title: Expression induction of P450 genes by imidacloprid in Nilaparvata lugens: A genome-scale analysis.
abstract: The overexpression of P450 monooxygenase genes is a main mechanism for the resistance to imidacloprid, a representative neonicotinoid insecticide, in Nilaparvata lugens (brown planthopper, BPH). However, only two P450 genes (CYP6AY1 and CYP6ER1), among fifty-four P450 genes identified from BPH genome database, have been reported to play important roles in imidacloprid resistance until now. In this study, after the confirmation of important roles of P450s in imidacloprid resistance by the synergism analysis, the expression induction by imidacloprid was determined for all P450 genes. In the susceptible (Sus) strain, eight P450 genes in Clade4, eight in Clade3 and two in Clade2 were up-regulated by imidacloprid, among which three genes (CYP6CS1, CYP6CW1 and CYP6ER1, all in Clade3) were increased to above 4.0-fold and eight genes to above 2.0-fold. In contrast, no P450 genes were induced in Mito clade. Eight genes induced to above 2.0-fold were selected to determine their expression and induced levels in Huzhou population, in which piperonyl butoxide showed the biggest effects on imidacloprid toxicity among eight field populations. The expression levels of seven P450 genes were higher in Huzhou population than that in Sus strain, with the biggest differences for CYP6CS1 (9.8-fold), CYP6ER1 (7.7-fold) and CYP6AY1 (5.1-fold). The induction levels for all tested genes were bigger in Sus strain than that in Huzhou population except CYP425B1. Screening the induction of P450 genes by imidacloprid in the genome-scale will provide an overall view on the possible metabolic factors in the resistance to neonicotinoid insecticides. The further work, such as the functional study of recombinant proteins, will be performed to validate the roles of these P450s in imidacloprid resistance.
authors: Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China.
authors: Jianhua
authors: J
authors: Zhang
authors: Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China.
authors: Yixi
authors: Y
authors: Zhang
authors: Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China.
authors: Yunchao
authors: Y
authors: Wang
authors: Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China.
authors: Yuanxue
authors: Y
authors: Yang
authors: Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China.
authors: Xinzhu
authors: X
authors: Cang
authors: Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant Protection, Nanjing Agricultural University, Weigang 1, Nanjing 210095, China. Electronic address: liuzewen@njau.edu.cn.
authors: Zewen
authors: Z
authors: Liu
mesh_terms: D000818:Animals; D001681:Biological Assay; D003577:Cytochrome P-450 Enzyme System / Q000096:biosynthesis*; D004790:Enzyme Induction / Q000187:drug effects; D017344:Genes, Insect; D049750:Genome, Insect; D006430:Hemiptera / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology*; D007305:Insecticide Resistance / Q000235:genetics; D007306:Insecticides / Q000494:pharmacology*; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000494:pharmacology*
chemical_list: D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; C082359:imidacloprid; D003577:Cytochrome P-450 Enzyme System
keywords: Expression induction; Imidacloprid; Insecticide resistance; Nilaparvata lugens; P450 genes