Abstract:

With reference to the recent achivements about the structure, spectra and kinetics of light-harvesting complex (LHCⅡ) in PSⅡ of higher plants, a four-level model was provided to simulate the energy transfer process from LHCⅡ to the reaction center. On the basis of this model, a set of rate equation was established. Analysis of its algebra solution led to a general picture of energy transfer process in LHCⅡ of higher plants and the strong interaction among pigment molecules in this process. Based on the spectra, kinetics and biological structural data providing some information of energy transfer path and energy dissipation mechanism, it has been found that energy transfer mainly happened between the pigments whose energy level was most closely adjacent, the loss of energy had a close relation to the process of energy transfer and tended to increase with the decrease of energy level. The protective mechanism of antenna system was also discussed.

高等植物光系统II捕光复合体向反应中心能量传输的四能级理论
张舒^1,2  贺俊芳¹ 王水才¹ 侯洵¹ 李良璧³  匡廷云³

（1. 中国科学院西安光学精密机械研究所瞬态光学技术国家重点实验室，西安710068；
2. 西北大学光子学与光子技术研究所，西安710069；3. 中国科学院植物研究所光合作用基础研究开放实验室，北京100093）

摘要：结合近年来对光系统II中捕光复合体（LHCII)的结构，光谱和动力学研究成果，提出了一个四能级模型来模拟能量从LHCII向反应中心的传递，并根据这个模型建立了一组速率方程，从理论的角度分析了高等植物光系统IILHCII中的能量传递过程，根据计算结果从整上描述了光系统II外周天线向反应中心的传能机制，并发现此过程中分子间有较强的相互作用，针对LHCII光谱，动力学特性和生物体结构解析进行了进一步的近拟，讨论了LHCII的能量传递的大致途径和耗散机制，认为分子间能量传递的主要方式是在能组相邻分子间的传递，损耗是能量传递过程紧密相关，随能级的降低损耗增大，对光强过强时的光保护机制也进行了探讨。

关键词： LHC II；四能级模型；速率方程；传能；耗散

Key words: LHCⅡ, four-level model, rate equation, energy transfer, energy dissipation