比较分析了植物光合同化CO2速率、Rubisco活 性等性状对长期和短期高浓度CO2的反应.结果表明：所研究的植物在高浓度CO2下生长 ，可以长期保持高的CO2同化速率；长期在高浓度CO2下生长植物的光合速率增加有两个 来源，其一，是CO2浓度增加而增加的底物浓度效应(ΔPc)，它的大小随外界短期C O2浓度改变而改变，其二，是植物光合系统结构改变而提高光合能量转换或是电子传递效 率所产生的光合速率增加(ΔPs)，它的大小不随外界短期CO2浓度变化而改变。植 物光合速率对大气CO2浓度升高的增加量是上述两者之和.%We compared the photosynthetic rate, CO2 uptake curves of light saturation, Ruisco activities of plants grown under different CO 2 concentration in the air. The results show that under enriched CO2 conditi ons plants occupied higher photosynthetic rate during the whole growth season an d did not show any down regulation. The photosynthetic rate is constituted by 2 components, one of which is a CO2 concentration dependant CO2 uptake(ΔP c) which changes with CO2 concentration in the air, and the other is the str ucture of photosystem dependant CO2 uptake(ΔPs) that has a nature of ph otosynthetic energy conversion or electron transport, which is an adaptation of plant to the high CO2 and does not change with the short-term variation of co ncentration in the air. The CO2 concentration determines the affinity to Rubis co, and the structure of photosystem effects the efficacy of photosynthetic elec tron transportaion. Thus influence of CO2 on the photosynthetic rate(ΔP) can be presented as the following：ΔP=ΔPc+ΔPs.
展开▼
