Improving crop production is important both for enhancing the national economy and for stabilizing food security. However, plant pathogens greatly reduce crop yields, negatively impacting these important goals. One approach to crop pathogen management is to develop highly disease-resistant crops, and an important aspect of engineering durable crop pathogen resistance is elucidating and manipulating resistance pathways in model organisms. Increasing evidence shows that for a plant to manifest a fully active defense response against pathogens, cells need to make sure that the correct proteins are in the correct location. In this project, a novel hub controlling the cellular movement of defense-related proteins has been identified in the model plant Arabidopsis thaliana. Understanding the full roles and regulation of this hub can lead to unique strategies for improving crop protection. In addition to its biological importance, this project will provide multi-disciplinary training to better prepare young scientists to be successful members of the national scientific work force. In addition, undergraduate students will be recruited into an established, multi-lab research training program to improve the scientific understanding and literacy of first year university students.<br/><br/>The trans-Golgi Network/Early Endosome (TGN/EE) is a protein sorting station of increasing importance in plant immunity against diverse microbial pathogens in model and crops species. The role of the TGN/EE in trafficking of immune cargo proteins to/from the plant cell surface is critical, so that the cargo proteins can reach their site of function to establish effective defenses prior to or in response to pathogen infection. However, little is known about the molecular machinery that govern trafficking of immune cargo at the TGN/EE. Here, the PI and Co-PI will utilize cross-disciplinary approaches including immune-signaling and bacterial infection assays, plasma membrane and apoplast proteomics, and live-cell imaging to understand how the individual and combined roles of clathrin-coat proteins control their trafficking function at the TGN/EE to maintain the correct location and abundance of defense-related cargo proteins at the cell surface. Data and tools generated from this proposal will allow formulating new testable hypotheses on how to manipulate trafficking of defense cargo components for increased immunity to bacteria and other pathogens. PM proteins are involved in all aspects of plant biology from plant defense to development, hormone and nutrient acquisition. Thus, gained knowledge will generate insights into regulatory roles of clathrin-mediated trafficking beyond plant immunity. Broader Impact activities will include active participation in the MU-Freshman In Plant Sciences (FRIPS) Program to recruit MU-Freshmen into plant labs at an early stage. Training will include learning to design and perform experiments, analyze data, draw conclusions and communicate their results.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.