Functional analyses of genes conferring insecticide resistance and their application in control of Plutella xylostella

小菜蛾对拟除虫菊酯的抗性主要是由于降解酶代谢解毒增加和靶点敏感性降低所致。对钠通道的氨基酸序列分析表明，该通道上的三个点突变(L1014F、T929I和M918I)和两个多态(A1101T和P1879S)与拟除虫菊酯抗性有关。T929I位点由两个互斥的外显子(18a和18b)编码，含有18b的剪接变异体以组织特异性方式表达。对CYP6BG1的表达和钠通道突变的分析表明，这两种抗性机制都独立地参与了田间小菜蛾对拟除虫菊酯的抗性。

Pyrethroid resistance of the diamondback moth Plutella xylostella is mainly conferred by increased metabolic detoxification of the degradation enzymes and decreased sensitivity of the target site. Analysis of amino acid sequences of the sodium channel showed that three point mutations (L1014F, T929I and M918I) and two polymorphisms (A1101T and P1879S) on the channel are involved in the pyrethroid resistance. The T929I site was encoded by two mutually exclusive alternative exons (18a and 18b) and the splice variant containing 18b was expressed in a tissue specific manner. Analysis of the CYP6BG1 expression and the sodium channel mutations showed that both resistance mechanisms are independently involved in pyrethroid resistance of the diamondback moth in the field.