MKP1 regulates plant metabolite signals that induce bacterial virulence: How and where are these signals controlled?

Many plants normally become infected by bacterial pathogens that then cause reduced food yields or even death. However, the investigators recently discovered a mutant plant with a novel mechanism for enhanced resistance against bacterial pathogens whereby the plant prevents the bacteria from becoming infectious. In this project, the investigators will determine how the mutant uniquely stops the pathogen by studying both the location of and the mechanism(s) controlling this resistance. The investigators will also examine if the mutant has enhanced resistance against other types of pathogens (e.g. fungal pathogens) or if the mutation causes a trade-off of enhanced resistance against one type of pathogen at the expense of increased susceptibility to another. The goal of this project is to determine if there is a novel, genetic means of improving crop survival against pathogens without any unintended penalties.<br/><br/>Most pathogenic bacteria express a type three secretion system (T3SS) to suppress the plant's immune responses, thus allowing the pathogen to acquire nutrients needed to replicate. The investigators recently identified an Arabidopsis mutant (mkp1) that produces less of the chemical signals that induce the T3SS in bacteria, thus resulting in a plant with enhanced resistance. Translating this discovery into improved resistance in the field requires a better understanding of the underlying principles. Does MKP1 regulate levels of transporters controlling movement of metabolites across the plasma membrane (PM) to restrict the chemical signals (addressed by quantitative plasma membrane proteomics)? Does MKP1 regulate the cellular production of these metabolites (addressed by quantitative metabolomics)? Do all cell types in the leaf contribute equally to the production of the metabolites and, therefore, resistance (addressed by cell/tissue-specific complementation? Finally, it is critical to test an informative spectrum of pathogens to determine if resistance in mkp1 extends to other types of pathogens or, perhaps more importantly, if the changes in mkp1 may have negative consequences making it more susceptible to unrelated pathogens. A better understanding of this apparently novel mechanism of resistance may provide an important basis for improving sustainable resistance in the field. The investigators will expand a Plant Biology & Public Policy Workshop they developed for undergraduates where students learn how policy makers at the local, state, and national level affect research at universities. Students will learn to communicate the importance of basic research by providing the most useful information.