Genetic and molecular basis of the systemic modulation of maize (Zea mays L.) root system architecture and the rhizosphere microbiome by seminal roots to better adapt to drought

• Applicant: Professor Dr. Frank Hochholdinger
• Subject Area: Plant Breeding and Plant Pathology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 439906817

Maize root system architecture underwent substantial alterations during domestication and improvement by a combination of farmer selection and environmental adaptations around the globe. The microbiome that colonizes the rhizosphere surrounding plant roots plays an important role in promoting crop stress tolerance. In the first funding period of this project we demonstrated that seminal root number has increased during maize domestication followed by a decrease in locally adapted varieties in regions of limited water availability. Environmental, genetic and genomic analyses revealed past signatures of domestication and adaptation of maize roots and highlighted the genetic potential to improve drought tolerance in future crops. In the second funding period, we have two overall objectives. First, to gain a deeper understanding of the genetic and molecular basis of the systemic modulation of root morphology and anatomy by seminal roots to better adapt to limited water availability. To this end, will decompose the complex plant response and effect trait association underlying genes involved in root system architecture in response to drought. Second, to understand the host genetic role in determining the microbial community composition of the root trait-driven beneficial microbiome of the rhizosphere to enhance drought resilience in maize. In this context, we will systematically explore how host genetic variation and gene regulation affects the assemblage of the rhizosphere microbiome and enhances maize productivity and drought resilience. Finally, we will functionally validate representative key genes and keystone microbes via reverse genetics and synthetic microbial communities. These results will pave the way for improved crop breeding and the application of microbial resources to secure future food production and efficient resource usage in agriculture.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Peng Yu