The Structure of Mature Rye Endosperm

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.