The present invention relates to a new promoter of the expression of genes in plants. More specifically, the invention relates to regulatory sequences of polynucleotides that are isolated from soy plants and can initiate and activate polynucleotide transcription, and to the use of these regulatory sequences to modify the transcription of endogenous and/or heterologous polynucleotides and to produce polypeptides. The invention further describes DNA constructs that contain the promoter of the gene of the supposed flavonol-sulfotransferase protein in soy plants, which promoter is functionally linked to a heterologous and/or endogenous gene. Moreover, the invention relates to the use of these constructs in the form of expression cassettes, expression vectors, recombinant vectors and in plants, plant cells or transgenic protoplasts. The invention also describes a method using such constructs that contain the promoter of the gene of the putative flavonol-sulfotransferase protein of soy plants for the production of transgenic plants, plant cells or protoplasts.