Fundamental mechanisms enabling plant species to survive in all but the harshest terrestrial environments are owed in part to their interaction with the microbial world. A suite of novel genomics and metabolomics tools and rapidly increasing computational power promise a new wave of advances also in plant symbiosis research based on the study of a much wider range of plant and microbial species and on exploring diversity within species.

Interested candidates can join one of four thematically linked subprojects in which we currently explore the mechanistic basis and regulatory logic underlying plant symbioses with fungal microbes and how they affect plant and fungal growth and fitness.

The model plant Lotus japonicus lives in symbiosis with soil-borne arbuscular mycorrhizal fungi. In project A the focus is on the symbiotic interface and the molecular regulation of bi-directional exchange of nutrients and metabolic compounds at this interface. We are wondering how mycorrhizal plant and fungus regulate the formation of their symbiotic structures within the root or repress intraradical fungal growth by early senescence and degradation of these structures called arbuscules. This work will be performed in collaboration with the Cologne Center for Genomics.

Project B. Brassicaceae species like Arabidopsis thaliana do not form a mycorrhizal symbiosis but harbor numerous often unknown fungal endophytes which live as commensals or symbiotically supporting plant life. Interactions between endophytes and different Brassicaceae species at the species and community level will be explored including the study of whether the plant genotype affects fungal endophyte community and if, why? The project is located at the interface between ecological genetics and molecular physiology and is supported by collaborations with colleagues from the Max Planck Institute of Plant Breeding Research in Cologne.

In project C the function of a sphingolipid signal which has not been identified in plants before is being explored. The same lipid has been shown to be involved in human diseases. This signal compound is thought to influence plant growth and plant-microbe interactions through activation of calcium channels. Tissue-specific and subcellular functions and downstream effects will be studied using the model plant Arabidopsis thaliana, RNA-sequencing technology, and fluorescent calcium sensors in collaboration with colleagues from the University of Würzburg, Heidelberg and the IPB in Halle.

In project D natural variation in the PHO regulon which controls the response of plants to phosphate starvation stress, and how the PHO regulon influences endophyte communities and the development of plant-fungus symbioses is in the center of our interest.