New mechanism revealed for light-state transition in cyanobacterium Arthrospira platensis according to 77-K fluorescence kinetics  

作　　者：XU XiuLing ZHANG Rui XIE Jie ZHAO JingQuan 

机构地区：[1]Beijing National Laboratory for Molecular Sciences,Key Laboratory of Photochemistry,Institute of Chemistry,Chinese Academy ofSciences,Beijing 100190,China

出　　处：《Chinese Science Bulletin》2012年第11期1261-1265,共5页

基　　金：supported by the National Natural Science Foundation of China (30970676)

摘　　要：The mechanisms of oxygen evolution and carbon fixation in oxygenic organisms depend on the equal distribution of excitation energy to photosystems Ⅰ and Ⅱ, which is regulated by a mechanism referred to as light-state transition. In this work, a novel mechanism, energy spillover from PS Ⅰ to PS Ⅱ referred to as "inverse spillover", was revealed besides "mobile phycobilisome (PBS)" and the "spillover" of energy from PS Ⅱ to PS Ⅰ in cyanobacteria. Under continuous illumination with blue light, time-dependent 77-K fluorescence spectra demonstrated heterogeneous kinetics for the PBS and photosystem components, indicating that inverse spillover and mobile PBS work successively to regulate the excitation to a balanced distribution in cyanobacterial cells under blue light. Inverse spillover and mobile PBS occur under both 100 and 300 μmol m-2 s-1 blue-light conditions but they are accelerated under the latter.The mechanisms of oxygen evolution and carbon fixation in oxygenic organisms depend on the equal distribution of excitation energy to photosystems I and II, which is regulated by a mechanism referred to as light-state transition. In this work, a novel mechanism, energy spillover from PS I to PS II referred to as ＂inverse spillover＂, was revealed besides ＂mobile phycobilisome （PBS）＂ and the ＂spillover＂ of energy from PS H to PS I in cyanobacteria. Under continuous illumination with blue light, time-dependent 77-K fluorescence spectra demonstrated heterogeneous kinetics for the PBS and photosystem components, indi- cating that inverse spillover and mobile PBS work successively to regulate the excitation to a balanced distribution in cyanobacte- rial cells under blue light. Inverse spillover and mobile PBS occur under both 100 and 300 tmaol m-2 s-1 blue-light conditions but they are accelerated under the latter.

关 键 词：荧光动力学 过渡机制 状态 蓝藻 螺旋藻 均衡分配 时间依赖性 PBS 

分 类 号：Q945.11[生物学—植物学] TN915.04[电子电信—通信与信息系统]