Genome-wide identification of ABC transporters and their contribution to triflumezopyrim susceptibility regulated by microRNAs in Laodelphax striatellus

The small brown planthopper (SBPH), Laodelphax striatellus, is a highly destructive pest, which seriously threatens the production of high-quality rice. Triflumezopyrim, a novel insecticide widely used against planthoppers, which will inevitably produce resistance in the process of long-term use. ATP-binding cassette (ABC) transporters play a significant role in phase III detoxification process and may contribute substantially to insecticide resistance. In this study, 41 ABC transporters were identified in the L. striatellus genome. Synergism studies revealed that verapamil significantly increased triflumezopyrim toxicity against L. striatellus. Five ABC transporters, ABCC12, ABCF3, ABCG11, ABCG12 and ABCH1, were up-regulated over two-fold following triflumezopyrim exposure. Furthermore, RNAi-mediated suppression of ABCG11 or ABCH1 expression significantly increased susceptibility to triflumezopyrim. Additionally, injection of agomir-PC-5p-3991_515 significantly decreased the expression of ABCG11 and ABCH1, and enhanced the susceptibility of L. striatellus to triflumezopyrim. Dual luciferase reporter assay confirmed the interaction between PC-5p-3991_515 and ABCG11 or ABCH1. These results demonstrate that PC-5p-3991_515 modulates triflumezopyrim tolerance in L. striatellus by targeting ABCG11 and ABCH1. This study enhances the understanding of transcriptional regulation of triflumezopyrim tolerance mediated by miRNA-ABC transporter and has guiding significance for the management of L. striatellus and other pests.