Identification of cis-acting elements in response to fenvalerate in the CYP6B7 promoter of Helicoverpa armigera

Cytochrome P450-mediated detoxification plays an important role in the development of insecticide resistance . Previous studies have shown that cytochrome P450 CYP6B7 was induced by fenvalerate and involved in fenvalerate detoxification in Helicoverpa armigera . However, the transcriptional regulation of CYP6B7 induced by fenvalerate remains unclear. Here, a series of progressive 5′ deletions of CYP6B7 promoter reporter genes were constructed, and the relative luciferase activities were detected. The results revealed that the relative luciferase activity of plasmid p (−655/−1) was significantly induced by fenvalerate. Further deletion of the region between −655 and −486 bp showed that the highest luciferase activity induced by fenvalerate was observed in plasmid p (−528/−1), while p (−485/−1) had the lowest fenvalerate-induced luciferase activity. Moreover, internal deletion and mutation in the region between −508 and −486 bp resulted in a significant reduction in fenvalerate-induced CYP6B7 promoter activity, suggesting that the cis -acting element responsible for fenvalerate in the CYP6B7 promoter was located between −508 and −486 bp. These results promote an understanding of the expression regulation mechanism of P450 genes that conferring resistance to insecticides .