Research Progress on DNA Methylation Regulating Flower Bud Differentiation and Flowering Phenotype in Plants

DNA methylation, a key epigenetic modification, plays a critical regulatory role in plant growth and development, particularly during floral development. In various horticultural plants, DNA methylation levels have been shown to dynamically increase or decrease during floral development in response to environmental cues such as temperature, photoperiod, and endogenous phytohormones. These changes primarily modulate the expression of floral integrator genes (e.g., FT, FLC, AP1, MYB), thereby influencing floral bud differentiation, floral sex differentiation, flowering time, petal color and number, and flower senescence. Moreover, exogenous application of DNA methylation inhibitors during floral development reduces global DNA methylation levels, leading to altered flowering time, floral bud differentiation, and flowering-related phenotypes. This review first outlines the regulatory modes of DNA methylation and its effects on plant growth and development. It then summarizes the types and mechanisms of action of DNA methylation inhibitors, with an emphasis on recent advances in understanding how DNA methylation regulates floral bud differentiation, sex differentiation, flowering progression, and floral phenotypes. Overall, this review provides a theoretical foundation for deciphering the molecular mechanisms underlying DNA methylation-mediated floral development and offers practical insights for flowering regulation in agricultural production.