Inducible Gut-Specific Carboxylesterase in Polyphagous Pests of Conferring Tolerance between Nicotine and Cyantraniliprole.

Insecticides tolerance in herbivorous arthropods is associated with preadaptation to host plant allelochemicals. However, how plant secondary metabolites activate detoxifying metabolic genes to develop tolerance remains unclear. Herein, the tolerance of larvae to cyantraniliprole was increased after nicotine exposure. An α esterase, , was predominantly expressed in the midgut and induced after exposure to cyantraniliprole, nicotine, and cyantraniliprole plus nicotine. with ectopically overexpressed enhanced cyantraniliprole and nicotine tolerance by 4.91- and 2.12-fold, respectively. Compared to UAS- and Esg-GAL4 lines, the Esg > line laid more eggs after nicotine exposure. knockdown decreased the sensitivity of nicotine-treated larvae to cyantraniliprole. Metabolism assays indicated that recombinant SlCOE030 protein metabolizes cyantraniliprole. Homology modeling and molecular docking analysis demonstrated that SlCOE030 exhibits effective affinities for cyantraniliprole and nicotine. Thus, insect CarEs may result in the development of cross-tolerance between synthetic insecticides and plant secondary metabolites.