水稻P450s和GSTs在氯乙酰胺类除草剂代谢中的联合作用机理研究

水稻的除草剂药害是目前我国农业生产中亟待解决的科学问题，水稻体内解毒酶GSTs在氯乙酰胺类除草剂的代谢中发挥着重要功能，但目前人们对P450s和GSTs的联合作用机理知之甚少。本项目拟在前期研究的基础上，采用酶活性检测和蛋白质SDS-PAGE法，首先明确氯乙酰胺类除草剂及解草啶对水稻体内P450s和GSTs的诱导机制；然后通过离体试验结合LC-MS等检测技术分析这两类酶单独或联合催化氯乙酰胺类除草剂降解的效果；并用放射性薄层色谱法（RTLC）、HPLC、LC-MS鉴定水稻体内放射性标记的氯乙酰胺类除草剂的代谢产物，结合离体降解效果推导该类除草剂在水稻体内可能的代谢途径；最后利用P450s和GSTs抑制剂进一步确证两类酶在氯乙酰胺类除草剂代谢中的作用。旨在阐明氯乙酰胺类除草剂在水稻体内的代谢机理，为提高该类除草剂对水稻的安全性提供理论依据。

The herbicide phytotoxicity to rice is an emergent scientific problem to be resolved for agricultural production in our country. It is known that GSTs in rice play an important role in metabolism of chloroacetamide herbicide, but the mechanism of synergistic herbicide metabolism between P450s and GSTs is quite unclear. On basis of our preliminary studies, the enzyme acitivity assay and SDS-PAGE will be applied firstly to discover the induction mechanism of P450s and GSTs induced in rice by chloroacetamide herbicides and fenclorim. Then LC-MS will be applied to analyze the degradation of chloroacetamide herbicides catalyzed by P450s and GSTs respectively or jointly in vitro. The RTLC, HPLC and LC-MS will be applied to identify the metabolites of radiolabeled chloroacetamide herbicides in rice,combining with the results in vitro,to deduce the possible metabolic pathway of chloroacetamide herbicides. At last, inhibitors of GSTs and P450s will be used in rice to confirm the the effects of GSTs and P450s in metabolizing chloroacetamide herbicides in rice. The purpose of this project is to elucidate the metabolism mechanism of chloroacetamide herbicides in rice，which will provide theoretical instructions for improving the safety of this type of herbicides to rice.