Stress-induced chromatin changes in plants: of memories, metabolites and crop improvement

Abstract

Exposure of plants to adverse environmental conditions leads to extensive transcriptional changes. Genome-wide approaches and gene function studies have revealed the importance of chromatin-level control in the regulation of stress-responsive gene expression. Advances in understanding chromatin modifications implicated in plant stress response and identifying proteins involved in chromatin-mediated transcriptional responses to stress are briefly presented in this review. We then highlight how chromatin-mediated gene expression changes can be coupled to the metabolic status of the cell, since many of the chromatin-modifying proteins involved in transcriptional regulation depend on cofactors and metabolites that are shared with enzymes in basic metabolism. Lastly, we discuss the stability and heritability of stress-induced chromatin changes and the potential of chromatin-based strategies for increasing stress tolerance of crops.

Creating Order from Chaos: Epigenome Dynamics in Plants with Complex Genomes

“…While chromatin states are a critical part of transcriptional responses during development (reviewed in He et al, 2011;Holec and Berger, 2012;Grimanelli and Roudier, 2013;Pikaard and Mittelsten Scheid, 2014;Xiao and Wagner, 2015) or in response to the environment (reviewed in Baulcombe and Dean, 2014;Bond and Baulcombe, 2014;Pikaard and Mittelsten Scheid, 2014;Probst and Mittelsten Scheid, 2015;Vriet et al, 2015), they also play critical roles in creating order in the genome, allowing for the maintenance of proper transcription and genome stability in the face of varying TE landscapes and polyploid changes. We suggest that diverse plant species have evolved variations in the specific mechanisms of chromatin regulation that have allowed them to survive the repeated transposon bursts or polyploidy fusions.…”

“…In some cases, chromatin modifiers are likely to be recruited to achieve and stabilize alterations in transcription. Several recent reviews have provided excellent summaries of these activities and point toward the conservation of these pathways among flowering plants (Baulcombe and Dean, 2014;Bond and Baulcombe, 2014;Pikaard and Mittelsten Scheid, 2014;Probst and Mittelsten Scheid, 2015;Vriet et al, 2015;Xiao and Wagner, 2015). In this Review, we focus on aspects of chromatin regulation that might be variable or drive variation among closely related species.…”

Nutrient stress-induced chromatin changes in plants

“…The capacity of some of these modifications to be stably transmitted through mitosis as well as meiosis led to the hypothesis that changes in chromatin state could serve as stress priming and/or memory mechanisms to prepare future generations to efficiently cope with biotic and abiotic stresses (for review see Refs. [14][15][16][17]). However, to date very few experimentally validated cases of mitotic or meiotic transmission of stress induced changes in chromatin structure have been reported in plants.…”

“…Among these, sophisticated dynamic changes in chromatin structure have been observed in response to numerous environmental conditions, often associated with concomitant changes in gene expression (reviewed in Refs. [9][10][11][12][13][14]). The basic chromatin unit is constituted of 147 base pairs of DNA wrapped around the eight core histones and forms the nucleosome.…”

Salicylic acid interferes with GFP fluorescence in vivo

“…Studying the regulatory pathways of gene activation helps unravel plant responses to abiotic and biotic stresses. Several pathways of plant responses to stress have been discovered during the last few decades, including chromatin-based mechanisms that contribute to abiotic stress responses (Hennig, 2012; Sani et al , 2013; Shen et al , 2014; Mehdi et al , 2015; Vriet et al , 2015). …”