Interaction structures with host cells and molecular phylogenetic studies of the Dothideomycetes with particular emphasis on (hemi-)biotrophic plant parasites

丝状真菌是一大类真菌，包括大量的植物病原菌和一些人和动物的病原体，对于了解子囊菌的系统发育和它们的生活方式是至关重要的。尽管它们在经济和科学上具有重要意义，但在几乎所有的分类水平上，从目的界定到物种的界定，这一组内的许多分类学问题仍然没有得到解决。在我们以前的工作中，我们已经描述了三叶草(Cymadothea Trifolii)形成的一种复杂类型的细胞相互作用，三叶草是一种生活在三叶草属植物叶片中的专性生物营养病原菌。我们申请的这个项目的初始假设是，多菌群中的生物营养作用可能是一种祖先特征。此外，不同的细胞相互作用模式可能反映不同的分类关系，就像担子菌黑粉菌所显示的那样。因此，我们想要彻底分析大量(半)生物营养的假单胞菌与宿主细胞(例如细胞内的菌丝、吸器)实现的特定相互作用。所涉及的问题是，某些类型的相互作用是否仅限于特定的分支(由遗传数据证实)，以及是否可以追溯从简单结构到复杂结构的发展(例如，带有相互作用装置的胞内菌丝和胞间菌丝)。这项研究结合了电子显微镜和使用四个遗传标记(nuSSU rDNA、nuLSU rDNA、RPB 1+2)的多基因方法的分子分析。其目的是验证上述假设，并了解真菌与光合作用生物相互作用的进化。

The Dothideomycetes is a major group of fungi that includes numerous phytopathogenous species and some human and animal pathogens and is crucial for an understanding of the phylogeny of ascomycetous fungi and their life-styles. Despite their economic and scientific importance many taxonomic questions within this group remain unsolved at almost all taxonomic levels from circumscription of orders to species delimitation. In our previous work we have described a complex type of cellular interaction formed by Cymadothea trifolii (sooty blotch of clover), an obligate biotrophic pathogen living in leaves of Trifolium species. Our starting hypothesis for the project applied for is that biotrophism within the Dothideomycetes may be an ancestral character. Furthermore, different modes of cellular interaction might reflect distinct taxonomic relationships, as has been shown for the basidiomycetous smut fungi. Consequently, we want to thoroughly analyse a large number of (hemi-)biotrophic Dothideomycetes for the specific interactions realized with host cells (e.g. intracellular hyphae, haustoria). The questions addressed are, whether certain types of interaction are restricted to specific clades (validated by genetic data), and whether a development from simple to complex structures can be traced back (e.g. intracellular hyphae ¿¿haustoria ¿¿intercellular hyphae with interaction apparatus). This study incorporates electron microscopy and molecular analyses employing a multi-gene approach with four genetic markers (nuSSU rDNA, nuLSU rDNA, RPB 1 + 2). The aim is to test the above hypotheses and to understand the evolution of interactions of fungi with photosynthetic organisms.