Tang_2020_J.Agric.Food.Chem__

Carboxylesterases (CarEs) are a multigene superfamily of metabolic enzymes involved in metabolic detoxification of xenobiotics. In this study, an alpha-esterase gene (BoalphaE1) was identified from Bradysia odoriphaga. Phylogenetic analysis classified BoalphaE1 into the alpha-esterase clade. Developmental expression analysis indicated that BoalphaE1 was significantly expressed in the second to fourth larval stages. Tissue-specific expression analysis indicated that BoalphaE1 was highly expressed in the larval midgut. After exposure to LC30 of malathion, the CarE activity of B. odoriphaga was induced and the transcriptional level of BoalphaE1 was significantly up-regulated. Silencing of BoalphaE1 significantly increased the susceptibility of B. odoriphaga larvae to malathion. Inhibition assays in vitro indicated that malathion significantly inhibited BoalphaE1 activity. GC-MS assay showed that BoalphaE1 possesses hydrolase activity toward malathion and participates in the detoxification of malathion. These results strongly suggest that BoalphaE1 plays a crucial role in detoxification of malathion in B. odoriphaga.