Changes in epigenetic features in legumes under abiotic stresses

Abstract

Legume crops are rich in nutritional value for human and livestock consumption. With global climate change, developing stress‐resilient crops is crucial for ensuring global food security. Because of their nitrogen‐fixing ability, legumes are also important for sustainable agriculture. Various abiotic stresses, such as salt, drought, and elevated temperatures, are known to adversely affect legume production. The responses of plants to abiotic stresses involve complicated cellular processes including stress hormone signaling, metabolic adjustments, and transcriptional regulations. Epigenetic mechanisms play a key role in regulating gene expressions at both transcriptional and posttranscriptional levels. Increasing evidence suggests the importance of epigenetic regulations of abiotic stress responses in legumes, and recent investigations have extended the scope to the epigenomic level using next‐generation sequencing technologies. In this review, the current knowledge on the involvement of epigenetic features, including DNA methylation, histone modification, and noncoding RNAs, in abiotic stress responses in legumes is summarized and discussed. Since most of the available information focuses on a single aspect of these epigenetic features, integrative analyses involving omics data in multiple layers are needed for a better understanding of the dynamic chromatin statuses and their roles in transcriptional regulation. The inheritability of epigenetic modifications should also be assessed in future studies for their applications in improving stress tolerance in legumes through the stable epigenetic optimization of gene expressions.

Multi-Omics Pipeline and Omics-Integration Approach to Decipher Plant’s Abiotic Stress Tolerance Responses

“…Alternatively, epigenetics also refer to the changes in gene activity without any alteration in DNA sequence. Epigenetic mechanisms result in the modification of chromatin structure which regulates mRNA accumulation at the transcriptional level [ 193 ]. Recent research showed that epigenetic mechanisms play a critical role in the regulation of plant genes’ expression under various abiotic stress conditions [ 194 , 195 ].…”

“…Recent research showed that epigenetic mechanisms play a critical role in the regulation of plant genes’ expression under various abiotic stress conditions [ 194 , 195 ]. Changes in environmental factors such as temperature, day length, ultraviolet (UV) radiation, availability of water and soil salinity in plants lead to modifications in the (de)methylation pattern of the coding regions in many stress-responsive genes which consequently regulate their expression [ 193 , 194 , 195 , 196 ]. Nevertheless, in addition to DNA methylation, recent evidence showed that histone modification, small regulatory RNA (sRNA) and long non-coding RNA (lncRNA) associated regulatory pathways are other adaptive mechanisms that regulate gene expression under stress conditions [ 197 ].…”

“…NCED3 (NINE CISEPOXYCAROTENOID DIOXYGENASE 3) is a well-reported gene that responds to ABA synthesis under water scarcity conditions. Accumulation of H3K4me3 in NCED3 gene regions helps with drought resistance in plants accompanied by NCED3 gene expression [ 193 ]. Overall histone modification is a complicated process that plays an important role in epigenetic regulation.…”

Beyond transcription factors: more regulatory layers affecting soybean gene expression under abiotic stress

“…Epigenetic regulation includes a complex network of interchangeable components such as histone variants, chromatin remodeling complexes, and non-coding RNAs. Moreover, histone post-translational modifications and DNA methylation, which modify chromatin configuration and DNA accessibility to regulate transcription without altering the coding sequences, have been well documented, and we will explore them in this review ( Richards, 2011 ; Ali et al, 2022 ; Yung et al, 2022 ).…”