Abiotic stresses are one of the major limiting factors of plant growth and thus
crop productivity. Exposure to these stresses, including temperature and UV, cause
physiological and epigenetic changes in plants. Such changes may be inherited in the
progeny of stressed plants, and may change their ability to respond to stress. To
understand the ability of plants to inherit an epigenetic stress memory as well as the
physiological manifestations of such a memory, we propagated both stressed and control
plants and compared the progeny under both normal and stressed conditions. In addition
to wild-type plants we used Dicer-like mutants dcl2, dcl3 and dcl4, as Dicers have been
linked to RNA-directed DNA methylation, a form of epigenetic memory. These studies
revealed that leaf number decreases in the progeny of stressed plants, and bolting occurs
earlier in the progeny of temperature stressed plants but later in the progeny of UV-C
stressed plants. Transposons were also re-activated in the progeny of stressed plants.
While heat shock transcription factor 2A increased expression in the progeny of heat
stressed plants, many genes involved in DNA repair and histone modifications decreased.
DCL2 and DCL3 appeared to be more important in transgenerational stress memory than
DCL4. However, all dcl plants were generally not significantly different than wild-type
plants, indicating that a single DCL deficiency may be compensated for by another DCL. / xiv, 246 leaves : ill. ; 29 cm
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:ALU.w.uleth.ca/dspace#10133/3311 |
| Date | January 2012 |
| Creators | Migicovsky, Zoë |
| Contributors | Kovalchuk, Igor |
| Publisher | Lethbridge, Alta. : University of Lethbridge, Dept. of Biological Sciences, c2012, Arts and Science, Department of Biological Sciences |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | en_CA |
| Detected Language | English |
| Type | Thesis |
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