DNA methylation, an evolutionarily conserved epigenetic mechanism, is crucial for controlling gene activity and ensuring genomic integrity. Altered methylation patterns can profoundly affect plant development, often resulting in atypical phenotypes. The regulation of these methylation states relies on the coordinated actions of de novo methylation, maintenance, and active demethylation, orchestrated by specialized enzymes within distinct pathways. This review delves into the diverse roles of DNA methylation in plants, offering an in-depth analysis of the enzymes and regulatory factors involved. We explore how these elements function within the broader epigenetic framework, focusing on their contributions to silencing transposable elements, modulating gene expression, and shaping chromatin architecture. The review also examines the significance of DNA methylation in plant development, particularly its role in adapting to biotic and abiotic stresses. Lastly, we highlight its potential for driving innovations in crop breeding, emphasizing its applicability in advancing sustainable agriculture.

Sweet potato starch is an important source of starch in food processing, but its natural functionality is relatively limited, restricting its performance in certain applications. Gelatinized sweet potato starch, with enhanced structural and functional properties, has broader potential applications in food products. During the gelatinization process, the crystalline structure of sweet potato starch changes, making it suitable for use in various food formulations. Gelatinized sweet potato starch can be produced through techniques such as moist heat processing, extrusion, and spray drying, with the gelatinization effect influenced by factors such as moisture content and temperature. This review summarizes the gelatinization techniques and influencing factors for sweet potato starch, highlighting how structural changes under different conditions affect the quality of the final food products. Understanding these techniques and influencing factors helps optimize the gelatinization process of sweet potato starch, enhancing its application in foods such as noodles and baked goods. This knowledge provides theoretical support and practical guidance for the further utilization of sweet potato starch in the food industry.

DNA methylation is a conserved and vital epigenetic modification that plays essential roles in plant growth, development, and responses to environmental stress. Cytosine-5 DNA methyltransferases (C5-MTases) and DNA demethylases (dMTases) are key regulators of DNA methylation dynamics. However, a comprehensive characterization of these gene families in sweet potato has remained elusive. In this study, we systematically identified and analyzed eight C5-MTase and five dMTase genes in the genomes of diploid (Ipomoea trifida, 2n = 2x = 30) and autohexaploid (Ipomoea batatas, 2n = 6x = 90) sweet potato. Phylogenetic, structural, and synteny analyses revealed a high degree of conservation among these genes, suggesting their essential roles during evolution. Promoter analysis uncovered multiple cis-acting elements, particularly those responsive to light and hormones. In addition, we examined the expression profiling of IbC5-MTases and IbdMTases genes during storage root development, revealing that several were highly expressed during the early and rapid expansion stages. These findings suggest that C5-MTases and dMTases may contribute to the regulation of storage root formation in sweet potato through epigenetic mechanisms, offering valuable insights for future functional studies and epigenetic breeding efforts.