Possesses non-specific lipolytic acyl hydrolase (LAH) activity. Catalyzes the hydrolysis of the galactolipids monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), and less efficiently the phoshpolipids phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylserine (PS) and phosphatidylinositol (PI). Hydrolyzes phospholipids at both the sn-1 and sn-2 positions. Involved in basal jasmonic acid production and promotes resistance to the necrotrophic fungal pathogen Botrytis cinerea. A number of isoforms are produced. According to EST sequences. The nitrogen atoms of the two glycine residues in the GGXR motif define the oxyanion hole, and stabilize the oxyanion that forms during the nucleophilic attack by the catalytic serine during substrate cleavage. No visible phenotype under normal growth conditions, but mutant plants have reduced basal level of jasmonic acid and exhibit increased susceptibility to the fungal pathogen Botrytis cinerea. Belongs to the patatin family.