The interaction between wheat (Triticum aestivum) and the Russian
wheat aphid (Diuraphis noxia) was investigated on a molecular level. The
resistant cultivar, Tugela DN1, was infested with the Russian wheat aphid
and tissue harvested at 3 hour time intervals for 24 hours. Differential
display RT-PCR was used to clone genes that were inducibly expressed using
primers specific to the conserved subdomain VIb of the kinase domain of
protein kinases. Differentially expressed genes were found as early as three
hours after infestation. These fragments were cloned and sequenced.
A total of 11 differentially expressed cDNA fragments were analyzed.
Four showed homology to genes encoding proteins involved in normal
cellular metabolism, such as the Rubisco large subunit, indole-3-gylcerol
phosphate lyase that produces indole that could act as a volatile messenger
molecule, triose-phosphate isomerase that is involved in glycolysis and 2-isopropylmalate
synthase that is involved in leucine biosynthesis.
Of the other cDNAs, three clones showed homology to several
hypothetical proteins with no defined functions, while the other three
showed no homology at all with any other known genes.
One of the unknown clones (D20) was selected for further analysis.
The gene was inducibly expressed only in the infested resistant plants, but
not in the infested susceptible plants. The expression of the gene was
induced within 3 h after infestation reaching a maximum expression level 6
h.p.i. The gene is present as a single copy within the genomes of susceptible
and 5 different resistance lines. An attempt to clone the full length gene
was only partially successful since after the sequences were combined
homology was found with several hypothetical genes from rice and maize.
However, no identity and function could be given.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-07052005-135508 |
| Date | 05 July 2005 |
| Creators | Huang, Ju-Chi |
| Contributors | Dr B Visser, Prof AJ van der Westhuizen |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-07052005-135508/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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