HOST-PATHOGEN INTERACTIONS IN BARLEY AND WHEAT
Location: Cereal Crops Research
Project Number: 5442-22000-048-00
Start Date: Mar 21, 2012
End Date: Mar 20, 2017
This research involves characterization of host-pathogen interactions and pathogen biology in both fungal and viral pathogen systems in order to facilitate a better understanding of the fundamental processes resulting in resistance, or susceptibility and disease development. Specific objectives: 1. Characterize necrotrophic effectors from Stagonospora nodorum, the causal agent of Stagonospora blotch of wheat, and determine their association with the corresponding wheat susceptibility genes. Apply this information to develop procedures useful in the selection and identification of resistant wheats. 2. Identify and characterize virulence factors of Pyrenophora teres f. teres, and P. teres f. maculata, causal agents of net form net blotch and spot form net blotch of barley, respectively, to elucidate and exploit the mechanism for resistance to these diseases. 3. Identify viral genome sequences and interactions affecting pathogenicity, virulence, and transmissibility of viruses infecting barley, particularly barley stripe mosaic virus and oat blue dwarf virus.
Fungal and viral diseases of small grains pose an economic threat to production throughout the U.S. and the world. This project focuses on both fungal and viral pathogens in an effort to solve issues related to pathogenicity, virulence, and host resistance. It is our goal to identify and characterize pathogenicity/virulence factors of Pyrenophora teres (net blotch of barley), Stagonospora nodorum (S. nodorum blotch of wheat), barley stripe mosaic virus (BSMV), and oat blue dwarf virus (OBDV), and evaluate their importance in disease production. Our approach will be to: a) Identify and characterize virulence determinants and host genes important in net form net blotch and spot form net blotch of barley through phenotyping and mapping of segregating host and pathogen populations. Host resistance genes will be mapped and characterized, and pathogen virulence genes will be mapped, characterized, and cloned. Additionally, the newly acquired P. teres f. teres genome sequence will be used to identify necrotrophic effectors (NEs) involved in disease induction. b) Identify and characterize NEs and their corresponding host sensitivity genes important in S. nodorum blotch of wheat. Host-pathogen interactions will be characterized through evaluation of host mapping populations and identification of new NEs through purification and bioinformatic analysis. c) Identify and characterize factors affecting pathogenicity, virulence, and transmissibility of viruses infecting barley through the characterization of BSMV and OBDV model systems. A reverse genetics approach will be used to analyze viral phenotypes and further elucidate genome structure-function relationships. The knowledge gained may ultimately lead to the discovery or development of novel and effective control measures for viral diseases of barley and fungal diseases of both barley and wheat.