水稻盐胁迫相关内含子microRNA的表达及其生物发生机制

Expression and Biological Mechanism of Intronic microRNA under Salt Stress in Rice

内含子microRNA是一类位于编码基因内含子区域的非编码小RNA。目前,动物内含子microRNA研究报道较多,而关于植物体内含子microRNA的功能及其生物发生机制报道较少。本研究通过高通量测序技术,结合生物信息学方法,发现在盐胁迫条件下水稻幼苗中共85个内含子microRNAs表达,其中差异表达的有24个。预测到的51个靶基因的功能分析,主要涉及抗氧化途径、植物激素信号转导途径及功能基因表达调控途径。此外,根据宿主基因的表达情况推测,共30个内含子microRNAs具有独立表达的功能。通过分析内含子microRNA前体DNA片段上游1 kb序列中的启动子核心元件,初步验证其具有独立表达的能力。因此,推测水稻幼苗在盐胁迫条件下,部分内含子microRNA独立于宿主基因表达,并参与水稻盐胁迫下的自我防御机制。

Currently,the studyies of the function and biological mechanism of intronic miRNA are mainly focus on animal,rather than plant. In this study,through high-throughput sequencing and bioinformatics methods,we totally found 85 intronic microRNAs expressed in rice seedlings under salt stress,including 24 differentially expressed intronic microRNA. The functions of 51 predicted target genes were mainly involved in antioxidant process,plant hormone signal introductions and functional genes expression. According to the expression of the host genes,30 intronic microRNAs were expressed independently. The core promoter element analysis of the preliminary DNA upstream 1Kb sequence was conducted to verify the biological mechanism of microRNAs. Therefore,we hypothesized that some intronic microRNAs can express without the expression of host genes during the rice seedling and participate in self-defense under salt stress.