Response of P450 gene of Frankliniella occidentalis (Thysanoptera: Thripidae) in succession adaptation to broad bean plant

In insects, cytochrome P450 (CYP), an important detoxification enzyme, is crucial in host plant adaptation. In this study, we discerned the alterations in the expression of CYP genes in western flower thrips (WFT; Frankliniella occidentalis) in developing adaptation to broad bean plants. The alterations in the expression levels of CYP4 and CYP6 were examined after transferring the WFT reared on kidney bean pods (control) to broad bean plants and rearing for three generations (treatments). The findings showed that CYP6-2 in 2nd instar nymphs, CYP4-3, and CYP6-2 in adults were significantly upregulated in the F₁ generation, while other genes did not show significant changes. Furthermore, in the F₂ 2nd instar nymphs, most CYP genes were highly expressed, whereas, in the F₂ and F₃ generations, four CYP4 and two CYP6 genes in the 2nd instar nymphs and five CYP4 and three CYP6 genes in the adults showed a similar level of expressions. These results revealed that expression of P450 genes in WFT was related to their developmental stages and adaptive generations. Overall, the study provides insights into the understanding of the evolution of host adaptability of WFT and could assist in the integrated control of WFT.