Fungal functional gene composition
A total of 2,590 probes of 82 fungal functional genes responsible for
nutrient cycling, stress, energy processes, and virulence were detected.
In line with our first hypothesis, we found that warming altered the
overall functional gene composition significantly (Table 1, P< 0.05), which was further verified by the PCoA plot (Fig.
S2b). Therefore, we performed the SIMPER analysis to identify major
functional genes responsible for the differences. A total of 12
functional genes had significant contributions (Table 2, P< 0.05), which were associated with C degradation (i.e., genes
encoding cellobiase, xylanase, glyoxal oxidase, metalloprotease,
phospholipase A2, vanillin dehydrogenase, xylose reductase, invertase),
S cycling (i.e., genes encoding sulfate transporter and PAPS reductase),
P utilization (i.e., the gene encoding phytase) and stress tolerance
(i.e., the gene encoding superoxide dismutase).
In
line with our second hypothesis, 3 out of a total of 53 fungal C
degradation genes showed significantly (P < 0.05)
higher relative abundances under warming , which encode invertase for
sucrose degradation (increased by 16.7%), xylose reductase for
hemicellulose degradation (increased by 231.62%), and vanillin
dehydrogenase for lignin-derived aromatics degradation (increased by
47.64%) (Fig. 1). The gene encoding phytase for P utilization was also
significantly increased by 11.37% (P < 0.05).
Additionally, a total of 30 oligonucleotide probes of C degradation
genes were only detected in warmed samples (Table S2).