The Construction Of MiRNA Libraries Of The Root Of Halostachys Caspica Under High Salt-stress And Expression Analysis Of MiR398and MiR395

Currently, the global soil salinization is an increasingly serious problem.On theone hand, it brings great pressure to the balance of the ecosystem. On the other hand,it can harm seriously the area of cultivated soil which is becoming the majorenvironmental problems influencing the plant growth, development and restrictingagricultural development of plants. How to improve land salinization is becomecommon concern.The halophyte Halostachys caspica is an extremely salt-tolerant shrub belongingto Chenopodiaceae grown in saline and alkaline desert region. It can be used as agood forage grass in Xinjiang arid region. It has a wide range of economic, medicinaland ecological values. This species is mainly distributed in the Taklamakan desert,Turpan basin in Xinjiang and other regions.MiRNA is widespreadly distributed in eukaryotes about22nt of non-coding smallRNAs, it can regulate the expression of target genes by carrying the target mRNAcleavage or inhibiting the target mRNA translation. MiRNA are widespreadly existingin a variety of plants and has very extensive and important role at plant growthdevelopment and stress resistance.At present, the plant miRNA research is focused on the plant gene expression andgrowth development and so on, and studies of miRNAs in halophytes are less. Inthese relative mechanisms that plants responsing to the stress resistance, most miRNAresearch is involved in the patterns and differences of the miRNA gene expression in avariety of abiotic stress, the related studies of the miRNA and its corresponding totarget gene are still lack.In this manuscript, the root of H. caspica as the research material, miRNA libraryof H. caspica under the high salt stress(treated the plants under600mM NaCl for48h) was established by high-throughput sequencing technology. Primary analysis wascarried between two libraries. By comparing the miRNA expression between the twocontrolled and treated libraries, we screened some differential miRNAs and two kinds of miRNA (miR398and miR395) were choosed as further research to detect theirrelativity on bioinformatic analysis and expression pattern between miR398, miR395and their target genes (CSD1,CSD2and APS1). Then, the full length sequence of thetarget genes CSD1,CSD2and APS1were obtained by homology cloning method, andthe possible relation can be preliminary conformed between miR398, miR395and itstarget genes using the bioinformatics software. Finally, By real-time quantitative PCRmethod analyzed expression patterns of miR398and miR395were carried under highsalt stress(treated the plants of H. caspica at different time courses under600mMNaCl). These results can provide a good foundation for furthering to study andcomprehensive the salt-tolerant mechanism of H. caspica.