水稻CAT与逆境应答关系及酶活性分析

Isoenzyme of Catalase(CAT) in Rice in Response to Stresses and the Enzymes Activity

过氧化氢酶(catalase,CAT)是一种四聚体血红素酶,主要存在于过氧化物酶体与乙醛酸循环体及相关细胞区域内。水稻中含有CAT1、CAT2和CAT3三种主要同工酶。它们在各组织不同的发育阶段,发挥着重要作用。在本研究解析了水稻过氧化氢酶同工酶基因在NaCl、NaHCO3、Na2CO3、PEG6000、H2O2、低温等逆境处理下mRNA表达特性。结果表明在不同的逆境下过氧化氢酶同工酶在表达上存在差异性。同时利用蛋白表达系统,对水稻过氧化氢酶CAT1和CAT3蛋白进行了纯化实验,对纯化的蛋白的酶活性分析的结果表明,CAT1和CAT3的酶活性没有十分显著的差别。

Catalase is a potent antioxidant enzyme that catalyzes the conversion of H2O2 to oxygen and water. Plants have evolved multiple isoforms of catalase that are differentially regulated in various tissues during development, and by a variety of environmental stresses. In this study, we analyzed the differentiation of the isoenzyme of catalase in rice mRNA expression level by time under abiotic stress （100 mmol/L NaCl, 30 mmol/L NaHCO3, 15 mmol/L Na2CO3, 10% PEG6000, 10% H2O2, low temperature） by RT-PCR. Denaturation, renaturation and purification of the inclusionbodies from CAT, and CAT3 was carried out by QIAexpress System. We obtained the protein with biological activities.