FIGURE 8.

Assessment of direct effect of PE on the early steps of P. viticola infection in planta. Plants were treated with 5 g L⁻¹ PE, or equal volumes of conserving agents or water, and were inoculated with P. viticola sporangia suspension (10⁵ sporangia mL⁻¹) at 2 hpt. Aniline blue staining was performed to visualize: (A) the number of infection sites per observation field, counted at 24 hpi; and (B) the hyphal colonization surface (%) per observation field at 48 hpi, estimated by image analysis. Results correspond to the mean ± standard deviation of three independent biological repetitions. Significant differences (p ≤ 0.05) were identified with Kruskal–Wallis coupled with Dunn’s multiple comparison test. Conditions with different letters are significantly different. Pictures presented hereby are the ones with the closest values to the mean. Scale bars represent 100 μm.