| Project/Area Number |
16370026
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Tokyo Metropolitan University |
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Principal Investigator |
KOSHIBA Tomokazu Tokyo Metropolitan University, Biological Sciences, Professor, 都市教養学部・理工学系, 教授 (80117704)
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| Co-Investigator(Kenkyū-buntansha) |
OKAMOTO Takeshi Tokyo Metropolitan University, Biological Sciences, Associate Professor, 都市教養学部・理工学系, 准教授 (50285095)
SEO Mitsunori Riken, Yokohama Institute, Ph.D.Resarcher, 生殖制御研究グループ, 基礎科学特別研究員
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥15,600,000 (Direct Cost: ¥15,600,000)
Fiscal Year 2005: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2004: ¥12,600,000 (Direct Cost: ¥12,600,000)
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| Keywords | Abscisic acid / Biosynthesis / Transport / Water stress / Arabidosis thaliana / Vascular system / (長距離)輪送 / 孔辺細胞 / 植物ホルモン / ソラマメ |
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| Research Abstract |
The accumulation of abscisic acid (ABA) is essential for the response to drought stress in plants. Arabidopsis 9-cis-epoxycarotenoid dioxygenase 3 (AtNCED3) is known to act as a rate-limiting enzyme during stress-induced ABA biosynthesis. The expression of the AtNCED3 gene is up-regulated under water stress, which leads to the rapid accumulation of endogenous ABA in Axabidopsis. However, we have no information about the localization of AtNCED3 and therefore the precise site(s) of ABA biosynthesis remains to be determined. In the present study, we performed expression analysis of three important ABA biosynthetic enzymes, AtNCED3, AtABA2 and AAO3, using specific antibodies against each these enzymes. The results revealed thait the expression of AtABA2 and AAO3 was mainly in the vascular tissues of rosette veins in turgid plants and their patterns showed no significant changes after dehydration treatment. On the other hand, AtNCED3 could not be observed in any region of turgid plants, wbile drought-induced expression of AtNCED3 appeared in vascular region of the leaf veins. The localization patterns of AtNCED3, AtABA2 and AAO3 observed in serial sections of water-stressed rosette leaves indicated that these three enzymes were co-localized to the same cells of vascular parenchyma surrounding xylem and phloem. In addition, AtNCED3 was expressed in chloroplast of parenchyma cells adjacent to xylem vessels. These results suggest that drought induced ABA production occurs rapidly in vascular parenchyma cells, which may directly perceive the change in water potential of xylem and/or phloem upon exposure of water deficient stress. This is the first finding that shows close interaction between water stress perception and ABA biosynthesis in the vascular tissues in plants.
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