|SLAUGHTER, LINDSEY - University Of Kentucky
|NELSON, JIM - University Of Kentucky
|CARLISLE, ELIZABETH - University Of Kentucky
|BOURGUIGNON, MARIE - Iowa State University
|PHILLIPS, TIMOTHY - University Of Kentucky
|MCCULLEY, REBECCA - University Of Kentucky
Submitted to: Fungal Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/6/2017
Publication Date: 1/9/2018
Citation: Slaughter, L.C., Nelson, J.A., Carlisle, E., Bourguignon, M., Dinkins, R.D., Phillips, T.D., McCulley, R.L. 2018. Climate change and Epichloë coenophiala association modify belowground fungal symbioses of tall fescue host. Fungal Ecology. 31:37-46.
Interpretive Summary: Manipulation of the genetic variability among endophytic E. coenophiala strains within tall fescue (Schedonorus arundinaceus) has led to widespread deployment of non-toxic grass-endophyte combinations, yet little is known about their ecological consequences. We investigated how tall fescue common toxic and non-toxic endophyte associations impacted belowground fungal symbioses and whether these relationships were sensitive to different environmental conditions. Soil and root samples were collected from two clones of tall fescue, one with and without a common toxic endophyte and one with and without a non-toxic endophyte. These were evaluated in control plots under ambient conditions, plots that received additional precipitation (plus 30% of the long-term annual mean), in plots with increased temperatures (+3°C) and plots with the combination of increased temperature and increased precipitation after two years under the above conditions. Root arbuscular mycorrhizal fungi and extraradial hyphea and dark septate endophyte colonization was measured for each of five replications. Root arbuscular mycorrhizal fungi arbuscules, vesicles, and extraradical hyphae length were affected by tall fescue genotype but not specifically by the presence or absence of the endophyte whereas dark septate endophyte colonization was reduced by E. coenophiala presence, but stimulated by warming. In conclusion, genetically distinct tall fescue-E. Coenophiala associations may have distinct long-term impacts on other symbiont interactions and belowground communities under different environmental conditions.
Technical Abstract: Human alteration of symbiont genetics among aboveground endophytic Epichloë coenophiala strains within tall fescue (Schedonorus arundinaceus) has led to widespread deployment of novel grass-endophyte combinations, yet little is known about their ecological consequences. In this study, clone pairs (endophyte-infected, endophyte-free) of two tall fescue genotypes received factorial combinations of increased temperature (+3°C) and precipitation (+30% long-term annual mean) for two years. We measured root arbuscular mycorrhizal fungi (AMF) and dark septate endophyte (DSE) colonization and soil AMF extraradical hyphae (ERH) length. We hypothesized that genetically distinct grass-E. Coenophiala associations would differentially affect belowground fungi, and that these relationships would be climate-sensitive. Tall fescue genotype, endophyte presence, and climate treatments interactively affected AMF arbuscules, vesicles, and ERH. DSE decreased with E. coenophiala presence but increased with warming. Genetically distinct tall fescue-E. Coenophiala associations may have divergent long-term impacts on other host-symbiont interactions, potentially impacting ecosystem function and response to climate change.