乙醇酸氧化酶（Glycolate oxidase，GLO）催化乙醇酸生成乙醛酸并伴随等量H2O2产生，其在植物光呼吸、光合过程以及逆境响应过程中均发挥着重要作用。申请人先前研究证实水稻中由GLO1与GLO4共同编码五种GLO同工酶，且GLO与过氧化氢酶（CAT）存在互作与解离机制，该机制可调节CAT对光呼吸H2O2的清除速率，进而调节细胞内H2O2水平。进一步的研究发现，GLO-CAT互作与解离及GLO同工酶组成形式可能受到GLO糖基化的调控，但其具体机理还不清楚。本项目拟在前期研究基础上鉴定水稻GLO糖基化位点；研究GLO糖基化修饰对GLO与CAT互作及GLO同工酶谱组成的调控作用；进一步解析糖基化调控互作对光呼吸乙醇酸-H2O2代谢的调节作用，探讨其在逆境响应相关H2O2信号转导中的作用。该研究即有助于加深对H2O2信号发生转导机理的认识，还对进一步利用分子生物学手段改善作物耐逆性具有重要实际意义。

Glycolate oxidase (GLO) is a key enzyme in photorespiratory metabolism. Increasing evidences indicate that GLO is not only involved in the regulation of photorespiration and photosynthesis, but also plays functional roles in biotic or abiotic stress resistance. Our previous studies have suggested that five GLO isozymes with different catalytic properties are coordinately controlled by GLO1 and GLO4 in rice, recently further revealed that the association-dissociation of GLO with catalase (CAT) in rice could be a potential switch to modulate intracellular H2O2 levels. The glycosylation of GLO may influence the interaction of GLO and CAT and the GLO isoenzyme patterns, but the mechanism in this respect remains unclear. In this study, we intend to identify the glycosylation site of GLO, and analyze the influence of GLO glycosylation on the interaction between the GLO subunits or GLO and CAT. In addition, shall further investigate the role of GLO glycosylation in the glycolate-H2O2 metabolism. Finally, the physiological function of GLO glycosylation in the H2O2-mediated signal transduction will be evaluated. The results through this study will not only be helpful for our understanding of the regulation of H2O2-mediated signal transduction, but also of practical significance when we will be able to use molecular and biotechnological approaches to improve crop stress resistance through regulating H2O2 signaling generation.