除草剂抗药性杂草伴随适合度下降的报道屡见不鲜，但其分子调控机制的认知十分有限。本项目以棒头草乙酰辅酶A羧化酶（ACCase）抑制剂类除草剂的抗性种群为研究对象，前期研究表明该种群的靶标蛋白ACCase发生突变，并伴随适合度下降的现象，具体表现为种子萌发延迟，生长周期缩短，竞争力下降等生物学特性。本项目拟利用转录组学方法，研究靶标基因ACCase突变对种子萌发的分子调控机制。首先，比较棒头草抗性与敏感种群萌发种子的转录组，筛选差异基因，明确潜在目标萌发基因。构建抗性和敏感靶标ACCase基因的转基因拟南芥，明确抗性靶标基因是否直接影响种子萌发，同时构建目标萌发基因及其与抗性和敏感ACCase基因的双表达转基因拟南芥，测定种子萌发率来判断是否目标萌发基因直接或与抗性靶标基因共同作用影响种子萌发。该项目开展将帮助我们深入了解抗性杂草伴随适合度代价的分子机制，为抗性杂草治理提供更合理的解决方案。

Many studies reported that herbicide resistant weed exhibited fitness cost, but the knowledge about the molecular mechanism of the regulation between herbicide target gene and fitness cost is still limited. Our previous study found one Polypogon fugax population which is resistant to acetyl-coA carboxylase (ACCase) herbicides due to an amino acid substitution in ACCase protein. It also exhibited decreased germination ability, shorter life cycle and decreased competition ability compared with the susceptible population. In this project, we will utilize transcriptomic methods to investigate the regulation mechanism between herbicide resistance and seed germination delay. First, we will analysis the transcriptome of germinated seeds of resistant and susceptible P.fugax populations and select the different expressed genes as target germination genes. Meanwhile, we will construct the transgenic Arabidopsis with resistant and susceptible ACCase gene, target germination genes or both of them, and detect the germination ability of these transgenic Arabidopsis seeds to investigate if the germination delay is directly caused by ACCase mutation or regulated by other germination related genes. This project will give us a better understanding of the regulation mechanism of fitness cost in herbicide resistant weed, and provide better solution in weed management and control.