The ‘how’ and ‘where’ of plant microRNAs

Corresponding author: Xuemei Chen

MicroRNAs (miRNAs) are small non-coding RNAs, of typically 20–24 nt, that regulate gene expression post-transcriptionally through sequence complementarity. Since the identification of the first miRNA, lin-4, in the nematode (线虫) Caenorhabditis elegans (秀丽隐杆线虫) in 1993, thousands of miRNAs have been discovered in animals and plants, and their regulatory roles in numerous biological processes have been uncovered. In plants, research efforts have established the major molecular framework of miRNA biogenesis and modes of action, and are beginning to elucidate the mechanisms of miRNA degradation. Studies have implicated restricted and surprising subcellular locations in which miRNA biogenesis or activity takes place. In this article, we summarize the current knowledge on how plant miRNAs are made and degraded, and how they repress target gene expression. We discuss not only the players involved in these processes, but also the subcellular sites in which these processes are known or implicated to take place. We hope to raise awareness that the cell biology of miRNAs holds the key to a full understanding of these enigmatic molecules.

MicroRNA（miRNA）是小的非编码RNA，长度20-24个核苷酸，通过序列互补转录后调控基因的表达。自从1993年第一个miRNA，即秀丽隐杆线虫中的lin-4被鉴定以来，已经有数千个动植物miRNA被发现，同时发现了这些miRNA在许多生物学过程中发挥调控作用。在植物中，miRNA生物合成及其作用模式得到了很好的研究，现在已经开始阐述miRNA的降解机制。目前的研究已经揭示了miRNA生物合成及发挥生物功能的亚细胞定位。本文对目前植物miRNA的生物合成和降解，及这些miRNA如何抑制靶基因表达的研究进展进行了梳理。作者不仅讨论了参与这些进程的因子，同时也对这些进程发生的亚细胞定位进行了讨论。

通讯：Xuemei Chen (http://cepceb.ucr.edu/people/chen.html)

个人简介：1988年，北京大学，学士；1995年，康奈尔大学，博士。

doi: 10.1111/nph.14834