Identification and characteristic analysis of the catalase gene from Locusta migratoria

Catalase (CAT) is a ubiquitous antioxidant enzyme in almost all living organisms exposed to atmosphere, which involved in decomposing harmful hydrogen peroxide, into oxygen and water. In this study, a full-length cDNA (1524bp) encoding the catalase gene (LmCAT) from Locusta migratoria was cloned (accession number KT716445). The open reading frame of the LmCAT gene encoded 507 amino acids and shared 57.8%-97.8% amino acid identities with other insect CATs. The coding region was interrupted by 9 introns, while its promoter region contained 15 putative binding sites for 5 kinds of transcriptional regulation factors. For the stage-specific expression profile, LmCAT was highly expressed in the fourth-instar nymphs. For the tissue-specific expression profile, the LmCAT transcripts were highest in the fat bodies, and relatively abundant in the gastric caecum, Malpighian tubules, ovary and integument. Moreover, the result showed that quercetin could significantly induce the expression level of LmCAT. The expression of LmCAT could be silenced by RNAi, but the moralities were not significantly different between control and RNAi groups. Our results would provide valuable information for further study on the ROS regulation mechanism in insect.