Heterologous Expression of the Pyrenophora tritici-repentis Effector Proteins ToxA and ToxB, and the Prevalence of Effector Sensitivity in Australian Cereal Crops
Here, we evaluate the expression of the proteinaceous effectors ToxA and ToxB, produced by the necrotrophic fungal pathogen Pyrenophora tritici-repentis, which confer tan spot disease susceptibility on wheat. These necrotrophic effectors were expressed in two heterologous systems: Escherichia coli a...
| Main Authors: | , , , |
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| Format: | Journal Article |
| Language: | English |
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FRONTIERS MEDIA SA
2019
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| Online Access: | http://hdl.handle.net/20.500.11937/75213 |
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| author | Moffat, Caroline See, Pao Theen Iagallo, Elyce M Oliver, Richard P |
| author_facet | Moffat, Caroline See, Pao Theen Iagallo, Elyce M Oliver, Richard P |
| author_sort | Moffat, Caroline |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Here, we evaluate the expression of the proteinaceous effectors ToxA and ToxB, produced by the necrotrophic fungal pathogen Pyrenophora tritici-repentis, which confer tan spot disease susceptibility on wheat. These necrotrophic effectors were expressed in two heterologous systems: Escherichia coli and Pichia pastoris. The E. coli SHuffle system was demonstrated to be superior to P. pastoris in generating high-levels of recombinant proteins that were soluble and stable. In addition, protein extracts from P. pastoris induced non-specific chlorosis on wheat, postulated to be caused by co-purified glucanases secreted by the host. Up to 79.6 μg/ml of ToxB was obtained using the SHuffle system in the absence of the native signal peptide, whilst the ToxA yield was considerably lower at 3.2 μg/ml. Results indicated that a histidine tag at the ToxA C-terminus interfered with effector functionality. Heterologously expressed ToxA and ToxB were tested on a panel of Australian cereals, including 122 varieties of bread wheat, 16 durum, 20 triticale and 5 barley varieties, as well as common plant model species including tobacco and Arabidopsis thaliana. A varying degree of effector sensitivities was observed, with a higher ToxB sensitivity and prevalence in the durum and triticale varieties. ToxB-induced chlorosis was also detected on barley. The heterologous expression of effectors that are easily scalable, will facilitate effector-assisted selection of varieties in wheat breeding programs as well as the investigation of P. tritici-repentis effectors in host and non-host interactions. |
| first_indexed | 2025-11-14T11:03:45Z |
| format | Journal Article |
| id | curtin-20.500.11937-75213 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:03:45Z |
| publishDate | 2019 |
| publisher | FRONTIERS MEDIA SA |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-752132019-04-09T06:11:50Z Heterologous Expression of the Pyrenophora tritici-repentis Effector Proteins ToxA and ToxB, and the Prevalence of Effector Sensitivity in Australian Cereal Crops Moffat, Caroline See, Pao Theen Iagallo, Elyce M Oliver, Richard P Science & Technology Life Sciences & Biomedicine Microbiology protein expression tan spot Pyrenophora tritici-repentis necrotrophic effector ToxA ToxB wheat yellow spot HOST-SELECTIVE TOXINS TAN SPOT PTR TOXB NECROTROPHIC EFFECTORS ESCHERICHIA-COLI 5 RACES WHEAT GENE NODORUM LOCUS Here, we evaluate the expression of the proteinaceous effectors ToxA and ToxB, produced by the necrotrophic fungal pathogen Pyrenophora tritici-repentis, which confer tan spot disease susceptibility on wheat. These necrotrophic effectors were expressed in two heterologous systems: Escherichia coli and Pichia pastoris. The E. coli SHuffle system was demonstrated to be superior to P. pastoris in generating high-levels of recombinant proteins that were soluble and stable. In addition, protein extracts from P. pastoris induced non-specific chlorosis on wheat, postulated to be caused by co-purified glucanases secreted by the host. Up to 79.6 μg/ml of ToxB was obtained using the SHuffle system in the absence of the native signal peptide, whilst the ToxA yield was considerably lower at 3.2 μg/ml. Results indicated that a histidine tag at the ToxA C-terminus interfered with effector functionality. Heterologously expressed ToxA and ToxB were tested on a panel of Australian cereals, including 122 varieties of bread wheat, 16 durum, 20 triticale and 5 barley varieties, as well as common plant model species including tobacco and Arabidopsis thaliana. A varying degree of effector sensitivities was observed, with a higher ToxB sensitivity and prevalence in the durum and triticale varieties. ToxB-induced chlorosis was also detected on barley. The heterologous expression of effectors that are easily scalable, will facilitate effector-assisted selection of varieties in wheat breeding programs as well as the investigation of P. tritici-repentis effectors in host and non-host interactions. 2019 Journal Article http://hdl.handle.net/20.500.11937/75213 10.3389/fmicb.2019.00182 English http://creativecommons.org/licenses/by/4.0/ FRONTIERS MEDIA SA fulltext |
| spellingShingle | Science & Technology Life Sciences & Biomedicine Microbiology protein expression tan spot Pyrenophora tritici-repentis necrotrophic effector ToxA ToxB wheat yellow spot HOST-SELECTIVE TOXINS TAN SPOT PTR TOXB NECROTROPHIC EFFECTORS ESCHERICHIA-COLI 5 RACES WHEAT GENE NODORUM LOCUS Moffat, Caroline See, Pao Theen Iagallo, Elyce M Oliver, Richard P Heterologous Expression of the Pyrenophora tritici-repentis Effector Proteins ToxA and ToxB, and the Prevalence of Effector Sensitivity in Australian Cereal Crops |
| title | Heterologous Expression of the Pyrenophora tritici-repentis Effector Proteins ToxA and ToxB, and the Prevalence of Effector Sensitivity in Australian Cereal Crops |
| title_full | Heterologous Expression of the Pyrenophora tritici-repentis Effector Proteins ToxA and ToxB, and the Prevalence of Effector Sensitivity in Australian Cereal Crops |
| title_fullStr | Heterologous Expression of the Pyrenophora tritici-repentis Effector Proteins ToxA and ToxB, and the Prevalence of Effector Sensitivity in Australian Cereal Crops |
| title_full_unstemmed | Heterologous Expression of the Pyrenophora tritici-repentis Effector Proteins ToxA and ToxB, and the Prevalence of Effector Sensitivity in Australian Cereal Crops |
| title_short | Heterologous Expression of the Pyrenophora tritici-repentis Effector Proteins ToxA and ToxB, and the Prevalence of Effector Sensitivity in Australian Cereal Crops |
| title_sort | heterologous expression of the pyrenophora tritici-repentis effector proteins toxa and toxb, and the prevalence of effector sensitivity in australian cereal crops |
| topic | Science & Technology Life Sciences & Biomedicine Microbiology protein expression tan spot Pyrenophora tritici-repentis necrotrophic effector ToxA ToxB wheat yellow spot HOST-SELECTIVE TOXINS TAN SPOT PTR TOXB NECROTROPHIC EFFECTORS ESCHERICHIA-COLI 5 RACES WHEAT GENE NODORUM LOCUS |
| url | http://hdl.handle.net/20.500.11937/75213 |