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 Expressed in parenchymatous tissues, aleurone layers and cell surrounding the vascular tissue in seeds (at protein level). Predominantly expressed in caryopses. Not expressed in seed development before 3 days after pollination (DAP), reaches a peak at 6 DAP and then decreases slightly (at protein level). In the caryopse, expressed specifically from the early to middle storage stage. Belongs to the glycosyltransferase 1 family. Plant sucrose synthase subfamily.