Studies on glutathione S-transferase gene involved in chlorfluazuron resistance of the diamondback moth, Plutella xylostella L. (Lepidoptera: Yponomeutidae)

Relationship between GST-3 and chlorfluazuron resistance was studied using the non-selected (NS) and chlorfluazuron-resistant (CFR) strains of the diamondback moth (DBM), Plutella xylostella L. The CFR strain exhibited higher GST-3 gene expression and GST activity compared to the NS strain. These results suggest that GST-3 is involved in detoxification of chlorfluazuron in DBM. Southern blot and nucleotide sequencing analyses showed that the higher GST-3 expression in the CFR strain may result from enhanced gene transcription rather than gene amplification or point mutations in the structural gene. Possible mechanisms of the higher GST-3 gene transcription in the CFR strain were discussed.