延迟荧光(DF)技术在植物学、农业和环境等领域有着广泛的应用前景,延迟荧光来源的机理研究对其应用起着重要的作用.基于广泛接受的电子回流理论由一系列的光化学反应方程推导得出多指数衰减的延迟荧光动力学模型,首次提出了一个简化的三指数衰减近似模型,描述了光合电子传递链上的三个最重要成分的电子回流.为了验证近似模型的准确性,以实验室培养的相似的8周大的Jin Dan No. 39玉米叶片为模型样品,利用实验室自制的延迟荧光探测系统,得到延迟荧光衰减动力学曲线.分别用三种电子阻断剂:DCMU、DBMIB和Paraquat处理后的衰减动力学的实验与理论模型进行了对比研究,通过曲线特征来确定不同成分的存在及依赖关系.结果表明延迟荧光衰减动力学三指数拟合非常好(R2=0.99909),而且这三种成分是相互独立的,分别来源于QA, QB和光系统Ⅰ环式电子流.简化模型的提出为延迟荧光的应用题提供一个平台.%Delayed fluorescence (DF) technique has wide application foreground in the research of botany, agriculture, and environment and so on. The study of the mechanism for its origin plays an important role in the application of it. In the study, a multicomponents decay kinetics model of DF was deduced from a series of photochemical reaction equations based on the widely accepted theory of charge recombination. At the same time, a simplified three components approximation decay kinetic model was firstly proposed, which described the electronic reflux of three most significant components in the photosynthesis electron transport chain. To examine the accuracy of the approximation model, the lab-culture similar eight-week-old Jin Dan No. 39 leaves were adopted as the model sample to get the decay kinetics of DF using lab-made DF detection system. The comparison of theory model and experiments were accomplished in the presence of three electron blockers: DCMU, DBMIB, and Paraqaut. The results showed that the three components fit for decay kinetics of DF was very excellent (R2=0.99909). In addition, the three components had the independence and came from the electron reflux of QA, QB, and the cyclic electron flow around PSⅠ, respectively. This representation of the simplified model provides a workbench for the application of DF.
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