Studies on the Proteinaceous Subcellular Particles in Rice Endosperm: Electron-Microscopy and Isolation

Electron-microscopic examination of rice endosperm revealed the existence of protein-aceous subcellular particles, 1 to 4 µ in diameter and spherical or oval in shape. Isolation of the particles was effected by differential centrifugation in density gradient medium after mechanical or enzymic disintegration of endosperm cells. The isolated particles were predominantly composed of protein, and residual constituents were mainly lipid and carbohydrate. Their shape and behaviors were similar to those found in the endosperm. These facts show that the subcellular particles concerned are “protein bodies” There seemed to be several kinds of protein bodies different with respect to their protein and lipid contents.