Major advances have been made in understanding the role of transcription factors in gene expression in yeast, Drosophila, and man. Transcription factor modification, synergistic events, protein-protein interactions, and chromatin structure have been successfully integrated into transcription factor studies in these organisms. While many putative transcription factors have been isolated from plants, most of them are only poorly characterized. This review summarizes examples where molecular biological techniques have been successfully employed to study plant transcription factors. The functional analysis of transcription factors is described as well as techniques for studying the interactions of transcription factors with other proteins and with DNA.