The Control of Developmental Phase Transitions by microRNAs and Their Targets in Seed Plants.

Shibiao Liu,Jingyi Ma,Huihong Guo,Pan Zhao,Qi Yang

doi:10.3390/ijms21061971

Abstract

Seed plants usually undergo various developmental phase transitions throughout their lifespan, mainly including juvenile-to-adult and vegetative-to-reproductive transitions, as well as developmental transitions within organ/tissue formation. MicroRNAs (miRNAs), as a class of small endogenous non-coding RNAs, are involved in the developmental phase transitions in plants by negatively regulating the expression of their target genes at the post-transcriptional level. In recent years, cumulative evidence has revealed that five miRNAs, miR156, miR159, miR166, miR172, and miR396, are key regulators of developmental phase transitions in plants. In this review, the advanced progress of the five miRNAs and their targets in regulating plant developmental transitions, especially in storage organ formation, are summarized and discussed, combining our own findings with the literature. In general, the functions of the five miRNAs and their targets are relatively conserved, but their functional divergences also emerge to some extent. In addition, potential research directions of miRNAs in regulating plant developmental phase transitions are prospected.

Highlights

The life cycle of seed plants is composed of a succession of distinct developmental phases, mainly including vegetative growth, reproductive growth, seed/embryo set [1]
The decreased miR159 level regulated by miR167 up-regulated the expression of an MYB33-like gene, which was in line with the late flowering of tobacco [35]
Considering these findings, should miR159 be termed as negative or positive regulator in controlling the vegetative-to-reproductive transition? These conflicting reports might be explained if we assume that miR159 has multiple targets that are involved in different regulatory pathways, controlling flowering time, and the downstream targets of miR159 could be negative or positive regulators of flowering. miR159 was involved in flower, embryo, seed and fruit development in plants

Summary

Introduction

The life cycle of seed plants is composed of a succession of distinct developmental phases, mainly including vegetative growth, reproductive growth, seed/embryo set [1]. The members of the miR159 family regulate developmental phase transitions by targeting MYB transcription factor genes in plants [15,29]. The MiR159-MYB33 module was originally found to control the transition from vegetative to reproductive in Arabidopsis, and elevated miR159 expression of the down-regulated gibberellin (GA)-specific MYB33 level, which reduced a flowering promoter LEAFY activity and delayed flowering time [30].

Results

Conclusion