Effects of DC3000 pathogens and red light alone or in combination on the glutathione content, and GSH/GSSG ratio in leaves of tomato plants at 19 h post-inoculation. The plants were kept in the dark (open column) or under red light (grey column) conditions at night without (Mock) or with the immediate inoculation of DC3000. Data are the mean ± SD of five biological replicates. Means denoted by the same letter did not differ significantly at p < 0.05 according to Duncan’s multiple range test. The experiments were repeated twice with similar results.