Fig. 2.

Effects of stress treatments on total microsomal and soluble guaiacol peroxidase activities from 5-d-old maize roots. Maize seedlings were exposed to different stressors as indicated. Each treatment was analysed using 2–3 independent experiments. Total class III peroxidase activities were determined in triplicate in each experiment. Relative peroxidase activities were calculated in comparison with direct controls that were handled in parallel. Shown are means ±SE (n=6–9; controls n=30). Class III peroxidase activities were measured in the presence of 8.26 mM guaiacol and 8.8 mM H₂O₂. Values that were significantly different from the controls in t test analysis were marked at P < 0.001 (*) and P < 0.05 (**). H₂O₂ (2 mM); wounding (cutting); methyl-jasmonate (50 μM); salicylic acid (0.5 mM); F. graminearum extract (250 ng protein ml⁻¹); F. culmorum extract (125 ng protein ml⁻¹); chitosan (20 μg ml⁻¹); cantharidin (20 μM); FW, fresh weight. For treatment times see Table 2. (Soluble enzymes, grey bars; membrane-bound enzymes (microsomes), dotted bars.