Molecular Characterization Of CYP6 Family Genes Of Grapholita Molesta(Busck)and And Its Response To Pesticides

Grapholita molesta?busck?has a long history of harm,and it is a worldwide fruit-borne pest.The most effective way to control G.molesta is chemical control.Many insects are resistant to chemical pesticides due to the large number of repeated use of chemical pesticides.Cytochrome P450 is an important metabolic enzyme system for insecticides and secondary metabolites in plants.The enhancement of detoxification and metabolism is the main cause of insect resistance.Many experiments have now proved that insect cytochrome P450 CYP6 family functions and insects.which related to metabolic pesticides.In this paper,the molecular characteristics of the cytochrome P450 CYP6 family gene of G.molesta were analyzed by bioinformatics methods,and its possible functions were speculated.The induction characteristics of different pesticides on CYP6 family genes were revealed at the molecular level.The main results are as follows:1.Eight cytochrome P450 genes were analyzed by bioinformatics methods,named CYP6B74,CYP6AB112,CYP6AB113,CYP6AB114,CYP6AB115,CYP6AB116,CYP6AB117,CYP6AN35.1566bp¹957bp,encoding 498⁵30 amino acids,all hydrophilic.The m?Lti-sequence alignment showed that the cytochrome P450 of G.molesta?Busck?was basically consistent with the conserved domain of insect cytochrome P450.The phylogeny showed that G.molesta cytochrome P450 had high similarity within and between species.2.Three types of insecticides,including malathion,chlorantraniliprole and deltamethrin,were evaluated with regards to their effects on the eggs and ad?Lts of G.molesta.Bioassays were performed on the eggs and ad?Lts of oriental fruit moth using dipping and film methods.Compared with the with malathion and chlorantraniliprole,the treatment by deltamethrin significantly reduced the hatching rate of the eggs.The lethal median concentration(LC₅₀)with deltamethrin was 16.81?g/m L,and the lethal median concentrations for malathion and chlorantraniliprole were 218.17?g/m L and 561.52?g/m L,respectively.Treatments with malathion showed the best lethal effect on ad?Lts of G.molesta.The lethal median concentration(LC₅₀)was 3.08?g/m L,and the median lethal concentrations with chlorantraniliprole and deltamethrin were 130.78?g/m L and 23.52?g/m L,respectively.Deltamethrin can be used to control the oriental fruit moth in egg stage,and malathion can be used to control the oriental fruit moth in ad?Lt stage.3.The expression of cytochrome P450 gene in different concentrations of malathion,deltamethrin and chlorantraniliprole was studied by q PCR.The results showed that cytochrome P450 was induced by malathion.After expression,the expression levels of CYP6B74,CYP6AB113,CYP6AB115 and CYP6AN35 genes were up-regulated,showing an induction trend;after malathion treatment,the down-regulation of CYP6AB114 gene expression was inhibited;CYP6AB116,CYP6AB117 in malathion Under induction,the gene expression reached the highest at the dose of malathion LC₃₀.Compared with the control,the expression level was increased by 1.2 times.CYP6AB116 and CYP6AB117 showed lowdose induction.The expression of CYP6AB112 gene was not detected before and after malathion induction.Significant changes may not be involved in the metabolism of malathion in G.molesta.The expression levels of CYP6AB112,CYP6AB114,CYP6AB115 and CYP6AB116 genes decreased rapidly after cytochrome P450 induced by deltamethrin.The deltamethrin inhibited CYP6AB112,CYP6AB114,CYP6AB115 and CYP6AB116 genes;CYP6B74 and CYP6AN35 in bromine At the dose of cypermethrin LC₃₀,the expression of the gene reached the highest,showing low dose induction.The expression of CYP6AB113 and CYP6AB117 m RNA was not significantly different before and after deltamethrin treatment.The expression of CYP6AB114,CYP6AB115,CYP6AB116,CYP6AB117 and CYP6B74 m RNA decreased after treatment with different concentrations of chlorantraniliprole,and chlorantraniliprole inhibited CYP6AB114,CYP6AB115,CYP6AB116,CYP6AB117 and CYP6B74 genes;CYP6AB112CYP6AB113 and CYP6AN35 showed the highest gene expression at the chlorantraniliprole LC10 dose,and CYP6AB112,CYP6AB113 and CYP6AN35 showed low dose induction.The cytochrome P450 CYP6 family genes related to resistance to malathion,deltamethrin and chlorantraniliprole were screened,which provided a theoretical basis for the further study of the mechanism of subsequent genes.