ARS | Publication request: Genetics of host-pathogen interactions in the wheat-Stagonospora nodorum pathosystem

Submitted to: International Wheat Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 30, 2008
Publication Date: September 24, 2008
Citation: Faris, J.D., Lu, H.J., Zhang, Z., Liu, Z.H., Xu, S.S., Chu, C.G., Abeysekara, N., Fellers, J.P., Cloutier, S., Keller, B., Scofield, S.R., Friesen, T.L. 2008. Genetics of host-pathogen interactions in the wheat-Stagonospora nodorum pathosystem. International Wheat Conference Proceedings. Australia Aug 24-29

Technical Abstract: Stagonospora nodorum causes the disease Stagonospora nodorum blotch (SNB) in wheat. S. nodorum produces numerous host-selective toxins (HSTs), all of which interact with dominant host sensitivity genes to cause disease. These host-toxin interactions are mirror images of classical gene-for-gene interactions. The effects of compatible host-toxin interactions in the development of SNB are largely additive, and they play important roles in disease susceptibility of seedlings as well as adult plants. One of the first S. nodorum HSTs was SnToxA,which was recently involved in a lateral transfer from S. nodorum to the tan spot pathogen. The map-based cloning of the Tsn1 locus on chromosome 5B, which confers sensitivity to SnToxA, reveals a complex evolutionary history of the locus when compared to rice, Brachypodium, and the homoeologous region of chromosome 5A. The isolation of Tsn1 will allow the molecular characterization of interactions in the wheat-S. nodorum pathosystem, which may be an excellent toxinbased model for other necrotrophic pathosystems.