RESUMO
Literary data on correlation between the structure and auxin activity of aryl-, arylalkan- and aryloxyalkancarboxylic acids and those of 3-indolylacetic acid are reviewed. The structure of auxins is compared to that of their inactive structural analogs in terms of a literary hypothesis on the bifunctional binding of auxins to the receptor, which allowed to construct a model for the structure of the auxin receptor (site responsible for intrinsic binding of auxins). The geometric parameters of this receptor site and specific arrangement of specific auxin binding sites have been proposed. It is demonstrated that during auxin absorption on the receptor the conformation of the latter is changed, which may be accounted for as a primary functional effect of auxins on the receptor.