In higher plants, the primary seed storage reserve is triacylglycerol rather than carbohydrates. Thus, triacylglycerol degradation is an important pathway from which plants obtain energy for growth. First, triacylglycerol lipase, an enzyme localized to the oil body (storage vacuole) membrane, catalyzes the conversion of a triglyceride into a 1,2-diglyceride. Second, the predicted enzyme diglyceride lipase (coloured orange in the image) is theorized to catalyze the conversion of a 1,2-diglyceride iinto a 2-acylglycerol. Third, a 2-acylglycerol is spontaneously converted into a 1-monoglyceride. Fourth, acylhydrolase catalyzes the conversion of a 1-monoglyceride into glycerol. Fifth, glycerol kinase catalyzes the conversion of glycerol into glycerol 3-phosphate. Sixth, glycerol-3-phosphate dehydrogenase (coloured dark green in the image), localized to the mitochondrial inner membrane, catalyzes the conversion of glycerol 3-phosphate into glycerone phosphate.

Triacylglycerol Degradation References