Acid lipase that can hydrolyze a range of triacylglycerols without a clear preference for acyl-chains (PubMed:29178188). Can also cleave 1,2-diacylglycerol, 1,3-diacylglycerol and 1-monoacylglycerol, but not phospatidylcholine, phosphatidylethanolamine, or sterol esters (PubMed:29178188). Required for pollen tube growth (PubMed:29178188). Triacylglycerol hydrolysis by OBL1 may provide acyl groups for the synthesis of membrane lipids in growing pollen tubes (Probable). (9Z)-octadecenoate + 1,2-di-(9Z-octadecenoyl)-glycerol + H(+) = 1,2,3-tri-(9Z-octadecenoyl)-glycerol + H2O 1-(9Z-octadecenoyl)-glycerol + H2O = (9Z)-octadecenoate + glycerol + H(+) Optimum pH is 5.5. Associates with the oil body membrane. Expressed in pollen grains, pollen tubes, developing embryos, developing seeds and germinating seeds. Reduced pollen tube growth. Belongs to the AB hydrolase superfamily. Lipase family. Truncated N-terminus.