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Thesis (PhD)--University of Pretoria, 2019.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2020
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| _version_ | 1867613589311848448 |
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| access_status_str | Open Access |
| author2 | Crampton, Bridget Genevieve |
| author_browse | Crampton, Bridget Genevieve |
| author_facet | Crampton, Bridget Genevieve |
| collection | Thesis |
| dc_rights_str_mv | © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Thesis (PhD)--University of Pretoria, 2019. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/72846 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:38:33.011Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2020 |
| publishDateRange | 2020 |
| publishDateSort | 2020 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/72846 Effector identification from the susceptible Exserohilum turcicum – Zea mays interaction Crampton, Bridget Genevieve miekie.human@up.ac.za Berger, David Kenneth Human, Maria Petronella Plant-pathogen interactions Effector biology Population genetics UCTD Natural and agricultural sciences theses SDG-02 Natural and agricultural sciences theses SDG-09 Natural and agricultural sciences theses SDG-15 Thesis (PhD)--University of Pretoria, 2019. Exserohilum turcicum is the hemibiotrophic causal agent of Northern leaf blight of maize and sorghum. Despite the global importance of this yield-limiting pathogen, knowledge regarding genes contributing to disease development and race-specificity is limited. Therefore, this study aimed to identify genes involved in host colonization during biotrophic and necrotrophic phases of infection, as well as race-specific differences in gene expression. RNAseq of maize seedlings inoculated with a race 13N or 23N E. turcicum isolate was conducted to identify genes contributing to fungal pathogenicity, and expression was validated for four effector candidates. A population genetic study was undertaken of isolates from maize and sorghum to select isolates for sequencing of three putative effectors. Fungal biomass positively correlated with the percentages of E. turcicum reads mapped and indicated a lifestyle switch from biotrophy to necrotrophy between 7 and 13 dpi. Transcriptome sequencing enabled identification of cell wall degrading enzymes, peptidase-encoding genes, secondary metabolite biosynthesis genes and candidate effectors likely contributing to the pathogenicity of E. turcicum. Profiling of Ecp6 and candidate effector SIX13-like revealed increased expression at 5 and 7 dpi compared to 2 and 13 dpi. Evidence of host specificity was obtained from microsatellite haplotypes and sequencing of SIX13-like. Identification of candidate effector SIX13-like is consistent with the colonization of E. turcicum through the xylem of susceptible hosts and possibly indicates specificity of E. turcicum to either maize or sorghum. This study identified E. turcicum genes putatively involved in pathogenicity and describes a hypothetical model of the E. turcicum – maize interaction. The financial assistance of the National Research Foundation (NRF South Africa, grant unique numbers 85847, 88785, 92762 and 93671) toward this research is hereby acknowledged. Opinions expressed and conclusions arrived at, are those of the authors and are not necessarily to be attributed to the NRF. bs2026 Plant Science PhD Unrestricted SDG-02: Zero hunger SDG-09: Industry, innovation and infrastructure SDG-15: Life on land 2020-01-21T06:21:41Z 2020-01-21T06:21:41Z 2020-04 2019 Thesis Human, MP 2019, Effector identification from the susceptible Exserohilum turcicum – Zea mays interaction, PhD Thesis, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/72846> A2020 http://hdl.handle.net/2263/72846 en © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/octet-stream application/pdf University of Pretoria |
| spellingShingle | Plant-pathogen interactions Effector biology Population genetics UCTD Natural and agricultural sciences theses SDG-02 Natural and agricultural sciences theses SDG-09 Natural and agricultural sciences theses SDG-15 Effector identification from the susceptible Exserohilum turcicum – Zea mays interaction |
| title | Effector identification from the susceptible Exserohilum turcicum – Zea mays interaction |
| title_full | Effector identification from the susceptible Exserohilum turcicum – Zea mays interaction |
| title_fullStr | Effector identification from the susceptible Exserohilum turcicum – Zea mays interaction |
| title_full_unstemmed | Effector identification from the susceptible Exserohilum turcicum – Zea mays interaction |
| title_short | Effector identification from the susceptible Exserohilum turcicum – Zea mays interaction |
| title_sort | effector identification from the susceptible exserohilum turcicum zea mays interaction |
| topic | Plant-pathogen interactions Effector biology Population genetics UCTD Natural and agricultural sciences theses SDG-02 Natural and agricultural sciences theses SDG-09 Natural and agricultural sciences theses SDG-15 |
| url | http://hdl.handle.net/2263/72846 |