RESEARCH INTEREST

The plant pathogen, Phytophthora, develops through a series of life stages from dormant propagules to infective zoospore cysts, in the course of infecting a plant root. The transition from one life stage to the next depends on the reception of environmental signals, particularly those generated by host plants. The long?term goal of our research program is to identify and manipulate novel biomolecules that disrupt life stage progression that depends on such signals.

RESEARCH

The plant pathogen, Phytophthora, develops through a series of life stages from dormant propagules to infective zoospore cysts, in the course of infecting a plant root. The transition from one life stage to the next depends on the reception of environmental signals, particularly those generated by host plants. The long?term goal of our research program is to identify and manipulate novel biomolecules that disrupt life stage progression that depends on such signals.

Currently, we are using a combinatorial, phage-display approach to identify and characterize peptides that interfere with development of Phytophthora species. We have suggested that there exist Phytophthora cell?surface receptors whose targeting will inhibit subsequent developmental (i.e., infectious) processes, and that phage display will identify ligands that target these receptors. Our rationale for these studies is that peptides targeting these receptors (defined broadly as any ligand?binding molecule) will provide a molecular genetic, environmentally benign, method of disease control.

In a second project, we are studying partial resistance of soybean to Phytophthora sojae. Partial resistance currently is defined only on the basis of soybean field performance in the presence of the pathogen. Resistance ratings reflect only yield; they do not reflect an understanding of mechanisms by which plants withstand infection to produce a crop. Currently, we are characterizing the expression of pathogenesis?related (PR) proteins in infected soybean plants of varying resistance. PR proteins are being used as resistance markers that will assist in localizing the timing and tissue specificity of plant defense responses in these cultivars.


SELECTED PUBLICATIONS

Fang, D.F., Laskey, J.G., Huang, S., Bilyeu, K.D., Morris, R.O., Schmidt, F.J., and English, J.T.  2006.  Combinatorially selected defense peptides protect plant roots from pathogen infection. PNAS 103:18444-18449.

Gluszka, P., Frebortova, j., Luhova, L., Bilyeu, K., English J.T., and Frebort, I.  2005. Tissue localization of cytokinin dehydrogenase in maize: possible involvement of quinone species generated from plant phenolics by other enzymatic systems in the catalytic reaction. Plant Cell Physiol. 46:716-728.  

English, J.T., and Schmidt, F.J. 2005. Phage-display plant defense peptides directed against Phakopsora pachyrhizi and Uromyces appendiculatus. Filed August, 2005.

J. Frébort,  Fraaije, M., Galuszka, P., Sebela, M.,  Pec, P., Hrbác, J. Novak, O., Bilyeu, K.  English, J., and Frebort, I. 2004.  Catalytic reaction of cytokinin dehydrogenase: Preference for of quinone species as electron acceptors. Biochemical Journal 380:121-130.

Emery, K.M., Beuselinck, P.R., and English, J.T. 2002.  Genetic diversity and virulence of Rhizoctonia species associated with plantings of Lotus corniculatus. Mycol. Res. 107:183-189.

Bishop-Hurley, S.L., Mounter, S.A., Laskey, J., Morris, R.O., Elder, J., Roop, P., Rouse, C., Schmidt, F.J., and English, J.T. 2002. Phage-display peptides as developmental agonists for Phytophthora capsici zoospores. Appl. Env. Microbiol. 68:3315-3320. 

English, J.T., and Beuselinck, P.R. 2000. Methods for evaluating birdsfood trefoil for susceptibility to foliar and shoot blight caused by Rhizoctonia spp. Crop Science 40(3):841-843.