1989 Fiscal Year Final Research Report Summary
Proton and ion transport in plant membrane systems.
| Project/Area Number |
62480010
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
植物生理学
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| Research Institution | Kyushu University |
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Principal Investigator |
NISHIMURA Mitsuo Kyushu University, Faculty of Science, Professor, 理学部, 教授 (40037255)
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| Co-Investigator(Kenkyū-buntansha) |
ARATA Hiroyuki Kyushu University, Faculty of Science, Assistant, 理学部, 助手 (80151166)
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| Project Period (FY) |
1987 – 1989
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| Keywords | Ion transport in plant cells / Chloroplast / Thylakoid membrane / Tonoplast / CAM plant / Malate transport / Oxygen-evolving system / Photosystem II |
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| Research Abstract |
We studied the molecular mechanisms and regulation of proton and ion transport in membranes of plant cells and organelles. The relationship between the maintenance of plant cell functions, homeo stasis and ion transport was also analyzed.
1. The light-induced, reversible and non-vectorial proton release from uncoupled thylakoid membranes was accompanied by conformational changes of thylakoid polypeptide(s) which showed changes in the reactivity of thiol groups.
2. Proton and malate transport across the tonoplast membyane was studied electrophysiologically by the patch clamp technique. Stoichiometry of 2:1 was maintained in the proton and malate transport to keep the electroneutrality. The presence of isocitric acid in vacuoles served for the buffering of vacuolar pH and to allow the large span of malate transport.
3. The transport and local concentration of chloride ion were studied in connection to the activity of oxygen production and the distribution of membrane surface charges. The structure of reaction center II was discussed in terms of charge distribution, accessibility of ions and magnetic interaction between internal components and external paramagnetic ions.
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