People

Toorop, Peter

Job Title Molecular Biologist
Department Seed Conservation
Section Research
Science Teams Millennium Seed Bank Project
Joined Kew 2001
Foreign Language(s) Dutch (mother tongue), French (basic), German (basic).

Qualifications & Appointments

MSc (equivalent), Biology, Utrecht Univ., 1988

PhD (equivalent), Wageningen Univ., 1998.

Editorial Board, Seed Science Research

Correspondent, Dutch Institute for Biology.

Role

Molecular and genetic characterisation of seed quality.

Science management responsibility as member of Departmental Student Steering Committee and chair of Departmental science sector group. Raising funds through external grants, e.g. Defra, ARC. Regular reviewer of manuscripts for a range of peer-reviewed journals. Research involves assessment of the germination process, often based on the observation of radicle protrusion, which marks the end of germination. Dormancy, ageing and storage behaviour influence germination capacity of banked seeds, and fitness of these populations depends on their genetic variation. Parameters to assess these seed traits other than germination tests are not commonly available. One particularly poorly understood type of dormancy is physiological dormancy, which often cannot be broken easily resulting in inadequate accessions. Improving our knowledge of the molecular background of physiological dormancy contributes to a better assessment of seed quality. My interest lies in the molecular and physiological aspects of seed dormancy; cycling through induction and breaking of physiological seed dormancy; seed desiccation tolerance; seed ageing; genomics and proteomics as tools to better understand seed physiology; seed ageing; genetic diversity of seed populations in relation to seed physiological traits. Ultimately, improved understanding in these areas will lead to enhanced diagnostics tools.

Projects

A Genomic Approach to Understanding Seed Dormancy

A Novel Role for Phytochrome in Dormancy Release Inhibition

Does One Seed Collection Represent the Genetic Diversity of a Population? A Seed Harvest Study

Genetic Polymorphisms in Populations of Aesculus hippocastanum across Europe

Molecular and Biophysical Dissection of Changes in Dormancy in Seeds of Sisymbrium officinale and Arabidopsis thaliana

Proteome Responses to Desiccation in Talauma ovata Seeds

The Role of Nitrate in Breaking Dormancy

Theme: Diagnosis of Viability and Germination

Theme: Ecophysiology and Morphology

Theme: Genetics and Chemical Traits

Theme: Science of Ageing

Selected Publications 2001-2005

Ouyang, X., van Voorthuysen, T., Toorop, P. & Hilhorst, H. (2002). Seed vigor, aging, and osmopriming affect anion and sugar leakage during imbibition of maize (Zea mays L.) caryopses. International Journal of Plant Science 163: 107-112.

Toorop, P.E., Groot, S.P.C. & Hilhorst, H.W.M. (2003). Expression of a ribosomal protein gene during germination of cabbage (Brassica oleracea f. oleracea). In: Nicolás, G., Bradford, K.J., Côme, D., Pritchard, H.W.P. (eds) The biology of seeds. Proceedings Workshop on Seeds, Salamanca.

Amaral da Silva, E.A., Toorop, P.E., van Aelst, A.C. & Hilhorst, H.W.M. (2004). Abscisic acid controls embryo growth potential and endosperm cap weakening during coffee (Coffea arabica cv. Rubi) seed germination. Planta 220: 251-261.

Amaral da Silva, E.A., Toorop, P.E., Nijsse, J., Bewley, J.D. & Hilhorst, H.W.M. (2005). Exogenous gibberellins inhibit coffee (Coffea arabica cv. Rubi) seed germination and cause cell death in the embryo. Journal of Experimental Botany 56: 1029-1038.

Toorop, P.E., Barroco, R.M., Engler, G., Groot, S.P.C. & Hilhorst, H.W.M. (2005). Differentially expressed genes associated with dormancy or germination of Arabidopsis thaliana seeds. Planta 221: 637-647.

Cadman, C., Toorop, P.E., Hilhorst, H.W.M., Finch-Savage, W.S (2006). Title. The Plant Journal xx: pp-pp.

Finch-Savage, W.S., Cadman, C., Toorop, P.E., Lynn, J., Hilhorst, H.W.M. (2007). Title. The Plant Journal xx: pp-pp.

Selected Publications pre-2001

Toorop, P.E., Bewley, J.D. & Hilhorst, H.W.M. (1996). Endo-ß-mannanase isoforms are present in the endosperm of tomato seeds, but are not essentially linked to the completion of germination. Planta 200: 153-158.

Hilhorst, H.W.M. & Toorop, P.E. (1997). A review on dormancy, germinability and germination in crop and weed seeds. Advances in Agronomy 61: 111-165.

Toorop, P.E., van Aelst A.C. & Hilhorst, H.W.M. (1998). Endosperm cap weakening and endo-ß-mannanase activity during priming of tomato (Lycopersicon esculentum cv. Moneymaker) seeds are initiated upon crossing a threshold water potential. Seed Science Research 8: 483-491.

Toorop, P.E., Bewley, J.D., Abrams, S.R. & Hilhorst, H.W.M. (1999). Structure-activity studies with ABA analogs on germination and endo-ß-mannanase activity in tomato and lettuce seeds. Journal of Plant Physiology 154: 679-685.

Toorop, P.E., van Aelst, A.C. & Hilhorst, H.W.M. (2000). The second step of the biphasic endosperm cap weakening that mediates tomato (Lycopersicon esculentum) seed germination is under control of ABA. Journal of Experimental Botany 51: 1371-1379.