Figure 6.

SA interactions with jasmonates on AoPR10-GUS expression in transgenic tobacco and the generation of oxidative stress. AoPR10-GUS activity in explants of transgenic tobacco at 24 (A) and 72 h (B) following treatment with water (0) or 10, 100, or 250 μm SA with either 0, 10, 100, or 250 μm JA or at 24 h with 0, 10, 100, or 250 μm α-LN (C). D, AoPR10-GUS activity in tobacco leaves at 24 h following injection of water; 100 μm JA alone or a combination of 100 μm SA + 100 μm JA and also100 μm JA with 50 units mL⁻¹ catalase (CAT) or 100 μm SA + 100 μm JA with CAT. E, Changes in the conductivity (electrolyte leakage) of solutions bathing tobacco explants (1-cm diameter cores) from leaf panels previously inoculated with water and 50 units mL⁻¹ CAT or 250 μm JA + 250 μm SA with or without and 50 units mL⁻¹ CAT. Results are given as mean (n = 6) conductivity change, μS cm². F, H₂O₂ content in one third of tobacco leaves at 12 h following injection either with water (0), 100 μm JA, 100 μm SA, or 100 μm JA + 100 μm SA compared to another third of the leaf inoculated where 50 units mL⁻¹ CAT was added to either water (0), 100 μm JA, 100 μm SA, or 100 μm JA + 100 μm SA. For each sample the H₂O₂ content of the untreated third of the same leaf was subtracted from the value obtained for the treated parts. Results are given as mean (n = 6) samples H₂O₂ content (pmol g⁻¹ fwt) ± se.