MicroRNA and Transcription Factor: Key Players in Plant Regulatory Network

Abstract

Recent achievements in plant microRNA (miRNA), a large class of small and non-coding RNAs, are very exciting. A wide array of techniques involving forward genetic, molecular cloning, bioinformatic analysis, and the latest technology, deep sequencing have greatly advanced miRNA discovery. A tiny miRNA sequence has the ability to target single/multiple mRNA targets. Most of the miRNA targets are transcription factors (TFs) which have paramount importance in regulating the plant growth and development. Various families of TFs, which have regulated a range of regulatory networks, may assist plants to grow under normal and stress environmental conditions. This present review focuses on the regulatory relationships between miRNAs and different families of TFs like; NF-Y, MYB, AP2, TCP, WRKY, NAC, GRF, and SPL. For instance NF-Y play important role during drought tolerance and flower development, MYB are involved in signal transduction and biosynthesis of secondary metabolites, AP2 regulate the floral development and nodule formation, TCP direct leaf development and growth hormones signaling. WRKY have known roles in multiple stress tolerances, NAC regulate lateral root formation, GRF are involved in root growth, flower, and seed development, and SPL regulate plant transition from juvenile to adult. We also studied the relation between miRNAs and TFs by consolidating the research findings from different plant species which will help plant scientists in understanding the mechanism of action and interaction between these regulators in the plant growth and development under normal and stress environmental conditions.

Keywords: miRNAs; plant development; plant regulators; stress response; transcription factors.

FIGURE 1

Interaction between different microRNAs (miRNAs) and transcription factors (TFs) in plant development under normal condition. Interaction between miR156-SPL and miR172-AP2 leads plant transition from juvenile to adult; miR156-SPL, miR172-AP2, and miR319-TCP regulate the flowering process; miR319-TCP and miR396-GRF control leaf morphogenesis; miR169-NY-FA and miR164-NAC1 regulate root development and nodule formation, and miR166-HD ZIP III responsible for shoot apical meristem (SAM) development and organ polarity.

FIGURE 2

Interaction between different miRNAs and TFs in plant under stresses. Stresses (biotic and abiotic) induce signal transduction which led to activation of stress responsive miRNAs (miR159, miR169, miR828, miR858, miR164, miR319, and miR396) and/or their target TFs (NF-YA, MYB, NAC, WRKY, and TCP) that can affect the target genes. miRNA can regulate target gene directly (post-transcriptionally as shown with dotted line) or through TF by regulating TF (Transcriptionally as shown with solid line) that involve in the regulation of target gene. TFs can directly regulate target gene or through miRNA that involve in the regulation of target gene.