Question:

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

Updated On: Jun 23, 2024

  • Kinetin

  • Ethylene

  • 2, 4-D

  • GA3

Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is B

Solution and Explanation

Ethylene is a plant hormone that plays a significant role in promoting elongation of internodes and petioles in deep water rice (also known as flood-tolerant rice or floating rice). When the rice plants are submerged in water, they sense the reduced oxygen levels, which triggers the production of ethylene. Ethylene induces elongation growth in the internodes and petioles, allowing the rice plant to reach the water surface to access oxygen for survival. This adaptation helps deep water rice to cope with flooding conditions and maintain its growth and development even in flooded environments.
Therefore, The correct option is (B): Ethylene

Was this answer helpful?
2
1

Top Questions on plant growth and development

View More Questions

Questions Asked in NEET exam

View More Questions

Concepts Used:

Plant Growth Regulators

What is a plant growth regulator?

Plant growth regulators (PGRs) are chemicals used to modify plant growth such as increasing branching, suppressing shoot growth, increasing return bloom, removing excess fruit, or altering fruit maturity.

Types of Plant Growth:

There are the following types of plant growth.

  • Primary and Secondary Growth: The growth of a plant is termed primary when the same happens through the mitotic division of the meristematic cells which are present at the root and the shoot of the plants. 

Whereas, the secondary growth in a plant takes place through the division of the secondary meristem, which, in turn increases the diameter of the body of the plants.

  • Primary and Secondary Plant Growth
  • Unlimited Growth
  • Limited Growth
  • Vegetative Growth
  • Reproductive Growth

The five groups of plant growth regulators used in fruit crops include:

  1. Auxins: Auxins are one of the most important plant hormones. The chief naturally occurring auxin is indole-3 acetic acid – IAA and other related compounds.
  2. Gibberellins: Gibberellins are an extensive chemical family based on the ent-gibberellane structure. The first gibberellin to be discovered was gibberellic acid. Now there are more than 100 types of gibberellins.
  3. Cytokinins: These are produced in the regions where cell division occurs; mostly in the roots and shoots. They help in the production of new leaves, lateral shoot growth, chloroplasts in leaves etc.
  4. Absicisic Acid: Absicsic acid controls the dormancy of buds and seeds, inhibits shoot growth and is involved in regulating water loss from plants.
  5. Ethylene: Ethylene is a simple, gaseous plant growth regulator, synthesised by most of the plant organs includes ripening fruits and ageing tissues.