Cell-surface-localized pattern-recognition receptors (PRRs) recognizing microbe-derived or plant-endogenous molecules play central roles in various plant-microbe interactions. PRR-triggered immunity (PTI) wards off a wide range of pathogenic microbes, playing a pivotal role in angiosperms. However, the existence or significance of PTI in non-flowering plants including bryophytes remains largely unclear. My group has been establishing the liverwort Marchantia polymorpha as a plant model for studying evolutionary molecular plant–microbe interactions (EVO-MPMI). In this talk, I will introduce our findings on PTI-related pathways in Marchantia polymorpha.