Abstract Detail

Poster Session

Morgan, Benjamin [1], Egerton-Warburton, Louise [1].

High-throughput sequencing reveals diverse fungal communities associated with lignin decomposition in seasonally dry forests of the Yucatan Peninsula.

Plant litter decomposition is a critical step in the formation of soil organic matter, the mineralization of organic nutrients, and the carbon balance in terrestrial ecosystems. Decomposition is generally negatively correlated with the concentration of lignin, a group of complex aromatic polymers present in plant cell walls that is recalcitrant to degradation, and can only be modified by enzymes produced by white-rot fungi primarily in the Basidiomycota. However, little is known about the composition of in situ fungal communities associated with lignin degradation, and studies to date have largely examined communities in temperate and boreal systems. This project examined the diversity and gene products of a tropical lignin degrading community to identify keystone species and their functions. Our focus is the dry seasonal tropical forest where the turnover of plant litter is rapid, and microbial diversity is immense but largely unexplored. We selected for lignin decomposing communities by placing in situ traps with lignin alkali medium at a minimally managed forest site in the Yucatan Peninsula for five months during the wet season, and surveyed taxonomic and functional genetic diversity using high-throughput ITS and metagenome sequencing on Illumina platforms. ITS sequencing identified highly diverse decomposer communities, with 200-2000 OTUs per sample, spanning nearly 300 genera. Most samples were dominated by Basidiomycota, including well-known lignin degrading fungi such as Geastrum species and taxa in the Polyporaceae. However, we also observed ectomycorrhizal taxa including Russula and Suillus species, as well as a large diversity of Ascomycota. These results suggest that rapid, complete decomposition of lignocellulose in nature requires complex species assemblages. Further analyses of metagenomic data will identify potential combinations of gene products that contribute to decomposition.

1 - Chicago Botanic Gardens, Plant Science and Conservation, 1000 Lake Cook Rd, Glencoe, IL, 60022, United States

Keywords:
guild decomposition
dry seasonal tropical forest
lignocellulose
Metagenomics
Fungal barcoding 
Environmental sequencing
NGS (next-generation sequencing).

Presentation Type: Offered Paper - Poster
Session: P4
Location: Lincoln Room/Kellogg Hotel and Conference Center
Date: Tuesday, June 10th, 2014
Time: 8:00 PM
Number: P4004
Abstract ID:198
Candidate for Awards:Graduate Student Poster Presentation Award