Seed dormancy is an important trait refined by evolution, to aid survival in adverse environments and to time germination and thereby select the correct habitat and climate space for subsequent plant growth and reproduction. Depth of dormancy changes continuously in response to the environment surrounding the seed and is therefore a relative rather than an absolute condition. In nature, these changes are triggered by seasonally characteristic environmental signals that are integrated by the seed over time to select the optimum conditions for germination. The mechanisms by which environmental signals influence this dormancy cycling have been studied in the present work using a combination of eco-physiology and molecular biology. Two contrasting Arabidopsis thaliana ecotypes Cape Verdi Isle (Cvi) and Burren (Bur) have been compared. They are adapted to a hot dry (Cvi) and a cool damp (Bur) climate and exhibit winter and summer annual phenotypes respectively. Experimental work in the laboratory, controlled environment and field has focussed on the effect of temperature, light and nitrate during seed maturation and subsequent imbibition. The work was also extended to studying other life cycle events such as the transition from vegetative growth to reproductive growth, flowering and seed maturity. This work has extended our understanding of the responses of life cycle traits to environmental signals. However, climates are changing and further data was collected in a series of experiments in a unique thermal gradient tunnel to provide insight into the impact of predicted global warming scenarios on these traits. The results presented indicate the plasticity of the plant life cycle and the extent to which global warming might affect this in Arabidopsis, and how increased temperature is likely to affect different annual phenotypes.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:582397 |
| Date | January 2013 |
| Creators | Huang, Ziyue |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/57478/ |
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