Department of Forest Botany and Pathology, State University of New York College of Environmental Science and Forestry, Syracuse, New York 13210.
Plant Physiol. 1973 Feb;51(2):245-9. doi: 10.1104/pp.51.2.245.
Chloroplasts isolated from Populus deltoides leaves were used to study age-dependent changes in the rate of cyclic photophosphorylation. Single leaves were used to measure CO(2) fixation by leaf discs, chlorophyll concentration, and ATP synthesis. The ability of chloroplasts to synthesize ATP diminished steadily from the time of full leaf expansion, regardless whether the results are expressed on a leaf area or chlorophyll basis. This decline in the rates of ATP synthesis was paralleled by the decline in the rate of CO(2) fixation. The results suggest that the efficiency of the membrane-bound ATP synthesizing system declines with age.
从杨树叶中分离出的叶绿体被用于研究与年龄相关的环式光合磷酸化速率的变化。使用单叶来测量叶圆片的 CO2 固定、叶绿素浓度和 ATP 合成。无论结果是按叶面积还是叶绿素基础来表示，叶绿体合成 ATP 的能力从叶片完全展开时起就稳步下降。ATP 合成速率的下降与 CO2 固定速率的下降平行。结果表明，与年龄相关的是，膜结合的 ATP 合成系统的效率下降。
