Singh Khushwant, Dardick Chris, Kumar Kundu Jiban
Division of Crop Protection and Plant Health, Crop Research Institute, Prague 161 06, Czech Republic.
United States Department of Agriculture, Agricultural Research Service, Appalachian Fruit Research Station, Kearneysville, WV 25430, USA.
Plants (Basel). 2019 Sep 22;8(10):359. doi: 10.3390/plants8100359.
Small RNAs (sRNAs) are 20-30-nucleotide-long, regulatory, noncoding RNAs that induce silencing of target genes at the transcriptional and posttranscriptional levels. They are key components for cellular functions during plant development, hormone signaling, and stress responses. Generated from the cleavage of double-stranded RNAs (dsRNAs) or RNAs with hairpin structures by Dicer-like proteins (DCLs), they are loaded onto Argonaute (AGO) protein complexes to induce gene silencing of their complementary targets by promoting messenger RNA (mRNA) cleavage or degradation, translation inhibition, DNA methylation, and/or histone modifications. This mechanism of regulating RNA activity, collectively referred to as RNA interference (RNAi), which is an evolutionarily conserved process in eukaryotes. Plant RNAi pathways play a fundamental role in plant immunity against viruses and have been exploited via genetic engineering to control disease. Plant viruses of RNA origin that contain double-stranded RNA are targeted by the RNA-silencing machinery to produce virus-derived small RNAs (vsRNAs). Some vsRNAs serve as an effector to repress host immunity by capturing host RNAi pathways. High-throughput sequencing (HTS) strategies have been used to identify endogenous sRNA profiles, the "sRNAome", and analyze expression in various perennial plants. Therefore, the review examines the current knowledge of sRNAs in perennial plants and fruits, describes the development and implementation of RNA interference (RNAi) in providing resistance against economically important viruses, and explores sRNA targets that are important in regulating a variety of biological processes.
小RNA（sRNA）是长度为20 - 30个核苷酸的调控性非编码RNA，可在转录水平和转录后水平诱导靶基因沉默。它们是植物发育、激素信号传导和应激反应过程中细胞功能的关键组成部分。由双链RNA（dsRNA）或具有发夹结构的RNA被类Dicer蛋白（DCL）切割产生后，它们被加载到Argonaute（AGO）蛋白复合物上，通过促进信使RNA（mRNA）切割或降解、翻译抑制、DNA甲基化和/或组蛋白修饰来诱导其互补靶标的基因沉默。这种调节RNA活性的机制统称为RNA干扰（RNAi），这是真核生物中一个进化上保守的过程。植物RNAi途径在植物抗病毒免疫中起基本作用，并已通过基因工程被用于控制疾病。含有双链RNA的RNA病毒来源的植物病毒被RNA沉默机制靶向，以产生病毒衍生的小RNA（vsRNA）。一些vsRNA通过捕获宿主RNAi途径作为抑制宿主免疫的效应物。高通量测序（HTS）策略已被用于鉴定内源性sRNA图谱，即“sRNA组”，并分析各种多年生植物中的表达。因此，本综述研究了多年生植物和果实中sRNA的现有知识，描述了RNA干扰（RNAi）在提供对经济上重要病毒的抗性方面的发展和应用，并探索了在调节各种生物学过程中重要的sRNA靶标。
