diphosphate + H2O = H(+) + 2 phosphate Inhibited by NaF. Optimum pH is 7.5. Activity is extremely low below pH 6.5. Activity decreases slightly at more basic pHs, activity at pH 9.0 was only 10% less than that found at pH 7.5. Expressed in all tissues tested. Highest expression in flowers, leaves and roots. Lower levels of expression in siliques, stems, ovary, stigma and pollen. Expressed throughout plant development, with a lower expression in young plantes and a maximum during flowering. By glucose, frustose or sucrose at 300 mM, but not at 100 mM. Belongs to the PPase family.