Resistance mechanisms of the diamondback moth against various insecticides

本研究对乙酰甲胺磷敏感性不同的小菜蛾（Plutella xylostella）品系的乙酰胆碱酯酶1基因（AChE1）进行了分析。在野外收集的菌株中发现了该基因的多个单倍型，包括携带一个或两个先前报道的突变（A298S和G324A）的不同单倍型。此外，测序结果表明，在现场收集的菌株中存在重复的基因拷贝。乙酰胆碱酯酶1的拷贝数和乙酰甲胺磷的抗性水平之间没有发现相关性，这表明广泛的乙酰胆碱酯酶1重复至少在一些小菜蛾菌株中不是主要的抗性因素。A298S和G324A突变的比例与乙酰甲胺磷抗性水平无关。这表明小菜蛾对乙酰甲胺磷的抗性是复杂的，不能仅根据AChE1的拷贝数或抗性突变的比例进行评估。

This study examined the acetylcholinesterase 1 gene (AChE1) in Plutella xylostella strains with different sensitivities to acephate. Multiple haplotypes of the gene were found in the field-collected strains including distinct haplotypes carrying one or both previously reported mutations (A298S and G324A). Moreover, sequencing results indicated the presence of duplicated copies of the gene in the fieldcollected strains. No correlation was found between copy numbers of AChE1 and levels of resistance to acephate suggesting that extensive AChE1 duplication is not a major resistance factor at least in some P. xylostella strains. Proportions of the A298S and G324A mutations showed no correlation with levels of resistance to acephate. This suggests that acephate resistance of P. xylostella is complex and cannot be evaluated based on the AChE1 copy number or proportions of the resistance mutations alone.