Sufficient and sustainable production of food, feed and renewable resources is one of the greatest challenges for the 21st century. Microbial pathogens threaten the amount and quality of crop yield in agriculture and horticulture. Climate change and rapid evolution of pesticide resistance and virulence by the pathogens further complicate strategies for durable crop protection. By contrast, plant immunity is the basis of sustainable production of healthy plants. We aim at a detailed understanding of plant immunity and of how successful microbial pathogens overcome immunity to cause disease. Additionally, we aim at understanding of evolution and epidemics of plant diseases in the field for optimization of risk assessment and integrated plant protection.