The NLR protein ZAR1 interacts with ZRKs and PBLs to form a pentameric resistosome, triggering immune responses. Here, we show that ZAR1 emerged through gene duplication and ZRKs derived from cell surface immune receptors WAKs through losing extracellular domain before the split of eudicots and monocots in the Jurassic. Many angiosperm ZAR1 orthologs, but not ZAR1 paralogs, are capable of oligomerization in the presence of AtZRKs and triggering cell death, indicating the functional ZAR1 resistosome might have originated during the early evolution of angiosperms. Surprisingly, inter-specific pairing of ZAR1 and AtZRKs often results in the formation of resistosome in the absence of pathogen stimulation, suggesting a with-in-species compatibility between ZAR1 and ZRKs as a result of co-evolution. Numerous concerted losses of ZAR1 and ZRKs occurred in angiosperms, further supporting the ancient co-evolution between ZAR1 and ZRKs. Our findings provide insights into the origin of new plant immune surveillance networks.
The origin and evolution of a plant resistosome