Stephen Gleddie

Bsc. Hons Biology U. of O. 1978
Msc. Biology Carleton 1981
PhD. Biology Carleton 1984

Research Scientist, Agriculture and AgriFood Canada, Eastern Cereal and Oilseed Research Centre, Ottawa
Adjunct Professor, Biology Dept. Carleton University
Adjunct Professor, University of Guelph
Editor, Plant Cell Reports
Member, of the Research Advisory Board, Ottawa Bioprocessing Initiative
Member, Editorial Advisory Board, Canada Research Horizons (www.researchhorizons.com)

Research Interests

Plant proteomics, gene expression, protein engineering, and structure function of food allergens
Plant regeneration from single cells, tissues, and organs
Transgenic plant production and gene expression, protein targeting
Phage display of proteins, directed evolution and protein modification

Major Research Activities

Food-based Allergens
Human and animals exhibit allergic reactions to various food sources and we have sought to understand the nature of immune reactions in adults and juveniles to soybean proteins. The allergens are identified and characterized by standard gel-based protein separation and mass spectrometry methods. We are developing high-throughput methods to screen thousands of seeds to verify and characterize lines of soybean that may be lacking individual allergens-thereby paving the way to develop hypoallergenic varieties for the food and feed industries.

Plant pathogen interactions
We are using proteomics approaches (2D gel based, ICAT and iTRAC) to survey global protein differences between resistant and susceptible corn plants to the fungal pathogen Fusarium graminearum (causal agent of corn ear rot). This pathogen produces mycotoxins which affect plants, animals, and humans and limit the value and use of contaminated grains. We are using yeast as a model system to both overexpress potential resistance genes, and study the yeast ordered knock out populations to reveal details concerning resistance mechanisms.

Selected Publications:

Robert, L., Foster, L., Levesque-Lemay, M., Routly, E., Wilkinson, D., and Gleddie, S. 2004. The potential of limiting transgene flow by modifying the proteins on the surface of pollen grains. Plant Biotechnology Institute Bulletin, NRC, pp. 21-24, July 2004.
Ouellet, T., Harris, L., and Gleddie, S. 2004. Genomique structurale et fonctionnelle appliquee a la lutte phytosanitaire: le cas de la fusariose de l=epi chez les cereales. In: Enjeux phytosanitaires pour l=agriculture et l=environnement du XXIeme siecle, Ed. C. Regnault-Roger. Tec et Coc. Lavoisier, Paris, France-In Press.
Hegedus, D., Baldwin, D., O’Grady, M., Braun, L., Gleddie, S., Sharpe, A., Lydiate, D., and M. Erlandson. 2003. Midgut proteases from Mamestra configurata (Lepidoptera: Noctuidea) larvae: Characterization, cDNA cloning and expressed sequence tag analysis. Arch. Insect. Biochem. and Physiol. 53: 30-47.
Melo, F., Mello, M., Franco, O, Rigden, D., Mello,L., Genu, A., Silva-Filho, M., Gleddie, S., and M. Grossi-de-Sa. 2003. Use of phage display to select novel cystatins specific for Acanthoscelides obtectus cysteine proteinases. Biochimica Biophys Acta. 1651: 146-152.

Malik, K., Wu, K., Li, X-Q., Martin-Heller, T., Hu, T., Foster, E., Tian, L., Wang, C., Ward, K., Jordan, M., Brown, D., Gleddie, S., Simmonds, D., Zheng, S., Simmonds, J., and B. Miki. 2002. A constitutive gene expression system derived from the tCup cryptic promoter elements. Theor. Appl. Genetics. 105: 505-514.
Hegedus, D., O’Grady, M., Chamankhah, M., Baldwin, D., Gleddie, S., Braun, L., and M. Erlandson. 2002. Changes in cysteine protease activity and localization during midgut metamorphosis in the crucifer root maggot (Delia radicum). Insect Biochem. Mol. Biol. 32: 1585-1596.
Foster, E., Schneiderman, D., Cloutier, M., Gleddie, S. and L. Robert. 2002. Modifying the pollen coat protein composition in Brassica. The Plant Journal. 31: 477-486.
Foster, E., Gleddie, S., and Robert L. 2001. Tapetal gene expression reflects the complex role of the tapetum in pollen development. Recent Res. Devel. Plant Physiology 2: 219-239.
Harris, L.J., and Gleddie, S. 2001. A modified RpL3 gene from rice confers tolerance of the Fusarium graminearum mycotoxin deoxynivalenol totransgenic tobacco. Physiological and Molecular Plant Pathology 58: 173-181.
Gleddie, S., and Michaud, D. 2000. The control of plant pathogens with protease inhibitors: A realistic approach? In: Recombinant Protease inhibitors in Plants, Ed. D. Michaud. Published by Landes Bioscience Austin, Texas. pp. 53-64.

Recent Presentations:

Gleddie, S., Hermans, A., Dubuc, E., and C. Lorbetskie. 2004. Directed evolution and the selection of superior cysteine protease inhibitors using phage display. Proceedings of the 4th International Conference of the Canadian Proteomics Initiative p. , May 14-16, 2004, Montreal, Quebec.
Gleddie, S., Harris, L., Dubuc, E., and Gagnon, C. 2004. Amino acid substitutions at position 255 in the yeast ribosomal protein L3 affect growth rate and mycotoxin sensitivity. Proceedings of the 4th International Conference of the Canadian Proteomics Initiative p.64, May 14-16, 2004, Montreal, Quebec.
Gagnon, C., and Gleddie, S. 2004. Indentification of major soybean allergens by 2D immunoblot analysis. Proceedings of the 4th International Conference of the Canadian Proteomics Initiative p.100, May 14-16, 2004, Montreal, Quebec.
Anoop, V., Lindsay, K., Harris, L., and Gleddie, S. 2004. Functional proteomics of Fusarium-corn interactions to identify novel proteins associated with the Fusarium resistance. Proceedings of the 4th International Conference of the Canadian Proteomics Initiative p.57, May 14-16, 2004, Montreal, Quebec.

Patents:

Gleddie, S., and Robert, L. 1999. Protein expression in floral cells. US patent application no. 60,078,728. and PCT application no. CA99,00237.
Bate, N., Hegedus, D., Schafer, R., and Gleddie, S.1999. Hydrogen peroxide lyase regulatory region. US patent application no. 10,204,234 and PCT application no. 01271445.7.
Harris, L., and Gleddie, S. 2000.Tolerance of trichothecene mycotoxins in plants and animals through the modification of the peptidyl transferase gene. Issued US patent no. 6,060,646. This patent has also issued in Uruguay 2001, and Australia (as Australian Patent No. 754959 on March 13, 2003) and remains under review in numerous other countries including Canada.
L. Harris, S. Gleddie, J. Simmonds 2004.US Patent No. 09/725,957 which was filed on May 9, 2000 was issued on June 16, 2004. ATolerance of trichothecene mycotoxins in plants through the modification of the ribosomal L3 gene.@.

Research Team:

Post Doctoral Fellow: Dr. Stephen O’Leary Proteome of wheat pollen coats.
Technical Assistant: Ms. Anne Hermans, Msc.
Technical Assistant: Ms. Christine Gagnon, Msc.
Undergraduate Honours Student: Ms. Victoria Chang
Honorary Research Associate: Dr. Constantinos Zarkadas