Question

Write an account of "Auxins" as growth regulator.​

Answer 1

Answer:

In normally growing plants, the auxin phytohormones are responsible for phototropism and apical dominance. They also influence abscission of blooms, leaves, and fruit, making them valuable tools in bringing fruits and horticultural products to market. Auxins are widely used in plant propagation and tissue culture

Answer 2

Explanation:

• Auxins are weak organic acids produced naturally by plants and are capable of promoting cell elongation during the growth of stem and roots.

• Auxins are not catalysts as they are used up in growth process.

• Auxins are produced in shoot tips, root tips, young leaf primordia, etc.

• They migrate to the elongation region from their synthesizing region.

• Auxins are inactivated by light.

• Auxins are translocated in polar manner, i.e. from morphological apex to base.

• In stems, the translocation of auxin takes place in downward direction, while in roots, it is in upward direction.

• Auxins may be natural or synthetic.

• Example of natural auxins are Indole-3-acetic acid (IAA) and its derivatives; whereas synthetic auxins are NAA, 2,4-D, 2, 4, 5 - T, etc.

• Lower concentration of Auxin promotes growth of roots and axillary bud, whereas higher concentration is required for stem growth.