Endosperm of cereal

Endosperm is a prominent tissue persists in the a mature cell of cereal. Its functions as a storage tissue in which the majority of starch and seed storage proteins are synthesized.

Cereal proteins are largely concentrated in the starch-rich endosperm, while the remainder is inside the bran and germ.

The most important grain proteins in endosperm are prolamin composed of the glutenin and gliadin fractions, and are regarded as storage proteins.

Lipid, vitamin and mineral contents in endosperm is lower. However, nutritional and functional significance of the endosperm is evident because of its largest proportion in a cereal grain by mass.

The endosperm consists of two distinct tissues, the starchy endosperm and the aleurone. They have different functions during grain development, dormancy and after germination. 

Cell of the starchy endosperm are non-living while the thick walled with dense contents, nucleated, aleurone cells are living at grain maturity and are packed with protein bodies and lipid droplets.The aleurone layer in barley is generally three cells deep, but in wheat, maize and rice it is only a single cell in depth.

Unlike the tissue they surrounded, aleurone cells contain no starch but they have a high protein content and they are rich in lipid. Aleurone layer and endosperm cells have a common lineage and thus are related although they differ morphologically.

Aleurone are extremely important in both grain development, during which they divide to produce starchy endosperm cells, and germination. An understanding of the regulation of storage proteins, starch and lipid synthesis in the endosperm is great importance for the engineering of improve grain quality for specific end-uses.
Endosperm of cereal