Transcription activator. Binds the promoter core sequence 5'-GGNCC-3', especially at sites IIa (5'-GGGCCCAC-3') and IIb (5'-GGTCCCAC-3') (essential for meristematic tissue-specificity expression) of the PCNA gene promoter (PubMed:12000681, PubMed:9338963). Can target the TCP motif 5'-TGGGCC/T-3' (PubMed:24170127). Forms homodimers and heterodimers with PCF2 (PubMed:9338963). Interacts with SPL14/IPA1 (PubMed:24170127). Expressed in seedlings and leaves, mostly in the lower region rich in dividing cells. Truncated N-terminus.