Beta Vulgaris Micrornas Bioinformatics Prediction And Salt-tolerant MiRNA Expression Analysis

With the increasing effect of soil salinization for the production and quality ofglobal foods, studies of molecular mechanism of salt tolerance in plants has becomethe research hot spot in ecological agricultural science. Many studies have show thatmultiple genes and transcription factors are involved in the process of response tosalt stress in plants. Among them, miRNA, the highly conserved gene regulatoryelements in plants and animals, plays an important role in plants under stress. Betavulgaris is one of the most important sugar crops in China with properties of wideadaptability and strong tolerance to salinity and barren. The seedlings of Betavulgaris can grow in soil containing0.5-0.6%salt and up to0.6-0.8%in growingstage. Therefore, it is important to understand the molecular mechanism of salttolerance and enrich genetic resources for breeding of salt tolerant sugar beet. In thisstudy, conservative miRNA and salt tolerance related miRNA are studied bybioinformatics analysis and validated by techniques of molecular biology.42matured miRNA and23pre-miRNA from14MIR families were predictedafter bioinformatics analysis and used in this study.76target genes were made by40of miRNA, which are involved in the function of growth, signal transduction andstress response n beets.Solexa high-throughput sequencing technology was used to sequence miRNAfrom the leaves of beta vulgaris seedling and there are984redundancy conservative/known miRNA and1,248non-conservative/new miRNA. Sequences from9ofMIR family were the same as before bioinformatic predictions.719differentially expressed miRNA were found after beet seedlings weretreated with300mol/L NaCl in different time intervals. Samples after24h stresstreatment contained most diverse expression of miRNA including428up-regulatedand20down-regulated miRNA. Two of the products, miR160a and miR164a wereused for Taq-man probe which is to detect the quantification of expression. It wasfound that the expressive level of miRNA was incredibly decreased after12h oftreatment and then it was increased following a decrease after that, which isconsistent to the results of Solexa high-throughput sequencing technology.These results indicate that there are substantial conserved miRNA as well as afew specialized miRNA in beets. They play important roles in plant growth anddevelopment, signal transduction, physiological stress response by regulatingregulating related enzymes and transcription factors. This study was to provide datafor miRNA in response to salt stress and the molecular mechanism of salt tolerancein beets.