My research focuses on the protist microbiota of maize and their functional roles for the self-organization of the rhizosphere bacterial microbiome.

Plants recruit specific subsets of the soil bacterial community by the provision and species-specific composition of root exudates. The genetic repertoire of these rhizosphere bacteria, the ‘microbiome’, is thought to enrich the plant genome with specific traits, such as the production of hormones or their ability to mineralize specific nutrients.

Currently, bacterial microbiomes are viewed as rather static communities despite roots are highly dynamic systems.

Mucilage at root tips and exudates at the sites of root hair formation are provided as substrate pulses in time and space causing rapid growth of bacterial communities. Subsequent predation of these bacterial communities by protists will exert drastic changes on bacterial community dynamics, but at the same time exerts a feedback on the community composition of predators. We believe that the dynamic coupling of bottom-up (by exudate resources) and top-down control (by protist predators) is a key mechanism stabilizing the self-organization of rhizosphere microbiomes.

In microcosm and field experiments, I investigate prokaryote and protist community composition by applying high throughput sequencing and further methods addressing the community function.

My project (P14) is implemented in the priority program ‘Rhizosphere Spatiotemporal Organisation – a Key to Rhizosphere Functions’ (PP2089) funded by the German Research Foundation (DFG, Deutsche Forschungsgemeinschaft). Hypothesizing that resilience emerges from self-organised spatiotemporal pattern formation in the rhizosphere, this program aims at the identification of spatiotemporal patterns in the rhizosphere and at the explanation of the underlying mechanisms.