Question

Of the following which plant hormone inhibits growth?
A. Cytokinins
B. Gibberellins
C. Auxins
D. Abscisic acid

Answer 1

Hint: Many plant hormones lead to plant growth but some hormones inhibit or stop the growth of the plant.

Complete Answer:
The plant hormone, Abscisic acid inhibits the growth of the plant. Other hormones like Auxin, Gibberellins and cytokinins promote the growth of the plant. Abscisic Acid (ABA) is involved in closure of stomata, but seeds dormancy and inhibit other hormonal actions. It plays an important role in seed maturation. Abscisic acid has an important role in synthesis of proteins and compatible osmolytes, which enable plants to tolerate stresses due to environmental or biotic factors. It also acts as a general inhibitor of growth and metabolic activities. By measuring the growth of roots we estimate these growth hormones and stress hormone, Abscisic acid.

The correct option is D, Abscisic acid.

Additional Information: The growth hormone Cytokinins, Gibberellins, Auxins are responsible for plant growth. They are produced within the plant and occur in extremely low concentration. They control all aspects of plant growth and development, from embryogenesis, regulation of organ size, stress tolerance etc. Many factors can cause and effect the plant growth such as external (environmental) and some internal factors.

Note:Abscisic Acid inhibits plant growth and is important for regulating dehydration response in plants. Each plant cell is capable of producing hormones. Synthetic plant hormones are also used in different techniques involving plant propagation, cuttings, grafting and tissue culture. Embryo dormancy is characterized by a high ABA: GA ratio. ABA controls embryo dormancy, and GA embryo germination.