Question

Which hormone promotes internode/petiole elongation in deep water rice?

Options

• Kinetin

• Ethylene

• 2, 4-D

• GA₃

Answer 1

Ethylene

Explanation:

Ethylene is a plant hormone that regulates a variety of activities during plant growth and development. It is well-known for its effect on fruit ripening and has significant commercial value in agriculture. When rice plants remain underwater, they detect low oxygen levels and produce ethylene. Ethylene increases internode/petiole elongation in deepwater rice plants, keeping the leaves and other upper parts above water. This enables the rice plant to obtain oxygen for survival. It enables the rice plant to withstand flooding conditions while continuing to grow and develop.