Kumar Rajesh
Department of Internal Medicine I and Clinical Chemistry, Im Neuenheimer Feld 410, University of Heidelberg, Heidelberg, 69120, Germany,
Appl Biochem Biotechnol. 2014 Sep;174(1):93-115. doi: 10.1007/s12010-014-0914-2. Epub 2014 May 29.
MicroRNAs (miRNAs) are small non-coding endogenous RNAs (18-24 nucleotides) which regulate gene expression at posttranscriptional level either by degrading the target mRNA (plants) or by blocking the protein translation through binding with 3' UTR of the target mRNA (animals). Though miRNAs are known to play key roles in animal development, miRNAs that are involved in plant developmental timing, cell proliferation, and several other physiological functions need to be investigated. In addition, plant miRNAs have been shown to be involved in various biotic (bacterial and viral pathogenesis) and abiotic stress responses such as oxidative, mineral nutrient deficiency, drought, salinity, temperature, cold (chilling), and other abiotic stress. miRNA expression profiling reveals that miRNAs which are involved in the progression of plant growth and development are differentially expressed during abiotic stress responses. The high-throughout techniques can provide genome-wide identification of stress-associated miRNAs under various abiotic stresses in plants. Various web-based and non-web-based computational tools facilitate in the identification and characterization of biotic/abiotic stress associated miRNAs and their target genes. In the future, miRNA-mediated RNA interference (RNAi) approach might help in developing transgenic crop plants for better crop improvement by conferring resistance against biotic (pathogens) as well as abiotic stress responses.
微小RNA（miRNA）是一类小的非编码内源性RNA（18 - 24个核苷酸），它们通过降解靶标mRNA（植物中）或通过与靶标mRNA的3'非翻译区结合来阻断蛋白质翻译（动物中），从而在转录后水平调节基因表达。尽管已知miRNA在动物发育中起关键作用，但参与植物发育时间调控、细胞增殖及其他多种生理功能的miRNA仍有待研究。此外，植物miRNA已被证明参与各种生物（细菌和病毒致病过程）和非生物胁迫反应，如氧化胁迫、矿质营养缺乏、干旱、盐度、温度、冷害（低温）及其他非生物胁迫。miRNA表达谱分析表明，参与植物生长和发育进程的miRNA在非生物胁迫反应中差异表达。高通量技术能够在植物各种非生物胁迫下对与胁迫相关的miRNA进行全基因组鉴定。各种基于网络和非基于网络的计算工具有助于鉴定和表征与生物/非生物胁迫相关的miRNA及其靶基因。未来，miRNA介导的RNA干扰（RNAi）方法可能有助于培育转基因作物，通过赋予对生物（病原体）和非生物胁迫反应的抗性来更好地改良作物。
