Abstract Detail

Ecology/Pathology

David, Aaron [1], May, Georgiana [1], Seabloom , Eric [1].

Disentangling drivers of root endophyte communities in beach grasses.

Endophytic fungi inhabit all plant species and represent a large portion of undiscovered fungal diversity. Despite their ubiquity, relatively little is known about their ecology and, in particular, how they assemble into communities inside their hosts. Communities are likely influenced by a combination of four factors: environment, host species, interactions among endophytes, and dispersal. To better understand the relative importance of these factors, we conducted a field experiment focusing on root endophyte communities in beach grasses along the USA Northwest Coast. We collected tillers of three grass species (Elymus mollis, Ammophila arenaria, A. breviligulata) with preexisting root endophyte communities from the environmentally-distinct foredune and backdune, and reciprocally transplanted them into control or host-removal plots designed to reduce endophyte dispersal from nearby roots. Endophytes from experimental tillers were cultured from roots before and after the experiment, and classified into operational taxonomic units based on sequencing of ITS1 and ITS2. We found that transplants to the backdune had higher infection frequencies, indicating a strong role of environment in affecting endophyte abundance. Endophyte communities were dependent on the interaction between the source of tillers and the environment into which they were transplanted. The host-removal treatment did not affect overall infection frequency or community structure, but did increase the presence of the most common OTU, a fast-growing Microdochium, suggesting that this OTU might have relatively low dispersal limitation. We conclude that environment is likely the most important factor in root endophyte assembly, but that interactions with previously established endophytes and dispersal also play important roles. Though community assembly is complex, root endophytes may in some cases follow predictable patterns. Disentangling the factors affecting endophyte communities ultimately contributes to a clearer understanding of their immense diversity.

1 - University of Minnesota, Ecology, Evolution, and Behavior, 1987 Upper Buford Cir, Saint Paul, Minnesota, 55108, United States

Keywords:
root endophyte
community assembly
dispersal
dune
beachgrass.

Presentation Type: Offered Paper - Paper
Session: 5
Location: Room 103 AB/Kellogg Hotel and Conference Center
Date: Monday, June 9th, 2014
Time: 1:00 PM
Number: 5001
Abstract ID:37
Candidate for Awards:Graduate Student Oral Presentation Award