DISEASE SYMPTOMS AND MINERAL NUTRITION IN ARABIDOPSIS THALIANA IN RESPONSE TO VERTICILLIUM LONGISPORUM VL43 INFECTION
S. Floerl, C. Druebert, H.I. Aroud, P. Karlovsky, A. Polle
Verticillium longisporum is one of the most important pathogens of Brassicaceae. The goal of the present study was to characterize the development of V. longisporum (strain VL43) stress symptoms caused to Arabidopsis thaliana in relation to plant nutrition. Significant growth inhibition became apparent between 2 and 3 weeks after VL43 inoculation but was not accompanied by reduced leaf water content or wilting. The leaves of VL43-infected plants showed reduced chlorophyll content (-20%) but only marginal effects on photosynthetic electron transport of PS II (-2%) compared with controls. VL43-infection did not have negative effects on nutrient element concentration in leaf tissues during a five-week observation period. Measurements of fungal nutrient content in simulated xylem medium suggested that nutrient intake by VL43 was negligible compared to that of plant tissues. Therefore, growth retardation induced by VL43 infection is not a consequence of nutrient depletion.