Sage R F, Sharkey T D, Seemann J R
Department of Botany, University of Georgia, Athens, Georgia 30602.
Plant Physiol. 1989 Feb;89(2):590-6. doi: 10.1104/pp.89.2.590.
The effect of long-term (weeks to months) CO(2) enhancement on (a) the gas-exchange characteristics, (b) the content and activation state of ribulose-1,5-bisphosphate carboxylase (rubisco), and (c) leaf nitrogen, chlorophyll, and dry weight per area were studied in five C(3) species (Chenopodium album, Phaseolus vulgaris, Solanum tuberosum, Solanum melongena, and Brassica oleracea) grown at CO(2) partial pressures of 300 or 900 to 1000 microbars. Long-term exposure to elevated CO(2) affected the CO(2) response of photosynthesis in one of three ways: (a) the initial slope of the CO(2) response was unaffected, but the photosynthetic rate at high CO(2) increased (S. tuberosum); (b) the initial slope decreased but the CO(2)-saturated rate of photosynthesis was little affected (C. album, P. vulgaris); (c) both the initial slope and the CO(2)-saturated rate of photosynthesis decreased (B. oleracea, S. melongena). In all five species, growth at high CO(2) increased the extent to which photosynthesis was stimulated following a decrease in the partial pressure of O(2) or an increase in measurement CO(2) above 600 microbars. This stimulation indicates that a limitation on photosynthesis by the capacity to regenerate orthophosphate was reduced or absent after acclimation to high CO(2). Leaf nitrogen per area either increased (S. tuberosum, S. melongena) or was little changed by CO(2) enhancement. The content of rubisco was lower in only two of the five species, yet its activation state was 19% to 48% lower in all five species following long-term exposure to high CO(2). These results indicate that during growth in CO(2)-enriched air, leaf rubisco content remains in excess of that required to support the observed photosynthetic rates.
研究了在300或900至1000微巴的二氧化碳分压下生长的5种C3植物（藜、菜豆、马铃薯、茄子和甘蓝）长期（数周至数月）二氧化碳浓度升高对（a）气体交换特性、（b）1,5-二磷酸核酮糖羧化酶（rubisco）的含量和活化状态以及（c）单位面积叶片氮、叶绿素和干重的影响。长期暴露于高浓度二氧化碳对光合作用的二氧化碳响应有三种影响方式：（a）二氧化碳响应的初始斜率不受影响，但高浓度二氧化碳下的光合速率增加（马铃薯）；（b）初始斜率降低，但二氧化碳饱和光合速率受影响较小（藜、菜豆）；（c）二氧化碳响应的初始斜率和二氧化碳饱和光合速率均降低（甘蓝、茄子）。在所有5种植物中，高浓度二氧化碳下生长增加了在氧气分压降低或测量的二氧化碳浓度高于600微巴时光合作用受到刺激的程度。这种刺激表明，在适应高浓度二氧化碳后，正磷酸盐再生能力对光合作用的限制减少或不存在。单位面积叶片氮含量要么增加（马铃薯、茄子），要么受二氧化碳浓度升高影响不大。在5种植物中只有2种的rubisco含量较低，但长期暴露于高浓度二氧化碳后，所有5种植物的rubisco活化状态均降低了19%至48%。这些结果表明，在富含二氧化碳的空气中生长期间，叶片rubisco含量仍超过支持观察到的光合速率所需的量。
