Possesses quercetin 3-O-glucosyltransferase activity in vitro. Also active in vitro on benzoates and benzoate derivatives. Involved in stress or defense responses. a flavonol + UDP-alpha-D-glucose = a flavonol 3-O-beta-D-glucoside + H(+) + UDP Expressed in roots and flowers. Induced by pathogen infection, by H(2)O(2) and by salicylic acid. Decreased resistance to avirulent strains of P.syringae. Belongs to the UDP-glycosyltransferase family.