H_2O_2胁迫下菠菜叶片延迟发光动力学过程的分析

从生物延迟发光的机理出发,建立了生物延迟发光动力学方程,发现菠菜叶片的延迟发光随时间按双指数规律衰减,表明菠菜叶片延迟发光来源于快项和慢项两个发光系统,其动力学行为可以通过发光动力学参数积分强度、初始光子数和衰变时间定量描述。用体积分数为10%的H2O2溶液处理菠菜叶片,随着处理时间的延长,延迟发光积分强度和初始光子数快速降低,积分强度和初始光子数的变化呈正相关,表征快相和慢相发光特征的两个衰变时间表现出逐渐减小的趋势。积分强度和初始光子数的变化代表了叶片的光合能力和代谢强度的下降,衰变时间的变化暗示H2O2可能对叶片PSⅡ中D1和D2两条多肽造成了破坏。

Analysis of Delayed Luminescence Dynamic Processes of Spinach Leaves Stressed by H2O2

Dynamic model of delayed luminescence of spinach leaves was proposed based on the mechanism of delayed luminescence in biological system. Delayed luminescence of spinach leaves reduced with time according to double-exponential law,it showed that delayed luminescence of spinach leaves comes from fast and slow items of light-emitting elements. The characteristics of delayed luminescence could be accurately described by parameters such as initial photon number I(0),integrated intensity I(T) and decay time of delayed luminescence. Treated by solution of 10% H2O2, I(T) and I(0) decreased rapidly with treatment time, the changes of integrated intensity I(T) is proportional to changes of initial photon number I(0). Two decay times of the fast and slow items of light-emitting elements gradually decreased. The changes of I(T) and I(0) of delayed luminescence could represented decline in photosynthetic capacity and metabolic intensity of cell. The changes of decay times suggested that polypeptide D1 and D2 in PS Ⅱ of photosynthetic cells could be damaged by H2O2.