Detoxifying Enzymes and Gene Expression in Whitefly

Activities of three detoxifying enzymes (GST, EST, and P450) were measured as previously described (Wang et al., 2020a (link)) with slight alterations. The median lethal concentration (LC₅₀) treatment comprised adults that survived treatment with the LC₅₀ concentration for 96 h, and the control group was made of insects treated with the control for the same period of time. For each group, 200 mixed-sex B. tabaci individuals were sampled as one replicate. Three replicates were sampled for each of the three detoxifying enzymes. Protein content was measured using bovine serum albumin (BSA) as the standard with the method described by Bradford (1976) (link). Based on previous publications regarding P450-mediated pesticide resistance in B. tabaci (Wang Q. et al., 2020 (link); Zhou et al., 2020 (link)), expression levels of 12 detoxifying genes were measured via quantitative reverse transcription (qRT)-PCR as previously described (Wang et al., 2020a (link)): CYP6CX1v1, CYP6CX3, CYP6CX4, CYP6CX5, CYP6CM1, CYP6DW2, CYP6DW3, CYP6DZ4, CYP6DZ7, CYP303A1, CYP4C64, and CYP4G68. Expression data were normalized using TUB1α and EF-1α as the internal control genes, and the results were conducted in terms of the 2^−△△Ct method (Pfaffl, 2001 (link)). Primer sequences are shown in Supplementary Table S1.