Which of these compounds can induce seed dormancy?

The correct answer is ABA (Abscisic acid).

Understanding Seed Dormancy:
Seed dormancy is a physiological state in which viable seeds are temporarily prevented from germinating, even when placed under favorable environmental conditions such as moisture, warmth, and oxygen. This mechanism is crucial for survival, ensuring that seeds only germinate when conditions are optimal for the seedling to grow and establish.

The Role of Abscisic Acid (ABA):
Abscisic acid (ABA) is a key plant hormone (phytohormone) responsible for promoting and maintaining seed dormancy. During the maturation stage of seed development, ABA accumulates in high levels within the embryo. ABA inhibits the production of germination-inducing enzymes (such as amylase, which breaks down stored starches into sugars). By suppressing these germination pathways, ABA keeps the seed in a dormant state, protecting it from germinating prematurely during unfavorable seasons.

Why the Other Options Are Incorrect:
• Gibberellins: These hormones act antagonistically to ABA. They stimulate the synthesis of hydrolytic enzymes needed for germination, effectively breaking seed dormancy and promoting growth.
• Ethylene: Ethylene is a gaseous phytohormone that is often associated with breaking dormancy and promoting the germination of seeds in many plant species.
• Potassium nitrate: This is a chemical compound frequently used in agriculture to break seed dormancy and accelerate uniform germination rather than inducing dormancy.