Low-affinity transporter for inorganic phosphate (Pi) (PubMed:18980647). Involved in internal Pi transport from root to shoot (PubMed:18980647, PubMed:20149131). Responsible for most of the PHR2-mediated accumulation of excess shoot Pi under abundant Pi conditions, but not for PHO2-mediated accumulation of excess shoot Pi (PubMed:20149131). Acts as a H(+):phosphate symporter (PubMed:18980647). Expressed in the root stele and leaf phloem and xylem. Regulated by the transcription factor PHR2 (PubMed:20149131). Up-regulated in roots by phosphate starvation (PubMed:18563580). Down-regulated in roots by high phosphate or colonization by the mycorrhizal fungus G.intraradices (PubMed:12271140). 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.