Screening Arabidopsis thaliana populations for disease resistance against Xanthomonas campestris pv campestris.
M. VAN HULTEN (1), S. Chatterjee (1), H. van den Burg (1) (1) Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, Netherlands

Back Rot, caused by the bacterium Xanthomonas campestris pv. campestris (Xcc), is considered one of the most important diseases of Brassica crops worldwide. Xcc is one of the few pathogens that primarily enter the plant through specialized organs on the leaf margins, called hydathodes, which are in direct contact with the vasculature of the plant. From the hydathode, Xcc further colonizes the xylem vessels. In the past, studies on resistance against Xcc have predominantly focused on mechanisms that take place once the bacteria are inside the plant. Hereto, bacteria are usually directly applied into the vascular system by wounding in the mid-vein. We have developed a robust Xcc infection in the model plant Arabidopsis thaliana, a member of the Brassicaceae family. This allows us to study Xcc pathogenicity and resistance without wounding or syringe-infiltration, but instead with spray-inoculation that mimics natural infection. Natural infection is mimicked as closely as possible, by promoting the formation of guttation droplets at the hydathodes, followed by stimulating bacterial up-take via re-uptake of the guttation into the plant. This set-up allows us to study mechanisms that prevent Xcc invasion that may already operate at early infection stages, prior to biofilm formation in the xylem. Using this bioassay we are currently screening various large Arabidopsis populations in search of new resistance mechanisms against Xcc.

Abstract Number: P17-631
Session Type: Poster