Transcriptional regulation and functional research of sucrose synthase in plant development.

This paper reviews the pivotal role of sucrose synthase (SUS) in plant development and stress responses, highlights its upstream transcriptional regulation, as well as its involvement in cellulose synthesis and starch synthesis, facilitating a deeper insight into its biological functions and molecular mechanisms. Sucrose synthase (SUS) is a key enzyme in plant sucrose metabolism, catalyzing the reversible conversion of sucrose into fructose and uridine diphosphate glucose to maintain sucrose balance between source and sink. SUS, encoded by a multigene family, is categorized into SUS I, SUS II, and SUS III types, displaying largely tissue-specific expression and differential functions among family members. It plays a regulatory role in root development, flower and fruit development, seed development, as well as fiber development and elongation. In addition, it is involved in starch biosynthesis, cellulose synthesis, sugar metabolism, and response to various abiotic stresses, including drought, heat, cold, salt, hypoxic and weak light. Here, we summarize structure characteristics, evolutionary relationships, classification, expression profiles, upstream transcriptional regulation of SUS genes, and particularly its multiple roles in plant development and stress responses, aiming to lay a theoretical foundation for further research on the biological functions and molecular regulatory mechanisms of SUS.