Lipid biosynthesis in rice coleoptiles grown in the presence or in the absence of oxygen

Abstract

Rice seeds were germinated either in anaerobic or in aerobic conditions. The lipids of the coleoptiles were labelled by incubation of the seedlings in the presence of [ 14C] acetate for 4 or 24 h. Neutral lipids appeared to be at least twice more radioactive in anaerobic conditions as compared with the labelling in aerobic conditions; the converse was true for phospholipids. The same fatty acids were present in coleoptiles from both types of seedlings. An accumulation of linoleic acid was observed in anaerobic coleoptiles as well as in mitochondria and microsomes prepared from these tissues. However, only the saturated fatty acids of tissues or organelles were labelled from [ 14C] acetate in anaerobic conditions by contrast with the labelling of all fatty acids in air.