Abstract
Heavy metal and metalloid stress, particularly from toxic elements like cadmium (Cd), poses a growing threat to plant ecosystems, crop productivity, and global food security. Elevated concentrations of these contaminants can trigger cytotoxic and genotoxic effects in plants, severely impairing growth, development, and reproduction. In recent years, epigenetic mechanisms have emerged as crucial regulators of plant responses to heavy metal stress, offering novel insights and strategies for enhancing plant resilience in contaminated environments. This review synthesises current advances in the field of plant epigenetics, focusing on key modifications such as DNA methylation, histone acetylation and remodelling, chromatin dynamics, and small RNA-mediated regulation. These processes not only influence gene expression under metal-induced stress but also hold promise for long-term adaptation through transgenerational epigenetic memory. Recent developments in high-throughput sequencing and functional genomics have accelerated the identification of epigenetic markers associated with stress tolerance, enabling the integration of these markers into breeding programs and targeted epigenome editing strategies. Special attention is given to cadmium stress responses, where specific epigenetic traits have been linked to enhanced tolerance. As plant epigenomic research progresses, its application in sustainable agriculture becomes increasingly evident offering environmentally friendly solutions to mitigate the impact of heavy metal pollution. This review provides a foundation for future research aimed at leveraging epigenetic tools to engineer crops capable of thriving under metal stress, thereby contributing to resilient agricultural systems and sustainable food production.