Functions as phosphatidylcholine:diacylglycerol cholinephosphotransferase that catalyzes the transfer of the phosphocholine headgroup from phosphatidylcholine (PC) to diacylglycerol, a major reaction for the transfer of 18:1 into phosphatidylcholine for desaturation and also for the reverse transfer of 18:2 and 18:3 into the triacylglycerols synthesis pathway. 1,2-di-(9Z-octadecenoyl)-sn-glycerol + 1,2-ditetradecanoyl-sn-glycero-3-phosphocholine = 1,2-di-(9Z-octadecenoyl)-sn-glycero-3-phosphocholine + 1,2-ditetradecanoyl-sn-glycerol Optimum pH is 6.5-7 at 23 degrees Celsius. Reduction of 18:2 and 18:3 triacylglycerols (TAG) accumulation in seeds by 40 percent. Belongs to the phosphatidylcholine:diacylglycerol cholinephosphotransferase family. Truncated N-terminus.