[Glycerolipid biosynthesis in vivo in subcellular fractions of greening wheat sprouts]

The kinetics of [I-14C]acetate incorporation into the glycerolipids of subcellular fractions during the greening of dark-grown wheat sprouts were studied. Up to 80% of the label were incorporated into neutral lipids in the darkness. The main labelled polar lipids were phosphatidic acid, phosphatidyl choline and phosphatidyl glycerol. The synthesis of the latter two compounds was predominantly coupled with the microsomal fraction. Illumination increased the galactolipid formation in the plastids, particularly that of galactosyldiacylglycerol. The role of phosphatidic acid and phosphatidyl choline as possible precursors of the galactolipid biosynthesis in developing plastids is discussed.