Adaptive glutathione S-transferase genes induced by DIMBOA as potential RNAi targets against Ostrinia furnacalis

The arms race between insect-resistant secondary metabolites in plants and the detoxification genes of their natural enemies reveals the intricate co-evolutionary dynamics between the Asian corn borer (Ostrinia furnacalis) and its host plant, maize, and provides a new perspective for the potential control of pests. In this study, ELISA and transcriptome revealed that the glutathione S-transferases were involved in the detoxification of O. furnacalis to maize secondary metabolite 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA). The OfGST family was identified through comparative genomic methods, revealing expression patterns of 15 OfGSTs potentially related to DIMBOA metabolism. RT-qPCR showed significant induction of OfGSTd2, OfGSTd3, OfGSTm2, and OfGSTs1 in the midgut tissues of second-instar larvae after DIMBOA treatment. OfREase-target double interference targeting these OfGSTs resulted in increased larval mortality at sublethal concentrations, and docking results indicated distinct mechanisms of action for the four OfGSTs on DIMBOA. Our results indicate that OfGSTd2, OfGSTd3, OfGSTm2, and OfGSTs1 play different and crucial roles in the adaptation of O. furnacalis to DIMBOA, highlighting their potential as latent targets for prevention and control strategies. Our study provides an in-depth exploration of the GST gene family in the O. furnacalis, elucidates the potential roles of OfGSTs in adaptation to DIMBOA and explored their potential ability as a target for prevention and control.