Peptide transporter. Mediates the transport of di- and tripeptides. High affinity, low capacity transporter. Can also transport histidine. Inhibited by leucyl-ethionine. Highly expressed in young leaves, roots and germinating seeds, intermediately in stems, flowers and mature leaves and at low level in siliques. Belongs to the major facilitator superfamily. Proton-dependent oligopeptide transporter (POT/PTR) (TC 2.A.17) family.