Mostly expressed in aerial organs, particularly in expanding leaves, stems, flowers, and siliques. In young seedlings, detected in the hypocotyl, cotyledons and rosette leaves,mostly in expanding leaves. At flowering time, expressed in stems, cauline leaves, sepals, and, in closed flowers only, in anthers. Later present in pedicels of developing siliques, nectaries, and along the length of maturing siliques. Belongs to the plant proline-rich protein superfamily.