Skip to main content Accessibility help
Hostname: page-component-55597f9d44-ms7nj Total loading time: 0.346 Render date: 2022-08-13T23:08:18.254Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "useRatesEcommerce": false, "useNewApi": true } hasContentIssue true

3 - Quorum-sensing-mediated regulation of plant–bacteria interactions and Agrobacterium tumefaciens virulence

Published online by Cambridge University Press:  08 August 2009

Catharine E. White
Department of Microbiology, Cornell University Ithaca, NY USA
Stephen C. Winans
Department of Microbiology, Cornell University Ithaca, NY USA
Donald R. Demuth
University of Louisville, Kentucky
Richard Lamont
University of Florida
Get access



Plant-associated bacteria have a wide range of interactions with their hosts, from non-specific associations to more dedicated symbiotic or pathogenic interactions. Many complex interactions take place between plant roots and associated bacteria, fungi, and protozoa in a highly diverse and dense community within the rhizosphere. Bacterial cell-to-cell communication systems in this ecological niche appear to affect biofilm formation, pathogenesis, and production of siderophores and antibiotics. These activities are no doubt important in root colonization as well as in symbiosis and pathogenesis. Exciting developments and current studies in understanding the many complex interactions in the rhizosphere include both the characterization of the microbial communities involved and the responses of the plant hosts to these communities. Cell-to-cell signaling between members of the community is no doubt critical for these interactions to sense population densities and diffusion barriers in the rhizosphere. Such studies are beyond the scope of this chapter, but we refer the reader to recent reviews of this field (43, 65, 82).

Perhaps the best-characterized group of soil bacteria that serves as the model for understanding plant–bacteria associations is the Rhizobiaceae. This family, in the alpha subgroup of the Proteobacteria, includes members of the genera Rhizobium, Sinorhizobium, Mesorhizobium, Azorhizobium, and Bradyrhizobium (collectively referred to here as rhizobia), which form symbiotic relationships with host plants, and several pathogenic species of the genus Agrobacterium (including A. tumefaciens, A. rhizogenes, A. vitis, and A. rubi, here referred to as agrobacteria).

Bacterial Cell-to-Cell Communication
Role in Virulence and Pathogenesis
, pp. 39 - 64
Publisher: Cambridge University Press
Print publication year: 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)


Alt-Morbe, J., Stryker, J. L., Fuqua, al. 1996. The conjugal transfer system of Agrobacterium tumefaciens octopine-type Ti plasmids is closely related to the transfer system of an IncP plasmid and distantly related to Ti plasmid vir genes. J. Bacteriol. 178: 4248–57.CrossRefGoogle ScholarPubMed
Beck von Bodman, S., Hayman, G. T. and Farrand, S. K. 1992. Opine catabolism and conjugal transfer of the nopaline Ti plasmid pTiC58 are coordinately regulated by a single repressor. Proc. Natn. Acad. Sci. USA 89: 643–7.CrossRefGoogle ScholarPubMed
Beck von Bodman, S., McCutchan, J. E. and Farrand, S. K. 1989. Characterization of conjugal transfer functions of Agrobacterium tumefaciens Ti plasmid pTiC58. J. Bacteriol. 171: 5281–9.CrossRefGoogle Scholar
Benoff, B., Yang, H., Lawson, C. al. 2002. Structural basis of transcription activation: the CAP-alpha CTD-DNA complex. Science 297: 1562–6.CrossRefGoogle ScholarPubMed
Busby, S. and Ebright, R. H. 1999. Transcription activation by catabolite activator protein (CAP). J. Molec. Biol. 293: 199–213.CrossRefGoogle Scholar
Chai, Y. and Winans, S. C. 2004. Site-directed mutagenesis of a LuxR-type quorum-sensing transcription factor: alteration of autoinducer specificity. Molec. Microbiol. 51: 765–76.CrossRefGoogle ScholarPubMed
Chai, Y., Zhu, J. and Winans, S. C. 2001. TrlR, a defective TraR-like protein of Agrobacterium tumefaciens, blocks TraR function in vitro by forming inactive TrlR:TraR dimers. Molec. Microbiol. 40: 414–21.CrossRefGoogle ScholarPubMed
Chen, G., Malenkos, J. W., Cha, M. R., Fuqua, C. and Chen, L. 2004. Quorum-sensing antiactivator TraM forms a dimer that dissociates to inhibit TraR. Molec. Microbiol. 52: 1641–51.CrossRefGoogle ScholarPubMed
Cho, K., Fuqua, C., Martin, B. S. and Winans, S. C. 1996. Identification of Agrobacterium tumefaciens genes that direct the complete catabolism of octopine. J. Bacteriol. 178: 1872–80.CrossRefGoogle ScholarPubMed
Cho, K., Fuqua, C. and Winans, S. C. 1997. Transcriptional regulation and locations of Agrobacterium tumefaciens genes required for complete catabolism of octopine. J. Bacteriol. 179: 1–8.CrossRefGoogle ScholarPubMed
Cho, K. and Winans, S. C. 1993. Altered-function mutations in the Agrobacterium tumefaciens OccR protein and in an OccR-regulated promoter. J. Bacteriol. 175: 7715–19.CrossRefGoogle Scholar
Cho, K. and Winans, S. C. 1996. The putA gene of Agrobacterium tumefaciens is transcriptionally activated in response to proline by an Lrp-like protein and is not autoregulated. Molec. Microbiol. 22: 1025–33.CrossRefGoogle Scholar
Choi, S. H. and Greenberg, E. P. 1991. The C-terminal region of the Vibrio fischeri LuxR protein contains an inducer-independent lux gene activating domain. Proc. Natn. Acad. Sci. USA 88: 11115–19.CrossRefGoogle ScholarPubMed
Choi, S. H. and Greenberg, E. P. 1992. Genetic evidence for multimerization of LuxR, the transcriptional activator of Vibrio fischeri luminescence. Molec. Mar. Biol. Biotechnol. 1: 408–13.Google Scholar
Clare, B. G., Kerr, A. and Jones, D. A. 1990. Characteristics of the nopaline catabolic plasmid in Agrobacterium strains K84 and K1026 used for biological control of crown gall disease. Plasmid 23: 126–37.CrossRefGoogle ScholarPubMed
Dessaux, Y., A. Petit, S. K. Farrand and P. J. Murphy 1998. Opines and opine-like molecules involved in plant/Rhizobiaceae interactions. In Spaink, H. P., Kondorosi, A. and Hooykaas, P. J. (eds), The Rhizobiaceae, pp. 173–97. Dordrecht, The Netherlands: Kluwer Academic Publishers.CrossRefGoogle Scholar
Dessaux, Y., A. Petit and J. Tempe 1992. Opines in Agrobacterium biology. In Verma, D. P. S. (ed.), Molecular Signals in Plant-Microbe Communications, pp. 109–36. Ann Arbor, MI: CRC Press.Google Scholar
Dong, Y. H., Gusti, A. R., Zhang, Q., Xu, J. L. and Zhang, L. H. 2002. Identification of quorum-quenching N-acyl homoserine lactonases from Bacillus species. Appl. Environ. Microbiol. 68: 1754–9.CrossRefGoogle ScholarPubMed
Dong, Y. H., Wang, L. H., Xu, J. al. 2001. Quenching quorum-sensing-dependent bacterial infection by an N-acyl homoserine lactonase. Nature 411: 813–17.CrossRefGoogle ScholarPubMed
Dyson, H. J. and Wright, P. E. 2002. Coupling of folding and binding for unstructured proteins. Curr. Opin. Struct. Biol. 12: 54–60.CrossRefGoogle ScholarPubMed
Eberhard, A., Burlingame, A. L., Eberhard, al. 1981. Structural identification of autoinducer of Photobacterium fischeri luciferase. Biochemistry 20: 2444–9.CrossRefGoogle ScholarPubMed
Egland, K. A. and Greenberg, E. P. 2001. Quorum sensing in Vibrio fischeri: analysis of the LuxR DNA binding region by alanine-scanning mutagenesis. J. Bacteriol. 183: 382–6.CrossRefGoogle ScholarPubMed
Ellis, J. G., Kerr, A., Petit, A. and Tempe, J. 1982. Conjugal transfer of nopaline and agropine Ti-plasmids: the role of agrocinopines. Molec. Gen. Genet. 186: 269–73.CrossRefGoogle Scholar
Farrand, S. K. 1998. Conjugal plasmids and their transfer. In Spaink, H. P., Kondorosi, A. and Hooykaas, P. J. J. (eds), The Rhizobiaceae: Molecular Biology of Model Plant-associated Bacteria, pp. 199–233. Dordrecht, The Netherlands: Kluwer Academic Publishers.CrossRefGoogle Scholar
Finney, A. H., Blick, R. J., Murakami, K., Ishihama, A. and Stevens, A. M. 2002. Role of the C-terminal domain of the alpha subunit of RNA polymerase in LuxR-dependent transcriptional activation of the lux operon during quorum sensing. J. Bacteriol. 184: 4520–8.CrossRefGoogle ScholarPubMed
Fuqua, C., Burbea, M. and Winans, S. C. 1995. Activity of the Agrobacterium Ti plasmid conjugal transfer regulator TraR is inhibited by the product of the traM gene. J. Bacteriol. 177: 1367–73.CrossRefGoogle ScholarPubMed
Fuqua, C. and Winans, S. C. 1996. Conserved cis-acting promoter elements are required for density-dependent transcription of Agrobacterium tumefaciens conjugal transfer genes. J. Bacteriol. 178: 435–40.CrossRefGoogle ScholarPubMed
Fuqua, C. and Winans, S. C. 1996. Localization of OccR-activated and TraR-activated promoters that express two ABC-type permeases and the traR gene of Ti plasmid pTiR10. Molec. Microbiol. 20: 1199–210.CrossRefGoogle ScholarPubMed
Fuqua, W. C. and Winans, S. C. 1994. A LuxR-LuxI type regulatory system activates Agrobacterium Ti plasmid conjugal transfer in the presence of a plant tumor metabolite. J. Bacteriol. 176: 2796–806.CrossRefGoogle ScholarPubMed
Gage, D. J. 2004. Infection and invasion of roots by symbiotic, nitrogen-fixing rhizobia during nodulation of temperate legumes. Microbiol. Molec. Biol. Rev. 68: 280–300.CrossRefGoogle ScholarPubMed
Genetello, C., Larebeke, N., Holsters, al. 1977. Ti plasmids of Agrobacterium as conjugative plasmids. Nature 265: 561–3.CrossRefGoogle ScholarPubMed
Goodner, B., Hinkle, G., Gattung, al. 2001. Genome sequence of the plant pathogen and biotechnology agent Agrobacterium tumefaciens C58. Science 294: 2323–8.CrossRefGoogle ScholarPubMed
Gould, T. A., Schweizer, H. P. and Churchill, M. E. 2004. Structure of the Pseudomonas aeruginosa acyl-homoserinelactone synthase LasI. Molec. Microbiol. 53: 1135–46.CrossRefGoogle ScholarPubMed
Hayman, G. T. and Farrand, S. K. 1990. Agrobacterium plasmids encode structurally and functionally different loci for catabolism of agrocinopine-type opines. Molec. Gen. Genet. 223: 465–73.CrossRefGoogle ScholarPubMed
Hayman, G. T. and Farrand, S. K. 1988. Characterization and mapping of the agrocinopine-agrocin 84 locus on the nopaline Ti plasmid pTiC58. J. Bacteriol. 170: 1759–67.CrossRefGoogle ScholarPubMed
He, X., Chang, W., Pierce, D. L., Seib, L. O., Wagner, J. and Fuqua, C. 2003. Quorum sensing in Rhizobium sp. strain NGR234 regulates conjugal transfer (tra) gene expression and influences growth rate. J. Bacteriol. 185: 809–22.CrossRefGoogle ScholarPubMed
Huang, J. J., Han, J. I., Zhang, L. H. and Leadbetter, J. R. 2003. Utilization of acyl-homoserine lactone quorum signals for growth by a soil pseudomonad and Pseudomonas aeruginosa PAO1. Appl. Environ. Microbiol. 69: 5941–9.CrossRefGoogle ScholarPubMed
Hwang, I., Cook, D. M. and Farrand, S. K. 1995. A new regulatory element modulates homoserine lactone-mediated autoinduction of Ti plasmid conjugal transfer. J. Bacteriol. 177: 449–58.CrossRefGoogle ScholarPubMed
Hwang, I., Li, P. L., Zhang, al. 1994. TraI, a LuxI homologue, is responsible for production of conjugation factor, the Ti plasmid N-acylhomoserine lactone autoinducer. Proc. Natn. Acad. Sci. USA 91: 4639–43.CrossRefGoogle ScholarPubMed
Hwang, I., Smyth, A. J., Luo, Z. Q. and Farrand, S. K. 1999. Modulating quorum sensing by antiactivation: TraM interacts with TraR to inhibit activation of Ti plasmid conjugal transfer genes. Molec. Microbiol. 34: 282–94.CrossRefGoogle ScholarPubMed
Johnson, D. C., Ishihama, A. and Stevens, A. M. 2003. Involvement of region 4 of the sigma 70 subunit of RNA polymerase in transcriptional activation of the lux operon during quorum sensing. FEMS Microbiol. Lett. 228: 193–201.CrossRefGoogle ScholarPubMed
Kado, C. I. 1994. Promiscuous DNA transfer system of Agrobacterium tumefaciens: role of the virB operon in sex pilus assembly and synthesis. Molec. Microbiol. 12: 17–22.CrossRefGoogle ScholarPubMed
Kent, A. D. and Triplett, E. W. 2002. Microbial communities and their interactions in soil and rhizosphere ecosystems. A. Rev. Microbiol. 56: 211–36.CrossRefGoogle ScholarPubMed
Kerr, A. 1971. Acquisition of virulence by non-pathogenic isolates of Agrobacterium radiobacter. Physiol. Plant Pathol. 1: 241–6.CrossRefGoogle Scholar
Kerr, A. 1969. Transfer of virulence between isolates of Agrobacterium. Nature 223: 1175–6.CrossRefGoogle Scholar
Kerr, A., Manigault, P. and Tempe, J. 1977. Transfer of virulence in vivo and in vitro in Agrobacterium. Nature 265: 560–1.CrossRefGoogle ScholarPubMed
Leadbetter, J. R. and Greenberg, E. P. 2000. Metabolism of acyl-homoserine lactone quorum-sensing signals by Variovorax paradoxus. J. Bacteriol. 182: 6921–6.CrossRefGoogle ScholarPubMed
Lessl, M., Balzer, D., Pansegrau, W. and Lanka, E. 1992. Sequence similarities between the RP4 Tra2 and the Ti VirB region strongly support the conjugation model for T-DNA transfer. J. Biol. Chem. 267: 20471–80.Google ScholarPubMed
Lessl, M. and Lanka, E. 1994. Common mechanisms in bacterial conjugation and Ti-mediated T-DNA transfer to plant cells. Cell 77: 321–4.CrossRefGoogle ScholarPubMed
Luo, Z. Q. and Farrand, S. K. 1999. Signal-dependent DNA binding and functional domains of the quorum-sensing activator TraR as identified by repressor activity. Proc. Natn. Acad. Sci. USA 96: 9009–14.CrossRefGoogle ScholarPubMed
Luo, Z. Q., Qin, Y. and Farrand, S. K. 2000. The antiactivator TraM interferes with the autoinducer-dependent binding of TraR to DNA by interacting with the C-terminal region of the quorum-sensing activator. J. Biol. Chem. 275: 7713–22.CrossRefGoogle ScholarPubMed
Luo, Z. Q., Smyth, A. J., Gao, P., Qin, Y. and Farrand, S. K. 2003. Mutational analysis of TraR. Correlating function with molecular structure of a quorum-sensing transcriptional activator. J. Biol. Chem. 278: 13173–82.CrossRefGoogle ScholarPubMed
Maris, A. E., Sawaya, M. R., Kaczor-Grzeskowiak, al. 2002. Dimerization allows DNA target site recognition by the NarL response regulator. Nat. Struct. Biol. 9: 771–8.CrossRefGoogle ScholarPubMed
Medina, G., Juarez, K., Valderrama, B. and Soberon-Chavez, G. 2003. Mechanism of Pseudomonas aeruginosa RhlR transcriptional regulation of the rhlAB promoter. J. Bacteriol. 185: 5976–83.CrossRefGoogle ScholarPubMed
Moré, M. I., Finger, L. D., Stryker, J. al. 1996. Enzymatic synthesis of a quorum-sensing autoinducer through use of defined substrates. Science 272: 1655–8.CrossRefGoogle ScholarPubMed
Morris, R. O. 1990. Genes specifying auxin and cytokinin biosynthesis in prokaryotes. In Davies, P. J. (ed.), Plant Hormones and Their Role in Plant Growth and Development, pp. 636–55. Dordrecht, The Netherlands: Kluwer Academic Publishers.Google Scholar
Nester, E. W., Merlo, D. J., Drummond, M. al. 1977. The incorporation and expression of Agrobacterium plasmid genes in crown gall tumors. Basic Life Sci. 9: 181–96.Google ScholarPubMed
Oger, P. and Farrand, S. K. 2001. Co-evolution of the agrocinopine opines and the agrocinopine-mediated control of TraR, the quorum-sensing activator of the Ti plasmid conjugation system. Molec. Microbiol. 41: 1173–85.CrossRefGoogle ScholarPubMed
Oger, P. and Farrand, S. K. 2002. Two opines control conjugal transfer of an Agrobacterium plasmid by regulating expression of separate copies of the quorum-sensing activator gene traR. J. Bacteriol. 184: 1121–31.CrossRefGoogle ScholarPubMed
Oger, P., Kim, K. S., Sackett, R. L., Piper, K. R. and Farrand, S. K. 1998. Octopine-type Ti plasmids code for a mannopine-inducible dominant-negative allele of traR, the quorum-sensing activator that regulates Ti plasmid conjugal transfer. Molec. Microbiol. 27: 277–88.CrossRefGoogle ScholarPubMed
Pappas, K. M. and Winans, S. C. 2003. A LuxR-type regulator from Agrobacterium tumefaciens elevates Ti plasmid copy number by activating transcription of plasmid replication genes. Molec. Microbiol. 48: 1059–73.CrossRefGoogle ScholarPubMed
Pappas, K. M. and Winans, S. C. 2003. The RepA and RepB autorepressors and TraR play opposing roles in the regulation of a Ti plasmid repABC operon. Molec. Microbiol. 49: 441–55.CrossRefGoogle ScholarPubMed
Parkinson, G., Wilson, C., Gunasekera, al. 1996. Structure of the CAP-DNA complex at 2.5 angstroms resolution: a complete picture of the protein-DNA interface. J. Molec. Biol. 260: 395–408.CrossRefGoogle ScholarPubMed
Parsek, M. R., Val, D. L., Hanzelka, B. L., Cronan, J. E. Jr. and Greenberg, E. P. 1999. Acyl homoserine-lactone quorum-sensing signal generation. Proc. Natn. Acad. Sci. USA 96: 4360–5.CrossRefGoogle ScholarPubMed
Pierson, L. S. I., D. W. Wood and S. B. von Bodman 1999. Quorum sensing in plant-associated bacteria. In Dunny, G. M. and Winans, S. C. (eds), Cell-Cell Signaling in Bacteria, pp. 101–15. Washington, DC: ASM Press.Google Scholar
Piper, K. R., Beck von Bodman, S. and Farrand, S. K. 1993. Conjugation factor of Agrobacterium tumefaciens regulates Ti plasmid transfer by autoinduction. Nature 362: 448–50.CrossRefGoogle ScholarPubMed
Piper, K. R., Beck Von Bodman, S., Hwang, I. and Farrand, S. K. 1999. Hierarchical gene regulatory systems arising from fortuitous gene associations: controlling quorum sensing by the opine regulon in Agrobacterium. Molec. Microbiol. 32: 1077–89.CrossRefGoogle ScholarPubMed
Pohlman, R. F., Genetti, H. D. and Winans, S. C. 1994. Common ancestry between IncN conjugal transfer genes and macromolecular export systems of plant and animal pathogens. Molec. Microbiol. 14: 655–68.CrossRefGoogle ScholarPubMed
Qin, Y., Luo, Z. Q. and Farrand, S. K. 2004. Domains formed within the N-terminal region of the quorum-sensing activator TraR are required for transcriptional activation and direct interaction with RpoA from agrobacterium. J. Biol. Chem. 279: 40844–51.CrossRefGoogle ScholarPubMed
Qin, Y., Luo, Z. Q., Smyth, A. al. 2000. Quorum-sensing signal binding results in dimerization of TraR and its release from membranes into the cytoplasm. EMBO J. 19: 5212–21.CrossRefGoogle ScholarPubMed
Sheng, J. and Citovsky, V. 1996. Agrobacterium-plant cell DNA transport: have virulence proteins, will travel. Plant Cell 8: 1699–710.CrossRefGoogle ScholarPubMed
Shoemaker, B. A., Portman, J. J. and Wolynes, P. G. 2000. Speeding molecular recognition by using the folding funnel: the fly-casting mechanism. Proc. Natn. Acad. Sci. USA 97: 8868–73.CrossRefGoogle ScholarPubMed
Stevens, A. M., Fujita, N., Ishihama, A. and Greenberg, E. P. 1999. Involvement of the RNA polymerase alpha-subunit C-terminal domain in LuxR-dependent activation of the Vibrio fischeri luminescence genes. J. Bacteriol. 181: 4704–7.Google ScholarPubMed
Stevens, A. M. and Greenberg, E. P. 1997. Quorum sensing in Vibrio fischeri: essential elements for activation of the luminescence genes. J. Bacteriol. 179: 557–62.CrossRefGoogle ScholarPubMed
Swiderska, A., Berndtson, A. K., Cha, M. al. 2001. Inhibition of the Agrobacterium tumefaciens TraR quorum-sensing regulator. Interactions with the TraM anti-activator. J. Biol. Chem. 276: 49449–58.CrossRefGoogle ScholarPubMed
Trott, A. E. and Stevens, A. M. 2001. Amino acid residues in LuxR critical for its mechanism of transcriptional activation during quorum sensing in Vibrio fischeri. J. Bacteriol. 183: 387–92.CrossRefGoogle ScholarPubMed
Urbanowski, M. L., Lostroh, C. P. and Greenberg, E. P. 2004. Reversible acyl-homoserine lactone binding to purified Vibrio fischeri LuxR protein. J. Bacteriol. 186: 631–7.CrossRefGoogle ScholarPubMed
Val, D. L. and Cronan, J. E. Jr 1998. In vivo evidence that S-adenosylmethionine and fatty acid synthesis intermediates are the substrates for the LuxI family of autoinducer synthases. J. Bacteriol. 180: 2644–51.Google ScholarPubMed
Larebeke, N., Engler, G., Holsters, al. 1974. Large plasmid in Agrobacterium tumefaciens essential for crown gall-inducing ability. Nature 252: 169–70.CrossRefGoogle ScholarPubMed
Vannini, A., Volpari, C. and Marco, S. Di 2004. Crystal structure of the quorum-sensing protein TraM and its interaction with the transcriptional regulator TraR. J. Biol. Chem. 279: 24291–6.CrossRefGoogle ScholarPubMed
Vannini, A., Volpari, C., Gargioli, al. 2002. The crystal structure of the quorum sensing protein TraR bound to its autoinducer and target DNA. EMBO J. 21: 4393–401.CrossRefGoogle ScholarPubMed
Walker, T. S., Bais, H. P., Grotewold, E. and Vivanco, J. M. 2003. Root exudation and rhizosphere biology. Plant Physiol. 132: 44–51.CrossRefGoogle ScholarPubMed
Watson, W. T., Minogue, T. D., Val, D. L., Bodman, S. Beck and Churchill, M. E. 2002. Structural basis and specificity of acyl-homoserine lactone signal production in bacterial quorum sensing. Molec. Cell 9: 685–94.CrossRefGoogle ScholarPubMed
Whitehead, N. A., Barnard, A. M., Slater, H., Simpson, N. J. and Salmond, G. P. 2001. Quorum-sensing in Gram-negative bacteria. FEMS Microbiol. Rev. 25: 365–404.CrossRefGoogle ScholarPubMed
Winans, S. C. 1992. Two-way chemical signaling in Agrobacterium-plant interactions. Microbiol. Rev. 56: 12–31.Google ScholarPubMed
Winans, S. C., J. Zhu and M. I. Moré 1999. Cell density-dependent gene expression by Agrobacterium tumefaciens during colonization of crown gall tumors. In Dunny, G. M. and Winans, S. C. (eds), Cell-Cell Signaling in Bacteria, pp. 117–28. Washington, DC: ASM Press.Google Scholar
Wood, D. W., Setubal, J. C., Kaul, al. 2001. The genome of the natural genetic engineer Agrobacterium tumefaciens C58. Science 294: 2317–23.CrossRefGoogle ScholarPubMed
Zhang, H. B., Wang, C. and Zhang, L. H. 2004. The quormone degradation system of Agrobacterium tumefaciens is regulated by starvation signal and stress alarmone (p)ppGpp. Molec. Microbiol. 52: 1389–401.CrossRefGoogle ScholarPubMed
Zhang, H. B., Wang, L. H. and Zhang, L. H. 2002. Genetic control of quorum-sensing signal turnover in Agrobacterium tumefaciens. Proc. Natn. Acad. Sci. USA 99: 4638–43.CrossRefGoogle ScholarPubMed
Zhang, L., Murphy, P. J., Kerr, A. and Tate, M. E. 1993. Agrobacterium conjugation and gene regulation by N-acyl-L-homoserine lactones. Nature 362: 446–8.CrossRefGoogle ScholarPubMed
Zhang, L. H. and Kerr, A. 1991. A diffusible compound can enhance conjugal transfer of the Ti plasmid in Agrobacterium tumefaciens. J. Bacteriol. 173: 1867–72.CrossRefGoogle ScholarPubMed
Zhang, R. G., Pappas, T., Brace, J. al. 2002. Structure of a bacterial quorum-sensing transcription factor complexed with pheromone and DNA. Nature 417: 971–4.CrossRefGoogle ScholarPubMed
Zhu, J., Beaber, J. W., Moré, M. al. 1998. Analogs of the autoinducer 3-oxooctanoyl-homoserine lactone strongly inhibit activity of the TraR protein of Agrobacterium tumefaciens. J. Bacteriol. 180: 5398–405.Google ScholarPubMed
Zhu, J., Oger, P. M., Schrammeijer, al. 2000. The bases of crown gall tumorigenesis. J. Bacteriol. 182: 3885–95.CrossRefGoogle ScholarPubMed
Zhu, J. and Winans, S. C. 1998. Activity of the quorum-sensing regulator TraR of Agrobacterium tumefaciens is inhibited by a truncated, dominant defective TraR-like protein. Molec. Microbiol. 27: 289–97.CrossRefGoogle ScholarPubMed
Zhu, J. and Winans, S. C.. 1999. Autoinducer binding by the quorum-sensing regulator TraR increases affinity for target promoters in vitro and decreases TraR turnover rates in whole cells. Proc. Natn. Acad. Sci. USA 96: 4832–7.CrossRefGoogle ScholarPubMed
Zhu, J. and Winans, S. C. 2001. The quorum-sensing transcriptional regulator TraR requires its cognate signaling ligand for protein folding, protease resistance, and dimerization. Proc. Natn. Acad. Sci. USA 98: 1507–12.CrossRefGoogle ScholarPubMed

Save book to Kindle

To save this book to your Kindle, first ensure is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the or variations. ‘’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats