Grant: Discovery Grants Program - Individual

Plants have evolved sophisticated defense mechanisms as a survival strategy to fend off microbial pathogens. Recognition of pathogens by plant immune receptors leads to activation of downstream signaling cascades resulting in resistance to pathogens not only in the infected tissue, but throughout the entire plant. From past research, we have obtained a series of extraordinary mutants with auto-activated resistance responses mediated by three different types of immune receptors. To identify signaling components required for immunity downstream of these receptors, we have designed and carried out genetic screens to search for suppressors of these mutants. We are planning to isolate the suppressor genes using modern molecular genetic approaches, and study in detail the functions of proteins encoded by them. The proposed research efforts will help us better understand how immunity mediated by these immune receptors is regulated. Local resistance responses also activate a secondary defense mechanism in the remote parts of plants termed systemic acquired resistance (SAR). SAR is long lasting and effective against a broad spectrum of pathogens. Using a high-throughput SAR assay we recently developed, we have conducted genetic screens and identified a large number of mutants defective in SAR. We are planning to identify the mutant genes and study the functions of proteins encoded by them, which will help us better understand how SAR is established and regulated. Our research is crucial for advancing our knowledge of how plant immunity is regulated. New regulators and signaling pathways involved in plant defense responses will be discovered. The knowledge obtained will contribute to the development of new strategies to better manage plant disease problems not only in Canada, but around the world.