Provided is a polynucleotide for encoding a protein that exhibits activity for transferring a sugar to a hydroxyl group at position 7 of a flavone, particularly flavone 4-glucoside. A polynucleotide selected from the group consisting of: (a) polynucleotides comprising a base sequence of SEQ ID NO.: 1 or SEQ ID NO.: 5 (b) polynucleotides that hybridize, under stringent conditions, with polynucleotides comprising a base sequence complementary to a base sequence of SEQ ID NO.: 1 or SEQ ID NO.: 5, wherein the polynucleotides encode a protein that exhibits activity for transferring a sugar to a hydroxyl group at position 7 of a flavone (c) polynucleotides for encoding proteins comprising an amino acid sequence of SEQ ID NO.: 2 or SEQ ID NO.: 6 (d) polynucleotides for encoding proteins comprising an amino acid sequence in which one or more amino acids have been deleted, substituted, inserted, and/or added in an amino acid sequence of SEQ ID NO.: 2 or SEQ ID NO.: 6, the polynucleotides exhibiting activity for transferring a sugar to a hydroxyl group at position 7 of a flavone and the like.
