Groucho/Tup1 family co-repressors in plant development.

Transcription repression is emerging as a key regulatory mechanism underlying cell fate specification and body patterning in both animals and plants. In animals and fungi, the Groucho (Gro)/Tup1 family co-repressors generate the repressed chromatin state in genetic loci that control major developmental decisions ranging from dorsal-ventral patterning to eye development. In higher plants, information about the Gro/Tup1 co-repressors is beginning to emerge. Several recent publications have revealed both conserved and unique structural and mechanistic features of plant Gro/Tup1 co-repressors, including LEUNIG (LUG), TOPLESS (TPL) and WUSCHEL-INTERACTING PROTEINS (WSIPs). These co-repressors regulate key developmental processes in floral organ identity specification, embryo apical-basal fate determination, and stem cell maintenance at the shoot apex.