Characterization of the insecticide detoxification carboxylesterase Boest1 from Bradysia odoriphaga Yang et Zhang (Diptera: Sciaridae)

Abstract

BACKGROUND: In insects, carboxylesterases (CarEs) are enzymes involved in the detoxification of insecticides. However, the molecular mechanism of CarE-mediated insecticide metabolism in Bradysia odoriphaga, a serious agricultural pest, remains unclear. The aim of this study is to investigate the detoxification process of malathion, bifenthrin, and imidacloprid by B. odoriphaga carboxylesterase (Boest1).RESULTS: An alpha class CarE gene Boest1 was cloned from B. odoriphaga. The results of real-time quantitative polymerase chain reaction showed that Boest1 is up-regulated with age during the larval stage, and the level of transcription of Boest1 is higher in the midgut and Malpighian tubule than in other tissues. The expression level of Boest1 was significantly increased after exposure to malathion and bifenthrin. Recombinant BoEST1 expressed in vitro showed high catalytic activity toward ⊍-naphthyl acetate, which was substantially inhibited by malathion and triphenyl phosphate. The in vitro metabolism assays showed that BoEST1 demonstrates hydrolytic capacity toward malathion and bifenthrin but not imidacloprid. The binding free energy analysis indicates that BoEST1 has a higher affinity for malathion and bifenthrin than imidacloprid.CONCLUSION: These results suggest that BoEST1 plays a role in the breakdown of insecticides and may be involved in the development of resistance in the Chinese chive pest B. odoriphaga; our findings also provide data for better pest management and perspectives for new pesticides development.

Inducible Gut-Specific Carboxylesterase SlCOE030 in Polyphagous Pests of Spodoptera litura Conferring Tolerance between Nicotine and Cyantraniliprole

“…These results agreed with a previous study in which Boest1, an α esterase of B. odoriphaga, was most highly expressed in the midgut, suggesting that the midgut plays a key role in metabolizing toxic xenobiotics. 22 Similarly, SlCOE030 was also found to be induced by ricin, imidacloprid, xanthotoxin, and fluralaner. 23,48 We believed that SlCOE030 is a particular detoxification gene of α-esterase, which may be induced simultaneously by plant compounds or synthetic insecticides due to the coevolution between S. litura and tobacco.…”

“…For example, the decomposition rates of malathion and bifenthrin after incubation with the recombinant Boest1 protein of B. odoriphaga were 27.14 and 31.42%, respectively. 22 The CarE6 protein of T. cinnabarinus decomposed 41.7% of fenpropathrin, indicating that the CarE6 protein effectively metabolized fenpropathrin. 20 In the present study, the specific activities of the in vitro expressed SlCOE030 protein toward α-NA and β-NA were determined, and the results indicated that the recombinant protein was sufficient to test the capacity of the SlCOE030 protein to metabolize cyantraniliprole (Table 2).…”

“…12,44−47 CarEs, as important detoxification metabolism enzymes, were shown to be associated with detoxification of secondary plant metabolites and synthetic insecticides in insects. 22,23,32,48,49 To explore the potential roles of an α class CarE from S. litura in detoxifying cyantraniliprole and nicotine, SlCOE030 was identified from our transcriptome (Table S2). SlCOE030 was distributed on chromosome 12 and contained two introns and three exons (Figure 1A).…”

“…To detoxify toxic compounds from plants or synthetic insecticides, insects have evolved defense mechanisms, which particularly involve detoxification enzymes such as P450s, GSTs, UGTs, CarEs, and ABCs. ,− CarEs, as important detoxification metabolism enzymes, were shown to be associated with detoxification of secondary plant metabolites and synthetic insecticides in insects. ,,,, To explore the potential roles of an α class CarE from S. litura in detoxifying cyantraniliprole and nicotine, SlCOE030 was identified from our transcriptome (Table S2).…”

“…For example, the decomposition rates of malathion and bifenthrin after incubation with the recombinant Boest1 protein of B. odoriphaga were 27.14 and 31.42%, respectively . The CarE6 protein of T.…”