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Explication of leaf-level acclimations and adaptation to the low atmospheric pressure at high altitude

叶面驯化和高海拔低气压适应的解释

基本信息

批准号：
11640638
负责人：
YOKOI Yota
金额：
$ 2.24万
依托单位：
Kitasato University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

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.

为了研究CO_2和O_2分压降低对高海拔高山植物叶级光合作用的影响，我们比较了Reynoutria japonica Houtt的最大羧化效率CE。变种。粳稻生长在高原，粳稻生长在低地。高地种群在原生大气条件下的CE（原生CE）显着低于低地种群。高地人群CE对O_2的依赖性显着低于低地人群。通过理论分析，我们解释了随着内电导（g_I）的降低，叶级光合作用的O_2依赖性减弱。我们还表明，g_I 和活性 rubisco (E) 的含量可以根据叶级光合作用的 O_2 依赖性来估计。通过应用分析，估计高地种群中CO_2在叶子中扩散的严重限制，而两个种群中估计的E值几乎相同。原生CE差异的合理解释除了CO_2和O_2分压差异外，高地种群g_I较小导致O_2依赖性和光合能力较小。