Mulot, Matthieu

2020-9-18, Reczuga, Monika, Seppey, Christophe Victor William, Mulot, Matthieu, Jassey, Vincent E.J., Buttler, Alexandre, Slowinska, Sandra, Slowinski, Michal, Lara, Enrique, Lamentowicz, Mariusz, Mitchell, Edward

Current projections suggest that climate warming will be accompanied by more frequent and severe drought events. Peatlands store ca. one third of the world’s soil organic carbon. Warming and drought may cause peatlands to become carbon sources through stimulation of microbial activity increasing ecosystem respiration, with positive feedback effect on global warming. Micro-eukaryotes play a key role in the carbon cycle through food web interactions and therefore, alterations in their community structure and diversity may affect ecosystem functioning and could reflect these changes. We assessed the diversity and community composition of Sphagnum-associated eukaryotic microorganisms inhabiting peatlands and their response to experimental drought and warming using high throughput sequencing of environmental DNA. Under drier conditions, micro-eukaryotic diversity decreased, the relative abundance of autotrophs increased and that of osmotrophs (including Fungi and Peronosporomycetes) decreased. Furthermore, we identified climate change indicators that could be used as early indicators of change in peatland microbial communities and ecosystem functioning. The changes we observed indicate a shift towards a more “terrestrial” community in response to drought, in line with observed changes in the functioning of the ecosystem.

, Geisen, Stefan, Mitchell, Edward, Wilkinson, David M, Adl, Sina, Bonkowski, Michael, Brown, Matthew W, Fiore-Donno, Anna Maria, Heger, Thierry, Jassey, Vincent E.J, Krashevska, Valentyna, Lahr, Daniel J.G, Marcisz, Katarzyna, Mulot, Matthieu, Payne, Richard, Singer, David, Anderson, Roger O, Charman, Dan J, Ekelund, Flemming, Griffiths, Bryan S, Rønn, Regin, Smirnov, Alexey, Bass, David, Belbahri, Lassaâd, Berney, Cédric, Blandenier, Quentin, Blandenier, Quentin, Chatzinotas, Antonis, Clarholm, Marianne, Dunthorn, Micah, Feest, Alan, Fernández, Leonardo D, Foissner, Wilhelm, Fournier, Bertrand, Gentekaki, Eleni, Hájek, Michal, Helder, Johannes, Jousset, Alexandre, Koller, Robert, Kumar, Santosh, La Terza, Antonietta, Lamentowicz, Mariusz, Mazei, Yuri, Santos, Susana S, Seppey, Christophe V.W, Spiegel, Frederick W, Walochnik, Julia, Winding, Anne, Lara, Enrique

Protists are the most diverse eukaryotes. These microbes are keystone organisms of soil ecosystems and regulate essential processes of soil fertility such as nutrient cycling and plant growth. Despite this, protists have received little scientific attention, especially compared to bacteria, fungi and nematodes in soil studies. Recent methodological advances, particularly in molecular biology techniques, have made the study of soil protists more accessible, and have created a resurgence of interest in soil protistology. This ongoing revolution now enables comprehensive investigations of the structure and functioning of soil protist communities, paving the way to a new era in soil biology. Instead of providing an exhaustive review, we provide a synthesis of research gaps that should be prioritized in future studies of soil protistology to guide this rapidly developing research area. Based on a synthesis of expert opinion we propose 30 key questions covering a broad range of topics including evolution, phylogenetics, functional ecology, macroecology, paleoecology, and methodologies. These questions highlight a diversity of topics that will establish soil protistology as a hub discipline connecting different fundamental and applied fields such as ecology, biogeography, evolution, plant-microbe interactions, agronomy, and conservation biology. We are convinced that soil protistology has the potential to be one of the most exciting frontiers in biology.