秋季粘虫,节食夜蛾(J.E.Smith),是一种广受认可的全球农业害虫,已大大降低了全世界的作物产量。S.frugiperda已经对各种杀虫剂产生了抗药性。昆虫细胞色素P450单加氧酶(CYPs或P450s)在杀虫剂的解毒中发挥重要作用,导致昆虫种群的抗性增加。然而,在水果链球菌中,特定的P450基因对氯氟氰菊酯抗性的功能尚不清楚。在这里,分析了40个P450基因在易感和氯氟氰菊酯抗性种群中的表达模式。其中,发现CYP321A7在抗性群体中过表达,特别是LRS(抗性比率=25.38倍),源自对氯氟氰菊酯敏感的(SS)种群和FLRS(从田间捕获的种群,阻力比=63.80倍)。与SS相比,LRS(2.76倍)和FLRS(4.88倍)观察到细胞色素P450单加氧酶(P450)的酶活性升高,而谷胱甘肽S-转移酶和酯酶的活性没有显着差异。此外,通过RNA干扰敲除CYP321A7基因显著增加了对氯氟氰菊酯的易感性。值得注意的是,CYP321A7的敲除使P450酶活性降低了43.7%,31.9%,SS为22.5%,LRS,和FLRS种群,分别。有趣的是,由于RNA干扰诱导的CYP321A7抑制,用LC30剂量的氯氰菊酯处理的四龄幼虫死亡率更高(增加了61.1%,50.0%,SS为45.6%,LRS,和FLRS种群,分别)。这些发现表明,在S.frugiperda幼虫中,λ-氯氟氰菊酯抗性与CYP321A7的持续过度表达之间存在联系,强调CYP321A7在菊花中的λ-氯氟氰菊酯解毒中的可能重要性。
Fall armyworm, Spodoptera frugiperda (J. E. Smith), is a widely recognized global agricultural pest that has significantly reduced crop yields all over the world. S. frugiperda has developed resistance to various insecticides. Insect cytochrome P450 monooxygenases (CYPs or P450s) play an important role in detoxifying insecticides, leading to increased resistance in insect populations. However, the function of the specific P450 gene for lambda-cyhalothrin resistance in S. frugiperda was unclear. Herein, the expression patterns of 40 P450 genes in the susceptible and lambda-cyhalothrin-resistant populations were analyzed. Among them, CYP321A7 was found to be overexpressed in the resistant population, specifically LRS (resistance ratio = 25.38-fold) derived from a lambda-cyhalothrin-susceptible (SS) population and FLRS (a population caught from a field, resistance ratio = 63.80-fold). Elevated enzyme activity of cytochrome P450 monooxygenases (P450s) was observed for LRS (2.76-fold) and the FLRS (4.88-fold) as compared to SS, while no significant differences were observed in the activities of glutathione S-transferases and esterases. Furthermore, the knockdown of CYP321A7 gene by RNA interference significantly increased the susceptibility to lambda-cyhalothrin. Remarkably, the knockdown of CYP321A7 reduced the enzymatic activity of P450 by 43.7%, 31.9%, and 22.5% in SS, LRS, and FLRS populations, respectively. Interestingly, fourth-instar larvae treated with lambda-cyhalothrin at the LC30 dosage had a greater mortality rate due to RNA interference-induced suppression of CYP321A7 (with increases of 61.1%, 50.0%, and 45.6% for SS, LRS, and FLRS populations, respectively). These findings suggest a link between lambda-cyhalothrin resistance and continual overexpression of CYP321A7 in S. frugiperda larvae, emphasizing the possible importance of CYP321A7 in lambda-cyhalothrin detoxification in S. frugiperda.