Thesis (MSc)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: Ribosome inactivating proteins (RIPs) are potent toxins produced by a wide
range of evolutionarily diverse plants. These toxins cause cell death by physically
dismantling ribosomal RNA and shutting down protein synthesis. They also have
a strong antiviral activity. Some believe that the antiviral property of RIPs is a
function of ribosomal inactivation, others believe that the two properties are
unrelated. RIPs are non-specific in their antiviral activity. Transgenic RIPexpressing
plants are resistant to a wide spectrum of viruses. Many different
viruses threaten grapevine. It is not practical to design individual remedies for
each of these viruses. In this study, we screen the grapevine genome for the
presence of a RIP gene using degenerate PCR primers. If a RIP gene does exist
in grapevine, it is not being expressed in a useful way. We also clone several
well-documented RIP genes from various plants into pGEM-T Easy: dianthin
from Dianthus caryophyllus; p-Iuffin from Luffa octandra and mirabilis antiviral
protein (MAP) from Mirabilis jalapa. These isolated genes are then subcloned
into a selection of expression vectors: dianthin into pKK223-3, a bacterial
expression vector; p-Iuffin into pCambia3301, a plant expression vector; and
MAP into pFLAG, a yeast expression vector. The constructs prepared in this
project may be used for the synthesis of RIP molecules. The exogenous
application of RIPs has been shown to protect plants from viruses.
Transformation of grapevine with the RIP-containing plant expression vector may
result in a variety of vine that is resistant to a wide range viruses. This thesis
describes preliminary work in an attempt to impart broad-spectrum antiviral
resistance to grapevine. / AFRIKAANSE OPSOMMING: Ribosomale-inaktiverende proteïne (RIPs) is kragtige toksienes wat deur 'n wye
verskeidenheid evolusionêr diverse plante verskaf word. Hierdie toksienes
veroorsaak die dood van die selle deur fisies die ribosomale RNA af te breek en
proteïensintese stop te sit. Hulle toon ook 'n sterk antivirale aktiwiteit. Sommige
voel dat die antivirale eienskap van RIPs 'n funksie van ribosomale inaktivering
is, terwyl ander glo dat die twee eienskappe onafhanklik optree. RIPs is in hul
antivirale aktiwiteit onspesifiek. Transgeniese RIP-weergewende plante toon
weerstand teen 'n wye spektrum virusse. Wingerd word deur baie verskillende
virusse aangeval. Dit is onprakties om spesifieke teenmiddels vir elk van die
virusse te ontwerp. In hierdie studie word die wingerdgenoom vir die voorkoms
van 'n RIP-geen ondersoek, deur die gebruik van degeneratiewe PKR primers.
As daar wel 'n RIP-geen in wingerd voorkom, word dit nie in 'n nuttige manier
uitgedruk nie. Ons het ook 'n groep goedgedokumentêre RIP-gene vanuit
verskeie plante in pGEM- T Easy gekloneer: dianthin vanuit Dianthus
caryophyllus; p-Iuffin vanuit Luffa octandra; en mirabilis antivirale proteïen (MAP)
vanuit Mirabilis jalapa. Hierdie geïsoleerde gene is toe in verskeie
uitdrukkingsvektore gesubkloneer: dianthin in pKK223-3, 'n bakterïele
uitdrukkingsvektor; p-Iuffin in pCambia3301, 'n plant uitdrukkingsvektor; en MAP
in pFLAG, 'n gis uitdrukkingsvektor. Die constructs wat in hierdie projek voorberei
is, kan gebruik word vir die sintese van RIP molekules. Dit is gevind dat die
eksogeniese toepassing van RIPs plante teen virus-infeksie beskerm. Die
transformasie van wingerd met die RIP-bevattende plant ekspressievektor kan 'n
wingerd wat teen 'n wye verskeidenheid virusse bestand is tot stand bring.
Hierdie tesis beskryf die voorlopige werk in 'n poging om breë-spektrum antivirale
weerstand in wingerd deelagtig te maak.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/51803 |
| Date | 03 1900 |
| Creators | Wilsen, Kathleen L. (Kathleen Lucy) |
| Contributors | Burger, J. T., Stellenbosch University. Faculty of AgriSciences. Dept. of Genetics. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 114 p. : ill. |
| Rights | Stellenbosch University |
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