Transcriptome Analysis of (Homoptera: Delphacidae) in Response to Sulfoxaflor and Functional Verification of Resistance-Related P450 Genes.

The white-back planthopper (WBPH), , is a major rice pest in China and in some other rice-growing countries of Asia. The extensive use of pesticides has resulted in severe resistance of to variety of chemical insecticides. Sulfoxaflor is a new diamide insecticide that acts on nicotinic acetylcholine receptors (nAChRs) in insects. The aim of this study was to explore the key genes related to the development of resistance to sulfoxaflor in and to verify their functions. Transcriptomes were compared between white-back planthoppers from a susceptible laboratory strain (Sus-Lab) and Sus-Lab screened with the sublethal LC dose of sulfoxaflor for six generations (SF-Sel). Two P450 genes ( and ) and three transcription factors (, and ) with upregulated expression verified by qRT-PCR were detected in the Sus-Lab and SF-Sel strains. The functions of and were analyzed by RNA interference, and the relative normalized expressions of and in the SF-Sel population were lower than under dsGFP treatment after dsRNA injection. Moreover, the mortality rates of SF-Sel population treated with the LC concentration of sulfoxaflor after the injecting of dsRNA targeting and were significantly higher than in the dsGFP group from 72 h to 96 h ( < 0.05), and mortality in the knockdown group was clearly higher than that of the knockdown group. The interaction between the tertiary structures of and and sulfoxaflor was also predicted, and showed a stronger metabolic ability to process sulfoxaflor. Therefore, overexpression of and may be one of the primary factors in the development of sulfoxaflor resistance in .