Gibberellic acid

Definition

Gibberellic acid is a plant hormone, specifically a type of gibberellin, that plays a critical role in promoting growth and development in plants. It affects various physiological processes such as seed germination, stem elongation, and flowering. By regulating these processes, gibberellic acid helps plants adapt to their environment and optimizes their growth potential.

5 Must Know Facts For Your Next Test

1. Gibberellic acid was first discovered in the 1930s from a fungus called Gibberella fujikuroi, which caused the 'foolish seedling' disease in rice.
2. This hormone can significantly increase plant height by promoting cell division and elongation in stems.
3. Gibberellic acid also plays a vital role in breaking seed dormancy, allowing seeds to germinate under favorable conditions.
4. It is commonly used in agriculture and horticulture to enhance crop yields and improve fruit size and quality.
5. Gibberellic acid can influence the timing of flowering, helping plants adapt to seasonal changes for optimal reproduction.

Review Questions

• How does gibberellic acid influence seed germination and overall plant growth?
  • Gibberellic acid influences seed germination by breaking dormancy and triggering the metabolic processes necessary for growth. It activates enzymes that break down stored starches into sugars, providing energy for the emerging seedling. Additionally, this hormone promotes stem elongation by stimulating cell division and elongation, resulting in taller plants. This ability to enhance both germination and growth makes gibberellic acid essential for plant development.
• Discuss the agricultural applications of gibberellic acid and its impact on crop production.
  • Gibberellic acid is widely used in agriculture to improve crop production through various means. Farmers apply it to enhance seed germination rates, promote uniform growth, and increase fruit size. For example, it can help grapes grow larger and more evenly spaced on the vine. This hormone can also help crops overcome environmental stresses by promoting vigorous growth, ultimately leading to higher yields and better quality produce.
• Evaluate the role of gibberellic acid compared to other plant hormones in regulating plant growth and development.
  • Gibberellic acid plays a distinct yet complementary role compared to other plant hormones like auxins and abscisic acid. While gibberellic acid primarily promotes growth and development through stem elongation and seed germination, auxins are crucial for regulating directional growth toward light (phototropism) and root development. In contrast, abscisic acid generally inhibits growth and triggers stress responses like dormancy during unfavorable conditions. Understanding how these hormones interact allows us to appreciate the complex regulatory network that governs plant biology.

Related terms

Gibberellins: A group of plant hormones that promote stem elongation, seed germination, and other growth-related processes.

Abscisic acid: A plant hormone that generally inhibits growth and promotes seed dormancy and stress responses.

Auxins: Plant hormones that regulate various aspects of growth, including cell elongation, root formation, and fruit development.