Molecular Mechanism Of Resistance To Beta-cypermethrin In Aphid Constrictor

Rhopalosiphum padi is one of the most important pests that harm wheat production safety.At present,beta-cypermethrin is widely used in crop pest control in China.However,its large-scale use has led to the resistance and adaptability of Rhopalosiphum padi to it in the field.Based on the early field resistance monitoring and laboratory selection of aphids to obtain high resistance strains,this study investigated the molecular mechanism of Rhopalosiphum padi’s resistance to beta-cypermethrin at the transcriptome level.The main contents are as follows:The resistance to beta-cypermethrin was monitored and a strain resistant to beta-cypermethrin LC₅₀（2984.84 mg/L）was established.Based on transcriptome techniques,the transcriptional expression characteristics of beta-cypermethrin induced by resistant and sensitive strains were elucidated,and the differentially expressed genes were screened.Among them,there were 1973 differentially expressed genes in the induction group and 2371 differentially expressed genes in the control group.The obtained differentially expressed genes were sorted out and a library was constructed.The GO enrichment analysis of these genes indicated that there were certain functional differences between resistant and sensitive strains,which may be involved in the formation of Rhopalosiphum padi resistance.The GAPDH gene was identified as the reference gene stably expressed in the insecticide treated condition,and the detection parameters of quantitative PCR technology were optimized.Through the bioinformatics analysis of the differentially expressed gene library,the potential resistance genes of Rhopalosiphum padi constrictus to beta-cypermethrin were screened,including 1 voltage-gated sodium channel gene,23potassium ion channel genes,26 cytochrome P450 genes,6 esterase genes,2glutathione S-transferase genes,3 ATP-binding cassette transporter genes,25UDP-glycosyltransferase,26 cuticular protein genes.The m RNA expression abundance of g1222,CYP380C47 and UGT344C6 was detected at the transcriptional level,and the results showed that the expression levels of the three genes of resistance strains were all higher than those of the sensitive strains,which were 18.66-fold,26.48-fold and20.67-fold differentially expressed,respectively,which was consistent with the results of transcriptome sequencing.Through transcriptional expression,it was preliminarily clear that the high expression of these three genes in Rhopalosiphum padi was closely related to the development of beta-cypermethrin resistance mechanism.Combined with the results of previous experiments and bioinformatics analysis,it can be inferred that the high level of resistance to beta-cypermethrin was probably the result of the joint action of multiple pathways.