Gibberellic acid

A plant hormone that promotes growth and development

Gibberellic acid (GA) is a naturally occurring plant hormone belonging to the gibberellin family. It plays a crucial role in various developmental processes in plants, including seed germination, stem elongation, leaf expansion, and flowering.

Chemical Structure

Gibberellic acid is a diterpenoid compound with the chemical formula C₁₉H₂₂O₆. It is one of the most well-studied gibberellins and is often used in agricultural practices to enhance plant growth.

Biosynthesis

Gibberellic acid is synthesized in plants from geranylgeranyl diphosphate (GGDP) through a series of enzymatic reactions. The biosynthesis occurs primarily in young tissues, such as developing seeds, young leaves, and root tips.

Functions in Plants

Gibberellic acid is involved in several key physiological processes:

Seed Germination

GA promotes the germination of seeds by breaking seed dormancy and stimulating the production of enzymes that degrade stored food reserves in the seed.

Stem Elongation

One of the most notable effects of gibberellic acid is its ability to promote stem elongation. It stimulates cell division and elongation, leading to increased plant height.

Leaf Expansion

Gibberellic acid facilitates leaf expansion by promoting cell growth and division, resulting in larger leaf size.

Flowering

GA influences the transition from vegetative to reproductive growth, thereby inducing flowering in certain plant species.

Applications in Agriculture

Gibberellic acid is widely used in agriculture to improve crop yields and quality. It is applied to:

• Enhance fruit size and quality in crops like grapes and citrus.
• Promote uniform seed germination and seedling growth.
• Increase the malting quality of barley by stimulating enzyme production.

Safety and Environmental Impact

Gibberellic acid is considered safe for use in agriculture when applied according to recommended guidelines. It is biodegradable and does not accumulate in the environment.

Related Pages

• Plant hormone
• Gibberellin
• Seed germination
• Stem elongation