Fig. 4.

Heatmap of Brassica napus genes differentially expressed following inoculation by Leptosphaeria maculans and Leptosphaeria biglobosa. RNA samples were collected at 2, 4, 7, 9, 11, and 15 days post-inoculation (dpi) following inoculation of Brassica napus cv. Darmor-bzh cotyledons. Single-species inoculations (SSI) were done by inoculating pycnidiospore suspensions of Leptosphaeria maculans “brassicae” (Lmb) or Leptosphaeria biglobosa “brassicae” (Lbb) at 10⁷ pycnidiospores.mL⁻¹ and mixed species inoculations (MSI) were done by mixing an equal volume of Lmb and Lbb spore suspensions at 10⁷ pycnidiospores.mL⁻¹. a The total number of differentially expressed genes (DEGs) was obtained according to two statistical comparisons: for each of the six sampled timepoints, (i) gene expression in cotyledons inoculated with Lbb (SSI and the MSI) was compared to that of the control cotyledons inoculated with water and (ii) gene expression in cotyledons inoculated by Lmb was compared to that of control cotyledons inoculated with water. From these differentially expressed gene sets, the Venn diagram illustrates the intersection of the up- or downregulated genes in response to Lmb SSI (1,6); in response to “Lbb SSI + MSI” (3, 4), and in response to both Lmb SSI and “Lbb SSI + MSI” (2,5). b The heatmap represents the normalized expression (centered Log₂(FPKM + 1)) of DEGs in B. napus following mock inoculation with water (left block), and during SSI by Lmb or Lbb (middle and right blocks, respectively). Genes were grouped in the six categories highlighted by the Venn diagram, and identified by the bar on the left of the heatmap with the same color code as in the Venn diagram