Abstract: To investigate the tissue-specific miRNAs response to drught stress in Bothriochloa ischaemum. Based on the transcriptome data of Bothriochloa ischaemum under drought stress,we used Illumina sequencing and bioinformatics methods to identify and analyze the expression of miRNAs in leaves and roots of Bothriochloa ischaemum seedlings under drought stress and normal growth conditions. Seventy-nine Known miRNAs belonging to 20 families and 92 Novel miRNAs were identified from four libraries. There were 65 miRNAs (28 upregulated and 37 downregulated) and 27 miRNAs (15 upregulated and 12 downregulated) were differentially expressed in leaves and roots after drought stress,respectively. The major miRNAs responding to drought stress were miR156,miR164,miR166,miR169,miR172,miR396,miR398,miR408 and miR528. The enrichment analysis of GO biological function and KEGG metabolic pathway showed that plant hormone signal transduction was the main metabolic pathway in response to drought stress in leaves and roots,and flavonoid biosynthesis was the major rich factor for Bothriochloa ischaemum leaves responding to drought stress.

Key words: Bothriochloa ischaemum, Drought stress, MiRNA, Bioinformatics

摘要： 为了探索干旱胁迫下白羊草miRNAs的组织特异性，本研究在干旱胁迫下白羊草（Bothriochloa ischaemum）转录组数据的基础上，采用Illumina测序技术和生物信息学方法，对干旱胁迫和正常生长条件下白羊草苗期叶片和根系miRNAs（microRNAs）进行鉴定和表达分析研究。结果从4个库中鉴定出白羊草中有属于20个家族的79个已知miRNAs和92个新miRNAs。干旱胁迫后叶片和根系中差异表达的miRNAs分别有65个（上调28和下调37）和27个（上调15和下调12）。响应干旱胁迫的主要miRNAs为miR156，miR164，miR166，miR169，miR172，miR396，miR398，miR408，miR528。对这些miRNAs预测的靶基因进行GO生物功能和KEGG代谢通路富集分析表明，植物激素信号转导是叶片和根系响应干旱胁迫共同富集的主要代谢通路，而黄酮类化合物生物合成则是干旱胁迫下叶片富集的最主要代谢通路。

关键词: 白羊草, 干旱胁迫, MiRNA, 生物信息学