PROBLEM TO BE SOLVED: To provide a gene encoding a new protein having an activity of transferring glucose to a sugar moiety at the 3-position of a flavonoid, and a method for using the same. SOLUTION: The gene is derived from, e.g. a morning glory, has a specific amino acid sequence and encodes the protein transferring the glucose to the sugar moiety at the 3-position of anthocyanin. A protein encoded with the gene is provided. A plant in which the gene is transduced produces a flower, or the like, having a color different from that of a natural plant by expression of the gene. COPYRIGHT: (C)2004,JPO