High-affinity transporter for external inorganic phosphate. Mainly expressed in shoots, First throughout cotyledons and hypocotyls and later restricted to vascular tissues, mostly in phloem. Present in senescing leaves. Also expressed in floral buds and sepals. Slightly induced in roots during phosphate starvation. Although related to the sugar transporter family, it does not transport sugars. Belongs to the major facilitator superfamily. phosphate:H(+) symporter (TC 2.A.1.9) family.