Exploiting natural genetic diversity and mutant resources of Arabidopsis thaliana to study the A-thaliana-Plasmodiophora brassicae interaction

Clubroot, caused by the obligate biotroph Plasmodiophora brassicae Woron., is one of the most damaging diseases of Brassica crops in the world. Because the pathogen can infect all the Brassicaceae, including Arabidopsis thaliana, possible advantages have been found by identifying sources of resistance to P. brassicae in this model plant. Fifty-seven ecotypes of A. thaliana, including the INRA Arabidopsis core collection, were assessed for resistance to clubroot disease. Ecotypes Burren (Bur-0), Tsu (Tsu-0) and Kaunas (Kn - 0) were identified as partially resistant to P. brassicae isolates eH and/or Ms6. Fifteen Arabidopsis mutant lines known for certain physiological processes potentially involved in the host-pathogen interaction were evaluated for their resistance/susceptibility to P. brassicae. Mutant axr3-1 appeared to be less susceptible than the wild type Columbia, supporting the hypothesis of the involvement of the auxin pathway in the development of clubs.