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. 1986 Jul;5(7):1445–1454. doi: 10.1002/j.1460-2075.1986.tb04381.x

The genetic and transcriptional organization of the vir region of the A6 Ti plasmid of Agrobacterium tumefaciens.

S E Stachel, E W Nester
PMCID: PMC1166964  PMID: 3017694

Abstract

The genetic transformation of plant cells by Agrobacterium tumefaciens is mediated by the genes of the Ti plasmid vir region. To determine the genetic and transcriptional organization of the vir region of pTiA6, vir plasmid clones were saturated with insertion mutations of a Tn3-lacZ transposon. This element is both an insertion mutagen and a reporter for the expression of the sequences into which it has inserted. One hundred and twenty-four vir::Tn3-lac insertions were analyzed for their mutagenic effect on Agrobacterium virulence, and for their expression of beta-galactosidase activity, the lacZ gene product, in vegetative bacteria and in bacteria cocultivated with plant cells. These data in conjunction with genetic complementation results show that the pTiA6 vir region contains six distinct vir complementation groups: virA, virB, virC, virD, virE and virG. Mutations in these loci eliminate (virA, virB, virD and virG) or significantly restrict (virC and virE) the ability of Agrobacterium to transform plant cells. Each of the vir loci corresponds to a single vir transcription unit: virA is constitutively expressed and non-inducible; virB, virC, virD and virE are expressed only upon activation by plant cells; and virG is both constitutively expressed and plant-inducible. The two largest vir operons, virB and virD, are probably polycistronic. The pTiA6 vir region also contains plant-inducible loci (pin) which are non-essential for virulence.

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Selected References

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  1. A simple and general method for transferring genes into plants. Science. 1985 Mar 8;227(4691):1229–1231. doi: 10.1126/science.227.4691.1229. [DOI] [PubMed] [Google Scholar]
  2. Birnboim H. C., Doly J. A rapid alkaline extraction procedure for screening recombinant plasmid DNA. Nucleic Acids Res. 1979 Nov 24;7(6):1513–1523. doi: 10.1093/nar/7.6.1513. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Caplan A., Herrera-Estrella L., Inzé D., Van Haute E., Van Montagu M., Schell J., Zambryski P. Introduction of genetic material into plant cells. Science. 1983 Nov 18;222(4625):815–821. doi: 10.1126/science.222.4625.815. [DOI] [PubMed] [Google Scholar]
  4. Chilton M. D., Currier T. C., Farrand S. K., Bendich A. J., Gordon M. P., Nester E. W. Agrobacterium tumefaciens DNA and PS8 bacteriophage DNA not detected in crown gall tumors. Proc Natl Acad Sci U S A. 1974 Sep;71(9):3672–3676. doi: 10.1073/pnas.71.9.3672. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Das A., Stachel S., Ebert P., Allenza P., Montoya A., Nester E. Promoters of Agrobacterium tumefaciens Ti-plasmid virulence genes. Nucleic Acids Res. 1986 Feb 11;14(3):1355–1364. doi: 10.1093/nar/14.3.1355. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Ditta G., Stanfield S., Corbin D., Helinski D. R. Broad host range DNA cloning system for gram-negative bacteria: construction of a gene bank of Rhizobium meliloti. Proc Natl Acad Sci U S A. 1980 Dec;77(12):7347–7351. doi: 10.1073/pnas.77.12.7347. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Douglas C. J., Staneloni R. J., Rubin R. A., Nester E. W. Identification and genetic analysis of an Agrobacterium tumefaciens chromosomal virulence region. J Bacteriol. 1985 Mar;161(3):850–860. doi: 10.1128/jb.161.3.850-860.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Garfinkel D. J., Nester E. W. Agrobacterium tumefaciens mutants affected in crown gall tumorigenesis and octopine catabolism. J Bacteriol. 1980 Nov;144(2):732–743. doi: 10.1128/jb.144.2.732-743.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Garfinkel D. J., Simpson R. B., Ream L. W., White F. F., Gordon M. P., Nester E. W. Genetic analysis of crown gall: fine structure map of the T-DNA by site-directed mutagenesis. Cell. 1981 Nov;27(1 Pt 2):143–153. doi: 10.1016/0092-8674(81)90368-8. [DOI] [PubMed] [Google Scholar]
  10. Gelvin S. B., Gordon M. P., Nester E. W., Aronson A. I. Transcription of the Agrobacterium Ti plasmid in the bacterium and in crown gall tumors. Plasmid. 1981 Jul;6(1):17–29. doi: 10.1016/0147-619x(81)90051-2. [DOI] [PubMed] [Google Scholar]
  11. Hille J., van Kan J., Schilperoort R. trans-Acting virulence functions of the octopine Ti plasmid from Agrobacterium tumefaciens. J Bacteriol. 1984 May;158(2):754–756. doi: 10.1128/jb.158.2.754-756.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Hirsch P. R., Beringer J. E. A physical map of pPH1JI and pJB4JI. Plasmid. 1984 Sep;12(2):139–141. doi: 10.1016/0147-619x(84)90059-3. [DOI] [PubMed] [Google Scholar]
  13. Holsters M., Silva B., Van Vliet F., Genetello C., De Block M., Dhaese P., Depicker A., Inzé D., Engler G., Villarroel R. The functional organization of the nopaline A. tumefaciens plasmid pTiC58. Plasmid. 1980 Mar;3(2):212–230. doi: 10.1016/0147-619x(80)90110-9. [DOI] [PubMed] [Google Scholar]
  14. Hooykaas P. J., Hofker M., den Dulk-Ras H., Schilperoort R. A. A comparison of virulence determinants in an octopine Ti plasmid, a nopaline Ti plasmid, and an Ri plasmid by complementation analysis of Agrobacterium tumefaciens mutants. Plasmid. 1984 May;11(3):195–205. doi: 10.1016/0147-619x(84)90026-x. [DOI] [PubMed] [Google Scholar]
  15. Iyer V. N., Klee H. J., Nester E. W. Units of genetic expression in the virulence region of a plant tumor-inducing plasmid of Agrobacterium tumefaciens. Mol Gen Genet. 1982;188(3):418–424. doi: 10.1007/BF00330043. [DOI] [PubMed] [Google Scholar]
  16. Klee H. J., Gordon M. P., Nester E. W. Complementation analysis of Agrobacterium tumefaciens Ti plasmid mutations affecting oncogenicity. J Bacteriol. 1982 Apr;150(1):327–331. doi: 10.1128/jb.150.1.327-331.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Klee H. J., White F. F., Iyer V. N., Gordon M. P., Nester E. W. Mutational analysis of the virulence region of an Agrobacterium tumefaciens Ti plasmid. J Bacteriol. 1983 Feb;153(2):878–883. doi: 10.1128/jb.153.2.878-883.1983. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Knauf V. C., Nester E. W. Wide host range cloning vectors: a cosmid clone bank of an Agrobacterium Ti plasmid. Plasmid. 1982 Jul;8(1):45–54. doi: 10.1016/0147-619x(82)90040-3. [DOI] [PubMed] [Google Scholar]
  19. Knauf V., Yanofsky M., Montoya A., Nester E. Physical and functional map of an Agrobacterium tumefaciens tumor-inducing plasmid that confers a narrow host range. J Bacteriol. 1984 Nov;160(2):564–568. doi: 10.1128/jb.160.2.564-568.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Lundquist R. C., Close T. J., Kado C. I. Genetic complementation of Agrobacterium tumefaciens Ti plasmid mutants in the virulence region. Mol Gen Genet. 1984;193(1):1–7. doi: 10.1007/BF00327406. [DOI] [PubMed] [Google Scholar]
  21. Ooms G., Klapwijk P. M., Poulis J. A., Schilperoort R. A. Characterization of Tn904 insertions in octopine Ti plasmid mutants of Agrobacterium tumefaciens. J Bacteriol. 1980 Oct;144(1):82–91. doi: 10.1128/jb.144.1.82-91.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Plessis A., Robaglia C., Diolez A., Beyou A., Leach F., Casse-Delbart F., Richaud F. lacZ gene fusions and insertion mutagenesis in the TL-region of Agrobacterium rhizogenes Ri plasmid. Plasmid. 1985 Jul;14(1):17–27. doi: 10.1016/0147-619x(85)90028-9. [DOI] [PubMed] [Google Scholar]
  23. Stachel S. E., An G., Flores C., Nester E. W. A Tn3 lacZ transposon for the random generation of beta-galactosidase gene fusions: application to the analysis of gene expression in Agrobacterium. EMBO J. 1985 Apr;4(4):891–898. doi: 10.1002/j.1460-2075.1985.tb03715.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Stachel S. E., Nester E. W., Zambryski P. C. A plant cell factor induces Agrobacterium tumefaciens vir gene expression. Proc Natl Acad Sci U S A. 1986 Jan;83(2):379–383. doi: 10.1073/pnas.83.2.379. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Wang K., Herrera-Estrella L., Van Montagu M., Zambryski P. Right 25 bp terminus sequence of the nopaline T-DNA is essential for and determines direction of DNA transfer from agrobacterium to the plant genome. Cell. 1984 Sep;38(2):455–462. doi: 10.1016/0092-8674(84)90500-2. [DOI] [PubMed] [Google Scholar]
  26. Zambryski P., Joos H., Genetello C., Leemans J., Montagu M. V., Schell J. Ti plasmid vector for the introduction of DNA into plant cells without alteration of their normal regeneration capacity. EMBO J. 1983;2(12):2143–2150. doi: 10.1002/j.1460-2075.1983.tb01715.x. [DOI] [PMC free article] [PubMed] [Google Scholar]

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