Abstract

This study compares 212 molecular descriptors of four auxins (indolebutyric acid; indoleacetic acid; 2,4-dichlorophenoxyacetic acid; 1-naphthaleneacetic acid), three auxin transport inhibitors [2-(naphthalen-1-ylcarbamoyl)benzoic acid; 2,3,5-triiodobenzoic acid; 9-hydroxy-9H-fluorene-9-carboxylic acid], and five competitors for auxin receptors [2-(2,4,6-trichlorophenoxy)acetic acid; 2-(4-chlorophenoxy)-2-methylpropanoic acid; 3-phenylpropanoic acid; 3-(2-chlorophenoxy)butanoic acid; 2-amino-3-(5-methyl-1H-indol-3yl) propanoic acid]. The analysed compounds did not show statistically significant differences in any of those descriptors, suggesting that chemical and structural differences, per se, do not determine their functional diversities. We propose that combination with other, yet unknown chemical groups confers the specificity necessary for these molecules to act as auxins, as auxin transport inhibitors or auxin receptor competitors