Aug 2026· Plant physiology and biochemistry : PPB· Vol 238, pp.
111692
· 0 citations· 112 references
Medicine
TL;DR
This work proposes that phytomelatonin functions as an epigenetic and epitranscriptomic trigger capable of converting transient stress perception into durable transcriptional competence and outlines how single-cell multi-omics, targeted epigenome editing, epitranscriptomic profiling and field-scale validation of priming strategies can transform this conceptual framework into testable mechanisms and crop-improvement strategies.
Abstract
Phytomelatonin has long been viewed as a pleiotropic stress signal that protects plants by scavenging reactive oxygen species (ROS), reinforcing antioxidant capacity, and coordinating hormonal responses. That view remains correct, but it is no longer sufficient. Recent work indicates that phytomelatonin also shapes the regulatory architecture that determines whether stress-responsive genes are accessible, whether transcripts are processed and translated efficiently, and whether stress-induced states can persist after the initial stimulus has disappeared. Here, we synthesize four emerging layers of phytomelatonin action: DNA methylation and histone modifications, noncoding RNA (ncRNA) networks, N6 methyladenosine (m6A) RNA methylation and stress memory with potential transgenerational effects. Rather than listing stress phenotypes, we emphasize regulatory logic. Phytomelatonin can buffer stress induced DNA methylation shifts, modulate histone acetylation and methylation marks, rewire microRNA (miRNA), long noncoding RNA (lncRNA) networks and counteract cadmium-induced m6A hypermethylation. Its involvement in circular RNA (circRNA) regulation remains a testable hypothesis. These layers are likely integrated through redox status, hormone crosstalk, RNA stability, chromatin accessibility and DNA repair. We propose that phytomelatonin functions as an epigenetic and epitranscriptomic trigger capable of converting transient stress perception into durable transcriptional competence. Finally, we outline how single-cell multi-omics, targeted epigenome editing, epitranscriptomic profiling and field-scale validation of priming strategies can transform this conceptual framework into testable mechanisms and crop-improvement strategies.
Drought stress is one of the most severe abiotic constraints limiting plant growth, productivity, and global food security, with its impact intensifying under climate change. Plants adapt to drought through complex physiological, transcriptional, and epigenetic regulatory networks. Among these, long non-coding RNAs (lncRNAs) have emerged as critical regulators that integrate transcriptional control with chromatin-level modulation. Once considered transcriptional noise, lncRNAs are now recognised as dynamic molecular regulators that fine-tune drought-responsive gene expression through chromatin remodelling, histone modifications, DNA methylation, RNA-directed DNA methylation (RdDM), and lncRNA-microRNA crosstalk. These mechanisms regulate key adaptive pathways, including abscisic acid (ABA) signalling, reactive oxygen species (ROS) homeostasis, osmotic adjustment, and root system plasticity. Emerging evidence further highlights the role of lncRNAs in epigenetic stress memory, enabling plants to maintain a primed transcriptional state and respond more efficiently to recurrent drought episodes. This review summarises recent advances in the epigenetic functions of lncRNAs in plant drought adaptation, with particular emphasis on chromatin dynamics, stress memory, and lncRNA-mediated regulatory networks. We also discuss insights from integrated omics approaches and highlight the translational potential of drought-responsive lncRNAs for developing climate-resilient crops.
This study examined the complex roles of epigenetic mechanisms—DNA methylation, histone modification, chromatin remodeling, and non-coding RNAs—in enhancing stress tolerance and regulating fruit quality traits.
T. Tejas, Akshay Mehta, S. Baloda et al.· Applied Fruit Science· 0 citations
Summary Hydrogen sulfide (H2S) is a gasotransmitter that contributes to plant stress responses. In this study, we investigated the mechanisms underlying H2S-induced priming in rice drought tolerance. Combining transcriptomic and epigenomic analyses, we show that H2S pretreatment establishes a coordinated regulatory program associated with enhanced stress resilience. H2S attenuated drought-induced transcriptional changes while promoting the expression of dehydrin genes, a hallmark of the primed state. Under non-stress conditions, H2S triggered sustained transcriptional reprogramming, including activation of stress-related transcription factors and repression of cell wall-associated genes. Whole-genome bisulfite sequencing revealed global DNA hypomethylation accompanied by increased CG methylation within gene bodies. Metabolite analyses showed that H2S reduces S-adenosylmethionine levels without affecting S-adenosylhomocysteine, thereby lowering cellular methylation capacity; restoring SAM-reversed DNA hypomethylation. These findings indicate that H2S primes drought tolerance through metabolic control of DNA methylation, linking sulfur signaling to epigenetic regulation.
David Montesinos-Pereira, Jing Zhang, Nazaret Navarro et al.· iScience· 0 citations