Overexpression of multiple cytochrome P450s contributed to resistance to sulfoxaflor and acetamiprid in different geographical populations of Aphis gossypii

Abstract

Abstract Aphis gossypii is a destructive pest of cotton, and its serious insecticide resistance is an important threat to the safe production of cotton in Xinjiang. To investigate the differences in resistance mechanisms of cotton aphid to sulfoxaflor and acetamiprid in different geographical regions, the sulfoxaflor- and acetamiprid-resistant strains of cotton aphids from Yarkant and Jinghe were established indoors (Yarkant sulfoxaflor-resistant strain: RR = 43.12-fold, Yarkant acetamiprid-resistant strain: RR = 39.77-fold, Jinghe sulfoxaflor-resistant strain: RR = 40.77-fold, Jinghe acetamiprid-resistant strain: RR = 34.16-fold). The synergist and activity of detoxification enzyme assays showed that the resistance to sulfoxaflor and acetamiprid in cotton aphids from Yarkant and Jinghe was associated with the increase of P450s activity. Transcriptome analysis showed that 11 P450 genes were differentially expressed in sulfoxaflor- and acetamiprid-resistant strains in Yarkant and Jinghe (|log2 Fold change| ≥ 1 and P-value < 0.05), and their expression varied not only among different resistant strains but also among different cotton aphid populations. The function of overexpression genes CYP380C45, CYP380C46, CYP6CY13, CYP6DC1 and CYP6CY24 involved in resistance were further validated by using RNAi. Knockdown of CYP380C45 of cotton aphids in all resistant strains could increase the sensitivity to sulfoxaflor or acetamiprid. Silencing of CYP6DC1 and CYP380C46 expression increased the sensitivity of cotton aphids to sulfoxaflor or acetamiprid in Yarkant and Jinghe resistant strains respectively. And the knockdown of CYP6CY13 increased the sensitivity of Yarkant sulfoxaflor resistant strain to sulfoxaflor, the knockdown of CYP6CY24 increased the sensitivity of Jinghe sulfoxaflor resistant strains to sulfoxaflor. These results indicate that the resistance of cotton aphids to sulfoxaflor and acetamiprid is mediated by several P450 genes, and the changes of P450 genes expression in resistant strains various in different geographical cotton aphid populations and different selected type of insecticides.