UDP-glucose-dependent glucosyltransferase catalyzing the C-glucosylation of 2-hydroxyflavanones (2-hydroxynaringenin, 2-hydroxyeriodictyol and 2-hydroxypinocembrin) and phloretin (PubMed:25142187). No activity with flavanones, flavones or flavonols (PubMed:25142187). Exhibits C-glycosylation activity toward 2',4',6'-trihydroxyacetophenone and phloretin using UDP-glucose as sugar donor (PubMed:32699169). Can use UDP-galactose as sugar donor, but catalytic efficiency is 14-fold lower toward UDP-galactose than toward UDP-glucose (PubMed:32699169). a 3'-hydro-2'-hydroxy-beta-oxodihydrochalcone + UDP-alpha-D-glucose = a 3'-(beta-D-glucopyranosyl)-2'-hydroxy-beta-oxodihydrochalcone + H(+) + UDP Optimum pH is 6.5-7.0. Optimum temperature is 45-50 degrees Celsius. Expressed in cotyledons. Not detected in flowers, leaves, roots and hypocotyls. Expressed in germinating seeds and during cotyledon development. Belongs to the UDP-glycosyltransferase family.