The reactive oxygen species (ROS) level was studied in the Arabidopsis suspension cell cultures treated
with inhibitors of different respiratory complexes. The increase of ROS level upon the inhibition of electron transfer
through complexes III and IV was shown. At the same time, the inhibition of complex I activity led to the decrease
of ROS level. Moreover, the decreased ROS level was also detected in the cells of mutant Arabidopsis line with impaired
functioning of complex I. Thus, the complex I dysfunction in plant mitochondria is accompanied with significant
ROS decrease, which clearly differs plant cells from its animal counterpart.