Name: Vernalisation- an overview
Uploaded: 2019-07-19
Duration: 7 min 50 s
Description: Vernalisation is the phenomenon of cold exposure that provides some plants with the ability to flower in the best season. Let’s learn about these cold memori...

Question

Write about the functions of auxins.

Accepted Answer

Plant growth regulators are the organic compounds synthesised in plants naturally and required in very minute quantities. It regulates certain physiological functions in plants. Auxin is a plant growth regulator that was the first plant hormones to be discovered. It is produced in the shoot and root apices and they migrate from the apex to the site of action.

The functions of auxins are the following:

i) Cell division and elongation: The auxin helps in the cell division and cell elongation in the shoots. It is an important hormone in the secondary growth of stem and differentiation of xylem elements.
ii) Apical dominance: In certain plants, when the terminal bud is intact and growing, the growth of lateral buds becomes suppressed. If the apical bud is removed, that results in the rapid growth of lateral buds. The phenomenon in which the apical bud does not allow the lateral buds to grow is called apical dominance. It is because of auxin produced at the terminal bud and which is transported downward through the stem to the lateral buds and prevent growth.
iii) Abscission: Auxins prevent the formation of the abscission layer which may otherwise result in the premature fall of leaves, flowers and fruit.

iv) Root initiation: Auxin stimulates root initiation on stem cuttings. This is used as a rooting hormone in tissue culture.
v) Parthenocarpy: The fruit formation without fertilization is called parthenocarpy. Auxin can induce the formation of parthenocarpic fruits. In parthenocarpic fruit, the concentration of auxin in the ovary is higher than in the ovaries of plants that produce fruits by the way of fertilization.
vi) Weedicide: Some synthetic auxins are very useful for the eradication of weeds from the farmer's field. Example: 2,4-D.

Write about the functions of auxins.

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