抗药性稗草种群严重影响我国水稻的产量和品质。前期研究发现，我国稻田抗性稗草呈现单药抗性向多抗性发展的趋势，但是对于稗草由单抗向多抗性进化的分子调控机制，现阶段知之甚少。申请者拟以来自同一株兼抗二氯喹啉酸和五氟磺草胺的多抗性稗草分离获得并可稳定遗传的稗草多抗性（兼抗二氯喹啉酸和五氟磺草胺）、单抗性（仅抗二氯喹啉酸或五氟磺草胺）和敏感生物型为供试材料。采用组学分析和分子生物学等多学科的研究手段，通过microRNA-mRNA联合分析、microRNA-mRNA靶向关系验证，寻找出调控稗草由单抗向多抗进化的关键microRNA与靶基因；通过供试材料间基因表达特征差异性分析、转基因功能验证，最终挖掘出microRNA参与调控稗草抗二氯喹啉酸和五氟磺草胺的信号通路及其功能特征。研究结果有助于发现稻田稗草种群由单抗向多抗性进化的新机理，为制定我国作物田杂草的绿色防控新策略提供理论依据，应用前景广阔。

Barnyardgrass (Echinochloa crus-galli (L.) Beauv) with herbicide resistance threatens the rice yield and quality seriously in China. Previous studies indicated that the resistance of barnyardgrass in paddy fields tended to evolve from single-resistance to multi-resistance. However, the molecular regulation mechanism of barnyardgrass resistance evolution remains unclear. In this study, four barnyardgrass biotypes (multi-resistant biotype, single-resistant biotypes and susceptible biotype) with similar ecological and genetic backgrounds were segregated from the same barnyardgrass line which develop resistance to both quinclorac and penoxsulam. On this basis, microRNA-mRNA combined analysis and microRNA-RNA targeting relationship validation will be carried out to screen the key microRNAs and target genes regulating barnyardgrass evolution from single- to multi-resistance. Gene expression characteristics analysis and transgenic function verification will be used to excavate the signaling pathways and functional characteristics of microRNAs regulating barnyardgrass resistance to quinclorac and penoxsulam. The results will be helpful to reveal the new mechanism of barnyardgrass evolution from single-resistance to multi-resistance in paddy fields. It will aslo provide scientific theoretical basis for making a new strategy of green prevention and control of weeds in crop fields and has broad application prospects.