Identification and expression profiles of putative cytochrome P450 monooxygenase genes from Cnaphalocrocis medinalis (Lepidoptera: Pyralidae)

In insects, cytochrome P450 monooxygenases (P450s) have received considerable attention for their roles in the detoxification of harmful chemicals and insecticide resistance. The rice leaf-folder, Cnaphalocrocis medinalis, is a severe lepidopteran rice pest. In this research, 36 putative P450 genes were identified from the transcriptome dataset of C.medinalis. Phylogenetic analysis showed that these genes fell into four clans, including the mitochondrial clan (6 genes), CYP2 clan (5 genes), CYP3 clan (16 genes) and CYP4 clan (9 genes), and were classified into 19 families and 30 subfamilies. Since the CYP6 P450 family in insects is the major family related to the detoxification of xenobiotics, the expression profiles of five genes in the CYP6 family were determined by real-time quantitative PCR. These genes were differentially expressed in various larval tissues, including the midgut, Malpighian tubules and fat body. Of these, CYP6AW1 and CYP6CV1 were mainly expressed in the midgut, while CYP6AE76 was highly expressed in the fat body. CYP6AB62 and CYP6AE28 were ubiquitously expressed. The transcription of CYP6AE28 was significantly induced by abamectin at LD20 dose. Taken together, the results provided useful information for the characteristics of P450s in C.medinalis and for future functional studies.