Involved in the translocation of tetra- and pentapeptides across the cellular membrane in an energy-dependent manner. Also involved in transport of glutathione derivatives and metal complexes, and may be involved in stress resistance. Expressed in flowers and roots, and at a low level in leaves and stems. Detected in the cambial zone of the vascular bundles and in the region of lateral root initiation. Low expression in the vascular network of the petals and high in the stamen filaments and the gynoecium. In young embryos, transient expression in the procambium and, at later stage, expression over the whole surface of the embryo and in the inner tegument, in the area adjacent to the micropyle. Induced by primisulfuron and abscisic acid, and weakly by 2,4-dichlorophenoxyacetic acid (2,4-D). Not induced by salicylic acid, hydrogen peroxide, reduced and oxidized glutathione or cadmium. Belongs to the oligopeptide OPT transporter (TC 2.A.67.1) family.