Kyushu University [Toshihiko EGUCHI (Associate Professor) Environmental Control Center for Experimental Biology, ]

Toshihiko EGUCHI

Last modified date：2024.04.01

Associate Professor / Environmental Control Center for Experimental Biology

Papers

1.	Toshihiko EGUCHI, Kenshin Igarashi, Haruna Sato, Satoshi YOSHIDA and Ken MATSUOKA, Drying method affects sugar content in the corm of the medicinal plant Pinellia ternata Breit. , Environmental Control in Biology, DOI: 10.2525/ecb.61.55, 61, 3, 55-57, 2023.07, We compared the sugar, dry matter, and effective ingredient levels of the dried corms of the medicinal plant Pinellia ternata Breit. obtained by two drying methods: natural and freeze drying. The sucrose, glucose, and fructose levels were significantly higher in the naturally dried corm than those in the freeze-dried corm. Dry matter content was also significantly higher in naturally dried corm than in freeze-dried corm. There was no significant difference between the levels of the effective ingredients in the corms obtained using the different drying methods. The two drying methods, natural and freeze drying, affected the sugar content of P. ternata corm..
2.	Hiromi Nakai , Daisuke Yasutake , Kota Hidaka, Toshihiko Eguchi ,Gaku Yokoyama, Tomoyoshi Hirota, Starch serves as an overflow product in the regulation of carbon allocation in strawberry leaves in response to photosynthetic activity, Plant Growth Regulation, https://doi.org/10.1007/s10725-023-01042-9, 101, 875-882, 2023.07, The carbon allocation in source leaves between sucrose and starch is an important mechanism that affects plant productiv- ity. We previously found that strawberry plants accumulate starch in response to excess carbon supply from photosynthesis compared with translocation and sucrose storage capacity in source leaves. However, because these data were acquired from three separate cultivation seasons in field conditions, seasonal impacts could not be ruled out. Therefore, herein, we aimed to investigate the role of starch in carbon allocation in strawberry leaves and to explore whether the relationship between sucrose and starch reported in our previous study is an inherent characteristic that is independent of seasonal variations. To prevent seasonal influences, carbohydrate dynamics in strawberry leaves were studied under controlled environmental conditions with high (High) and low (Low) photosynthetic activity. During the day, both sucrose and starch concentrations increased in the High treatment, but starch concentration increased only marginally in the Low treatment. Furthermore, starch production was enhanced in the High treatment when sucrose concentration exceeded 150 mmol C m−2. Consistent with previous findings, the current findings indicated that photosynthetically fixed carbon is initially allo- cated to sucrose; however, when photosynthetic activity increases and leaf sucrose concentration exceeds its storage capac- ity, the excess carbon is then allocated to starch. This study provides strong evidence that, regardless of season, starch serves as an overflow product with sucrose storage capacity as a threshold during carbon allocation in strawberry leaves..
3.	Toshihiko EGUCHI, Hiroyuki TANAKA, Mayuki SAGAWA, Satoshi YOSHIDA and Ken MATSUOKA, Time-course Pattern of Growth of the Medicinal Plant Pinellia ternata Breit. Grown under Controlled Environments , Environmental Control in Biology, DOI: 10.2525/ecb.60.191, 60, 4, 191-194, 2022.10, To obtain the typical growth pattern of the medicinal plant Pinellia ternata Breit., we investigated the growth of plants grown under constantly controlled environments (air temperature: 25℃, air humidity: 70%RH, day length: 12h, light intensity: 220μmol photon m-2 s-1 (PPFD) ). The growth pattern was comparable with other plant growth patterns grown under different environmental conditions. Leaf number, leaf area, and corm weight of the plants increased over time, while dry matter content in the corm maintained at approximately 35% during cultivation. Cormlets born on the corm increased linearly during cultivation, and the weight increased significantly after 11 weeks of cultivation. The content of araban, the effective ingredient of the corm, increased linearly until 11 weeks of cultivation, after which, the content appeared to level off. Thus, we obtained the typical growth pattern of the P. ternata, which is useful for evaluating the environmental effects on the plant productivity..
4.	Toshihiko EGUCHI, Hiroyuki TANAKA, Satoshi YOSHIDA and Ken MATSUOKA, Effects of Nutrient Solution Electrical Conductivity and pH on the Productivity of the Medicinal Plant Pinellia ternata Breit., Environmental Control in Biology, DOI: 10.2525/ecb.60.149, 60, 2, 149-151, 2022.04, Medicinal plants (Pinellia ternata Breit.) were cultivated under four nutrient solution conditions, namely a pH of 4 and electrical conductivity (EC) of 2.2 mS cm-1, pH of 4 and EC of 1.2 mS cm -1, pH of 6 and EC of 2.2 mS cm-1, and pH of 6 and EC of 1.2 mS cm-1. Plants were grown for 15 weeks in phytotron glass rooms controlled at an air temperature of 25 °C and a relative humidity of 70 %. The leaf number per plant was measured every week, the leaf chlorophyll content (SPAD) was measured at 100 d after planting, and the corm yield and the effective ingredient, namely araban, content in the corm were evaluated after 15 weeks of cultivation. No clear effects of the nutrient solution EC and pH on the corm growth, the corm quality, and leaf chlorophyll content were not observed in this experiment. The EC and pH of the nutrient solution will not affect the productivity of the P. ternate in the ranges of EC 1.2 – 2.2 mS cm-1 and pH 4 – 6, respectively..
5.	Hiromi Nakai , Daisuke Yasutake , Kensuke Kimura , Kengo I , Kota Hidaka , Toshihiko Eguchi, Tomoyoshi Hirota, Takashi Okayasu, Yukio Ozaki, Masaharu Kitano, Dynamics of carbon export from leaves as translocation affected by the coordination of carbohydrate availability in field strawberry, https://doi.org/10.1016/j.envexpbot.2022.104806, 196, 2022.01, Carbon export from leaves as translocation is a result of plant coordination of leaf carbohydrate availability. Carbohydrate availability coordination is actively studied in model plants (Arabidopsis) under regulated condi- tions and can be optimized to increase productivity. However, in horticultural crops grown under field condi- tions, carbon export dynamics and coordination are poorly understood. The objective of this study was to analyze the dynamics of carbon export from leaves and the effects of carbohydrate availability coordination on these dynamics in strawberry grown under field conditions. Through three different day/night cycles, we measured leaf carbohydrate concentrations and photosynthetic rates and evaluated the dynamics of carbon export based on the leaf carbon balance. During the daytime, when carbon resources are almost entirely supplied by photosyn- thesis, strawberry leaves stored sucrose and starch. Starch synthesis was remarkable when sucrose concentration exceeded 150 mmol m− 2, and the carbon export rate tended to increase. In the nighttime, when carbon resources are supplied by leaf sucrose and starch stored during the daytime, the starch concentrations decreased linearly and the carbon export rate was lower than the daytime level. These results indicate that in the daytime, the coordination of leaf carbohydrate availability for starch storage and carbon export was affected by leaf sucrose concentration, whereas, at night, it was regulated by leaf carbon storage levels at dusk rather than sucrose concentration. Thus, this study elucidates the basis of carbon export dynamics in strawberry leaves under field conditions, advancing our understanding of the role of leaf carbohydrates in translocation..
6.	Toshihiko EGUCHI, Hiroyuki TANAKA, Daichi Moriuchi, Satoshi YOSHIDA and Ken MATSUOKA, Temperature Effects on the Photosynthesis by the Medicinal Plant Pinellia ternata Breit., Environmental Control in Biology, DOI: 10.2525/ecb.58.49, 58, 2, 49-50, 2020.04, We investigated the effect of air temperature on the growth of the medicinal plant Pinellia ternata Breit. collected from the four prefectures, Fukushima, Kyoto, Nagasaki, and Okinawa prefectures. Plants were grown for 15 weeks in phytotrons controlled at air temperatures of 20, 25, and 30 ̊C. In the Kyoto lines, the highest corm yield was observed at 25 ̊C, whereas the corm yields in Fukushima, Nagasaki, and Okinawa lines did not differ significantly with respect to yield among the three growth temperature conditions. Therefore, in this study, the temperature effects on the photosynthesis by P. ternata collected from the three prefectures of Kyoto, Nagasaki, and Okinawa were investigated. Obvious effects of air temperatures were not observed in the plant photosynthesis for all regions. Thus, air temperature does not affect the yield through the photosynthesis in the P. ternata..
7.	Toshihiko EGUCHI, Hiroyuki TANAKA, Satoshi YOSHIDA and Ken MATSUOKA, Temperature Effects on the Yield and Quality of the Medicinal Plant Pinellia ternata Breit., Environmental Control in Biology, DOI: 10.2525/ecb.57.83, 57, 3, 83-85, 2019.07, The medicinal plant Pinellia ternata Breit., which is a non-domesticated plant, is widely distributed in Japan. However, the crude drug made from the plant corm is not currently produced in Japan. We investigated the influences of air temperature on the growth of P. ternata collected from 2 regions, the Kyoto and Nagasaki prefectures, for both of summer and winter seasons. The temperature effects on the effective ingredient contents in the corms were also investigated. At Kyushu University, plants were grown for 15 weeks in phytotron glass rooms controlled at air temperatures of 20, 25, or 30°C. The corm yields and effective ingredient content in the winter cultivation were poorer than those in the summer, because the cumulative solar radiation during the winter cultivation period was almost half of that in the summer. In the Kyoto lines, the highest corm yield was obtained at 25℃ in the summer cultivation, while the Nagasaki lines did not show significant differences with respect to yield among the three growth temperature conditions. The effective ingredient contents in the corm did not differ significantly among the three temperature conditions for both lines, although the amount of effective ingredient in the Kyoto lines were significantly higher than those of Nagasaki in summer cultivation..
8.	T. K. Son, T. Eguchi, Y. Shoyama, H. Tanaka, ELISA for the Detection of Marker Compound for Crop Fertilizer Use of Various Medicinal Crop Extracts using Bacterium, Journal of the Faculty of Agriculture, Kyushu University, 64, 1, 27-32, 2019.02, This study builds an easy and quick method of analysing the active ingredients in bio–fertilizers to ensure the uniformity of materials in bio–fertilizers that are made using ingredients that are cruder herbal materials or remnants after the primary medicinal crops are used as herbal materials. An ELISA was cre- ated using MAb, and it can substitute for HPLC in the analysis of saikosaponin a (SSa), ginsenoside (G– Rb1) and ginsenoside (G–Rg1), which are active ingredients of ginseng, and the ELISA can be used for var- ious ginseng plants grown as typical medicinal crops. The concentration measurement ranges of G–Rb1, G–Rg1, and SSa are 12.5~250 ng/mL, 0.5~12.5 μg/mL, and 0.26~1.5 μg/mL, respectively..
9.	Eguchi, T., Satoshi YOSHIDA, Time-course Pattern of Electrolyte Leakage from Tuberous Roots of Sweetpotato (Ipomoea batatas (L.) Lam.) after Short-term High Temperature, Environmental Control in Biology, http://doi.org/10.2525/ecb.54.183, 54, 4, 183-185, 2016.10, We investigated the time-course pattern of electrolyte leakage from the root flesh of growing tuberous roots of two sweetpotato cultivars, Koganesengan and Narutokintoki, after exposing them to high temperature for short duration. For both cultivars, the electrolyte leakage after 1 h of treatment was significantly higher than that at 24 h after treatment. This pattern was similar to the pattern observed following instantaneous flooding treatment previously reported by us. Electrolyte leakage from plant cells is an indicator of cellular responses to various stress factors. Similar stress, therefore, might be caused in heated and flooded tuberous roots..
10.	Eguchi, T., Ito, Y., Satoshi YOSHIDA, Instantaneous Flooding and α-Tocopherol Content in Tuberous Roots of Sweetpotato (Ipomoea batatas (L.) Lam.), Environmental Control in Biology, 53, 1, 13-16, 2015.03, Compared to sub-irrigated sweetpotatoes (Ipomoea batatas (L.) Lam.), periodic surface-irrigated plants, i.e., twice a week on root media, showed increased α-tocopherol content in their tuberous roots with no apparent changes in both of tuberous root development and oxygen concentration around the roots. We speculated that surface irrigation might temporarily cover the tuberous root surface with water and inhibit oxygen movement into the roots, thereby increasing the antioxidant α-tocopherol content, for coping with the slight oxidative stress occurring within the roots. Therefore, we performed 1-3 times instantaneous flooding, with different intervals, which perfectly covered the whole root surface with water, of sweetpotato plants grown in a phytotron glass room (25℃, 70%RH). Electrolyte leakage from the tuberous root flesh cells showed a temporal increase for the flooding treatment, while it immediately recovered within 24 h. Instantaneous flooding did not affect the storage root development in any of the experiments. Apparent increases in the α-tocopherol content were observed during the 3-time flooding at 3-day intervals. Our results suggest that more frequent root surface wetting is necessary for increasing the α-tocopherol content, which is released because of the oxidative stress that occurs within the roots..
11.	江口壽彦, 田中宏幸, 吉田敏, 松岡健, Influence of Ground Water Level on the Growth of the Medicinal Plant Pinellia ternata Breit. in a Solid Substrate Culture System, The international conference on plant factory 2014, 2014.11, Many crude drugs used in Kampo medicines in Japan represent untapped medicinal resources. Domestication of the wild plants from which these drugs are derived and preservation of their natural habitats are necessary for establishing a stable supply of Kampo medicines. Here, we investigated the influence of the moisture condition of root medium on the growth of Pinellia ternata Breit. by using a sub-irrigation solid substrate culture system. The moisture condition was controlled by maintaining a constant ground water level (GWL). Plants were grown for 15 weeks under a GWL of either 4 cm (GWL-4) or 8 cm (GWL-8) below the corm base in a phytotron glass room at 25°C and 70% relative humidity. The water content of the root media around the corm in GWL-4 was only 1% higher than that in GWL-8. However, water content apparently affected corm enlargement and the development of new bulbils. Relative yield of the corm per plant, compared with the initial weight, was ~400% in GWL-4 and ~200% in GWL-8. The number of bulbils produced in a plant was 13.5 in GWL-4 and 4.4 in GWL-8. The effective ingredient, a kind of water-soluble polysaccharide consisting mainly of arabinose, was about 10% higher in GWL-8 corms than in GWL-4 corms. Moreover, when comparing the two conditions, the relative difference in corm yield was remarkably larger than that observed for the effective ingredient content. Overall, productivity was considered to be higher in GWL-4 than in GWL-8..
12.	Maruo, K., Kitano, M., Eguchi, T., Zushi, K., Nakazono, K., Yoshioka, T., Katsuda, M., Tokuda, A., Matsuo, K., Cold acclimation of tea plants and accumulation of compatible solutes, PR-P-62, 2013.11.
13.	Toshihiko EGUCHI, Yuji ITO and Satoshi YOSHIDA, Periodical Wetting Increases α-Tocopherol Content in the Tuberous Roots of Sweetpotato (Ipomoea batatas (L.) Lam.), Environment Control in Biology, 50, 3, 297-303, 2012.09, Tuberous root growth and antioxidant contents of 2 sweetpotato (Ipomoea batatas (L.) Lam.) cultivars were examined using 2 different irrigation schemes: surface-irrigation and sub-irrigation. Coarse silica sand was used for root media, which maintained well the gas permeability and water drainage around the roots. The root surface was periodically wetted for watering in the surface-irrigated roots, while the sub-irrigated roots were not. The irrigation methods did not affect the oxygen concentration around the roots. No differences in plant growth were observed between the 2 irrigation methods. However, the content of α-tocopherol in the tuberous root was significantly higher in the ordinary-irrigated roots for both of two cultivars. Thus, the periodical wetting increased the α-tocopherol content in the tuberous root of sweetpotato cultivars without any apparent changes in tuberous root development..
14.	Ryosuke Nomiyama, Kenji Ebihara, Motoki Takata, Daisuke Sakamoto, Yuki Sago, Daisuke Yasutake, Atsushi Marui, Toshihiko Eguchi, Makito Mori, Takuya Araki, Kenta Tagawa, Hiroyuki Cho, Yueru Wu, Weizhen Wang and Masaharu Kitano, Root Absorptive Functions Drive Salt Accumulation in Crop Fields under Desertification II. Effects of Different Plant Species, Eco-Engineering, 24, 3, 69-75, 2012.07, A cropped soil column system was used to analyze water and ion dynamics in soil affected by root absorptive functions of different crop species. The respective soil columns were cropped with corn, sunflowers, beets, and frog-fruits (i.e. cover grass), where the salinized groundwater was supplied as found in the salinized crop fields under desertification. In the corn and sunflower columns, the increased transpiration of leaves and decreased Na+ and Cl- absorbing power of roots resulted in increased salt accumulation in the soil, while the major essential ions of NO3-, PO43- and K+ were actively absorbed by roots and scarcely remained in the soil. In the beet and frog-fruit columns, it was considered that transpiration was low compared with the corn and sunflower columns and also soil surface evaporation was depressed by leaves growing horizontally over the soil surface. Furthermore, beet roots showed uniquely high Na+ and Cl- absorbing power. These factors resulted in decreased salt accumulation in the soil of the beet and frog-fruit columns. The lowest salt accumulation occurred in the no-crop column (without leaf transpiration and root absorptive functions). These results demonstrated that the transpiration, active and selective ion absorption, and leaf morphology of different plant species have a large influence on the amount and composition of ions accumulated in the soil..
15.	Yano, T., Kawano, T., Ohara, M., Sato, Y., Kotegawa, R., Kagawa, H., Setoyama, S., Yokota, N., Nomiyama, R., Araki, T., Yasunaga, Y., Eguchi, T., Kitano, M. , Water and carbon balance in developing fruit of the Satsuma mandarin (Citrus unshu Marc.). , Environment Control in Biology, 50, 2, 189-198, 2012.06.
16.	Toshihiko EGUCHI, Takehiko SUZUKI, Satoshi YOHSIDA, Ikuo MIYAJIMA, Masaharu KITANO, Time-course Pattern of Carrot Storage Root Growth in a Solid Substrate, Sub-irrigation Culture System, Environment Control in Biology, 49, 4, 177-183, 2011.12.
17.	Toshihiko EGUCHI, Satoshi YOSHIDA, Tuberous Root Thickening: A Rapid Response to Hypoxia in Sweetpotato (Ipomoea batatas (L.) Lam.), Environment Control in Biology, 49, 1, 47-50, 2011.03.
18.	Yuki SAGO, Daisuke YASUTAKE, Kota HIDAKA, Eriko YASUNAGA, Toshihiko EGUCHI, Satoshi YOSHIDA, Masaharu KITANO., Kinetics of root ion absorption affected by environmental factors and transpiration I. Measurement system for intact roots., Environment Control in Biology, 49, 1, 23-31, 2011.03.
19.	Yuki SAGO, Daisuke YASUTAKE, Kota HIDAKA, Eriko YASUNAGA, Toshihiko EGUCHI, Satoshi YOSHIDA, Masaharu KITANO., Kinetics of root ion absorption affected by environmental factors and transpiration II. Environmental effects and a concentration-dependent model., Environment Control in Biology, 49, 1, 33-40, 2011.03.
20.	Yuki SAGO, Daisuke YASUTAKE, Kota HIDAKA, Eriko YASUNAGA, Toshihiko EGUCHI, Satoshi YOSHIDA, Masaharu KITANO., Kinetics of root ion absorption affected by environmental factors and transpiration III. A kinetic model integrated with transpiration., Environment Control in Biology, 49, 1, 41-46, 2011.03.
21.	Ito, Y., Miyamoto, H., Yasunaga, E., Eguchi, T. and Chikushi, J. Application of ECH2O probes to the environmental control field in biology. Journal of the Japanese Society of Soil Physics　No. 114:33-36..
22.	T. Eguchi, T. Suzuki, H. Miyamoto, M. Hamakoga, S. Yoshida, J. Chikushi and M. Kitano. Influence of Ground Water Level on Carrot Growth in Solid Substrate Culture System. Journal of Science and High Technology in Agriculture (J. SHITA) 21(2): 65-71..
23.	H. Miyamoto, S. Yoshida, J. Chikushi， T. Eguchi and Y. Ito. Estimation of Moisture Conditions in Organic and Inorganic Growing Media Based on Hydraulic Properties. Journal of Science and High Technology in Agriculture (J. SHITA) 21(2): 72-78..
24.	H. Miyamoto, H. Cho, Y. Ito, J. Chikushi and T. Eguchi. General Calibration of Capacitance Soil Moisture Sensor for Various Electrical Conductivity Conditions. Journal of Science and High Technology in Agriculture (J. SHITA) 21(2): 86-91..
25.	Toshihiko EGUCHI, Satoshi YOSHIDA , Effects of Application of Sucrose and Cytokinin to Roots on the Formation of Tuberous Roots in Sweetpotato (Ipomoea batatas (L.) Lam.), Plant Root, Volume 2, p. 7-13, 2008.03, [URL].
26.	T. Eguchi, S. Moriyama, I. Miyajima, S. Yoshida and J. Chikushi A Hydroponic Method Suitable for Tops Production of a Sweetpotato Cultivar 'Suioh'. Journal of Science and High Technology in Agriculture (J. SHITA) 19(4): 167-174..
27.	Toshihiko EGUCHI, Satoshi YOSHIDA, Effects of gas exchange inhibition and hypoxia on tuberous root morphogenesis in sweetpotato (Ipomoea batatas (l.) Lam.)., Environment Control in Biology, Volume 45, No. 2, p. 103-111, 2007.06.
28.	X. D. Qian, T. Eguchi, S. Yoshida and J. Chikushi, Effects of zinc chemistry on phytoextraction in Thlaspi caerulescens-Vermiculite system., Journal of the Faculty of Agriculture, Kyushu University, 50, 2, 459-469, Vol. 50(2), 459-469, 2005.10.
29.	X. D. Qian, T. Eguchi, S. Yoshida and J. Chikushi, Analytical model for zinc uptake by root system of Thlaspi caerulescens., Journal of the Faculty of Agriculture, Kyushu University, 50, 2, 443-458, Vol. 50(2), 443-458, 2005.10.
30.	T. Eguchi and S. Yoshida, A Cultivation Method to Ensure Tuberous Root Formation in Sweetpotatoes (Ipomoea batatas (l.) Lam.)., Environment Control in Biology, Vol. 42(4): 259-266, 2004.12.
31.	T. Araki, T. Eguchi, T. Wajima, S. Yoshida and M. Kitano, Dynamic Analysis of Growth, Water Balance and Sap Fluxes through Phloem and Xylem in a Tomato Fruit: Short-term Effect of Water Stress., Environment Control in Biology, Vol. 42(3): 225-240, 2004.09.
32.	T. Eguchi, T. Araki, S. Yoshida and M. Kitano, Xylem Sap Backflow from Tomato Fruit under Water Deficit Condition, Acta Horticulturae, 618, 347-351, Vol. 618: 347-351, 2003.12.
33.	T. Eguchi, M. Kitano, S Yoshida and J. Chikushi, Root temperature effects on tuberous root growth of sweetpotato (Ipomoea batatas Lam.) -Direct and indirect effects of temperature-, Environment Control in Biology 41(1):43-49, 2003..
34.	T. Araki, M. Kitano, K. Okano, S. Yoshida and T. Eguchi, Environmental effects on dynamics of fruit growth and photoassimilate translocation in tomato plants (3) -Effect of salt stress-, Environment Control in Biology 39(1):53-58, 2001..
35.	T. Eguchi, A new method for on-line measurement of diurnal change in potato tuber growth under controlled environments, Journal of Experimental Botany, 10.1093/jexbot/51.346.961, 51, 346, 961-964, Vol. 51(346): 961-964, 2000.05.
36.	M. Kitano, T. Araki, S. Yoshida and T. Eguchi, Dependence of calcium uptake on water absorption and respiration in roots of tomato plants (Lycopersicon esculentum Mill.), Biotronics, Vol. 28: 121-130, 1999.12.
37.	T. Eguchi, M. Kitano and H. Eguchi, Growth of tuberous root as affected by the ambient humidity in sweetpotato (Ipomoea batatas Lam.), Environment Control in Biology 37(3):197-201, 1999..
38.	T. Eguchi, M. Kitano and H. Eguchi, Growth of sweet potato tuber as affected by the ambient humidity, Biotronics, Vol. 27: 93-96 (Short Communication), 1998.12.
39.	T. Eguchi, M. Kitano and H. Eguchi, Water relations and dynamics of tuber growth rate in sweet potato plants (Ipomoea batatas Lam.), Environment Control in Biology 36(2):91-95, 1998..
40.	T. Eguchi, M. Kitano and H. Eguchi, Effect of root temperature on sink strength of tuberous root in sweet potato plants (Ipomoea batatas Lam.), Biotronics, Vol. 23: 75-80, 1994.12.

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