Genome-editing study reveals conserved chitin synthase mutations confer benzoylurea resistance in fruit flies, indicating direct enzyme targeting across multiple pest control chemicals.
Key Points
To identify the direct molecular target and mode of action of benzoylurea insecticides and related chitin biosynthesis inhibitors in arthropods.
Identified an I1042M mutation in the chitin synthase 1 (CHS1) gene of benzoylurea-resistant Plutella xylostella, corresponding to an etoxazole-resistance mutation (I1017F) in spider mites.
Engineered homologous substitutions (I1056M and I1056F) into the Drosophila melanogaster CHS1 gene (kkv) using CRISPR/Cas9 and homology-directed repair.
Assessed insecticide susceptibility in homozygous mutant fly lines exposed to etoxazole, buprofezin, and multiple benzoylureas.
Homozygous fly lines bearing either I1056M or I1056F mutations exhibited strong resistance across all tested benzoylureas, etoxazole, and buprofezin.
Demonstrated that benzoylureas, etoxazole, and buprofezin share a conserved molecular mode of action via direct interaction with chitin synthase 1.