What Is the Difference Between Auxin and Gibberellin in Terms of Function and Effects
Botany is a subject related to the study of plants. This subject got increased importance in the field of science as plant growth and maintenance require more attention after various disturbances created in the natural ecosystem by human beings.
In this article, we shall be learning about important concepts related to Auxin and Gibberellin.
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 an organic substance and not any form of active nutrients. Similar to human and animal hormones, 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 synthesized 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 their 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
Difference between Auxin and Cytokinin
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-dichloro phenoxy acetic acid indole butyric acid and naphthalene acetic acid.
FAQs on Difference Between Auxin and Gibberellin in Plant Growth and Development
1. What is the main difference between auxin and gibberellin?
The main difference between auxin and gibberellin is that auxin primarily promotes cell elongation and apical dominance, while gibberellin mainly stimulates stem elongation, seed germination, and flowering.
- Auxin: Promotes cell elongation, root initiation, and apical dominance.
- Gibberellin: Promotes stem elongation, seed germination, and breaking of dormancy.
- Both are essential plant growth hormones but differ in their specific physiological roles.
2. What is auxin and what does it do in plants?
Auxin is a plant growth hormone that regulates cell elongation and directional growth in plants.
- The main natural auxin is Indole-3-acetic acid (IAA).
- Promotes cell elongation in shoots.
- Maintains apical dominance by inhibiting lateral buds.
- Stimulates root initiation and fruit development.
3. What is gibberellin and what is its function?
Gibberellin is a plant hormone that promotes stem elongation, seed germination, and flowering.
- First discovered as Gibberellic acid (GA3).
- Stimulates internode elongation in stems.
- Breaks seed dormancy and promotes germination.
- Induces flowering in some long-day plants.
4. How do auxin and gibberellin affect stem growth differently?
Auxin promotes stem growth by cell elongation, while gibberellin promotes both cell elongation and cell division in stems.
- Auxin: Increases cell wall plasticity, leading to elongation.
- Gibberellin: Stimulates elongation and division in internodes.
- Gibberellin has a stronger effect on increasing plant height.
5. What role do auxin and gibberellin play in seed germination?
Gibberellin directly promotes seed germination, whereas auxin plays a minor or indirect role.
- Gibberellin: Stimulates production of enzymes like amylase that break down stored food.
- Breaks seed dormancy in many species.
- Auxin: Mainly supports early seedling growth after germination.
6. How are auxin and gibberellin transported in plants?
Auxin shows polar transport, while gibberellin is transported non-polarly through vascular tissues.
- Auxin: Moves in a polar manner from shoot tip downward.
- Gibberellin: Moves through xylem and phloem in both directions.
- Auxin transport is more direction-specific compared to gibberellin.
7. What are some examples of auxin and gibberellin?
Examples of auxin include Indole-3-acetic acid, while examples of gibberellin include Gibberellic acid (GA3).
- Auxin examples: Indole-3-acetic acid (IAA), Indole-3-butyric acid (IBA), Naphthalene acetic acid (NAA).
- Gibberellin examples: GA1, GA3, GA4.
- These hormones are widely used in agriculture to regulate plant growth.
8. Do auxin and gibberellin work together in plants?
Yes, auxin and gibberellin often interact synergistically to regulate plant growth and development.
- Both promote stem elongation.
- Auxin can stimulate gibberellin biosynthesis in some tissues.
- Together they regulate processes like fruit development and flowering.
9. How do auxin and gibberellin influence fruit development?
Auxin initiates fruit development, while gibberellin enhances fruit growth and size.
- Auxin: Triggers fruit set after fertilization.
- Gibberellin: Promotes enlargement of fruit tissues.
- Both can induce parthenocarpy (seedless fruit formation).
10. Why are auxin and gibberellin important in agriculture?
Auxin and gibberellin are important in agriculture because they regulate plant growth, increase yield, and improve crop quality.
- Auxin: Used for root formation, weed control (synthetic auxins), and fruit development.
- Gibberellin: Used to increase plant height, break seed dormancy, and enhance fruit size.
- Both hormones help optimize crop productivity.
