Letter | Published:

Agrobacterium conjugation and gene regulation by N-acyl-L-homoserine lactones

Nature volume 362, pages 446448 (01 April 1993) | Download Citation



CONJUGAL opines secreted by crown gall tumours induce strains of Agrobacterium tumefaciens that are donors of Ti plasmids to produce a diffusible conjugation factor1. This enhances the conjugal transfer efficiency of the Ti plasmid in other strains of A. tumefaciens. This factor behaves as a secondary messenger, transmitting the environmental information to tra genes. Here we report the use of spectrometry to show that this factor is identical to synthetic N-(β-oxo-octan-l-oyl)-L-homoserine lactone and confirm that the synthetic compound is biologically active. N-(Hexan-l-oyl)-L-homoserine lactone has also been detected. A closely related molecule, N-(β-oxo-hexan-l-oyl)-L-homoserine lactone, autoinduces bioluminescence in the distantly related bacterium, Vibriofischeri2. N-Acyl-homoserine lactones thus seem to be conserved molecules in which the length and nature of the lipophilic acyl chain determines the biological function to be regulated. Mutants that do not produce the factor fail to conjugate unless supplied with it in the induction medium (our unpublished data). These data indicate that the conjugation factor is an autoinducer and a key signal molecule in the conjugation system of A. tumefaciens. It is, to our knowledge, the first example of a second messenger molecule in a bacterial conjugation system.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    & J. Bact. 173, 1867–1872 (1991).

  2. 2.

    et al. Biochemistry 20, 2444–2449 (1981).

  3. 3.

    , & Nature 362, 448–450 (1993).

  4. 4.

    , , & Arch. Microbiol. 146, 35–40 (1986).

  5. 5.

    et al. Gene 116, 87–91 (1992).

  6. 6.

    & J. biol. Chem. 264, 21670–21676 (1989).

  7. 7.

    & Molec. gen. Genet. 167, 147–155 (1978).

  8. 8.

    , & J. org. Chem. 43, 2923–2925 (1978).

  9. 9.

    Experiments in Molecular Genetics 352–359 (Cold Spring Harbor Laboratory Press, New York, 1972).

  10. 10.

    , & J. org. Chem. 43, 2087–2088 (1978).

  11. 11.

    , , & EMB0 J. 4, 891–898 (1985).

Download references

Author information


  1. Department of Crop Protection, Waite Agricultural Research Institute, The University of Adelaide, Glen Osmond, South Australia, Australia 5064

    • Lianhui Zhang
    • , Peter J. Murphy
    •  & Allen Kerr
  2. Department of Plant Science, Waite Agricultural Research Institute, The University of Adelaide, Glen Osmond, South Australia, Australia 5064

    • Max E. Tate
  3. To whom correspondence should be addressed.

    • Max E. Tate


  1. Search for Lianhui Zhang in:

  2. Search for Peter J. Murphy in:

  3. Search for Allen Kerr in:

  4. Search for Max E. Tate in:

About this article

Publication history






Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.