叶绿体光合代谢中活性氧的产生与清除

摘要

有氧代谢不可避免产生活性氧(ROS),叶绿体的PSⅠ和PSⅡ反应中心均是ROS产生的主要位点.叶绿体产生的ROS主要有超氧阴离子(O2-)、过氧化氢(H2O2)、羟自由基(·OH)和单线氧(1O1),其中在PSI产生的O2-将进一步产生H2O2和·OH,而1O2产生在PSⅡ.正常生理代谢条件下,叶绿体内抗氧化系统和光能吸收利用的调节保持活性氧产生和消灭的平衡,不会影响植物的正常生理功能.%Aerobic metabolism inevitably products the reactive oxygen species ( ROS) in chloroplasts , and the reaction centers of PSⅠ and PSⅡ in chloroplast thylakoids are the major generation sites of ROS. ROS from chloroplasts mainly include superoxide anion ( O2- ) , hydrogen peroxide ( H2O2) , singlet state oxygen (1O2) and hydroxy radical ( · OH) . Both · OH and H2O2origin from O2- in PSⅠ, however, 1O2generate in PSⅡ. In normal physiological conditions, the production and scavenging of ROS maintains balance, and will not affect the plant's physiological function by regulating antioxidant system, absorption and elimination of light.