| Project/Area Number |
11640638
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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 |
生態
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| Research Institution | Kitasato University |
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Principal Investigator |
YOKOI Yota Kitasato University, Center of Natural Science, Professor, 一般教育(基礎科学センター), 教授 (90007758)
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| Co-Investigator(Kenkyū-buntansha) |
SAKATA Tsuyoshi Kitasato University, Center of Natural Science, Assistant Professor, 一般教育(基礎科学センター), 助手 (60205747)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | leaf-level photosynthesis / Low atmospheric pressure / Internal conductance / Rubisco / Leaf nitrogen / Leaf protein / Reynoutria japonica / Aconogonum weyrichii / 葉中窒素量 / 葉中タンパク質量 / 葉内ガス拡散コンダクタンス / 酸素分圧 / 葉内CO_2拡散コンダクタンス / ルビスコ活性 |
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| Research Abstract |
To examine the effects of decreased CO_2 and O_2 partial pressure on leaf-level photosynthesis in alpine plants at high altitude, we compared the maximal carboxylation efficiency CE, of Reynoutria japonica Houtt. Var. japonica growing in a highland with one growing in a lowland. CE under the native atmospheric conditions (native CE) of the highland population was significantly lower than that of the lowland one. The O_2 dependency of CE was significantly less in the highland population than in the lowland. Using theoretical analysis, we explained that O_2 dependency of leaf-level photosynthesis became less as internal conductance (g_I) decreased. We also showed that g_I and the content of active rubisco (E) could be estimated from the O_2 dependency of leaf-level photosynthesis. By applying the analysis, a severe limitation of CO_2 diffusion in the leaf was estimated in the highland population whereas almost the same values of E were estimated in both populations. A reasonable explanation for the difference in the native CE is the smaller O_2 dependency and photosynthetic capacity caused by a smaller g_I in the highland population in addition to the differences in the partial pressures of CO_2 and O_2.
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