It was the first significant plant hormone to be discovered. In an experiment in the early 1880s, Charles Darwin and his son Francis observed that canary grass coleoptiles bend towards the light source when light is introduced from one direction. Based on the works of Darwin, in 1928, Dutch botanist Fritz Went showed that this bending of light was promoted by a hydrophilic mobile signal which he isolated from an oat coleoptile. He named this substance auxin.
Where is it Produced
Chemical structure
How Does Auxin Work
Functions
Commercial Applications
Apart from these natural auxins, some chemicals have been produced synthetically, showing activities similar to IAA. Naphthalene acetic acid (NAA), 2,4-Dichlorophenoxyacetic acid (2,4-D), and Indole-3-butyric acid (IBA) are some of the synthetic auxins. On the other hand, during geotropism, more auxin molecules gather in the lower side of the stem, sensing gravity. The lower part of the stem grows against gravity, resulting in the upright positioning of the plant.
