The predominant form of auxin naturally found in plants is indole-3-acetic-acid (IAA) and the chemical characterization of the endogenous molecule has allowed the development of synthetic analogs, such as
1-naphthylacetic acid (1-NAA) and 2,4-dichlorophenoxyacetic acid (2,4D), commonly used in physiological and genetic studies [3, 4] and as herbicides [1].