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Effector identification from the susceptible Exserohilum turcicum – Zea mays interaction

Thesis (PhD)--University of Pretoria, 2019.

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Other Authors: Crampton, Bridget Genevieve
Format: Thesis
Language:English
Published: University of Pretoria 2020
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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