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A genomic approach to the ecology & evolution of seed dormancy - HH3402SX

Physiological seed dormancy is present throughout the higher plants and has a profound impact on many aspects of crop production and the conservation of genetic resources as well as the structure and development of plant communities in the natural environment. Despite this, there is considerable ignorance of how dormancy is controlled at the molecular level and this hampers the development of more efficient practices in crop production, ex situ genetic conservation and habitat creation and restoration. Greater understanding of seed dormancy therefore has considerable generic value. This project takes advantage of recent developments in genomics techniques to address this lack of understanding and to provide the basis for developing practically useful techniques relevant to a number of DEFRA’s objectives.

Sustainable production of safe food: Weed management is central to the cost and efficiency of production and therefore the amount of land required for production. More than 50 tonnes of herbicides are applied each year to horticultural crops alone. When these chemicals are not used or their application is reduced, the cost of weeding equipment and labour greatly increases, so that in organic systems weed control can account for as much as 50% of the variable costs of production. Dormancy optimises the distribution of weed emergence over time, and is therefore a key factor that allows weeds to escape control by chemical, cultural, mechanical, and biological measures. An improved understanding of seed dormancy is essential to providing new opportunities for weed control products and approaches to weed management.

Genetic resources conservation: There is considerable international effort directed towards ex situ conservation of plant species through the storage of their seeds in genebanks. For example, the DEFRA supported Millennium Seed Bank project aims to conserve the native UK flora and 10% of the World's flowering plants as seeds by 2010. An essential part of this genebank activity is to assess the quality of the collections including dormancy status, but there is currently no economic way to determine this.

Enhanced biodiversity in an attractive countryside: The success of pro-active techniques to enhance biodiversity, in both urban and farming environments, is often determined by the ability to establish and maintain the correct plant species balance as a framework to attract a diverse fauna and floral community. Seed dormancy is fundamental to such plant community dynamics and therefore has major ecological importance.

We will use well-characterised seed systems and Arabidopsis microarrays to compare gene expression in a range of Brassicacea species. This work will increase understanding of the mechanisms of dormancy to underpin and provide insights to the development of new weed control strategies and reduction of pesticide use in support of sustainable and safe food production. The improved understanding will aid in situ enhancement of biodiversity and will also contribute to more efficient ex-situ conservation by developing the basis of a practical test for dormancy status.

1. Characterise Arabidopsis seed lots and optimise sample preparation and hybridising conditions for microarray experiments
2. Identify gene expression patterns in Arabidopsis seeds in different physiological states using microarrays.
3. Identify gene expression patterns in Sisymbrium officinale and other Brassicacea in different physiological states using microarrays
4. Identify genes that are suitable as indicators of different physiological states by database searching and expression analysis of candidates in non-brassica species5. Develop the basis of a test for dormancy status by generating polyclonal antibodies to conserved peptide fragments and demonstrating their specificity and utility in western-blot analyses
Project Documents
• Final Report : A Genomic Approach to Understanding Seed Dormancy   (868k)
Time-Scale and Cost
From: 2003

To: 2007

Cost: £658,203
Contractor / Funded Organisations
Warwick - HRI, Horticulture Research International
Allocated - WHRI              
Organic Farming              
Sustainable Farming and Food              
Sustainable Production              
Fields of Study