ARS | Publication request: Dissection of effector-induced host susceptibility pathways in Stagonospora nodorum blotch of wheat

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: March 12, 2010
Publication Date: June 1, 2010
Citation: Lu, S., Friesen, T.L., Faris, J.D. 2010. Dissection of effector-induced host susceptibility pathways in Stagonospora nodorum blotch of wheat.Phytopathology 100:S151

Technical Abstract: The necrotrophic Stagonospora nodorum-wheat interaction is characterized by several pathogen-derived proteinaceous host-selective toxins (SnToxA, SnTox1, SnTox2, SnTox3 and SnTox4) that induce diseases in the host carrying a corresponding dominant susceptibility gene (Tsn1, Snn1, Snn2, Snn3 and Snn4, respectively). The major susceptibility gene Tsn1 has been found to encode a novel protein kinase-NBS-LRR disease resistance-like protein (Faris et al, unpublished) that does not directly interact with SnToxA. To dissect the pathways associated with these toxin-susceptibility gene interactions, we have undertaken yeast two-hybrid studies in conjunction with co-immunoprecipitation to identify wheat proteins that are directly targeted by the toxin or interact with the host susceptibility gene product. Several new ToxA-interacting proteins were identified including members of the pathogenesis-related protein (PR) families. Preliminary cDNA library screening also revealed that Tsn1 may interact with a protein potentially involved in the transfer of lipid receptors to the plasma membrane and two chloroplast proteins known to be involved in photosynthesis. These raise the possibility that Tsn1 may have a dual function and likely act as a key mediator for ToxA internalization. Results from further characterization of these candidate Tsn1-interacting proteins will be presented. Hypotheses on how Tsn1 governs ToxA-induced susceptibility in wheat will be discussed.