A Comparative Study of Transcriptional Regulation Mechanism of Cytochrome P450 CYP6B7 between Resistant and Susceptible Strains of Helicoverpa armigera

Abstract

Cytochrome P450 CYP6B7 has previously been proved to be associated with fenvalerate-resistance in Helicoverpa armigera. Here, how CYP6B7 is regulated and involved in the resistance of H. armigera is studied. Seven base differences (M1−M7) were found in CYP6B7 promoter between a fenvalerate-resistant (HDTJFR) and a susceptible (HDTJ) strain of H. armigera. M1− M7 sites in HDTJFR were mutated into the corresponding base in HDTJ, and pGL3-CYP6B7 reporter genes with different mutation sites were constructed. Fenvalerate-induced activities of reporter genes mutated at M3, M4, and M7 sites were significantly reduced. Transcription factors Ubx and Br, whose binding sites contain M3 and M7, respectively, were overexpressed in HDTJFR. Knockdown of Ubx and Br results in significant expression inhibition of CYP6B7 and other resistance-related P450 genes, and increase of sensitivity of H. armigera to fenvalerate. These results indicate that Ubx and Br regulate the expression of CYP6B7 to mediate the fenvalerate-resistance in H. armigera.

Enthralling genetic regulatory mechanisms meddling insecticide resistance development in insects: role of transcriptional and post-transcriptional events

“…pGL3-CYP6B7 reporter genes with varied mutation sites revealed that genes with M3, M4, and M7 mutations had significantly lower fenvalerate-induced activity. The transcription factors Ubx and Br were over-expressed in HDTJFR, with binding sites containing M3 and M7, respectively, confirming their role in fenvalerate resistance in Helicoverpa armigera ( Huang et al, 2023 ).…”