Walt Ream

Plant-Microbe Interactions, Genetic Recombination, Protein Interactions, and Ancient DNA

Ream Photo

Research Interests: Plant-microbe interactions; Agrobacterium tumefaciens; DNA-protein interactions

Office: 1081 Agricultural & Life Sciences

Telephone: 541.737.1791

FAX: 541.737.0496

email: reamw@oregonstate.edu

Courses taught: MB 311 Molecular Microbiology Lab: A Writing Intensive Course; MB 554 Microbial Genetics

Degrees: Ph.d. University of California, Berkeley

RESEARCH

Agrobacterium tumefaciens is the only prokaryote known to transfer genes to a eukaryote. A. tumefaciens is important both as a pathogen and as a means to introduce novel genes into plants. Our laboratory studies secreted virulence proteins that mediate transfer of tumor-inducing genes from Agrobacterium into plant cells.

A. tumefaciens translocates several virulence proteins and oncogenic DNA into plant cells through a type IV secretion system. Similar secretion systems are required for the virulence of many bacterial species that infect humans. However, the Agrobacterium secretion system is the best characterized because A. tumefaciens is easier to study than most animal pathogens. A. tumefaciens transfers specific genes into plant cells where these genes integrate into plant nuclear DNA. Plant tumor cells express transferred genes responsible for tumorous growth and for production of novel compounds that the tumor-inducing bacteria use as nutrients. Thus, A. tumefaciens engineers plant cells to grow rapidly and produce nutrients for the bacteria.

Our work will continue to focus on transfer and integration of A. tumefaciens DNA in plants.

SELECTED PUBLICATIONS

Pub Med

Ream, W. VirD2 and production of a mobile T-DNA. In: Agrobacterium: From Biology to Biotechnology, Chapter 8, pages 279-313; T. Tzfira & V. Citovsky, eds., Springer (2008).

Leonard, J.A., Shanks, O.C., Hodges, L., Ream, W., Hofreiter, M., Wayne, R.K. and R.C. Fleischer. DNA everywhere: Ancient DNA studies identify extraneous DNA in PCR reagents. J. Archaeological Sci. 34: 1361-1366 (2007).

Hodges, L.D., Vergunst, A.C., Neal-McKinney, J., den Dulk-Ras, A., Moyer, D.M., Hooykaas, P.J.J. and W. Ream. Agrobacterium rhizogenes GALLS protein contains domains for ATP-binding, nuclear localization, and type IV secretion. J. Bacteriol. 188: 8222-8230 (2006).

Humann, J., Andrews, S., and W. Ream. VirE1-Mediated Resistance to Crown Gall in Transgenic Arabidopsis thaliana. Phytopathology 96: 105-110 (2006).

Hooven, L.A., Butler, J., Ream, L.W. and P.D. Whanger. Microarray analysis of selenium-depleted and selenium-supplemented mice. Biological Trace Element Res. 109: 173-179 (2006).

Hooven, L.A., Vorachek, W.R., Bauman, A.B., Butler, J.A., Ream, L.W. and P.D. Whanger. Deletion analysis of rodent selenoprotein W promoter. J. Inorg. Biochem. 99: 2007-2012 (2005).

Shanks, O.C., Hodges, L., Tilley, L., Kornfeld, M., Larson, M.L., and W. Ream. DNA from ancient stone tools and bones excavated at Bugas-Holding, Wyoming.

Hodges, L.D., Cuperus, J. and W. Ream. Agrobacterium rhizogenes GALLS protein substitutes for A. tumefaciens single-stranded DNA-binding protein VirE2. J. Bacteriol. 186: 3065-3077 (2004).

Amantana, A., Vorachek, W.R., Butler, J.A., Ream, W. and P.D. Whanger. Identification of putative transcription factor binding sites in rodent selenoprotein W promoter. J. Inorganic Biochem. 98: 1513-1520 (2004).

Shanks, O.C., Kornfeld, M., Hodges, L. and W. Ream. DNA and protein recovery from washed stone tools: a blind test. Archaeometry 46: 663-672 (2004).

Bauman, A.B., Vorachek, W.R., Butler, J.A., Ream, W. and P.D. Whanger. Deletion analysis of rodent selenoprotein W promoter. J. Inorg. Biochem., in press (2005).

Hooven, L.A., Butler, J., Ream, L.W. and P.D. Whanger. Microarray analysis of selenium-depleted and selenium-supplemented mice. Biological Trace Element Res. 108: 1-7 (2005).

Ream, W. Silencing crown gall disease. American Nurseryman 199: 8 (2004).

Viss, W., Pitrak, J., Humann, J.L., Cook, M., Driver, J. and W. Ream. Crown-gall-resistant transgenic apple trees that silence Agrobacterium tumefaciens oncogenes. Molecular Breeding 12: 283-295 (2003).

Lee, H., Humann, J., Pitrak, J., Cuperus, J., Parks, T.D., Whistler, C., Mok. M. and W. Ream. Translational Start Sequences Affect the Efficiency of Silencing of Agrobacterium tumefaciens T-DNA Oncogenes. Plant Physiol. 133: 966-977 (2003).

Ream, W., B. Geller, J. Trempy and K. Field. Molecular Microbiology Laboratory: A Writing Intensive Course. Academic Press (2003).

Ream, W. Agrobacterium genetics. In: Modern Microbial Genetics, second edition, U. N. Streips and R. E. Yasbin, eds. Wiley & Sons (2002).

Gu, Q.P., Ream, W. and P.D. Whanger. Selenoprotein W gene regulation by selenium in L8 cells. BioMetals 15: 411-420 (2002).

Shanks, O., Vella, A.T., Bonnichsen, R. and W. Ream. Recovery of protein and DNA trapped in stone tool microcracks. J. Archaeological Science 28: 965-972 (2001).

Bissonette, L., O. Shanks and W. Ream. Sequence powertools: Lasergene 5.0 by DNA Star. Science 293: 129 (2001).

Ream, W., Vorachek, W., and P.D. Whanger. Selenoprotein W: A muscle protein in search of a function. Chapter 12, pp. 137-146. In: Selenium: Its molecular biology and role in human health, D.L. Hatfield, ed., Klewer (2001).

Shanks, O., Bissonette, L., and W. Ream. Pretty Plamids: A new plasmid drawing program for PC users - Textco Gene Construction Kit 2. Science 289: 413 (2000).

Ream, W. Import of Agrobacterium tumefaciens virulence proteins and transferred DNA into plant cell nuclei. In: Subcellular Biochemistry, Vol. 29, B.B. Biswas & H.K. Das, eds. Pages 365-384. Plenum, (1998).

Ream, W. and K.G. Field. Molecular Biology Techniques: An Intensive Laboratory Course. Academic Press (1998).

Sundberg,C., Meek, L., Carroll,K., Dombek, P., Das, A., and W. Ream. VirE1 protein mediates export of the single-stranded DNA-binding protein VirE2 from Agrobacterium tumefaciens into plant cells. In: Crown Gall, W. Ream and S.B. Gelvin, eds., American Phytopathol. Society, St. Paul, MN, pp. 126-145 (1996).

Narasimhulu, S.B., Nam, J., Deng, X., Sarria, R., Ream, W., and S.B. Gelvin. Agrobacterium and plant genes affecting T-DNA transfer and integration. In: Crown Gall, W. Ream and S.B. Gelvin, eds., American Phytopathological Society, St. Paul, Minnesota, pp. 99-125 (1996).

Hodges, L. Shurvinton, C.E., and W. Ream. A nuclear localization signal in the Agrobacterium tumefaciens VirD2 border endonuclease is essential for crown gall tumorigenesis. In: Biotechnology and Plant Protection, D.D. Bills and S.D. Kung, eds., World Scientific Press, London, p. 107-118 (1994).