Fig. 4: Changes in Fe-associated gene abundance by soil layer during extended thaw incubation.

Relative abundance (mean % ± SD) of iron (Fe)-related gene pathways including (A) Fe regulation, (B) Fe storage, (C) Fe transport, (D) siderophore transport, (E) Fe(III) reduction, and (F) Fe(II) oxidation derived from the active layer, transition zone, and permafrost metagenomes. Significant differences were determined between incubation time points within each soil layer microbiome (ANOVA; ***p < 0.001, **p < 0.01, *p < 0.05).