The production of the second messenger molecules diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) is mediated by activated phosphatidylinositol-specific phospholipase C enzymes. At physiological calcium concentration, the preferred substrate is phosphatidylinositol 4,5-bisphosphate versus phosphatidylinositol. a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-4,5-bisphosphate) + H2O = 1D-myo-inositol 1,4,5-trisphosphate + a 1,2-diacyl-sn-glycerol + H(+) A number of isoforms are produced. According to EST sequences. Expressed in roots, shoots, leaves and flowers. Not induced by environmental stresses such as dehydration, salinity and low temperature. Amino acids 23-36 of the EF-hand-like domain are necessary catalysis but not for binding to lipid vesicles. Phosphorylation level varies significantly during early response to bacterial elicitor. Truncated C-terminus.