Mediates active uptake of hexoses by sugar:proton symport. Can transport glucose, xylose and 3-O-methylglucose. May be involved in the accumulation of monosaccharides required for cell wall synthesis during root development. Highly expressed in roots. Expressed in xylem and sclerenchyma cells of roots. Expressed at low levels in leaves. Belongs to the major facilitator superfamily. Sugar transporter (TC 2.A.1.1) family.