Functional stability of a customised nitrogen-fixing microbiome under changing environments

• Applicant: Professor Dr. Patrick Schäfer
• Subject Area: Plant Breeding and Plant Pathology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 545739974

Agricultural plant production is a resource-intensive process that is increasingly challenged by changing climates. Solutions for a more sustainable and resilient way of plant production are therefore urgently required. Plant roots are a habitat for highly complex microbial communities and plants benefit from intimate interactions with these microbes. In addition to mediating tolerance against climate stress, some microbes can improve plant nutrition. While it indicates the value of microbes to sustain plant production, field applications with individual beneficial microbes often do not meet their beneficial activities observed under lab conditions. In previous joint studies, we identified the nodulating bacteria Sinorhizobium meliloti WSM1022 as highly efficient in supplying the legume Medicago truncatula with nitrogen (N) in different soil types. Moreover, we found that WSM1022 can modulate the root microbiome to form a mini-microbiome that, together with WSM1022, we defined as the N-biome. In addition to supporting N-fixation the N-biome appears to transfer additional benefits to M. truncatula. In this project we aim to evaluate the robustness of the N-biome-M. truncatula symbiosis under different N regimes and drought as prevalent climate stress using greenhouse settings with field soil. We will quantify the efficiency of nodulation and N-fixation, plant growth and development as well as the expression of symbiosis and drought stress marker genes to evaluate functional robustness of the N-biome-M. truncatula symbiosis. We will further apply genome-wide association studies to identify genetic traits of M. truncatula that support N-biome establishment under drought stress. All experiments are paralleled by root microbiome analyses to determine N-biome integrity or even its functional expansion by recruiting additional beneficial microbes under these changing environments. Our project thus aims to develop the N-biome as a biological entity for future field applications.

• DFG Programme: Research Grants
• International Connection: United Kingdom
• Partner Organisation: Biotechnology und Biological Sciences Research Council (BBSRC)
• Cooperation Partners: Professor Dr. Gary Bending; Professorin Dr. Miriam Gifford