Yellow rust disease is one of the most important problems in wheat production. It causes substantial
yield losses throughout the world. There are resistant and susceptible wheat varieties to various
yellow rust pathotypes. In this thesis genes that are induced in wheat, in virulence and avirulence
conditions upon yellow rust inoculations were investigated. Consequently, it was aimed to identify
genes that may be playing critical roles in the disease resistance mechanism. The strategy was to
construct subtracted cDNA libraries from resistant and susceptible plants and analyse the sequences
obtained from these libraries. The subtraction approach in this study differs from the common
subtraction designs implicated in plant-pathogen interactions / instead of comparing a compatible or
an incompatible interaction with a control, one of the subtractions in this study is done taking a
compatible interaction as the tester and an incompatible one as the driver, and the second
subtraction, vice versa. Therefore, it was intended to compare the transcriptomes from compatible
and incompatible plant-pathogen interactions directly.
Suppression Subtractive Hybridization method was used to construct subtracted cDNA libraries.
Two subtractions were performed / SSH1 (D-R), taking a compatible interaction as the tester sample
and an incompatible one as the driver sample, and SSH2 (R-D), taking an incompatible interaction
as the tester sample and a compatible one as the driver. In the end, two subtracted cDNA libraries,
SSH1 (D-R) library (1536 clones) and SSH2 (R-D) library (1152 clones) were obtained and the
libraries were sequenced.
Sequence results were subjected to BlastN and BlastX analysis. We looked for a group of genes that
were frequently emphasized in plant disease related studies when we searched within the Blast N
homology results of the two libraries. We found out that 19 such genes are present in our libraries.
We discussed supposed induction of these genes in the interactions investigated in our study. The
fact that these genes were found to be present in our libraries enhances the reliability of our results
suggesting that the gene sequences we found indeed belong to genes differentially expressed in the
respective comparisons investigated in our study. As such, it also implies that other sequences that
were found similar to genes of known functions may represent candidate genes as subjects of further
studies investigating wheat-yellow rust interactions.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/3/12609069/index.pdf |
| Date | 01 November 2007 |
| Creators | Celik, Ilay |
| Contributors | Akkaya, Mahinur |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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