Inhibition of <i>Echinochloa crus‐galli</i> var. <i>frumentacea</i> seedling root elongation by chiral 1, 3, 5‐triazines in the dark

Abstract

Abstract 2‐z‐Substituted benzylamino‐4‐substituted‐amino‐6‐chloro‐1,3, 5‐triazines are herbicidal compounds showing leaf‐burning and/or growth inhibition with concomitant greening and stunting. Effects of chiral 1,3,5‐triazine compounds in a light‐independent seedling root elongation test with Echinochloa crus‐galli var. frumentacea Wight demonstrated an interaction between chirality and root growth inhibition. The test compounds inhibited root growth, and this inhibition was due to interference with a system or systems other than photosynthesis. 4‐( R )‐sec‐butylamino‐2‐(α,α‐dimethylbenzyl)amino‐6‐chloro‐1,3, 5‐triazine showed the highest inhibitory activity, and 4‐methylamino‐2‐( R )‐a‐methylbenzylamino‐6‐chloro‐1,3,5‐triazine was second. The chiral requirement for a strong inhibition of root growth was the (R)‐configuration, contrasting with the requirement for the (S)‐configuration for an inhibition of photosystem II.