MicroRNA: A powerful tool for post-transcriptional gene silencing in plants

摘要

microRNAs (miRNAs) are extensive classes of ~22-nucleotide non-coding double stranded RNAs that regulate gene expression in metazoans. Plant miRNAs were identified by genetic screening, computational approaches, and expressed sequence tag analysis. Post-transcriptional gene silencing (PTGS) in plants is an RNA-degradation mechanism that requires putative RNA-dependent RNA polymerases and RNA helicases. The sequence-specific degradation of RNA is important in the regulation of protein synthesis and in maintaining signaling traffic. Progress in genomic research of different plant species may open the door for discovering novel miRNAs. The rapid advance in our understanding of miRNAs silencing mechanism will greatly contribute to the study of plant functional genomics. Also, a comparative analysis of these genes, including the gene structure, phylogenetic relationship, conserved protein motifs, gene duplications, chromosomal locations and expression pattern among these plants may shed light on plant development pathways and responses to stress. This review summarizes the current progress in understanding the biogenesis, computational methods involved in miRNAs identification, functions of plant miRNAs genes along with shedding light on the bioinformatics challenges that lie ahead. It also gives an account of plant miRNAs and their versatile roles in plant development. The influence of the advances in genome sequencing of stress tolerant plants such as date palm and jojoba will be briefly addressed in relation to miRNA.