Dynamics and Malleability of Plant DNA Methylation During Abiotic Stresses.

Epigenetic regulation, particularly DNA methylation, plays a crucial role in plant adaptation to environmental stresses by modulating gene expression without altering the underlying DNA sequence. In response to major abiotic stresses such as salinity, drought, heat, cold, and heavy metal toxicity, plants undergo dynamic changes in DNA methylation patterns. These modifications are orchestrated by DNA methyltransferases and demethylases with variations depending on plant species, genetic background, and ontogenic phase. DNA methylation affects the expression of key genes involved in cellular, physiological, and metabolic processes essential for stress tolerance. Furthermore, it contributes to the establishment of stress memory, which can be transmitted across generations, thereby enhancing long-term plant resilience. The interaction of DNA methylation with other epigenetic mechanisms, including histone modifications, small RNAs, and chromatin remodeling, adds layers of regulatory complexity. Recent discoveries concerning N6-methyladenine have opened new avenues for understanding the epigenetic landscape in plant responses to abiotic stress. Overall, this review addresses the central role of DNA methylation in regulating plant stress responses and emphasizes its potential for application in crop improvement through epigenetic and advanced biotechnological approaches.