小麦是我国重要粮食作物，菵草是我国小麦田恶性杂草，精噁唑禾草灵是防除小麦田禾本科杂草的重要药剂，目前抗性严重。本课题组已在多地发现抗精噁唑禾草灵菵草种群，抗性水平达到高抗，靶标抗性机理已明确，且存在代谢抗性。为了明确细胞色素P450氧化酶、氧化酶、酯酶、水解酶、过氧化氢酶、谷胱甘肽硫转移酶、糖基转移酶及转运蛋白八大代谢酶家族在抗性中的作用及机理，本课题拟通过转录组测序结合RT-PCR和RACE技术，分离菵草八大代谢酶家族的基因，建立菵草代谢酶家族基因库，研究基因库中基因的mRNA表达水平，明确抗性菵草对精噁唑禾草灵胁迫响应的表达模式，克隆基因库中基因，比对基因序列，确定抗性与敏感菵草基因结构差异，挖掘出与抗性相关的代谢酶基因，解析菵草抗精噁唑禾草灵的代谢酶分子机理。本研究既能补充杂草代谢抗性理论，又能指导抗性菵草的科学防除，延缓抗性发展，有利于实现农业增产、农民增收的根本目的。

Wheat is an important crop in China. Beckmannia syzigachne is a serious gramineous weed in wheat fields in China. Fenoxaprop-P-ethyl is one of the most widely used aryloxyphenoxypropionate herbicides (AOPPs) in China to control annual gramineous weeds in wheat fields. However, its controlling efficiency has been decreasing with the contiuous application in fields. We collected several B. syzigachne populations with high resistance to fenoxaprop-P-ethyl. Mechanisms of target site resistance have been clarified, while those of metabolic resistance have been confirmed in these populations and are still unclear. In order to reveal the effects and mechanisms about eight metabolizing enzyme families (cytochrome P450s, esterases, hydrolases, oxidases, peroxidases, glutathione-S-transferases, glycosyltransferases and transporter proteins) in fenoxaprop-P-ethyl-resistant B. syzigachne, we propose to (1) build the gene bank of the metabolizing enzyme families, by isolating the genes of the eight metabolizing enzyme families with transcriptome sequencing and de novo assembly, combined with RT-PCR and RACE; (2) illuminate the expression patterns of these genes in response to fenoxaprop-P-ethyl in fenoxaprop-P-ethyl-resistant B. syzigachne populations employing Real-time PCR; (3) identity the differences in genetic structures of these genes between the sensitive and resistant B. syzigachne, by cloning and comparing relative gene sequences. Then, the metabolizing enzyme genes related to fenoxaprop-P-ethyl-resistance will be confirmed and metabolic resistance mechanisms will be analyzed. The results of this project will help us understand the mechanism of metabolic herbicide-resistance, provide key information to the management of weeds with metabolic resistance, and thus are significant for increasing agricultural production and farmer incomes.