The aim of the study was to learn more about the expression of b-1,3-glucanase during the
resistance response of wheat to the RWA (Diuraphis noxia)(Mordvilko).
The different resistance genes (Dn1, Dn2 and Dn5) used in the study would shed more light
on the possibility that b-1,3-glucanase expression is a universal biochemical resistance
mechanism with regard to RWA. Tugela DN (Dn1) and Dn2 plants resulted in a similar
expression pattern of b-1,3-glucanases after RWA infestation. The Dn1 and Dn2 cultivars had
very high differential b-1,3-glucanase activity induction, which occurred much sooner
compared to the infested susceptible plants. Wheat plants with the Dn5 resistance gene
induced b-1,3-glucanase activity to a much lower level compared to the other two resistant
lines.
Northern blot analyses confirmed that the increase in b-1,3-glucanase activity and peptide
levels in the Western blot analyses was due to increased transcription of b-1,3-glucanase
genes.
The induced b-1,3-glucanases were located intercellularly in the vascular bundle and
mesophyll cell walls of wheat leaves. Intracellular the b-1,3-glucanases were primarily
located in the chloroplast grana with low labelling found in the cytoplasm.
Chloroplasts were isolated and fractionated to scrutinize results obtained with the localisation
study. b-1,3-glucanase activity and Western blot analysis of chloroplast fractions verified
these results with a 35 kDa b-1,3-glucanase residing in the chloroplast membrane bound
fraction. These b-1,3-glucanases could play a role in the protection of the chloroplast of
infested resistant plants.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-08232005-143033 |
| Date | 23 August 2005 |
| Creators | Wilding, Willem Jacobus Marthinus |
| Contributors | Prof AJ van der Westhuizen, Dr B Visser |
| 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-08232005-143033/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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