Seed dormancy is a rest period of a seed by which plants can overcome unfavourable environmental conditions which do not allow the plant to fulfil its life cycle. Sugars are known to act as signalling molecules that control metabolism, growth and development in all phases of the plant life cycle. At first sight seed dormancy and sugar sensing seem two very different independent processes. However there are several indications in literature that sugar sensing and dormancy are strongly linked. Also our results indicated a link between these two processes. We subjected both seed dormancy and sugar sensing to quantitative trait loci analyses using naturally occurring variation that exists in recombinant inbred line populations. This lead to the identification of eleven seed dormancy and nine sugar sensing loci. Several of these loci co-localize. For one of these loci it has been proven that both traits are actually controlled by the same gene DOG1/GSQ5.
The extend of the link between both processes and how these processes are linked is still an important research question. To unravel this we propose to study the co-location between the seed dormancy and sugar sensing loci in more detail. Therefore we aim at the cloning of three additional loci in order to determine if indeed also here the same gene controls both traits. This would clarify the extend of the link. Furthermore, we would like to unravel the molecular mechanism of the DOG1/GSQ5 locus since this has been remained unknown. We think that combining knowledge of both research fields (seed biology and sugar sensing) might lead to the identification of the underlying mechanism, which will have significant impact in both fields.
Keywords: seed dormancy – sugar sensing – natural variation