Figure 5.

Light microscopy images of peroxidase (POD) and polyphenol oxidase (PPO) activity in leaf discs of Zantedeschia aethiopica treated with plant activators: distilled deionized water (ddw) (control), 5 μg/mL benzothiadiazole (BTH) or 10 mg/mL methyl jasmonate (MJ). The discs were inoculated with Pectobacterium carotovorum 24 h later. Enzymatic activity was recorded 24 h after inoculation following incubation with diaminobenzidine (DAB) for the localization of POD activity (a) and dopa for the localization of PPO activity (b). POD or PPO activity was visualized via the accumulation of a polymerized product, as shown by the brown/black ring around the wounded or infected site (bar, 500 μm).