Expression responses of nine cytochrome P450 genes to xenobiotics in the cotton bollworm Helicoverpa armigera

Cytochrome P450s play a crucial role in insect adaptation to their host plants and in insecticide resistance through metabolic detoxification. The efficacy of P450 mediated detoxification depends on the levels of P450 transcript which may change after exposure to xenobiotics. In this study, expression response of nine cytochrome P450 genes in Helicoverpa armigera, belonging to CYP6 and CYP9 families, were examined by using quantitative real-time PCR method. Results showed that these cytochrome P450 genes were differentially affected by plant chemicals and synthetic compounds, and displayed tissue-, concentration- and inducer-dependent response. Phenobarbital acted as a general inducer for cytochrome P450s, whereas gossypol specifically increased the expression of CYP6AE14. Xanthotoxin showed moderate induction effect on several of the nine genes. Deltamethrin displayed significantly both induction and suppression impact on the expression of cytochrome P450s. These findings provide clues for further elucidating the function and regulation mechanism of these cytochrome P450 genes in H. armigera, a pest responsible for severe losses in many crops.