Dependence of endophytic fungus – grass symbioses on land-use intensity

Endophytic fungi in cool-season grass species (Poaceae) produce herbivore-toxic alkaloids which can affect species communities and ecosystem functioning. These alkaloids can be toxic for vertebrate (e.g. cattle, sheep, horses) and invertebrate herbivores, depending on the concentration and composition of produced alkaloids. If infection rates of grass species and alkaloid production depend on land-use intensity is not well known. Similarly, the effects of different species of endophytic fungus and host grass species on herbivory rates and herbivore diversity is unknown.

Background

In this project we like to quantify the infection rates (occurrence and abundance) and alkaloid concentrations of Poaceae species in the 150 grassland EPs of the Biodiversity Exploratories.

We collected more than 600 grass samples of the perennial ryegrass Lolium perenne in 2014 and will detect the endophytic fungus Neotyphodium lolii using immunoplot assays and qPCR of genomic DNA. We will also quantify the alkaloids using an UPLC-Tandem-MS. We also plan to sample other Poacea species, which occur in reasonable abundances in the exploratory grasslands to identify possible infections of the Neotyphodium/Epichloë species group and to detect their alkaloid profiles. In a last subproject we will collect again samples of Lolium perenne on the grasslands and will use barcoding techniques to detect the endophyte diversity.

Hypotheses

With our data we like to address the following key research questions focusing on the diversity of endophytic fungus – host grass symbiosis and ecosystem functioning of infected host grass:

1. Which endophytic fungus – grass symbioses are present in grasslands and are they affected by land-use intensity?

2. Are alkaloid profiles and concentrations produced by endophyte-grass symbioses in the Biodiversity Exploratories toxic for herbivores?

Publications

Infection Rates and Alkaloid Patterns of Different Grass Species with Systemic Epichloë Endophytes

Infektionsraten und Alkaloidmuster verschiedener Grasarten mit systemischen Epichloë Endophyten

Vikuk V., Young C. A., Lee S. T., Nagabhyru P., Krischke M., Müller M. J., Krauss J. (2019): Infection Rates and Alkaloid Patterns of Different Grass Species with Systemic Epichloë Endophytes. Applies and Environmental Microbiology 85 (17), e00465-19. doi: 10.1128/AEM.00465-19

Hide and seek – Infection rates and alkaloid concentrations of Epichloë festucae var. lolii in Lolium perenne along a land-use gradient in Germany

König J., Fuchs B., Krischke M., Mueller M. J., Krauss J. (2018): Hide and seek – Infection rates and alkaloid concentrations of Epichloë festucae var. lolii in Lolium perenne along a land-use gradient in Germany. Grass and Forage Science 73 (2), 510-516. doi: 10.1111/gfs.12330

Knowing your neighbourhood—the effects of Epichloë endophytes on foliar fungal assemblages in perennial ryegrass in dependence of season and land-use intensity

König J., Guerreiro M. A., Peršoh D., Begerow D., Krauss J. (2018): Knowing your neighbourhood—the effects of Epichloë endophytes on foliar fungal assemblages in perennial ryegrass in dependence of season and land-use intensity. PeerJ 6:e4660. doi: 10.7717/peerj.4660

Fungal grass endophytes and their dependence on land-use intensity

Gras-Endophyten und ihre Abhängigkeit von der Landnutzungsintensität

König J. (2018): Fungal grass endophytes and their dependence on land-use intensity. Dissertation, University of Würzburg.