title: Involvement of Three Esterase Genes from Panonychus citri (McGregor) in Fenpropathrin Resistance.
abstract: The citrus red mite, Panonychus citri (McGregor), is a major citrus pest with a worldwide distribution and an extensive record of pesticide resistance. However, the underlying molecular mechanism associated with fenpropathrin resistance in this species have not yet been reported. In this study, synergist triphenyl phosphate (TPP) dramatically increased the toxicity of fenpropathrin, suggesting involvement of carboxylesterases (CarEs) in the metabolic detoxification of this insecticide. The subsequent spatiotemporal expression pattern analysis of PcE1, PcE7 and PcE9 showed that three CarEs genes were all over-expressed after insecticide exposure and higher transcripts levels were observed in different field resistant strains of P. citri. Heterologous expression combined with 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetra-zolium bromide (MTT) cytotoxicity assay in Spodoptera frugiperda (Sf9) cells revealed that PcE1-, PcE7- or PcE9-expressing cells showed significantly higher cytoprotective capability than parental Sf9 cells against fenpropathrin, demonstrating that PcEs probably detoxify fenpropathrin. Moreover, gene silencing through the method of leaf-mediated dsRNA feeding followed by insecticide bioassay increased the mortalities of fenpropathrin-treated mites by 31% (PcE1), 27% (PcE7) and 22% (PcE9), respectively, after individual PcE gene dsRNA treatment. In conclusion, this study provides evidence that PcE1, PcE7 and PcE9 are functional genes mediated in fenpropathrin resistance in P. citri and enrich molecular understanding of CarEs during the resistance development of the mite.
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. sxmshenxiaomin@163.com.
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Shen
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. leochongyu@163.com.
authors.forename: Chong-Yu
authors.initials: CY
authors.lastname: Liao
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. luxueping91@163.com.
authors.forename: Xue-Ping
authors.initials: XP
authors.lastname: Lu
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. zhewangswu@163.com.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. wangjinjun@swu.edu.cn.
authors.forename: Jin-Jun
authors.initials: JJ
authors.lastname: Wang
authors.affiliation: Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Chongqing 400716, China. douwei80@swu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Dou
mesh_terms: D000818:Animals; D002265:Carboxylic Ester Hydrolases / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics; D004950:Esterases / Q000235:genetics* / Q000378:metabolism; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism; D007306:Insecticides / Q000494:pharmacology; D008925:Mites / Q000187:drug effects / Q000201:enzymology*; D011722:Pyrethrins / Q000494:pharmacology*; D018411:Spodoptera
chemical_list: D019476:Insect Proteins; D007306:Insecticides; D011722:Pyrethrins; C044267:fenpropathrin; D004950:Esterases; D002265:Carboxylic Ester Hydrolases
keywords: Panonychus citri; RNA interference; carboxylesterase; fenpropathrin resistance; heterologous expression