Investigation of host response in the pathosystem Solanum tuberosum L. / Rhizoctonia solani Kühn AG-3
F. GENZEL (1), P. Franken (2), R. Grosch (1) (1) Leibniz Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V., Germany; (2) Humboldt University of Berlin, Germany

An understanding of plant defense mechanisms is a crucial aspect in the development of strategies to control plant pathogens. Using potato cultivars with a high degree of resistance against black scurf is an environmentally friendly strategy. Potato cultivars show different levels of susceptibility to the soil-borne pathogen R. solani AG-3 PT (Potato). At present, the molecular background of these differences is unknown. There are a few studies on interactions between potato and R. solani. Differences in susceptibility are not based on gene-for-gene interactions but quantitative resistance. To get insight into plant responses to the fungus we studied the expression of common defense-related genes in roots and sprouts of a susceptible cultivar via RT-qPCR analysis at a time scale after an inoculation with R. solani AG-3 PT. Thus, we determined that the pathogen affects the expression of several defense-related genes in the studied tissue. An up-regulation of genes coding for chitinase, PR-1 and PR-2 was observed in inoculated roots and sprouts 3 and 6 days post inoculation (dpi) compared to non-inoculated treatment. In a following experiment, including a less susceptible cultivar, the expression of PAL and PR-2 was significantly higher in non-inoculated and inoculated sprouts of the less susceptible compared to the more susceptible cultivar. This leads to the hypothesis that an increased expression of PAL and PR-2 is associated with lower susceptibility to R. solani AG-3.

Abstract Number: P18-672
Session Type: Poster