The potential of sulfur induced resistance against plant diseases of oilseed rape
The contribution of essential plant nutrients to resistance against diseases saw some interest in the past, but research in this field has been limited by its complexity and its practical significance unrecognized due to the availability of effective pesticides.The term Sulfur Induced Resistance (SIR) denotes the reinforcement of the natural resistance of plants against fungal pathogens through triggering the stimulation of metabolic processes involving sulfur by targeted sulfate-based and soil-applied fertilizer strategies. The disease index, calculated from infection rate and infection severity, was reduced by sulfur fertilization up to 50％ in greenhouse and 35％ in field experiments. The sulfur metabolism in plants offers several options to combat fungal attacks. Plants emit sulfur-containing volatiles such as H2S which is commonly rated as being fungitoxic. So far, however, dose/effect measurements were non-existent and first measurements revealed that basidiomycetes such as Rhizoctonia ssp. metabolize H2S up to concentrations of 20 μl l-1 H2S within 16 h, while growth of Sclerotinia sclerotiorum was inhibited by the same concentration after 24 h. Other mechanisms involved in defense from biotic stress that are provided by the S metabolism of plants involve glutathione and here the glutathione/ascorbate cycle, cysteine, phytoalexins and glucosinolates. The results from comparative field experiments in northern Germany and Scotland revealed that sulfur fertilization significantly increased the total sulfur, cysteine and glutathione content on a sulfur deficient site. Infections with light leaf spot (Pyrenopeziza brassicae), stem canker (Leptosphaeria maculans) and downy mildew (Peronosporaparasitica) were the most severe diseases in Scotland. A significant increase in the cysteine and glutathione content was found in visually infected (P. brassicae) leaf tissue in northern Germany,while the same oilseed rape cultivars showed a 2.5-fold and 1.6-fold decrease in these metabolites in Scotland. An increased concentration of these components reveals enhanced defense mechanisms, while a reduction may indicate that these were either consumed for defense, or being the result of a successful establishment of the pathogen. Research in SIR revealed that there are sulfur-based crop and pathogen specific resistance mechanisms. A model is presented, which reflects chronologically synthesis of sulfur metabolites and related biochemical pathways which are putatively triggered by SIR in oilseed rape.
Elemental sulfur H2S Sclerotinia sclerotiorum sulfur fertilization
Silvia Haneklaus Elke Bloem Luit J.De Kok Zhihui Yang Shiping Wang Ewald Schnug
Institute of Plant Nutrition and Soil Science, Federal Agricultural Research Centre (FAL), Bundesall Laboratory of Plant Physiology, University of Groningen, P.O.Box 14, 9750 AA Haren, The Netherlands Department of Plant and Environmental Sciences, Norwegian University of Life Science, N-1432 Aas, No Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China
国际会议
第十二届国际油菜大会( The 12th International Rapeseed Congress)
武汉
英文
1307-1310
2007-03-26（万方平台首次上网日期，不代表论文的发表时间）