中文摘要：

蒙古沙冬青（Ammopiptanthus mongolicus）是生长在荒漠中的木本植物,对于我国西北部干旱、半干旱区域的植被维护与恢复具有重要价值。蒙古沙冬青对干旱、低温等多种逆境具有较高的耐受性,是研究林木耐受逆境生理与分子机制的合适材料。MicroRNA（miRNA）是一类长度约为21个核苷酸的内源性非编码小分子RNA,在植物生长发育和逆境应答等生物学过程中发挥着重要的调控作用。目前,许多植物物种的miRNAs已经获得鉴定,但未见蒙古沙冬青miRNAs的相关报道。文章应用高通量测序和生物信息学分析方法对蒙古沙冬青幼苗保守miRNAs的类型、表达丰度以及靶基因进行了分析和预测。共鉴定了10个家族的19种保守miRNAs,其表达丰度介于55~1920269个拷贝之间。通过在线软件psRNATarget预测了其中14个保守miRNAs的靶基因。对于这些靶基因的功能分析表明,蒙古沙冬青的保守 miRNA 主要通过转录调控、激素信号途径、物质代谢和胁迫应答等生物学过程参与植物生长发育和环境响应。

英文摘要：

Ammopiptanthus mongolicus, a woody plant growing in the desert, plays a vital role in vegetation maintaining and restoration in the arid region in northwest China. The plant exhibits an extremely high tolerance to abiotic stress such as drought and freezing stresses, and it has been used as an ideal model for abiotic stress tolerance research in trees. MicroRNA （miRNA） is a class of approximately 21nt endogenous non-protein-coding small RNA, which plays an im-portant role in plant growth, development and responses to environmental stresses. By now, a large number of miRNAs have been reported in many plant species, but no studies describing A.mongolicus miRNA were published. In the present study, the types, expression levels, and putative target genes of conserved miRNAs in seedlings of A. mongolicus were ana-lyzed using small RNA deep sequencing technology and bioinformatics methods. Nineteen conserved miRNAs, which be-long to 10 miRNA families, were identified, with abundance ranging from 55 to 1920269 reads. Target prediction analysis determined the target genes of 14 conserved miRNAs. The functional classification analysis indicated that the conserved miRNAs participate in the development and environmental response by regulating the biological processes including the transcription regulation, hormone signal transduction, metabolisms and stress resistance.