Cold priming on pathogen susceptibility in the Arabidopsis mutant background requires a functional .

24 h cold exposure (4°C) is sufficient to reduce pathogen susceptibility in against the virulent pv. () strain even when the infection occurs five days later. This priming effect is independent of the immune regulator Enhanced Disease Susceptibility 1 (EDS1) and can be observed in the immune-compromised null mutant. In contrast, cold priming-reduced susceptibility is strongly impaired in knock-out lines of the stromal and thylakoid ascorbate peroxidases (sAPX/tAPX) highlighting their relevance for abiotic stress-related increased immune resilience. Here, we extended our analysis by generating an double mutant. showed -like resistance and susceptibility phenotypes against strains containing the effectors avrRPM1 and avrRPS4. In comparison to , susceptibility against the wildtype strain was constitutively enhanced in . Although a prior cold priming exposure resulted in reduced titers in , it did not alter resistance in . This demonstrates that the genetic requirement for cold priming of basal plant immunity applies also to an null mutant background.