What applications do gibberellins have in agriculture, such as ending seed dormancy, promoting flowering, and increasing fruit size?

Sourav PanNovember 12, 2024

Answered

Gibberellins (GAs) are a class of plant hormones that play a vital role in regulating various aspects of plant growth and development. Their applications in agriculture are diverse and impactful, particularly in enhancing seed germination, promoting flowering, and increasing fruit size. Here’s a detailed overview of these applications:

1. Ending Seed Dormancy

• Breaking Dormancy: Gibberellins are crucial for breaking seed dormancy, which is essential for initiating germination. They promote the synthesis of enzymes such as α-amylase that degrade stored starches in the seed, making nutrients available to the developing embryo. This process allows seeds to germinate more effectively under favorable conditions.
• Exogenous Application: Applying gibberellins externally can effectively stimulate germination in dormant seeds, enabling faster seedling production and improving crop establishment. This is particularly useful for crops that have naturally high dormancy levels.

2. Promoting Flowering

• Flower Induction: Gibberellins play a significant role in promoting flowering in various plant species. They can activate specific genes involved in floral development, influencing the differentiation of floral buds . For example, in Arabidopsis, exogenous application of gibberellins accelerates flowering, especially under short day conditions where flowering would typically be delayed due to low endogenous GA levels .
• Biennial Plants: In biennial plants that require cold temperatures to flower, gibberellins can induce flowering regardless of temperature conditions, allowing for more flexible growing schedules .

3. Increasing Fruit Size

• Fruit Development: Gibberellins are known to enhance fruit growth by promoting cell division and elongation. This results in larger fruit sizes and improved quality . For instance, applying gibberellins to grapevines can significantly increase berry size, improving marketability.
• Seedless Fruits: Gibberellins can also induce parthenocarpy (the development of fruit without fertilization), leading to the production of seedless varieties of fruits like grapes and cucumbers. This is particularly desirable for consumer preference and market demand.

4. Other Applications

• Stem Elongation: Gibberellins promote stem elongation by stimulating cell division and loosening cell walls, which can be beneficial for crops that require taller growth forms for better light capture .
• Leaf Expansion: They facilitate leaf expansion, contributing to increased photosynthetic capacity and overall plant vigor.
• Stress Response: Gibberellins help plants cope with various stress conditions by regulating growth responses, which can enhance resilience against environmental challenges