Question

Describe physiological effect and applications of gaseous hormone in plants.

Hint:

Ethylene is produced in fruits and stressed tissues; its action is regulated by concentration and receptor sensitivity.

Answer 1

Step 1: Physiological Effects of Ethylene: Ethylene, the gaseous plant hormone, influences: 1. Fruit ripening: Triggers ripening by inducing gene expression for enzymes like pectinase, softening fruits (e.g., bananas). 2. Senescence: Promotes leaf and flower senescence, abscission of leaves/fruits. 3. Stress response: Enhances responses to wounding, flooding, or pathogen attack (e.g., aerenchyma formation in roots). 4. Growth regulation: Inhibits stem elongation, promotes lateral swelling, and induces epinasty (leaf drooping). Step 2: Applications: 1. Controlled fruit ripening (e.g., ethylene gas for bananas in storage). 2. Preventing premature abscission in crops (e.g., cherries). 3. Inducing flowering in pineapples for synchronized harvests. 4. Enhancing senescence for easier harvesting (e.g., cotton defoliation).