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), phosphatidic acid (PA), phosphatidylserine (PS) and phosphatidylinositol (PI). Favors the release of fatty acid at the sn-1 position for PC or PE and the sn-2 position for PG, PA, PS and PI. Negatively affects disease resistance to the necrotic fungal pathogen Botrytis cinerea and the avirulent bacteria Pseudomonas syringae by promoting cell death and reducing the efficiency of the hypersensitive response, respectively. However, PLP2 contributes to resistance to cucumber mosaic virus (CMV), an obligate parasite inducing hypersensitive response. May negatively regulate oxylipin production, possibly via participating in membrane repair that includes removal of oxidatively modified lipids. Expressed specifically in roots. By infection with the fungal pathogens B.cinerea and A.brassicicola, and avirulent and virulent strains of P.syringae pv tomato DC3000 (at protein level). Induced by ethylene and copper. 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 leaves of mutant plants contain decreased levels of lysophosphatidylcholine (LPC) and lysophosphatidylethanolamine(LPE), but increased levels of free linolenic acid, jasmonic acid and methyl jasmonate, as well as the oxylipin-biosynthetic intermediates 13-hydroperoxylinolenic acid and 12-oxophytodienoic acid. Belongs to the patatin family. Truncated N-terminus.