Extracellular signal peptide that regulates cell fate. Mostly expressed in roots, stems and apex, and, to a lower extent, in seedlings, leaves, flowers, siliques and pollen. The O-glycosylation (arabinosylation) of the hydroxyproline Pro-78 enhances binding affinity of the CLE3p peptide for its receptor. Belongs to the CLV3/ESR signal peptide family. Extended C-terminus.