School of Biotechnology, Presidency University (Rajarhat Campus), Canal Bank 7 Road, DG Block, Action Area 1D, Newtown, Kolkata, West Bengal, 700156, India.
Plant Cell Rep. 2021 May;40(5):783-798. doi: 10.1007/s00299-020-02660-7. Epub 2021 Jan 16.
miRNAs in plant plays crucial role in controlling proper growth, development and fitness by modulating the expression of their target genes. Therefore to modulate the expression of any stress/development related gene specifically, it is better to modulate expression of the miRNA that can target that gene. To modulate the expression level of miRNA, it is prerequisite to uncover the underlying molecular mechanism of its biogenesis. The biogenesis pathway consists of two major steps, transcription of MIR gene to pri-MIRNA and processing of pri-MIRNA into mature miRNA via sequential cleavage steps. Both of these pathways are tightly controlled by several different factors involving structural and functional molecules. This review is mainly focused on different aspects of pri-MIRNA processing mechanism to emphasize on the fact that to modulate the level of a miRNA in the cell only over-expression or knock-down of that MIR gene is not always sufficient rather it is also crucial to take processing regulation into consideration. The data collected from the recent and relevant literatures depicts that processing regulation is controlled by several aspects like structure and size of the pri-MIRNA, presence of introns in MIR gene and their location, interaction of processing factors with the core components of processing machinery etc. These detailed information can be utilized to figure out the particular point which can be utilized to modulate the expression of the miRNA which would ultimately be beneficial for the scientist and researcher working in this field to generate protocol for engineering plant with improved yield and stress tolerance.
miRNAs 在植物中通过调节靶基因的表达在控制正常生长、发育和适应性方面起着至关重要的作用。因此，为了专门调节任何与应激/发育相关的基因的表达，最好调节可以靶向该基因的 miRNA 的表达。为了调节 miRNA 的表达水平，首先必须揭示其生物发生的潜在分子机制。生物发生途径由两个主要步骤组成，即 MIR 基因转录为 pri-MIRNA 以及通过连续切割步骤将 pri-MIRNA 加工为成熟 miRNA。这两个途径都受到涉及结构和功能分子的几个不同因素的严格控制。这篇综述主要集中在 pri-MIRNA 加工机制的不同方面，强调一个事实，即要调节细胞中 miRNA 的水平，仅过表达或敲低该 MIR 基因并不总是足够的，还必须考虑加工调节。从最近和相关文献中收集的数据表明，加工调节受到多个方面的控制，例如 pri-MIRNA 的结构和大小、MIR 基因中内含子的存在及其位置、加工因子与加工机制核心组件的相互作用等。这些详细信息可用于找出可用于调节 miRNA 表达的特定点，这对于从事该领域研究的科学家和研究人员最终将有助于生成具有改良产量和应激耐受性的工程植物的方案。
