CYP6CX2 and CYP6CX3 mediate thiamethoxam resistance in field whitefly, Bemisia tabaci (Hemiptera:Aleyrodidae)

Abstract

Cytochrome P450 monooxygenases (P450s) are well-known for their crucial roles in the detoxification of xenobiotics. However, whether CYP6CX2 and CYP6CX3, 2 genes from our Bemisia tabaci (B. tabaci) MED/Q genome data were associated with detoxification metabolism and confer resistance to thiamethoxam is unclear. In this study, we investigated the role of CYP6CX2 and CYP6CX3 in mediating whitefly thiamethoxam resistance. Our results showed that mRNA levels of CYP6CX2 and CYP6CX3 were up-regulated after exposure to thiamethoxam. Transcriptional levels of 2 genes were overexpressed in laboratory and field thiamethoxam resistant strains by RT-qPCR. These results indicate that the enhanced expression of CYP6CX2 and CYP6CX3 appears to confer thiamethoxam resistance in B. tabaci. Moreover, linear regression analysis showed that the expression levels of CYP6CX2 and CYP6CX3 were positively correlated with thiamethoxam resistance levels among populations. The susceptibility of whitefly adults was markedly increased after silencing 2 genes by RNA interference (RNAi) which further confirming their major role in thiamethoxam resistance. Our findings provide information to better understand the roles of P450s in resistance to neonicotinoids and suggest that these genes may be applied to develop target genes for sustainable management tactic of agricultural pests such as B. tabaci.

Cytochrome P450 CYP6EM1 Underpins Dinotefuran Resistance in the Whitefly Bemisia tabaci

“…tabaci, M. persicae, exhibits high detoxification capacity for imidacloprid and thiamethoxam, ,, and likewise, CYP6AY1 from N. lugens can metabolize imidacloprid. , In the current research, the level of CYP6EM1 gene expression was remarkably higher for the indoor-resistant strain than for the indoor susceptible strain.…”

“…For instance, the well-known resistance gene CYP6CM1 in B. tabaci is significantly overexpressed, enabling the metabolism of imidacloprid, thiacloprid, thiamethoxam, and pyriproxyfen. 20,40 CYP6CX3 from B. tabaci, M. persicae, exhibits high detoxification capacity for imidacloprid and thiamethoxam, 21,41,42 and likewise, CYP6AY1 from N. lugens can metabolize imidacloprid. 42,43 In the current research, the level of CYP6EM1 gene expression was remarkably higher for the indoor-resistant strain than for the indoor susceptible strain.…”

Comparative Transcriptomics Analysis Reveals Rusty Grain Beetle’s Aggregation Pheromone Biosynthesis Mechanism in Response to Starvation

“…Cytochrome P450s is a group of widespread metabolic enzymes involved in the oxidation of various of endogenous compounds, such as steroids and hormones, as well as exogenous compounds, including alcohol, drugs, and environmental pollutants [40]. In this study, starvation up-regulated a large number of cytochrome-P450s-related genes, suggesting that they may play a key role in the fight against starvation.…”