Figure 4.

Weighted Correlation Network Analysis (WGCNA) of GC-MS metabolic profiles of the Synechocystis during butanol tolerance improvement. A) Experiment I; B) Experiment II. The distinct modules identified at each time point were indicted by the clustering patterns of the red color squares along the diagonal inside the plots. The modules highly associated with any given butanol stress (r > 0.5 and p-value <0.05) were identified and indicated by the color bar shown along the left side and at the top, where one color represents one distinct module. The metabolites associated with each of the distinct module were listed beside the plots with their module number indicated. The correlation coefficients and p-values were shown in the Tables 1 and 2.