University of New Hampshire
Biochemistry, Molecular and Cellular Biology
Mentor: Dr. Kevin Culligan, Department of Molecular, Cellular, and Biomedical Sciences
Understanding the Role of Replication Protein A 1E in the Immune Response of Arabidopsis thaliana Against a Microbial Pathogen
Understanding the mechanisms of plant biotic defense is imperative to help decrease microbial pathogenicity against agricultural crops. Pathogens can potentially enhance infections by inducing DNA damage within the host. One example is DNA double-strand breaks caused by Pseudomonas syringae, a common bacterial pathogen in plants. Plants encode various mechanisms to repair double-strand breaks, including a pathway called homologous recombination repair that is regulated by the protein complex RPA (Replication Protein A). To test the role of a specific member of RPA in the model plant Arabidopsis thaliana, I propose here to genetically “knock out,” or eliminate the function of, the RPA1E gene in the host plant genome and test whether this affects susceptibility to pathogen infection. This will allow me to determine the importance of this protein in microbial plant defenses. Thus, the methodological goal is to determine whether knocking out this protein will increase or decrease hyper- susceptibility in A. thaliana by forcing a bacterial strain of Pseudomonas sryingae into the leaf stoma of A. thaliana through vacuum filtration. This assay will then be quantified by plating the bacterium from the leaf samples after 1 hour and 36 hours of infiltration and performing colony counts, and will be statistically analyzed through ANOVA. These results will ultimately provide a puzzle piece’s worth of insight in how agricultural crops defend themselves from microbial invasion by determining whether RPA1E responds to a pathogen infection and if it’s required in the defense response of A. thaliana.