The Role of Plant Fungal Endosymbionts in Rhizosphere Priming.

Tall fescue (Lolium arundinaceum (Schreb.) is a cool-season perennial grass within which can live a fungal endophyte (Epichloë coenophiala) thought to provide enhanced edaphic and climactic stress tolerance to the host compared to non-infected individuals.  Our prior research demonstrated that a variety of root exudate compounds released from tall fescue were differentially affected by tall fescue cultivar, endophyte genotype and their interaction. Changes in root exudates could directly influence or mediate key soil biogeochemical processes including carbon, nitrogen and phosphorus cycling, but these effects may differ depending on fescue and endophyte genetics.  This presentation will review the effects of this plant-endosymbiont interaction on soil microbial community structure (PLFA and NGS) and function (enzyme assays, respiration) and how it influenced soil organic matter associated C and N (POM, n-POM, DOC, DON, etc.) fractions and P speciation in rhizosphere and bulk soils from both field and glasshouse studies.