The Sleeping Beauties research theme aims to increase our understanding of the complex nature of seed dormancy of wild plant species using the full power of the ‘omics’ technologies, to review dormancy classification schemes in under-researched families, particularly the orchids, and to assess how seed quality and germination kinetics contribute to species resilience in a changing environment.
Sisymbrium officinale seeds which are dormant remain intact when imbibed (left image) but when dormancy is released the seed coat ruptures (right image, arrow heads).
Global climate change has the potential to impact on two key aspects of the temperature regulation of regeneration in the natural environment: rate of dormancy loss/induction, and germination stimulation/inhibition. Under conditions of non-limiting water, temperature is the driver for both dormancy loss and germination in temperate and alpine floras. In addition, short term treatment with sub-optimal moisture for germination is known to invigorate seeds and enhance seedling performance. Thus we are developing:
- Thermal time models for a range of species and use these to compare and predict emergence patterns in situ.
- Molecular and biochemical markers for such quality traits and test these on seedlots for restoration purposes, particularly in Europe.
Classification of dormancy types is a valuable, practical means of describing a seed trait in relation to a predetermined set of environmental conditions, plant hormone applications, and given time intervals. To test how much one type of dormancy merges into another to challenge the assumption that the classes are discreet, we use:
- Dormancy markers to map responses onto the APG phylogeny and evolutionary pathways considered in relation to embryo morphologies.
- Complementary studies to assess the importance of epigenetics on seed dormancy.
Deng, W., Jeng, D-S., Toorop*, P.E., Squire, G.R., Iannetta, P.P.M. (2012) A mathematical model of plant mucilage expansion in myxospermous seeds of Capsella bursa-pastoris L. Medik. (shepherd’s purse). Annals of Botany 109: 419–427.
Mattana*, E., Pritchard*, H. W., Porceddu, M., Stuppy*, W. H., Bacchetta, G. (2012) Interchangeable effects of gibberellic acid and temperature on embryo growth, seed germination and epicotyl emergence in Ribes multiflorum ssp. sandalioticum (Grossulariaceae). Plant Biology 14: 77-87.
Newton*, R.J., Hay, F.R., Ellis, R.H. (2013) Seed development and maturation in early spring-flowering Galanthus nivalis and Narcissus pseudonarcissus continues post-shedding with little evidence of maturation in planta. Annals of Botany, doi:10.1093/aob/mct051.
Paulsen, T.R., Colville*, L., Kranner, I., Daws, M.I., Hogstedt, G., Vandvik, V., Thompson, K (2013) Physical dormancy in seeds: a game of hide and seek? New Phytologist 198: 496-503.
Toorop*, P.E., Campos Cuerva, R., Begg, G.S., Locardi, B., Squire, G.R., Iannetta, P.P.M. (2012) Co-adaptation of seed dormancy and flowering time in the arable weed Capsella bursa-pastoris (L.) Medik. (shepherd’s purse). Annals of Botany 109: 481–489.
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