Figure 4: Expression profiling of cold (4 °C)-regulated differentially expressed genes (DEGs) in S. album.

(a) Venn diagrams represent the overlaps of induced (left) and repressed (right) genes across three comparisons. (b) Induced and repressed genes for each pairwise comparison. (c) Heat map of the expression profiles of 4424 DEGs after cold stress. (d) Hierarchical clustering of DEGs in clusters in Fig. 3(c). The X axis represents time points of cold treatments. The Y axis represents the value of the relative expression level (log2 (FPKM + 1))(Fragments Per Kilobase of transcript per Million mapped reads). Hierarchical clustering was performed for DEGs with a ≥2-fold change and deviation probability ≥0.8 in at least one pairwise comparison of 0 vs 12 h/24 h/48 h using the Manhattan distance matrix of the heatmap.2 function in the gplots package of the R environment.