Location: Cereal Crops Research
Project Number: 3060-22000-051-000-D
Project Type: In-House Appropriated
Start Date: Mar 15, 2022
End Date: Mar 14, 2027
Objective 1. Functionally characterize the pathogen components of the Parastagonospora nodorum-wheat interaction. Sub-objective 1.A: Functionally characterize the role of SnTox5 in necrosis induction and colonization of the wheat leaf. Sub-objective 1.B: Characterize the role of SnTox267 in virulence using laser confocal microscopy. Objective 2. Characterize the infection strategies of Pyrenophora teres, the net blotch pathogen of barley. Objective 3. Identify, validate, and functionally characterize the Pyrenophora teres genes/proteins important in virulence on barley.
Fungal diseases pose an economic threat to plant crops throughout the world resulting in billions of dollars in losses annually. A significant amount of work has been done to understand biotrophic host-pathogen interactions. However, less progress has been made to understand the relationship between plants and their necrotrophic pathogens. Here we focus on understanding how the necrotrophic pathogens Pyrenophora teres, causal agent of net blotch of barley, and Parastagonospora nodorum, causal agent of septoria nodorum blotch of wheat, manipulate the host defense to allow pathogen colonization that results in disease. In previous work, we functionally validated several genes/proteins in P. nodorum that contributed to the pathogen’s infection strategy. Here, we will functionally characterize these effectors using modern tools. CRISPR-Cas9-based gene editing will be used to characterize regions of the proteins involved in virulence function, laser confocal microscopy will be used to visualize the role and mode of action of these effector proteins in planta, and comparative transcriptome sequencing of in planta effector infiltrations and inoculations will be used to characterize the host response to these effectors. To characterize the P. teres f. teres-barley interaction, we will identify and validate candidate effector genes conferring virulence on susceptible barley. Candidate genes will be identified and validated using both P. teres biparental and globally collected natural populations that differ in virulence. QTL analysis and genome wide association study (GWAS) analysis will be used to locate candidate genomic regions harboring effector genes. Once effector genes have been validated using CRISPR-based gene disruption, strains with and without the effector genes will be used in inoculation experiments to characterize the mode of action of each effector, ultimately resulting in the understanding of the infection strategy of the pathogen. This work will provide critical knowledge to breeders and other researchers targeting the control of these important diseases.