A model for the ER as an oil “vent” is not too difficult to envision
and this general scheme for triacylglycerol synthesis in the ER
might have been exaggerated during plant evolution and specialized
(with specific subcellular machinery) allowing oil storage in
certain tissue types such as those in oil seeds or oleaginous fruits. In
fact, recent transcriptome profiling of fruit tissues from two related
palm species [42], oil palm that accumulates large amounts of triacylglycerols,
and date palm that accumulates large amounts of
soluble sugars, revealed that there was little-to-no difference in the
abundance of transcripts encoding the ER acyltranferase machinery
(i.e., PDATs or DGATs)