Histone acetyltransferases as integrative epigenetic regulators of plant abiotic stress responses

Roles and Mechanisms of Histone Deacetylases in Plant Abiotic Stress Responses

Histone deacetylases (HDACs) are key epigenetic enzymes governing lysine deacetylation. This modification is tightly coupled to cellular redox homeostasis and antioxidant signaling in plants. Plant HDACs are grouped into three subfamilies: RPD3/HDA1, SIR2, and plant-specific HD2. HDACs target both histone residues (e.g., H3K9 and H4K5) and a broad set of non-histone substrates (e.g., transcription factors and metabolic enzymes). Via coordinated chromatin remodeling and non-histone protein modification, HDACs integrate phytohormone signals, reactive oxygen species (ROS) bursts and NAD+ metabolic fluctuations to orchestrate plant abiotic stress responses, balancing antioxidant defense, redox equilibrium and normal growth. This review systematically sorts the divergent stress-response traits, substrate preferences and bidirectional regulatory logic of the three HDAC subfamilies; integrates chromatin-dependent and transcription factor-centered transcriptional branches; and summarizes crosstalk rules between HDAC-mediated deacetylation and other epigenetic marks. We further hierarchically clarify current research bottlenecks spanning basic mechanism dissection, multi-crop validation and field breeding transformation and propose targeted stratified research directions. We further construct a complete regulatory cascade linking environmental stimuli, ROS/ABA/NAD+ signals, HDAC activity and downstream antioxidant/stress gene expression, filling gaps in previous reviews that overlook redox-dependent HDAC functions. This mechanistic framework delivers integrated epigenetic and redox theoretical references for breeding stress-tolerant crops with reinforced antioxidant capacity.

Functions of the plant NuA4-C in shaping developmental gene expression patterns.

Chromatin remodeling plays a central role in regulating plant development and physiology by shaping the gene expression patterns that drive biological processes. Among epigenetic modifications, histone acetylation is particularly relevant as it alters chromatin structure and influences transcriptional activity. MYST-type histone acetyltransferases (HAT) are evolutionarily conserved components of the Nucleosome Acetyltransferase of histone H4 (NuA4) complex, a key regulator that acetylates histones H4, H2A, and the histone variant H2A.Z. Growing evidence supports the presence of a canonical NuA4-C in plants, similar to that described in yeast. In this review, we summarize recent studies that have begun to uncover its broad role in plant biology, highlighting its involvement in diverse processes such as the skoto- to photomorphogenesis switch, chloroplast development, shade avoidance responses, thermomorphogenesis, the vegetative-to-reproductive transition, plant growth, reproduction and hormonal signalling. In addition, we discuss recent advances in understanding the crosstalk of NuA4-C-mediated H4ac and H2A.Z deposition with other chromatin remodeling complexes in plants. Although significant progress has been made, a full understanding of the complex functions remains unavailable. Current evidence indicates that NuA4-C in yeast and TIP60 in humans are central regulators of transcription, acting not only through histone acetylation but also by influencing transcription elongation and RNA splicing, although direct evidence for similar functions in plant NuA4-C still remains limited. This regulatory role might be critical for integrating developmental programs with environmental signalling pathways. While initial insights into the recruitment of NuA4-C to target genes have emerged, further research is needed to clarify how its activity is controlled and modulated in different biological contexts.

Focus on DnaJ protein research from Arabidopsis to crop improvement

A review of recent advances in the structural diversity, evolutionary distribution, and functional specialization of DnaJ proteins across model plants and crops highlights DnaJ proteins as promising molecular targets for crop improvement and climate‐smart agriculture aimed at increasing productivity, stress tolerance, and postharvest performance under changing environmental conditions.

Non-coding RNAs as central regulators of phytohormone signaling in plant abiotic stress responses

Unravelling the Epigenetic Roles of Long Non-Coding RNAs in Plant Drought Resistance.

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.

Smart Scaffolds: How WD40 Proteins Integrate Plant Development, Metabolism, and Stress Adaptation.

A review of WD40 repeat proteins strengthens current findings relating their structural properties, molecular mechanisms, and functional diversity, underscoring their potential as targets for developing stress-resilient, high-yield crops in a changing climate.