| Project/Area Number |
15570044
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
植物生理・分子
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| Research Institution | Meijo University |
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Principal Investigator |
TANAKA Yoshito Meijo University, Faculty of Science and Technology, Associate professor, 理工学部, 助教授 (10247679)
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| Co-Investigator(Kenkyū-buntansha) |
TAKABE Teruhiro Meijo University, General Institute, Professor, 総合研究所, 教授 (80097766)
HIBINO Takashi Meijo University, Faculty of Science and Technology, Associate professor, 理工学部, 助教授 (70218741)
石川 浩 名城大学, 理工学部, 助教授 (40076592)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2004: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2003: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | glycine bet-tine / Amaranthus / salt stress / choline monooxygenase / ベタイン |
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| Research Abstract |
1. Biosynthetic pathway of glycine betaine (GB) and its limiting step in GB accumulating plant.
Accumulation level of GB in excised leaves of Amaranthus under salt stress was increased by exogenous supply of choline. It suggests that endogenous supply of choline (a substrate for choline monooxygenase) is limiting at least in the initial phase of salt stress.
So the factors affecting GB accumulation was further investigated. It has been reported that choline is synthesized from serine via ethanolamine in plants. Photorespiration may have an important role in serine biosynthesis in photosynthetic tissue, so the effect of concentration of CO_2 on the accumulation of GB was studied. Under high concentration of CO_2, significant decrease in GB content was observed under salt-stressed condition. GB accumulation may depend on the synthesis of serine by photorespiration under salt stress.
2. Induction mechanism of GB synthesis in GB accumulating plant
Accumulation of choline monooxygenase (CMO) was observed within I day in real leaves and hypocotyls after transfer to salt stress. On the other hand, accumulation of CMO in cotyledons and roots relatively slowly occurred. Response to salt stress was different among plant tissues. When Amaranthus seedlings were transferred to darkness, accumulation of CMO did not occur even under salt stress. It shows the accumulation of CMO need light besides salt stress.
3. Regulation of gene expression of CMO
Upstream region of CMO gene was isolated and the CMO-promoter::GUS construct was made. By using this construct, transient assay was done with mature leaves of Amaranthus The expression analysis in transgenic Arabidopsis was also done with this construct. The suppressor and enhancer region in the DNA were identified.
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