Fig. 4
Albugo infection changes the proportions of camalexin and indolic glucosinolates but does not eliminate them. a and b Albugo infection changes expression of selected genes in the tryptophan-derived metabolite pathway upon P. infestans infection. Open circles and bars denote the mean ± SE of target gene expression (log2 transformed normalized relative quantities) in water-sprayed or AlNc14-infected tissue after water or P. infestans (100 μL of 1.25 × 105 spores per mL) inoculation. a 10 days post inoculation (dpi) with water or AlNc14, 6 hours post inoculation (hpi) with water or P. infestans. b 12 dpi with water or AlNc14, 48 hpi with water or P. infestans. Data are three independent biological replicates with two technical replicates each. Closed, black circles denote individual data points. Different letters indicate significant differences (P < 0.05) (Two-way ANOVA with Tukey’s honest significance difference). c Albugo and P. infestans infection triggers camalexin accumulation. High-performance liquid chromatography (HPLC) analysis of water-sprayed or AlNc14-infected Col-0 tissue (12 dpi), 48 hours post water or P. infestans inoculation (100 μL of 2.75 × 105 spores per mL). Open circles and bars denote the mean camalexin content per mg fresh weight ± SE of three independent biological replicates with six technical replicates each. Closed, black circles denote individual data points. Asterisks indicate significant differences from mock-treated plants (12 dpi water, 48 hpi water). Generalized linear model (GLM) with *P < 0.001. d Albugo infection decreases I3M levels but does not affect 4MO-I3M levels. HPLC analysis of mock or AlNc14-infected Col-0 tissue (12 dpi), 20 hpi mock or P. infestans (100 μL of 3 × 105 spores per mL). Open circles and bars denote the mean indolic glucosinolate content per g of fresh weight ± SE of five independent biological replicates with six technical replicates each. Closed, black circles denote individual data points. GLM with different letters indicating significant differences (P < 0.001)