indool3etsüülasiinhapet

Indool-3-üülasiinhapet, often abbreviated as IAA, is a naturally occurring plant hormone belonging to the auxin class. It is synthesized in the apical meristems of plants, such as shoot and root tips, and is crucial for various growth and developmental processes. IAA plays a significant role in cell elongation and division, influencing plant architecture, including the formation of roots and shoots.

This hormone is transported throughout the plant in a polar, unidirectional manner, primarily from the apex downwards. Its effects are concentration-dependent, with optimal levels promoting growth while supraoptimal concentrations can inhibit it. IAA is involved in phototropism, the bending of plants towards a light source, and gravitropism, the response to gravity. It also mediates the formation of lateral roots and adventitious roots, and plays a role in fruit development and abscission (the shedding of leaves and fruits).

The synthesis of IAA involves the amino acid tryptophan. Once produced, it can be conjugated with sugars or amino acids to form inactive storage forms, which can later be released to become active again. The degradation of IAA also occurs, allowing for precise regulation of its levels within plant tissues. Understanding IAA's functions is vital in agricultural and horticultural practices, informing strategies for plant growth regulation and crop yield enhancement.