A Non-Metabolic Model of Acifluorfen Activity

Abstract

The para-nitro substituted diphenyl ether herbicides which cause rapid plant pigment photo-bleaching can be divided into two categories: 1. those that have a photosynthetic requirement for activity (e.g. oxyfluorfen) and 2. those that have no apparent metabolic requirement for activity (e.g. acifluorfen). A model is presented for the latter category, in which the diphenyl ether herbicide interacts with carotenoids and/or chlorophyllide in plastid membranes to form a complex which photochemically generates singlet oxygen or lipid-peroxidizing radicals.