Transcriptional repressor that regulates multiple aspects of plant growth and development through the regulation of BEL1-LIKE (BLH) and KNOX TALE (KNAT) homeodomain transcription factors. Controls the subcellular localization of the homeodomain protein BLH1. Plays a role in the regulation of cell elongation by controlling the expression of GA20OX1, a gene that encodes a key enzyme in gibberellin biosynthesis. May play a role in double-stranded DNA repair through the DNA non-homologous end joining (NHEJ) pathway along with KU70 and KU80 protein complex. Possesses DNA-binding activity towards double-stranded and single-stranded DNA in vitro. Interacts with ATH1, BLH1, BLH2, BLH3, BLH4, BLH5, BLH10, KNAT1, KNAT3, KNAT4, KNAT5, KNAT7 and KU70. Expressed in roots, xylem of stems, flower buds and siliques. By the DNA-damaging agents methyl methanesulfonate (MMS) and menadione. No visible phenotype under normal growth conditions, but mutant plants are hypersensitive to the DNA-damaging agents methyl methanesulfonate (MMS) and menadione. Plants over-expressing OFP1 show stunted growth with general delayed development and shortening and thickening of all aerial parts. Leaves are irregularly heart-shaped and lobed and display curved surfaces. Anthers are short with a thick filament and style and stigma protruded from the flower. Siliques are short and uneven and produce few seeds (PubMed:15781858 and PubMed:21886836).