An evolutionary approach to understand the plant immune system
During the last several decades, extensive analyses revealed that plants utilize a two-branched immune system for defence against pathogens. In the first branch, transmembrane pattern recognition receptors (PRR), which are membrane-associated kinase or membrane-associated kinase interacting protein recognize and respond to slowly evolving pathogen-associated molecular patterns (PAMP). In the second branch, either a direct or an indirect recognition of the pathogen through disease-resistance (R) proteins is used for response to pathogen virulence factors (effectors). However, most insights gleaned to date have been mostly limited to seed plants. Consequently, we still know little about the conservation and diversification of the immune system among highly diverged plant species. Thus, we have been establishing tools to study immunity-related components in the model liverwort Marchantia polymorpha, a descendant of early diverging land plants. Importantly, M. polymorpha probably did not undergo whole-genome duplication, with the consequence that genetic redundancy is low. The majority of immune-related genes characterized in seed plants have been identified in M. polymorpha genome. The overall simplicity of gene families in M. polymorpha holds advantages for molecular genetic analysis. Analysis of M. polymorpha with simple gene/protein networks has great potential to understand ancestral and fundamental mechanisms in plant immune system. Our main goal is to illustrate a fundamental immune system in plants. In this project, we aim to characterize components that presumably play roles in immune system in M. polymorpha by taking genetic, transcriptomic and proteomic approaches.
The project will be supervised by Hirofumi Nakagami at the Max Planck Institute for Plant Breeding Research.