Involved in the release of fatty acids from the oil body in germinating seedlings (PubMed:16473965, PubMed:19136267, PubMed:27466365). Can hydrolyze triacylglycerols and diacylglycerols but not monoacylglycerols, phospholipids, galactolipids or cholesterol esters (PubMed:16473965, PubMed:19136267). SDP1 lipase activity is required to limit triacylglycerol accumulation in roots, leaves and stems, which are vegetative tissues (PubMed:23686420). Functions synergistically with PDAT1 in regulating fatty acid flow from membrane lipid synthesis toward peroxisomal beta-oxidation through a transient triacylglycerol pool (PubMed:25293755). a triacylglycerol + H2O = a diacylglycerol + a fatty acid + H(+) 1,2,3-tri-(9Z-octadecenoyl)-glycerol + H2O = (9Z)-octadecenoate + di-(9Z)-octadecenoylglycerol + H(+) Inhibited by diethyl-p-nitrophenyl phosphate, diisopropyl fluorophosphate and [E]-6-[bromoethylene]-3-[1-naphthalenyl]-2H-tetrahydropyran-2-one. Broad optimum pH around 8.0. Associates with the oil body membrane (PubMed:16473965). Migrates from peroxisomes to the oil body surface through peroxisomal tubulation (PubMed:25775518). Expressed in roots, leaves and stems. Transcript levels increase at the beginning of seed maturation and remain high until seed desiccation is completed. High levels early in seed imbibition, but decline as the seed germinates. Not impaired in germination, but much slower rate of postgerminative growth. Transcript levels do not correlate positively with enzyme activity, suggesting a post-transcriptional regulation. Belongs to the PLPL family. Truncated N-terminus.