Talbot, J. M. et al., 2015. Soil Biology & Biochemistry

Functional guild classification predicts the enzymatic role of fungi in litter and soil biogeochemistry

Jennifer M. Talbot, Francis Martin, Annegret Kohler, Bernard Henrissat, and Kabir G. Peay
21 May 2015, Soil Biology & Biochemistry 88 (2015): 441-456; doi: 10.1016/j.soilbio.2015.006

Abstract

Linking community composition to ecosystem function is a challenge in complex microbial communities. We tested the hypothesis that key biological features of fungi – evolutionary history, functional guild, and abundance of functional genes e can predict the biogeochemical activity of fungal species during decay. We measured the activity of 10 different enzymes produced by 48 model fungal species on leaf litter in laboratory microcosms. Taxa included closely related species with different ecologies (i.e. species in different “functional guilds”) and species with publicly available genomes. Decomposition capabilities differed less among phylogenetic lineages of fungi than among different functional guilds. Activity of carbohydrases and acid phosphatase was significantly higher in litter colonized by saprotrophs compared to ectomycorrhizal species. By contrast, oxidoreductase activities per unit fungal biomass were statistically similar across functional guilds, with white rot fungi having highest polyphenol oxidase activity and ectomycorrhizal fungi having highest peroxidase activity. On the ecosystem level, polyphenol oxidase activity in soil correlated with the abundance of white rot fungi, while soil peroxidase activity correlated with the abundance of ectomycorrhizal fungi in soil. Copy numbers of genes coding for different enzymes
explained the activity of some carbohydrases and polyphenol oxidase produced by fungi in culture, but were not significantly better predictors of activity than specific functional guild. Collectively, our data suggest that quantifying the specific functional guilds of fungi in soil, potentially through environmental sequencing approaches, allows us to predict activity of enzymes that drive soil biogeochemical cycles.

Highlights

  • We tested which biological features of fungi predict their enzyme activities.
  • Functional guild (saprotrophs vs. ectomycorrhizal) best predicted enzyme activity.
  • Functional gene abundance predicted functional guild of fungi.
  • Ectomycorrhizal fungi produced peroxidase activity equal to white rots.
  • Functional guilds predicted enzyme activities in field soil across the U.S.

Citation

Talbot JM, Martin F, Kohler A, Henrissat B, and Peay KG. 2015. Functional guild classification predicts the enzymatic role of fungi in liter and soil biogeochemistry. Soil Biology & Biochemistry 88: 441- 456
doi: 10.1013/j.soilbio.2015.05.006