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(+) Associates with the oil body membrane. Expressed in pollen grains and pollen tubes. Belongs to the AB hydrolase superfamily. Lipase family.