The Important Function of Mediator Complex in Controlling the Developmental Transitions in Plants.

Changkui Guo,Lingjie Zhang

doi:10.3390/ijms21082733

Changkui Guo, Lingjie Zhang

Open Access

https://doi.org/10.3390/ijms21082733

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Abstract

Developmental transitions in plants are tightly associated with changes in the transcriptional regulation of gene expression. One of the most important regulations is conferred by cofactors of RNA polymerase II including the mediator complex, a large complex with a modular organization. The mediator complex recruits transcription factors to bind to the specific sites of genes including protein-coding genes and non-coding RNA genes to promote or repress the transcription initiation and elongation using a protein-protein interaction module. Mediator complex subunits have been isolated and identified in plants and the function of most mediator subunits in whole life cycle plants have been revealed. Studies have shown that the Mediator complex is indispensable for the regulation of plant developmental transitions by recruiting age-, flowering-, or hormone-related transcription factors. Here, we first overviewed the Mediator subunits in plants, and then we summarized the specific Mediator subunits involved in developmental transitions, including vegetative phase change and floral transition. Finally, we proposed the future directions to further explore their roles in plants. The link between Mediator subunits and developmental transitions implies the necessity to explore targets of this complex as a potential application in developing high quality crop varieties.

Highlights

As sessile organisms, plants are able to adapt to changes around them, including decrease of nutrient and water content, increase of salt content in soil, or changeable temperature and light intensity [1]
The von Willenbrand factor type a (vWFA) domain strengthens the communion between MED25 and other Mediator subunits, and the ACID domain can bind transcription factors [16,17]
Based on the important function of jasmonic acid (JA) signaling in vegetative phase change, whether MED25 plays a role in the regulation of vegetative phase change needs to be studied further

Summary

Introduction

Plants are able to adapt to changes around them, including decrease of nutrient and water content, increase of salt content in soil, or changeable temperature and light intensity [1]. MED7, MED9, gene-specific transcription factors; thefunction middle module subunits, including. Mediator shows that the MED14 subunit that connects the head, middle and tail modules. The Mediator complex with high-homology sequences (MED domain) (Table S1) has conserved function by interacting with RNAP II. The vWFA domain strengthens the communion between MED25 and other Mediator subunits, and the ACID domain can bind transcription factors [16,17] These findings indicate that MED sequences have no high identity, but different domains contain similar structures for interacting with their partners. To understand the functional mechanism of the Mediator complex in plant development, an interaction map and a probable structural topology of the Arabidopsis Mediator complex were constructed (Figure 1B). We speculate that the specialized function of the mediator complex in different eukaryotes might be caused by the differences in the interaction map of Mediator subunits

Functions in Vegetative Phase Change in Plants

Functions in Floral Transition

Perspectives