The photosynthetic properties of rice leaves treated with low temperature and high irradiance
The photosynthetic properties of rice leaves treated with low temperature and high irradiance
复制标题
DOI：
10.1093/pcp/pci149
复制
发表时间：
2005-08-01
影响因子：
4.9
通讯作者：
Mae, T
中科院分区：
文献类型：
--
作者：
Hirotsu, N;Makino, A;Mae, T
水稻光合作用特性的研究叶片在低温(15℃)和高光(1,500亩量子m(-2)S(-1))处理后进行观察。通过同时测量Chl荧光、P700(+)吸光度和气体交换，观察到PSII(Phi PSII)和PSI(Phi PSI)的量子效率和CO2同化速率都随着PSII的最大量子效率(F-v/F-m)的降低而降低。Phi PSII的下降与CO2同化的相关性最强。虽然1，5-二磷酸核酮糖(RuBP)羧化酶/加氧酶(Rubisco)的初始活性(提取后立即测量的活性)和总活性(用CO2和Mg2+预孵育后的活性)略有下降，但最大活性(用SO42-处理后的活性)几乎保持不变。这些结果表明，随着F-v/F-m的降低，CO2同化速率的下降不是由于Rubisco活性的降低，而是RuBP再生能力的降低，而RuBP再生能力的下降是由于线性电子传递速率的降低。另一方面，phi PSI的下降很小，phi PSI/Phi PSII的比率增加。叶黄素循环色素的脱环氧化状态也增加。因此，在光抑制叶片中发生了围绕PSI的循环电子传递。
Photosynthetic characteristics in rice (Oryza sativa L.) leaves were examined after treatment with low temperature (15 degrees C) and high irradiance (1,500 mu mol quanta m(-2) s(-1)). Decreases in quantum efficiencies in PSII (Phi PSII) and PSI (Phi PSI) and in the rate of CO2 assimilation were observed with a decrease in the maximal quantum efficiency of PSII (F-v/F-m) by simultaneous measurements of Chl fluorescence, P700(+) absorbance and gas exchange. The decreases in Phi PSII were most highly correlated with those in CO2 assimilation. Although the initial (the activity immediately measured upon extraction) and total (the activity following pre-incubation with CO2 and Mg2+) activities of ribulose-1,5-bisphosphate (RuBP) carboxylase/oxygenase (Rubisco) decreased slightly, the maximal activity (the activity following treatment with SO42-) of Rubisco remained almost constant. These results indicate that the decrease in CO2 assimilation rate with the decreasing F-v/F-m was not caused by a decrease in Rubisco activity but rather by a decrease in RuBP regeneration capacity which resulted from the decrease in the rate of the linear electron transport. On the other hand, the decrease in Phi PSI was very small and the ratio of Phi PSI to Phi PSII increased. The de-epoxidation state of xanthophyll cycle pigments also increased. Thus, the cyclic electron transport around PSI occurred in photoinhibited leaves.