Fig. 2: Polyphenol transformations expressed in Stordalen Mire.

a, Hierarchical clustering of the relative metatranscriptome expression of polyphenol transformations across habitats and depths (rows: S, surface; M, middle; D, deep depths). Here, relative metatranscriptome expression is displayed as the z-score of the average of the summed expression (n = 3, geTMM) of genes in each pathway (columns). The saturation column to the right of the heat map denotes samples as saturated (red) if they were at or below the water table depth, or unsaturated (white) if they were above the water table (Supplementary Data 1 and Fig. 2). Hierarchical clustering of pathways revealed palsa (brown), bog (green) and fen (blue) specific transformations, indicated by top-row colour. The oxygen requirements for transformations are shown in the second bottom-most row for oxic (blue) and anoxic (red) transformations. The family of polyphenols that each pathway acts upon is coloured at the bottom-most row: black (polymers), pink shades (monomers) and orange shades (phenolic/benzoic acids). Column numbers correspond to transformations; see Supplementary Data 2 for more detail on each transformation. Transformations mentioned in the text are enclosed in a black box, and the numbers are highlighted black in the heat map to match the text reference, and the reactions are shown in b–e. Arrow colours correspond to the habitat cluster for the transformation: palsa (brown), bog (green) and fen (blue). In no. 39, the wavy arrow indicates that the hydroxyl radical diffuses away to act on phenolic polymers. All pathways are shown in Supplementary Fig. 6.