Abstract Detail

Ecology/Pathology

Wright, Chris [1], Paul, E. A. [2], Reddy, C. A. [3], Tiedje, J. M. [4], Trail, F. [1], Schmidt, T. M. [5].

Species Richness and Lignolytic Potential of Decomposer Fungi Inhabiting Midwest Agricultural Soils.

Decomposer soil fungi provide many essential ecosystem services, including the deconstruction of lignin, a stereo-complex component of lignocellulose that confers resistance to decay.  The deconstruction of lignin is essential for the release of minerals and nutrients bound in woody plant litter, and is the rate-limiting step in the global C cycle.  Here, we examined how select agricultural land management practices impacted the community structure and genetic potential for lignolytic activity of the decomposer fungi living in those soils.  Soil communities inhabiting till vs. no till agriculture treatments were compared to the community inhabiting the soil of a nearby deciduous forest (the native terrestrial ecosystem from which the agronomic treatments evolved), as well as the soil community of a mid-successional treatment that was historically under agronomic management, but abandoned 23 years prior to this study. We found that although agricultural practices did not have a dramatic impact on the absolute species richness of soil fungi, it did impact how those communities were structured in terms of membership. NMDS scaling analyses based on pairwise comparisons of 28S OTU profiles of treatment replicates revealed a distinct fungal OTU composition in each treatment. Using the Jaccard index to compare the similarity of the treatments, the replicate samples from the traditionally tilled corn/wheat/soybean treatment, the no-till corn/wheat/soybean treatment, the mid-successional treatment and the native deciduous forest clustered together by treatment. One-way analysis of similarities (ANOSIM) indicated the differences were statistically significant (p<0.05).  Saprotrophic members of the soil fungal community were richer in terms of numbers of species than any other ecological group.  Mycorrhizal species were second in terms of richness.  Phylogenetically, Basidiomycota were highest in terms of numbers of species, outnumbering all other discovered phyla, which included the Ascomycota, Chytridiomycota, Glomeromycota, Blastocladiomycota and Neocallimastigomycota. Similarly, although land management practices did not significantly alter the total number of lignolytic genes detected from each treatment, it did alter the occurrence of specific genes detected in each treatment. NMDS scaling analyses based on the FUNCHIP profiles of samples from each treatment indicated a distinct lignolytic gene composition in the communities from each site; replicate samples all clustered together by treatment. ANOSIM indicated the differences were statistically significant (p<0.05).

1 - Michigan State University, Plant, Soil and Microbial Sciences, Plant Biology Building, East Lansing, MI, 48824, USA
2 - Colorado State University, Natural Resource Ecology Laboratory
3 - Michigan State University, Microbiology and Molecular Genetics
4 - Michigan State University, Center for Microbial Ecology
5 - University of Michigan, Ecology and Evolutionary Biology

Keywords:
Lignolytic Fungi
Metagenomics
soil fungi.

Presentation Type: Offered Paper - Paper
Session: 7
Location: Auditorium/Kellogg Hotel and Conference Center
Date: Tuesday, June 10th, 2014
Time: 9:15 AM
Number: 7004
Abstract ID:202
Candidate for Awards:None