Pearcy R W
Department of Biological Sciences, State University of New York at Albany, Albany, New York 12222.
Plant Physiol. 1977 May;59(5):795-9. doi: 10.1104/pp.59.5.795.
Atriplex lentiformis plants collected from coastal and desert habitats exhibit marked differences in capacity to adjust photosynthetic response to changes in growth temperature. Plants from desert habitats grown at 43 C day/30 C night temperatures had higher CO(2) uptake rates at high temperatures but reduced rates at low temperatures as compared to plants grown at 23 C day/18 C night temperatures. In contrast, growth of the coastal plants at high temperatures resulted in markedly reduced photosynthetic rates at all measurement temperatures.Leaf conductances to CO(2) were not important in controlling either the differences in the temperature dependence of net CO(2) uptake or the differences in photosynthetic capacities at any measurement temperature. At low measurement temperatures, differences in photosynthetic capacities among plants acclimated to the contrasting growth regimes were correlated with differences in leaf ribulose diphophate carboxylase activities. At high measurement temperatures, the improved net photosynthetic performance of the high temperature acclimated desert plants appeared to be due to a combination of decreased respiration rates, decreased temperature dependence of respiration, and an apparent increased thermal stability of photosynthetic CO(2) exchange.
从沿海和沙漠栖息地采集的滨藜属植物在调节光合作用对生长温度变化的响应能力上表现出显著差异。与在白天23℃/夜间18℃温度下生长的植物相比，在白天43℃/夜间30℃温度下生长的沙漠栖息地植物在高温下具有更高的二氧化碳吸收速率，但在低温下速率降低。相比之下，沿海植物在高温下生长导致在所有测量温度下光合速率显著降低。叶片对二氧化碳的传导率在控制净二氧化碳吸收的温度依赖性差异或任何测量温度下的光合能力差异方面并不重要。在低测量温度下，适应不同生长环境的植物之间光合能力的差异与叶片核酮糖二磷酸羧化酶活性的差异相关。在高测量温度下，适应高温的沙漠植物净光合性能的改善似乎是由于呼吸速率降低、呼吸对温度的依赖性降低以及光合二氧化碳交换的热稳定性明显提高的综合作用。
