The Roles Of MiR158 On Regulation Of Abiotic Stress Responses In Arabidopsis Thaliana

MicroRNA(miRNA)is a series of endogenous non-coding single-stranded RNA with a length of about 20?24 nucleotides,which plays an important role in regulating post-transcriptional expression of genes or inhibiting translation.miR158 is a conserved miRNA in Arabidopsis thaliana,but its function is unknown.Here,through reverse genetics and physiological and biochemical techniques,the expression patterns and functions of miR158 under abiotic stress were analyzed.The main results are as follows:1.Tissue expression profile analysis showed that the expression abundance of miR158 was low in cauline leaves and stem tissues of Arabidopsis,while high in roots,seeds and rosettes.2.The results of real time PCR indicated the expression of miR158 increased under cold stress,while decreased under salt and drought.3.The transgenic Arabidopsis thaliana with 35S:miR158a/b overexpressing miR158 were successfully constructed and the transgenic Arabidopsis thaliana with STTM158 that silenced miR158 were identified.The results revealed that the expression level of miR158 in 35S:miR158a/b transgenic plant was significantly higher than that of the wild type,while was significantly lower in STTM158 transgenic plants..4.The phenotypic performances of the two transgenic lines under salt stress and ABA stress were detected.It was found that the germination rate and cotyledon greening rate of 35S:miR158a/b plants decreased,and the root length became shorter,indicating a decrease in salt stress and ABA stress tolerance.However,the germination rate and cotyledon greening rate increased,and root length became longer in STTM158 transgenic plant,indicating an increase in salt stress and ABA stress tolerance.This indicated that the abundance of miR158 was negatively correlated the tolerance to salt stress in plants,and miR158 was involved in the ABA signaling pathway in plantsIn summary,this study found that the expression of miR158 was affected by cold damage,salt damage and drought stress.It was found that miR158 can participate in abiotic stress responses through the ABA signaling pathway,proving that miR158 can regulate Arabidopsis tolerance to salt stress.