Department of Biology, University of Dayton, Dayton, Ohio 45469.
Plant Physiol. 1984 Nov;76(3):763-8. doi: 10.1104/pp.76.3.763.
The relationship between CO(2) concentration and starch synthesis and degradation was studied by measuring leaf starch content and disappearance of (14)C-starch. At a concentration of 340 microliters CO(2) per liter, starch accumulated without degradation of previously synthesized starch. Degradation of starch began when CO(2) concentration was lowered, but its synthesis continued. At 120 microliters CO(2) per liter rates of synthesis and degradation were equal. Even at the CO(2) compensation point, synthesis of starch continued. Concomitant starch synthesis and mobilization supported export from the leaf. Changes in starch metabolism that occur when photosynthesis is CO(2)-limited provide a means to study regulation of starch metabolism and carbon allocation in translocating leaves.
通过测量叶片淀粉含量和(14)C-淀粉的消失,研究了 CO2 浓度与淀粉合成和降解之间的关系。在 340 微升/升 CO2 的浓度下,淀粉积累而不降解先前合成的淀粉。当 CO2 浓度降低时,淀粉开始降解,但合成仍在继续。在 120 微升/升 CO2 的浓度下,合成和降解的速率相等。即使在 CO2 补偿点,淀粉的合成仍在继续。同时进行的淀粉合成和动员支持了叶片的输出。光合作用受到 CO2 限制时淀粉代谢的变化为研究转运叶片中淀粉代谢和碳分配的调节提供了一种手段。