The relationship between superoxide and singlet oxygen in PSⅡ particle of spinach under strong illumination was studied with spin-trap ESR technique. The generation of superoxide was increased under D2 environment which prolonged the half life of singlet oxygen. The generation of superoxide was decreased when histidine existed as a scavenger of singlet oxygen. It is highly possible that the superoxide generated in PSⅡ particle originates from singlet oxygen.
刘科1孙健1,2徐英凯1 陈中伟1 张启元1 张兴康1 匡廷云2 刘扬1*
（1. 中国科学院化学研究所，北京100080；2. 中国科学院植物研究所，北京100093）