Metabolism, biochemistry, biotechnology, amino acids, stress, biotic, abiotic, resistance

Research Interests:

My primary research is concerned with developing abiotic and biotic stress resistance in plants using genetic engineering strategies. My principal approach involves GABA (gamma-aminobutyrate), a ubiquitous 4-C, non-protein amino acid of uncertain function in plants. However, it does accumulate in response to a variety of abiotic and biotic stresses, including temperature and oxygen shock, as well as insect damage. Currently, we continuing to identify the proteins involved in GABA metabolism and transport, and their corresponding genes, using state-of-the- art analytical tools and biochemical and molecular techniques. These genes are typically being expressed in recombinant expression systems, with the recombinant proteins being isolated and purified for biochemical and physical characterization. The genes are also being modified and reinserted by Agrobacterium-mediated transformation or particle bombardment. The availability of various mutants (sense, antisense and knockouts) will facilitate studies of the true physiological function of GABA synthesis, co-ordinated plant responses to altered GABA levels using a proteomic approach, and address specific biotechnological applications such as nematode resistance. In addition to manipulating pathways associated with GABA metabolism, we are also collaborating in investigations of N use efficiency and C/N interactions in model plant systems.

Selected Publications:

Allan, A.W. and B.J. Shelp. (2006). Fluctuations of (-aminobutyrate, (-hydroxybutyrate and related amino acids in Arabidopsis leaves as a function of the light-dark cycle, leaf age and N stress. Can. J. Bot. (in press)

Bown, A.W., K.B. MacGregor, B.J. Shelp. (2006). Gamma-aminobutyrate: defence against invertebrate pests? Trends Plant Sci. (in press).

Chevrot, R., R. Rosen, E. Haudecoeur, A. Cirou, B.J. Shelp, E. Ron and D. Faure. GABA controls the level of quorum-sensing signal in Agrobacterium tumefaciens. Proc. Natl. Acad. Sci. 103: 7460-7464.

Shelp, B.J., O.R. Van Cauwenberghe and A.W. Bown. (2003). Gamma-aminobutyrate: from intellectual curiosity to practical pest control. Can. J. Bot. 81:1045-1048.

Breitkreuz, K.E., W.A. Allan, O.R. Van Cauwenberghe, C. Jakobs, D. Talibi, B. André and B.J. Shelp. (2003). A novel gamma-hydroxybutyrate dehydrogenase: identification and expression of an Arabidopsis cDNA and potential role under oxygen deficiency. J. Biol. Chem. 278:41552-41556.

MacGregor, K.E., B.J. Shelp, S.E. Peiris and A.W. Bown. (2003). Overexpression of glutamate decarboxylase in transgenic tobacco deters feeding by phytophagous insect larvae. J. Chem. Ecol. 29:2177-2182.

Allan, W.A., C. Peiris, A.W. Bown and B.J. Shelp. (2003). Gamma hydroxybutyrate accumulates in green tea and soybean sprouts after anaerobic treatment. Can. J. Pl. Sci. 83:951-953.

Yevtushenko, D., M.D. McLean, S.E. Peiris, O.R. Van Cauwenberghe and B.J. Shelp. (2003). Calcium/calmodulin activation of two divergent glutamate decarboxylases from tobacco. J. Exp. Bot. 54: 2001-2002.

McLean, M.D., D.P. Yevtushenko, D. Deschene, O.R. Van Cauwenberghe, A. Makhmoudova, J.W. Potter, A.W. Bown and B.J. Shelp. (2003). Overexpression of glutamate decarboxylase in transgenic tobacco confers resistance to the northern root-knot nematode. Mol. Breed. 11:277-285.

Van Cauwenberghe, O.R., A. Makhmoudova, M.D. McLean, S.M. Clark, B.J. Shelp. (2002). Plant gamma-aminobutyrate transaminase: Identification of an Arabidopsis cDNA and its expression in Escherichia coli. Can. J. Bot. 80:933-941.