Uncovering the Epigenetic Marks Involved in Mediating Salt Stress Tolerance in Plants

Abstract

The toxic effects of salinity on agricultural productivity necessitate development of salt stress tolerance in food crops in order to meet the escalating demands. Plants use sophisticated epigenetic systems to fine-tune their responses to environmental cues. Epigenetics is the study of heritable, covalent modifications of DNA and histone proteins that regulate gene expression without altering the underlying nucleotide sequence and consequently modify the phenotype. Epigenetic processes such as covalent changes in DNA, histone modification, histone variants, and certain non-coding RNAs (ncRNA) influence chromatin architecture to regulate its accessibility to the transcriptional machinery. Under salt stress conditions, there is a high frequency of hypermethylation at promoter located CpG sites. Salt stress results in the accumulation of active histones marks like H3K9K14Ac and H3K4me3 and the downfall of repressive histone marks such as H3K9me2 and H3K27me3 on salt-tolerance genes. Similarly, the H2A.Z variant of H2A histone is reported to be down regulated under salt stress conditions. A thorough understanding of the plasticity provided by epigenetic regulation enables a modern approach to genetic modification of salt-resistant cultivars. In this review, we summarize recent developments in understanding the epigenetic mechanisms, particularly those that may play a governing role in the designing of climate smart crops in response to salt stress.

Identification and analysis of proline-rich proteins and hybrid proline-rich proteins super family genes from Sorghum bicolor and their expression patterns to abiotic stress and zinc stimuli

“…DNA and chromatin modifications modulate the expression of stress-responsive genes. Such modifications are also heritable inferring their role in the evolutionary mechanisms associated with abiotic stress tolerance ( Singroha et al, 2022 ).…”

Effects of Salinity Stress on Growth and Physiological Parameters and Related Gene Expression in Different Ecotypes of Sesuvium portulacastrum on Hainan Island

“…Soil salinity, a significant abiotic stressor, has a notable influence on plant growth and crop yields. The stress caused by salinity can greatly impact global food production [41,42]. To date, around 10% of the Earth's overall land area (equivalent to 950 million hectares), 20% of its arable land (about 300 million hectares), and 50% of the total irrigated land (around 230 million hectares) have been impacted by soil salinization.…”

Dynamic regulation of DNA methylation and histone modifications in response to abiotic stresses in plants

“…In alfalfa ( Medicago sativa ), the DNA methylation level increased across the entire genome under salt stress, especially under high salt stress (Al‐Lawati et al, 2016). DNA methylation in promoter regions generally alters the expression level of genes including those involved in the salt stress response (Singroha et al, 2022). HIGH‐AFFINITY K + TRANSPORTER (HKT), which mediates Na + /K + transport, is a major player in plant salt tolerance (Hamamoto et al, 2015).…”