Fig. 5: Agroinfiltration of Nicotiana benthamiana with Ve results in increased levels of reactive oxygen species (ROS).

The photographs show N. benthamiana plants after infection with Verticillium dahliae (DSM 11938). No (a) or strong symptoms (b, c) were visible in the untreated (a) or spore treated (b, c) control leaves. The heterologous expression of Ve1Myc (d), Ve2FLAG (e) or the combination of the tagged receptors (f) was induced prior to infection, the infection symptoms appeared to be mild, especially in combination (f). Production of ROS triggered by signal perception (g–l). Graphs showing the rise of luminescence with V. dahliae elicitor in an HRP/luminol leaf disc assay that is associated with the formation of oxidative burst (n = 3 for each construct). In the control leaves with and without elicitor the formation of an oxidative burst is absent (g–i). The heterologous expression of Ve1Myc (j) and Ve2FLAG (k) in N. benthamiana leaves enable an oxidative burst that is elicited by V. dahliae (DSM 11938) culture. If both receptors Ve1 and Ve2 are expressed simultaneously (l), the recorded luminescence change significantly (p < 0.01) exceeds the values that were measured in the single infiltrations. The recorded maximum difference in luminescence with spore suspension and with no spores (ΔLmax) changed significantly. The values in (m) display ΔLmax and are marked with different letters for significant different values (p < 0.01).