Which is the hormone secreted from the aleurone layer of maize seed during germination?

📌Concept:
The aleurone layer is a specialized layer of cells that surrounds the endosperm of cereal grains like maize, wheat, and barley.
It is located between the endosperm and the seed coat.
The aleurone layer is rich in proteins, lipids, and enzymes and plays an important role in seed germination.
During germination, the aleurone layer synthesizes and secretes hormones that stimulate the breakdown of stored nutrients in the endosperm.
In addition to its role in seed germination, the aleurone layer has also been found to be involved in plant defense against pathogens and pests.

🛑Important Points:
The hormone secreted from the aleurone layer of maize seed during germination is gibberellic acid (GA).
Gibberellic acid (GA) plays a crucial role in maize seed germination.
During seed germination, the embryo produces GA, which stimulates the aleurone layer to synthesize and secrete more GA.
The GA produced by the aleurone layer then diffuses into the endosperm and stimulates the breakdown of stored starch into simple sugars that can be used by the developing embryo.
In addition to promoting starch breakdown, GA also stimulates the synthesis of hydrolytic enzymes like alpha-amylase, proteases and lipases.
These enzymes further help in the breakdown of stored proteins, starches and lipids in the endosperm.
This process releases nutrients that can be used by the growing embryo for energy and growth.
GA also plays a role in promoting the elongation of the embryo axis and the development of shoot and root systems.
It stimulates cell elongation and division in the embryo, leading to the growth of the shoot and root meristems.
This process helps the emerging seedling to penetrate the soil and establish itself in the environment.
Thus, gibberellic acid is an essential hormone for maize seed germination, promoting the breakdown of stored nutrients and the growth and development of the embryo and seedling.