The expression of Spodoptera exigua P450 and UGT genes: tissue specificity and response to insecticides

Abstract

Cytochrome P450 and UDP-glucosyltransferase (UGT) as phase I and phase II metabolism enzymes, respectively, play vital roles in the breakdown of endobiotics and xenobiotics. Insects can increase the expression of detoxification enzymes to cope with the stress from xenobiotics including insecticides. However, the molecular mechanisms for insecticide detoxification in Spodoptera exigua remain elusive, and the genes conferring insecticide metabolisms in this species are less well reported. In this study, 68 P450 and 32 UGT genes were identified. Phylogenetic analysis showed gene expansions in CYP3 and CYP4 clans of P450 genes and UGT33 family of this pest. P450 and UGT genes exhibited specific tissue expression patterns. Insecticide treatments in fat body cells of S. exigua revealed that the expression levels of P450 and UGT genes were significantly influenced by challenges of abamectin, lambda-cyhalothrin, chlorantraniliprole, metaflumizone and indoxacarb. Multiple genes for detoxification were affected in expression levels after insecticide exposures. The results demonstrated that lambda-cyhalothrin, chlorantraniliprole, metaflumizone and indoxacarb induced similar responses in the expression of P450 and UGT genes in fat body cells; eight P450 genes and four UGT genes were co-up-regulated significantly, and no or only a few CYP/UGT genes were down-regulated significantly by these four insecticides. However, abamectin triggered a distinct response for P450 and UGT gene expression; more P450 and UGT genes were down-regulated by abamectin than by the other four compounds. In conclusion, P450 and UGT genes from S. exigua were identified, and different responses to abamectin suggest a different mechanism for insecticide detoxification.

Adaptation by copy number variation increases insecticide resistance in fall armyworms

“…The presence of a single haplotype of CNVs in PR and of two haplotypes of CNVs in the MS imply the existence of positive selection that is specific to PR because positive selection fixes only a single haplotype in a population. The overexpression of CYP9A genes upon the treatment of insecticides was observed from the fall armyworm 31 , Beet armyworm (S.exigua) 32 , and Tobacco cutworm (S.litura) 33 , and smaller tea tortrix (Adoxophyes honmai) 34 , supporting the association between CYP9A and insecticide resistance. The presence of ADH gene cluster was also found in a previous study 30 .…”

Molecular characterization, expression pattern and metabolic activity of flavin‐dependent monooxygenases inSpodoptera exigua

“…The changes in expression levels during the development process were in line with the changes in FMO enzymatic activities in S. exigua , and the tissue expressions of SeFMO mRNAs also reflected the distribution characteristics of FMO enzymatic activities in larval tissues (Tian et al ., ). The pattern of tissue expression was similar to that of insect P450s responsible for insecticide detoxification (Feyereisen, ; Hu et al ., ). The expression characteristics of SeFMO s in larval tissues and developmental stages suggest that they have roles in xenobiotic metabolism.…”

Identification and expression analysis of cytochrome P450 genes in Plecoptera oculata (Lepidoptera: Noctuidae)

“…Cytochrome P450 monooxygenases (CYPs) are an ancient gene superfamily with a 3.5 billion year history and vast species diversity (Nelson 1998). In addition, CYPs comprise one of the three main groups of detoxification enzymes used by insects that contain the heme-thiolate protein and play crucial roles in the detoxification of most pesticides (Hodgson 1985), including chlorantraniliprole (Hu et al 2017;Wang et al 2018), abamectin (Gao et al 2016;Hu et al 2017), DDT (Chiu et al 2008;Simma et al 2019), lambdacyhalothrin (Hu et al 2017), metaflumizone (Hu et al 2017), phoxim (Hu et al 2016;Li et al 2015), chlorpyrifos (Tang et al 2017;Wang et al 2017), thiamethoxam (Chen et al 2017;Sun et al 2018), dinotefuran (Sun et al 2018), imidacloprid (Chen et al 2017;Chen et al 2019;Sanada-Morimura et al 2019), indoxacarb (Cui et al 2018), and a variety of pyrethroids (Chen et al 2017;Simma et al 2019;Xu et al 2016;Zhu et al 2010). Moreover, CYPs are also involved in the processing of plant secondary metabolites (Giraudo et al 2015) and are crucial components in a range of physiological processes, including the epoxidation of methyl farnesoate to juvenile hormone III (Helvig et al 2004), ecdysteroid catabolism (Guittard et al 2011), epoxidation of a (Z)-double bond in a pheromone precursor (Rong et al 2014), insect olfactory function (Keeling et al 2013), and metabolism of methanol (Wang et al 2012).…”