Required for shoot apical meristem (SAM) formation during embryogenesis. Negatively regulates ASYMMETRIC LEAVES1 (AS1) and ASYMMETRIC LEAVES2 (AS2 or LBD6). Probably binds to the DNA sequence 5'-TGAC-3'. Binds to RNA (By similarity). Forms homodimers (PubMed:17965274). May form heterodimeric complexes with TALE/BELL proteins BEL1, BLH2, BLH3, BLH8/PNF, BLH9/PNY and ATH1. Interacts with CCT8 (PubMed:21868675). Binds to MBP2C; this interaction reduces RNA binding capacity (PubMed:17965274). Interacts with FTIP3 and FTIP4 (PubMed:29742441). Association with TALE/BELL proteins is necessary for nuclear location (PubMed:16513846). Dynamic localization via a plasmodesmata-mediated cell-to-cell transport. This shuttle is repressed by MBP2C binding in cytosolic punctae, at microtubules (PubMed:17965274). Subcellular localization and trafficking is regulated by FTIP3 and FTIP4, which promote endosome localization (PubMed:29742441). Expressed in all four types of shoot apical meristems (SAM) i.e. in vegetative, axillary, inflorescence and floral. First expressed in early to mid-globular-stage embryos. In late globular stage, detected as a stripe running medially across the top of the embryo. In heart stage embryo, expression is restricted to a notch between the cotyledons, in both hypodermal and protoderm cells. In the bending-cotyledon stage, localized in the SAM, but disappears from the boundary region of cotyledon margins (BCM). In seedlings and adult plants found in all shoot apical meristems. In the inflorescence meristem, expression disappears as floral buds are initiated and reappears in the later floral meristem where it is found in the central portion of the developing gyneocium. Also detected in the L1 layer of embryo. Belongs to the TALE/KNOX homeobox family.