Cytpchrome P450 CYP4G68 Is Associated with Imidacloprid and Thiamethoxam Resistance in Field Whitefly, Bemisia tabaci (Hemiptera: Gennadius)

Abstract

The superfamily cytochrome P450s is involved in the evolution of insecticide resistance. However, whether CYP4G68, a differentially expressed gene identified from our transcriptomics analysis, confers resistance to the world’s heavily used insecticide class neonicotinoids is unknown. Hence, we explored the role of CYP4G68 in conferring imidacloprid and thiamethoxam resistance in Bemisia tabaci. The species B. tabaci MED developed low-to-high resistance to imidacloprid and thiamethoxam. Exposure to imidacloprid and thiamethoxam significantly increased the expression of CYP4G68. Moreover, quantitative real-time PCR analysis demonstrated that CYP4G68 was remarkably overexpressed in imidacloprid-resistant and thiamethoxam-resistant strains compared to susceptible strains. Further correlation analysis showed that CYP4G68 expression was significantly positively correlated with the associated resistance level in various strains of B. tabaci. These results suggest that the enhanced expression of CYP4G68 appears to mediate imidacloprid and thiamethoxam resistance in B. tabaci. Additionally, silencing CYP4G68 via RNA interference strongly increased the susceptibility of B. tabaci MED to imidacloprid and thiamethoxam. Collectively, this work revealed that CYP4G68 plays a vital role in imidacloprid and thiamethoxam resistance in B. tabaci MED. These findings will not only advance our understanding of the role of P450s in insecticide resistance but also provide a great potential target for the sustainable control of destructive insect pests such as whiteflies.

Knockdown of the Nicotinic Acetylcholine Receptor β1 Subunit Decreases the Susceptibility to Five Neonicotinoid Insecticides in Whitefly (Bemisia tabaci)

“…Research for understanding the mechanism of resistance formation helps for better control of these pests. In the research of resistance to neonicotinoids in pests, metabolic genes of insects in xenobiotic response to plant allelochemicals have been demonstrated to play an important role in the formation of resistance. − As the insecticidal targets of neonicotinoids, site mutations in insect nicotinic acetylcholine receptors were reported to change the susceptibility of insects to neonicotinoids. The R81T mutation in the β1 subunit has been reported in field imidacloprid-resistant peach aphids .…”

“…tabaci MEAM1. ,− Research of resistance formation mechanisms to neonicotinoids in B. tabaci MED has demonstrated that overexpression of detoxification enzymes is an important reason for enhanced metabolism ability of neonicotinoids, thus causing resistance. − However, the toxicological targets of neonicotinoids, nAChRs, have seldom been researched in whitefly, and related information on nAChRs in B. tabaci is lacking at present.…”

CYP6DW3 Metabolizes Imidacloprid to Imidacloprid-urea in Whitefly (Bemisia tabaci)

“…The IMI (700 g/kg WG, Bayer, Leverkusen, Germany) used in this study was dissolved in DMSO (Xilong Scientific, Guangdong, China) and diluted with ultrapure water depurated by a water purifier (Dequanxingye, Beijing, China). The bioassays were based on a special feeding system developed by Liang et al, and the feeding fluid containing different concentrations of pesticide was coadministered with 30% sucrose (Xilong Scientific, Guangdong, China) and 5% yeast extract (wt/vol) (Thermo Scientific, MA), and a total of six IMI concentrations were tested. For control groups, the subjects were fed with feeding fluid which contained no IMI.…”

“…Similarly, CYP402C1 shows a metabolism ability of IMI as well . Besides, CYP4G68 shows a significant link with resistance to IMI, and whitefly shows higher mortality when exposed in insecticide after RNAi of this gene . P450 genes such as CYP6DZ7 and CYP6C 64 are remarkably overexpressed in IMI-resistant whitefly population, which indicates that P450s affect whitefly resistance to IMI …”

Invasion genomics uncover complex introduction patterns of the globally invasive whitefly, Bemisia tabaciMED

“…The superfamily cytochrome P450s, among the most important phase I metabolic enzymes, participate in the metabolic detoxification of toxic xenobiotics and the reduction in the penetration rates of insecticides (Bass et al, 2015). There is mounting evidence to show that the cytochrome P450 monooxygenases gene family had been proved to be associated with insecticide resistance in B. tabaci MED (Liang et al, 2022; Yang et al, 2013). Moreover, B. tabaci MED has grown resistant to insecticides from many chemical classes, making it more tolerant to insecticides such as pyriproxyfen and neonicotinoids compared with the MEAM1 (Basit, 2019; Horowitz et al, 2005, 2020).…”