National University of Ireland, Maynooth

National University of Ireland, Maynooth
Skip top page links and go directly to the main navigation
The Callan Building
Skip main navigation and go directly to page content

Faculties & Departments

Department of Biology

Philip J. Dix, BSc, PhD, (Leicester) EurBiol
Head of Laboratory

Plant Cell Biology

Prof. P.J. DixHead of Laboratory

Philip J. Dix, BSc, PhD, (Leicester) EurBiol

Research Interests

This research group has a longstanding interest in environmental stress responses in plants, as well as in vitro mutagenesis, and recombinant protein expression systems in transgenic plants. In recent years a strong emphasis has been on the development of the chloroplast genome (plastome) as a target for genetic transformation, and the resulting chloroplasts as a production platform for recombinant proteins. The attractions of this emergent field of plant biotechnology (particularly high and consistent protein expression levels, and genetic containment) have become increasingly apparent and attracted the attention of funding agencies and industry. The Maynooth group has long been at the vanguard of these developments in Europe, and co-ordinated the activities of major EU consortia under the 4th and 5th Framework programmes.

In addition to studies into the technical development of efficient plastid transformation and expression protocols, the methodology is now being used to explore a number of fundamental and applied questions. These include the roles of reactive oxygen species scavenging enzymes, and calcium signaling, in response to abiotic stresses, metabolic engineering of starch and protein quantity and composition, agronomic traits such as herbicide and insect resistance, and the production of oral vaccines (HIV, TB and diabetes). The team has also been instrumental in extending this demanding technology beyond the traditional model species (tobacco), to include potato, tomato and cauliflower, and has commenced work on an important forage crop, perennial ryegrass. Current EU and SFI funded research is focussed on development of an efficient plastid transformation procedure for oilseed rape, and the use of this technology to produce high yields of human membrane proteins for structural studies (in collaboration with Professor John Findlay).
Another area of investigation is the regulation of peroxidase genes, the targeting of the gene product and its role in plant development and stress tolerance. Tobacco plants over-expressing peroxidases in the cell wall (apoplast) or cytoplasm, sometimes in combination with other oxidative enzymes (oxalate oxidase), have been shown to result in changes in such developmental features as xylem production, and in resistance to abiotic (UV, temperature, high light, ozone) and biotic (insects, pathogens) stresses.

Laboratory Personnel

Post-Doctoral Fellows

  • Dr. Manfred Klaas, DipBiol, PhD (Kiel)
  • Dr. Peter Medgyesy, BSc, PhD (Szeged)
  • Dr. Julia Hinderberger, DipChem, PhD (Marburg)

Postgraduate Students

  • Benedicte Le Martret
  • Rob Van Den Bekerom

Technical Assistant (part time)

  • Aine Butler

Funding Sources

EU, Enterprise Ireland, Science Foundation Ireland, Teagasc, Departmental funding

Selected Publications

 

  • Nguyen, T.T., Dix, P.J. and Nugent, G.D.: Nuclear transformation of potato via Agrobacterium coated microparticle bombardment. Biologia Plantarum 54, 141-144 (2010)
  • Marusic, C.,  Vitale, A., Pedrazzini, E., Donini, M., Frigerio, L. , Bock, R., Dix, P.J., McCabe, M.S., Belucci, M., and Benvenuto E.: Plant-based strategies aimed at expressing HIV antigens and neutralizing antibodies at high levels. Nef as a case study. Transgenic Research 18, 499-512 (2009)
  • Diekmann, K., Hodkinson, T.R., Wolfe, K.H., Van Den Bekerom, R., Dix, P.J. and Barth, S.: Complete chloroplast genome sequence of a major allogamous forage species, perennial ryegrass (Lolium perenne L.). DNA Research 16, 165-176 (2009)
  • Chikkala, V.R.N., Nugent, G.D., Dix, P.J. and Stevenson, T.W.: Regeneration from leaf explants and protoplasts of Brassica oleracea var. botrytis (cauliflower). Scientia Horticulturae 119, 330-334 (2009)
  • McCabe, M.S., Klaas, M, Gonzalez-Rabade, N., Poage, M., Badillo-Corona, J., Zhou, F., Karcher, D., Bock, R., Gray, J.C. and Dix, P.J.: Plastid transformation of high biomass tobacco variety Maryland Mammoth for production of HIV-1 p24 antigen. Plant Biotechnology Journal 6, 914-929 (2008)
  • Craig, W., Lenzi, P., Scotti, N., De Palma, M., Saggese, P., Carbone, V., Mcgrath Curran, N., Magee, A.M., Medgyesy, P., Kavanagh, T.A., Dix, P.J., Grillo, S. and Cardi, T.: Transplastomic tobacco plants expressing a fatty acid desaturase gene exhibit altered fatty acid profiles and improved cold tolerance. Transgenic Research 17, 769-782 (2008)
  • Nguyen, K.-H., Jordi, W., Van Dun, K., Schepers, F., Davelaar, E., Stoopen, G., Dix, P.J. and Kane, E.J.: Delayed senescence in cauliflower transformed with an autoregulated isopentenyl transferase gene. International Journal of Plant Science 169, 339-347 (2008)
  • Burbridge, E., Diamond, M., Dix, P.J. and McCabe, P.F.: Use of cell morphology to evaluate the effect of a peroxidase gene on cell death induction thresholds in tobacco. Plant Science 171, 138-146 (2006)
  • Nugent, G.D., Coyne, S., Nguyen, T.T., Kavanagh T.A. and Dix, P.J.: Nuclear and plastid transformation of Brassica oleracea var. botrytis (cauliflower) using PEG-mediated uptake of DNA into protoplasts. Plant Science 170, 135-142 (2006)
  • Heggie, L., Jansen, M.A.K., Burbridge, E.M., Kavanagh, T.A., Thorneley, R.N.F. and Dix, P.J.: Transgenic tobacco (Nicotiana tabacum L. cv. Samsun-NN) plants over-expressing a synthetic HRP-C gene are altered in growth, development and susceptibility to abiotic stress. Plant Physiology and Biochemistry  43, 1067-1073 (2005)
  • Nguyen, T.T., Nugent, G.D., Cardi, T. and Dix, P.J.: Generation of homoplasmic plastid transformants of a commercial cultivar of potato (Solanum tuberosum L.). Plant Science 168, 1,495-1,500 (2005)
  • Craig, W., Gargano, D., Scotti, N., Nguyen, T.T., Lao, N.T., Kavanagh T.A., Dix P.J. and Cardi. T.: Direct gene transfer in potato: a comparison of particle bombardment of leaf explants and PEG-mediated transformation of protoplasts. Plant Cell Reports 24, 603-611 (2005)
  • Ma, J.K.-C., Barros, E., Bock, R., Christou, P., Dale, P.J., Dix, P.J., Fischer, R., Irwin, J., Mahoney, R., Pezzotti, M., Schillberg, S., Sparrow P. and Twyman, R.M.: The production of pharmaceutical proteins in transgenic plants – current perspectives. EMBO Reports 6, 593-599 (2005)
  • Altpeter, F., Baisakh,N., Beachy, R., Bock, R., Capell, T., Christou, P., Daniell, H., Datta, K., Datta, S., Dix, P.J., Fauquet, C., Huang, N., Kohli, A., Mooibroek, H.,  Nicholson, L.,  Nguyen, T.T., Nugent, G., Raemakers, K.,  Romano, A., Somers, D.A., Stoger, E.,  Taylor N. and Visser. R.: Particle bombardment and the genetic enhancement of crops: myths and realities. Molecular Breeding 15, 305-327 (2005)
  • Nugent, G.D., ten Have, M., van der Gulik, A., Dix, P.J., Uijtewaal, B.A. and Mordhorst, A.P.: Plastid transformants in tomato selected using mutations affecting ribosome structure. Plant Cell Reports 24, 341-349 (2005)
  • Jansen, M.A.K., Elfstrand, M., Heggie, L., Sitbon, F., Dix, P.J. and Thorneley, R.N.F.: Over-expression of phenol-oxidising peroxidases alters the UV-susceptibility of transgenic Nicotiana tabacum. New Phytologist 163, 585-594 (2004)
  • Kis, M., Burbridge, E., Brock, I.W., Heggie, L., Dix, P.J. and Kavangh, T.A.: An N-terminal peptide extension results in efficient expression, but not secretion, of a synthetic horseradish peroxidase gene in transgenic tobacco. Annals of Botany 93, 303-310 (2004)
Last edited: Thursday, 25-Feb-2010 12:45:00 GMT

Biology Department , NUI Maynooth
Tel: +353-1-708 3843 | Fax: +353-1-708 3845| Email: terry.roche@nuim.ie