Language：English   Publishing type：Research paper (scientific journal)  

CO2 acts as an environmental signal that regulates stomatal movements. High CO2 concentrations reduce stomatal aperture, whereas low concentrations trigger stomatal opening. In contrast to our advanced understanding of light and drought stress responses in guard cells, the molecular mechanisms underlying stomatal CO2 sensing and signaling are largely unknown. Leaf temperature provides a convenient indicator of transpiration, and can be used to detect mutants with altered stomatal control. To identify genes that function in CO2 responses in guard cells, CO2-insensitive mutants were isolated through high-throughput leaf thermal imaging. The isolated mutants are categorized into three groups according to their phenotypes: (i) impaired in stomatal opening under low CO2 concentrations; (ii) impaired in stomatal closing under high CO2 concentrations; and (iii) impaired in stomatal development. Characterization of these mutants has begun to yield insights into the mechanisms of stomatal CO2 responses. In this review, we summarize the current status of the field and discuss future prospects.

DOI： 10.1093/pcp/pct145

Other Link： http://pcp.oxfordjournals.org/content/55/2/241

Language：English   Publishing type：Research paper (scientific journal)  

Stomata are highly specialized organs that consist of pairs of guard cells and regulate gas and water vapor exchange in plants [1-3]. Although early stages of guard cell differentiation have been described [4-10] and were interpreted in analogy to processes of cell type differentiation in animals [11], the downstream development of functional stomatal guard cells remains poorly understood. We have isolated an Arabidopsis mutant, stomatal carpenter 1 (scap1), that develops irregularly shaped guard cells and lacks the ability to control stomatal aperture, including CO2-induced stomatal closing and light-induced stomatal opening. SCAP1 was identified as a plant-specific Dof-type transcription factor expressed in maturing guard cells, but not in guard mother cells. SCAP1 regulates the expression of genes encoding key elements of stomatal functioning and morphogenesis, such as K(+) channel protein, MYB60 transcription factor, and pectin methylesterase. Consequently, ion homeostasis was disturbed in scap1 guard cells, and esterification of extracellular pectins was impaired so that the cell walls lining the pores did not mature normally. We conclude that SCAP1 regulates essential processes of stomatal guard cell maturation and functions as a key transcription factor regulating the final stages of guard cell differentiation.

DOI： 10.1093/pcp/pct145

Language：English   Publishing type：Research paper (scientific journal)  

In rice (Oryza sativa L.), leaf photosynthesis is known to be highly correlated with stomatal conductance; however, it remains unclear whether stomatal conductance dominantly limits the photosynthetic rate. SLAC1 is a stomatal anion channel protein controlling stomatal closure in response to environmental [CO2]. In order to examine stomatal limitations to photosynthesis, we isolated and characterized a SLAC1-deficient mutant of rice. A TILLING screen of NMU-derived mutant lines was conducted for the rice SLAC1 ortholog gene Os04g0674700, and four mutant lines containing mutations within the open reading frame were obtained. A second screen using an infrared thermography camera revealed that one of the mutants, named slac1, had a constitutive low-leaf-temperature phenotype. Measurement of leaf gas exchange showed that slac1 plants grown in the greenhouse had significantly higher stomatal conductance (gs), rates of photosynthesis (A) and ratios of internal [CO2] to ambient [CO2] (Ci/Ca) compared to wild-type plants, whereas there was no significant difference in the response of photosynthesis to internal [CO2] (A/Ci curves). These observations demonstrate that in well-watered conditions, stomatal conductance is a major determinant of photosynthetic rate in rice.

DOI： 10.1093/jxb/ers216

Other Link： http://jxb.oxfordjournals.org/cgi/content/abstract/ers216?ijkey=ymFhsQLo4LJxkUX&keytype=ref

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1093/pcp/pch133

Publishing type：Research paper (scientific journal)  

DOI： 10.1046/j.1365-313x.1997.12061241.x

Language：Japanese   Publisher：The Japan Scientists' Association  

DOI： 10.60233/jjsci.59.3_25

CiNii Research

Language：Japanese   Publisher：The Japan Scientists' Association  

作物の遺伝子操作は，従来の遺伝子組換え法に加えて，近年新たに開発されたゲノム編集技術が急速に広がり，多様化している．一方，それらの理解には専門知識を要するため，消費者側には食品としてそれらを受け入れることについて漠然とした不安があると考えられる．本稿では植物における遺伝子操作技術の現状を概説し，作物育種への適用についてその利点と問題点を整理する．

DOI： 10.60233/jjsci.59.3_13

CiNii Research

DOI： 10.1088/1741-4326/ace9e9

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Stomatal guard cells develop unique chloroplasts in land plant species. However, the developmental mechanisms and function of chloroplasts in guard cells remain unclear. In seed plants, chloroplast membrane lipids are synthesized via two pathways: the prokaryotic and eukaryotic pathways. Here we report the central contribution of endoplasmic reticulum (ER)-derived chloroplast lipids, which are synthesized through the eukaryotic lipid metabolic pathway, in the development of functional guard cell chloroplasts. We gained insight into this pathway by isolating and examining an Arabidopsis mutant, gles1 (green less stomata 1), which had achlorophyllous stomatal guard cells and impaired stomatal responses to CO₂ and light. The GLES1 gene encodes a small glycine-rich protein, which is a putative regulatory component of the trigalactosyldiacylglycerol (TGD) protein complex that mediates ER-to-chloroplast lipid transport via the eukaryotic pathway. Lipidomic analysis revealed that in the wild type, the prokaryotic pathway is dysfunctional, specifically in guard cells, whereas in gles1 guard cells, the eukaryotic pathway is also abrogated. CO₂-induced stomatal closing and activation of guard cell S-type anion channels that drive stomatal closure were disrupted in gles1 guard cells. In conclusion, the eukaryotic lipid pathway plays an essential role in the development of a sensing/ signaling machinery for CO₂ and light in guard cell chloroplasts.

DOI： 10.1073/pnas.1810458115

Language：English   Publishing type：Research paper (scientific journal)  

Background: The ppGpp signaling system is operative in plant chloroplasts and bacteria. Results: Chloroplast and cytosolic guanylate kinases (GKs) of plants are sensitive and insensitive to ppGpp, respectively, whereas bacterial GKs show diversity in ppGpp sensitivity. Conclusion: GTP biosynthesis in chloroplasts is controlled by ppGpp. Significance: Identification of the targets of ppGpp should provide insight into biological processes regulated by this nucleotide.

DOI： 10.1074/jbc.M113.534768

Language：English   Publishing type：Research paper (scientific journal)  

Stomata are highly specialized organs that consist of pairs of guard cells and regulate gas and water vapor exchange in plants [1-3]. Although early stages of guard cell differentiation have been described [4-10] and were interpreted in analogy to processes of cell type differentiation in animals [11], the downstream development of functional stomatal guard cells remains poorly understood. We have isolated an Arabidopsis mutant, stomatal carpenter 1 (scap1), that develops irregularly shaped guard cells and lacks the ability to control stomatal aperture, including CO₂-induced stomatal closing and light-induced stomatal opening. SCAP1 was identified as a plant-specific Dof-type transcription factor expressed in maturing guard cells, but not in guard mother cells. SCAP1 regulates the expression of genes encoding key elements of stomatal functioning and morphogenesis, such as K⁺ channel protein, MYB60 transcription factor, and pectin methylesterase. Consequently, ion homeostasis was disturbed in scap1 guard cells, and esterification of extracellular pectins was impaired so that the cell walls lining the pores did not mature normally. We conclude that SCAP1 regulates essential processes of stomatal guard cell maturation and functions as a key transcription factor regulating the final stages of guard cell differentiation.

DOI： 10.1016/j.cub.2013.02.001

Language：English   Publishing type：Research paper (scientific journal)  

The increased tolerance to NaCl 1 (ITN1) protein is a plasma membrane (PM)-localized protein involved in responses to NaCl stress in Arabidopsis. The predicted structure of ITN1 is composed of multiple transmembrane regions and an ankyrin-repeat domain that is known to mediate protein-protein interactions. To elucidate the molecular functions of ITN1, we searched for interacting partners using a yeast two-hybrid assay, and a nuclear-localized DNA-binding protein, RTV1, was identified as a candidate. Bimolecular fluorescence complementation analysis revealed that RTV1 interacted with ITN1 at the PM and nuclei in vivo. RTV1 tagged with red fluorescent protein localized to nuclei and ITN1 tagged with green fluorescent protein localized to PM; however, both proteins localized to both nuclei and the PM when co-expressed. These findings suggest that RTV1 and ITN1 regulate the subcellular localization of each other.

DOI： 10.1016/j.bbrc.2012.05.136

Language：English   Publishing type：Research paper (scientific journal)  

During early chloroplast differentiation, the regulation of the plastid genetic system including transcription and translation differs greatly from that in the mature chloroplast, suggesting the existence of a stage-dependent mechanism that regulates the chloroplast genetic system during this period. The virescent-1 (v ₁) mutant of rice (Oryza sativa) is temperature-conditional and develops chlorotic leaves under low-temperature conditions. We reported previously that leaf chlorosis in the v ₁ mutant is caused by blockage of the activation of the chloroplast genetic system during early leaf development. Here we identify the V ₁ gene, which encodes a chloroplast-localized protein NUS1. Accumulation of NUS1 specifically occurred in the pre-emerged immature leaves, and is enhanced by low-temperature treatment. The C-terminus of NUS1 shows structural similarity to the bacterial antitermination factor NusB, which is known to play roles in the regulation of ribosomal RNA transcription. The RNA-immunoprecipitation and gel mobility shift assays indicated that NUS1 binds to several regions of chloroplast RNA including the upstream leader region of the 16S rRNA precursor. In the leaves of the NUS1-deficient mutant, accumulation of chloroplast rRNA during early leaf development was impaired and chloroplast translation/transcription capacity was severely suppressed under low temperature. Our results suggest that NUS1 is involved in the regulation of chloroplast RNA metabolism and promotes the establishment of the plastid genetic system during early chloroplast development under cold stress conditions.

DOI： 10.1111/j.1365-313X.2011.04755.x

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s00425-011-1424-x

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Chloroplast biogenesis is most significant during the changes in cellular organization associated with leaf development in higher plants. To examine the physiological relationship between developing chloroplasts and host leaf cells during early leaf development, we investigated changes in the carbon and nitrogen contents in leaves at the P4 developmental stage of rice, during which leaf blade structure is established and early events of chloroplast differentiation occur. During the P4 stage, carbon content on a dry mass basis remained constant, whereas the nitrogen content decreased by 30%. Among carbohydrates, sucrose and starch accumulated to high levels early in the P4 stage, and glucose, fructose and cellulose degradation increased during the mid-to-late P4 stage. In the chloroplast-deficient leaves of the virescent-1 mutant of rice, however, the carbon and nitrogen contents, as well as the C/N ratio during the P4 stage, were largely unaffected. These observations suggest that developing rice leaves function as sink organs at the P4 stage, and that chloroplast biogenesis and carbon and nitrogen metabolism in the leaf cell is regulated independently at this stage.

DOI： 10.1007/s10265-009-0277-x

Language：English   Publishing type：Research paper (scientific journal)  

In rice, the developmental process in leaf formation can be divided into 7 stages (stages P0 to P6). We investigated chloroplast biogenesis and physiological changes in the developing leaves at the stage P4, during which leaf blade elongation and establishment of basic leaf blade structure occur. Chlorophyll content was negligible in the leaves early in the P4 stage and increased rapidly as they enters the late P4 phase. Chlorophyll fluorescence ratio (Fv/Fm) also increased markedly and the final value was comparable with that of mature leaves. Gene expression analysis showed that during the P4 stage, chloroplasts in the leaf cell undergo all three steps of differentiation: (i) plastid division and DNA replication (ii) establishment of plastid genetic system (iii) activation of photosynthetic apparatus. These observations suggest that the P4 is key in the development of a leaf, during which leaf rapidly differentiated both morphologically and physiologically, and that the P4 leaf is suitable for investigation of physiological relationships between chloroplast and leaf development.

DOI： 10.5511/plantbiotechnology.27.85

Language：English   Publishing type：Research paper (scientific journal)  

The virescent3 (v3) and stripe1 (st1) mutants in rice (Oryza sativa) produce chlorotic leaves in a growth stage-dependent manner under field conditions. They are temperature-conditional mutants that produce bleached leaves at a constant 20°C or 30°C but almost green leaves under diurnal 30°C/20°C conditions. Here, we show V3 and St1, which encode the large and small subunits of ribonucleotide reductase (RNR), RNRL1, and RNRS1, respectively. RNR regulates the rate of deoxyribonucleotide production for DNA synthesis and repair. RNRL1 and RNRS1 are highly expressed in the shoot base and in young leaves, and the expression of the genes that function in plastid transcription/translation and in photosynthesis is altered in v3 and st1 mutants, indicating that a threshold activity of RNR is required for chloroplast biogenesis in developing leaves. There are additional RNR homologs in rice, RNRL2 and RNRS2, and eukaryotic RNRs comprise α₂β ₂ heterodimers. In yeast, RNRL1 interacts with RNRS1 (RNRL1:RNRS1) and RNRL2:RNRS2, but no interaction occurs between other combinations of the large and small subunits. The interacting activities are RNRL1:RNRS1 > RNRL1:rnrs1(st1) > rnrl1(v3):RNRS1 > rnrl1(v3):rnrs1(st1), which correlate with the degree of chlorosis for each genotype. This suggests that missense mutations in rnrl1(v3) and rnrs1 (st1) attenuate the first αβ dimerization. Moreover, wild-type plants exposed to a low concentration of an RNR inhibitor, hydroxyurea, produce chlorotic leaves without growth retardation, reminiscent of v3 and st1 mutants. We thus propose that upon insufficient activity of RNR, plastid DNA synthesis is preferentially arrested to allow nuclear genome replication in developing leaves, leading to continuous plant growth.

DOI： 10.1104/pp.109.136648

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Linolenic acid (18:3) and its derivative jasmonic acid (JA) are important molecules in disease resistance in many dicotyledonous plants. We have previously used 18:3- and JA-deficient rice (F78Ri) to investigate the roles of fatty acids and their derivatives in resistance to the blast fungus Magnaporthe grisea [A. Yara, T. Yaeno, J.-L. Montillet, M. Hasegawa, S. Seo, K. Kusumi, K. Iba, Enhancement of disease resistance to Magnaporthe grisea in rice by accumulation of hydroxy linoleic acid, Biochem. Biophys. Res. Commun. 370 (2008) 344-347; A. Yara, T. Yaeno, M. Hasegawa, H. Seto, J.-L. Montillet, K. Kusumi, S. Seo, K. Iba, Disease resistance against Magnaporthe grisea is enhanced in transgenic rice with suppression of ω-3 fatty acid desaturases, Plant Cell Physiol. 48 (2007) 1263-1274]. However, because F78Ri plants are suppressed in the first step of the JA biosynthetic pathway, we could not confirm the specific contribution of JA to disease resistance. In this paper, we generated two JA-deficient rice lines (AOCRi and OPRRi) with suppressed expression of the genes encoding allene oxide cyclase (AOC) and 12-oxo-phytodienoic acid reductase (OPR), which catalyze late steps in the JA biosynthetic pathway. The levels of disease resistance in the AOCRi and OPRRi lines were equal to that in wild-type plants. Our data suggest that resistance to M. grisea is not dependent on JA synthesis.

DOI： 10.1016/j.bbrc.2008.08.157

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Linoleic acid (18:2) and linolenic acid (18:3) are sources for various oxidized metabolites called oxylipins, some of which inhibit growth of fungal pathogens. In a previous study, we found disease resistance to rice blast fungus Magnaporthe grisea enhanced in 18:2-accumulating transgenic rice (F78Ri) in which the conversion from 18:2 to 18:3 was suppressed. Here, we demonstrate that 18:2-derived hydroperoxides and hydroxides (HPODEs and HODEs, respectively) inhibit growth of M. grisea more strongly than their 18:3-derived counterparts. Furthermore, in F78Ri plants, the endogenous levels of HPODEs and HODEs increased significantly, compared with wild-type plants. These results suggest that the increased accumulation of antifungal oxylipins, such as HPODEs and HODEs, causes the enhancement of disease resistance against M. grisea.

DOI： 10.1016/j.bbrc.2008.03.083

Language：English   Publishing type：Research paper (scientific journal)  

Guanylate kinase (GK) is a critical enzyme in guanine nucleotide metabolism pathways, catalyzing the phosphorylation of (d)GMP to (d)GDP. Here we show that a novel gene, VIRESCENT 2 (V2), encodes a new type of GK (designated pt/mtGK) that is localized in plastids and mitochondria. We initially identified the V2 gene by positional cloning of the rice v2 mutant. The v2 mutant is temperature-sensitive and develops chlorotic leaves at restrictive temperatures. The v2 mutation causes inhibition of chloroplast differentiation; in particular, it disrupts the chloroplast translation machinery during early leaf development [Sugimoto et al. (2004)Plant Cell Physiol. 45, 985]. In the bacterial and animal species studied to date, GK is localized in the cytoplasm and participates in maintenance of the guanine nucleotide pools required for many fundamental cellular processes. Phenotypic analysis of rice seedlings with RNAi knockdown of cytosolic GK (designated cGK) showed that cGK is indispensable for the growth and development of plants, but not for chloroplast development. Thus, rice has two types of GK, as does Arabidopsis, suggesting that higher plants have two types of GK. Our results suggest that, of the two types of GK, only pt/mtGK is essential for chloroplast differentiation.

DOI： 10.1111/j.1365-313X.2007.03251.x

Language：English   Publishing type：Research paper (scientific journal)  

Linolenic acid (18:3) is the most abundant fatty acid in plant membrane lipids and is a source for various oxidized metabolites, called oxylipins. 18:3 and oxylipins play important roles in the induction of defense responses to pathogen infection and wound stress in Arabidopsis. However, in rice, endogenous roles for 18:3 and oxylipins in disease resistance have not been confirmed. We generated 18:3-deficient transgenic rice plants (F78Ri) with co-suppression of two ω-3 fatty acid desaturases, OsFAD7 and OsFAD8. that synthesize 18:3. The F78Ri plants showed enhanced resistance to the phytopathogenic fungus Magnaporthe grisea. A typical 18:3-derived oxylipin, jasmonic acid (JA), acts as a signaling molecule in defense responses to fungal infection in Arabidopsis. However, in F78Ri plants, the expression of JA-responsive pathogenesis-related genes, PBZ1 and PR1b, was induced after inoculation with M. grisea, although the JA-mediated wound response was suppressed. Furthermore, the application of JA methyl ester had no significant effect on the enhanced resistance in F78Ri plants. Taken together, our results indicate that, although suppression of fatty acid desaturases involves the concerted action of varied oxylipins via diverse metabolic pathways, 18:3 or 18:3-derived oxylipins, except for JA, may contribute to signaling on defense responses of rice to M. grisea infection.

DOI： 10.1093/pcp/pcm107

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Salicylic acid (SA) is known to be an essential component responsible for disease resistance in dicotyledonous plants. In rice, however, tissue contains extremely high endogenous levels of SA that do not increase after pathogen infection, suggesting that the SA has other major functions in healthy leaves. Although involvement of SA in oxidative-stress response is known in some dicotyledonous plants, antioxidative role of SA in rice is obscure. In this study, we examined the involvement of SA in the protection against oxidative stress in rice, using transgenic plants expressing the bacterial nahG gene that encodes salicylate hydroxylase, an SA-degrading enzyme. In SA-deficient NahG rice, the glutathione pool size was constitutively diminished as compared with control plants. NahG seedlings showed a delayed development phenotype, an increased susceptibility to oxidative stress and they developed light-induced lesions in their leaves without pathogen infection. Conversely, treatment with an activator of the SA-mediated defense-signaling pathway, probenazole, increased the glutathione pool size and suppressed lesion formation. These results suggest that in rice, SA has an important role in the response to high-light-induced oxidative stress, through its regulatory effects on glutathione homeostasis.

DOI： 10.1111/j.1399-3054.2006.00786.x

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Reactive oxygen intermediates (ROIs) play a pivotal role in the hypersensitive response (HR) in disease resistance. NADPH oxidase is a major source of ROI; however, the mechanisms of its regulation are unclear. Rice spl mutants spontaneously form lesions which resemble those occurring during the HR, suggesting that the mutations affect regulation of the HR. We found that spl2, spl7 and spl11 mutant cells accumulated increased amounts of H₂O ₂ in response to rice blast fungal elicitor. Increased accumulation of ROIs was suppressed by inhibition of NADPH oxidase in the spl cells, and was also observed in the ozone-exposed spl plants. These mutants have sufficient activities of ROI-scavenging enzymes compared with the wild type. In addition, spl7 mutant cells accumulated higher amounts of H₂O₂ when treated with calyculin A (CA), an inhibitor of protein phosphatase. Furthermore, spl2 mutant plants exhibited accelerated accumulation of H₂O ₂ and increased rates of cell death in response to wounding. These results suggest that the spl2, spl7 and spl11 mutants are defective in the regulation of NADPH oxidase, and the spl7 mutation may give rise to enhancement of the signaling pathway which protein dephosphorylation controls, while the spl2 mutation affects both the pathogen-induced and wound-induced signaling pathways.

DOI： 10.1093/pcp/pcj074

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1093/pcp/pch111

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Transgenic rice plants of Taiwanese japonica rice cultivar, Taichung 65, were obtained by cocultivating scutellum calli with an Agrobacterium tumefaciens strain, EHA101, that carried a binary vector harboring the luciferase (Luc) gene driven by the CaMV35S promoter. The transformation efficiency of Taichung 65 was similar to that obtained by the methods routinely used for a transformable cultivar, Notohikari. There was no correlation between the length of the culture period (21 to 30 days) and the transient transformation efficiency in Taichung 65 and in Notohikari. In the T₀- and T₁-generations, the transgenes were integrated and stably expressed, indicating that the transgene was inherited to the next generation. The copy number of integrated transgene varied from one to three in the T₁-transformants, which was confirmed by Southern blot analysis. Moreover, approximately 60% of the T₁-transformants of Taichung 65 showed the LUC-positive phenotype. These results suggest that, in addition to Notohikari, Taichung 65 is a practical, transformable cultivar.

DOI： 10.5511/plantbiotechnology.18.305

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

The rice zebra mutant TCM248 is a single recessive mutant. This mutant develops transverse-striped leaves with green and white sectors under alternate light/dark growth conditions. Mutants that were grown under a higher light intensity during the light period showed a more intense striped phenotype. The white tissues contained abnormal chloroplasts with few internal membrane structures, while the green tissues in the mutants contained normal chloroplasts. The white tissue contained only trace amounts of Chls and carotenoids, and mRNA accumulation of nuclear genes encoding chloroplast proteins (rbcS, cab) was strongly suppressed compared to that in the wild type plants. A series of growth condition shift experiments demonstrated that the mutant displayed the striped phenotype only if it was exposed to the alternate light/dark growth conditions during a limited stage of early leaf development. These data suggest that the zebra gene is involved in the acquisition of photoprotective capacity of the plants and that this gene functions at an early stage of chloroplast differentiation.

DOI： 10.1093/pcp/41.2.158

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1034/j.1399-3054.2000.108001019.x

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

ω-3 fatty acid desaturase is responsible for the production of α-linolenic acid, which is a major fatty acid constituent of membrane lipids in higher plants. In this study, the developmental regulation of the expression of two genes, TaFAD3 and TaFAD7, which respectively encode the microsome and plastid ω-3 fatty acid desaturases in wheat, was analyzed by in situ hybridization. The transcript of TaFAD3 was abundant in the apical meristems of both shoot and root, the leaf primordium, the leaf basal intercalary meristem, and the root vascular tissues. The level of TaFAD3 mRNA was also high in embryos developing after flowering. In mature embryos, however, it was low, whereas in germinating embryos it was once again high. These results suggest that the TaFAD3 mRNA is accumulated at a high level in cells that have an ability to proliferate. In contrast, the TaFAD7 mRNA level was very low in the shoot apical meristem, leaf primordium and leaf basal intercalary meristem, but a large accumulation of TaFAD7 mRNA was found in green tissues, suggesting that the accumulation of this mRNA is associated with chloroplast development. Although the spatial distribution patterns of TaFAD3 and TaFAD7 mRNAs clearly differed, the enhanced accumulation of the TaFAD3 and TaFAD7 mRNAs was linked with the active membrane biogenesis required for cell division and with the development of the thylakoid system in plastids, respectively.

DOI： 10.1093/oxfordjournals.pcp.a029402

Language：English   Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

DOI： 10.1023/A:1005726210977

Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

The rpoB gene for the β subunit of rice chloroplast RNA polymerase was found to be highly expressed in unexpanded immature levels that contained proplastids, indicating the specific expression of rpoB at early stage of chloroplast development. A putative transcription start site (tss) was identifield, but the 5′ upstream region of the tss had no sequences resembling typical -35 and -10 elements. A palindromic sequence and high AT-content were recognized.

DOI： 10.1093/oxfordjournals.pcp.a028936

Language：English   Publishing type：Research paper (scientific journal)  

Temperature-sensitive mutants of rice, designated virescent (v₁, v₂ and v₃), develop chlorophyll-deficient leaves at a restrictive temperature (20°C) but develop nearly normal green leaves at a permissive temperature (30°C). Analysis of the chlorophyll biosynthetic pathway in the virescent mutants indicated that the chlorophyll deficiency at the restrictive temperature was due to specific blockage of the C₅-pathway. Northern analysis suggested that the chlorophyll deficiency in the virescent mutants was caused by specific inhibition of the expression of chloroplast tRNA^Glu.

Language：English   Publishing type：Research paper (scientific journal)  

The endogenous circadian rhythm in a crassulacean acid metabolism (CAM) plant Graptopetalum paraguayense was investigated. Phosphoenolpyruvate carboxylase (PEP-C) takes two forms: the malate-sensitive day form and the malate-insensitive night form. We monitored the state of PEP-C by measuring the sensitivity to malate as a parameter of the circadian rhythm. We also measured vacuolar pH and malate concentration, and contents of oxaloacetate, pyruvate and phosphoenolpyruvate (PEP).A free-running circadian oscillation was observed under continuous dim light (5 klux) after 12 h/12 h light/dark cycles at 20°C. The period of the rhythm was about 20 h. Under continuous light (18 klux), the rhythm was less clear but the length of the period was not affected. On the other hand, the rhythms of the vacuolar pH and the malate concentration were evident under the continuous light, but were not clear under the continuous dim light. The rhythm disappeared in continuous darkness. The content of PEP changed simultaneously with the transformation of PEP-C during the normal day-night cycles and under the continuous light, but stayed at a low level under the continuous dim light. This indicated that the transformation of PEP-C was not sufficient to maintain the rhythm in the carbon metabolism.Shift of the timing of the start or end of the dark period prior to the continuous illumination shifted the phase of the PEP-C rhythm without changing the period length significantly. At 30°C, the rhythm of PEP-C was less clear, but the period length was not affected.These results suggest that the biological clock controls CO₂ uptake and day-night CAM cycle through regulation of PEP-C transformation.

Language：English   Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

The electrochemical potential difference for each dissociation state of malic acid across the tonoplast of leaf cells was examined in two CAM plants, Graptopetalum paraguayense and Kalanchoë daigremontiana. The concentration of malic acid in each dissociation state was estimated from an analysis of pH and concentrations of ionic species that included calcium, malate and isocitrate. The vacuoles contained 30-40 mM isocitrate and 50-70 mM calcium in G. paraguayense, and 20-30 mM isocitrate and 70-100 mM calcium in K. daigremontiana. For the calculation of the pattern of dissociation of malic acid, the formation of chelates of calcium with malate and isocitrate, which have different stability constants depending on the dissociation of the acids, were also taken into consideration. The vacuolar concentrations of the divalently dissociated form of malic acid (mal^2- were 4-7 mM and 1-3 mM in G. paraguayense and in K. daigremontiana, respectively. To obtain information about the cytoplasmic concentration of malate, the apparent inhibition constant for malate of phosphoenolpyruvate carboxylase was measured. It was about 330 μM in the dark period and 60 μM in the light period. Considering an inside-positive membrane potential, we conclude that mal^2- can be taken up passively into the vacuole during the dark period and can be released passively from the vacuole during the light period. Two types of channel (the "SV-type" channel and a novel "MU-type" channel) which we found recently in G. paraguayense [Iwasaki et al. (1992) Plant Physiol. 98: 1494] are probably involved in the uptake and the release of malate in the diurnal CAM rhythm. The existence of a large pH-buffering capacity due to isocitric acid in the vacuole allows the accumulation of a large amount of malic acid during the diurnal CAM rhythm.

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (international conference proceedings)  

Language：English   Publishing type：Research paper (scientific journal)  

Event date： 2022.6

Language：Japanese  

Venue：佐賀大学（佐賀）   Country：Japan  

土壌中に窒素栄養が豊富にある場合、地上部の生長が促進されるのに対して、根の生長は抑制される。このことは、土壌中の窒素を感知し、根の分裂組織の活性化を抑制するシステムの存在を示唆するが、その制御には不明な点が多い。近年、シロイヌナズナを含む複数の真核生物において、遺伝子間領域にshort open reading frame (sORF) と呼ばれる短い読み枠が多数見つかっているが、その中に形態形成や代謝経路の制御に関わる重要因子が含まれていることが報告されている。私たちはシロイヌナズナにおいて、高窒素環境下の側根形成抑制に関わると考えられるsORF、sorfc03を見いだした。sorfc03の過剰発現株の側根形成は野生株（Col-0）と同様に培地中の窒素濃度が3mM以上で抑制されるのに対し、ノックアウト株では側根形成が抑制されず、むしろ促進された。また、sorfc03の発現は培地中の窒素濃度に依存し正に誘導されたことから、sorfc03は高窒素環境下において側根形成を抑制する働きを持つと考えられる。

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Event date： 2022.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば   Country：Japan  

Arabidopsis short ORF, SORFC03 is involved in the repression of lateral root growth under high-nitrogen conditions

Event date： 2022.3

Language：Japanese  

Venue：つくば   Country：Japan  

土壌中に窒素栄養が豊富にある場合、地上部の生長が促進されるのに対して、根の生長は抑制される。このことは、土壌中の窒素を感知し、根の分裂組織の活性化を抑制するシステムの存在を示すが、その制御には不明な点が多い。近年、シロイヌナズナを含む複数の真核生物において、遺伝子間領域にshort open reading frame (sORF) と呼ばれる短い読み枠が多数見つかり、形態形成や代謝経路の制御に関わる重要因子が含まれることが報告されている。私たちはシロイヌナズナにおいて、高窒素環境下の側根形成抑制に関わると考えられるsORF、sorfc03を見いだした。sorfc03の過剰発現株の側根形成は野生株（Col-0）と同様に培地中の窒素濃度が3mM以上で抑制されるのに対し、ノックアウト株では側根形成が抑制されず、むしろ促進された。また、sorfc03の発現は培地中の窒素濃度に依存し正に誘導されたことから、sorfc03は高窒素環境下において側根形成を抑制する働きを持つと考えられる。sorfc03プロモーター::GUS形質転換体におけるGUS活性は側根原器や伸長中の側根では観察されず、地上部の維管束および主根基部で観察された。これらのことから、sorfc03は、高窒素環境下において地上部から根へのシグナル伝達を律速し、側根形成を抑制する因子である可能性がある。

researchmap

Event date： 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京都立大学（八王子）   Country：Japan  

sORFs associated with Nitrogen metabolism in Arabidopsis

Event date： 2021.6

Language：English   Presentation type：Oral presentation (general)  

Venue：Finland   Country：United States  

Nitrogen (N) is an important factor for the basis of metabolism for plant growth. While knowledge and understanding of N metabolism has improved considerably over the last several decades, most of the key factors involved in these processes still remain uncharacterized. Recently, short open reading frames (sORFs) were found in the known intergenic regions in eukaryotes. In Arabidopsis, about 8,000 sORFs have already been identified, however, most of them remain uncharacterized. In this study, we characterized one of these sORFs, sorfc03, which is suggested to be involved in the regulation of lateral root (LR) development associated with N metabolism.

Event date： 2021.6 - 2021.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：九州大学（福岡）   Country：Japan  

sORFs associated with Nitrogen metabolism in Arabidopsis

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：島根大学（松江）   Country：Japan  

sORFs associated with Nitrogen metabolism in Arabidopsis

Event date： 2020.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋大学（名古屋）   Country：Japan  

sORFs associated with Nitrogen metabolism in Arabidopsis

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東北大学（仙台）   Country：Japan  

sORFs associated with Nitrogen metabolism in Arabidopsis

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：広島国際会議場（広島）   Country：Japan  

sORFs associated with Nitrogen metabolism in Arabidopsis

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：Finland   Country：Finland  

Nitrogen (N) is an important factor for the basis of metabolism for plant growth. While knowledge and understanding of N metabolism has improved considerably over the last several decades, most of the key factors involved in these processes still remain uncharacterized. Recently, short open reading frames (sORFs) were found in the known intergenic regions in eukaryotes. In Arabidopsis, about 8,000 sORFs have already been identified, however, most of them remain uncharacterized. In this study, we characterized one of these sORFs, sorfc03, which is suggested to be involved in the regulation of lateral root (LR) development associated with N metabolism.

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：さいたま   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡   Country：Japan  

SLAC1 is a stomatal anion channel protein controlling stomatal closure in response to environmental [CO2]. SLAC1-deficient mutant of rice, slac1, exhibited significant increase in stomatal conductance (gs) with enhanced CO2 assimilation, showing that this channel plays a major role in stomatal closure in rice (1). In order to clarify contribution of the SLAC1 to stomatal regulation, we investigated changes in the stomatal conductance during the vegetative growth stage of rice, and compared them among the wild type (WT), slac1 and SLAC1-F461A, which expressed a dominant point mutation (F461A) causing constitutive stomatal closure (Fig. 1). All three lines had a maximum gs at the tillering stage. In the WT, gs value at this stage was over 2-fold higher than that at the latter heading stage. At the same stage, gs value was 50 % higher in slac1 and 70 % lower in SLAC1-F461A compared to the WT. In both slac1 and SLAC1-F461A, tillering rate and plant height are altered, and the grain yield was lower than wild type. These observations suggest that contribution of SLAC1 activity to stomatal closure is more important in young leaves during tillering stage in rice.
We are currently investigating effect of elevated CO2 on the growth and yields of slac1 and SLAC1-F461A. Optimization between CO2-uptake and respiration through stomatal regulation during rice growth will be discussed.

Event date： 2017.3 - 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：鹿児島   Country：Japan  

Rice cultivation mainly depends on soil water availability as well as on carbon fixation by photosynthesis. Therefore, optimal control of stomata, which regulates leaf respiration and CO2 absorption simultaneously, is vitally important for growth and development. SLAC1 is a stomatal S-type anion channel protein essential for stomatal closure. SLAC1-deficient mutant of rice, slac1, exhibited significant increase in stomatal conductance with enhanced CO2 assimilation, showing that this channel plays a major role in stomatal closure in rice. SLAC1 activity has been reported to be controlled through site specific phosphorylation in response to drought stress and enhanced CO2 concentration. In this study, we generated a series of dominant negative transgenic rice plants carrying a point mutation causing an amino acid substitutions in SLAC1, and investigated the responses of stomatal conductance and leaf temperature to changing CO2 concentration and humidity in these transgenic plants.

Event date： 2016.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：沖縄コンベンションセンター（沖縄）   Country：Japan  

sORFs associated with CO2 adaptation in Arabidopsis

Event date： 2016.8

Language：English   Presentation type：Oral presentation (general)  

Venue：MECC Maastricht, The Netherlands   Country：Netherlands  

Rice cultivation mainly depends on soil water availability as well as on carbon fixation by photosynthesis. Therefore, optimal control of stomata, which regulates leaf respiration and CO2 absorption simultaneously, is crucial for healthy growth. SLAC1 is a stomatal anion channel protein controlling stomatal closure in response to environmental [CO2]. SLAC1-deficient mutant of rice, slac1, exhibited significant increase in stomatal conductance (gs) with enhanced CO2 assimilation, showing that this channel plays a major role in stomatal closure in rice. In this study, in order to clarify contribution of the SLAC1 to stomatal regulation, we investigated changes in the stomatal conductance during the vegetative growth stage of rice, and compared them among the wild type (WT), slac1 and SLAC1-F461A, which expressed a dominant point mutation (F461A) causing constitutive stomatal closure.

Other Link： http://www.ps2016.com

Event date： 2016.3 - 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岩手、岩手大学   Country：Japan  

SLAC1 is a stomatal anion channel protein controlling stomatal closure. We previously reported that the SLAC1-deficient mutant of rice, slac1, had constitutively higher stomatal conductance compared to wild type. On the other hand, change in the stomatal conductance in response to some environmental cues, such as day-night cycle and change in the external [CO2], still remained in slac1, suggesting the possible existence of SLAC1-independent mechanism regulating stomatal closure. In this study, we examined transgenic rice, SLAC1-F461A, which expressed a point mutation causing an amino acid substitution (F461A) in SLAC1. Because side group of F461 is estimated to function as the channel gate, stomata in the SLAC1-F461A are expected to close constitutively. SLAC1-F461A plant had a high-leaf-temperature phenotype, and measurement of leaf transpiration showed that the stomatal conductance of young leaves of the SLAC1-F461A was about 70% lower than that of wild type. These indicate that in the SLAC1-F461A SLAC1 channels are always open and the stomata close constitutively. We will discuss the effect of the mutation on the growth and photosynthesis and contribution of SLAC1 to stomatal regulation during rice growth.

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：朱鷺メッセ (新潟)   Country：Japan  

植物にとってCO2は発生・成長に関わる重要な栄養源である。これまでCO2の取り込みと代謝に関わる多くの因子が同定されてきたが、それらの制御や組織間のシグナル伝達機構には不明な点が多い。近年、多くの真核生物で、遺伝子間領域にshort open reading frame (sORF) と呼ばれる、これまで遺伝子として同定されていない短いDNA配列が多数見つかり、その中には形態形成や代謝経路の制御に関わる重要因子が含まれていることがわかってきた。シロイヌナズナにおいては約8,000個のsORFが推定されており、機能解析が進められている。本研究では、これらのsORFのうち、過剰発現系統が高CO2 (800 ppm) でクロロシスや成長阻害を引き起こす15個を対象として、異なる組織と環境CO2濃度に応じた発現量の変化を調べた。MS培地上で、７日間および21日間生育させた植物体のロゼット葉と根からRNAを抽出し、qRT-PCR法で発現量を調べたところ、15個全てのsORFが発現しており、そのうち12個が地上部と比較して根で高い発現量を示した。また、それらのうち11個は高CO2環境下（1,000ppm）で発現が顕著に抑制された。以上の結果は、これらのsORFが、地上部と根の間の情報伝達を通じて、CO2環境の変化に応じた植物の代謝調節に関わっていることを示唆している。

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：朱鷺メッセ (新潟)   Country：Japan  

Short open reading frames associated with CO2 adaptation in Arabidopsis

Event date： 2015.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：朱鷺メッセ（新潟）   Country：Japan  

陰イオンチャネルタンパク質SLAC1は孔辺細胞に局在し、気孔閉鎖因子として機能する。イネにおいては、チャネル機能を欠失したslac1変異株では気孔コンダクタンス（gs）が上昇し、葉内へのCO2の吸収が増加することから、気孔閉鎖制御においてSLAC1が主要な役割を担っていると考えられる。本研究では気孔閉鎖におけるSLAC1の寄与を調べるため、slac1変異株に加え、SLAC1のチャネルゲートF461を置換したSLAC1-F461A株を用いて、分げつ期から出穂期にかけてのガス交換の変化を比較した。SLAC1-F461AではSLAC1チャネルが常に開いた状態となるため、気孔は閉鎖状態になると予想される。最上位葉のgsは、分げつ期初期において最も高く、幼穂形成期にかけて低下した。gsの値は測定期間を通じて、野生株と比較してslac1変異株では高く、SLAC1-F461Aで低くなり、その差は分げつ期前期で最も大きくなった。同時期における系統間のgsの差は、最も若い最上位葉で大きく、上位第２葉から第３葉にかけて小さくなった。これらの結果は、SLAC1の活性は分げつ期の若い葉で高く、気孔閉鎖制御に対する影響が大きいことを示している。

Event date： 2015.8

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京大（東京）   Country：Japan  

SLAC1は、細胞膜に存在するS型陰イオンチャネルタンパク質で、孔辺細胞に局在し気孔閉鎖因子として機能する。イネにおいては、チャネル機能を欠失したslac1変異株では気孔コンダクタンス（gs）が上昇し、葉内へのCO2の吸収が増加することから（Kusumi et al, 2011）、気孔閉鎖制御においてSLAC1が主要な役割を担っていると考えられる。しかし一方で、slac1変異株においても、gsの日周変化や生育に伴う増減が残ることから、SLAC1に依存しない気孔閉鎖機構が存在する可能性がある。本研究では気孔閉鎖制御におけるSLAC1の寄与を調べるため、slac1変異株に加え、SLAC1の推定チャネルゲートであるF461を置換したドミナントポジティブ株SLAC1-F461Aを用いて、分げつ期から出穂期にかけてのガス交換の変化を比較した。SLAC1-F461AではSLAC1チャネルが常に開いた状態となるため、気孔は閉鎖状態になると予想される。最上位葉のgsを測定したところ、分げつ期初期が最も高く、分げつ期後期から幼穂形成期にかけて低下した。gs の値は測定期間を通じて、野生株と比較してslac1変異株では高く、SLAC1-F461Aで低くなり、その差は分げつ期前期で最も大きくなった。分げつ期前期における系統間のgsの差は、最も若い最上位葉で大きく、上位第２葉から第３葉にかけて小さくなった。これらの結果は、分げつ期の若い葉でSLAC1の活性が高く、気孔閉鎖制御に対する影響が大きいことを示している。

Event date： 2015.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡 (福岡大学)   Country：Japan  

植物にとってCO2は発生・成長に関わる重要な栄養源である。これまでCO2の取り込みと代謝に関わる多くの因子が同定されてきたが、植物の成長や環境変化に応じたそれらの制御や組織間のシグナル伝達機構には不明な点が多く、未知の因子が多数残されていると考えられる。近年多くの真核生物で、遺伝子間領域にshort open reading frame (sORF) と呼ばれる、これまで遺伝子として同定されていない短いDNA配列が多数見つかり、その中には形態形成や代謝経路の制御に関わる重要因子が含まれていることがわかってきた。シロイヌナズナにおいては約8,000個のsORFが推定されており、解析が進んでいる (Hanada et al. 2013)。本研究では、高CO2 (800 ppm) でクロロシスを引き起こす表現型を指標に、シロイヌナズナのsORF過剰発現系統からスクリーニングした15系統を対象として、組織と生育環境に応じた発現の変化を調べ、その機能を推定した。

Event date： 2015.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京、東京農業大学   Country：Japan  

SLAC1 is a stomatal anion channel protein controlling stomatal closure. We previously reported that the SLAC1-deficient mutant of rice, slac1, had constitutively higher stomatal conductance compared to wild type. On the other hand, change in the stomatal conductance in response to some environmental cues, such as day-night cycle and change in the external [CO2], still remained in slac1, suggesting the possible existence of SLAC1-independent mechanism regulating stomatal closure. In this study, we examined transgenic rice, SLAC1-F461A, which expressed a point mutation causing an amino acid substitution (F461A) in SLAC1. Because side group of F461 is estimated to function as the channel gate, stomata in the SLAC1-F461A are expected to close constitutively. SLAC1-F461A plant had a high-leaf-temperature phenotype, and measurement of leaf transpiration showed that the stomatal conductance of young leaves of the SLAC1-F461A was about 70% lower than that of wild type. These indicate that in the SLAC1-F461A SLAC1 channels are always open and the stomata close constitutively. We will discuss the effect of the mutation on the growth and photosynthesis and contribution of SLAC1 to stomatal regulation during rice growth.

Event date： 2014.10

Language：English   Presentation type：Oral presentation (general)  

Venue：定山渓、北海道   Country：Japan  

Chloroplast biogenesis is most significant during the changes in cellular organization associated with leaf development in higher plants. During early leaf development, the structure and function of the chloroplasts differ greatly from those in a mature leaf, suggesting the existence of a stage-specific mechanism regulating chloroplast development during this period. We have analyzed genes involved specifically in early chloroplast biogenesis by using low temperature-conditional mutants of rice (Oryza sativa). These genes encode factors involved in chloroplast rRNA regulation (NUS1), and nucleotide metabolism in mitochondria, chloroplasts and cytosol (V2, V3, ST1). These are all preferentially expressed in the early leaf developmental stage P4, and depleting them causes altered chloroplast transcription and translation, and ultimately leaf chlorosis. Accordingly, regulation of cellular nucleotide pools and nucleotide metabolism is likely to be involved in the chloroplast biogenesis under low temperatures at this stage. Current understanding of these factors and organization of them during early leaf development will be discussed.

Event date： 2014.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：沖縄(琉球大学)   Country：Japan  

SLAC1は、高等植物の細胞膜陰イオンチャネルタンパク質で、孔辺細胞に局在し気孔閉鎖因子として機能する。イネのSLAC1機能欠失株slac1においては、野生株と比較し気孔コンダクタンスが最大約2.5倍上昇し、それに伴いCO2の取込量が1.5倍程度増加し、葉面温度が1〜2℃低下する。このことは、SLAC1がイネにおいても気孔閉鎖因子として機能することを示している。一方、slac1変異株においても気孔コンダクタンスは日周や生育段階に応じて増減する事から、SLAC1に依存しない気孔閉鎖機構の存在が示唆される。本研究では、SLAC1遺伝子の発現と気孔コンダクタンスの変化を、解放圃場および温室で栽培したイネを用いて、幼苗期から登熟期までの生育期間を通じて調べた。生育段階と葉位に応じた変化をslac1変異株と野生株の間で比較することにより、気孔閉鎖におけるSLAC1の寄与を検討した。

Event date： 2014.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：沖縄(琉球大学)   Country：Japan  

NUS1はイネから単離された葉緑体RNA結合蛋白質で、未抽出の若い葉で一過的に蓄積し成熟葉では消失する。これまでの研究から、NUS1は低温誘導性を持ち、葉緑体未成熟rRNAと結合してその成熟化をコントロールしていると考えられる。本研究ではNUS1の機能の普遍性を検討するため双子葉植物であるシロイヌナズナにおけるNUS1の機能を調べた。成長過程におけるNUS1の蓄積を段階的に調べたところ、発芽直後の幼根伸長時にはすでにNUS1の蓄積が見られ、子葉展開直後に最も多く蓄積し緑化と共に消失した。一方、低温生育条件下（10℃）ではNUS1の蓄積量は増加し、子葉が緑化し本葉が抽出した後も蓄積し続けた。一方、NUS1を機能欠失した植物は低温生育条件下で子葉の白化が見られた。さらに、in vitro RNA結合実験により、NUS1は葉緑体未成熟rRNAに結合することがわかった。これらの結果から、NUS1の機能は高等植物間で保存されており、葉の発生初期における低温ストレス下の葉緑体遺伝子発現装置のメンテナンスに必須の因子であると考えられる。

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山、富山大学   Country：Japan  

SLAC1 is a stomatal anion channel protein controlling stomatal closure in response to environmental [CO2]. Our previous study showed that the SLAC1-deficient mutant of rice, slac1, had higher stomatal conductance, higher rates of photosynthesis and lower leaf temperature compared to the wild-type plants, revealing that SLAC1 was involved in stomatal closure in rice, as was observed in Arabidopsis. On the other hand, change in the stomatal conductance in response to day-night cycle as well as to the external [CO2] still remained in the slac1 mutant, suggesting the possible existence of SLAC1-independent mechanism regulating stomatal closure. To estimate the contribution of SLAC1 to stomatal closure, we examined the effect of different developmental stage and different leaf position on SLAC1 gene expression and the stomatal conductance in the slac1 mutant and wild-type plants. Our data suggest the tissue-specificity and age-dependency of SLAC1 function in the stomatal closure in rice.

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：岡山   Country：Japan  

In rice (Oryza sativa L.), leaf photosynthesis is known to be highly correlated with stomatal conductance. Hower, it remains unclear whether stomatal conductance dominantly limits the photosynthetic rate. SLAC1 is a stomatal anion channel protein controlling stomatal closure in response to environmental [CO2]. In order to examine stomatal limitations to photosynthesis, we isolated and characterized a SLAC1-deficient mutant of rice, slac1. The slac1 plant had a constitutive low-leaf-temperature phenotype. Measurement of leaf gas exchange showed that slac1 plants had significantly higher stomatal conductance (gs), rates of photosynthesis (A) and ratios of internal [CO2] to ambient [CO2] (Ci/Ca) compared to wild-type plants, whereas there was no significant difference in the response of photosynthesis to internal [CO2] (A/Ci curves). These observations demonstrate that stomatal conductance is a major determinant of photosynthetic rate in rice.

Event date： 2012.12

Presentation type：Oral presentation (invited, special)  

Venue：福岡（九州大学）   Country：Japan  

Event date： 2012.3

Presentation type：Oral presentation (general)  

Venue：京都産業大学（京都）   Country：Japan  

葉緑体の転写・翻訳装置は、葉緑体分化初期の短期間に集中的に発現する。このプロセスは低温ストレスの影響を受けやすく、これまでイネやシロイヌナズナにおいて葉緑体の転写・翻訳装置の発現が阻害された低温感受性のクロロシス変異体が多数報告されている。このことは同時期において転写・翻訳装置の発現を低温ストレスから防御するためのメカニズムが存在する事を示すが、その実体は不明である。NUS1はイネから単離された約30kDaの色素体タンパク質である。NUS1はイネの未抽出葉で多量に蓄積するが、成熟葉では消失する。また24時間の低温処理（20°C）で蓄積が誘導され、高温処理（30°C）で抑制される。NUS1はＣ末端側の構造が、バクテリアのrRNA発現制御因子NusBのRNA結合ドメインと似ており、RNA-IP法およびゲルシフト解析により未成熟16S rRNAの5'リーダー配列と結合することが分かった。

Event date： 2011.9

Presentation type：Oral presentation (general)  

Venue：東京大学（東京）   Country：Japan  

イネにおいては、様々な条件で気孔開度と光合成速度の間に高い正の相関が見られる。しかしCO2の取り込みに際しては気孔抵抗と並んで葉肉抵抗も大きく、気孔が律速要因となっているかは明らかではなかった。SLAC1は、シロイヌナズナから単離されたジカルボン酸輸送タンパク質で、孔辺細胞に局在し気孔閉鎖因子として機能する。私たちはTILIING法によりイネのSLAC1オルソログ遺伝子に変異を持つ突然変異株osslac1-1を単離し、気孔と光合成への影響を調べた。osslac1-1の葉では、野生株と比較して気孔コンダクタンスが高くなり、葉面温度が低下することからSLAC1の機能抑制により気孔が開口していると考えられる。自然光条件下で光合成速度を測定したところ、osslac1-1においては野生株と比較して40%〜60%程度高くなることがわかった。これらの結果は、イネにおいては気孔が光合成の律速要因となっており、気孔を開くことでより多くのCO2を取り込めることを示す。

Event date： 2011.3 - 2011.5

Presentation type：Oral presentation (general)  

Venue：東北大学、仙台   Country：Japan  

Characterization of SLAC1-deficient mutant of rice

Event date： 2010.9

Presentation type：Oral presentation (general)  

Venue：中部大学、名古屋   Country：Japan  

Event date： 2008.11

Presentation type：Oral presentation (general)  

Venue：Jeju   Country：Korea, Republic of  

Regulation of chloroplast biogenesis during early stages of leaf development in rice.

Other Link： http://www.isrfg2008.com

Event date： 2020.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：大阪   Country：Japan  

Event date： 2019.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2019.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：名古屋   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：さいたま   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：札幌   Country：Japan  

Event date： 2018.6

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北海道大学（札幌）   Country：Japan  

Event date： 2018.6

Language：Japanese  

Venue：宮崎   Country：Japan  

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山、富山大学   Country：Japan  

The guard cell chloroplast is the site of perception of blue light and photosynthetically active radiation, and of at least one of the mechanisms for sensing CO2 in the guard cell. The guard cell chloroplast has been the focus of intense controversy over its capacity for light sensing and photosynthetic carbon fixation, and the osmoregulatory mechanisms mediating stomatal movements. In this study, gles1 (green less stomata 1), an Arabidopsis mutant with non-chlorophyllous stomata, was isolated.

Event date： 2014.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：富山、富山大学   Country：Japan  

Event date： 2013.3

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：つくば市、農業環境技術研究所   Country：Japan  

Event date： 2012.5

Presentation type：Oral presentation (general)  

Venue：佐賀(佐賀大学)   Country：Japan  

Event date： 2011.10

Presentation type：Oral presentation (general)  

Venue：熊本大学（熊本）   Country：Japan  

植物の葉緑体は独自のゲノムと遺伝子発現装置を持つ、半自立的な細胞内オルガネラである。光合成装置関連の遺伝子発現が活発な成熟葉の葉緑体と異なり、発生初期の葉の葉緑体ではRNAポリメラーゼ、rRNA、リボソームタンパク質など、転写・翻訳装置の遺伝子が集中的に発現する。このことは、この時期に特異的に機能する葉緑体分化制御メカニズムが存在することを示唆するが、その詳細はよく分かっていない。NUS1は最近イネから単離された葉緑体タンパク質で、葉の発生初期に一過的に発現し、成熟葉では消失する。また、NUS1はＣ末端側にバクテリアの転写調節因子NusBのRNA認識・結合部位と似た構造の領域を持ち、ゲルシフト解析から葉緑体の未成熟16S rRNAの5'リーダー部に結合することが分かった。NUS1を欠失したイネおよびシロイヌナズナは共に葉緑体rRNAの成熟化が損なわれ、その後の葉緑体分化がストップし葉がクロロシス（白化）を引き起こす。このことからNUS1は葉緑体rRNAの成熟化を介して、分化初期の葉緑体遺伝子発現を制御していると考えられる。

Event date： 2011.9

Venue：九州大学、福岡   Country：Japan  

Event date： 2010.9

Presentation type：Oral presentation (general)  

Venue：中部大学、名古屋   Country：Japan  

Event date： 2010.5

Presentation type：Oral presentation (general)  

Venue：九州大学   Country：Japan  

Event date： 2010.5

Presentation type：Oral presentation (general)  

Venue：長崎大学、長崎   Country：Japan  

Event date： 2010.3

Presentation type：Oral presentation (general)  

Venue：熊本大学   Country：Japan  

Event date： 2009.5

Presentation type：Oral presentation (general)  

Venue：宮崎大学   Country：Japan  

Event date： 2008.10

Venue：大阪大学   Country：Japan  

Event date： 2008.7

Presentation type：Oral presentation (general)  

Venue：九州大学   Country：Japan  

Event date： 2008.3

Venue：北海道大学（札幌市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：東北大学（仙台市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：宮崎大学（宮崎市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：福岡ドーム（福岡市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：椙山女学園大学（名古屋市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：東京大学（東京都文京区）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：長崎大学（長崎市）   Country：Japan  

Venue：Quebec   Country：Canada  

Venue：Quebec   Country：Canada  

Presentation type：Oral presentation (general)  

Venue：静岡大学（静岡市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州産業大学（福岡市）   Country：Japan  

Venue：九州産業大学（福岡市）   Country：Japan  

Venue：九州産業大学（福岡市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：佐賀大学（佐賀市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：岩手生物工学研究センター（北上市）   Country：Japan  

Venue：東京大学（東京都目黒区）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：大阪大学蛋白質研究所（吹田市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：岡山大学（岡山市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州大学（福岡市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：近畿大学（大阪市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：近畿大学（大阪市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：熊本大学（熊本市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：熊本大学（熊本市）   Country：Japan  

Venue：Barcelona   Country：Spain  

Presentation type：Oral presentation (general)  

Venue：九州大学（福岡市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：札幌コンベンションセンター（札幌市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：東京都立大学（八王子市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：東京都立大学（八王子市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：東京都立大学（八王子市）   Country：Japan  

Venue：東京都立大学（八王子市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州大学（福岡市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州大学（福岡市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：大学セミナーハウス（八王子市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州大学（福岡市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：日本大学湘南キャンパス（藤沢市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：大阪大学（吹田市）   Country：Japan  

Venue：Centennial hall lyushu university school of medicine（福岡市）   Country：Japan  

Venue：Centennial hall lyushu university school of medicine（福岡市）   Country：Japan  

Venue：神戸ポートアイランド（神戸市）   Country：Japan  

Venue：新潟コンベンションセンター朱鷺メッセ（新潟市）   Country：Japan  

Venue：新潟コンベンションセンター朱鷺メッセ（新潟市）   Country：Japan  

Venue：新潟コンベンションセンター朱鷺メッセ（新潟市）   Country：Japan  

Venue：新潟コンベンションセンター朱鷺メッセ（新潟市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：琉球大学（沖縄県西原町）   Country：Japan  

Venue：神戸国際会議場   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：ヤフードーム（福岡市）   Country：Japan  

Venue：筑波大学（つくば市）   Country：Japan  

Venue：筑波大学（つくば市）   Country：Japan  

Venue：筑波大学（つくば市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：筑波大学（つくば市）   Country：Japan  

Venue：九州大学国際ホール（福岡市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：鹿児島大学（鹿児島市）   Country：Japan  

Venue：Kyoto International Conference Hall（Kyoto）   Country：Japan  

Venue：Okazaki Conference Center（Aichi）   Country：Japan  

Venue：Magdalen College, Oxford   Country：United Kingdom  

Venue：宮崎県シーガイア   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：愛媛大学（松山市）   Country：Japan  

Venue：愛媛大学（松山市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：愛媛大学（松山市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：九州産業大学（福岡市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：北海道大学（札幌市）   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：大分大学   Country：Japan  

Presentation type：Oral presentation (general)  

Venue：大分大学   Country：Japan  

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：3

Type：Competition, symposium, etc. 

Number of participants：120

Type：Competition, symposium, etc. 

Number of participants：120

Type：Competition, symposium, etc. 

Number of participants：800

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：2

Type：Competition, symposium, etc. 

Number of participants：120

Type：Competition, symposium, etc. 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：3

Type：Competition, symposium, etc. 

Number of participants：120

Type：Competition, symposium, etc. 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：4

Type：Competition, symposium, etc. 

Number of participants：120

Type：Competition, symposium, etc. 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：3

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：4

Type：Competition, symposium, etc. 

Number of participants：150

Type：Competition, symposium, etc. 

Number of participants：120

Type：Competition, symposium, etc. 

Number of participants：120

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：150

Type：Competition, symposium, etc. 

Number of participants：50

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：150

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：150

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：150

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：150

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：200

Type：Competition, symposium, etc. 

Number of participants：150

Type：Competition, symposium, etc. 

Number of participants：150

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Number of participants：150

Type：Competition, symposium, etc. 

Number of participants：150

Type：Competition, symposium, etc. 

Number of participants：200

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Seminar, workshop

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福岡市 名島校区への不要機器譲渡事業
PTA活動を通じて、九州大学から福岡市立名島小学校への不要機器（顕微鏡30台）の譲渡事業を行った。

Type：Other

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Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Research consultation

九州大学から福岡市立名島小学校への不要機器（顕微鏡30台）の譲渡作業を行った。これらの顕微鏡は、20年程度前まで、理学部生物学科で実習用として使用されてきたものだが、単眼かつ光源装置が無く、新しい顕微鏡の購入と共に使用されなくなっていた。今回、伊都キャンパスへの移転作業の過程で廃棄されることになったものを再整備（50台程度の中から、使用可能な部品を組み合わせた）し、譲渡した。小学校に配備されている顕微鏡は今回のものより機能や頑丈さが劣る上、５人に１人程度の台数しか無かったものが、充分な台数の確保につながる。

Type：Research consultation

九州大学から福岡市立名島小学校への不要機器（顕微鏡30台）の譲渡作業を行った。これらの顕微鏡は、20年程度前まで、理学部生物学科で実習用として使用されてきたものだが、単眼かつ光源装置が無く、新しい顕微鏡の購入と共に使用されなくなっていた。今回、伊都キャンパスへの移転作業の過程で廃棄されることになったものを再整備（50台程度の中から、使用可能な部品を組み合わせた）し、譲渡した。小学校に配備されている顕微鏡は今回のものより機能や頑丈さが劣る上、５人に１人程度の台数しか無かったものが、充分な台数の確保につながる。

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Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Type：Seminar, workshop

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Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Other

Type：Other

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