Epigenetic insights into an epimutant : from fruit ripening to stress responses.

The epigenetic machinery has received extensive attention due to its involvement in plant growth, development, and adaptation to environmental changes. Recent studies often highlight the epigenetic regulatory network by discussing various epigenetic mutants across various plant species. However, a systemic understanding of essential epigenetic regulatory mechanisms remains limited due to a lack of representative mutants involved in multiple biological processes. (), a spontaneous epimutant isolated from a commercial population, was initially characterized for its role in fruit ripening regulation. fruits exhibit an immature phenotype with yellow skin, attributed to hypermethylation of the () promoter, resulting in the repression of gene expression. In addition to DNA methylation, this process also involves histone modification and microRNA, integrating multiple epigenetic regulatory factors. Interestingly, knockout mutants of display phenotypical distinctions from in fruit ripening, indicating complex genetic and epigenetic control over the non-ripening phenotype in fruits. Accumulating evidence suggests that epimutation is pleiotropic, participating in various biological processes such as Cd stress, Fe deficiency, vivipary, and cell death. Therefore, the epimutant serve as an excellent model for unveiling how epigenetic mechanisms are involved in diverse biological processes. This review paper focuses on recent research advances regarding the epimutant, delving into its complex genetic and epigenetic regulatory mechanisms, with the aim of enhancing our understanding and facilitating the development of high-quality, high-yield crops through epigenetic modification.