A method for altering the ratio of total daidzein to total genistein in isoflavonoid-producing plants by using a C1 myb transcription factor and an R-type myc transcription factor is described. Also described are plant comprising these transcription factors in their genome as well as isoflavonoid-containing products made from seeds of these plants. Such products have an increased ratio of total daidzein to total genistein when compared to the total daidzein to total genistein ratio of a control.