ABSTRACT
Wheat-biotroph interactions often follow a classical gene-for-gene model, which was first described by Flor using the flax-rust system. In the classical gene-for-gene model, the pathogen-derived avirulence factors are recognized directly or indirectly by the products of the corresponding host resistance gene, resulting in a cascade of events that leads to a resistance response. Recognition of a pathogen-produced effector by a corresponding plant resistance gene, which are often nucleotide-binding, leucine-rich-repeat genes, initiates the plant immune response known as effector-triggered immunity. The SnTox1-Snn1 interaction was the first NE-sensitivity gene interaction to be identified and was later molecularly fully characterized in the wheat-P. nodorum system. Transcription analysis showed that in planta, expression of SnTox1 peaked at 72 h post inoculation, correlating with the onset of necrosis at the same time point. The ToxA-Tsn1 interaction has been the most intensively studied NE-susceptibility gene interaction in any wheat-necrotrophic pathosystem.
