Genome-Wide Identification and Expression Analysis of the Cytochrome P450 Gene Family in Bemisia tabaci MED and Their Roles in the Insecticide Resistance

Abstract

The whitefly, Bemisia tabaci MED (Hemiptera: Aleyrodidae), is an omnivorous agricultural pest, which causes huge economic losses to agriculture and is highly resistant to many pesticides. The overexpression of cytochrome P450 may play an important role in host adaptation and insecticide resistance in B. tabaci MED. Therefore, the present study systematically analyzed the cytochrome P450 gene family at the genome-wide level to understand its function in B. tabaci MED. Our analysis identified 58 cytochrome P450 genes in B. tabaci MED, among which 24 were novel. Phylogenetic analysis revealed broad functional and species-specific diversification in B. tabaci MED P450, suggesting the role of multiple P450 genes in detoxifying. Reverse transcription-real time quantitative PCR (RT-qPCR) showed that CYP4CS2, CYP4CS5, CYP4CS6, CYP4CS8, CYP6DW4, CYP6DW5, CYP6DW6, CYP6DZ8, and CYP6EN1 genes increased significantly after two days of exposure to imidacloprid. Interestingly, all nine genes belonged to the CYP4 and CYP6 families. A decrease in the expression of five genes (CYP6DW4, CYP6DW5, CYP6DW6, CYP6DZ8, and CYP4CS6) via RNA interference (RNAi) resulted in a significant increase in the mortalities of whiteflies when exposed to imidacloprid. These results indicate that the overexpression of the P450 genes may play an essential role in imidacloprid tolerance of B. tabaci MED. Thus, the present study provides basic information on P450 genes in B. tabaci MED, which will further help elucidate the insecticide resistance mechanism in the agricultural pest whitefly.

Transcriptome-Wide Identification of Cytochrome P450s in Tea Black Tussock Moth (Dasychira baibarana) and Candidate Genes Involved in Type-II Sex Pheromone Biosynthesis

“…Of all the DbP450s, CYPs in the families of CYP4 and CYP6 accounted for more than half the identified P450s in D. baibarana. Cytochrome P450s from the CYP4 and CYP6 families have been reported to be associated with pesticide resistance and host adaptation [19]. Therefore, it is speculated that the apparent CYP expansion in these two families may facilitate the survival of the tea black tussock moth in the tea plantations.…”

Genome-Wide Comparative Analysis of the Cytochrome P450 Monooxygenase Family in 19 Aphid Species and Their Expression Analysis in 4 Cereal Crop Aphids

“…In addition to detoxifying exogenous toxic compounds like insecticides and plant secondary insecticides, cytochrome P450s play a role in the synthesis and degradation of endogenous compounds in insects, including hormones and sex pheromones. They also mediate insect growth and development, host plant adaptation, and insecticide resistance [ 37 ]. To date, the CYP450 gene family has been identified and characterized in prokaryote (cyanobacteria) [ 38 ] and fungi [ 39 ].…”

“…And the CYP450 gene family has also been analyzed in various plants species, such as rice [ 40 ], tomato [ 41 ], wheat [ 42 ], maize [ 42 ], sorghum [ 43 ], soybean [ 44 ], tea [ 45 ], and others. In insects, it was reported that the CYP450 gene family of Drosophila melanogaster [ 46 ], silkworm ( Bombyx mori ) [ 47 ], Plutella xylostella [ 48 ], Scopula subpunctaria [ 49 ], cotton leafhopper ( Amrasca biguttula ) [ 50 ], bees [ 51 ], and Bemisia tabaci [ 37 ] have been identified and analyzed. However, several aphid species had not been reported yet.…”

Effect of High Temperature on Abamectin and Thiamethoxam Tolerance in Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae)

“…There is strong evidence that insecticide resistance is often conferred by cytochrome p450 monooxygenases [ 32 ]. For instance, CYP4 and CYP6 families are associated with imidacloprid tolerance in B. tabaci MED [ 33 ], while the CYP6DB3 gene was also over-expressed in thiamethoxam-resistant B. tabaci populations and the expression of CYP6DB3 can be induced under thiamethoxam selection pressure [ 34 ]. Furthermore, the P450 monooxygenase was found to be conducive to the development of abamectin resistance [ 35 ].…”