| Project/Area Number |
08660070
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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 |
Plant nutrition/Soil science
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| Research Institution | Yamagata University |
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Principal Investigator |
WAGATSUMA Tadao Yamagata University, Faculty of Agriculture, Professor, 農学部, 教授 (70007079)
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| Co-Investigator(Kenkyū-buntansha) |
IKARASHI Taro Niigata University, Faculty of Agriculture, Professor, 農学部, 教授 (50018537)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1997: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1996: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Al tolerance / CEC / FDA-PI / Permeability / Plasma membrane / Protoplast / Release of citric acid / Root tip |
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| Research Abstract |
Discrimination of the responses of root to Al ions while binding with root from that while root elongation is important to clarify the mechanism of Al tolerance. Results are as follows. Al content in root-tip cells treated with high concentration of Al correlated negatively with Al tolerance among plant species, but did not correlate with CECs both of root-tip portion and cell wall isolated from root-tip portion. CEC of cell wall from root-tip portion hardly changed after Al treatment, and did not correlated with Al tolerance, either. The concentrations of K,P and Mg in root-tip portion considerably decreased with Al treatment in Al-sensitive plant species. The same tendency was observed in Al-sensitive cultivars of rice, maize, pea, wheat and sorghum. The concentrations of K and Cl in 2 mm tip-portion of roots treated with 20 muM Al for 1 h were higher in Al-tolerant rice, but lower in Al-sensitive barley by EPMA analysis. Efflux of K from root agreed with the former result. Permeabil
… More
ity of the plasma membrane (PM) of root-tip cells in any kind of plant species was normal just after the treatment with 100 muM Al for 1 h (FDA-PI fluorescence staining) ; destruction of the PM was considerable in Al-sensitive plant speecies following several hours of re-elongation of root in the medium without Al, but a short-term post-treatment with citric acid following the treatment with Al restored its normal permeability. The permeability of PM of protoplasts isolated from root-tip cells of Al-sensitive plant species was considerably incteased after hypotonic treatment without Al following a temporaty treatment with Al. Al concentration ratio of protoplasts to protoplast ghosts was nearly one in Al-sensitive plant species. Differences in amounts of the release of organic acids, especially citric acid, from roots did not correspond to the differences in Al tolerance among plant species and cultivars. PM of root-tip cells of Al-sensitive plants may be saturated with Al ions more instantly after Al treatment, increased its permeability, and finally K leakage and Al permeation from PM may be induced considerably in Al-sensitive plants. Elongation of root accelerates Al toxicity. Lipid composition of PM of root-tip cells may finally determine Al tolerance. Less
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