This project is part of COST Action FA1208 "Pathogen-informed strategies for sustainable broad-spectrum crop resistance". Late blight, caused by the oomycete Phytophthora infestans, is one of the major threats in potato (Solanum tuberosum) and tomato (Solanum lycopersicum) production. Facing the goals of COST Action FA1208 to gain knowledge on effector targets and host processes, this project aims to deliver results on specific targets of P. infestans, as well as local and systemic reactions of the host plant. Furthermore the results will enable to develop general sampling strategies for standard protocols as well as for projects on field and greenhouse grown tomatoes. Therefore using a NGS approach we will investigate plant reaction during early infection stages of generalist (Botrytis cinerea, grey mold) and more specialist pathogens (P. infestans and Oidium neolycopersici, powdery mildew). Based on transcriptome data of disease-challenged tomato leaves late blight specific genes will be selected and their spatio-temporal expression patterns studied in the whole plant. This project will deliver (1) a comparative study of plant reaction toward different pathogen species of diverse specificity, (2) spatiotemporal expression patterns of tomato plants reacting to an infection, and (3) a field applicable sampling strategy and qPCR assay for early detection of an infection with P. infestans. Side projects will reveal (a) molecular markers associated to tomato genes expressed during pathogen attack, and (b) a comparative study of the disease-related gene expression in annual and perennial crops.