Peptide transporter. Mediates the transport of di- and tripeptides. High affinity transporter with low selectivity. No transport of amino acids. Expressed in cotyledons, hypocotyls, leaves, roots, flowers, pistils and vascular tissue of sepals, anthers, carpels and funiculi. Not detected in seeds. Reduced growth and lower N content when cultivated on dipeptides. No effect on germination. Belongs to the major facilitator superfamily. Proton-dependent oligopeptide transporter (POT/PTR) (TC 2.A.17) family.