Hydrolyzes glycerol-phospholipids at the terminal phosphodiesteric bond to generate phosphatidic acids (PA). Phosphatidylcholine-selective (PubMed:11891260). Regulates vesicle trafficking and auxin responses (PubMed:17259265). Required for the normal cycling of PIN-2 containing vesicles (PubMed:17259265). Contributes to the supply of inorganic phosphorus for cell metabolism and diacylglycerol moieties for galactolipid synthesis in phosphorus-starved roots (PubMed:16891548, PubMed:16617110). 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. Expressed in seedlings, roots, leaves, stems and flowers (PubMed:17259265, PubMed:16384909). Highest expression in roots (PubMed:16384909). Detected only in the meristematic regions up to 4 days after germination and then at later stages in all tissues (PubMed:16617110). Up-regulated by auxin (PubMed:17259265). Up-regulated by phosphate limitation (PubMed:16384909, PubMed:16617110). No visible phenotype when grown under normal conditions (PubMed:16384909). Shorter roots less sensitive to exogenous auxin (PubMed:17259265). Reduced gravitropism (PubMed:17259265). No effect on root hair patterning or root hair growth (PubMed:16384909). Defective in the hydrolysis of phospholipids, reduced capacity to accumulate galactolipids and premature change in root architecture in response to phosphate starvation (PubMed:16617110). Decreased accumulation of phosphatidic acid in roots under phosphate-limited conditions (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.