三氟苯嘧啶抗性灰飞虱细胞色素P450 CYP4CE2基因的过量表达调控机制

由转录因子和顺式调控元件调控的细胞色素P450基因过量表达是昆虫对杀虫剂产生抗性的重要机制。前期研究发现，三氟苯嘧啶抗性灰飞虱品系中的P450基因CYP4CE2明显过量表达，RNAi沉默该基因显著提高抗性灰飞虱的药剂敏感性，推测CYP4CE2基因在灰飞虱对三氟苯嘧啶抗性形成中起到重要作用，但其表达调控机制尚不清楚。本研究拟通过体外异源表达、HPLC-MS、基因组步移、RT-qPCR、双荧光素酶报告实验和RNAi等技术，验证灰飞虱CYP4CE2基因对三氟苯嘧啶的代谢功能，筛选和鉴定CYP4CE2基因的顺式调控元件和转录因子，明确转录因子/顺式调控元件对CYP4CE2基因的表达调控机制，阐明CYP4CE2基因过量表达在灰飞虱对三氟苯嘧啶产生抗性中的作用。研究结果不仅对丰富昆虫P450基因的解毒代谢功能和表达调控机制具有重要理论意义，对于田间灰飞虱对三氟苯嘧啶的抗性延缓和治理也有重要应用价值。

The overexpression of cytochrome P450 gene in insects is the important insecticide resistant mechanism, in which the up-regulation of resistance P450 genes is regulated by transcription factors and/or cis-elements. Recently we have found that the CYP4CE2 gene showed higher expression in triflumezopyrim-resistant strain compared with the susceptible strain of Laodelphax striatellus, silencing of CYP4CE2 by RNAi significantly increased the susceptibility of the resistant strain to triflumezopyrim. So the CYP4CE2 gene may responsible for the majority of triflumezopyrim resistance to L. striatellus, but the regulation expression mechanisms are still unclear. The techniques including RNAi, HLC-MS, functional expression of CYP4CE2 protein, genome walking, RT-qPCR and dual-luciferase reporter system will be used to confirm the capability of CYP4CE2 to degrade triflumezopyrim, identify the triflumezopyrim responsive transcription factors and cis-elements of CYP4CE2, understand the regulatory mechanisms of CYP4CE2 by transcription factors / cis-elements , clarify the function of overexpression of CYP4CE2 gene conferring the metabolic resistance of L. striatellus to triflumezopyrim. The expected results will help us to deep understand the theory in detoxification metabolic function and regulation expression mechanisms of insects P450 gene, and provide important application basis to prevent or control the resistance of L. striatellus to triflumezopyrim in field.