Genetic mutations associated with chemical resistance in the cytochrome P450 genes of invasive and native Bemisia tabaci (Hemiptera: Aleyrodidae) populations in China

Abstract

Bemisia tabaci (Gennadius) is a species complex, and its two most damaging biotypes B and Q are globally distributed pests. Despite increasing biological and economic impacts, little is known about the evolutionary mechanisms that favor their competition with native populations. Here, we investigated the genetic mutations in the P450 gene of the invasive B, Q biotypes and the native Cv population. Four mutations associated with chemical resistance, Pro-Leu, Ala-Ser, Ser-Phe and Trp-Leu, were found in the cytochrome P450 CYP6C and CYP9F genes of the B and Q biotypes. Bioassay results also revealed that both the B and Q biotypes have about 12-47 times more resistance to acephate, betacypermethrin, methomyl, and 5-7 times more resistance to imidacloprid insecticide than Cv population. Our results provide a molecular approach for better understanding and monitoring the pesticide resistances of invasive and native B. tabaci populations in China.

Biochemical Markers for Acetamiprid and Imidacloprid Neonicotinoid Insecticides Selectivity in the Cotton White Fly, Bemisia tabaci, the Cotton Leafworm, Spodoptera littoralis and Honey Bee, Apis mellifera

“…The P450 genes (also called CYP) are found in the genomes of virtually all organisms. In a harmony with the results of the present study, the development of high metabolic resistance to neonicotinoids -including acetamiprid and imidacloprid -has been reported in pests such as B. tabaci is conferred by enhanced oxidative detoxification by overexpression of the cytochrome P 450 monooxygenase CYP6CM1 (Karunker et al, 2008 andNauen et al, 2013); CYP6C and CYP9F (Qiu et al, 2009). The recent association of CYP6CM1 with imidacloprid resistant B. tabaci nymphs and adults, where nymphs are 4-10 times less sensitive to imidacloprid than their adult counterparts, makes this enzyme the most likely candidate underlying this agespecific resistance (Karunker et al, 2008;Karunker et al, 2009).…”

Transcriptomic and Proteomic Responses of Sweetpotato Whitefly, Bemisia tabaci, to Thiamethoxam

“…CYP6cm1 , which was over expressed in several laboratory-selected B. tabaci strains, was considered as a legitimate molecular marker for screening imidacloprid resistance in the field [24]. The expression levels of CYP6C and CYP9F , respectively, were elevated 5–7 fold in imidacloprid resistant B. tabaci [50]. After more than 30 generations of selection, thiamethoxam resistance reached 66-fold in resistant B. tabaci [25], [26].…”

Gene expression of detoxification enzymes in insecticide-resistant and insecticide-susceptible Bemisia tabaci strains after diafenthiuron exposure

“…The P450 genes metabolize endogenous compounds and of all the P450 families, the CYP6 family has been most often implicated in insecticide resistance (Pavek & Dvorak 2008;Scott 2008;Puinean et al 2010). For example, CYP6CM1 and CYP9F have been reported to be linked with imidacloprid resistance in whitefly (Karunker et al 2008;Qiu et al 2009;Jones et al 2011), and CYP6CX1 reportedly exhibited significantly higher mRNA levels in the context of imidacloprid and thiamethoxam resistance in whitefly (Zhuang et al 2011;Yang et al 2013). This finding may indicate that CYP6CM1, CYP6CX1 and CYP9F are involved not only in imidacloprid and thiamethoxam resistance but also in diafenthiuron resistance in whitefly.…”