烟粉虱噻虫嗪抗性基因CYP4C64转录因子调控机制研究

Pests are difficult to control mainly because of pesticides resisitance, and the mechanism of insecticide resistance is the basis of pest management. Neonicotinoid insecticide thiamethoxam have been widely used to control a serious agricultural pest Bemisia tabaci in many countries. However, field Bemisia tabaci populations have developed resistance to thiamethoxam, and there is still lack of research on factors that the resistance and regulation mechanism of Bemisia tabaci to thiamethoxam. Base on this scientific issue, previous studies of RNA-seq, qRT-PCR and RNA interference were carried out and the results exhibited that an over-expressed cytochrome P450 gene CYP4C64 plays a very important role in thiamethoxam resisance. In this study intends to use the methods of dual-luciferase reporter gene system; EMSA; CHIP and RNAi to study the transcription factor regulation mechanism of CYP4C64 in Bemisia tabaci. Our expected results will reveal the regulation mechanism of thiamethoxam resistance, and provide a basis for research on the response pathway of both endogenous and xenobiotic substances, and therefore provide a theoretical significance to further establish the IPM strategies for whiteflies.

害虫抗药性是导致其难以防治的主要原因，抗药性的形成机制研究是害虫治理的基础。新烟碱类杀虫剂噻虫嗪广泛用于世界性农业害虫烟粉虱的防治，但是田间烟粉虱已经产生严重的抗药性，而人们对噻虫嗪抗性的形成机制却知之甚少。针对这一科学问题，本课题组前期进行了转录组测序，荧光定量PCR，RNA干扰等研究，结果表明细胞色素P450基因CYP4C64过量表达在烟粉虱对噻虫嗪抗性形成过程中发挥重要的作用。本研究在此基础上拟采用双荧光素酶报告基因检测系统、EMSA、CHIP以及RNA干扰等技术手段，深入研究烟粉虱CYP4C64基因转录因子水平的调控机制。预期研究结果将有助于揭示P450介导的烟粉虱对噻虫嗪抗性形成的分子调控机制，为今后深入开展烟粉虱对噻虫嗪等外源物质的信号响应途径研究提供理论基础，也为制定烟粉虱的综合治理对策提供理论依据。

烟粉虱是一种世界性危严重的农业害虫，杀虫剂噻虫嗪广泛用于烟粉虱的防治，但是田间烟粉虱已经产生严重的抗药性，而人们对噻虫嗪抗性的形成机制却知之甚少。针对这一科学问题，通过前期研究发现胞色素P450基因CYP4C64过量表达在烟粉虱对噻虫嗪抗性形成过程中发挥重要的作用，本研究通过Western blot, RNAi和转基因果蝇等一系列分子生物学方法详细验证CYP4C64在烟粉虱噻虫嗪抗性形成中的作用，结果表明CYP4C64基因的过量表达导致烟粉虱产生噻虫嗪抗性。并且通过项目研究发现转录因子E63参与CYP4C64基因表达调控。进一步通过深入探索研究发现CYP4C64基因5’ UTR区域的点突变与抗性形成有关，并且该突变位点影响了m6A甲基化酶对该基因表达调控的作用，首次从表观遗传学角度发现转录后修饰影响昆虫对人工合成杀虫剂的抗药性形成机制。研究结果将有助于揭示P450介导的烟粉虱对噻虫嗪抗性形成的分子调控机制，为今后深入开展烟粉虱对噻虫嗪等外源物质的信号响应途径研究提供理论基础，也为制定烟粉虱的综合治理对策提供理论依据。