Indole-3-Acetic Acid (IAA)

Indole-3-acetic acid (IAA) is a naturally occurring plant hormone and one of the most abundant and essential auxins found in plants. Auxins are a class of plant hormones responsible for regulating various aspects of plant growth and development. IAA plays a crucial role in controlling cell division, elongation, and differentiation in plants.

Key functions and effects of indole-3-acetic acid (IAA) include:

1. Cell elongation: IAA stimulates the elongation of cells, promoting the growth of plant tissues. This is especially important in the growth of stems and young leaves.

2. Apical dominance: IAA inhibits the growth of lateral buds near the apical meristem (the tip of a growing shoot). This phenomenon is known as apical dominance and ensures that the main stem grows taller and stronger, while lateral branches remain suppressed.

3. Tropisms: IAA is responsible for various tropisms in plants, including phototropism (response to light) and gravitropism (response to gravity). It helps guide the direction of growth in response to environmental stimuli.

4. Root development: IAA plays a crucial role in root development and root branching. It influences the formation of lateral roots and root hairs, contributing to an extensive root system.

5. Flowering and fruit development: IAA is involved in the regulation of flowering and fruit development. It affects flower initiation, pollen development, and fruit growth.

6. Cell differentiation: IAA influences cell differentiation, directing undifferentiated cells to become specialized cells with specific functions.