Newly synthesized acyl-CoAs (shown in green) are exported from the plastid to the endoplasmic reticulem (ER) membrane where they join a larger acyl-CoA pool. A series of reactions adds the fatty acids to a glycerol backbone to form triacylglycerol (TAG). TAG molecules coalesce to form oildroplets that bud out of the ER membrane. Additional reactions integrate the synthesis of TAG with that of phosphatidylcholine (PC), an important membrane lipid. Fatty acids can be further desaturated when they are part of the PC pool.

TAG Biosysthesis Pathway in Soybean
  Note: Some enzymes in red text have a link for further information