【作者】 陈中伟； 李伟； 徐英凯； 刘斌； 孙健； 刘科； 沈萍萍； 刘扬；

【Author】 Z.W.Chen~a W.Li~b Y.K Xu~a B.Liu J.Sun~a K.Liu~a P.P.Shen~b Y.Liu~(a,§) ~a Institute ofm Chemistry,The Chinese Academy of Sciences,Beijing 100080,China Nanjing University,Nanjing,China

【机构】 中国科学院化学研究所分子动态与稳态国家重点实验室；

【摘要】 高等植物光合作用过程中的高传能效率是植物学家多年来十分关切的研究课题。然而,在强光照射下高等植物光系统会发生与活性氧自由基相关的光抑制与光破坏损伤,从而影响了整个光系统的传能效率。更多还原

【Abstract】 One of consistent sources of superoxide photo-induced in the plant systems is the plastoquinone of Photosystem Ⅱ （PSⅡ） complex of thyroid membrane,as indicated in our previous investigations.Here,we further exhibited that both the singlet spin state oxygen and the protonation of semiquinone were prerequisites for the generation of O₂^? in strong illuminated PSⅡ particles.Recently,we comparatively investigated the electron transfer chains in the thyroid membranes of two plants,Aleo and Spinacia oleracea,and superoxide formation therein,and fortunately found a correlation between the photo-induced superoxide generation and the unbalance of two photosystems.The low temperature steady-state fluorescence spectroscopy for Aleo revealed a poor balance of photo quantum between two photosystems.In contrast,the photo-excited electron in PSⅡ can almost totally transfer to PSⅠ of thyroid membrane in Spinacia oleracea.The superoxide concertration in the SOD-free Aleo was obviously stronger than that in the SOD-free Spinacia oleracea.Accordingly,authors propose that the electron which is responsible for the generation of the photo-induced superoxide radicals just leaks from main ET chain between two photosystems.更多还原