. S Hiradate, S Morita, H Sugie, Y Fujii, J Harada, Phytotoxic cis-cinnamoyl glucosides from Spiraea thunbergii, PHYTOCHEMISTRY, 10.1016/j.phytochem.2004.01.010, Vol.65, No.6, pp.731-739, 2004.03, Spiraea thunbergii Sieb. was found to contain 1-O-cis-cinnamoyl-beta-D-glucopyranose and 6-O-(4'-hydroxy-2'-methylene-butyroyl)-1-O-cis-cinnamoyl-beta-D-glucopyranose as major plant growth inhibitory constituents along with related compounds of lower phytotoxicity including 6-O-(trans-cinnamoyl)-1-O-(4"-hydroxy-3"-methyl-furan-2"-one)-beta-D-glucopyranose, 6-O-(4'-hydroxy-2'-methylene-butyroyl)-1-O-trans-cinnamoyl-beta-D-glucopyranose, and 1-O-trans-cinnamoyl-beta-D-glucopyranose. The former three compounds were cinnamoyl glucosides. (C) 2004 Elsevier Ltd. All rights reserved..
75. P26 Plant growth inhibitory activity of cyanamide in hairy vetch.
76. P25 Allelopathy of fruiting bodies of higher fungi.
77. P24 Allelopathic activity of red rice and investigation of allelochemicals from them.
78. H Nakano, E Nakajima, S Hiradate, Y Fujii, K Yamada, H Shigemori, K Hasegawa, Growth inhibitory alkaloids from mesquite (Prosopis juliflora (Sw.) DC.) leaves, PHYTOCHEMISTRY, 10.1016/j.phytochem.2004.01.006, Vol.65, No.5, pp.587-591, 2004.03, Plant growth inhibitory alkaloids were isolated from the extract of mesquite [Prosopis juliflora (Sw.) DC] leaves. Their chemical structures were established by ESI-MS, H-1 and C-13 NMR spectra analysis. The I-50 value (concentration required for 50% inhibition of control) for root growth of cress (Lepidium sativum L.) seedlings was 400 muM for 3""-oxo-juliprosopine, 500 muM for secojuliprosopinal, and 100 muM for a (1:1) mixture of 3-oxo-juliprosine and 3'-oxo-juliprosine, respectively. On the other hand, the minimum concentration exhibiting inhibitory effect on shoot growth of cress seedlings was 10 muM for 3''"-oxo-juliprosopine, 100 muM for secojuliprosopinal, and 1 muM for a (1:1) mixture of 3-oxo-juliprosine and 3'-oxo-juliprosine, respectively. Among these compounds, a (1:1) mixture of 3-oxo-juliprosine and 3'-oxo-juliprosine exhibited the strongest inhibitory effect on the growth of cress seedlings. (C) 2004 Elsevier Ltd. All rights reserved..
79. H Nakano, E Nakajima, S Hiradate, Y Fujii, K Yamada, H Shigemori, K Hasegawa, Growth inhibitory alkaloids from mesquite (Prosopis juliflora (Sw.) DC.) leaves, PHYTOCHEMISTRY, 10.1016/j.phytochem.2004.01.006, Vol.65, No.5, pp.587-591, 2004.03, Plant growth inhibitory alkaloids were isolated from the extract of mesquite [Prosopis juliflora (Sw.) DC] leaves. Their chemical structures were established by ESI-MS, H-1 and C-13 NMR spectra analysis. The I-50 value (concentration required for 50% inhibition of control) for root growth of cress (Lepidium sativum L.) seedlings was 400 muM for 3""-oxo-juliprosopine, 500 muM for secojuliprosopinal, and 100 muM for a (1:1) mixture of 3-oxo-juliprosine and 3'-oxo-juliprosine, respectively. On the other hand, the minimum concentration exhibiting inhibitory effect on shoot growth of cress seedlings was 10 muM for 3''"-oxo-juliprosopine, 100 muM for secojuliprosopinal, and 1 muM for a (1:1) mixture of 3-oxo-juliprosine and 3'-oxo-juliprosine, respectively. Among these compounds, a (1:1) mixture of 3-oxo-juliprosine and 3'-oxo-juliprosine exhibited the strongest inhibitory effect on the growth of cress seedlings. (C) 2004 Elsevier Ltd. All rights reserved..
80. S Hiradate, N Uchida, Effects of soil organic matter on pH-dependent phosphate sorption by soils, SOIL SCIENCE AND PLANT NUTRITION, Vol.50, No.5, pp.665-675, 2004.10, Effects of soil organic matter (SOM) on P sorption of soils still remain to be clarified because contradictory results have been reported in the literature. In the present study, pH-dependent P sorption on an allophanic Andisol and an alluvial soil was compared with that on hydrogen peroxide (H(2)O(2))-treated, acid-oxalate (OX)-treated, and dithionite-citrate-bicarbonate (DCB)-treated soils. Removal of SOM increased or decreased P sorption depending on the equilibrium pH values and soil types. In the H(2)O(2)-, OX-, and DCB-treated soils, P sorption was pH-dependent, but this trend was not conspicuous in the untreated soils. It is likely that SOM affects P sorption of soils through three factors, competitive sorption, inhibition of polymerization and crystallization of metals such as Al and Fe, and flexible structure of metal-SOM complexes. As a result, the number of available sites for P sorption would remain relatively constant in the wide range of equilibrium pH values in the presence of SOM. The P sorption characteristics were analyzed at constant equilibrium pH values (4.0 to 7.0) using the Langmuir equation as a local isotherm. The maximum number of available sites for P sorption (Q(max)) was pH-dependent in the H(2)O(2)-, OX-, and DCB-treated soils, while this trend was not conspicuous in the untreated soils. Affinity constants related to binding strength (K) were less affected by the equilibrium pH values, soil types, and soil treatments, and were almost constant (log K approximate to 4.5). These findings support the hypothesis that SOM plays a role in keeping the number of available sites for P sorption relatively constant but does not affect the P sorption affinity. By estimating the Q(max) and K values as a function of equilibrium pH values, pH-dependent P sorption was well simulated with four or two adjustable parameters. This empirical model could be useful and convenient for a rough estimation of the pH-dependent P sorption of soils..
81. S Hiradate, N Uchida, Effects of soil organic matter on pH-dependent phosphate sorption by soils, SOIL SCIENCE AND PLANT NUTRITION, Vol.50, No.5, pp.665-675, 2004.10, Effects of soil organic matter (SOM) on P sorption of soils still remain to be clarified because contradictory results have been reported in the literature. In the present study, pH-dependent P sorption on an allophanic Andisol and an alluvial soil was compared with that on hydrogen peroxide (H(2)O(2))-treated, acid-oxalate (OX)-treated, and dithionite-citrate-bicarbonate (DCB)-treated soils. Removal of SOM increased or decreased P sorption depending on the equilibrium pH values and soil types. In the H(2)O(2)-, OX-, and DCB-treated soils, P sorption was pH-dependent, but this trend was not conspicuous in the untreated soils. It is likely that SOM affects P sorption of soils through three factors, competitive sorption, inhibition of polymerization and crystallization of metals such as Al and Fe, and flexible structure of metal-SOM complexes. As a result, the number of available sites for P sorption would remain relatively constant in the wide range of equilibrium pH values in the presence of SOM. The P sorption characteristics were analyzed at constant equilibrium pH values (4.0 to 7.0) using the Langmuir equation as a local isotherm. The maximum number of available sites for P sorption (Q(max)) was pH-dependent in the H(2)O(2)-, OX-, and DCB-treated soils, while this trend was not conspicuous in the untreated soils. Affinity constants related to binding strength (K) were less affected by the equilibrium pH values, soil types, and soil treatments, and were almost constant (log K approximate to 4.5). These findings support the hypothesis that SOM plays a role in keeping the number of available sites for P sorption relatively constant but does not affect the P sorption affinity. By estimating the Q(max) and K values as a function of equilibrium pH values, pH-dependent P sorption was well simulated with four or two adjustable parameters. This empirical model could be useful and convenient for a rough estimation of the pH-dependent P sorption of soils..
82. N Yamaguchi, S Hiradate, M Mizoguchi, T Miyazaki, Disappearance of aluminum tridecamer from hydroxyaluminum solution in the presence of humic acid, SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, Vol.68, No.6, pp.1838-1843, 2004.11, We investigated the influences of humic acid on the removal of Al tridecamer (Al-13) from a hydroxyaluminum (HyA) solution at various humic acid/Al ratios. The Al species contained in the solution were analyzed by using a liquid-state Al-27-NMR and an atomic absorption spectrometer and fractionated into three Al species: (i) Al-13, (ii) Al monomer and dimer (Al-SYM), and (iii) other undefined species including aggregated/precipitated Al (Al-NON). By the addition of humic acid to the HyA solution, the concentration of Al-13 was rapidly decreased within 0.007 d (10 min). The decrease in Al-13 and the increase in Al-NON were more pronounced at a higher humic acid/Al ratio. When the molar ratio of humic acid carboxylic groups to Al exceeded 0.8, Al-13 Was undetected from solution within 0.007 d. The formation of Al-13-humic acid complexes and the aggregation/precipitation of those complexes were a predominant mechanism in removing aqueous Al-13 at the early stage of the reaction. Approximately 10 mol of carboxylic groups in humic acid were required to remove 1 mol of Al13B from the HyA solution. Aqueous Al-13 had greater preference in precipitating with humic acid than Al-SYM. After 5 to 570 d of aging, the concentration of Al-13 and Al-NON also decreased and increased, respectively, both in the presence and absence of humic acid. In conclusion, aqueous Al-13 would not exist in soil solution under a high humic acid condition..
83. N Yamaguchi, S Hiradate, M Mizoguchi, T Miyazaki, Disappearance of aluminum tridecamer from hydroxyaluminum solution in the presence of humic acid, SOIL SCIENCE SOCIETY OF AMERICA JOURNAL, Vol.68, No.6, pp.1838-1843, 2004.11, We investigated the influences of humic acid on the removal of Al tridecamer (Al-13) from a hydroxyaluminum (HyA) solution at various humic acid/Al ratios. The Al species contained in the solution were analyzed by using a liquid-state Al-27-NMR and an atomic absorption spectrometer and fractionated into three Al species: (i) Al-13, (ii) Al monomer and dimer (Al-SYM), and (iii) other undefined species including aggregated/precipitated Al (Al-NON). By the addition of humic acid to the HyA solution, the concentration of Al-13 was rapidly decreased within 0.007 d (10 min). The decrease in Al-13 and the increase in Al-NON were more pronounced at a higher humic acid/Al ratio. When the molar ratio of humic acid carboxylic groups to Al exceeded 0.8, Al-13 Was undetected from solution within 0.007 d. The formation of Al-13-humic acid complexes and the aggregation/precipitation of those complexes were a predominant mechanism in removing aqueous Al-13 at the early stage of the reaction. Approximately 10 mol of carboxylic groups in humic acid were required to remove 1 mol of Al13B from the HyA solution. Aqueous Al-13 had greater preference in precipitating with humic acid than Al-SYM. After 5 to 570 d of aging, the concentration of Al-13 and Al-NON also decreased and increased, respectively, both in the presence and absence of humic acid. In conclusion, aqueous Al-13 would not exist in soil solution under a high humic acid condition..
84. S Hiradate, T Nakadai, H Shindo, T Yoneyama, Carbon source of humic substances in some Japanese volcanic ash soils determined by carbon stable isotopic ratio, delta C-13, GEODERMA, 10.1016/S0016-7061(03)00257-X, Vol.119, No.1-2, pp.133-141, 2004.03, Volcanic ash soils (including Andisols) have been known to accumulate extremely large amounts of humic acids in their thick surface horizons, and their accumulation mechanism is of interest. Two mechanisms have been proposed: (1) active metals like Al and Fe, supplied from weathered volcanic materials, stabilize humic acids through complexation reactions; (2) cultivated Japanese pampas grasses (Miscanthus sinensis A.) and its charred materials are the major carbon source of humic acids. In the present study, contribution ratio of the pampas grass (C4-plant) on the carbons of the humic acids was determined by measuring their stable isotopic ratio of carbon (delta(13)C). In Japanese volcanic ash soils, humic acids were originated from both C3- and C4-plants, and the contribution ratio of C4-plants (mostly pampas grass) ranged from 18% to 52%. Highly humified (dark-colored) humic acids tended to show higher contribution ratio of C4-plants among volcanic ash soils, although the major part of the carbon had originated from C3-plants. It was also clarified that the delta(13)C values of crude soil samples correlated well with those of humic and fulvic acids. Therefore, reported delta(13)C values of crude soil samples in the literature would be useful for estimating the carbon source of soil humic substances. Literature survey of the delta(13)C values of crude soil samples also indicated that a large part of the carbon in humic substances has originated from C3-plants rather than C4-plants, implying the importance of the active metals (such as Al and Fe) on the formation and accumulation of the humic acids in volcanic ash soils. (C) 2003 Elsevier B.V. All rights reserved..
85. 61. Incorporation of Labeled Nitrate into Cyanamide in Hairy Vetch Vicia villosa
Cyanamide (NH_2CN) has been industrially produced in large quantities for a long time. We have isolated cyanamide as a plant growth inhibitor from hairy vetch Vicia villosa. Although we excluded the possibility that the cyanamide isolated was an unexpectedly contaminating agrochemical, the details of its biosynthesis remain unknown because this compound has never been considered as a natural product. In this report we demonstrate the de novo production of cyanamide in this legume using a ^<15>N-labeled nitrogen source. The extracts of the seedlings of V. villosa grown with and without (^<15....
86. H Shindo, M Yoshida, A Yamamoto, H Honma, S Hiradate, delta(13)C values of organic constituents and possible source of humic substances in Japanese volcanic ash soils, SOIL SCIENCE, Vol.170, No.3, pp.175-182, 2005.03, To gain a better understanding about the delta(13)C values of organic constituents and possible source of humic substances in Japanese volcanic ash soils, we determined the delta(13)C values of charred plant fragments, humic and fulvic acids, and whole soils, using 10 volcanic ash soil samples. Furthermore, the characteristics of the humic acid obtained from the dil. H(2)O(2)-treated residues of charred plant materials, which were produced during the burning of a grassland, were compared with those of black (type A) humic acids in volcanic ash soils. The delta(13)C values of the charred plant fragments, humic and fulvic acids, and whole soils studied ranged from -25 to -17 parts per thousand, -25 to -17 parts per thousand, -23 to -15 parts per thousand, and -24 to -17 parts per thousand, respectively. The delta(13)C values of the whole soils were highly correlated with those of the charred plant fragments (r = 0.968, significant at 0.1% level), humic acids (r = 0.947, significant at 0.1% level) or fulvic acids (r = 0.900, significant at 0.1% level), suggesting that in Japanese volcanic ash soils, the delta(13)C data of whole soils are valuable for discussing and estimating the origin of carbon of charred plant fragments as well as humic and fulvic acids. The delta(13)C values of the charred plant fragments were highly correlated with those of the fulvic acids (r = 0.792, significant at 1% level) and especially humic acids (P = 0.951, significant at 0.1% level). The contribution ratios of C4-plant-derived carbon on the carbon in the charred plant fragments, humic and fulvic acids, and whole soils ranged from 15 to 69%, 16 to 65%, 29 to 86%, and 24 to 66%, respectively. The (13)C-NMR spectrum and X-ray diffraction pattern of the humic acid obtained from the oxidative degradation products of the charred plant materials were similar to those of type A humic acids reported previously. Based on these findings, it was assumed that both charred C3- and C4-plant materials merit close attention as an important source of humic substances in Japanese volcanic ash soils..
87. H Shindo, M Yoshida, A Yamamoto, H Honma, S Hiradate, delta(13)C values of organic constituents and possible source of humic substances in Japanese volcanic ash soils, SOIL SCIENCE, Vol.170, No.3, pp.175-182, 2005.03, To gain a better understanding about the delta(13)C values of organic constituents and possible source of humic substances in Japanese volcanic ash soils, we determined the delta(13)C values of charred plant fragments, humic and fulvic acids, and whole soils, using 10 volcanic ash soil samples. Furthermore, the characteristics of the humic acid obtained from the dil. H(2)O(2)-treated residues of charred plant materials, which were produced during the burning of a grassland, were compared with those of black (type A) humic acids in volcanic ash soils. The delta(13)C values of the charred plant fragments, humic and fulvic acids, and whole soils studied ranged from -25 to -17 parts per thousand, -25 to -17 parts per thousand, -23 to -15 parts per thousand, and -24 to -17 parts per thousand, respectively. The delta(13)C values of the whole soils were highly correlated with those of the charred plant fragments (r = 0.968, significant at 0.1% level), humic acids (r = 0.947, significant at 0.1% level) or fulvic acids (r = 0.900, significant at 0.1% level), suggesting that in Japanese volcanic ash soils, the delta(13)C data of whole soils are valuable for discussing and estimating the origin of carbon of charred plant fragments as well as humic and fulvic acids. The delta(13)C values of the charred plant fragments were highly correlated with those of the fulvic acids (r = 0.792, significant at 1% level) and especially humic acids (P = 0.951, significant at 0.1% level). The contribution ratios of C4-plant-derived carbon on the carbon in the charred plant fragments, humic and fulvic acids, and whole soils ranged from 15 to 69%, 16 to 65%, 29 to 86%, and 24 to 66%, respectively. The (13)C-NMR spectrum and X-ray diffraction pattern of the humic acid obtained from the oxidative degradation products of the charred plant materials were similar to those of type A humic acids reported previously. Based on these findings, it was assumed that both charred C3- and C4-plant materials merit close attention as an important source of humic substances in Japanese volcanic ash soils..
88. S Morita, S Hiradate, Y Fujii, J Harada, cis-cinnamoyl glucoside as a major plant growth inhibitor contained in Spiraea prunifolia, PLANT GROWTH REGULATION, 10.1007/s10725-005-8086-2, Vol.46, No.2, pp.125-131, 2005.06, Crude extracts of the leaves of Spiraea prunifolia Sieb. showed high plant-growth-inhibiting activity comparable to that of S. thunbergii extracts. To isolate the causal compound in S. prunifolia, we performed bioassay-directed purification by monitoring the biological activity per unit weight of the organism containing the bioactive compound ( total activity). We isolated 1-O-cis-cinnamoyl-beta-D-glucopyranose (cis-CG) and identified it as the most important growth-inhibiting constituent in the crude extracts. We did not detect 6-O-(4'-hydroxy-2'-methylenebutyroyl)-1-O-cis-cinnamoyl-beta-D-glucopyranose (cis-BCG) in S. prunifolia, though it is a major plant growth inhibitor in S. thunbergii together with cis-CG. We estimated the cis-CG content in S. prunifolia to be 3.84 mmol kg(-1) F. W. This amount is comparable to the cis-CG plus cis-BCG content in S. thunbergii (3.59 mmol kg(-1) F. W.). This indicates that S. prunifolia and S. thunbergii have equally high potential to inhibit plant growth, and cis-CG acts as the most important plant-growth inhibitor in S. prunifolia extracts..
89. S Morita, S Hiradate, Y Fujii, J Harada, cis-cinnamoyl glucoside as a major plant growth inhibitor contained in Spiraea prunifolia, PLANT GROWTH REGULATION, 10.1007/s10725-005-8086-2, Vol.46, No.2, pp.125-131, 2005.06, Crude extracts of the leaves of Spiraea prunifolia Sieb. showed high plant-growth-inhibiting activity comparable to that of S. thunbergii extracts. To isolate the causal compound in S. prunifolia, we performed bioassay-directed purification by monitoring the biological activity per unit weight of the organism containing the bioactive compound ( total activity). We isolated 1-O-cis-cinnamoyl-beta-D-glucopyranose (cis-CG) and identified it as the most important growth-inhibiting constituent in the crude extracts. We did not detect 6-O-(4'-hydroxy-2'-methylenebutyroyl)-1-O-cis-cinnamoyl-beta-D-glucopyranose (cis-BCG) in S. prunifolia, though it is a major plant growth inhibitor in S. thunbergii together with cis-CG. We estimated the cis-CG content in S. prunifolia to be 3.84 mmol kg(-1) F. W. This amount is comparable to the cis-CG plus cis-BCG content in S. thunbergii (3.59 mmol kg(-1) F. W.). This indicates that S. prunifolia and S. thunbergii have equally high potential to inhibit plant growth, and cis-CG acts as the most important plant-growth inhibitor in S. prunifolia extracts..
90. S Hiradate, SI Wada, Weathering process of volcanic glass to allophane determined by Al-27 and Si-29 solid-state NMR, CLAYS AND CLAY MINERALS, 10.1346/CCMN.2005.0530408, Vol.53, No.4, pp.401-408, 2005.08, To clarify the weathering process of volcanic glass to allophane, solid-state Si-29 and Al-27 magic angle spinning (MAS) nuclear magnetic resonance (NMR) signals of four Japanese volcanic glasses and two (Al- and Si-rich) allophanes were assigned. The volcanic glasses showed a broad 29 Si NMR signal between -80 and -120 ppm with the peak centered at similar to-104 ppm, indicating that they were rich in Si-O-Si bridging structure (silica gel-like polymer Si). Aluminum was present in tetrahedral form in the four volcanic glass samples. In both Al- and Si-rich allophanes, octahedral Al (3 ppm b y 27 Al NMR) and imogolite-like Si (Q(3)3(VI)Al, -78 ppm b y Si-29 NMR) were the major components. In a Si-rich allophane, NMR signals centered at around -85 ppm for 29Si and 55 ppm for 27 Al were also observed, although it is possible that those signals were derived from impurities. Impurities could have originated from the soils and/or been unexpectedly synthesized during the purification procedures, e.g. during hot 2% Na2CO3 treatments. Based on the NMR spectra of size-fractionated soil samples, the weathering process of volcanic glass to allophane was proposed as follows: (1) dissolution of Al from volcanic glass accompanied by the transformation of Al-IV to Al-VI; (2) formation of a gibbsite-like sheet resulting from the hydrolysis of the dissolved Al; (3) dissolution of silica gel-like polymer Si in volcanic glass resulting in the formation of monosilicic acid; and (4) formation of Si(OH)((OAl)-Al-VI)(3) structure (Q(3)3(VI)Al) as a result of the reaction between the gibbsite-like sheet and the monosilicic acid. These formation reactions of allophane could occur in solution as well as on the surface of volcanic glass..
91. S Hiradate, SI Wada, Weathering process of volcanic glass to allophane determined by Al-27 and Si-29 solid-state NMR, CLAYS AND CLAY MINERALS, 10.1346/CCMN.2005.0530408, Vol.53, No.4, pp.401-408, 2005.08, To clarify the weathering process of volcanic glass to allophane, solid-state Si-29 and Al-27 magic angle spinning (MAS) nuclear magnetic resonance (NMR) signals of four Japanese volcanic glasses and two (Al- and Si-rich) allophanes were assigned. The volcanic glasses showed a broad 29 Si NMR signal between -80 and -120 ppm with the peak centered at similar to-104 ppm, indicating that they were rich in Si-O-Si bridging structure (silica gel-like polymer Si). Aluminum was present in tetrahedral form in the four volcanic glass samples. In both Al- and Si-rich allophanes, octahedral Al (3 ppm b y 27 Al NMR) and imogolite-like Si (Q(3)3(VI)Al, -78 ppm b y Si-29 NMR) were the major components. In a Si-rich allophane, NMR signals centered at around -85 ppm for 29Si and 55 ppm for 27 Al were also observed, although it is possible that those signals were derived from impurities. Impurities could have originated from the soils and/or been unexpectedly synthesized during the purification procedures, e.g. during hot 2% Na2CO3 treatments. Based on the NMR spectra of size-fractionated soil samples, the weathering process of volcanic glass to allophane was proposed as follows: (1) dissolution of Al from volcanic glass accompanied by the transformation of Al-IV to Al-VI; (2) formation of a gibbsite-like sheet resulting from the hydrolysis of the dissolved Al; (3) dissolution of silica gel-like polymer Si in volcanic glass resulting in the formation of monosilicic acid; and (4) formation of Si(OH)((OAl)-Al-VI)(3) structure (Q(3)3(VI)Al) as a result of the reaction between the gibbsite-like sheet and the monosilicic acid. These formation reactions of allophane could occur in solution as well as on the surface of volcanic glass..
92. S Wakamura, N Arakaki, M Yamamoto, S Hiradate, H Yasui, K Kinjo, T Yasuda, H Yamazawa, T Ando, Sex pheromone and related compounds in the ishigaki and okinawa strains of the tussock moth Orgyia postica (Walker) (Lepidoptera : Lymantriidae), BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 10.1271/bbb.69.957, Vol.69, No.5, pp.957-965, 2005.05, Two distinct electroantennographycally active (EAG-active) components, A and B, and a weakly active component C were found in a solvent extract from virgin females of the Ishigaki strain of the tussock moth, Orgyia postica (Walker). Components A, 13, and C were found in the extract of the females at 4.0, 0.5, and 4.0 ng/female respectively. Components A, B, and C were identified as (6Z,9Z,11S,12S)-11,12-epoxyhenicosa-6,9-diene [(11S,12S)-1: posticlure], (6Z)-henicos-6-en-11-one (2), and (6Z,9Z)-henicosa-6,9-diene (3), respectively. Component B was absent in the extract from the Okinawa strain, in which components A and C were present at 2.0 and 1.5 ng/female respectively. (11S,12S)-1 and the racemic mixture showed attractiveness for both the Okinawa and Ishigaki strains, whereas (11R,12R)-1 did not. The addition of 2 significantly reduced the trap catches with (11S,12S)-1 on the Okinawa strain which lacked 2, while there was no significant inhibitory effect on the Ishigaki strain. The addition of 3 to (11S,12S)-1 did not significantly affect trap catches at Ishigaki or Okinawa. This confirmed that the attractant pheromone of O. postica of the Ishigaki strain is also (11S,12S)-1..
93. S Wakamura, N Arakaki, M Yamamoto, S Hiradate, H Yasui, K Kinjo, T Yasuda, H Yamazawa, T Ando, Sex pheromone and related compounds in the ishigaki and okinawa strains of the tussock moth Orgyia postica (Walker) (Lepidoptera : Lymantriidae), BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 10.1271/bbb.69.957, Vol.69, No.5, pp.957-965, 2005.05, Two distinct electroantennographycally active (EAG-active) components, A and B, and a weakly active component C were found in a solvent extract from virgin females of the Ishigaki strain of the tussock moth, Orgyia postica (Walker). Components A, 13, and C were found in the extract of the females at 4.0, 0.5, and 4.0 ng/female respectively. Components A, B, and C were identified as (6Z,9Z,11S,12S)-11,12-epoxyhenicosa-6,9-diene [(11S,12S)-1: posticlure], (6Z)-henicos-6-en-11-one (2), and (6Z,9Z)-henicosa-6,9-diene (3), respectively. Component B was absent in the extract from the Okinawa strain, in which components A and C were present at 2.0 and 1.5 ng/female respectively. (11S,12S)-1 and the racemic mixture showed attractiveness for both the Okinawa and Ishigaki strains, whereas (11R,12R)-1 did not. The addition of 2 significantly reduced the trap catches with (11S,12S)-1 on the Okinawa strain which lacked 2, while there was no significant inhibitory effect on the Ishigaki strain. The addition of 3 to (11S,12S)-1 did not significantly affect trap catches at Ishigaki or Okinawa. This confirmed that the attractant pheromone of O. postica of the Ishigaki strain is also (11S,12S)-1..
94. S Hiradate, S Morita, A Furubayashi, Y Fujii, J Harada, Plant growth inhibition by cis-cinnamoyl glucosides and cis-cinnamic acid, JOURNAL OF CHEMICAL ECOLOGY, 10.1007/s10886-005-2047-0, Vol.31, No.3, pp.591-601, 2005.03, Spiraea thunbergii Sieb. contains 1-O-cis-cinnamoyl-O-D-glucopyranose (CG) and 6-O-(4'-hydroxy-2'-methylene-butyroyl)-1-O-cis-cinnamoyl-beta-D-glucopyranose (BCG) as major plant growth inhibiting constituents. In the present study, we determined the inhibitory activity of CG and BCG on root elongation of germinated seedlings of lettuce (Lactuca sativa), pigweed (Amaranthus retroflexus), red clover (Trifolium pratense), timothy (Phleum pratense), and bok choy (Brassica rapa var chinensis) in comparison with that of two well-known growth inhibitors, 2,4-dichlorophenoxyacetic acid (2,4-D) and (+)2-cis-4-trans-abscisic acid (cis-ABA), as well as two related chemicals of CG and BCG, cis-cinnamic acid (cis-CA) and trans-cinnamic acid (trans-CA). The EC50 values for CG and BCG on lettuce were roughly one-half to one-quarter of the value for cis-ABA. cis-Cinnamic acid, which is a component of CG and BCG, possessed almost the same inhibitory activity of CG and BCG, suggesting that the essential chemical structure responsible for the inhibitory activity of CG and BCG is cis-CA. The cis-stereochemistry of the methylene moiety is apparently needed for high inhibitory activity, as trans-CA had an EC50 value roughly 100 times that of CG, BCG, and cis-CA. Growth inhibition by CG, BCG, and cis-CA was influenced by the nature of the soil in the growing medium: alluvial soil preserved the bioactivity, whereas volcanic ash and calcareous soils inhibited bioactivity. These findings indicate a potential role of cis-CA and its glucosides as allelochemicals for use as plant growth regulators in agricultural fields..
95. S Hiradate, S Morita, A Furubayashi, Y Fujii, J Harada, Plant growth inhibition by cis-cinnamoyl glucosides and cis-cinnamic acid, JOURNAL OF CHEMICAL ECOLOGY, 10.1007/s10886-005-2047-0, Vol.31, No.3, pp.591-601, 2005.03, Spiraea thunbergii Sieb. contains 1-O-cis-cinnamoyl-O-D-glucopyranose (CG) and 6-O-(4'-hydroxy-2'-methylene-butyroyl)-1-O-cis-cinnamoyl-beta-D-glucopyranose (BCG) as major plant growth inhibiting constituents. In the present study, we determined the inhibitory activity of CG and BCG on root elongation of germinated seedlings of lettuce (Lactuca sativa), pigweed (Amaranthus retroflexus), red clover (Trifolium pratense), timothy (Phleum pratense), and bok choy (Brassica rapa var chinensis) in comparison with that of two well-known growth inhibitors, 2,4-dichlorophenoxyacetic acid (2,4-D) and (+)2-cis-4-trans-abscisic acid (cis-ABA), as well as two related chemicals of CG and BCG, cis-cinnamic acid (cis-CA) and trans-cinnamic acid (trans-CA). The EC50 values for CG and BCG on lettuce were roughly one-half to one-quarter of the value for cis-ABA. cis-Cinnamic acid, which is a component of CG and BCG, possessed almost the same inhibitory activity of CG and BCG, suggesting that the essential chemical structure responsible for the inhibitory activity of CG and BCG is cis-CA. The cis-stereochemistry of the methylene moiety is apparently needed for high inhibitory activity, as trans-CA had an EC50 value roughly 100 times that of CG, BCG, and cis-CA. Growth inhibition by CG, BCG, and cis-CA was influenced by the nature of the soil in the growing medium: alluvial soil preserved the bioactivity, whereas volcanic ash and calcareous soils inhibited bioactivity. These findings indicate a potential role of cis-CA and its glucosides as allelochemicals for use as plant growth regulators in agricultural fields..
96. PA-09 Community structure of bacteria inhabiting wheat heads and their production of quorum sensing-related signal molecules(AGRICULTURAL SOIL ECOSYSTEM,Session A,(1) Poster presentations).
97. E Nakajima, Z Iqbal, H Araya, S Hiradate, M Hamano, Y Fujii, Isolation and identification of a plant growth promotive substance from mixture of essential plant oils, PLANT GROWTH REGULATION, 10.1007/s10725-004-7087-x, Vol.45, No.1, pp.47-51, 2005.01, The PCS (commercial products by Field Science Co, Japan, used for air fresheners) was analyzed for the presence of bioactive constituents and their role as root growth promoters. Chromatographic separation of the methanolic solution of PCS resulted in the isolation of an promoting active substance, which was identified using GC-mass spectrometry and NMR spectroscopy as 1,2-propanediol (CH(3)CH(OH)CH(2)OH). Lettuce seedling growth bioassay as test plant revealed that 1,2-propanediol can act as potent root growth promoter; enhancing the growth of lettuce seedling radicle at a concentration 0.01 ppm. The concentration of 1,2-propanediol in PCS mixture was estimated as 4 g/l. These studies suggest that 1,2-propanediol might play an important role in the plant growth promoting activity of PCS..
98. E Nakajima, Z Iqbal, H Araya, S Hiradate, M Hamano, Y Fujii, Isolation and identification of a plant growth promotive substance from mixture of essential plant oils, PLANT GROWTH REGULATION, 10.1007/s10725-004-7087-x, Vol.45, No.1, pp.47-51, 2005.01, The PCS (commercial products by Field Science Co, Japan, used for air fresheners) was analyzed for the presence of bioactive constituents and their role as root growth promoters. Chromatographic separation of the methanolic solution of PCS resulted in the isolation of an promoting active substance, which was identified using GC-mass spectrometry and NMR spectroscopy as 1,2-propanediol (CH(3)CH(OH)CH(2)OH). Lettuce seedling growth bioassay as test plant revealed that 1,2-propanediol can act as potent root growth promoter; enhancing the growth of lettuce seedling radicle at a concentration 0.01 ppm. The concentration of 1,2-propanediol in PCS mixture was estimated as 4 g/l. These studies suggest that 1,2-propanediol might play an important role in the plant growth promoting activity of PCS..
99. Syuntaro Hiradate, Tsunashi Kamo, Eri Nakajima, Kenji Kato, Yoshiharu Fujii, Direct quantitative determination of cyanamide by stable isotope dilution gas chromatography–mass spectrometry, Journal of Chromatography A, 10.1016/j.chroma.2005.08.035, Vol.1098, No.1-2, pp.138-143, 2005.12.
100. S Hiradate, A Furubayashi, Y Fujii, Changes in chemical structure and biological activity of L-DOPA as influenced by an Andosol and its components, SOIL SCIENCE AND PLANT NUTRITION, 10.1111/j.1747-0765.2005.tb00055.x, Vol.51, No.4, pp.477-484, 2005.08, Velvetbean (Mucuna pruriens) has been reported to release 3-(3',4'-dihydroxyphenyl)-L-alanine (L-DOPA) as an allelochemical that inhibits the growth of other plants, although the inhibitory activity depends on the soil type and it is extremely reduced in Andosols. To clarify the effects of Andosols and their components on the chemical structure and plant-growth-inhibitory activity of L-DOPA, an L-DOPA solution was reacted with an Andosol and its components (weathered pumice and purified allophane), and the resultant solution was subjected to H-1 nuclear magnetic resonance and ultraviolet-visible spectral analyses, and plant-growth-inhibitory activity tests. When the L-DOPA solution was added to the soil components, the concentration Of L-DOPA in the solution decreased by adsorption and transformation (polymerization) reactions. The adsorption mechanism included a ligand exchange reaction. The rate of L-DOPA transformation was faster at higher pH values. The soil components displayed a catalytic activity and accelerated the transformation of L-DOPA. Similar transformation occurred when light was irradiated. At pH values higher than 4.0, the transformed products from L-DOPA consisted of humic substances-like heterogeneous components, whereas specific components with low molecular weight were included when L-DOPA was transformed at a pH value of 9.7 or higher. The plant-growth-inhibitory activity Of L-DOPA was extremely weakened when L-DOPA was adsorbed on or transformed (polymerized) by soil components. Therefore, in soils with high abilities of adsorption and transformation of L-DOPA such as in Andosols, it was likely that the L-DOPA concentration in the soil solution decreased quickly by adsorption and transformation reactions and the allelopathic activity of L-DOPA was lost..
101. S Hiradate, A Furubayashi, Y Fujii, Changes in chemical structure and biological activity of L-DOPA as influenced by an Andosol and its components, SOIL SCIENCE AND PLANT NUTRITION, 10.1111/j.1747-0765.2005.tb00055.x, Vol.51, No.4, pp.477-484, 2005.08, Velvetbean (Mucuna pruriens) has been reported to release 3-(3',4'-dihydroxyphenyl)-L-alanine (L-DOPA) as an allelochemical that inhibits the growth of other plants, although the inhibitory activity depends on the soil type and it is extremely reduced in Andosols. To clarify the effects of Andosols and their components on the chemical structure and plant-growth-inhibitory activity of L-DOPA, an L-DOPA solution was reacted with an Andosol and its components (weathered pumice and purified allophane), and the resultant solution was subjected to H-1 nuclear magnetic resonance and ultraviolet-visible spectral analyses, and plant-growth-inhibitory activity tests. When the L-DOPA solution was added to the soil components, the concentration Of L-DOPA in the solution decreased by adsorption and transformation (polymerization) reactions. The adsorption mechanism included a ligand exchange reaction. The rate of L-DOPA transformation was faster at higher pH values. The soil components displayed a catalytic activity and accelerated the transformation of L-DOPA. Similar transformation occurred when light was irradiated. At pH values higher than 4.0, the transformed products from L-DOPA consisted of humic substances-like heterogeneous components, whereas specific components with low molecular weight were included when L-DOPA was transformed at a pH value of 9.7 or higher. The plant-growth-inhibitory activity Of L-DOPA was extremely weakened when L-DOPA was adsorbed on or transformed (polymerized) by soil components. Therefore, in soils with high abilities of adsorption and transformation of L-DOPA such as in Andosols, it was likely that the L-DOPA concentration in the soil solution decreased quickly by adsorption and transformation reactions and the allelopathic activity of L-DOPA was lost..
102. H Nasir, Z Iqbal, S Hiradate, Y Fujii, Allelopathic potential of Robinia pseudo-acacia L., JOURNAL OF CHEMICAL ECOLOGY, 10.1007/s10886-005-6084-5, Vol.31, No.9, pp.2179-2192, 2005.09, Robinia pseudo-acacia L. (black locust) is a nonindigenous species currently invading the central part of Japanese grasslands. Several allelochemicals were identified and characterized from the leaf tissue. The growth of both radicle and hypocotyl in the tested species (barnyard grass, white clover, lettuce, and Chinese cabbage) was reduced when grown in soil mixed with the leaves of R. pseudo-acacia at various concentrations. Aqueous leaf extracts, when bioassayed, exhibited a significant suppression of radicle growth. Chromatographic separation of an ethanolic extract of R. pseudo-acacia leaves resulted in isolation of three compounds, identified as robinetin (1), myricetin (2), and quercetin (3) by nuclear magnetic resonance and mass spectroscopy. All inhibited root and shoot growth of lettuce. Robinetin, found in a large amount, caused 50% suppression of the root and shoot growth of lettuce at 100 ppm. The presence of these bioactive substances in leaf tissue suggests a potential role for flavonoids in R. pseudo-acacia invasion in introduced habitats..
103. H Nasir, Z Iqbal, S Hiradate, Y Fujii, Allelopathic potential of Robinia pseudo-acacia L., JOURNAL OF CHEMICAL ECOLOGY, 10.1007/s10886-005-6084-5, Vol.31, No.9, pp.2179-2192, 2005.09, Robinia pseudo-acacia L. (black locust) is a nonindigenous species currently invading the central part of Japanese grasslands. Several allelochemicals were identified and characterized from the leaf tissue. The growth of both radicle and hypocotyl in the tested species (barnyard grass, white clover, lettuce, and Chinese cabbage) was reduced when grown in soil mixed with the leaves of R. pseudo-acacia at various concentrations. Aqueous leaf extracts, when bioassayed, exhibited a significant suppression of radicle growth. Chromatographic separation of an ethanolic extract of R. pseudo-acacia leaves resulted in isolation of three compounds, identified as robinetin (1), myricetin (2), and quercetin (3) by nuclear magnetic resonance and mass spectroscopy. All inhibited root and shoot growth of lettuce. Robinetin, found in a large amount, caused 50% suppression of the root and shoot growth of lettuce at 100 ppm. The presence of these bioactive substances in leaf tissue suggests a potential role for flavonoids in R. pseudo-acacia invasion in introduced habitats..
104. A Furubayashi, S Hiradate, Y Fujii, Adsorption and transformation reactions of L-DOPA in soils, SOIL SCIENCE AND PLANT NUTRITION, 10.1111/j.1747-0765.2005.tb00116.x, Vol.51, No.6, pp.819-825, 2005.10, 3-(3',4'-Dihydroxyphenyl)-L-alanine (L-DOPA), which is a component of velvetbean (Mucuna pruriens), displays a high inhibitory activity to plant growth. The inhibitory activity is influenced by the presence of soils, because L-DOPA is eliminated in soils. In the present study, the effect of several soil types (volcanic ash, calcareous, and alluvial soils) on the L-DOPA disappearance was investigated at constant equilibrium pH values. In the presence of soils, L-DOPA disappeared with the reaction time, and the disappearance was associated with three reactions: adsorption reaction (characterized by fast and sudden disappearance of L-DOPA within the initial 8 h period), catalytic transformation reaction (constant L-DOPA disappearance throughout the reaction period), and biotransformation caused by microbial activity (accelerated L-DOPA disappearance observed after 72 h of reaction time). The adsorption and transformation reactions consisted of physicochemical reactions mediated by the presence of soils. The amount of L-DOPA adsorbed was largest in the presence of volcanic ash soil among the three soil types. It is likely that the mechanism of L-DOPA adsorption includes a ligand exchange reaction. In the presence of soils, L-DOPA transformation was observed at equilibrium pH values higher than 4 and it increased with increasing equilibrium pH values. In the absence of soil, however, L-DOPA transformation did not occur at an equilibrium pH value lower than 6.0, indicating that L-DOPA transformation was accelerated by the presence of soil. The rate of L-DOPA transformation mediated by soils at constant equilibrium pH value was in the following order: alluvial soil > calcareous soil > volcanic ash soil. The plant-growth-inhibitory activity of L-DOPA was also reduced by the presence of soils, and the reduction in the case of L-DOPA was more obvious than in the case of 2,4-dichlorophenoxyacetic acid (2,4-D). Based on the reduction effect of soils on the plant-growth-inhibitory activity of L-DOPA (without pH-adjustment), calcareous soil ranked first, followed by volcanic ash soil, then alluvial soil. This was because the calcareous soil showed the highest soil pH value (7.8), and thereby the L-DOPA transformation reaction was accelerated. In soils with high pH values, the plant-growth-inhibitory activity of L-DOPA could therefore not be detected..
105. (404) Productivity of N-acylhomoserine Lactones on Phyllosphere Bacteria of Wheat Heads(Abstracts of the Papers Presented at the 2005 Annual Meeting in Shizuoka).
106. Participation of Allelopathy in Injury due to Continuous Cropping of Asparagus (Asparagus officinalis L.) in Alluvial Soil(Crop Production & Cropping Type)
Replanting of asparagus (Asparagus officinalis L.) often results in lower yields and extensive damage of young plants. One of the causes is considered allelopathy. In this study, we examined the participation of allelopathy on injury by continuous cropping of asparagus in alluvial soil. The presence of strong allelochemical substances, which have the growth-inhibitory activity, was detected by bioassay of rhizosphere soil around asparagus. This growth-inhibitory activity was not attributed to salt accumulation, pH fluctuation, or inorganic nutrient imbalance in the rhizosphere soil. Asparag....
107. A Novel Bioassay Method to Evaluate the Allelopathic Activity in Rhizosphere Soil on Asparagus (Asparagus officinalis L.)(Crop Production & Cropping Type)
We developed a new method of examining the effects of allelochemical substances exuded from the roots of asparagus (Asparagus officinalis L.) to rhizosphere soil. This rhizosphere soil bioassay method provided results similar to those from the conventional bioassay method in which asparagus germinates in the soil. The new method was more effective than the conventional bioassay method because the soil samples could be tested using a smaller volume. This method could also evaluate flowable activated carbon as one of the materials to absorb allelochemical substances at a laboratory level. An ....
108. Activated Carbon Utilization to Reduce Allelopathy that Obstructs the Continuous Cropping of Asparagus (Asparagus officinalis L.)(Crop Production & Cropping Type)
The growth-inhibitory activities of allelopathy in asparagus (Asparagus officinalis L.) was studied using the 'Plant Box Method' of bioassay. By this methods we confirmed that asparagus produced allelochemical substances. Then we developed a modified plant box method to examine the relationship between the growth-inhibitory activity and the adsorption of materials to allelochemical substances from asparagus. As a result, a type of activated carbon has the ability to absorb the allelochemical substances and prevent the growth inhibition of lettuce, an assay plant. Furthermore, in a field rep....
109. Sexual differences in allelopathic effects of female and male asparagus roots.
110. Studies on allelopathy of asparagus : 10. Development of allelopathy reduction technology using activated carbon for alleviating the injury associated with continuous cropping of asparagus.
111. Tsunashi Kamo, Masae Sato, Kenji Kato, Syuntaro Hiradate, Eri Nakajima, Yoshiharu Fujii, Mitsuru Hirota, Quantification of cyanamide contents in herbaceous plants, BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 10.1271/bbb.60171, Vol.70, No.9, pp.2310-2312, 2006.09, Cyanamide (NH2CN) is found in nature, although it has long been recognized as an industrial product. Distribution of cyanamide in the plant kingdom was investigated using a direct quantitative determination method to detect and measure cyanamide by stable isotope dilution gas chromatography-mass spectrometry (the SID-GC-MS method). The SID-GC-MS method proved to be a robust way to quantify cyanamide contents in the extracts of 101 species of herbaceous plants. The average recovery of cyanamide from all plants tested was 55.6 +/- 20.3%. Vicia villosa and V. cracca contained cyanamide at 369-498 mu g/gFW and 3,460-3,579 mu g/gFW respectively, while the other 99 species contained no detectable cyanamide (< 1 mu g/gFW). This result suggests that distribution of cyanamide in the plant kingdom is limited and uneven..
112. S Yoshida, LL Kinkel, H Shinohara, N Numajiri, S Hiradate, M Koitabashi, K Suyama, H Negishi, S Tsushima, Production of quorum-sensing-related signal molecules by epiphytic bacteria inhabiting wheat heads, CANADIAN JOURNAL OF MICROBIOLOGY, 10.1139/W05-146, Vol.52, No.5, pp.411-418, 2006.05, The production of quorum-sensing-related signal molecules (QSRMs) among culturable bacteria comprising the community on wheat heads was investigated. The taxonomic position of 186 bacterial isolates obtained from ten heads was inferred based on 16S rRNA gene sequences, and their QSRM production was determined using two bioreporter strains of N-acylhomoserine lactones. Approximately 33% of isolates produced QSRMs, though the proportion of QSRM-producing isolates on a wheat head was significantly negatively correlated with population size. Most of the producing isolates were Pantoea species, most commonly Pantoea ananatis. Furthermore, the proportion of Pantoea ananatis that produced QSRMs was significantly negatively correlated with the number of bacterial genera (community richness) on each head. Finally, community richness was positively correlated with population size. Qualitative analysis using thin-layer-chromatography revealed that the QSRMs of Pantoea isolates were composed of at least two compounds. This is the first report indicating that Pantoea ananatis isolates inhabiting wheat heads are capable of producing QSRMs. QSRM production by Pantoea spp. may contribute to the predominance of this genus on wheat heads, particularly at relatively low population densities and community diversity..
113. PB-15 Deoxynivalenol-degrading soil bacterium isolated from a wheat field(Bioremediation,Session B,(1)Poster Presentation).
114. S Hiradate, T Yonezawa, H Takesako, Isolation and purification of hydrophilic fulvic acids by precipitation, GEODERMA, 10.1016/j.geoderma.2005.05.007, Vol.132, No.1-2, pp.196-205, 2006.05, Fulvic acids play an important role in the behavior of metals and hydrophobic organic chemicals in soil and water environments. The isolation and purification of the fulvic acids have been difficult to achieve, however, because these compounds are soluble in both alkaline and acidic solution, resulting in difficulty of dehydration and demineralization. We propose here a new procedure for isolating fulvic acids as precipitates. Our procedure includes pH-adjustment of the fulvic acid solution to weakly acidic to neutral pH range (4 to 7). In an Andisol, recoveries of the fulvic acids we prepared by precipitation at equilibrium pH of 5.0 were 86% (dissolved total organic carbon basis) and 97% (absorbance basis, 400 nm), whereas recoveries of fulvic acids adsorbed on XAD-8 resin (hydrophobic fulvic acids) were 14% and 28%, respectively. Recoveries of the fulvic acids were further increased in our procedure by adding Al. The mechanism forming the precipitates includes a complexation reaction of carboxylic groups of the fulvic acids with Al (ligand exchange reaction); this mechanism is identical to that for the retention of fulvic acids in many soils. Therefore, it is likely that our preparation procedure is appropriate for separating the fulvic acids stabilized in soils. Solid-state cross polarization and magic angle spinning C-13 nuclear magnetic resonance spectra showed that the fulvic acids prepared by our precipitation procedure were relatively rich in O-alkyl carbons and poor in aromatic and alkyl carbons compared with those forms from the hydrophobic fulvic acids adsorbed on XAD-8 resin. A new scheme for preparing the hydrophobic and hydrophilic fulvic acids is also proposed here. The hydrophilic fulvic acids are likely to maintain high solubilities in water even after the formation of complexes with metals and may influence on their behavior. (c) 2005 Elsevier B.V. All rights reserved..
115. T Kamo, K Kato, S Hiradate, E Nakajima, Y Fujii, M Hirota, Evidence of cyanamide production in hairy vetch Vicia villosa, NATURAL PRODUCT RESEARCH, 10.1080/14786410500143583, Vol.20, No.5, pp.429-433, 2006.05, Cyanamide (NH2CN) has recently been isolated as a plant growth inhibitor from Vicia villosa, which is the first discovery of cyanamide from natural sources. To reveal the presence of the biosynthesized cyanamide in plants, 3.4 mM potassium (N-15) nitrate was administered to 15- to 35-day-old plants of V. villosa, from which the cyanamide was purified and subjected to GC/MS analysis. The isotopic ratio N-15/(N-14+N-15) of the cyanamide was calculated to be 0.143, while that of the cyanamide extracted from V. villosa grown in the presence of a natural N source was 0.0065. The N-15-enrichment proved de novo biosynthesis of cyanamide..
116. Syuntaro Hiradate, Hideaki Hirai, Hitoshi Hashimoto, Characterization of allophanic Andisols by solid-state 13C, 27Al, and 29Si NMR and by C stable isotopic ratio, δ13C, Geoderma, 10.1016/j.geoderma.2006.05.007, Vol.136, No.3-4, pp.696-707, 2006.12.
117. 49.Distribution of cyanamide among higher plants.
118. Overview of General Presentations and Messages Mediated by the Congress(Report on the 18th World Congress of Soil Science).
119. Varietal differences in allelopathic effects of asparagus seedlings.
120. Aseptic bioassay for estimation of asparagus allelopathic effects toward asparagus seeds.
121. Akihiro Furubayashi, Syuntaro Hiradate, Yoshiharu Fujii, Role of catechol structure in the adsorption and transformation reactions of L-DOPA in soils, JOURNAL OF CHEMICAL ECOLOGY, 10.1007/s10886-006-9218-5, Vol.33, No.2, pp.239-250, 2007.02, 3-( 3',4'-Dihydroxyphenyl)-L-alanine ( L-DOPA), which is synthesized in velvet bean ( Mucuna pruriens), inhibits plant growth. The concentration of L-DOPA in soil is reduced by adsorption and transformation reactions, which can result in the reduction of its plant-growth-inhibitory activity. To determine which part of the L-DOPA structure is involved in the adsorption and soil transformation reactions, we compared the kinetics of L-DOPA disappearance in a volcanic ash soil with that of L-phenylalanine ( 3-phenyl-Lalanine) and L-tyrosine ( 3-( 4'-hydroxyphenyl)-L-alanine), compounds that are similar in structure to L-DOPA but do not have a catechol ( o-dihydroxybenzene) moiety. L-Phenylalanine and L-tyrosine were not adsorbed and transformed in the soil at equilibrium pH values between 4 and 7. These results suggest that the adsorption and transformation reactions of L-DOPA in the soil involve the catechol moiety and not the amino and carboxylic acid groups, which are common to all three compounds. Like L-DOPA, (+)catechin, another allelochemical that contains a catechol moiety, underwent adsorption and soil transformation reactions. Thus, we concluded that the concentrations of allelochemicals bearing a catechol moiety in soils will decrease rapidly owing to adsorption and transformation reactions, and this decrease will be faster in soils with a high pH value or high adsorption ability. Owing to this decrease in concentration, allelopathic phenomena may not occur..
122. Syuntaro Hiradate, Takuya Yonezawa, Hiroshi Takesako, Fine fractionation and purification of the fulvic acid fraction using adsorption and precipitation procedures, SOIL SCIENCE AND PLANT NUTRITION, 10.1111/j.1747-0765.2007.00159.x, Vol.53, No.4, pp.413-419, 2007.08, A new scheme for fine fractionating and purifying a crude fulvic acid fraction was proposed. The fractionation procedure includes an adsorption process of the fulvic acid fraction on a hydrophobic resin (e.g. XAD-8 and DAX-8) and a sequence of successive elution processes. This procedure yields a non-adsorbed fraction (FA-1), a 0.1 mol L-1 HCl eluted fraction (FA-2), a distilled water eluted fraction (FA-3) and a 0.1 mol L-1 NaOH eluted fraction (FA-4). To remove salts and water, the fractionated organic molecules were co-precipitated with Al hydroxides at pH 5 and collected by centrifugation. Recoveries of carbon from the crude fulvic acid fraction of an Andosol were 42, 20, 19 and 14% for FA-1, FA-2, FA-3 and FA-4, respectively, and 96% of carbon was recovered in total. Optical properties and 13 C nuclear magnetic resonance spectra indicated that the chemical properties of FA-I were similar to those of FA-2 and were hydrophilic, while the chemical properties of FA-3 were very close to those of FA-4 and were hydrophobic (estimated hydrophobicity: humic acid >> FA-4 ! FA-3 >> FA-2 >= FA-1). A fulvic acid that can be isolated using the International Humic Substances Society method would be, in practice, a mixture of hydrophilic fulvic acid (FA-2) and hydrophobic fulvic acid (FA-3 + FA-4). The method developed in the present study will provide more detailed, quantitative and complete information of the fulvic acid fraction of soils..
123. Tsutomu Ohno, Ivan J. Fernandez, Syuntaro Hiradate, Jessica F. Sherman, Effects of soil acidification and forest type on water soluble soil organic matter properties, GEODERMA, 10.1016/j.geoderma.2007.04.004, Vol.140, No.1-2, pp.176-187, 2007.06, Dissolved organic matter (DOM) plays an important role in ecosystem processes such as nutrient release and utilization, mobilization and transport of metals, and carbon sequestration. We investigated the chemical properties of soils from the Bear Brook Watershed in Maine (BBWM) which is the site of a long-term paired-watershed experimental acidification study that includes both deciduous and coniferous stands. Multidimensional fluorescence spectroscopy combined with parallel factor analysis (PARAFAC) of the spectra, nuclear magnetic resonance spectroscopy, and size-exclusion chromatography, were used to characterize the DOM extracted from soils sampled from BBWM at four soil depth increments in 2003. Principal component analysis of the base cation, metal, and total C content of the mineral horizons indicated a strong negative relationship between pH and soil At, Fe, P, and C. The close clustering of Al, Fe, P, and C loadings for the mineral soils suggests that organic matter is important for At and Fe mobilization and that P solubility is influenced by the metal mobilization process. PARAFAC modeled the fluorescence spectra with three fluorescing components that were in the landscape regions typical of humic substances: (339 nm excitation/470 nm emission), (324 nm/418 nm), and (<240/465 nm) and the relative distributions of the three components were similar amongst the four treatments and four soil depth increments. The size exclusion chromatograms also revealed a high degree of similarity between all the extracted DOM. Our data suggests that litter quality as influenced by forest composition and ecosystem acidification exert a minor influence on the chemical composition of the water-soluble soil DOM fraction. (C) 2007 Elsevier B.V. All rights reserved..
124. M. Watanabe, Y. Inoue, N. Sakagami, O. Bolormaa, K. Kawasaki, S. Hiradate, N. Fujitake, H. Ohta, Characterization of major and trace elements in sclerotium grains, EUROPEAN JOURNAL OF SOIL SCIENCE, 10.1111/j.1365-2389.2006.00868.x, Vol.58, No.3, pp.786-793, 2007.06, Sclerotium grains in soil contain humus-metal complexes that are probably produced from fungal metabolites. The characterization of major elements in sclerotium grains collected from volcanic ash soils in Mt Myoko was examined by X-ray photoelectron spectroscopy, FT-IR spectrometry and CHN analysis, and the concentration of trace elements was determined by PIXE (particle induced X-ray emission spectrometer) analysis. The content of major elements, C, H, N, O and Al, was approximately 47.6, 3.32, 0.78, 30.2 and 1.4% by mass, respectively. Trace elements such as Ti, Cr, Mn, Cu, Zn, Br and Pb were detected in the grains at concentrations between 10 and 100 mu g g(-1). Functional carbon groups for the whole grain were characterized by the dominance of O-alkyl C associated with aromatic C. The comparison between the surface and subsurface (matrix) of the grain showed that the concentrations of O, C and N were relatively greater on the surface of sclerotium grains than in the matrix. The proportion of carbon having C-O, C=O, and O-C=O bonds, O and N showed a tendency to decrease from the surface towards the matrix. The proportion of C assigned as C-C and/or C-H bonds had a tendency to increase towards the matrix associated with Al..
125. C404 The antimicrobial effect of the antimicrobial substances contained in Geranium carolinianum L. in soil.
126. Kunihiko Fujii, Kazuhiro Takagi, Syuntaro Hiradate, Akio Iwasaki, Naoki Harada, Biodegradation of methylthio-s-triazinessd where science by Rhodococcus sp strain FJ1117YT, and production of the corresponding methylsulfinyl, methylsulfonyl and hydroxy analogues, PEST MANAGEMENT SCIENCE, 10.1002/ps.1331, Vol.63, No.3, pp.254-260, 2007.03, A novel bacterial strain FJ1117YT was isolated from an enrichment culture with the herbicide simetryn. The isolate was capable of degrading the herbicide supplied as the sole sulfur source in an aquatic batch culture. The strain FJ1117YT was identified as that belonging to Rhodococcus sp. on the basis of comparative morphology, physiological characteristics and comparison of the 16S rRNA gene sequence. The biodegradation pathway of simetryn was established by isolating the methylsulfinyl analogue as the first metabolite and by identification of the methylsulfonyl intermediate and the hydroxy analogue by liquid chromatography-mass spectrometry (LC-MS) and/or nuclear magnetic resonance (NMR) analysis. The results indicate that the methylthio group was progressively oxidised and hydrolysed by the strain FJ1117YT. The same strain is also able to metabolise other methylthio-s-triazines such as ametryn, desmetryn, dimethametryn and prometryn through similar pathways. (c) 2007 Society of Chemical Industry..
127. Tadashi TAKAHASHI, Masami NANZYO, Syuntaro HIRADATE, Aluminum status of synthetic Al–humic substance complexes and their influence on plant root growth, Soil Science and Plant Nutrition, 10.1111/j.1747-0765.2007.00114.x, Vol.53, No.2, pp.115-124, 2007.04.
128. Syuntaro Hiradate, Akihiro Furubayashi, Natsuyo Uchida, Yoshiharu Fujii, Adsorption of 2,4-dichlorophenoxyacetic acid by an Andosol, JOURNAL OF ENVIRONMENTAL QUALITY, 10.2134/jeq2005.0415, Vol.36, No.1, pp.101-109, 2007.01, To identify the important soil components involved in 2,4-dichlorophenoxyacetic acid (2,41-D) adsorption on Andosols, 2,4-D adsorption on a surface horizon of an Andosol was compared with that on hydrogen peroxide (H2O2)-treated (soil organic matter [SOM] was removed), acid-oxalate (OX)-treated (active metal hydroxides and SOM were removed), and dithionite-citrate-bicarbonate (DCB)-treated (free and active metal [hydr]oxides and SOM were removed) soil samples at equilibrium pHs ranging from 4 to 8. Although the untreated soil contained a large amount of organic C (71.9 g kg(-1)), removal of SOM had little effect on 2,4-D adsorption. Active surface hydroxyls, which were attached to the active and free metal (hydr)oxides and metal SOM complexes, were identified as the most important soil functional group for 2,4-D adsorption. The dominant mechanism of the 2,4-D adsorption was a ligand exchange reaction in which the carboxylic group of 2,4-D displaced the active surface hydroxyl associated with metals and formed a strong coordination bond between the 2,4-D molecule and soil solid phase. The ligand exchange reaction reasonably accounted for the selective adsorption of 2,4-D over Cl-, competitive adsorption of phosphate over 2,4-D, reduction in plant-growth-inhibitory activity of soil-adsorbed 2,4-D, and the high 2,4-D adsorption ability of Andosols. Although a humic acid purified from the soil did not adsorb 2,4-D, the presence of the humic acid increased 2,4-D adsorption on Al and Fe, probably by inhibiting the hydrolysis and polymerization of Al and Fe resulting in the preservation of available adsorption sites on these metals. The adsorption behavior of 2,4-D on soils could be a good index for predicting the adsorption behavior of other organic acids in soils..
129. 68. Cyanamide-biosynthesizing organ in hairy vetch Vicia villosa subsp. varia
Cyanamide (NH_2CN) has been isolated from hairy vetch Vicia villosa subsp. varia as a natural product for the first time. We have already clarified that the cyanamide content in hairy vetch seedlings cultivated in the growth chamber reaches its maximum at 3-4 week. The present study aims at elucidating the organ in which cyanamide is biosynthesized. The cyanamide contents in the leaves, the stems, and the roots of 4-week-old seedlings were 629 ± 209, 256 ± 134, and < 20 μg/gFW (average ± SD), respectively. This suggests that cyanamide is biosynthesized in the aerial parts (the leaves plus t....
130. Makiko WATANABE, Hiroyuki SATO, Hiroyuki MATSUZAKI, Takayuki KOBAYASHI, Nobuo SAKAGAMI, Yuji MAEJIMA, Hiroyuki OHTA, Nobuhide FUJITAKE, Syuntaro HIRADATE, 14C ages and δ13C of sclerotium grains found in forest soils, Soil Science and Plant Nutrition, 10.1111/j.1747-0765.2007.00121.x, Vol.53, No.2, pp.125-131, 2007.04.
131. (78) Deoxynivalenol- degrading Bacteria Isolated from a Wheat Field(Abstracts of the Papers Presented at the Annual Meeting of the Society).
132. Effects of soil chemical properties on the habitats of alien and endemic plants.
133. Speciation and behavior analyses of trace elements using a synchrotron radiation light source : application to plant and soil samples.
134. Influence of light quality on allelopathic effects of asparagus through aseptic bioassay.
135. Akio Tani, Chiemi Inoue, Yoko Tanaka, Yoko Yamamoto, Hideki Kondo, Syuntaro Hiradate, Kazuhide Kimbara, Fusako Kawai, The crucial role of mitochondrial regulation in adaptive aluminium resistance in Rhodotorula glutinis, MICROBIOLOGY-SGM, 10.1099/mic.0.2007/016048-0, Vol.154, No.11, pp.3437-3446, 2008.11, Rhodotorula glutinis IFO1125 was found to acquire increased aluminium (Al) resistance from 50 mu M to more than 5 mM by repetitive culturing with stepwise increases in Al concentration at pH 4.0. To investigate the mechanism underlying this novel phenomenon, wild-type and Al- resistant cells were compared. Neither cell type accumulated the free form of Al (Al3+) added to the medium. Transmission electron microscopic analyses revealed a greater number of mitochondria in resistant cells. The formation of small mitochondria with simplified cristae structures was observed in the wild-type strain grown in the presence of Al and in resistant cells grown in the absence of Al. Addition of Al to cells resulted in high mitochondrial membrane potential and concomitant generation of reactive oxygen species (ROS). Exposure to Al also resulted in elevated levels of oxidized proteins and oxidized lipids. Addition of the antioxidants a-tocopherol and ascorbic acid alleviated the Al toxicity, suggesting that ROS generation is the main cause of Al toxicity. Differential display analysis indicated upregulation of mitochondrial genes in the resistant cells. Resistant cells were found to have 2.5- to 3-fold more mitochondrial DNA (mtDNA) than the wild-type strain. Analysis of tricarboxylic acid cycle and respiratory-chain enzyme activities in wild-type and resistant cells revealed significantly reduced cytochrome c oxidase activity and resultant high ROS production in the latter cells. Taken together, these data suggest that the adaptive increased resistance to Al stress in resistant cells resulted from an increased number of mitochondria and increased mtDNA content, as a compensatory response to reduced respiratory activity caused by a deficiency in complex IV function..
136. Akio Morita, Osamu Yanagisawa, Satoshi Takatsu, Setsuko Maeda, Syuntaro Hiradate, Mechanism for the detoxification of aluminum in roots of tea plant (Camellia sinensis (L.) Kuntze), PHYTOCHEMISTRY, 10.1016/j.phytochem.2007.06.007, Vol.69, No.1, pp.147-153, 2008.01, To determine the mechanism of aluminum (Al) detoxification in the roots of tea plants (Camellia sinensis (L.) Kuntze), the amounts of Al and Al-chelating compounds (fluoride (F), organic acids and catechins) were measured and the chemical forms of A, in root cell extracts were identified by the application of Al-27-nuclear magnetic resonance (NMR) spectroscopy. Tea plants were cultivated in nutrient solutions containing 0, 4, 1.0 and 4.0 mM of Al at pH 4.2 for approximately 10 weeks. The levels of soluble Al, water-soluble oxalate and citrate, but not F, malate or catechins in young roots increased with an increase in the concentration of Al in the treatment solution. The Al-27 NMR spectra of root tips and cell sap extracted from root tips that had been treated with Al were almost identical and had four signals, with two (11 and 16 ppm) apparently corresponding to the known chemical shifts of Al-oxalate complexes. In the spectra of cell sap, the resonances at 11 and 16 ppm increased with an increase in the Al contents. These results suggest that the levels of Al-oxalate complexes increased in response to an increase in the Al level, implying that oxalate is a key Al-chelating compound in the mechanism of Al detoxification in the tea root. (C) 2007 Elsevier Ltd. All rights reserved..
137. Tsunashi Kamo, Mai Endo, Masae Sato, Ryohei Kasahara, Hiroko Yamaya, Syuntaro Hiradate, Yoshiharu Fujii, Nobuhiro Hirai, Mitsuru Hirota, Limited distribution of natural cyanamide in higher plants: Occurrence in Vicia villosa subsp varia, V. cracca, and Robinia pseudo-acacia, PHYTOCHEMISTRY, 10.1016/j.phytochem.2007.11.004, Vol.69, No.5, pp.1166-1172, 2008.03, Cyanamide (NH2CN) has recently been proven to be a natural product, although it has been synthesized for over 100 years for agricultural and industrial purposes. The distribution of natural cyanamide appears to be limited, as indicated by our previous investigation of 101 weed species. In the present study, to investigate the distribution of natural cyanamide in Vicia species, we monitored the cyanamide contents in V villosa subsp. varia, V cracca, and V amoena during their pre-flowering and flowering seasons. It was confirmed that V cracca was superior to V villosa subsp. varia in accumulating natural cyanamide, and that V amoena was unable to biosynthesize this compound under laboratory condition examined. The localization of cyanamide in the leaves of V villosa subsp. varia seedlings was also clarified. In a screening study to find cyanamide-biosynthesizing plants, only Robinia pseudo-acacia was found to contain cyanamide among 452 species of higher plants. We have investigated 553 species to date, but have so far found the ability to biosynthesize cyanamide in only three species, V villosa subsp. varia, V. cracca and R. pseudo-acacia. (c) 2007 Elsevier Ltd. All rights reserved..
138. Masami Takita, Hajime Sugie, Jun Tabata, Syoichi Ishii, Syuntaro Hiradate, Isolation and estimation of the aggregation pheromone from Eysarcoris lewisi (Distant) (Heteroptera : Pentatomidae), APPLIED ENTOMOLOGY AND ZOOLOGY, 10.1303/aez.2008.11, Vol.43, No.1, pp.11-17, 2008.02, A male-produced crude aggregation pheromone from Eysarcoris lewisi (Distant) (Heteroptera: Pentatomidae) was collected from volatiles emitted by adult males. It was purified with high performance liquid chromatography using a silica gel column, followed by preparative gas chromatography. The attraction activity of each fraction was field tested using water pan traps. The isolated compound of the aggregation pheromone component was analyzed by GC-MS and NMR, and the chemical structure was estimated to be (Z)-2-methyl-6-(4-methylenebicyclo[3.1.0]hex-1-yl)hept-2-enl-o1..
139. Hajime Sugie, Mayumi Teshiba, Yutaka Narai, Takafumi Tsutsumi, Nobuo Sawamura, Jun Tabata, Syuntaro Hiradate, Identification of a sex pheromone component of the Japanese mealybug, Planococcus kraunhiae (Kuwana), APPLIED ENTOMOLOGY AND ZOOLOGY, 10.1303/aez.2008.369, Vol.43, No.3, pp.369-375, 2008.08, A sex pheromone component of the Japanese mealybug, Planococcus kraunhiae, was isolated and identified. A crude extract of the pheromone obtained by airborne collection was first fractionated with Florisil column chromatography. The activity of each fractionated sample was examined in Petri dishes. The active fraction was further purified by HPLC and an active component was isolated by preparative GC. The purified compound showed attraction activity to adult males of P. kraunhiae in the field. The chemical structure was determined to be 2-isopropyliden-5-methyl-4-hexen-1-yl butyrate by GC-MS and NMR analyses..
140. Kenji Mori, Takuya Tashiro, Tomoko Yoshimura, Masami Takita, Jun Tabata, Shyuntaro Hiradate, Hajime Sugie, Determination of the absolute configuration of the male aggregation pheromone, 2-methyl-6-(4′-methylenebicyclo[3.1.0]hexyl)hept-2-en-1-ol, of the stink bug Erysarcoris lewisi (Distant) as 2Z,6R,1′S,5′S by its synthesis, Tetrahedron Letters, 10.1016/j.tetlet.2007.11.036, Vol.49, No.2, pp.354-357, 2008.01.
141. Toshihiro Watanabe, Seiji Misawa, Syuntaro Hiradate, Mitsuru Osaki, Characterization of root mucilage from Melastoma malabathricum, with emphasis on its roles in aluminum accumulation, NEW PHYTOLOGIST, 10.1111/j.1469-8137.2008.02397.x, Vol.178, No.3, pp.581-589, 2008.05, Plant roots exude viscous polysaccharides, called mucilage. One of the suggested roles of mucilage is immobilization of toxic metal cations, including aluminum (Al), in the rhizosphere.
Mucilage exuded from roots of Melastoma malabathricum (Al accumulator) was characterized in comparison with that of Zea mays (maize; Al nonaccumulator).
Removal of mucilage significantly reduced Al accumulation in M. malabathricum. The cation adsorption affinity of M. malabathricum mucilage was higher for Al and lanthanum (La) than for barium (Ba), whereas that of maize mucilage was in the order Ba > La > Al. A (27)Al nuclear magnetic resonance (NMR) spectrum of the Al-adsorbed mucilage and bioassay with alfalfa seedlings indicated that the concentrated Al in the mucilage of M. malabathricum, unlike that of maize, bound very weakly to cation exchange sites of mucilage.
The higher charge density in M. malabathricum mucilage, derived from unmethylated uronic acid, is inferred to be related to preferential adsorption of trivalent cation. Not only a higher degree of methylation in the uronic acid (glucuronic acid) but also H(+) release from roots to the mucilage appears to be responsible for the loose binding of Al in M. malabathricum mucilage. These characteristics of mucilage may help Al hyperaccumulation in M. malabathricum..
142. Kentaro Hayashi, Syuntaro Hiradate, Satoru Ishikawa, Isamu Nouchi, Ammonia exchange between rice leaf blades and the atmosphere: Effect of broadcast urea and changes in xylem sap and leaf apoplastic ammonium concentrations, SOIL SCIENCE AND PLANT NUTRITION, 10.1111/j.1747-0765.2008.00299.x, Vol.54, No.5, pp.807-818, 2008.10, To elucidate the effects of broadcast urea on ammonia (NH(3)) exchange between the atmosphere and rice, we investigated the NH(3) exchange flux between rice leaf blades and the atmosphere, xylem sap ammonium (NH(4)(+)) concentration, leaf apoplastic NH(4)(+) concentration and pH, and determined the stomatal NH(3) compensation point. Paddy rice (Oryza sativa L. cv. Nipponbare) cultivation using experimental pots was conducted in the open air. Three treatments, no nitrogen (NN), standard nitrogen (SN) and high nitrogen (HN), were prepared for two supplemental fertilizations. Urea with 0, 30 and 60 kg N ha(-1) for the NN, SN and HN treatments, respectively, was broadcast at panicle initiation, and urea with 0, 20 and 40 kg N ha(-1) for the NN, SN and HN treatments, respectively, was broadcast at heading. The NH(3) exchange fluxes between the rice leaf blades and the atmosphere (SN treatment) measured using a dynamic chamber technique showed net deposition in general; however, net emission from the old leaves occurred 1 day after the application at heading. In contrast, the xylem sap NH(4)(+) concentrations increased markedly 1 day after both applications, which suggests direct transportation of NH(4)(+) from the rice roots to the above-ground parts. The applications resulted in no obvious increase in the leaf apoplastic NH(4)(+) concentrations. The relationship between the NH(4)(+) concentration in the xylem sap and that in the leaf apoplast was uncertain, although the NH(4)(+) in the xylem sap came from the roots and the NH(4)(+) in the apoplast might be affected by the stomatal deposition of NH(3). The stomatal NH(3) compensation point of rice was estimated to be 0.1-4.1 nmol mol(-1) air (20 degrees C). The direction and intensity of the exchange flux through the stomata, interpreted on the basis of the temperature-corrected NH(3) compensation point, agreed with the observed exchange flux between the rice leaf blades and the atmosphere..
143. Hirotatsu Murano, Takashi Otani, Akihiro Furubayashi, Kohji Yamamura, Katsuichiro Kobayashi, Syuntaro Hiradate, Adsorption of herbicidally active degradate 2-(2,4-dichloro-3-methylphenoxy)propanoic acid on an andosol, JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY, 10.1021/jf0729816, Vol.56, No.4, pp.1350-1357, 2008.02, The adsorption of 2-(2,4-dichloro-3-methylphenoxy)propanoic acid (DMPA) on the surface horizon of a humus-rich Andosol was examined. To investigate the mechanisms of adsorption, chemically treated Andosols, such as organic matter removed Andosol, organic matter and active metals removed Andosol, and clay minerals of the Andosol, were prepared. Furthermore, humic acid was extracted from the Andosol. The mechanisms of the DMPA adsorption were identified by using those untreated and chemically treated Andosols and the humic acid. The amount of DMPA adsorbed increased with decreasing equilibrium pH value. Active surface hydroxyl groups were identified as the most important soil functional group in DMPA adsorption. The predominant mechanism of DMPA adsorption on the Andosol is a ligand-exchange reaction, in which an active surface hydroxyl on Al and/or Fe is replaced by a carboxylic group of DMPA. A comparative study revealed that the amount of DMPA adsorbed was slightly greater than that of (2,4-dichlorophenoxy)acetic acid (2,4-D), especially at equilibrium pH values below 5. This is because the octanol-water partition coefficient (log K(ow),) of DMPA in the equilibrium pH range is higher than that of 2,4-D, and SOM participates in the adsorption process through a hydrophobic interaction..
144. 70. Establishment of life cycle assessment (LCA) and analysis of allelochemicals mode of action through DNA microarray
Plants life cycle starts from germination, then early vegetative growth, maturing stage, finally regeneration stage and seed formation. We have already developed assessment methods for allelopathy during the early growth stage. The present study aims at the evaluation of Allelopathic effect in the whole life cycle of plants. Establishment of Life cycle assessment (LCA): Sterilized seeds of Arabidopsis thaliana were sown in an Agripot containing 1% agar with Murashige and Skoog Medium and 1% sucrose. Plants were maintained for 7 weeks, until seed formation. Triple plant box apparatus was mad....
145. 69. Biosynthetic origin of nitrogen and carbon atoms in cyanamide biosynthesis
Natural cyanamide (NH_2CN) has recently proved to occur in some Leguminosae plants including hairy vetch Vicia villosa subsp. varia. In the present study, we demonstrated the incorporation of ^<15>N and ^<13>C from labeled precursors into cyanamide using shoots of V. villosa subsp. varia. We incubated the 3-week-old shoots in the presence of 5μM of H^<13>CN for 24h and in the absence for another 48h. As a result of GCMS analysis of the cyanamide isolated from the shoots, direct incorporation of the cyano group of H^<13>CN into cyanamide was not observed. By the administration of five ^<15>N....
146. Kenji Ono, Keizo Hirai, Sayaka Morita, Kenji Ohse, Syuntaro Hiradate, Organic carbon accumulation processes on a forest floor during an early humification stage in a temperate deciduous forest in Japan: Evaluations of chemical compositional changes by C-13 NMR and their decomposition rates from litterbag experiment, GEODERMA, 10.1016/j.geoderma.2009.05.001, Vol.151, No.3-4, pp.351-356, 2009.07, To quantitatively clarify the organic carbon accumulation processes on the forest floor during an early stage of humification (3 years), solid-state C-13 cross polarization magic angle spinning nuclear magnetic resonance (CPMAS NMR) signals were monitored for phased-humified beech and oak litters and soil surface horizons in the northern Kanto District, Japan. The mass loss rate of the carbon components during the humification for both litters was in the following order: O-alkyl > aromatic > aliphatic > carbonyl carbons. This result indicates that the labile O-alkyl carbons, probably dominated by holocellulose were selectively degraded compared to the other components. 44% of O-alkyl carbon mass for beech and 38% for oak lost throughout 3 years of incubation. Inversely, the mass of aliphatic carbons, which is mainly composed of saturated hydrocarbons, decreased quite slowly from 20 to 10% with humification, probably because a large proportion of the aliphatic carbons are secondary products of microorganisms. The aromatic carbon mass, which would be derived from lignin/tannin and their metabolites, also decreased gradually from 17 to 6% over 3 years. While, the carbonyl carbon mass was quite stable at around 2% throughout the incubation period. probably because the hydrolysis reactions of organic carbon would contribute to the formation of the carbonyl carbons. According to an exponential model, the total carbon stocks on the forest floor converged at 4.2 Mg C ha(-1) for the first few years at the studying site. The carbon compositions converged to intermediate levels between those of the F and A(1) horizons. The simulation in the present study is able to represent the carbon accumulation process on the forest floor including a part of the mineral. (C) 2009 Elsevier B.V. All rights reserved..
147. Atsushi Ooshiro, Syuntaro Hiradate, Shinji Kawano, Tetsuya Takushi, Yoshiharu Fujii, Masahiro Natsume, Hiroshi Abe, Identification and activity of ethyl gallate as an antimicrobial compound produced by Geranium carolinianum, WEED BIOLOGY AND MANAGEMENT, 10.1111/j.1445-6664.2009.00335.x, Vol.9, No.2, pp.169-172, 2009.06, We isolated an antimicrobial compound from the aerial tissue of Geranium carolinianum and identified it as ethyl 3, 4, 5-trihydroxy benzoate (ethyl gallate) by (1)H-NMR and (13)C-NMR and gas chromatography-mass spectrometry. The antimicrobial activity of ethyl gallate against three potato pathogens was assayed by the paper disk method. The activity against Ralstonia solanacerum, Streptomyces scabies, and Streptomyces acidiscabies was observed at concentrations > 200, > 300, and > 300 mu g disk(-1), respectively. These results suggest that the antimicrobial activity of Geranium carolinianum against soil-borne plant disease pathogens is partly related to ethyl gallate..
148. Tsunashi Kamo, Kenji Kato, Shun Abe, Mitsuru Hirota, Hiroko Yamaya, Syuntaro Hiradate, Yoshiharu Fujii, Biosynthetic origin of the nitrogen atom in cyanamide in Vicia villosa subsp varia, SOIL SCIENCE AND PLANT NUTRITION, 10.1111/j.1747-0765.2008.00354.x, Vol.55, No.2, pp.235-242, 2009.04, Natural cyanamide (NH2CN) has recently been found in three Leguminosae plants: Vicia villosa subsp. varia, Vicia cracca and Robinia pseudo-acacia. As cyanamide has long been thought to be absent in nature, its physiological role and biosynthesis are totally unknown. In the present study, we demonstrated the incorporation of N-15 from [N-15]nitrate and [N-15]ammonium into cyanamide using shoots of V. villosa subsp. varia, which ruled out the possibility that nodules are essential in cyanamide biosynthesis. We also applied [N-15(2)]cyanamide to shoots of V. villosa subsp. varia to monitor its turnover, and detected [N-15(2)]cyanamide in the leaves within 4 h; it was present without detectable degradation for more than 4 days. In contrast, maximum incorporation of N-15 into cyanamide molecules was observed after 4 days of feeding the shoots with N-15-labeled inorganic ions and l-[amide-N-15]-glutamine, indicating that these nitrogenous compounds are distant precursors of cyanamide. Although the guanidino group of l-arginine (-NH-C(NH2)=NH) and urea (NH2C(=O)NH2) were candidate precursors of cyanamide on the basis of structural similarity, direct incorporation of the guanidino group of l-[C-13(6),N-15(4)]-arginine and [C-13,N-15(2)]urea into cyanamide was not observed. These results eliminated the possibility that cyanamide is biosynthesized by the addition of ammonia to an electrophilic carbon or by the conversion of the tested compounds that were structurally relevant to cyanamide..
149. 土壌物理分画と同位体分析から見えてくる土壌有機物の分解と安定化プロセス.
150. S1-36 土壌物理分画と同位体分析から見えてくる土壌有機物の分解と安定化プロセス(S1.安定・放射性同位体を用いた土壌炭素動態研究 -何がどこまで分かるのか?-,2010年度北海道大会).
151. Syuntaro Hiradate, Kenji Ohse, Akihiro Furubayashi, Yoshiharu Fujii, Quantitative Evaluation of Allelopathic Potentials in Soils: Total Activity Approach, WEED SCIENCE, 10.1614/WS-D-09-00085.1, Vol.58, No.3, pp.258-264, 2010.07, The allelopathic potential of a plant has been evaluated on the basis of two indicators: specific activity, which is the specific concentration of the allelochemical to exert a half-maximum effect on a receiver plant (EC(50)), and total activity in a plant, which is the ratio of the concentration of an allelochemical in the producing plant to its EC(50). In the present study, a new indicator, total activity in a soil, which takes into account the effects of a soil on the allelopathy activity, is proposed because allelopathic activity is affected by the presence of soils. The total activity in a soil was calculated by multiplying the "total activity in a plant" with a "soil factor." In this calculation, we assumed simplified cases for comparison, such that the allelopathic plant materials are evenly incorporated in the soils and the allelochemicals are released from the plant materials to the soils at a constant rate. We conducted bioassay experiments in the presence and absence of soils and cited some published data to calculate the specific activities and total activities in a plant and in a soil. The results indicated that the allelopathies of buckwheat caused by (+)-catechin, Leucaena leucocephala by L-mimosine, Xanthium occidentale by transcinnamic acid, and Brassica parachinensis by cis-cinnamic acid were not significant in a volcanic ash soil, an alluvial soil, and a calcareous soil, but the allelopathy of sweet vernalgrass caused by coumarin and Spiraea thunbergii by cis-cinnamoyl glucosides was highly effective in those soils. The allelopathies of Juglans species caused by juglone plus juglone precursors and Mucuna pruriens by L-DOPA would depend highly on the soil types. Although some limitations exist for this approach, the total activity approach would allow for a better quantitative estimation of the allelopathic potential of plant materials in soils..
152. 阿蘇の草原における表層土壌の化学特性と管理手法の関係.
153. 広島県北広島町千町原の半自然草地における植物の分布と土壌特性の関係.
154. 土壌炭素プールの温暖化応答—微生物分解の温度依存性を規定する因子の解明.
155. Kenji Ono, Syuntaro Hiradate, Sayaka Morita, Kenji Ohse, Keizo Hirai, Humification processes of needle litters on forest floors in Japanese cedar (Cryptomeria japonica) and Hinoki cypress (Chamaecyparis obtusa) plantations in Japan, PLANT AND SOIL, 10.1007/s11104-010-0397-z, Vol.338, No.1-2, pp.171-181, 2011.01, We quantitatively clarified the early humification processes on Japanese cedar and Hinoki cypress forest floors by using a litterbag experiment and the solid-state C-13 CPMAS NMR technique. There was no significant effect on litter mass loss during early humification between both coniferous litters regardless of the shape of their needles. Carbon composition in both litters showed similar trends during early humification. A/O-A as a humification index was low, around 0.6, in both litters throughout the experiment period although 60% of litter mass was lost. Coniferous litter incubated for 3 years might not be well-humified and would be susceptible to physical fragmentation. Carbon mass loss rates in conifers were in the following order: O-alkyl > aliphatic > aromatic > carbonyl carbons, differing with hardwoods. Conifers had concomitantly higher and lower mass loss rates of aliphatic and aromatic carbons than hardwoods. Soil organic carbon (SOC) accumulated in topsoil for conifers had relatively high and low contents of aliphatic and aromatic carbons than that for hardwood. These compositional differences of SOC among forests could be caused by the high and low supply rates of aliphatic and aromatic carbons from litter to topsoil. Consequently, initial litter nature and humification processes can affect the compositional qualities of SOC accumulated in soil..
156. ユキヤナギのアレロケミカルはオーキシン早期応答遺伝子群の発現を誘導する.
157. 温度上昇が土壌炭素の分解をどのぐらい加速させるかを決める要因の解明―土壌炭素動態モデルの精緻化に有効―.
158. 土壌団粒内で起こる土壌有機物の長期的動態を物理分画アプローチから考察する―Part 2:走査型透過軟X線顕微鏡を用いた官能基別有機炭素と無機物の空間分布―.
159. 農地表層土壌中の放射性セシウム濃度分布図作成のための緊急調査.
160. 放射性セシウム捕捉ポテンシャル(RIP)のセシウム濃度依存性.
161. 青森県十和田地域の草本植物群落と土壌化学性との関連.
162. 鉱物組成が異なる土壌の有機物集積作用をサブミクロンスケールから考える.
163. 生分解性マルチの分解速度が畑によって違う理由には土壌微生物とそれらが生産する酵素が関わっている.
164. 土壌生成因子(気候・母材)が土壌リンの存在形態へ及ぼす影響:キナバル山熱帯林における事例研究.