Evaluating the importance of the tan spot ToxA–Tsn1 interaction in Australian wheat varieties
The necrotrophic fungal pathogen Pyrenophora tritici-repentis (Ptr) causes the major wheat disease tan spot, and produces multiple necrotrophic effectors that contribute to virulence. The proteinaceous effector ToxA induces necrosis in wheat genotypes possessing the Tsn1 gene, although the importanc...
| Main Authors: | , , , , |
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| Format: | Journal Article |
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Wiley-Blackwell
2018
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| Online Access: | http://hdl.handle.net/20.500.11937/68198 |
| _version_ | 1848761769225355264 |
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| author | See, Pao Theen Marathamuthu, K. Iagallo, E. Oliver, Richard Moffat, Caroline |
| author_facet | See, Pao Theen Marathamuthu, K. Iagallo, E. Oliver, Richard Moffat, Caroline |
| author_sort | See, Pao Theen |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The necrotrophic fungal pathogen Pyrenophora tritici-repentis (Ptr) causes the major wheat disease tan spot, and produces multiple necrotrophic effectors that contribute to virulence. The proteinaceous effector ToxA induces necrosis in wheat genotypes possessing the Tsn1 gene, although the importance of the ToxA–Tsn1 interaction itself in varietal disease development has not been well studied. Here, 40 Australian spring wheat varieties were assessed for ToxA sensitivity and disease response to a race 1 wildtype Ptr isolate and ToxA-deleted strain at both seedling and tillering growth stages. ToxA sensitivity was generally associated with disease susceptibility, but did not always predict spreading necrotic symptoms. Whilst the majority of Tsn1 varieties exhibited lower disease scores following toxa mutant infection, several exhibited no distinct differences between wildtype and toxa symptoms. This implies that ToxA is not the major determinant in tan spot disease development in some host backgrounds and indicates the presence of additional effectors. Unexpectedly, several tsn1 varieties exhibited a reduction in disease severity following toxa mutant inoculation, which may suggest an indirect role for ToxA in pathogen fitness. Additionally, increased chlorosis was observed following toxa mutant infection in three varieties, and further work is required to determine whether this is likely to be due to ToxA epistasis of ToxC symptoms. Taken together, these observations demonstrate that Ptr interacts with the host in a complex and intricate manner, leading to a variety of disease reactions that are dependent or independent of the ToxA–Tsn1 interaction. |
| first_indexed | 2025-11-14T10:36:56Z |
| format | Journal Article |
| id | curtin-20.500.11937-68198 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:36:56Z |
| publishDate | 2018 |
| publisher | Wiley-Blackwell |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-681982018-11-29T06:27:13Z Evaluating the importance of the tan spot ToxA–Tsn1 interaction in Australian wheat varieties See, Pao Theen Marathamuthu, K. Iagallo, E. Oliver, Richard Moffat, Caroline The necrotrophic fungal pathogen Pyrenophora tritici-repentis (Ptr) causes the major wheat disease tan spot, and produces multiple necrotrophic effectors that contribute to virulence. The proteinaceous effector ToxA induces necrosis in wheat genotypes possessing the Tsn1 gene, although the importance of the ToxA–Tsn1 interaction itself in varietal disease development has not been well studied. Here, 40 Australian spring wheat varieties were assessed for ToxA sensitivity and disease response to a race 1 wildtype Ptr isolate and ToxA-deleted strain at both seedling and tillering growth stages. ToxA sensitivity was generally associated with disease susceptibility, but did not always predict spreading necrotic symptoms. Whilst the majority of Tsn1 varieties exhibited lower disease scores following toxa mutant infection, several exhibited no distinct differences between wildtype and toxa symptoms. This implies that ToxA is not the major determinant in tan spot disease development in some host backgrounds and indicates the presence of additional effectors. Unexpectedly, several tsn1 varieties exhibited a reduction in disease severity following toxa mutant inoculation, which may suggest an indirect role for ToxA in pathogen fitness. Additionally, increased chlorosis was observed following toxa mutant infection in three varieties, and further work is required to determine whether this is likely to be due to ToxA epistasis of ToxC symptoms. Taken together, these observations demonstrate that Ptr interacts with the host in a complex and intricate manner, leading to a variety of disease reactions that are dependent or independent of the ToxA–Tsn1 interaction. 2018 Journal Article http://hdl.handle.net/20.500.11937/68198 10.1111/ppa.12835 http://creativecommons.org/licenses/by/4.0/ Wiley-Blackwell fulltext |
| spellingShingle | See, Pao Theen Marathamuthu, K. Iagallo, E. Oliver, Richard Moffat, Caroline Evaluating the importance of the tan spot ToxA–Tsn1 interaction in Australian wheat varieties |
| title | Evaluating the importance of the tan spot ToxA–Tsn1 interaction in Australian wheat varieties |
| title_full | Evaluating the importance of the tan spot ToxA–Tsn1 interaction in Australian wheat varieties |
| title_fullStr | Evaluating the importance of the tan spot ToxA–Tsn1 interaction in Australian wheat varieties |
| title_full_unstemmed | Evaluating the importance of the tan spot ToxA–Tsn1 interaction in Australian wheat varieties |
| title_short | Evaluating the importance of the tan spot ToxA–Tsn1 interaction in Australian wheat varieties |
| title_sort | evaluating the importance of the tan spot toxa–tsn1 interaction in australian wheat varieties |
| url | http://hdl.handle.net/20.500.11937/68198 |