Figure 2.

Effectiveness and responsiveness of inducible defences against H. arabidopsidis in nrpe1, ros1 and Col‐0.

(a) Effectiveness of callose deposition against Hpa infection at 48 h after inoculation of 3‐week‐old plants (10⁵ conidiospores ml⁻¹). Defence phenotypes were determined by epifluorescence microscopy in at least 10 leaves per genotype, and assigned to two different classes based on presence or absence of successful penetration into the mesophyll by Hpa. Inserts on the right show an example of each class. Germinating Hpa spores appear in blue (calcofluor white‐stained) and callose deposition is indicated by the presence of yellow staining (analine blue‐stained). Asterisks indicate statistically significant differences in class distributions compared to Col‐0 (χ² test; P < 0.05). Scale bars = 100 μm.

(b) RT‐qPCR quantification of PR1 gene expression in Col‐0, nrpe1 and ros1 at 48 and 72 h after inoculation with Hpa or mock treatment. Data represent mean values of relative expression (±SEM) from four biologically replicated samples. Asterisks indicate statistically significant differences in comparison to Col‐0 (Student's t‐test; P < 0.05).