Abstract Detail

Mycological Section

Klymiuk, Ashley A. [1], Sikes, Benjamin A. [2].

Variability of fungal root endophyte communities in the aquatic macrophyte Typha.

Cataloguing microbial diversity of aquatic macrophytes is a burgeoning field of research, and all functional groups of terrestrial root endophytes are now known to be present in aquatic systems. In determining the ecological role(s) of these fungi, however, comparisons with terrestrial systems may be inappropriate: Not only are aquatic systems P- as opposed to N-limited, but intermittent or permanent inundation defines gradients in oxygen availability and reduction-oxidation potential. This fundamental change in chemistry (from oxidizing to reducing and aerobic to anaerobic) is unparalleled in fully terrestrial soils. We hypothesize that the structure and diversity of root endophyte communities will be principally defined by inundation depth, as root oxygenation is known to decline with depth, in spite of structural and physiological adaptations to aquatic habit. We predict that endophyte communities deepest within the inundation gradient will have low fungal diversity and/or greater phylogenetic clustering than endophyte communities occurring in plants highest along the inundation gradient. Typha root endophytes were assessed along inundation gradients in three Kansas catchment basins. Roots were excavated from 3 plants, for each of 5 sampling points per transect (i.e., n=15 plants per transect, 3 transects per basin). The mycobiomes of surface-sterilized Typha roots were assessed using traditional plate culturing (PDA and V8) and high-throughput sequencing (Illumina Mi-seq) of the 28S rDNA region, targeted with fungal specific primers (NL1-NL4). Parallel bioinformatic analyses were performed in multiple pipelines (USEARCH, Qiime, and mothur), which employ different native algorithms for similarity-based clustering of sequences as OTUs. We present the results of these analyses in a comparative framework, demonstrating the degree to which bioinformatic assumptions influence interpretations of fungal endophyte diversity. Diversity of both cultured and sequenced fungi were compared with multivariate techniques (NMDS, PCA, Indicator Species Analysis). To determine whether sequences within sites exhibit phylogenetic clustering or dispersion, we performed simultaneous phylogenetic alignment and tree estimation using SATé.

1 - University Of Kansas, Ecology & Evolutionary Biology, Rm 45Takeru Higuchi Hall, Kansas Biological Survey, 2101 Constant Ave, Lawrence, KS, 66047, USA
2 - University of Kansas, Ecology & Evolutionary Biology/Kansas Biological Survey, 2101 Constant Avenue, Takeru Higuchi Hall, Lawrence, KS, 66047, USA

Keywords:
fungal endophyte
reduction-oxidation
Aquatic plants
emergent vegetation
Metagenomics.

Presentation Type: Oral Paper:Papers for Sections
Session: 29
Location: Salon 1/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 8:15 AM
Number: 29002
Abstract ID:654
Candidate for Awards:None