光氧化胁迫条件下叶绿体中活性氧的产生、清除及防御

摘要

Reactive oxygen has a dual function that it damages cells at high concentrations and protects cells at low concentrations.Under photo-oxidative stress,the highly energetic reactions in photosynthesis,along with sufficient oxygen supply,makes chloroplasts a particularly abundant source of reactive oxygen species.Once reactive oxygen species accumulated under photo-oxidative stress to a certain amount that the antioxidant systems in chloroplasts cannot get rid of,it may irreversibly damages chloroplasts and cells.However,the plastids in higher plants are the semi-autonomous organelles that have their own genome and transcription and translation mechanisms to control the formation of reactive oxygen species and prevent photosynthetic bodies from photo-oxidation damage.Therefore,the paper reviews and discusses the formation,functions and protective mechanisms of reactive oxygen species.%活性氧(ROS)具有双重作用,高浓度引起细胞损伤,低浓度起保护作用.在光氧化胁迫条件下,光合作用高能态的反应与O2丰富供应使叶绿体成为活性氧丰富的来源.当ROS的积累超过抗氧化剂防护系统清除能力,叶绿体及细胞不可逆的光氧化损伤就会出现.而高等植物的质粒是半自主的细胞器,有它们自己的基因组学及转录、翻译机制来控制ROS生成、保护光合作用机构免受光氧化损伤. 因此,本文就光氧化胁迫期间,叶绿体中ROS的生成、功能与防护机制进行了综述.