May be involved in the translocation of tetra- and pentapeptides across the cellular membrane in an energy-dependent manner. Acts also as a metal transporter that could be a component of the copper transport machinery. Essential for early embryo development. Strong expression in flowers, leaves and roots. Preferentially expressed in the vascular tissues of seedlings and mature plants as well as in pollen and developing embryos. Expressed 2 to 4 hours after fertilization in the embryo sac and subsequently in developing maternal tissues. By the globular stage, expression is observed in the developing endosperm, integument layers, the embryo proper, and the suspensor of the developing embryo. From the heart stage onward, expression observed in the embryo but neither in the suspensor nor in the endosperm and integument tissues. Highly induced by iron, copper and manganese deficiencies. Belongs to the oligopeptide OPT transporter (TC 2.A.67.1) family.