Studies On MiRNAs Regulate The Expression Of CYP6CY3 Conferring Myzus Persicae(Sulzer) Host Plant Adaption

The peach potato or green peach aphid,Myzus persicae Sulzer(Hemiptera:Aphididae)is a important pest of a broad range of agricultural.causing significant damage by both direct feeding and the transmission of many plant viruses.New interventions are required to optimally and sustainably control the Myzus persicae.In this study,the two races of Myzus persicae was chosen as the research object Myzus peicae sensu stricto.Green,Myzus persicae sensu stricto.Red was sampled and reared on Chinese cabbage(Brassica rapa chinensis),Myzus persicae nicotianae.Green)was collected and reared on tobacco(Nicotiana tabacum L.).Through studies mechanism of Myzus persicae adaption from different host plants,CYP6CY3(Cytochrome P450)have been implicated in the oxidative detoxification of plant secondary metabolite nicotine.In order determination of the CYP6CY3 primitive copy number and relative expression in the two races of M.persicae.Filtered the CYP6CY3-target miRNAs through the high-throughput sequencing and verify which the candidate miRNAs,including miRNA-100 and let-7,are associated with the expression of CYP6CY3.The quantitative real time PCR test the CYP6CY3 primitive copy number and relative expression in the two races of M.persicae.results indicated that the DNA copy number of CYP6CY3 and mRNA expression of CYP6CY3 in M.persicae nicotianae(Green)is significantly higher than other races.A total of 66 conserved miRNAs and 17 novel miRNAs were identified in M.persicae nicotianae(Green)through the high-throughput sequencing.With bioinformatics software a total of 23 miRNAs were successfully predicted that possible directly target of CYP6CY3.The five miRNA were selected for RT-qPCR validation in the candidate miRNAs which concerned with CYP6CY3 expression(miR-100、miR-277、let-7、miR-3040、miR-3050).Based on miRNA functional deficiency/gain experimental in vivo,the result shows miR-100 and let-7 are negatively correlated with CYP6CY3 expression(p<0.05).The effects of functional deficiency/gain of miRNAs on CYP6CY3 expression and modulating the level of CYP6CY3 expression was effective the nicotine tolerance ability of aphids.Based on the cell-transfection and dual-luciferase reporter assay experiments in vitro,the miR-100 and let-7 was negative effects on the luciferase activity.Compared with the negative control,the miR-100 and let-7 could significantly down-regulate the Renilla luciferase activity of 74.43%and 92.65%respectively.The results show that CYP6CY3 is involved in Myzus persicae adaptation to different host plant,The miR-100 and let-7 are most directly involved in the post-transcriptional regulation of CYP6CY3 and inhibition the translation.Study on the resisitant mechanisms and regulation pathway can provide a new method for prevention and control of peach aphid.