Sucrose-cleaving enzyme that provides UDP-glucose and fructose for various metabolic pathways. an NDP-alpha-D-glucose + D-fructose = a ribonucleoside 5'-diphosphate + H(+) + sucrose Optimum pH is 6.0-7.0 for degradative reaction (PubMed:22184213, PubMed:17257168). Optimum pH is 7.0 for synthetic reaction (PubMed:22184213). Optimum pH is 9.0-9.5 for synthetic reaction (PubMed:17257168). Detected in the whole plant with highest expression in young rosette leaves and roots. By anaerobic stress. By hypoxia in the roots (at protein level). Up-regulated by NUC/IDD8. No visible phenotype. Belongs to the glycosyltransferase 1 family. Plant sucrose synthase subfamily. Truncated N-terminus.