Die Rolle von Phytohormonen bei der Interaktion zwischen phytopathogenen Pilzen und ihren Wirtspflanzen

微生物与高等植物的相互作用往往伴随着植物激素水平的变化。这两个伙伴对这些变化的具体贡献及其对互动的影响尚未确定。本文以几种重要农作物灰霉病的致病因子--灰霉病菌为研究对象，以番茄为寄主植物，研究植物激素平衡在致病关联中的作用。将采取一种综合的方法，将整个植物层面的实验与细胞层面的分子和生化研究结合起来。外施植物激素对植物对灰霉病菌侵染敏感性的影响将被更详细地研究(包括植物激素作用的抑制剂或生物合成和混合物)。采用生物化学和分子生物学相结合的方法，对植物灰霉病菌产生的激素的输入和重要性进行分析。激素生物合成基因将被克隆和鉴定，重点是脱落酸、赤霉素和乙烯。从B.Cinerea获得的生物合成基因为分析真菌途径在植物中的表达提供了可能。转基因非和高产菌株将允许对特定真菌植物激素在相互作用中的作用进行功能分析。灰霉菌系统将与相关的白霉菌核盘菌和生物营养白粉菌Sphaerotheca fusca syn.为了更广泛地了解植物激素的一般作用。这些研究将包括激素生物合成受阻和/或对植物激素敏感性改变的明确的植物突变体。

Interactions of microorganisms and higher plants often are accompanied by changes in phytohormone levels. The specific contributions of both partners to these changes and their impact for the interaction are not yet resolved. Here the role of phytohormone balance in pathogenic associations will be studied focusing on Botrytis cinerea, the casual agent of grey mould of several important crop plants, and tomato as its host plant. A comprehensive approach will be taken integrating experiments at the whole plant level with molecular and biochemical studies at the cellular level. The influence of external application of phytohormones on the susceptibility of plants to infection by B. cinerea will be investigated in more detail (including inhibitors of phytohormone action or biosyntheses and mixtures). The input and importance of phytohormones produced by B. cinerea in planta will be analysed by combined biochemical and molecular methods. Hormone-biosynthetic gene will be cloned and characterized, focusing on abscisic acid, gibberellins, and ethylene. The availability of biosynthesis genes from B. Cinerea opens the possibility to analyse the expression of the fungal pathways in planta. Transgenic non- and overproducing strains will allow fuctional analyses of the role of specific fungal phytohormones for the interaction. The B. cinerea system will be compared with the related white mould fungus Sclerotinia sclerotiorum and the biotrophic powdery mildew fungus Sphaerotheca fusca syn. fuliginea in order to gain a broader view of the general role of phytohormones. Defined plant mutants with blocked hormone biosynthesis and/or altered susceptibility to plant hormones will bei included in these studies.