FIGURE 1.

Systemic ROS generation is induced after root inoculation with B. japonicum. Leaves of non-inoculated (control, C) and inoculated (I) plants were sampled at different times after root inoculation (nd represent times not determined), and incubated with (A) 3,3′-diaminobenzidine (DAB) or (B) NBT for H₂O₂ and O₂^- staining, respectively. The pictures of the stained leaves were transformed into 8-bit images and the gray value intensity (O.D.) was quantified by image processing software. Results are the means of three independent experiments (four leaves per treatment). Data are means ± SE. Asterisks indicate significant difference between control and inoculated treatments (p < 0.05, Tukey test). (C) H₂O₂ quantification by spectrofluorometer. The results are the means of three independent experiments (six leaves per treatment). Data are means ± SE. Asterisks indicate significant difference between control and inoculated treatments (p < 0.05, Tukey test).