Figure 8

Resistance to B. cinerea and ROS production in waxless myb96KO mutants. (A) Resistance to B. cinerea in myb96-1 mutant and wild type Col0 plants. Four representative pictures of necrosis due to B. cinerea are illustrated above each histogram. After B. cinerea inoculation, all plants were kept under humid conditions (n = 128; ±SE). The experiment was repeated twice with similar results. Asterisks indicate statistically significant differences between Col0 and myb96-1 mutant, T-Test (p < 0,01). (B) Quantification of ROS production at 3, 6, 10 h after inoculation with B. cinerea (Bc) or mock treatment in myb96-1 mutants compared to Col0. After treatment, all plants were kept under humid conditions (n = 6; ±SD). Asterisks indicate statistically significant differences between Col0 and myb96-1 mutant after B. cinerea inoculation or mock treatment, T-Test (p < 0,01). (C) Permeability of the cuticle in WT Col0 leaves compared to myb96-1 mutant. Leaves were placed in ethanol and the release of chlorophyll was followed over time (n = 3; ±SD). The experiment was carried out 3 times, one typical result is represented. (D) Permeability of the cuticle as determined by the toluidine blue test. The blue stain that remains attached to the cell wall is indicative of a permeable cuticle. The percentage of droplets stained in blue relative to the total inoculated droplets was calculated (n = 3; 90 droplets per experiment; ±SD). Two representative pictures of leaves stained with toluidine blue were placed above each histogram as a visual illustration. Asterisks indicate statistically significant differences between Col0 and myb96-1 mutant, T-Test (p < 0,01). (E) Permeability of the cuticle as determined after Calcofluor white staining and viewing under UV light. Calcofluor retention by the cellulose is indicative of a permeabilized cuticle (the experiment was carried out 3 times, one typical result is represented).