Hydrolyzes glycerol-phospholipids at the terminal phosphodiesteric bond to generate phosphatidic acids (PA). Phosphatidylcholine-selective (PubMed:11891260). Regulates root-hair morphogenesis (PubMed:12775839). Contributes to the supply of inorganic phosphorus for cell metabolism and diacylglycerol moieties for galactolipid synthesis in phosphorus-starved roots (PubMed:16891548). Involved in root elongation during phosphate limitation (PubMed:16384909). a 1,2-diacyl-sn-glycero-3-phosphocholine + H2O = a 1,2-diacyl-sn-glycero-3-phosphate + choline + H(+) Does not require Ca(2+) or any other cation for activity. Calcium-independent and PIP2-dependent. Optimum pH is 7.0. Expressed in inflorescences, flowers, siliques, stems, leaves, and roots. Highest expression in roots. Transcriptionally regulated by GL2 (PubMed:12775839). Up-regulated by phosphate limitation (PubMed:16384909). No visible phenotype when grown under normal conditions (PubMed:16384909). No effect on root hair patterning or root hair growth (PubMed:16384909). No effect on the concentration of phospholipids and galactolipids in phosphorus-starved roots (PubMed:16891548). Pldzeta1 and pldzeta2 double mutants show a smaller decrease in phosphatidylcholine and a smaller increase in digalactosyldiacylglycerol in phosphorus-starved roots (PubMed:16891548). Pldzeta1 and pldzeta2 double mutants show reduced primary root elongation and increased lateral root elongation under low-phosphate conditions (PubMed:16384909). Belongs to the phospholipase D family. PXPH-PLD subfamily.