Elevated concentrations of heavy metals such as cadmium (Cd) have a negative impact on staple crop production due to their ability to elicit cytotoxic and genotoxic effects on plants. In order to understand the relationship between Cd stress and plants in an effort to improve Cd tolerance, studies have identified genetic mechanisms which could be important for conferring stress tolerance. In recent years epigenetic studies have garnered much attention and hold great potential in both improving the understanding of Cd stress in plants as well as revealing candidate mechanisms for future work. This review describes some of the main epigenetic mechanisms involved in Cd stress responses. We summarize recent literature and data pertaining to chromatin remodeling, DNA methylation, histone acetylation and miRNAs in order to understand the role these epigenetic traits play in cadmium tolerance. The review aims to provide the framework for future studies where these epigenetic traits may be used in plant breeding and molecular studies in order to improve Cd tolerance.
Keywords: DNA methylation; cadmium; chromatin; gene expression and histone acetylation.