Abstract: miRNA is a kind of non-coding small RNA which plays an important regulatory role in vivo. miRNA mainly regulates gene expression at the post-transcriptional level and involves in various biological processes such as development and stress tolerance. High-throughput sequencing is one of the most effective methods for the identification of miRNA in plants. The total RNA was extracted from roots, stems and leaves from rice treated with high salt stress. Small RNAs were isolated to construct sRNA libraries. The libraries were sequenced using high-throughput method, and the miRNA expression profiles were analyzed. The results showed that 248 known miRNA from 132 different families were detected in all samples. Totally, 31 differentially expressed miRNAs were identified in root, 11 in stem and 9 in leaf, which belonged to 29 miRNA families, targeting 592 functional genes. Five differentially expressed miRNAs, responding stress tolerance, were further analyzed. The results showed that Osa-miR166h and miR166k were up-regulated, and miR169h and miR530 were down-regulated. The miR169 target genes were investigated using qPCR, and three of four target genes were up-regulated with miR169 down-regulation. Above results indicated that miRNA played an important role in plants stress tolerance.

Key words: miRNA, expression profile, salt stress, rice

摘要： miRNA是生物体内起重要调控作用的一类非编码小RNA分子，在转录后水平调控基因表达，参与生长发育、抗逆等生物学过程。高通量测序法是鉴定植物中miRNA最有效的方法之一。提取盐胁迫处理不同时间的水稻根、茎和叶部的总RNA，从中分离18~30 nt小分子RNA构建文库，进行高通量测序，对miRNA表达谱特性进行了分析。结果表明，所有样品共检测到248个已知的miRNA，来源于132个不同的家族，根、茎、叶中分别有31、11、9个差异表达miRNA，分属于29个家族，靶向592个功能基因，并对其中5个差异显著且与非生物胁迫相关的重要miRNA进行了qPCR分析检测，结果显示Osa-miR166h、Osa-miR166k上调表达，Osa-miR169h、Osa-miR530下调表达，针对Osa-miR169h的4个靶基因进一步定量检测，其中的3个靶基因上调表达，这与Osa-miR169h的下调表达结果相一致，以上结果说明miRNA在植物抵御非生物逆境胁迫的过程中扮演重要角色。

关键词: miRNA, 表达谱, 盐胁迫, 水稻