Chapter 15 : Diverse Roles of Agrobacterium Ti Plasmid-Borne Genes in the Formation and Colonization of Plant Tumors

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This chapter describes the various steps in plant colonization, including binding of the bacteria to host cells, recognition of diffusible host-released chemical signals, and processing and transfer of oncogenic DNA (T-DNA). It includes a discussion on the utilization of tumor-released compounds called opines and on the horizontal transfer of the Ti plasmid. Species of have been classified primarily by their phytopathogenic properties, which are largely due to differences in plasmid content. With respect to chromosomally encoded properties, and are well-defined separate taxa whereas , , and are not. The most thoroughly studied strains contain either octopine-type or nopaline-type Ti plasmids. Virtually all genes found on Ti plasmids play direct or indirect roles in some aspect of crown gall tumorigenesis or tumor colonization. VirD4 is absolutely required for transfer and pilus formation. Some members of the regulon are not essential for tumorigenesis and may play other roles in pathogenesis. Since Ti plasmids encode both TraI and TraR, each conjugal donor takes a census of other donors rather than of recipients. It is a challenge even to speculate about the adaptive value of such a system. The observation that two opines regulate conjugation in opposite ways is equally perplexing.

Citation: Winans S, Kalogeraki V, Jafri S, Akakura R, Xia Q. 1999. Diverse Roles of Agrobacterium Ti Plasmid-Borne Genes in the Formation and Colonization of Plant Tumors, p 289-307. In Kaper J, Hacker J (ed), Pathogenicity Islands and Other Mobile Virulence Elements. ASM Press, Washington, DC. doi: 10.1128/9781555818173.ch15
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Image of Figure 1
Figure 1

Genetic map of an octopine-type Ti plasmid, pTiΔ6. TL-DNA and TR-DNA, two DNA fragments transferred to plant nuclei; ,and . VirG-regulated operons that are essential for efficient plant tumorigenesis; ,and VirG-regulated operons that are not required for tumorigenesis; and , operons required for Ti plasmid conjugal transfer; ,and ,regulatory genes that control the expression of the and operons; and , genes required for catabolism of octopine; , an ATP-binding cassette-type transporter for an unknown substrate; , , , and,operons required for catabolism of mannopine, agropine, agropinic acid, and mannopinic acid, respectively; ,gene required for vegetative plasmid replication.

Citation: Winans S, Kalogeraki V, Jafri S, Akakura R, Xia Q. 1999. Diverse Roles of Agrobacterium Ti Plasmid-Borne Genes in the Formation and Colonization of Plant Tumors, p 289-307. In Kaper J, Hacker J (ed), Pathogenicity Islands and Other Mobile Virulence Elements. ASM Press, Washington, DC. doi: 10.1128/9781555818173.ch15
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Image of Figure 2
Figure 2

Two-way exchange of chemical signals between agrobacteria and host plants. Host-released chemical signals (including phenolic compounds, monosaccharides, and acidity) are perceived by the VirA to VirG proteins, which transcribe promoters. T-DNA is nicked by VirD2, and single-stranded, linear T-strands are formed by strand displacement. T-strands and VirE2 separately exit the bacteria via a conjugal pore encoded by the operon, and they form a T-complex within the plant cytoplasm. T-complexes are transported into the nucleoplasm via two classes of host transport proteins, and the T-DNA is integrated into genomic DNA. For the sake of clarity, the relative orientations of genes and T-DNA have been inverted.

Citation: Winans S, Kalogeraki V, Jafri S, Akakura R, Xia Q. 1999. Diverse Roles of Agrobacterium Ti Plasmid-Borne Genes in the Formation and Colonization of Plant Tumors, p 289-307. In Kaper J, Hacker J (ed), Pathogenicity Islands and Other Mobile Virulence Elements. ASM Press, Washington, DC. doi: 10.1128/9781555818173.ch15
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Figure 3

Cell density-dependent expression of the Ti plasmid regulon. The gene regulator TraR is synthesized in response to host-released opines. At high cell densities, TraR binds the pheromone 3-oxo-C-HSL and activates the transcription of other and promoters. TraR activity is antagonized by TraM and by TrlR. is part of the regulon, resulting in negative autoregulation, while is induced in response to host-released mannopine. The role of MocR in the regulation of and is speculative.

Citation: Winans S, Kalogeraki V, Jafri S, Akakura R, Xia Q. 1999. Diverse Roles of Agrobacterium Ti Plasmid-Borne Genes in the Formation and Colonization of Plant Tumors, p 289-307. In Kaper J, Hacker J (ed), Pathogenicity Islands and Other Mobile Virulence Elements. ASM Press, Washington, DC. doi: 10.1128/9781555818173.ch15
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1. Akiyoshi, D. E.,, D. A. Regier,, and M. P. Gordon. 1987. Cytokinin production by Agrobacterium and Pseudomonas spp. J. Bacteriol. 169: 4242 4248.
2. Akiyoshi, D. E.,, D. A. Regier,, G. Jen,, and M. P. Gordon. 1985. Cloning and nucleotide sequence of the tzs gene from Agrobacterium tumefaciens strain T37. Nucleic Acids Res. 13: 2773 2788.
3. Akopyants, N. S.,, S. W. Clifton,, D. Kersulyte,, J. E. Crabtree,, B. E. Youree,, C. A. Reece,, N. O. Bukanov,, E. S. Drazek,, B. A. Roe,, and D. E. Berg. 1998. Analyses of the cag pathogenicity island of Helicobacter pylori. Mol. Microbiol. 28: 37 53.
4. Albright, L. M.,, M. F. Yanofsky,, B. Leroux,, D. Q. Ma,, and E. W. Nester. 1987. Processing of the T-DNA of Agrobacterium tumefaciens generates border nicks and linear, single-stranded T-DNA. J. Bacteriol. 169: 1046 1055.
5. Alt-Mörbe, J.,, J. L. Stryker,, C. Fuqua,, S. K. Farrand,, and S. C. Winans. 1996. The conjugal transfer system of A. 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 4257.
6. Anderson, L. B.,, A. V. Hertzel,, and A. Das. 1996. Agrobacterium tumefaciens VirB7 and VirB9 form a disulfide-linked protein complex. Proc. Natl. Acad. Sci. USA 93: 8889 8894.
7. Ankenbauer, R. G.,, and E. W. Nester. 1990. Sugar-mediated induction of Agrobacterium tumefaciens virulence genes: structural specificity and activities of monosaccharides. J. Bacteriol. 172: 6442 6446.
8. Aoyama, T.,, M. Takanami,, Ê. Makino,, and A. Oka. 1991. Cross-talk between the virulence and phosphate regulons of Agrobacterium tumefaciens caused by an unusual interaction of the transcriptional activator with a regulatory DNA element. Mol. Gen. Genet. 227: 385 390.
9. Aoyama, T.,, M. Takanami,, and A. Oka. 1989. Signal structure for transcriptional activation in the upstream regions of virulence genes on the hairy-root-inducing plasmid A4. Nucleic Acids Res. 17: 8711 8725.
10. Arico, B.,, J. F. Miller,, C. Roy,, S. Stibitz,, D. Monack,, S. Falkow,, R. Gross,, and R. Rappuoli. 1989. Sequences required for expression of Bordetella pertussis virulence factors share homology with prokaryotic signal transduction proteins. Proc. Natl. Acad. Sci. USA 86: 6671 6675.
11. Ballas, N.,, and V. Citovsky. 1997. Nuclear localization signal binding protein from Arabidopsis mediates nuclear import of Agrobacterium VirD2 protein. Proc. Natl. Acad. Sci. USA 94: 10723 10728.
12. Banta, L. M.,, R. D. Joerger,, V. R. Howitz,, A. M. Campbell,, and A. N. Binns. 1994. Glu-255 outside the predicted ChvE binding site in VirA is crucial for sugar enhancement of acetsyringone perception by Agrobacterium tumefaciens. J. Bacteriol. 176: 3242 3249.
13. Baron, C.,, Y. R. Thorstenson,, and P. C. Zambryski. 1997. The lipoprotein VirB7 interacts with VirB9 in the membranes of Agrobacterium tumefaciens. J. Bacteriol. 179: 1211 1218.
14. Beck von Bodman, S.,, G. T. Hayman,, and S. K. Farrand. 1992. Opine catabolism and conjugal transfer of the nopaline Ti plasmid pTiC58 are coordinately regulated by a single repressor. Proc. Natl. Acad. Sci. USA 89: 643 647.
15. Beijersbergen, A.,, A. Den Dulk-Ras,, R. A. Shilperoort,, and P. J. J. Hooykaas. 1992. Conjugative transfer by the virulence system of Agrobacterium tumefaciens. Science 256: 1324 1327.
16. Berger, B. R.,, and P. J. Christie. 1994. Genetic complementation analysis of the Agrobacterium tumefaciens virB operon: virB2 through virB11 are essential virulence genes. J. Bacteriol. 176: 3646 3660.
17. Bevan, M. W.,, and M.-D. Chilton. 1982. T-DNA of the Agrobacterium Ti and Ri plasmids. Annu. Rev. Genet. 16: 357 384.
18. Bittinger, M. A.,, J. L. Milner,, B. J. Seville,, and J. Handelsman. 1997. rosR, a determinant of nodulation competitiveness in Rhizobium etli. Mol. Plant-Microbe Interact. 10: 180 186.
19. Braun, A. C. 1958. A physiological basis for autonomous growth of crown gall tumor cell. Proc. Natl. Acad. Sci. USA 44: 344 349.
20. Bruce, W. B.,, and W. B. Gurley. 1987. Functional domains of a T-DNA promoter active in crown gall tumors. Mol. Cell. Biol. 7: 59 67.
21. Canaday, J.,, J. C. Gerad,, P. Crouzet,, and L. Otten. 1992. Organization and functional analysis of three T-DNAs from the vitopine Ti plasmid pTiS4. Mol. Gen. Genet. 235: 292 303.
22. Cangelosi, G. A.,, R. G. Ankenbauer,, and E. W. Nester. 1990. Sugars induce the Agrobacterium virulence genes through a periplasmic binding protein and a transmembrane signal protein. Proc. Natl. Acad. Sci. USA 87: 6708 6712.
23. Cangelosi, G. A.,, L. Huang,, V. Puvanesarajah,, G. Stacey,, D. A. Ozga,, J. A. Leigh,, and E. W. Nester. 1987. Common loci for Agrobacterium tumefaciens and Rhizobium meliloti exopolysaccharide synthesis and their roles in plant interactions. J. Bacteriol. 169: 2086 2091.
24. Chang, C. H.,, and S. C. Winans. 1992. Functional roles assigned to the periplasmic, linker, and receiver domains of the Agrobacterium tumefaciens VirA protein. J. Bacteriol. 174: 7033 7039.
25. Charles, T. C.,, and E. W. Nester. 1993. A chromosomally encoded two-component sensory transduction system is required for virulence of Agrobacterium tumefaciens. J. Bacteriol. 175: 6614 6625.
26. Chen, C. Y.,, and C. I. Kado. 1994. Inhibition of Agrobacterium tumefaciens oncogenicity by the osa gene of pSa. J. Bacteriol. 176: 5697 5703.
27. Chilton, M.-D.,, M. H. Drummond,, D. J. Merlo,, D. Sciaky,, A. L. Montoya,, M. P. Gordon,, and E. W. Nester. 1977. Stable incorporation of plasmid DNA into higher plant cells: the molecular basis of crown gall tumorigenesis. Cell 11: 263 271.
28. Chou, A. Y.,, J. Archdeacon,, and C. I. Kado. 1998. Agrobacterium transcriptional regulator Ros is a prokaryotic zinc finger protein that regulates the plant oncogene ipt. Proc. Natl. Acad. Sci. USA 95: 5293 5298.
29. Christie, P. J. 1997. Agrobacterium tumefaciens T-complex transport apparatus: a paradigm for a new family of multifunctional transporters in eubacteria. J. Bacteriol. 179: 3085 3094.
30. Christie, P. J.,, J. E. Ward Jr.,, M. P. Gordon,, and E. W. Nester. 1989. A gene required for transfer of T-DNA to plants encodes an ATPase with autophosphorylating activity. Proc. Natl. Acad. Sci. USA 86: 9677 9681.
31. Christie, P. J.,, W. E. Ward,, S. C. Winans,, and E. W. Nester. 1988. The Agrobacterium tumefaciens virE2 gene product is a single-stranded-DNA-binding protein that associates with T-DNA. J. Bacteriol. 170: 2659 2667.
32. Citovsky, V.,, B. Guralnick,, M. N. Simon,, and J. S. Wall. 1997. The molecular structure of Agrobacterium VirE2-single stranded DNA complexes involved in nuclear import. J. Mol. Biol. 5: 718 727.
33. Citovsky, V.,, M. L. Wong,, and P. Zambryski. 1989. Cooperative interaction of Agrobacterium VirE2 protein with single-stranded DNA: implications for the T-DNA transfer process. Proc. Natl. Acad. Sci. USA 86: 1193 1197.
34. Citovsky, V.,, J. Zupan,, D. Warnick,, and P. Zambryski. 1992. Nuclear localization of Agrobacterium VirE2 protein in plant cells. Science 256: 1802 1805.
35. Close, T. J.,, P. M. Rogowsky,, C. I. Kado,, S. C. Winans,, M. F. Yanofsky,, and E. W. Nester. 1987. Dual control of Agrobacterium tumefaciens Ti plasmid virulence genes. J. Bacteriol. 169: 5113 5118.
36. Cook, D. M.,, P.-L. Li,, F. Ruchaud,, S. Padden,, and S. K. Farrand. 1997. Ti plasmid conjugation is independent of vir: reconstitution of the tra functions from pTiC58 as a binary system. J. Bacteriol. 179: 1291 1297.
37. Cornells, G. R.,, and H. Wolf-Watz. 1997. The Yersinia Yop virulon: a bacterial system for subverting eukaryotic cells. Mol. Microbiol. 23: 861 867.
38. Costacurta, A.,, and J. Vanderleyden. 1995. Synthesis of phytohormones by plant-associated bacteria. Crit. Rev. Microbiol. 21: 1 18.
39. Dang, T. A.,, and P. J. Christie. 1997. The VirB4 ATPase of Agrobacterium tumefaciens is a cytoplasmic membrane protein exposed at the periplasmic surface. J. Bacteriol. 179: 453 462.
40. de Groot, M. J.,, P. Bundock,, P. J. Hooykaas,, and A. G. Beijersbergen. 1998. Agrobacterium tumefaciens-mediated transformation of filamentous fungi. Nat. Biotechnol. 16: 839 842.
41. Deng, W.,, L. Chen,, D. W. Wood,, T. Metcalfe,, X. Liang,, M. P. Gordon,, L. Cornai,, and E. W. Nester. 1998. Agrobacterium VirD2 protein interacts with plant host cyclophilins. Proc. Natl. Acad. Sci. USA 95: 7040 7045.
42. De Pater, B. S.,, M. P. Klinkhamer,, P. A. Amesz,, R. J. de Kam,, J. Memelink,, J. H. Hoge,, and R. A. Schilperoort 1987. Plant expression signals of the Agrobacterium T-cyt gene. Nucleic Acids Res. 15: 8267 8281.
43. Dessaux, Y.,, A. Petit,, and J. Tempe,. 1992. Opines in Agrobacterium biology, p. 109 136. In D. P. S. Verma (ed.), Molecular Signals in Plant-Microbe Communications. CRC Press, Inc., Ann Arbor, Mich.
44. Dombek, P.,, and W. Ream. 1997. Functional domains of Agrobacterium tumefaciens single-stranded DNA-binding protein VirE2. J. Bacteriol. 179: 1165 1173.
45. Doty, S. L.,, M. Chang,, and E. W. Nester. 1993. The chromosomal virulence gene chvE of Agrobacterium tumefaciens is regulated by a LysR family member. J. Bacteriol. 175: 7880 7886.
46. Doty, S. L.,, M. C. Yu,, J. I. Lundin,, J. D. Heath,, and E. W. Nester. 1996. Mutational analysis of the input domain of the VirA protein of Agrobacterium tumefaciens. J. Bacteriol. 178: 961 970.
47. Douglas, C. J.,, R. J. Staneloni,, R. A. Rubin,, and E. W. Nester. 1985. Identification and genetic analysis of an Agrobacterium tumefaciens chromosomal virulence region. J. Bacteriol. 161: 850 860.
48. Farrand, S. K., 1993. Conjugal transfer oi Agrobacterium plasmids, p. 255 291. In D. B. Clewell (ed.), Bacterial Conjugation. Plenum Press, New York, N.Y.
49. Farrand, S. K.,, I. Hwang,, and D. M. Cook. 1996. The tra region of the nopaline-type Ti plasmid is a chimera with elements related to the transfer systems of RSF1010, RP4, and F. J. Bacteriol. 178: 4233 4247.
50. Fullner, K. J.,, J. C. Lara,, and E. W. Nester. 1996. Pilus assembly by Agrobacterium T-DNA transfer genes. Science 273: 1107 1109.
51. Fuqua, C.,, M. Burbea,, and S. C. Winans. 1995. Activity of the Agrobacterium Ti plasmid conjugal transfer regulator TraR is inhibited by the product of the traM gene. J. Bacteriol. 177: 1367 1373.
52. Fuqua, C.,, S. C. Winans,, and E. P. Greenberg. 1996. Census and consensus in bacterial ecosystems: the LuxR-LuxI family of quorum-sensing transcriptional regulators. Annu. Rev. Microbiol. 50: 727 751.
53. Fuqua, C.,, and S. C. Winans. 1996. Localization of OccR-activated and TraR-activated promoters that express two ABC-type permeases and the traR gene of Ti plasmid pTiR10. Mol. Microbiol. 20: 1199 1210.
54. Fuqua, C.,, and S. C. Winans. 1996. Conserved cis-acting promoter elements are required for density-dependent transcription of Agrobacterium tumefaciens conjugal transfer genes. J. Bacteriol. 178: 435 440.
55. Fuqua, W. C.,, and S. C. Winans. 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 2806.
56. Genetello, C.,, N. van Larebeke,, M. Holsters,, A. De Picker,, M. van Montagu,, and J. Schell. 1977. Ti plasmids of Agrobacterium as conjugative plasmids. Nature (London) 265: 561 563.
57. Gubba, S.,, Y. H. Xie,, and A. Das. 1995. Regulation of Agrobacterium tumefaciens virulence gene expression: isolation of a mutation that restores virGD52E function. Mol. Plant-Microbe Interact. 8: 788 791.
58. Guralnick, B.,, G. Thomsen,, and V. Citovsky. 1996. Transport of DNA into the nuclei of Xenopus oocytes by a modified VirE2 protein of Agrobacterium. Plant Cell 8: 363 373.
59. Habeeb, L.,, L. Wang,, and S. C. Winans. 1991. Transcription of the octopine catabolism operon of the Agrobacterium tumor-inducing plasmid pTiA6 is activated by a LysR-type regulatory protein. Mol. Plant-Microbe Interact. 4: 379 385.
60. Hess, K. M.,, M. W. Dudley,, D. G. Lynn,, R. D. Joerger,, and A. N. Binns. 1991. Mechanism of phenolic activation of Agrobacterium virulence genes: development of a specific inhibitor of bacterial sensor/response systems. Proc. Natl. Acad. Sci. USA 88: 7854 7858.
61. Howard, E. A.,, J. R. Zupan,, V. Citovsky,, and P. C. Zambryski. 1992. The VirD2 protein of A. tumefaciens contains a C-terminal bipartite nuclear localization signal: implications for nuclear uptake of DNA in plant cells. Cell 68: 109 118.
62. Hrabak, E. M.,, and D. K. Willis. 1992. The lemA gene required for pathogenicity of Pseudomonas syringae pv. syringae on bean is a member of a family of two-component regulators. J. Bacteriol. 14: 3011 3020.
63. Huang, M. L.,, G. A. Cangelosi,, W. Halperin,, and E. W. Nester. 1990. A chromosomal Agrobacterium tumefaciens gene required for effective plant signal transduction. J. Bacteriol. 172: 1814 1822.
64. Huang, Y.,, P. Morel,, B. Powell,, and C. I. Kado. 1990. VirA, a coregulator of Ti-specified virulence genes, is phosphorylated in vitro. J. Bacteriol. 172: 1142 1144.
65. Hwang, I.,, D. M. Cook,, and S. K. Farrand. 1995. A new regulatory element modulates homoserine lactone-mediated autoinduction of Ti plasmid conjugal transfer. J. Bacteriol. 177: 449 458.
66. Hwang, I.,, L. Pei-Li,, L. Zhang,, K. R. Piper,, D. M. Cook,, M. E. Tate,, and S. K. Farrand. 1994. Trai, a Luxl homolog, is responsible for production of conjugation factor, the Ti plasmid N-acylhomoserine lactone autoinducer. Proc. Natl. Acad. Sci. USA 91: 4639 4643.
67. Iuchi, S.,, Z. Matsuda,, T. Fujiwara,, and E. C. Lin. 1990. The arcB gene of Escherichia coli encodes a sensor-regulator protein for anaerobic repression of the arc modulon. Mol. Microbiol. 4: 715 727.
68. Jin, S.,, T. Roitsch,, R. G. Ankenbauer,, M. P. Gordon,, and E. W. Nester. 1990. The VirA protein of Agrobacterium tumefaciens is autophosphorylated and is essential for vir gene regulation. J. Bacteriol. 172: 525 530.
69. Kado, C. I. 1994. Promiscuous DNA transfer system of Agrobacterium tumefaciens: role of the virB operon in sex pilus assembly and synthesis. Mol. Microbiol. 12: 17 22.
70. Kahl, G., 1982. Molecular biology of wound healing: the conditioning phenomenon, p. 211 268. In G. Kahl, and J. S. Schell (ed.), Molecular Biology of Plant Tumors. Academic Press, Inc., New York, N.Y.
71. Kalogeraki, V. S.,, and S. C. Winans. 1998. Wound-released chemical signals may elicit multiple responses from an Agrobacterium tumefaciens strain containing an octopine-type Ti plasmid. J. Bacteriol. 180: 5660 5667.
72. Kanemoto, R. H.,, A. T. Powell,, D. E. Akiyoshi,, D. A. Regier,, R. A. Kerstetter,, E. W. Nester,, M. C. Hawes,, and M. P. Gordon. 1989. Nucleotide sequence and analysis of the plant-inducible locus pinF from Agrobacterium tumefaciens. J. Bacteriol. 171: 2506 2512.
73. Kemner, J. M.,, X. Liang,, and E. W. Nester. 1997. The Agrobacterium tumefaciens virulence gene chvE is part of a putative ABC-type sugar transport operon. J. Bacteriol. 179: 2452 2458.
74. Kerr, A.,, P. Manigault,, and J. Tempe. 1977. Transfer of virulence in vivo and in vitro in Agrobacterium. Nature (London) 265: 560 561.
75. Kersters, K.,, and J. de Ley,. 1984. Genus III. Agrobacterium Conn 1942, 359 AL, p. 244 254. In N. R. Krieg, and J. G. Holt (ed.), Bergey's Manual of Systematic Bacteriology, vol. 1. The Williams & Wilkins Co., Baltimore, Md.
76. Korber, H.,, N. Strizhov,, D. Staiger,, J. Feldwisch,, O. Olsson,, G. Sandberg,, K. Palme,, J. Schell,, and C. Koncz. 1991. T-DNA gene 5 of Agrobacterium modulates auxin response by autoregulated synthesis of a growth hormone antagonist in plants. EMBO J. 10: 3983 3991.
77. Lai, E. M.,, and C. I. Kado. 1998. Processed VirB2 is the major subunit of the promiscuous pilus of Agrobacterium tumefaciens. J. Bacteriol. 180: 2711 2717.
78. Lee, K.,, M. W. Dudley,, K. M. Hess,, D. G. Lynn,, R. D. Joerger,, and A. N. Binns. 1992. Mechanism of activation of Agrobacterium virulence genes: identification of phenol-binding proteins. Proc. Natl. Acad. Sci. USA 89: 8666 8670.
79. Lee, Y. W.,, U. H. Ha,, W. S. Sim,, and E. W. Nester. 1998. Characterization of an unusual sensor gene ( virA) of Agrobacterium. Gene 14: 307 314.
80. Lee, Y.-W.,, S. Jin,, W. S. Sim,, and E. W. Nester. 1996. The sensing of plant signal molecules by Agrobacterium: genetic evidence for direct recognition of phenolic inducers by the VirA protein. Gene 179: 83 88.
81. Lessi, M.,, D. Balzer,, W. Pansegrau,, and E. Lanka. 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 20480.
82. Lessi, M.,, and E. Lanka. 1994. Common mechanisms in bacterial conjugation and Ti-mediated T-DNA transfer to plant cells. Cell 77: 321 324.
83. Lin, T. S.,, and C. I. Kado. 1993. The virD4 gene is required for virulence while virD3 and orf5 are not required for virulence of Agrobacterium tumefaciens. Mol. Microbiol. 9: 803 812.
84. Magrelli, A.,, K. Langenkemper,, C. Dehio,, J. Schell,, and A. Spena. 1994. Splicing of the rolA transcript of Agrobacterium rhizogenes in Arabidopsis. Science 266: 1986 1988.
85. Mantis, N. J.,, and S. C. Winans. 1993. The chromosomal response regulatory gene chvl of Agrobacterium tumefaciens complements an Escherichia coli phoB mutation and is required for virulence. J. Bacteriol. 175: 6626 6636.
86. Matthysse, A. G. 1986. Initial interactions of Agrobacterium tumefaciens with plant host Cells. Crit. Rev. Microbiol. 13: 281 397.
87. Matthysse, A. G.,, and S. McMahan. 1998. Root colonization by Agrobacterium tumefaciens is reduced in cel, att, attD, and attR mutants. Appl. Environ. Microbiol. 64: 2341 2345.
88. Matthysse, A. G.,, D. L. Thomas,, and A. R. White. 1995. Mechanism of Cellulose synthesis in Agrobacterium tumefaciens. J. Bacteriol. 177: 1076 1081.
89. Mayerhofer, R.,, Z. Koncz-Kalman,, C. Nawrath,, G. Bakkeren,, A. Crameri,, K. Angelis,, G. P. Redei,, J. Schell,, B. Hohn,, and C. Koncz. 1991. T-DNA integration: a mode of illegitimate recombination in plants. EMBO J. 10: 697 704.
90. McBride, Ê. E.,, and V. C. Knauf. 1988. Genetic analysis of the virE Operon of the Agrobacterium Ti plasmid pTiA6. J. Bacteriol. 170: 1430 1437.
91. McCleary, W. R.,, and D. R. Zusman. 1990. FrzE of Myxococcus xanthus is homologous to both CheA and CheY of Salmonella typhimurium. Proc. Natl. Acad. Sci. USA 87: 5898 5902.
92. Melchers, L. S.,, T. T. J. Regensburg,, R. B. Bourret,, N. J. Sedee,, R. A. Schiperoort,, and P. J. Hooykaas. 1989. Membrane topology and functional analysis of the sensory protein VirA of Agrobacterium tumefaciens. EMBO J. 8: 1919 1925.
93. Melchers, L. S.,, A. J. G. Regensburg-Tuink,, R. A. Schiperoort,, and P. J. Hooykaas. 1989. Specificity of signal molecules in the activation of Agrobacterium virulence gene expression. Mol. Microbiol. 3: 969 977.
94. Messens, E.,, A. Lenaerts,, M. VanMontagu,, and R. W. Hedges. 1985. Genetic basis for opine secretion from crown gall tumor cells. Mol. Gen. Genet. 199: 344 348.
95. Miranda, A.,, G. Janssen,, L. Hodges,, E. G. Peralta,, and W. Ream. 1992. Agrobacterium tumefaciens transfers extremely long T-DNAs by a unidirectional mechanism. J. Bacteriol. 174: 2288 2297.
96. Moré, M. I.,, L. D. Finger,, J. L. Stryker,, C. Fuqua,, A. Eberhard,, and S. C. Winans. 1996. Enzymatic synthesis of a quorum-sensing autoinducer through use of defined substrates. Science 272: 1655 1658.
97. Morel, P.,, B. S. Powell,, and C. I. Kado. 1990. Demonstration of 3 functional domains responsible for a kinase activity in VirA, a transmembrane sensory protein encoded by the Ti plasmid of Agrobacterium tumefaciens. C. R. Acad. Sci. Ser. III 310: 21 26.
98. Morris, R. O., 1990. Genes specifying auxin and cytokinin biosynthesis in prokaryotes, p. 636 655. In P. J. Davies (ed.), Plant Hormones and Their Role in Plant Growth and Development. Kluwer Academic Publishers, Dordrecht, The Netherlands.
99. Munro, A. W.,, and J. G. Lindsay. 1996. Bacterial cytochromes P-450. Mol. Microbiol. 20: 1115 1125.
100. Mushegian, A. R.,, K. J. Fullner,, E. V. Koonin,, and E. W. Nester. 1996. A family of lysozyme-like virulence factors in bacterial pathogens of plants and animals. Proc. Natl. Acad. Sci. USA 93: 7321 7326.
101. Mysore, K. S.,, B. Bassuner,, X. B. Deng,, N. S. Darbinian,, A. Motchoulski,, W. Ream,, and S. B. Gelvin. 1998. Role of Agrobacterium tumefaciens VirD2 protein in T-DNA transfer and integration. Mol. Plant-Microbe Interact. 11: 668 683.
102. Narasimhulu, S. B.,, X. B. Deng,, R. Sarria,, and S. B. Gelvin. 1996. Early transcription of Agrobacterium T-DNA genes in tobacco and maize. Plant Cell 8: 873 886.
103. Oger, P.,, K.-S. Kim,, R. L. Sackett,, K. R. Piper,, and S. K. Farrand. 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. Mol. Microbiol. 27: 277 288.
104. Okamoto, S.,, A. Toyoda-Yamamoto, Ê. Ito, I. Takebe, and Y. Machida. 1991. Localization and orientation of the VirD4 protein of Agrobacterium tumefaciens in the cell membrane. Mol. Gen. Genet. 228: 24 32.
105. Olson, E. R. 1993. Influence of pH on bacterial gene expression. Mol. Microbiol. 8: 5 14.
106. Ophel, K.,, and A. Kerr. 1990. Agrobacterium vitis sp. nov. for strains of Agrobacterium biovar 3 from grapevines. Int. J. Syst. Bacteriol. 40: 236 241.
107. Pan, S. Q.,, T. Charles,, S. Jin,, Z. L. Wu,, and E. W. Nester. 1993. Preformed dimeric state of the sensor protein VirA is involved in plant- Agrobacterium signal transduction. Proc. Natl. Acad. Sci. USA 90: 9939 9943.
108. Pansegrau, W.,, F. Schoumacher,, B. Hohn,, and E. Lanka. 1993. Site-specific cleavage and joining of single-stranded DNA by VirD2 protein of Agrobacterium tumefaciens Ti plasmids: analogy to bacterial conjugation. Proc. Natl. Acad. Sci. USA 90: 11538 11542.
109. Peng, W. T.,, Y. W. Lee,, and E. W. Nester. 1998. The phenolic recognition profiles of the Agrobacterium tumefaciens VirA protein are broadened by a high level of the sugar binding protein ChvE. J. Bacteriol. 180: 5632 5638.
110. Peralta, E. G.,, and L. W. Ream. 1985. T-DNA border sequences required for crown gall tumorigenesis. Proc. Natl. Acad. Sci. USA 82: 5112 5116.
111. Pohlman, R. F.,, H. D. Genetti,, and S. C. Winans. 1994. Common ancestry between IncN conjugal transfer genes and macromolecular export systems of plant and animal pathogens. Mol. Microbiol. 14: 655 668.
112. Porter, S. G.,, M. F. Yanofsky,, and E. W. Nester. 1987. Molecular characterization of the virD operon from Agrobacterium tumefaciens. Nucleic Acids Res. 15: 7503 7517.
113. Powell, B. S., and Ñ. I. Kado. 1990. Specific binding of VirG to the vir box requires a C-terminal domain and exhibits a minimum concentration threshold. Mol. Microbiol. 4: 2159 2166.
114. Regensburg-Tuink, A. J.,, and P. J. Hooykaas. 1993. Transgenic N. glauca plants expressing bacterial virulence gene virF are converted into hosts for nopaline strains of A. tumefaciens. Nature (London) 363: 69 71.
115. Relic, B.,, M. Andjelkovic,, L. Rossi,, Y. Nagamine,, and B. Hohn. 1998. Interaction of the DNA modifying proteins VirD1 and VirD2 of Agrobacterium tumefaciens: analysis by subcellular localization in mammalian cells. Proc. Natl. Acad. Sci. USA 95: 9105 9110.
116. Rogowski, P. M.,, B. S. Powell,, K. Shirasu,, T.-S. Lin,, P. Morel,, E. M. Zyprian,, T. R. Steck,, and C. I. Kado. 1990. Molecular characterization of the vir regulon of Agrobacterium tumefaciens: complete nucleotide sequence and gene organization of the 28.63 kbp regulon cloned as a single unit. Plasmid 23: 85 106.
117. Roitsch, T.,, H. Wang,, S. G. Jin,, and E. W. Nester. 1990. Mutational analysis of the VirG protein, a transcriptional activator of Agrobacterium tumefaciens virulence genes. J. Bacteriol. 172: 6054 6060.
118. Rossi, L.,, B. Hohn,, and B. Tinland. 1996. Integration of complete transferred DNA units is dependent on the activity of virulence E2 protein of Agrobacterium tumefaciens. Proc. Natl. Acad. Sci. USA 9: 126 130.
119. Salmond, G. P.,, and P. J. Reeves. 1993. Membrane traffic wardens and protein secretion in gram-negative bacteria. Trends Biochem. Sci. 18: 7 12.
120. Sawada, H.,, H. leki,, H. Oyaizu,, and S. Matsumoto. 1993. Proposal for rejection of Agrobacterium tumefaciens and revised descriptions for the genus Agrobacterium and for Agrobacterium radiobacter and Agrobacterium rhizogenes. Int. J. Syst. Bacteriol. 43: 694 702.
121. Scheiffele, P.,, W. Pansegrau,, and E. Lanka. 1995. Initiation of Agrobacterium tumefaciens T-DNA processing. Purified proteins VirD1 and VirD2 catalyze site- and strand-specific cleavage of superhelical T-border DNA in vitro. J. Biol. Chem. 270: 1269 1276.
122. Sen, P.,, G. J. Pazour,, D. Anderson,, and A. Das. 1989. Cooperative binding of Agrobacterium tumefaciens VirE2 protein to single-stranded DNA. J. Bacteriol. 171: 2573 2580.
123. Sheng, J.,, and V. Citovsky. 1996. Agrobacterium-plant cell DNA transport: have virulence proteins, will travel. Plant Cell 8: 1699 1710.
124. Shimoda, N.,, A. Toyoda-Yamamoto,, S. Aoki,, and Y. Machida. 1993. Genetic evidence for an interaction between the VirA sensor protein and the ChvE sugar-binding protein of Agrobacterium. J. Biol. Chem. 268: 26552 26558.
125. Shimoda, N.,, A. Toyoda-Yamamoto,, J. Nagamine,, S. Usami,, M. Katayama,, Y. Sakagami,, and Y. Machida. 1990. Control of expression of Agrobacterium vir genes by synergistic actions of phenolic signal molecules and monosaccharides. Proc. Natl. Acad. Sci. USA 87: 6684 6688.
126. Shirasu, K.,, Z. Koukolikova-Nicola,, B. Hohn,, and C. I. Kado. 1994. An inner-membrane-associated virulence protein essential for T-DNA transfer from Agrobacterium tumefaciens to plants exhibits ATPase activity and similarities to conjugative transfer genes. Mol. Microbiol. 11: 581 588.
127. Shurvington, C. E.,, and W. Ream. 1991. 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.
128. Smith, E. F.,, and C. O. Townsend. 1907. A plant tumor of bacterial origin. Science 25: 671 673.
129. Spencer, P. A.,, and G. H. N. Towers. 1988. Specificity of signal compounds detected by Agrobacterium tumefaciens. Phytochemistry 27: 2781 2785.
130. Spudich, G. M.,, D. Fernandez,, X. R. Zhou,, and P. J. Christie. 1996. Intermolecular disulfide bonds stabilize VirB7 homodimers and VirB7/VirB9 heterodimers during biogenesis of the Agrobacterium tumefaciens T-complex transport apparatus. Proc. Natl. Acad. Sci. USA 93: 7512 7517.
131. Stachel, S. E.,, E. Messens,, M. Van Montagu,, and P. C. Zambryski. 1985. Identification of the signal molecules produced by wounded plant cells that activate T-DNA transfer in Agrobacterium tumefaciens. Nature (London) 318: 624 629.
132. Stachel, S. E.,, B. Timmerman,, and P. Zambryski. 1986. Generation of single-stranded T-DNA molecules during the initial stages of T-DNA transfer from Agrobacterium tumefaciens to plant cells. Nature (London) 322: 706 712.
133. Stachel, S. E.,, B. Timmerman,, and P. Zambryski. 1987. Activation of Agrobacterium tumefaciens vir gene expression generates multiple single-stranded T-strand molecules from the pTiA6 T-region: requirement for 5' virD gene products. EMBO J. 6: 857 863.
134. Stahl, L. E.,, A. Jacobs,, and A. N. Binns. 1998. The conjugal intermediate of plasmid RSF1010 inhibits Agrobacterium tumefaciens virulence and VirB-dependent export of VirE2. J. Bacteriol. 180: 3933 3939.
135. Sundberg, C.,, L. Meek,, K. Carroll,, A. Das,, and W. Ream. 1996. VirEl protein mediates export of the single-stranded DNA-binding protein VirE2 from Agrobacterium tumefaciens into plant cells. J. Bacteriol. 178: 1207 1212.
136. Tait, R. C.,, and C. I. Kado. 1988. Regulation of the virC and virD promoters of pTiC58 by the ros chromosomal mutation of Agrobacterium tumefaciens. Mol. Microbiol. 2: 385 392.
137. Thomashow, M. F.,, J. E. Karlinsey,, J. R. Marks,, and R. E. Hurlbert 1987. Identification of a new virulence locus in Agrobacterium tumefaciens that affects polysaccharide composition and plant cell attachment. J. Bacteriol. 169: 3209 3216.
138. Thomashow, M. F.,, R. Nutter,, A. L. Montoya,, M. P. Gordon,, and E. W. Nester. 1980. Integration and organization of Ti plasmid sequences in crown gall tumors. Cell 19: 729 739.
139. Tinland, B.,, and B. Hohn. 1995. Recombination between prokaryotic and eukaryotic DNA: integration of Agrobacterium tumefaciens T-DNA into the plant genome. Genet. Eng. 17: 209 229.
140. Tinland, B.,, P. Fournier,, t. Heckel,, and L. Otten. 1992. Expression of a chimaeric heat-shock-inducible Agrobacterium 6b oncogene in Nicotiana rustica. Plant Mol. Biol. 18: 921 930.
141. Turk, S. C.,, L. S. Melchers,, H. den Dulk-Ras,, T. A. J. Regensburg,, and P. J. Hooykaas. 1991. Environmental conditions differentially affect vir gene induction in different Agrobacterium strains. Plant Mol. Biol. 16: 1051 1059.
142. van Larebeke, N.,, C. Genetello,, J. Schell,, R. A. Schilperoort,, A. K. Hermans,, J. P. Hernalsteens,, and M. Van Montagu. 1975. Acquisition of tumor inducing ability by non-oncogenic agrobacteria as a result of plasmid transfer. Nature 255: 742 743.
143. Wagner, V. T.,, and A. G. Matthysse. 1992. Involvement of a vitronectin-like protein in attachment of Agrobacterium tumefaciens to carrot suspension culture cells. J. Bacteriol. 174: 5999 6003.
144. Wang, L.,, J. D. Helmann,, and S. C. Winans. 1992. The A. tumefaciens transcriptional activator OccR causes a bend at a target promoter, which is partially relaxed by a plant tumor metabolite. Cell 69: 659 667.
145. Waters, V. L.,, K. H. Hirata,, W. Pansegrau,, E. Lanka,, and D. G. Guiney. 1991. Sequence identity in the nick regions of IncP plasmid transfer origins and T-DNA borders of Agrobacterium Ti plasmids. Proc. Natl. Acad. Sci. USA 88: 1456 1460.
146. Weiss, A. A.,, F. D. Johnson,, and D. L. Burns. 1993. Molecular characterization of an operon required for pertussis toxin secretion. Proc. Natl. Acad. Sci. USA 90: 2970 2974.
147. Willems, A.,, and M. D. Collins. 1993. Phylogenetic analysis of rhizobia and agrobacteria based on 16S rRNA gene sequences. Int. J. Syst. Bacteriol. 43: 305 313.
148. Winans, S. C.,, S. Jin,, T. Komari,, K. M. Johnson,, and E. W. Nester,. 1987. The role of virulence regulatory loci in determining Agrobacterium host range, p. 573 582. In D. von Wettstein, and N.-H. Chua (ed.), Plant Molecular Biology. Plenum Press, New York, N.Y.
149. Winans, S. C. 1992. Two-way chemical signaling in Agrobacterium-plant interactions. Microbiol. Rev. 56: 12 31.
150. Winans, S. C.,, J. Zhu,, and M. I. Moré,. 1999. Cell density-dependent gene expression by Agrobacterium tumefaciens during colonization of crown gall tumors, p. 117 128. In G. M. Dunny, and S. C. Winans (ed.), Cell-Cell Signaling in Bacteria. ASM Press, Washington, D.C.
151. Yadav, N. S.,, J. Vanderlayden,, D. R. Bennett,, W. M. Barnes,, and M.-D. Chilton. 1982. Short direct repeats flank the T-DNA on a nopaline Ti plasmid. Proc. Natl. Acad. Sci. USA 79: 6322 6326.
152. Yamada, T.,, C. J. Palm,, B. Brooks,, and T. Kosuge. 1985. Nucleotide sequence of the Pseudomonas sevastanoi indoleacetic acid genes show homology with Agrobacterium tumefaciens T-DNA. Proc. Natl. Acad. Sci. USA 82: 6522 6526.
153. Yanofsky, M. F.,, S. G. Porter,, C. Young,, L. M. Albright,, M. P. Gordon,, and E. W. Nester. 1986. The virD operon of Agrobacterium tumefaciens encodes a site-specific endonuclease. Cell 7: 471 477.
154. Young, C.,, and E. W. Nester. 1988. Association of the VirD2 protein with the 5' end of T strands in Agrobacterium tumefaciens. J. Bacteriol. 170: 3367 3374.
155. Zaenen, I.,, N. Van Larebeke,, H. Teuchy,, M. Van Montagu,, and J. Shell. 1974. Supercoiled circular DNA in crown-gall inducing Agrobacterium strains. J. Mol. Biol. 86: 109 127.
156. Zambryski, P.,, J. Tempe,, and J. Schell. 1989. Transfer and function of T-DNA genes from Agrobacterium Ti and Ri plasmids in plants. Cell 27: 193 201.
157. Zhang, L.,, P. J. Murphy,, A. Kerr,, and M. E. Tate. 1993. Agrobacterium conjugation and gene regulation by N-acyl-L-homoserine lactones. Nature (London) 362: 446 448.
158. Zhu, J.,, and S. C. Winans. 1998. Activity of the quorum-sensing regulator TraR of Agrobacterium tumefaciens is inhibited by a truncated, dominant defective TraR-like protein. Mol. Microbiol. 27: 289 297.
158a. Zhu, J.,, and S. C. Winans. 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. Natl. Acad. Sci. USA 96: 4832 4837.
159. Zupan, J. R.,, V. Citovsky,, and P. Zambryski. 1996. Agrobacterium VirE2 protein mediates nuclear uptake of single-stranded DNA in plant cells. Proc. Natl. Acad. Sci. USA 93: 2392 2397.

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