Changes in lipid composition of germinating barley embryo

Barley seeds,Hordeum vulgare, var. Kenia, were dissected before and after 5 days of germination, to distinguish between the scutellum, the coleoptile half of the embryo and the coleorhiza half of the embryo. Total lipids were extracted from each fraction and analyzed by thin layer chromatography and gas liquid chromatography. In tissues from the coleoptile and coleorhiza halves of the embryo there was a concurrent disappearance of triglycerides with a marked increase of esterified sterols and esterified sterol glucosides. In the scutellum there was also a change in triglycerides, but the variations in contents of esterified sterols and esterified sterol glucosides were much smaller. Mono- and digalactolipids were virtually absent from embryonic tissue. The amounts of linoleic and linolenic acids in esterified sterol glucosides were increased after 5 days of germination in all the embryonic tissues, especially in the coleoptile half. In sterol esters, linoleic acid comprised nearly half of the total fatty acids, and the desaturation after 5 days of germination was much less pronounced.