Inositol phosphate kinase with a broad substrate specificity. Phosphorylates inositol 1,4,5-trisphosphate (Ins(1,4,5)P3), inositol 1,4,5,6-tetrakisphosphate (Ins(1,4,5,6)P4), inositol 1,3,4,5-tetrakisphosphate (Ins(1,3,4,5)P4), inositol 1,3,4,6-tetrakisphosphate (Ins(1,3,4,6)P4) and inositol 1,2,3,4,6-pentakisphosphate (Ins(1,2,3,4,6)P5) but not inositol 1,4-bisphosphate (Ins(1,4)P2), inositol 1,3,4-trisphosphate (Ins(1,3,4)P3), inositol 1,2,6-trisphosphate (Ins(1,2,6)P3), inositol 3,4,5,6-tetrakisphosphate (Ins(3,4,5,6)P4), inositol 1,3,4,5,6-pentakisphosphate (Ins(1,3,4,5,6)P5), inositol 1,2,4,5,6-pentakisphosphate (Ins(1,2,4,5,6)P5) or inositol hexakisphosphate (InsP6). Regulates pollen and root development probably through the regulation of InsP3-mediated calcium accumulation. 1D-myo-inositol 1,4,5-trisphosphate + 2 ATP = 1D-myo-inositol 1,3,4,5,6-pentakisphosphate + 2 ADP + 2 H(+) 1D-myo-inositol 1,3,4,6-tetrakisphosphate + ATP = 1D-myo-inositol 1,3,4,5,6-pentakisphosphate + ADP + H(+) Detected in leaves, stems, roots, siliques and flowers. Highly expressed in root tissues, anthers, the stigma, pollen grains and growing pollen tubes. Expression persisted in the stigmatic tissue after fertilization and in siliques during seed maturation. Not induced by auxin. Phosphorylated. Does not bind calmodulin. Belongs to the inositol phosphokinase (IPK) family.