Regulation of sugar metabolism in fruits

The sugar content, species, and proportion play a vital role in determining the fruit flavor, and their regulation is influenced by various factors, including transcription factors (TFs), epigenetic modifications, phytohormones, and environmental conditions. Numerous TFs have been identified as key regulators of sugar metabolism through their control over the expression of genes involved in sugar biosynthesis and transport. Epigenetic modifications, such as DNA methylation, histone modifications, and non-coding RNAs, also play a significant role in regulating sugar metabolism by maintaining genome architecture and modulating gene expression. Moreover, the metabolic process of sugar is significantly influenced by phytohormones, including abscisic acid, gibberellin, auxin, ethylene, salicylic acid, jasmonate, brassinosteroid, strigolactone, and melatonin. Additionally, environmental factors such as light, temperature, water, and mineral elements can exert an impact on sugar metabolism. This review offers a comprehensive examination of the regulatory mechanisms governing sugar metabolism, encompassing transcriptional, epigenetic, and phytohormonal perspectives, as well as other factors that affect various aspects of fruit metabolism. The innovative aspect of this review lies in its comprehensive and integrated analysis of the multiple factors that contribute to the regulation of sugar metabolism in fruits. Understanding these regulatory mechanisms is of great significance for improving fruit quality and flavor.