Ph.D.
Division Director
Division of Plant Science and Technology
Professor of Beneficial Plant-Microbe Interactions
Division of Plant Science and Technology
Research at a glance
Area(s) of Expertise
Research Summary
In many environments, plant performance is limited by a variety of abiotic and biotic stresses, such as nutrient deficiency, drought, or root and shoot pathogens. All land plants are associated with complex microbiomes, and many microorganisms that colonize plants are beneficial and improve the resistance of plants against a variety of stresses. The main research focus in the lab is to contribute to a better understanding of beneficial plant microbe interactions with the goal to develop microbial biofertilizers or bioprotectors.
Plants are metaorganisms that engage in intimate associations with a wide diversity of microorganisms. Many of these microorganisms are beneficial and help plants to overcome a variety of abiotic and biotic stresses. In our research, we focus particularly on arbuscular mycorrhizal (AM) fungi and nitrogen fixing rhizobia bacteria. AM fungi played a significant role during land plant evolution and form close interactions with the roots of 70% of land plants, including many agronomically important species, such as corn, soybean, or wheat. AM fungi increase the nutrient acquisition of for example phosphate, nitrogen, sulfur, and potassium from the soil, and improve the resistance of plants against abiotic stresses, such as drought, salinity, heavy metals, and biotic stresses (root and shoot pathogens). Rhizobia convert gaseous nitrogen into plant available forms of nitrogen via biological nitrogen fixation and reside in the root nodules of legumes. Plants are simultaneously colonized by communities of AM fungi and rhizobia, and the microbial partners differ in their benefit that they provide for the host plant. In exchange for these benefits, plants invest a significant percentage of their photosynthetic products into these root symbioses. In order for the symbiosis to be beneficial for the host plant, the benefits of these interactions must outweigh the carbon costs of these root symbioses. How host plants regulate the carbon flux to each root symbiont and how this carbon transport affects the competition among different root symbionts for plant derived carbon, or the microbial community composition is largely unknown. We use stable isotope labeling to track nutrient transport in different root symbioses, examine how different root symbionts affect the abiotic and biotic stress resistance of the plant, observe shifts in the microbial community composition of plants under different conditions, and use different next generation sequencing and localization technologies to identify the important drivers of resource exchange processes in different root interactions.
Educational background
- Ph.D. University of Bremen, Germany