Department of Botany and Plant Pathology

Joyce E. Loper Professor (Courtesy), Ph.D., 1983, University of California, Berkeley loperj@science.oregonstate.edu Faculty of Center for Genome Research and Biocomputing   Office/Lab: USDA Horticultural Crops Unit Phone: 541-738-4057

Research Area

Genomics and molecular genetics of prokaryotes, microbial ecology, biological control of plant disease.

Description of Research

My laboratory group studies plant-microbe interactions with an emphasis on plant-associated bacteria.  We are using molecular and ecological approaches to study the nature of microbial habitats on plant surfaces, intracellular signaling, and patterns of gene expression by bacteria living in natural environments. We recently completed the genome sequence of Pseudomonas fluorescens Pf-5, the first biological control agent for plant disease whose genomic sequence is known.   A current focus is on the identification of novel secondary metabolites from the genome of Pf-5, and evaluating these compounds for suppression of plant disease.

Research Group Members

Faculty Research Assistants/Associates

Marcella Henkels
Brenda Shaffer

Graduate Students

Sierra Hartney (PhD expected 2010)

Postdoctoral Fellow

Teresa Sweat

Visiting Scientists

Baruch Sneh, Tel-Aviv University , Israel

Related Links

USDA-ARS Horticultural Crops Research Laboratory

Publications

Loper, J.E., Kobayashi, D.Y., and Paulsen, I.T.  2007. The genomic sequence of Pseudomonas fluorescens Pf-5: Insights into biological control.  Phytopathology 97:233-238.

Gross, H., Stockwell, V.O., Henkels, M.D., Nowak-Thompson, B., Loper, J.E., and Gerwick, W.H.  2007.  The Genomisotopic Approach: A Systematic Method to Isolate Products of Orphan Biosynthetic Gene Clusters.  Chemistry and Biology 14: 53-64.

Paulsen, I. T., Press, C. M., Ravel, J., Kobayashi, D. Y., Myers, G. S. A., Mavrodi, D. V., DeBoy, R. T., Seshadri, R., Ren, Q., Madupu, R., Dodson, R. J., Durkin, A. S., Brinkac, L. M., Daugherty, S. C., Sullivan, S. A., Rosovitz, M. J., Gwinn, M. L., Zhou, L., Schneider, D. J., Cartinhour, S. W., Nelson, W. C., Weidman, J., Watkins, K., Tran, K., Khouri, H., Pierson, E. A., Pierson, L. S., III, Thomashow, L. S. and Loper, J. E. 2005. Complete genome sequence of the plant commensal Pseudomonas fluorescens Pf-5. Nature Biotechnology 23: 873-878.  

Stockwell, V. O., and Loper, J. E. 2005. The sigma factor RpoS is required for stress tolerance and environmental fitness of Pseudomonas fluorescens Pf-5. Microbiology 151: 3001-3009.

Brodhagen, M., Paulsen, I. T., and Loper, J. E. 2005. Reciprocal regulation of pyoluteorin production with membrane transporter gene expression in Pseudomonas fluorescens Pf-5. Appl. Environ. Microbiol. 71:6900-6909.

Feil, H., Feil, W. S., Chain, P., Larimer, F., DiBartolo, G., Copeland, A., Lykidis, A., Trong, S., Nolan, M., Goltsman, E., Thiel, J., Malfatti, S., Loper, J. E., Lapidus, A., Detter, J. C., Land, M., Richardson, P. M., Kyrpides, N.C., Ivanova, N., and Lindow, S. E. 2005. Comparison of the complete genome sequences of Pseudomonas syringae pv. syringae B728a and pv. tomato DC3000. Proc. Natl. Acad. Sci. ( USA ) 102: 11064–11069.

Brodhagen, M., Henkels, M. D., and Loper, J. E. 2004. Positive autoregulation of the antibiotic pyoluteorin in the biological control organism Pseudomonas fluorescens Pf-5. Appl. Environ. Microbiol. 70: 1758-1766.

Anderson , L.M., Stockwell, V.O., and Loper, J.E. 2004. An extracellular protease of Pseudomonas fluorescens Pf-5 inactivates antibiotics of Pantoea agglomerans . Phytopathology 94:1228-1234.