CF 2 -II Alternative Splicing Isoform Regulates the Expression of Xenobiotic Tolerance-Related Cytochrome P450 CYP6CY22 in Aphis gossypii Glover.

The expression of P450 genes is regulated by trans -regulatory factors or cis -regulatory elements and influences how endogenous or xenobiotic substances are metabolized in an organism's tissues. In this study, we showed that overexpression of the cytochrome P450 gene, CYP6CY22 , led to resistance to cyantraniliprole in Aphis gossypii . The expression of CYP6CY22 increased in the midgut and remaining carcass of the CyR strain, and after repressing the expression of CYP6CY22 , the mortality of cotton aphids increased 2.08-fold after exposure to cyantraniliprole. Drosophila ectopically expressing CYP6CY22 exhibited tolerance to cyantraniliprole and cross-tolerance to xanthotoxin, quercetin, 2-tridecanone, tannic acid, and nicotine. Moreover, transcription factor CF 2 -II (XM_027994540.2) is transcribed only as the splicing variant isoform CF 2 -II-AS , which was found to be 504 nucleotides shorter than CF 2 -II in A. gossypii . RNAi and yeast one-hybrid (Y1H) results indicated that CF 2 -II-AS positively regulates CYP6CY22 and binds to cis -acting element p (-851/-842) of CYP6CY22 to regulate its overexpression. The above results indicated that CYP6CY22 was regulated by the splicing isoform CF2-II-AS , which will help us further understand the mechanism of transcriptional adaption of cross-tolerance between synthetic insecticides and plant secondary metabolites mediated by P450s.