Inhibitor of E2F-dependent regulation of gene expression. Binds specifically the E2 recognition site as a monomer without interacting with DP proteins. May be up-regulating E2FA and down-regulating repressors of cell cycle progression. Promotes cell proliferation and represses cell elongation. Regulated by proteolysis via a ubiquitin-proteasome pathway. Monomer. No interactions with DPA or E2FA. Preferentially expressed in proliferating tissues. Highly expressed in young stalk and young flowers. Lower expression in young leaves and mature flowers. Detected in cotyledonary vascular tissues, the shoot apical meristem, the base of trichomes, the fully developed stomata, the central root cylinder and in the columella of lateral roots but not in the primary root tips or in the leaf epidermal cells. Expressed in a cell cycle-dependent manner. Not detected at the G1/S transition, but increases during the progression into S phase and peaks after the passage into G2. Down-regulated posttranscroptionally by auxin. The two DNA binding domains are required for binding to the E2 site. Increased root length and smaller cotyledons. Reduced root meristematic zone but longer cells in the differentiation zone. Belongs to the E2F/DP family.