Studies on the Relation between Molecular Structure and Physiological Activity of Plant Growth-Regulators. I. Abscission-Inducing Activity

Abstract

Excision of the terminal bud of the seedling of Phaseolus vulgaris var. Black Valentine results in the formation of an abscission layer in the subjacent internode. A similar result can be induced by appln. of various chemicals to the intact bud. The most effective compounds found, in tests of more than 600 substances, were certain 2,3,5-trihalogenated benzoic acids; a large number of other compounds of considerable structural diversity also exhibit activity. The abscission-inducing activity of 2,3,5-triiodobenzoic acid can be counteracted by concurrent appln. of a number of compounds, including 3- indoleacetic acid and 1-naphthaleneacetic acid.