Chelating Agents as Growth Substances

Abstract

SINCE the article¹ under the above title was published, we have obtained further biological evidence bearing on the mode of action of auxin. We carried out two root-growth experiments exactly similar to those of 23.3.56 and 21.4.56 (Tables 4 and 5, loc. cit.) but using 8-hydroxyquinoline and ethylene-diaminetetra-acetate instead of 3-indolylacetic acid and ethylenediaminetetra-acetate. Essentially similar results were obtained, that is, the inhibition of root growth caused by 10⁻⁵ M 8-hydroxyquinoline or 10⁻⁵ M ethylenediaminetetra-acetate alone was largely prevented by the presence of 10⁻¹¹ M ethylenediaminetetra-acetate in the former case or of 10⁻¹¹ M 8-hydroxyquinoline in the latter.