Multifaceted Chromatin Structure and Transcription Changes in Plant Stress Response.

Jin-Hong Kim

doi:10.3390/ijms22042013

Abstract

Sessile plants are exposed throughout their existence to environmental abiotic and biotic stress factors, such as cold, heat, salinity, drought, dehydration, submergence, waterlogging, and pathogen infection. Chromatin organization affects genome stability, and its dynamics are crucial in plant stress responses. Chromatin dynamics are epigenetically regulated and are required for stress-induced transcriptional regulation or reprogramming. Epigenetic regulators facilitate the phenotypic plasticity of development and the survival and reproduction of plants in unfavorable environments, and they are highly diversified, including histone and DNA modifiers, histone variants, chromatin remodelers, and regulatory non-coding RNAs. They contribute to chromatin modifications, remodeling and dynamics, and constitute a multilayered and multifaceted circuitry for sophisticated and robust epigenetic regulation of plant stress responses. However, this complicated epigenetic regulatory circuitry creates challenges for elucidating the common or differential roles of chromatin modifications for transcriptional regulation or reprogramming in different plant stress responses. Particularly, interacting chromatin modifications and heritable stress memories are difficult to identify in the aspect of chromatin-based epigenetic regulation of transcriptional reprogramming and memory. Therefore, this review discusses the recent updates from the three perspectives—stress specificity or dependence of transcriptional reprogramming, the interplay of chromatin modifications, and transcriptional stress memory in plants. This helps solidify our knowledge on chromatin-based transcriptional reprogramming for plant stress response and memory.

Highlights

The chromatin structure in eukaryotic cells contributes to genome stability and displays dynamics to counter endogenous or exogenous stress factors, and neighboring chromatin structures may influence local nucleosome positions and gene expression [1,2,3,4]
The latest studies show that chromatin-based transcriptional regulation is important for both immediate response and future memory in relation to plant stress response; multifaceted epigenetic regulation of stress response and memory in plants is still elusive
Increased practical approaches are being attempted for enhancing plant stress tolerance through chromatin-based epigenetic regulation of transcriptional reprogramming and memory

Summary

Introduction

The chromatin structure in eukaryotic cells contributes to genome stability and displays dynamics to counter endogenous or exogenous stress factors, and neighboring chromatin structures may influence local nucleosome positions and gene expression [1,2,3,4]. Chromatin dynamics are epigenetically regulated by such things as histone variants, histone modifications, DNA (de-)methylation, nucleosome remodeling, and regulatory RNA, such as non-coding RNA (ncRNA), and are related to structural changes of nucleosomes or chromatin, which may affect genome-wide or locus-specific gene expression [5,6,7]. Plants are inevitably exposed to various environmental stress factors, including cold, heat, salinity, drought, dehydration, submergence, waterlogging, and pathogen infection, throughout their lifetimes. To counter these, they are able to develop elaborated structural changes in chromatin and coordinate alterations in histone modification and DNA methylation for the expression of stress-responsive genes [1,2]. Sci. 2021, 22, 2013 there is a need to update the available information on chromatin-based regulation of stress-responsive transcription and stress adaptation and memory in plants

Chromatin Modification and Epigenetic Regulation in Plants

Concluding Remarks and Perspectives