Abstract
Higher plants continuously generate new organs from shoot apical meristem. This developmental process requires to coordinate the undifferentiated and differentiated cell fates and Arabidopsis TCP3 regulates differentiation of cells in leaves. Knockout mutants for CIN-like TCP genes had multiple shoot meristems in seedlings, marginal outgrowth of leaves and ectopic expression of CUP-SHAPED COTYLEDON (CUC) genes. TCP3 directly regulated a specific set of genes for differentiation of leaves, as revealed by analyses of microarray, promoter activities, chromatin immunoprecipitation and transient gene expression. The target genes of TCP3 were involved in the repression of expression of CUC genes, since gain of function of these target genes showed fusion of cotyledons whereas loss of these target genes additively displayed ectopic expression of CUC genes in leaves. Our results suggest that TCP3 integrates activities of the specific set of genes for the repression of expression of CUC genes.
