Kinetics of blue-green light-induced state transition and fluorescence quenching in the wild-type cyanobacterium Synechocystis PCC 6803 and apc D2 and apc F2 mutants  

作　　者：Wenfeng Zhao Jie Xie Jingquan Zhao 

机构地区：[1]Beijing National Laboratory for Molecular Sciences (BNLMS),CAS Key Laboratory of Photochemistry, Institute of Chemistry,Chinese Academy of Sciences

出　　处：《Chinese Science Bulletin》2014年第34期4712-4719,共8页

基　　金：supported by the Chinese Academy of Sciences(KJCX2-YW-W25)

摘　　要：State transition and blue-green light-induced fluorescence quenching are two short-term processes in cyanobacteria. The details of their kinetics and the relationship between these processes have not been elucidated.In this work, these two processes were studied in the wildtype cyanobacterium Synechocystis PCC 6803 cells as well as in apc D-and apc F-mutants by monitoring their timedependent 77 K fluorescence responses to blue-green light(430–540 nm) at a series of intensities ranging from20–800 l E m-2s-1. The lowest light intensity to induce fluorescence quenching in wild-type cells was160 l E m-2s-1under the selected experimental conditions, while state transition took place at the intensities lower than 160 l E m-2s-1at a conservative level, but at variable rates. The quenching level increased at intensities higher than 160 l E m-2s-1, reaching the maximum level at intensities equal to or higher than 200 l E m-2s-1.Fluorescence kinetics indicated that both the length of the induction period and time required to reach the maximum level were functions of light intensity. State transitions as well as fluorescence quenching took place in both wildtype and mutant cells, but might involve different mechanisms.State transition and blue-green light-induced fluorescence quenching are two short-term processes in cyanobacteria. The details of their kinetics and the relationship between these processes have not been elucidated. In this work, these two processes were studied in the wildtype cyanobacterium Synechocystis PCC 6803 cells as well as in apcD^- and apcF^- mutants by monitoring their time- dependent 77 K fluorescence responses to blue-green light （430-540 nm） at a series of intensities ranging from 20-800 μE m^-2 s^-1. The lowest light intensity to induce fluorescence quenching in wild-type cells was 160 μE m^-2 s^-1 under the selected experimental conditions, while state transition took place at the intensities lower than 160 μE m^-2 s^-1 at a conservative level, but at variable rates. The quenching level increased at intensities higher than 160 μE m^-2 s^-1, reaching the maximum level at intensities equal to or higher than 200 μEm^-2 s^-1. Fluorescence kinetics indicated that both the length of the induction period and time required to reach the maximum level were functions of light intensity. State transitions as well as fluorescence quenching took place in both wildtype and mutant cells, but might involve different mechanisms.

关 键 词：荧光动力学 状态转换 野生型 光诱导 突变体 PCC 集胞藻 蓝绿色 

分 类 号：Q942[生物学—植物学]