Comparative and functional analysis of secreted proteins of the oomycete Hyaloperonospora arabidopsidis

The research described in this thesis focused on Hyaloperonospora arabidopsidis, the downy mildew of thale cress. This oomycete pathogen is an obligate biotroph, meaning it requires living host cells throughout its entire life cycle. Related downy mildews cause severe damage to crops such as grapes, sunflower and spinach. Also, related oomycetes of the genus Phytophthora, which are highly destructive plant pathogens, start their lifecycle in a similar fashion as downy mildews, yet quickly after infection kill the invaded host tissues. Gaining a better understanding of downy mildew infection of thale cress can therefore provide crucial knowledge of infection mechanisms leading to plant disease, and generate vital clues for the protection of crop plants against oomycete pathogens. The main focus of this thesis are two groups of secreted proteins, which are secreted by the pathogen during infection: Nep1-Like Proteins (NLPs) and Hexose 6-Phosphate Epimerase-Like proteins (H6PELs).