Difference Between Auxin And Gibberellin

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Plant Hormone

Plants contain chemical substances that are responsible for growth, development, reproduction, stress control and many other related activities. These chemical substances are the plant hormones that have single molecules and exist in very moderate quantities. It is also known as phytohormone, which is the organic substance and not any form of active nutrients. Similar to the human and animal hormone, it regulates different activities in the plant cell. These are produced in specific parts of the plants and carried to other parts where it evokes biochemical, psychological and morphological responses. There are mainly five subclasses identified in phytohormones: auxins, gibberellins, cytokinin, abscisic acid and ethylene. 

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Auxins and Gibberellins

Auxins and Gibberellins are two major classes of the hormone, which are plant growth regulators. The plant growth regulators are the hormones that manage and control all the aspects related to the plant’s growth and development. Both these hormones impact growth within the plant and take care of the development processes like flowering, root initiation, organogenesis, sex expression, etc. The physiological reactions of auxins and gibberellins show various effects. 


Auxins Definition 

Auxin hormones are produced naturally and synthesised artificially within the plants. This hormone is obtained from the amino acid called tryptophan. The term auxin means to enlarge or grow. These are typically located at the growing apices roots, and later it migrates to other parts of the plants to stimulate growth. This hormone has a crucial role to play in the development of the plant. 


Gibberellins Definition

Gibberellins are a variety of plant and fungal hormones which are acids by the chemical nature. These are a group of hormones that induces plant growth and development. Being a plant growth regulator, it looks after various processes like stem elongation, germination, flowering, enzyme induction, etc. Gibberellins have a dramatic effect on the growth that determines the height of a plant. 


Difference Between Auxin and Gibberellin

Differences

Auxins

Gibberellins

Plant Type

It is found mainly in higher plants.

It is found mostly in fungi and some higher plants. 

Shoot Growth

It supports growth in the shoot segments.

It supports growth in the shoot intact.  

Root Growth

It develops rooting on cutting. 

It has zero effect on rooting. 

Leaf Growth

The effect in the leaf’s growth is negligible.

The effect in the leaf’s growth is prominent. 

Bolting

It does not encourage any bolting activities.

It encourages bolting activities in rosette plants. 

Apical Dominance

It leads to apical dominance.

It doesn’t cause apical dominance. 

Structure

It is a single or double unsaturated structure ring. It contains a side chain. 

It has a tetracyclic gibbane structure. Unsaturation is comparatively less. It doesn’t contain any side chain. 

Stem Elongation

It has dwarf shoots that don’t elongate.

It had dwarf shoots that usually elongated. 

Seed and Bud Dormancy 

It does not promote breaking seed and bud dormancy.

It promotes seed germination,  breaking seed and bud dormancy.

Callus Growth

It plays a prominent role in callus growth. 

It has no role to play in callus growth. 

Root Formation

It helps in root formation.

It doesn’t help in root formation. 

Transport 

It follows basipetal transport.

It has both basipetal and acropetal transport.

Hormonal Effects

It has a feminising hormonal effect. 

It has a masculine hormonal effect.

Functions

Its main functions are axial elongation, cell division, cell differentiation, cellular expansion, lateral expansion and isodiametric expansion in plants.

Its main functions are stem elongation, seed germination, flowering, sex expression, dormancy, fruit senescence and enzyme induction.


Difference Between Auxin and Cytokinin

Difference

Auxin 

Cytokinin

Primary Role

It is mainly responsible for cell elongation.

It is mainly responsible for cell differentiation and cell division. 

Production 

It is formed at the root tip. 

It is formed in the root and later moves upward in the xylem sap. 

Root Branching (Lateral Root)

It promotes root branching.

It inhibits root branching.

Apical Dominance

It maintains apical dominance.

It has no role to play in apical dominance. 

Growth of Lateral Buds

It prohibits the growth of lateral buds.

It promotes the growth of lateral buds.

Other Functions

Its main functions are axial elongation, secondary root growth, apical dominance and fruit development in plants.

Its main functions are lateral bud development, cell division and cell development in plants.


Did You Know? 

The plant hormone auxin can exist naturally, or it can also be processed synthetically. The naturally occurring auxins are indole ethanol, indole acetic acid and indole acetaldehyde.

Synthetic auxins are sometimes used as growth inhibitors and are treated as a herbicide. It includes 2,4-dichlorophenoxyacetic acid indole butyric acid and naphthalene acetic acid. 

FAQ (Frequently Asked Questions)

Q1. What are Cytokinins?

Answer. Cytokinins are the plant hormones that promote cell division and cell differentiation in the plant root and shoot system. These are mostly detected in all thorny plants, and other organisms like mosses, fungi, bacteria and insects. The hormones are mainly produced at the meristem of the roots, and there are around 200 different varieties in both natural and synthetic form. It might promote cell division, but also maintains the level of protein that is essential for mitosis. The process of mitosis helps to replace the damaged cells daily, which further promotes growth. So, it also promotes cell development and growth that affects apical dominance and leaf senescence. 

Q2. What are some common uses of Gibberellins?

Answer. Gibberellins are commercially obtained from the fungi that facilitate the quick germination of seeds. Some plants also produce gibberellins, but the quantity is very little compared to the ones obtained from the fungi. It is useful for the farm owners of vineyards as it increases the harvest tremendously. This is because when the gibberellins molecules are sprayed in the vines, it raises the amount of sugar and water content in each fruit. It equally promotes the growth of dwarf species which can be developed quickly by applying gibberellins. In plants like cucumber, gibberellins produce the male flowers that are used to get pollen of desired characteristics.