Acts as a vacuolar hexose transporter (PubMed:25988582). Regulates fructose (Fru) homeostasis in leaves and roots by exporting/importing Fru through the tonoplast regarding metabolic demand (PubMed:23583552, PubMed:24381066). Vmax with fructose as substrate is 479.8 pmol/min/ul of vacuole. Forms homooligomers and heterooligomers with SWEET1, SWEET2, SWEET3, SWEET4, SWEET6, SWEET7, SWEET8, SWEET9, SWEET11, SWEET12, SWEET13, SWEET15 and SWEET16. Expressed in leaves at low levels, mostly in xylem and parenchyma (PubMed:23583552, PubMed:24381066). Highly expressed in the cortex of roots, predominantly in tips and mature regions, especially in tonoplasts. Accumulates also in cotyledons, stems, flowers, and siliques (PubMed:24381066). Slightly induced by the fungal pathogen B.cinerea. Accumulates in response to nitrogen deficiency and cold stress. Expression follows a diurnal rhythm with a peak in the middle of the day (PubMed:23583552). Induced in roots by fructose (Fru) and darkness, thus triggering accumulation and release of vacuolar Fru, respectively (PubMed:24381066). High fructose levels in leaves, especially in vacuoles, due to impaired vacuolar fructose export (PubMed:23583552). Increased root sensitivity to high levels of fructose (PubMed:24381066). Belongs to the SWEET sugar transporter family.