Fig. 1.

Extracellular PLD activity depends on secretion rather than hyphal rupture and varies depending on the nutritional value of the growth media. A, Metabolically labeled phospholipids were isolated and vesicles generated as described before (44). Vesicles were incubated in the presence of 2% propanol with buffer only (C) or with extracellular medium derived from 10 days culture with indicated media, with overnight incubated renewed medium or overnight incubated with V8 medium. Lipids were visualized by phosphoimaging after extraction and separation by ethyl acetate TLC (44). The experiment was repeated twice with similar results. B, P. infestans mycelial plugs were metabolically labeled with ³²P and left untreated, or snapfrozen and thawed (FT) for 15 min in the presence of 2% propanol. Phospholipids were extracted, separated by alkaline TLC (7474) and analyzed by phosphoimaging. The origin, phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidic acid (PA), and phosphatidylpropanol (PPro) are indicated. A representative experiment is shown.