Microsomal preparations from the developing cotyledons of safflower (Carthamus tinctorius) catalyse the acylation of sn-glycerol 3-phosphate in the presence of acyl-CoA. Under these conditions the radioactive glycerol in sn-glycerol 3-phosphate accumulates in phosphatidic acid, phosphatidylcholine, diacyl- and tri-acylglycerol. The incorporation of glycerol into phosphatidylcholine is via diacylglycerol and probably involves a cholinephosphotransferase. The results show that the glycerol moiety and the acyl components in phosphatidylcholine exchange with the diacylglycerol during the biosynthesis of diacylglycerol from phosphatidic acid. The continuous reversible transfer of diacylglycerol with phosphatidylcholine, which operates during active triacylglycerol synthesis, will control in part the polyunsaturated-fatty-acid quality of the final seed oil.
Polyunsaturated fatty acid‐containing phosphatidic acid interacts with synaptojanin‐1 and enhances its phosphoinositide D‐4‐phosphatase activity
