Partenaires et organisations internationales
(Anglais)
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A, B, CZ, DK, FIN, F, D, H, IRL, I, NL, N, PL, P, RO, E, S, CH, GB
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Résumé des résultats (Abstract)
(Anglais)
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The industrial output of sulfur (S) containing compounds has been greatly reduced in recent years. As a result the deposition of atmospheric S-compounds into soils drastically decreased leading to S-deficiency in some European soils that negatively affects agricultural production in terms of both crop yield and crop quality. Field observations indicate a possible correlation between soil S-deficiency with enhanced disease susceptibility of the important crop plant Brassica napus. The aim of our study was to investigate the effect of S-deficiency on pathogen resistance of B. napus under controlled conditions. To this end we have analysed the S-deficiency-induced changes in disease susceptibility of two B. napus cultivars against three fungal pathogens. Our results clearly show that S-starved plants are more susceptible to the three tested fungal pathogens Leptosphaeria maculans, Botrytis cinerea and Phytophthora brassicae. The reduction in disease resistance correlated with a loss of antifungal potential of extracts of S-starved plants indicating that S-deficiency interferes with the production of S-containing antifungal compounds. Lipophilic extracts of S-starved plants contained greatly reduced levels of S-containing glucosinolates compared to control plants and were unable to inhibit the growth of two fungal pathogens in in vitro assays while similar extracts from contol plants strongly inhibited fungal growth. Together our results demonstrate that S-deficiency in B. napus interferes with general disease resistance and that this reduction in resistance is not only caused by a global loss of fitness but by the reduced accumulation of specific S-containing antifungal compounds such as the glucosinolates.
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