Besides the Kennedy pathway,triacylglycerol (TAG),the most important stock for microalgae-based biodiesel production,can be synthesized by phospholipid: diacylglycerolacyltransferase (PDAT) by transferring an acyl group from phospholipids (PLs) to diacylglycerol (DAG).This study presents a novel gene coding for PDAT from the green microalga MyrmeciaincisaReisig1 H4301 (designated as MiPDAT) in that MiPDAT proves to be localized on plasma membrane (PM) via agroinfiltration of tobacco leaves with a green fluorescent protein-fused construct.MiPDAT is furthered verified to synthesize TAG in function by complementary experiments in a mutant yeast strain H1246 by using the membrane lipid phosphatidylcholine (PC) that is inferred from the feeding experiments with various fatty acids as substrates.The gradually increased transcription levels of MiPDAT in M.incisa during the cultivation of nitrogen starvation is proposed to be responsible for the decrease and increase of PC and TAG levels,respectively,as detected by liquid chromatography-mass spectrometry after 4 d nitrogen starvation.In addition,how MiPDAT in this microalga uses PC to yield TAG is discussed.Accordingly,it is concluded that this PM-located PDAT contributes to the conversion of membrane lipids into TAG in M.incisa during the nitrogen starvation stress.