Research On The Response And Function Of Tomato MiR319c Against Botrytis Cinerea Infection

MiR319 is a conserved mi RNA family,it has been found that miR319 is involved in plant growth,responding to drought,cold and salt stress,but there is almost no research on fungal stress response.This study uses biological experiments to study the biological function of plant miR319 c and its target genes during Botrytis cinerea infection.The main results obtained were summarized as follows:(1)RT-qPCR showed that miR319 c was down-regulated in B.cinerea infected tomato,but its target genes TCP24 and TCP29 were up-regulated,suggesting that mi R319 c may be involved in the response of tomato leaves to B.cinerea infection through regulating of its target genes.(2)In transgenic Arabidopsis and transgenic tomato,miR319 c was over-expressed.Accordingly,the expression of target genes was significantly decreased.(3)The results of microbiology confirmed that there were no obvious lesions in transgenic Arabidopsis leaves and transgenic tomato leaves.The result of trypan blue staining showed that compared to their own wild type,B.cinerea in transgenic plants were obviously inhibited,indicating that overexpression of miR319 c enhances the resistance of transgenic plants to B.cinerea.(4)Based on the B.cinerea resistance of transgenic plants,this study investigated the expression of jasmonate synthesis and signal transduction genes,miRNA metabolic processes related genes and some response-related miRNAs through RT-qPCR.Among them,JA synthesis and signal transduction-related gene expression was mostly up-regulated.JA may induced B.cinerea to activate downstream defense-related responses.In addition,the experimental results showed that the expression of plants response to stress-related miRNAs were affected by the overexpression of miR319 c.However,over-expression of mi R319 c or infection by B.cinerea does not have a significant effect on the expression of key genes in miRNA synthetic pathways.(5)Based on the RNAi and overexpression technology,we constructed vectors of TCP RNAi and overexpression TCP,introduced them into Arabidopsis thaliana.In conclusion,transgenic Arabidopsis and tomato plants overexpressing ath-miR319 c were successfully obtained,revealing that overexpression of miR319 c enhances the resistance of transgenic plants to B.cinerea.