Difference Between Auxin and Gibberellin

The difference between auxin and gibberellin lies in the plant parts they target for growth. Both Auxin and Gibberellins are plant hormones. Every cell in a plant has the potential to make plant hormones. For a plant to germinate, auxin and gibberellins are both required.

Auxin helps promote root growth and gibberellin promotes shoot growth. Both auxin and gibberellins are similar in some manner as they are both involved in the development of plants through cell expansion. In this article, we will read about the differences between auxin and gibberellin along with some similarities.

What is Auxin?

The Greek verb auxin, meaning “to grow,” is where the name “auxin” comes from. In phototropism and gravitropism, auxins are the primary hormones responsible for cell elongation. Additionally, they control how meristems differentiate into vascular tissue and support the growth and arrangement of leaves. Indole acetic acid (IAA) is the only naturally occurring auxin that has physiological activity, but numerous synthesized auxins are utilized as herbicides.

Auxins generated in the apical meristem cause apical dominance, which inhibits the development of lateral buds. IAA is a rooting hormone that is used to encourage the establishment of accidental roots on cuttings and severed leaves. In greenhouse tomato plants, synthetic auxins encourage healthy fruit development. Other plant responses under the direct or indirect regulation of auxins include flowering, fruit setting ripening, and preventing abscission (leaf falling).

What is Gibberellin?

Gibberellins (GAs) are a family of roughly 125 closely related plant hormones that promote fruit and blossom ripening, shoot elongation, and seed germination. Young leaves, seed embryos, and the apical meristems of roots and stems all produce GAs. GA antagonists are sometimes used on trees beneath power lines in metropolitan areas to restrict growth and lessen the need for pruning.

The seeds of plants that require exposure to cold or light to germinate are released from their state of dormancy, which is characterized by limited growth and development. Gender expression, the growth of seedless fruit, and the postponement of senescence in leaves and fruit are additional effects of GAs. GA is frequently applied to maturing grapes to encourage increased fruit size and looser bunches (longer stems), which lowers the likelihood of mildew infection.

Difference Between Auxin and Gibberellin

The following table highlights the differences between Auxin and Gibberellin:

Characteristic	Auxin	Gibberellin
Structure	Auxin has an unsaturated structure and either a single or double side chain.	The structure of gibberellin is a saturated, side-chain-free tetracyclic gibbane.
Discovered in	Higher plants.	Both higher plants and in fungi.
Root Growth	Inhibits root growth at normal concentrations.	Has no effect on root growth.
Shoot Growth	Promotes the expansion of shoot segments.	Promotes the healthy shoot’s growth.
Leaf Growth	Has little effect on the development of leaves.	Increases the rate of leaf growth
Seed and Bud Dormancy	Does not break dormancy in seeds and buds	Gibberellin is essential for seed germination because it induces bud and seed dormancy.
Callus Growth	It is crucial for the development of callus.	It has no effect on the development of the callus.
Transport	Basipetal transport is used.	Both basipetal and acropetal transport is used
Hormonal Effects	It has a hormonally feminizing impact.	It has a hormonally masculine impact.
Functions	Axial elongation Cell division Differentiation Cellular expansion Lateral expansion	Stem elongation Seed germination Fruit senescence Breaks Dormancy Enzyme Induction

Similarities Auxins and Gibberellins

The following similarities are seen in Auxin and Gibberlins:

• Both Auxin and Gibberellin help in promoting plant growth by elongating various parts of the plant.
• Cell Expansion is carried out both by both Auxin and Gibberellin.
• Both these hormones are often seen interacting synergistically to each other.
• Both Auxin and Gibberellin are involved in the process of seed germination.
• Auxin is directly involved in phototropism and geotropism. Gibberellin supports the tropism through cell elongation.

Conclusion – Difference Between Auxin and Gibberellin

Auxin and Gibberelin are both plant hormones that help in plant’s growth. Auxin helps in axial elongation, cell division, and cell differentiation. On the other hand, gibberellin is involved in stem elongation, seed germination, and dormancy. During seed germination, auxin helps in root growth and Gibberelin assists in stem growth.

Difference Between Related Links

Difference Between Apogamy and Apospory	Difference Between Sporophyte and Gametophyte
Difference Between Simple And Complex Tissue	Difference Between Ectomycorrhizae and Endomycorrhizae
Difference Between Plant and Tree	Difference Between Protostomes and Deuterostomes
Difference Between Pollination and Fertilization	Difference Between Sexual And Asexual Reproduction
Difference Between Radicle and Plumule	Difference Between Aerobic And Anaerobic Bacteria

FAQs on Auxin and Gibberellin

What Part does Auxin play in Gravitropism and Phototropism?

Auxin encourages tropism by producing movement in reaction to light, gravity, and touch, or phototropism, gravitropism, and thigmotropism. 

Does Gibberellin Promote Root Growth?

Gibberellins promote root growth by controlling cell division and promoting cell extension. Auxins are considered the primary hormones for root growth.

How does Auxin Affect Leaf Growth?

Auxin is responsible for the shape of the leaves in plants and also for the pattern seen in veins.

How does Gibberellin Interact with Auxin?

Gibberellin interacts with Auxin in a positive manner. They both work synergistically. Auxins affects the synthesis of Gibberelins.

What Happens if There is Too Much Auxin in the Plant?

Too much auxin in a plant can lead to the death of the plant and it also causes stimulation of ethylene which can cause reduced root growth.

What is the Common Function of Auxin and Gibberellin Class 10?

The common function between auxin and gibberellin is that both promote cell elongation in plants.

What are the Commercial Uses of Auxin and Gibberellin?

Auxin is used in rooting hormone formulations for plant propagation, while Gibberellin is used to promote uniform fruit ripening and increase crop yields.