Flavonol 7-O-rhamnosyltransferase that catalyzes the transfer of rhamnose from UDP-rhamnose to the 7-OH position of 3-O-glycosylated flavonols, such as kaempferol 3-O-rhamnoside, kaempferol 3-O-glucoside, quercetin 3-O-glucoside, quercetin 3-O-galactoside, quercetin 3-O-rhamnoside and isorhamnetin 3-O-glucoside. Is able to glycosylate the flavonols quercetin and kaempferol to yield quercetin 7-O-rhamnoside and kaempferol 7-O-rhamnoside. Shows a strict specificity for UDP-rhamnose as sugar donor. Does not act on 3-O-glycosylated anthocyanins. The accumulation of kaempferol 3-O-rhamnoside-7-O-rhamnoside inhibits basipetal auxin transport, which influences auxin distribution and plant organ development.

> 85% as determined by SDS-PAGE.