CRT1 is a nuclear-translocated MORC endonuclease that participates in multiple levels of plant immunity.

Arabidopsis thaliana CRT1 (compromised for recognition of Turnip Crinkle Virus) was previously shown to be required for effector-triggered immunity. Sequence analyses previously revealed that CRT1 contains the ATPase and S5 domains characteristic of Microchidia (MORC) proteins; these proteins are associated with DNA modification and repair. Here we show that CRT1 and its closest homologue, CRH1, are also required for pathogen-associated molecular pattern (PAMP)-triggered immunity, basal resistance, non-host resistance and systemic acquired resistance.