Aleurone layer

Aleurone Layer

The aleurone layer is a specialized tissue found in most plant seeds. It is the outermost layer of the endosperm, the tissue that surrounds the embryo and provides nutrition in the form of starch, though it can also contain proteins and lipids.

Function

The primary function of the aleurone layer is to facilitate the digestion of stored food reserves during germination. When a seed begins to germinate, the aleurone layer releases enzymes that break down the endosperm's starch and proteins into simpler molecules that the growing embryo can use.

Structure

The aleurone layer is typically single-layered, although in some species it can be multi-layered. It is composed of large, thick-walled cells that are rich in proteins. The cell walls of the aleurone layer are often impregnated with phytic acid and minerals.

Role in Human Nutrition

In many cereal grains, the aleurone layer is a significant source of nutrients. For example, in wheat and rice, the aleurone layer contains high levels of vitamin B and dietary fiber. However, during the milling process, the aleurone layer is often removed along with the bran, resulting in a loss of these nutrients.

See Also

• Endosperm
• Germination
• Seed