Photosynthetic rates and partitioning of absorbed light energy in photoinhibited leaves
Photosynthetic rates and partitioning of absorbed light energy in photoinhibited leaves
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DOI：
10.1111/j.1399-3054.2004.00364.x
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发表时间：
2004-08-01
影响因子：
6.4
通讯作者：
Hirose, T
中科院分区：
文献类型：
--
作者：
Hikosaka, K;Kato, MC;Hirose, T
研究了光抑制对藜麦叶片光合碳增益影响的评价参数。测定了36 Pa CO2分压下光合速率的光响应曲线，并用非直角双曲线拟合。在受光抑制的叶片中，曲线的初始斜率和光饱和速率都有所下降，但后者的下降幅度较小。在受光抑制的叶片中，曲线的凹凸度也较小。根据co2响应曲线估计了核酮糖-1,5-二磷酸羧化能力（V-cmax）和电子传递能力（J(max)）。V-cmax和J（max）随光抑制的增加而降低。利用叶绿素荧光参数估计光系统II （PSII）的能量分配。光化学消耗的能量比例随着光抑制的增加而降低。然而，非活性PSII的增加，减少了对活性PSII的能量分配，降低了PSII中的激发压力，导致既不被光化学消耗也不作为热量消散的多余能量的比例减少。
Parameters for the evaluation of the effects of photoinhibition on photosynthetic carbon gain were studied in Chenopodium album leaves. The light-response curve of photosynthetic rate was determined at 36 Pa CO2 partial pressure and fitted by a non-rectangular hyperbola. Both the initial slope of the curve and the light-saturated rate decreased in photoinhibited leaves, although the decrease in the latter was small. The convexity of the curve was also smaller in photoinhibited leaves. The capacities of ribulose-1,5-bisphosphate carboxylation (V-cmax) and electron transport (J(max)) were estimated from the CO2-response curves. V-cmax and J(max) decreased similarly with increasing photoinhibition. Energy partitioning in photosystem II (PSII) was estimated using chlorophyll fluorescence parameters. The fraction of energy that was consumed by photochemistry decreased with increasing photoinhibition. However, an increase in inactive PSII, decreasing energy partitioning to active PSII, relaxed the excitation pressure in PSII, and led to a reduction in the fraction of excess energy that was neither consumed by photochemistry nor dissipated as heat.