Fig. 5: Amino acid degradation and nitrate reduction during snowmelt.
From: Multi-omics reveals nitrogen dynamics associated with soil microbial blooms during snowmelt
a, Small-molecule metabolites detected by 1H-NMR. Filled symbols indicate metabolites detected in Stickland-like oxidation reactions. Metabolites were categorized as ‘higher before snowmelt’ (March higher relative September or May concentration; dark blue circles), ‘highest during snowmelt’ (May higher relative to June or March; light blue circles) or ‘higher after snowmelt’ (June higher relative to May concentration; red circles). Data were combined across soil depths. Unfilled circles (compounds) were not detected in our dataset. Text in italics are genes in the pathway (see Extended Data Fig. 7 for gene expression). Expressed genes in the pathway are: ilvE, branched-chain aminotransferase; ilvA, tcdB, threonine dehydratase; ldh, lactate dehydrogenase; pflD, pyruvate-formate lysase; vorA, 2-oxoisovalerate ferredoxin oxidoreductase alpha subunit; pta, phosphate acetyltransferase; ackA, acetate kinase. b, Gene expression for nitrate/nitrite consumption through denitrification or respiratory dissimilatory nitrate reduction to ammonia (DNRA) had their highest expression before or during snowmelt (see Extended Data Fig. 8). Numbers in parentheses indicates the magnitude of increase (%) in gene expression ranging across soil depths. c, Metabolic reconstruction of winter-adapted Bradyrhizobium spp. MAGs [Bins 167, 164] that showed high total gene expression both during winter and snowmelt. Winter-adapted Bradyrhizobium spp. had the highest gene expression for branched-chain amino acid fermentation and the ability to consume N2O during snowmelt (see Supplementary Table 6 for full gene expression data). Dashed arrows represent gene expression of processes not observed in our data set. Figure created with BioRender.com (https://BioRender.com/48mpj37, https://BioRender.com/nowv87a, https://BioRender.com/wlixzrn).
