Proteoglycan that seems to be implicated in diverse developmental roles such as differentiation, cell-cell recognition, embryogenesis and programmed cell death (By similarity). Plays an important role during the formation of the nexine layer of the pollen wall (PubMed:25336567). Expressed in the anthers. Initially detected in the tapetum and microsporocytes during meiosis. Highest expression during the tetrad stage. After microspores were released from tetrad, slightly detected in the tapetum and microspores. Up-regulated by AHL16/TEK. O-glycosylated on the hydroxyproline residues. Belongs to the classical AGP family.