"Stomata are pores in the leaf epidermis allowing CO2 uptake essential for photosynthesis, but make plants vulnerable to water loss and pathogen invasion. Plants have therefore mechanisms to close stomata in response to microbes, which, however, must be balanced with the regulation of stomatal movements for photosynthesis and abiotic-stress parameters. The pathways and integration of diverse signals leading to stomatal closure still remain elusive, and how stomatal apertures are regulated to control pathogen invasion is a major biological question. My long-term objective is to understand how stomatal aperture is controlled in biotic stresses, how this interacts with abiotic stresses, and how membrane trafficking, an unexplored mechanism of stomatal movements, contributes to stomatal closure. The rationale behind this research relates to a novel high throughput imaging method monitoring the dynamics of stomatal behaviors, and exciting preliminary data that suggest specific and overlapping functions of some of the underlying genes regulating stomatal closure as well as a role for membrane trafficking stomatal movement.The overall aim of this proposal is to identify the molecular components of stomatal immunity and the genetic networks of stomata control. In order to achieve this, the specific objectives contained in this proposal are to understand:1. What are the molecular components of pathogen-induced stomatal closure?2. How does pathogen-induced stomatal closure interact with abiotic stresses?3. How does membrane trafficking contribute to stomatal closure?I will investigate these questions using a combination of cell biology advanced imaging, genetic approaches and computational modelling that will allow me to dissect the significance and specificity of biotic and abiotic-stress induced stomatal closure and membrane trafficking in this context. This will pioneer new avenues from which to investigate and understand a plant’s interaction with its environment."