Enhancing Resistance In Transgenic Tomato By Silencing MiR482a Of Late Blight,Salt And Drought Tolerance

Micro RNAs(mi RNAs)are 22 nucleotides(nt)endogenous RNA.They are one sort of key post-transcriptional regulators,mi RNA regulate biological processes such as development,metabolic pathway,stress response and so on.Tomato(Solanum lycopersicum)is inevitably infected by pathogens during its growth,which could bring huge losses to the production of tomato.mi R482 is one class of conserved mi RNA,peculiarly highly expressed in tomato.Its target NBS-LRR genes encoding plant immune receptors were considered,but also proven to be involved in various biotic stresses.Strategies to silence plant mi RNA,the opposite side of to over-express,have also became a hot research field.The emergence of novel technologies like STTM and Anti-ami RNA have notified its maturity day by day.By using two mi RNA silencing techniques to inhibit the expression of mi R482 a in tomato,and functional analysis of silencing tomato mi R482 a in resistance on late blight,salt and drought tolerance.Firstly,target genes of mi R482 a in tomato were predicted via bioinformation methods and using real-time quantitative PCR technique to analysis the expression patterns of mi R482 a and its targets under P.infestans,SA,salt and drought trentment.The result assumed that mi R482 a may respond to all of these stresses.Then,two mi482 a silencing vectors constructed in the laboratory stage were used to convert the silencing vector into tomato by transient and stable expression.We successfully constructed a transient silencing system and obtained a stable silence of transgenic tomato plants.The silencing vector was able to inhibit the expression of mi R482 a in tomato and promote the expression of its target gene.Finally,the transgenic tomato plants with stable silencing were treated with pathogens,high salt and drought.The physiological and biochemical indexes of transgenic silencing plants were significantly changed compared with those of wild type plants,Enhancing resistance in transgenic tomato of late blight,salt and drought tolerance.this research was firstly systematically an exploration of mi R482 a role in stress-resistance upon a mi RNA-silenced facet,which provided a new layer to study the resistance of tomato to stress.