Lipid-binding oleosin pollen coat protein required to mediate pollen recognition by stigma cells and subsequent pollen hydration (PubMed:10655594, PubMed:20033440, PubMed:26305561). Involved in anther tapetum development, especially for the physiology of tapetosomes (PubMed:26305561). Also implicated in the formation of pollen coat (PubMed:26305561). Surface of oil bodies (By similarity). Oleosins exist at a monolayer lipid/water interface (By similarity). Associated with discrete organelles (e.g. granules of 1-5 um in diameter) within the anther tapetum called tapetosomes and with a network of structures previously described as fibrils or 'strings of beads' (PubMed:26305561, PubMed:23602096). Flower specific, especially in anther tapetum, pollen (at protein level) and flowers florets. Mostly expressed in anthers at the later stage of flower development until tapetum degeneration (PubMed:8220457, PubMed:23602096). In flowers, present in the anther tapetum early in anther development and later in the pollen coat (PubMed:11929861, PubMed:26305561). Upon tapetum degeneration, associated with tapetosomal debris 'in transit' to the pollen cell wall in the anther locule (PubMed:26305561, PubMed:23602096). Translocates from the pollen coat at exine cavities to the site of contact between the pollen grain and a papillar cell, called 'foot', 10 minutes after pollen landing; the pollen tube elongation initiates later (about 20 minutes after pollination) at the foot (PubMed:26305561). Proteolytically cleaved following anther tapetal breakdown. Delayed pollen hydration and impaired competitive ability due to a failure to interact with the stigma (PubMed:10655594, PubMed:20033440). Abnormal anther tapetum development (PubMed:26305561). Belongs to the oleosin family.