The mechanistic insights into fruit ripening: integrating phytohormones, transcription factors, and epigenetic modification.

Fruit ripening is a complex developmental process tightly regulated by hormonal crosstalk, transcriptional networks, and epigenetic modifications, with striking divergence between climacteric and non-climacteric species. In climacteric fruits, such as tomatoes, apples, and bananas, ethylene acts as the master regulator, driving autocatalytic biosynthesis through ACS/ACO genes and activating hierarchical transcriptional cascades mediated by MADS-box (RIN), NAC (NOR), and ERF-family transcription factors. These pathways are amplified by epigenetic reprogramming, including DNA demethylation at ripening-related promoters and histone acetylation, which enhance chromatin accessibility to facilitate gene expression. Conversely, non-climacteric fruits like strawberries and grapes predominantly rely on abscisic acid (ABA) to coordinate ripening. Hormonal interplay-such as ethylene-ABA synergy in climacteric fruits systems-further fine-tunes ripening dynamics. Advances in CRISPR-based gene editing and epigenome engineering now enable precise manipulation of these pathways, offering transformative solutions to reduce postharvest losses, enhance nutritional quality, and improve climate resilience. This review integrates mechanistic insights across species, emphasizing opportunities to translate fundamental discoveries into sustainable agricultural innovations, from breeding nutrient-rich cultivars to optimizing postharvest technologies for global food security.