Probable transcriptional repressor that regulates multiple aspects of plant growth and development, partly through brassinosteroid (BR) signaling pathway. Acts downstream of the kinase GSK2, a negative regulator of BR signaling. Interacts with GSK2. Phosphorylated OFP8 shuttles from the nucleus to the cytoplasm where it is degraded by the proteasome. Expressed in roots, stems, stem nodes, young leaves, leaf sheaths, lamina joints, young spikelets, inflorescences, stamens and ovaries, embryos and seeds. Induced by 24-epibrassinolide. Phosphorylated on serine and threonine residues by GSK2. Dephosphorylated during response to brassinosteroid. The gain-of-function mutant ofp8 (T-DNA tagging) shows an enhanced lamina joint inclination at the maturation stage. Plants silencing OFP8 have a marked upright leaf phenotype and are insensitive to brassinolide.