Winter wheat (<i>Triticum aestivum</i> L.), seeded in the fall, cold acclimates when exposed to low fall temperatures. Growth resumes in spring, culminating in early summer harvest. Winter wheat yield is generally 20-25% higher than spring wheat. However, winter damage/kill can reduce its yield. A better understanding of the cold acclimation/tolerance process could help in the development of improved breeding strategies for winter wheat hardiness. Transcriptional activators and specific cold regulated (COR) genes are induced as a result of exposure to low temperatures. Thus, the objective of this study was to determine the quantitative expression of three COR genes (Wcs120, Wcor410 and Wcor14b) and one transcriptional activator (WCBF1) in field-grown wheat using real-time PCR and to establish any association with LT50 (temperature at which 50% of plants are killed). Winter Norstar (vrn-A1/vrn-A1), spring Manitou (Vrn-A1/Vrn-A1) and two near-isogenic lines (Spring Norstar (Vrn-A1/vrn-A1) and Winter Manitou (vrn-A1/vrn-A1), respectively) were used in these studies. Plants were sampled on three dates (Sept. 29, Oct. 12 and Oct. 26) in the fall of 2004. Accumulation of WCBF1 transcripts was highest in Norstar, but in all four genotypes there was an increase in transcripts by the second sampling date, followed by a decline on the third sampling date. Wcs120 transcripts increased from the first to the third sampling date in Norstar, Spring Norstar and Winter Manitou, but increased to the second sampling date and decreased by the third in Manitou. For Wcor14b, generally there was an increase to the second sampling date, followed by a decrease or steady levels on the third. Wcor410 showed a similar pattern, except for Spring Norstar wherein transcript levels increased by the third sampling date. With the exception of Wcor410 in Manitou, the Vrn-A1 locus affected gene expression in all genotypes. However, only Wcs120 expression followed the low-temperature tolerance pattern in these genotypes.
| Identifer | oai:union.ndltd.org:USASK/oai:usask.ca:etd-04012007-205644 |
| Date | 02 April 2007 |
| Creators | Denesik, Tyrel Jonathan |
| Contributors | Van Kessel, Andrew G., Pozniak, Curtis J., Gray, Gordon R., Fowler, Brian, Coulman, Bruce E., Chibbar, Ravindra N. |
| Publisher | University of Saskatchewan |
| Source Sets | University of Saskatchewan Library |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://library.usask.ca/theses/available/etd-04012007-205644/ |
| 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 of Saskatchewan 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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