Centre for Plant Science, School of Environmental and Life Sciences, College of Engineering, Science and Environment University of Newcastle, Callaghan, NSW 2308, Australia.
Research School of Biology, Australian National University, Canberra, ACT 2601, Australia.
Genes (Basel). 2024 Aug 7;15(8):1042. doi: 10.3390/genes15081042.
In (), microRNA160 (miR160) regulates the expression of (), and throughout development, including the development of the root system. We have previously shown that in addition to DOUBLE-STRANDED RNA BINDING1 (DRB1), DRB2 is also involved in controlling the rate of production of specific miRNA cohorts in the tissues where is expressed in wild-type plants. In this study, a miR160 overexpression transgene () and miR160-resistant transgene versions of and ( and ) were introduced into wild-type plants and the and single mutants to determine the degree of requirement of DRB2 to regulate the miR160 expression module as part of root development. Via this molecular modification approach, we show that in addition to DRB1, DRB2 is required to regulate the level of miR160 production from its precursor transcripts in roots. Furthermore, we go on to correlate the altered abundance of miR160 or its , and target genes in the generated series of transformant lines with the enhanced development of the root system displayed by these plant lines. More specifically, promotion of primary root elongation likely stemmed from enhancement of miR160-directed expression repression, while the promotion of lateral and adventitious root formation was the result of an elevated degree of miR160-directed regulation of expression, and to a lesser degree, and expression. Taken together, the results presented in this study identify the requirement of the functional interplay between DRB1 and DRB2 to tightly control the rate of miR160 production, to in turn ensure the appropriate degree of miR160-directed , and gene expression regulation as part of normal root system development in .
在（）中，microRNA160（miR160）调节（）的表达，包括根系的发育。我们之前已经表明，除了双链 RNA 结合蛋白 1（DRB1）之外，DRB2 还参与控制在野生型（）植物中表达的组织中特定 miRNA 簇的产生速度。在这项研究中，引入了 miR160 过表达转基因（）和 miR160 抗性转基因版本的（和）（和）到野生型（）植物和（和）单突变体中，以确定 DRB2 调节 miR160 表达模块作为根系发育的一部分的程度。通过这种分子修饰方法，我们表明，除了 DRB1 之外，DRB2 还需要调节 miR160 从其前体转录本产生的水平。此外，我们继续将生成的一系列转化株系中 miR160 或其、和靶基因的丰度变化与这些植物株系显示的增强的根系发育相关联。更具体地说，初级根伸长的促进可能源于 miR160 指导的表达抑制的增强，而侧根和不定根的形成的促进是由于 miR160 指导的表达调控程度的提高，以及在较小程度上，和表达的提高。总之，本研究结果表明，DRB1 和 DRB2 之间功能相互作用的需求，以紧密控制 miR160 产生的速度，从而确保 miR160 指导的、和基因表达调控的适当程度，作为正常根系发育的一部分在中。
