(2-Chloroethyl) Trimethylammonium Chloride and Related Compounds as Plant Growth Substances. II. Effect on Growth of Wheat.

In this series of publications, the action of (2chloroethyl)trimethylammonium chloride and certain other compounds structurally related to the quaternary ammonium cation, (CH3),3N + CH2-CH2X, are described as a class of plant growth substances. In the first paper (1), compounds were examined for biological activity by an assay with wheat seedlings which involved the measurement of the distance between the bases of the first two leaf blades. Three very active and closely related compounds were discovered in which X was a chloro, bromo or = CH2 group, namely, (2-chloroethyl) trimethylammonium chloride, (2-bromoethyl) trimethylammonium bromide and (2,3-n-propylene) trimethylammonium bromide.3 The growth of wheat plants after various treatments with the three most active derivatives is described in this paper. The most characteristic growth change was a reduction in height of plants accompanied by an increase in stem diameter. In most respects the growth alterations after treatment with derivatives related to (2-chloroethyl) trimethylammonium chloride were the opposite from that obtained with gibberellin, and in addition, these effects were reversed by gibberellin. In fact, the actions of gibberellin and (2-chloroethyl) trimethylammonium chloride on the growth of plants have been found to be mutually antagonistic.