THE DEVELOPMENT OF PROTEIN BODIES IN THE STORAGE TISSUES OF SEEDS - SUBCELLULAR SEPARATIONS OF HOMOGENATES OF BARLEY, MAIZE, AND WHEAT ENDOSPERMS AND OF PEA COTYLEDONS

Homogenates of the developing endosperms of maize, wheat and barley and of developing cotyledons of peas were separated on sucrose density gradients. Protein bodies were recognized by their content of storage proteins, their density and their appearance under the EM. The distribution of the endoplasmic reticulum was followed by measuring NADH-cytochrome c reductase. Glutamate dehydrogenase, catalase and triose phosphate dehydrogenase.sbd.respectively, marker enzymes for mitochondria, microbodies and plastids.sbd.were also present in the gradients. Differences were between the different species with respect to the association between the endoplasmic reticulum and the storage proteins. There was no evidence for any vacuolar marker enzymes associated with the cereal protein bodies. The protein bodies of wheat and barley appear to be similar to each other but differ from maize in that the latter have much more endoplasmic reticulum associated with them. The protein bodies of peas cosediment with vacuolar marker enzymes.