盐、干旱胁迫下水稻相关miRNA的鉴定及表达分析

摘要

To identify the miRNAs and their response regular patterns to salt stress and drought stress,rice seedlings at three leaves stage were used to quantify the expression of miRNAs and their targets when treated with salt and drought stresses at 0,3,6,12,24,48 h by qRT-PCR. The results demonstrated that expression patterns of miRNAs were affected by space-time and tissues under salt and drought treatments. Further analysis indicated that the expressions of miR156,miR164,miR167,miR169, and miR171 upregulated in roots with time and expressions of miR159,miR160,miR319,miR398,and miR1848 downregulated at 3 h and then upregulated when treated with salt (NaCl). And the 10 miRNAs were performed their lowest expressions in shoots at 3 or 6 h under NaCl treat-ment. On the other hand,the expressions of the most of the 10 miRNAs downregulated in roots generally and ex-pressions of miR156,miR159 and miR160 downregulated in shoots and the expression patterns of miR167,miR169, miR319,miR398,and miR1848 down regulated first and then upregulated when treated with drought(PEG). Fur-thermore,expression patterns of targets were also affected by space-time and tissues. And only few expression pat-terns of the 10 miRNAs negatively correlated with its target,which implied the complexity of the regulation network of miRNA and its target in response to stresses.%为鉴定水稻盐和干旱胁迫下相关miRNA及其响应规律,以三叶一心水稻幼苗为材料,采用实时定量PCR的方法研究了盐 (NaCl) 和干旱胁迫(PEG)0,3,6,12,24,48 h后10个miRNA及其靶基因的响应.结果表明,miRNA在盐和干旱胁迫下均存在时序性和组织特异性表达.盐胁迫处理下随处理时间的增加,miR156、miR164、miR167、miR169、miR171在根部的表达量呈上调趋势,miR159、miR160、miR319、miR398、miR1848在处理后3 h呈下调趋势,而后呈上调趋势;且在处理后3 h或6 h时所有miRNA均在地上部的表达量均最低.干旱胁迫处理后,根部miRNA随处理时间的增加基本表现为下降趋势;地上部随处理时间的延长,miR156、miR159、miR160、miR171的表达量呈先下降后维持在较低水平,而miR164、miR167、miR169、miR319、miR398、miR1848的表达量呈下调的趋势.miRNA靶基因的表达也存在明显的组织特异性和时序性,且仅少数miRNA与其靶基因的表达量呈负相关关系,证明miRNA通过调节其靶基因参与植物逆境响应及其调控网络的复杂性.