Fatty acid composition of lipids from the vacuoles of higher plants

Fatty acid composition of vacuolar membrane lipids from plant storage tissu es was studied, and possible pathways of the biosynthesis of these acids we re considered. A high level of unsaturated fatty acids (up to 77% of the to tal) was characteristic of these membrane lipids. Linoleic acid predominate d in the vacuolar lipids of carrot and red beet (54.2 and 44.2%, respective ly), and a-linolenic acid was most abundant in the lipids of turnip and rad ish (39.7 and 33.2%, respectively). Palmitic acid was the predominant satur ated acid, comprising 20.0-24.0% of total fatty acids, in the vacuolar lipi ds of radish, carrot, and red beet. Petroselinic acid (4.4-5.4%) was detect ed in the vacuolar lipids of radish, carrot, and turnip. Fluidity, elastici ty, and mobility of the lipid bilayer, as well as the chilling tolerance of vacuolar membranes of higher plants, are suggested to be caused by a high content of polyunsaturated fatty acids.