60. Which one of the following statements are TRUE for gibberellins?
A. Gibberellins promote seed germination
B. Gibberellins cannot stimulate leaf growth
C. Gibberellins cannot stimulate stem growth
D. Gibberellins can be exogenously used to increase plant growth
E. GA3 is predominantly used in agronomic and horticultural practices Choose the mostappropriate
answer from the options given below:
(a) A, B and C only
(b) A, C and E only
(c) A, D and E only
(d) B, C and D only

Introduction

Gibberellins (GAs) are a group of plant hormones that play an essential role in promoting various aspects of plant growth, including seed germination, stem elongation, and overall plant development. Understanding the true functions of gibberellins is crucial for their application in agriculture and horticulture. In this article, we’ll explore the characteristics of gibberellins and clarify some common misconceptions about their role in plants.

Functions of Gibberellins

Gibberellins are involved in a range of processes that promote plant growth. Here are some of the key functions:

1. Promotion of Seed Germination: Gibberellins are critical for breaking seed dormancy and promoting germination. They activate the enzymes responsible for breaking down stored food reserves in seeds, providing energy for the growing plant.

2. Stem Elongation and Leaf Growth: Gibberellins stimulate both stem elongation and leaf growth, making them vital for overall plant size and structure.

3. Application in Agriculture: Exogenously applied gibberellins, such as GA3, are commonly used in agronomic and horticultural practices to promote growth, improve crop yield, and increase the size of fruits and flowers.

Analyzing the Given Statements

Let’s review the given statements about gibberellins:

• A. Gibberellins promote seed germination: This statement is true. Gibberellins play a critical role in breaking seed dormancy and promoting germination.

• B. Gibberellins cannot stimulate leaf growth: This statement is false. Gibberellins actually stimulate leaf growth by promoting cell division and elongation.

• C. Gibberellins cannot stimulate stem growth: This statement is false. Gibberellins are well-known for their ability to stimulate stem elongation and promote overall growth.

• D. Gibberellins can be exogenously used to increase plant growth: This statement is true. Gibberellins, particularly GA3, are widely used in agriculture to enhance plant growth and improve crop yields.

• E. GA3 is predominantly used in agronomic and horticultural practices: This statement is true. GA3 is one of the most commonly used forms of gibberellin in agricultural and horticultural applications to promote growth.

Conclusion

Based on the analysis of the statements:

• Statements A, D, and E are true, while B and C are false.

Thus, the most appropriate answer is:

Correct Answer: (c) A, D, and E only