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SnTox5-Snn5: A novel Stagonospora nodorum effector-wheat gene interaction and its relationship with the SnToxA-Tsn1 and SnTox3-Snn3-B1 interactions.
- Friesen, Timothy L., Chu, Chenggen, Xu, Steven S., Faris, Justin D.
- Molecular plant pathology 2012 v.13 no.9 pp. 1101
- Leptosphaeria nodorum, Triticum aestivum, chromosome mapping, chromosomes, epistasis, fungal diseases of plants, genes, host-pathogen relationships, mycotoxins, necrosis, pathogens, plant proteins, tetraploidy, wheat
- The Stagonospora nodorum-wheat interaction consists of multiple pathogen - produced necrotrophic effectors that interact directly or indirectly with specific host gene products to induce the disease Stagonospora nodorum blotch (SNB). Here, we used a tetraploid wheat mapping population to identify and characterize a sixth effector-host gene interaction in the wheat-S. nodorum system. Initial characterization of the effector, designated SnTox5, indicated that it is a proteinaceous necrotrophic effector that induces necrosis on host lines harboring the Snn5 sensitivity gene, which we mapped to the long arm of wheat chromosome 4B. Based on ultra-filtration, SnTox5 is likely in the size range of 10 to 30 kDa. Analysis of SNB development in the mapping population indicated that the SnTox5-Snn5 interaction explained from 37 to 63% of the variation, demonstrating that this interaction plays a significant role in disease development. The effects of a compatible SnTox5-Snn5 interaction were additive with those of a compatible SnToxA-Tsn1 interaction, and when the two interactions occurred together the level of SNB was significantly increased. However, the effects of SnTox5-Snn5 were epistatic to the SnTox3-Snn3-B1 interaction. Similar to several other interactions in this system, the SnTox5-Snn5 interaction is light dependent suggesting that multiple interactions may exploit the same pathways to cause disease.