Stimulation of nadph-dependent lipid peroxidation by 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid and diquat in microsomes isolated from Pisum sativum

Abstract

2,4-Dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and diquat (DQ) stimulate NADPH-dependent lipid peroxidation (in the presence of ADP-Fe²⁺ complex) in microsomes from green leaves and etiolated seedlings. The activity was not shown with 2,6-D and 2,4,6-T which are non-active as herbicides. The stimulation was not observed when NADPH was replaced with NADH or ascorbate. It is suggested that the increasing of dark lipid peroxidation in microsomes plays some role in the toxicity of the herbicides to plants.