Reactive oxygen species and depolarization the inner mitochondrial membrane under effect of synthetic auxin herbicides in plant cell culture of Arabidopsis thaliana L.

The cytotoxic effect of synthetic analogs of auxins, namely 2.4-D and clopyralid on heterotrophic cell suspension culture of Arabidopsis thaliana, was studied. The dynamics of cell death in A. thaliana in the culture as well as changes in the reactive oxygen species (ROS) level in cells and in the electrochemical transmembrane potential on the inner mitochondrial membrane (ΔΨm) were studied by means of FDA and PI, H₂DCF-DA and JC-1 fluorescent probes. According to the results obtained, the rate of cell death in A. thaliana treated with synthetic auxin herbicides 2.4-D and clopyralid depends on the active substance dose. In this case, the toxic effect of synthetic auxins is not due to the development of oxidative stress in cells but is most likely associated with the depolarizing effect of these agents on the inner mitochondrial membrane.