Question

The aleurone layer helps in
A. Storage of food in Endosperm
B. Protection of Embryo
C. Utilization of stored food
D. All of the above

Answer 1

Hint: The endosperm of monocotyledonous endospermic seed is surrounded by a special thick layer, called the aleurone layer. It is a one- cell layer.
It performs the function of nourishing the embryo enclosed in the seed. It is a coat rich in protein and formed by the outermost layer of endospermic cells. It actively secretes some enzymes which help in the process of seed germination.

Complete answer:
The aleurone layer performs a variety of functions that help to maintain the proper development of the seed. One example of this is maintaining a low pH in the apoplast. Another is that the aleurone layer releases organic and phosphoric acids in cereals that keep the pH of the endosperm between a pH of 3.5 and 4. In barley, it releases nitrite into the starchy endosperm and apoplast under anaerobic conditions. In addition, a certain class of hemoglobins is present in the aleurone tissue in barley and rice seeds.

During seed germination, the plant embryo secretes the hormone gibberellin which activates the aleurone cells to release α-amylase. It takes part in the hydrolysis of starch, proteases, and storage proteins into the endosperm. The breakdown of the starchy endosperm takes place and supplies sugars to drive the growth of roots and the acrospire. The most important and sole function of the aleurone layer is the release of amylase. This is inhibited by the plant hormone abscisic acid, which keeps the seed dormant. After completing this function, the aleurone cells in the developing seed undergo apoptosis.

Hence, the correct answer is option (C).

Note: Aleurone is a protein found in protein granules of maturing seeds and tubers. The term also depicts one of the two major cell types of the endosperm. The aleurone layer is present in the endosperm. It is the outermost layer, followed by the inner starchy endosperm.