Inhibition of phytoene desaturase — the mode of action of certain bleaching herbicides

Abstract

Assay systems have been developed in order to differentiate betw een the m odes of action of certain bleaching herbicides. These include inhibition of chlorophyll or carotenoid biosynthesis, and initiation of pigment degradation. Herbicidal com pounds with phytoene desaturase as their primary target site were investigated in a cell-free carotenogenic system from Aphanocapsa. In a comparative study, the structural prerequisites for inhibition of phytoene desaturase were established for both benzophenone analogs and various m-phenoxybenzam ides. This inhibitory action of the latter compounds is enhanced by lipophilic groups with certain steric properties. © 1984, Walter de Gruyter. All rights reserved.