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。双方对这些变化的具体贡献及其对相互作用的影响尚未得到解决。本文将重点研究植物激素平衡在几种重要作物灰霉病的致病机制中的作用，以及作为其寄主植物的番茄。我们将采取一种综合的方法，将整个植物水平的实验与细胞水平的分子和生化研究结合起来。外用植物激素对植物对灰孢杆菌感染的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）。本文将采用生物化学和分子化学相结合的方法分析灰孢杆菌产生的植物激素在植物中的输入和重要性。对激素生物合成基因进行克隆和鉴定，重点是脱落酸、赤霉素和乙烯。从灰霉病菌中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。为了对植物激素的一般作用有一个更广泛的认识，我们将把灰芽孢杆菌系统与相关的白霉菌菌核菌和生物营养型白粉病真菌进行比较。这些研究将包括激素生物合成受阻和/或对植物激素易感性改变的确定的植物突变体。

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.