Study Of Target Mimicry Technique On The Role Of Resistance To CMV

Cucumber mosaic virus (CMV) is one of the most damaging phytopathogen, and also asmodel virus for researching plant-virus interaction. Owing to lacking of resistance gene, itexerts little effect on the virus prevention. The research of anti-CMV, as yet, mainly focus ontransgenic expression of virus proteins, part of virus gene sequence and CMV satellite RNA.Therefore, the primary mission in prevention and control of plant virus disease is to search themore effectively antiviral method and strategy. In this paper, we use Target Mimicry, which isreported recently, with CMV as the research object, to explore the feasibility of this technologyon plant anti-virus.The target mimicy could be identified and interacted with the miRNA target genes, butcould not be cleaved by miRNA. Integrating the designed mimics into the viral genome,combined with the interaction between the plant miRNA and the target mimics, we investigatethe interaction how to regulate the replication, translation, accumulation level and pathogeniceffects of CMV, in order to ensure the feasibility of the target mimicy using in the prevention ofCMV.First, target mimicries of miR159, miR162and miR170were carried on the CMV-GFPRNA3containing the GFP reporter gene and inoculated the N.benthamiana by agroinfiltration.Fluorescence intensity and Western Blot results showed that GFP fluorescence reporter geneexpression level in the experimental groups was significantly down-regulated compared to thecontrol group. With this clarification, endogenous miRNAs binding to its target mimicrysequences inhibit the accumulation of virus. Furthermore, we analysis the mechanism of targetmimicry inhibiting viral accumulation from CMV minus-strand synthesis and translational level.Target mimicries of miR162, miR164and miR170is carried on non-complete CMV-GFPRNA3, and fluorescence observation showed fluorescent intensity in the experimental groupswas significantly down-regulated compared to the control group, indicating that endogenousmiRNA binding to its target mimicry significantly inhibited the translation of proteins. Weextrac t the total RNA of samples and obtain GFP minus strand by reverse transcription PCR.Results show that endogenous miRNA binding to its target mimicry significantly inhibited thegeneration of CMV minus strand. Finally, target mimicries were inserted into the wild-typeCMV genomic RNA by Northern Blot accumulation of various viral genomes, and results showed that the target mimicry repressed the complete accumulation of the virus in differentlevels.In summary, we initially identified that Target Mimicry could inhibit the accumulation ofCMV in a certain extent via attenuation virus minus strand and protein. If this technology couldbe used in transgenic plants, this research could establish a new method for antiviral.