GENES AND PATHWAYS THAT BOOST WHEAT RESISTANCE TO STRIPE RUST

The overarching goal of this project is to identify genes and pathways in wheat that are responsible for enhanced broad-spectrum resistance against stripe rust and to fine-tune their activation. We plan to conduct detailed phenotypic characterization of a panel of newly isolated wheat mutants with heritable dominant enhanced disease resistance to wheat stripe rust, to identify the causative mutations, and then test engineered cassettes that will bypass any pleiotropic effects of the enhanced resistance.Goal 1: Phenotype gain-of-resistance wheat mutants, analyze effects of resistance on yield and its interaction with the environment.The overall goal is to determine how enhanced disease resistance phenotypes in our mutant lines stop the pathogen, to gain insight into molecular pathways, their intensity of expression and how they are regulated by temperature. We will also conduct more field analyses, with precise measurements of any tradeoffs with yield and susceptibility to necrotrophic pathogens.Objective 1.1 Identify at which point during the infection cycle pathogen is stopped.Objective 1.2 Characterize induction of immune responseObjective 1.3 Evaluate induction of immunity in wheat EDR lines under different temperaturesObjective 1.4 Evaluate tradeoff effects with yield and susceptibility to other pathogensGoal 2: Identify mutations responsible for increased resistance to stripe rust.Here, we will combine the newest sequencing technologies and bioinformatics analyses already established in our lab with classical genetics to rapidly map sources of resistance in our wheat mutant lines and to identify causative mutations. We will also integrate information from other plant systems, including prioritized mutations in the candidate EDR genes.Objective 2.1 Construct complementation groups and mapping populationsObjective 2.2 Identify markers linked to resistance using wheat exome capture and mapping-by-sequencingObjective 2.3 Fine map and isolate causative mutations using long-read technologiesObjective 2.4 Validate candidate genes and engineer discovered alleles in other genetic backgroundsGoal 3: Modulate activation of immunity in wheat using natural and synthetic promoters.Our overall goal is to engineer pathogen-inducible broad-spectrum resistance against biotrophic pathogens of wheat, such as stripe rust, with minimal detrimental effects on development or susceptibility to other pathogens.Objective 3.1 Mine existing datasets for pathogen-induced promotersObjective 3.2 Engineer activation of enhanced resistance alleles