UDP-glucose-dependent glucosyltransferase catalyzing the C-glucosylation of 2-hydroxyflavanones (2-hydroxylnaringenin and 2-hydroxypinocembrin) and phloretin (PubMed:28370711). No activity with flavanones, flavones or flavonols (PubMed:28370711). Exhibits C-glucosylation activity toward 2-phenyl-2',4',6'-trihydroxyacetophenone (PubMed:28370711). Can use UDP-xylose as sugar donor, but catalytic efficiency is much lower toward UDP-xylose than toward UDP-glucose (PubMed:28370711). 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 8.0-11.0. Optimum temperature is 45 degrees Celsius. Expressed at low levels in leaves, flowers and immature leaves. Belongs to the UDP-glycosyltransferase family.