To be able to survive environmental stresses, including attack by pathogens, plants have evolved complex mechanisms to survive. Organelles within the cell such as chloroplasts and mitochondria are thought to be in a prime position to sense and communicate stress signals and trigger adaptive and/or defence responses. However, the mechanisms on how intracellular organelles convey stress signals remain poorly understood, especially in plants. My research is based on the hypothesis that organelles can associate directly through contact sites to enable fast and efficient communication of stress signals. To tackle this question, I aim to identify stress-induced inter-organelle contact sites by means of high-end live-cell imaging and proteomics approaches. The second research question I aim to tackle is how pathogens manipulate the plant immune system by proteomics-based identification of pathogen-secreted effector proteins targeting plant organelles.