Protein Body Degradation in the Starchy Endosperm of Germinating Sorghum

Taylor, J. R. N., Novellie, L. and Liebenberg, N. v. d. W. 1985. Protein body degradation in the starchy endosperm of germinating sorghum.—J. exp. Bot. 36: 1287–1295. Transmission electron micrographs of starchy endosperms of germinating sorghum indicate that the protein bodies are degraded predominantly by progressive hydrolysis of prolamin from their surface. The appearance of holes within partially degraded protein bodies indicates that some internal hydrolysis also takes place. Chemical analyses of protein bodies isolated at different stages during germination showed that their amino acid composition and electrophoretic pattern remained relatively unchanged during hydrolysis. The end result of protein body degradation was that the organelles completely disappeared leaving empty starchy endosperm cells. The protein bodies did not swell prior to or during degradation. This mode of protein body degradation differs from that in germinating dicotyledonous seeds and in the aleurone layer and embryo of cereal seeds but was identical to the mode of prolamin protein body degradation in the starchy endosperm of germinating rice seeds.