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Molecular characterisation of Eucalyptus grandis PGIP

Dissertation (MSc)--University of Pretoria, 2003.

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Other Authors: Wingfield, Brenda D.
Format: Thesis
Published: University of Pretoria 2013
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access_status_str Open Access
author2 Wingfield, Brenda D.
author_browse Wingfield, Brenda D.
author_facet Wingfield, Brenda D.
collection Thesis
dc_rights_str_mv © 2003 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 Dissertation (MSc)--University of Pretoria, 2003.
format Thesis
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institution University of Pretoria (South Africa)
last_indexed 2026-06-10T12:38:10.802Z
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provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2013
publishDateRange 2013
publishDateSort 2013
publisher University of Pretoria
publisherStr University of Pretoria
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source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/24370 Molecular characterisation of Eucalyptus grandis PGIP Wingfield, Brenda D. Berger, David Kenneth Chimwamurombe, P.M. (Percy Maruwa) Wingfield, Michael J. Bhoora, Raksha Vasantrai Eucalyptus grandis genetic engineering Nicotiana genetic engineering Plant-pathogen relationships Eucalyptus grandis diseases and pests cotrol Nicotiana genetic engineering Coniophoraceae Antitfungal agents UCTD Dissertation (MSc)--University of Pretoria, 2003. Coniothyrium zuluense is the causal agent of a serious Eucalyptus stem canker disease in South Africa (Wingfield et al., 1997). Eucalypts are the most important hardwood plantations in the world, and in South Africa these hardwoods occupy approximately 1.5 million hectares of plantation area, an area that is soon to be increased by an additional 600 000 hectares. As exotics, Eucalyptus plantations are constantly exposed to infection by fungal pathogens such as C. zuluense, which by secreting cell-¬wall degrading enzymes contribute to the degradation of plant cell walls and subsequent reduction and in the quality of timber produced. This ultimately affects the South African paper, pulp and timber industries. Selection of resistant clones through traditional breeding methods is the most common method currently employed in overcoming the problem of fungal infection. The genetic manipulation of Eucalyptus trees for enhanced resistance to fungal diseases is an alternative to the time-consuming and tedious approach of conventional breeding. The identification of several antifungal proteins, particularly polygalacturonase-inhibiting proteins (PGIPs) from various plant species including Eucalyptus, lead to the hypothesis that over-expression of these proteins could potentially reduce pathogen attack. However, prior to the expression of PGIPs in plants, isolation and molecular characterization of these genes are required. The aims of this study were therefore (l) to clone and characterize the complete Eucalyptus grandis pgip gene, (2) to transform Nicotiana tabacum (tobacco) plants with the E. grandis pgip gene and (3) to test for inhibition of C. zuluense PGs by PGIPs extracted from transgenic tobacco plants. This forms the first step towards the generation of E. grandis clones that are more disease tolerant. A review of the role of fungal endopolygalacturonases and polygalacturonase¬inhibitors in plant-pathogen interactions are presented in chapter I. Strategies employed to isolate and characterize pgip genes from a range of plant species are highlighted and the importance ofPGIPs in disease resistance is discussed. In chapter 2, the molecular cloning and characterization of the E. grandis pgip gene is discussed. The work presented in this chapter is a follow up on work previously conducted by Chimwamurombe (2001). Previously, a partial Eucalyptus pgip gene sequence was obtained with the use of degenerate oligonucleotide primers. In this study, the complete Eucalyptus pgip gene was obtained through the employment of genome walking strategies. Transformation of Nicotiana tabacum cv LA Burley plants with the Eucalyptus pgip gene and the molecular characterization of transgenic tobacco plants is discussed in chapter 3. The transformation and expression of foreign genes in tobacco plants is a well-established protocol, making tobacco the most appropriate candidate plant for assessing the functionality of the plant transformation construct. The production of endopolygalacturonases from virulent C. zuluense isolates and the subsequent PGIP assays conducted to determine levels of PG inhibition are included in this chapter. This thesis consists of three independent chapters representing studies on the molecular characterization of an E. grandis pgip gene and focusing on the potential for inhibition of PGs produced by C. zuluense by Eucalyptus PGIP extracted from transgenic tobacco plants. Repetition of certain aspects in the individual chapters has been unavoidable and the thesis is presented following a uniform style. Genetics Unrestricted 2013-09-06T17:19:28Z 2005-05-19 2013-09-06T17:19:28Z 2004-04-24 2003 2005-05-06 Dissertation Bhoora, R 2003, Molecular characterization of Eucalyptys grandis PGIP, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/24370 > H956/ag http://hdl.handle.net/2263/24370 http://upetd.up.ac.za/thesis/available/etd-05062005-120449/ © 2003 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/pdf application/pdf application/pdf application/pdf application/pdf University of Pretoria
spellingShingle Eucalyptus grandis genetic engineering
Nicotiana genetic engineering
Plant-pathogen relationships
Eucalyptus grandis diseases and pests cotrol
Nicotiana genetic engineering
Coniophoraceae
Antitfungal agents
UCTD
Molecular characterisation of Eucalyptus grandis PGIP
title Molecular characterisation of Eucalyptus grandis PGIP
title_full Molecular characterisation of Eucalyptus grandis PGIP
title_fullStr Molecular characterisation of Eucalyptus grandis PGIP
title_full_unstemmed Molecular characterisation of Eucalyptus grandis PGIP
title_short Molecular characterisation of Eucalyptus grandis PGIP
title_sort molecular characterisation of eucalyptus grandis pgip
topic Eucalyptus grandis genetic engineering
Nicotiana genetic engineering
Plant-pathogen relationships
Eucalyptus grandis diseases and pests cotrol
Nicotiana genetic engineering
Coniophoraceae
Antitfungal agents
UCTD
url http://hdl.handle.net/2263/24370
http://upetd.up.ac.za/thesis/available/etd-05062005-120449/