Project/Area Number |
17380013
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Crop science/Weed science
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Research Institution | KYUSHU UNIVERSITY |
Principal Investigator |
IWAYA Mari Faculty of Agriculture, Faculty of Agriculture, Professor, 大学院農学研究院, 教授 (60091394)
|
Co-Investigator(Kenkyū-buntansha) |
ZHENG Shao-Hui Saga University, Marine and Highland Bioscience Center, Associate Professor, 海浜台地生物環境研究センター, 助教授 (90253517)
SHIMAZAKI Ken-ichiro Kyushu University, Faculty of Sciences, Professor, 大学院理学研究院, 教授 (00124347)
YUASA Takashi Kyushu University, Faculty of Agriculture, Associate Prof, 大学院農学研究院, 助教授 (40312269)
|
Project Period (FY) |
2005 – 2006
|
Project Status |
Completed (Fiscal Year 2006)
|
Budget Amount *help |
¥16,000,000 (Direct Cost: ¥16,000,000)
Fiscal Year 2006: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥12,400,000 (Direct Cost: ¥12,400,000)
|
Keywords | Dynamic states of water / drought resistance / seed / cowpea / NMR relaxation time / ABA (Abscisic acid) / stomata / ABA / 蒸散速度 / 水蒸気コンダクタンス / 砂漠化 / トレハロース |
Research Abstract |
The problems of desertification cause imbalance in the ecosystem, resulting in a large decrease of water which could be used for crop production. Cowpea are major crops in the semi-arid zone of the Sahel. In this research the relationship between NMR relaxation times, photosynthetic parameters and expression of abscisic acid (ABA) related genes in cowpea plants induced by drought stress. When cowpea and other pea plant were subjected to water stress, transpiration rate and vapor diffusion conductance of cowpea leaves were reduced at significantly high rate in short time after the stress treatment. The observation indicates that cowpea lessened its water loss via transpiration by so quickly responsiveness to drought stress. In the contrast to the parameters of photosynthesis, water content and ^1H-NMR relaxation times (T_1,T_2) representing water molecule status in cowpea leaves were retained or gradually increased while cowpea was subjected to drought stress. In the next, we focused on gene expression profiles of 9-cis-epoxycarotenoid dioxygenase (NCED) and zeaxanthin epoxidase (ZEP) which are both key enzymes for synthesis of ABA. When cowpea and soybean were subjected to drought stress, induction of NCED mRNA was observed in cowpea roots 6 days earlier compared with that of soybean roots and ZEP is induced only in cowpea roots. Based on these results, it is suggested that ZEP and NCED are induced in cowpea roots under drought stress, and then increase of ABA levels leads to rapid stomatal closure, resulting in effective protection from water loss in its leaves (Iwaya-Inoue et al. 2006;Imamura et al. 2007,Proceedings). It was also studied that the mechanism of blue light-dependent stomatal opening which facilitates leaf wilting in crop plants (Takemiya et al. 2005,2006). Furthermore, drought tolerance in seeds as the most resistant organ was also investigated (Funaba et al. 2006,Ishibashi and Iwaya-Inoue 2006).
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