EPSPS基因5'端非翻译区串联重复序列介导牛筋草抵抗草甘膦的调控机制

抗草甘膦的牛筋草种群严重威胁着我国农作物的产量与品质，抗性牛筋草种群的扩展将持续影响农作物的安全生产。申请者前期研究发现：抗草甘膦的牛筋草EPSPS基因5’非翻译区串联重复序列（CT）n发生插入突变后，可导致抗性牛筋草植株EPSPS基因的表达显著上调。迄今为止，有关（CT）n序列突变如何调控EPSPS基因表达，并赋予牛筋草对草甘膦产生高抗性的分子机制知之甚少。本申请项目拟采用分子生物学和遗传学等研究方法，首先明确（CT）n序列长度与牛筋草对草甘膦抗性水平的关联性；然后发掘与（CT）n序列结合且调控EPSPS基因表达的转录因子及互作蛋白；最后探寻该转录因子与互作蛋白的生物学特征及功能。以上研究可解析（CT）n序列介导EPSPS基因表达的调控机理，发现杂草对草甘膦产生抗性的新机制。这些研究结果也许能为制定我国绿色治理农田恶性杂草新策略和提升我国绿色农田生态环境质量提供理论依据，应用前景广阔。

Glyphosate- resistant (R) Eleusine indica population seriously threatens the output and quality of crops in China, the expansion of R E. indica will continue to affect the safe production of crops. The applicant's previous study found that the insertion of the (CT)n repeat sequence in the 5′-untranslated region(5’UTR) of the EPSPS gene resulted in a significant up-regulation of EPSPS gene expression in R E. indica. But so far, how the (CT)n sequence regulates the expression of EPSPS gene and conferred E. indica resistance to glyphosate is poorly understood. This project intends to use molecular biology and genetic methods to determine the relationship between the length of (CT)n sequence and the resistant level of E. indica to glyphosate firstly, and then to explore the transcription factor and its interactive protein that bind to (CT)n sequence and regulate the expression of EPSPS gene, and finally to verify the biological functions of the transcription factors and interaction proteins. The above studies will elucidated the regulatory mechanism of (CT)n sequence-mediated expression of EPSPS genes and discover new mechanisms of weed resistance to glyphosate. These findings may provide a theoretical basis for formulating new strategies of farmland weeds control and improving the quality of farmland ecological environment in China, which have a broad application prospect.