CPR和P450基因在昆虫抗药性中的作用研究进展

P450酶系在昆虫代谢农药中有重要作用，NADPH-细胞色素P450还原酶（NADPH-cytochrome P450 reductase，CPR）和细胞色素P450（P450）在该酶系起核心作用。昆虫具有P450超基因家族，但只有一个单一的CPR基因，CPR是昆虫所有参与农药代谢的P450酶的唯一电子供体，其影响P450活性。P450基因的高水平表达在害虫抗药性中具有重要作用，P450基因介导的昆虫抗药性是最重要的代谢抗性类型。不同P450基因的高表达的调控机制不同，引起P450基因过量表达的原因可能有P450基因的编码区突变、顺式作用元件和反式作用因子变化、基因扩增等。细胞色素P450介导的抗药性存在一定程度的进化可塑性，即同种昆虫不同种群对相同的农药产生抗药性时，导致抗性产生的P450基因不同；同一昆虫品系在某种农药的抗性选择压力下，影响抗性的P450基因的种类和表达特性会随着持续的农药选择而发生变化。最近的研究显示，CPR的变异和昆虫抗药性相关，但是昆虫CPR基因介导抗药性的机制还缺乏深入研究。全面阐释P450酶系介导昆虫抗药性的机制、建立基于P450基因表达量变化与CPR突变的抗性分子标记，对于害虫抗药性治理具有重要意义。

The roles of CPR and P450 genes in the resistance of insects to insecticides

The cytochrome P450 monooxygenase (P450) system is involved in the detoxification and metabolism of insecticides in insects. NADPH-cytochrome P450 reductase (CPR) and the cytochrome P450 monooxygenases (P450s) are the main and key parts of the system. P450 is a super gene family, whereas there is only one CRP gene in insects. CPR is the only electron donator of all insect P450s that metabolize insecticides, and affects the activity of the P450s. The overexpression of P450 genes play important role in insecticide resistance of insects. The regulation mechanisms for P450 gene overexpression varied in different insects, including mutation in gene coding region, trans-regulation, cis-regulation, gene amplification and so on. There is evolutionary plasticity for P450-mediated insecticide resistance, i.e., varied P450 genes could contribute to the resistance of different populations of one insect species to a same insecticide; P450 gene expression pattern and gene type could change in a insect species under the a insecticide selection pressure. Previous reports have found that CPR is a vital part of P450-mediated insecticide resistance, but the mechanisms are not known. The comprehensive understanding of mechanisms for the P450-mediated insecticide resistance as well as the development of molecular markers for insecticide resistance monitoring based on the P450 gene expression and CPR gene mutations is important for insecticide resistance management of pest insects.