Dr. Walt Ream, Professor

Ream Office 1081 ALS
Phone 541-737-1791
FAX 541-737-0496
Email reamw@oregonstate.edu
Education Ph.D., University of California, Berkeley

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

Courses Taught:  MB 311 Molecular Microbiology Lab: A Writing Intensive Course; taught: MB 303, General Microbiology Laboratory



Agrobacterium 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. agrobacterium ream

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 tumor 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.



Pub Med

Klein, J.M., Bennett, R.W., MacFarland, L., Abranches Da Silva, M.E., Meza-Turner, B.M., Dark, P.M., Frey, M.E., Wellappili, D.P., Beugli, A.D., Jue, H.J., Mellander, J.M., Wei, W. and Ream, W.  2015.  Draft genome sequence of Erwinia billingiae OSU 19-1, isolated from a pear tree canker.  Genome Announc.  3(5): pii: e01119-15.

Galambos, A., Zok, A., Kuczmog, A., Oláh, R., Putnoky, P., Ream, W. Szegedi, E.  2013.  Silencing Agrobacterium oncogenes in transgenic grapevine results in strain-specific crown gall resistance. Plant Cell Rep. 32(11):1751-7.

Hodges, L.D., Lee, L.Y., McNett, H., Gelvin, S.B. and W. Ream. Agrobacterium rhizogenes GALLS gene encodes two secreted proteins required for gene transfer to plants. J. Bacteriol. 191: 355-364 (2009).

Ream, W. Agrobacterium tumefaciens and A. rhizogenes use different proteins to transport bacterial DNA into the plant cell nucleus. Microbial Biotechnology, doi:10.1111/ j.1751-7915.2009.00104.x (June, 2009).

Ream, W. Genetically engineered plants: greener than you think. Microbial Biotechnology, doi:10.1111/ j.1751-7915.2009.00088.x (June, 2009).

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).

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. J. Archaeol. Sci. 32: 27-38 (2005).

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).

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).

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

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).

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.S. 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).

Hamilton, C.M., Lee, H., Li, P.L., Cook, D.M., Piper, K.R., Beck von Bodman, S., Lanka, E., Ream, W. and S.K. Farrand. TraG and its homologs from pTiC58 and RP4 confer relaxosome specificity to the Ti plasmid conjugal transfer system. J. Bacteriol. 182: 1541-1548 (2000).

Gu, Q.P., Sun, Y., Ream, W. and P.D. Whanger. Selenoprotein W accumulates primarily in primate skeletal muscle, heart, brain and tongue. Molec. Cellular Biochem. 204: 49-56 (2000).

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).

Sundberg, C.D. and W. Ream. Agrobacterium tumefaciens chaperone-like protein, VirE1, interacts with VirE2 at domains required for single-stranded DNA binding and cooperativity. J. Bacteriol. 181: 6850-6855 (1999).

Gu, Q.P., Beilstein, M.A., Barofsky, E., Ream, W. and P.D. Whanger. Purification, characterization and glutathione binding to selenoprotein W from monkey muscle. Arch. Biochem. Biophys. 361: 25-33 (1999).

Whistler, C.A., Corbell, N., Sarniquet, A., Ream, W. and J.E. Loper. The two-component regulators GacS and GacA influence accumulation of the stationary-phase sigma factor and stress response in Pseudomonas fluorescens Pf-5. J. Bacteriol. 180: 6635-6641 (1998).

Mysore, K.S., Bassuner, B., Deng, X., Darbinian, N.S., Motchoulski, A., Ream, W. and S.B. Gelvin. Role of the Agrobacterium tumefaciens VirD2 protein in T-DNA transfer and integration. Mol. Plant-Microbe Interactions 11: 668-683 (1998).

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).

Haas, J.H., Moore, L.W., Ream, W., and S. Manulis. Universal PCR primers for detection of pathogenic Agrobacterium species. Appl. Environ. Microbiol. 61: 2879-2884 (1995).

Vendeland, S.C., Beilstein, M.A., Yeh, J.-Y., Ream, W., and P.D. Whanger. Rat skeletal muscle selenoprotein W: cDNA clone and mRNA modulation by dietary selenium. Proc. Natl. Acad. Sci. USA 92: 8749-8753 (1995).

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. Kund, eds., World Scientific press, London, p. 107-118 (1994).

Keim-Miller, C.A., Ream, W., and D.W. Mosbaugh. DNA helicase activity detected in situ following polyacrylamide gel electrophoresis. Meth. Molec. Cell. Biol. 3: 259-269 (1993).

Shurvinton, C.E., Hodges, L., and W. Ream. A nuclear localization signal and the C-terminal omega sequence in the Agrobacterium tumefaciens VirD2 endonuclease are important for tumor formation. Proc. Natl. Acad. Sci. USA 89: 11837-11841 (1992).

Miranda, A., Janssen, G., Hodges, L., Peralta, E.G., and W. Ream. Agrobacterium tumefaciens transfers extremely long T-DNAs by a unidirectional mechanism. J. Bacteriol. 174: 2288-2297 (1992).

Shurvinton, C. E. and W. Ream. Stimulation of Agrobacterium tumefaciens T-DNA transfer by overdrive depends on a flanking sequence but not on helical position with respect to the border repeat. J. Bacteriol. 173: 5558-5563 (1991).