Natural auxin refers to a class of plant hormones, specifically plant growth regulators, synthesized by plants themselves. These hormones are primarily derived from the amino acid tryptophan. The most common and vital natural auxins include Indole-3-acetic acid (IAA) and Indole butyric acid (IBA).
Auxins play a crucial role in numerous aspects of plant growth and development, including:
- Cell elongation: Auxins promote cell growth, leading to stem and root elongation.
- Apical dominance: They inhibit the growth of lateral buds, ensuring the main stem grows stronger.
- Root initiation: Auxins stimulate the formation of roots, essential for plant anchorage and nutrient uptake.
- Tropic responses: They influence plant responses to environmental stimuli like light (phototropism) and gravity (gravitropism).
- Fruit development: Auxins are involved in fruit set and enlargement.
While synthetic auxins exist (used in horticulture and agriculture), natural auxins are those produced within the plant itself, contributing to its inherent growth processes. Understanding these natural hormones helps in comprehending plant physiology and manipulating plant growth effectively.
