Abstract
Endosperm tissue of mature kernels of rye (Secale cereale L.) cv. Dominant was examined by light and transmission electron microscopy. It was found that storage protein in sub-aleurone cells occupies up to 35 per cent of the cell volume and forms a continuous matrix in which starch grains and cytoplasmic remnants are embedded. In the prismatic endosperm, the storage protein is present as a fine network interspersed between the numerous type A and B starch grains. Protein bodies are not found in the prismatic endosperm; only a few, less than 1 μm in diameter, are observed in pockets of disorganized cytoplasm in the sub-aleurone tissue. Thick cell walls and intercellular material may contribute to the high pentosan content of rye endosperm.