An object of the present invention is to provide a method for producing aflavone whereina malonyl group is added to a glucose at position 7 using a polynucleotideencoding a proteinhaving activity that transfers a malonyl group to position 6 of the glucose atposition 7 of flavone7-glucoside, and create a plant variety having a modified flower color, andpreferably a flowercolor that is bluer than that of existing varieties, by containing as a co-pigment a flavone whereina malonyl group has been added to the glucose at position 7.A polynucleotide is used that is selected from the group consisting of, forexample: (a) apolynucleotide consisting of the base sequence of SEQ ID NO: 1； (b) apolynucleotide thathybridizes under stringent conditions with a polynucleotide consisting of thebase sequencecomplementary to the base sequence of SEQ ID NO: 1 and encodes a proteinhaving activity thattransfers a malonyl group to position 6 of the glucose at position 7 offlavone 7-glucoside； (c) apolynucleotide that encodes a protein consisting of the amino acid sequence ofSEQ ID NO: 2；and, (d) a polynucleotide encoding a protein that consists of an amino acidsequence wherein oneor a few amino acids have been deleted, substituted, inserted and/or added inthe amino acidsequence of SEQ ID NO: 2 and has activity that transfers a malonyl group toposition 6 of theglucose at position 7 of flavone 7-glucoside.
