Functional role of phyllosphere fungi in litter decomposition in response to land use

• Applicants: Professor Dr. Dominik Begerow; Privatdozent Dr. Derek Persoh
• Subject Area: Ecology and Biodiversity of Plants and Ecosystems ; Microbial Ecology and Applied Microbiology
• Term: from 2014 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 252027963

The European Beech (Fagus sylvatica) is one of the most important and best studied trees in Central Europe. As all trees, it hosts an immense diversity of endophytic fungi. However, community structure of endophytic fungi is poorly understood, mostly due to the multiplicity of environmental factors involved. Furthermore, the functional diversity and ecological role of endophytic fungi in ecosystem processes, such as carbon and nitrogen cycling, is all but clear. Recent studies, however, showed that a considerable fraction of the endophytic community is also present in litter and has the enzymatic capabilities to degrade dead plant material. Here, we strive for unravelling biogeographical patterns, seasonal dynamics and land-use-dependency of beech-endophyllous fungi, their role in leaf-litter degradation and the life cycles of fungi colonizing the two habitats (living and decaying leaves). In particular, we test the implications of the hypothesis that by promoting tree individuals with enhanced defence capabilities, silviculture favours the establishment of host or habitat adapted endophytic fungi, which decompose leaf-litter more efficiently than less adapted fungi, thus contributing more significantly to the nutrient cycles.The design of the biodiversity exploratories provides an invaluable prerequisite for unravelling such complex connections. In addition to the available environmental background data from collaborating groups, leaf physiology and biochemistry will be consistently monitored to provide the basis for conclusively discussing the assessed molecular data. Next Generation Sequencing (NGS) of DNA- and RNA-derived markers will assess seasonal dynamics in community structure and activity profiles of endophytic and leaf-litter degrading fungi against regional, environmental and land-use gradients represented by the exploratory design. Metatranscriptomes in leaf-litter will be also analysed by NGS, to identify decomposition enzyme coding genes actually expressed by the fungal community. The underlying processes and driving factors will be addressed in detail in laboratory experiments, in which the impact of temperature regimes and litter quality on gene expression profiles of different beech-leaf-endophytic fungi, will be assessed during decomposition. The project will provide an immense data pool, molecularly characterising beech-endophyllous and litter degrading fungal communities in the exploratories, in addition to the physiological and biochemical characterisation of the host plants. In particular the metatranscriptomic data have the potential to reveal patterns and initiate hypotheses far beyond the addressed hypotheses, especially by serving as a basis for modelling nutrient cycles and species interactions. Accordingly, the hypothesis-driven approach will be complemented by data-driven research, which we assume to have a major impact on future studies on ecosystem processes, not only in the biodiversity-exploratories.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1374: Biodiversity Exploratories