This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kalogeraki, V. S. Articles by Winans, S. C. Search for Related Content PubMed PubMed Citation Articles by Kalogeraki, V. S. Articles by Winans, S. C.

 Previous Article  |  Next Article 

J. Bacteriol., 02 1995, 892-897, Vol 177, No. 4
Copyright © 1995, American Society for Microbiology

The octopine-type Ti plasmid pTiA6 of Agrobacterium tumefaciens contains a gene homologous to the chromosomal virulence gene acvB

VS Kalogeraki and SC Winans
Section of Microbiology, Cornell University, Ithaca, New York 14853.

Although the majority of genes required for the transfer of T-DNA from Agrobacterium tumefaciens to plant nuclei are located on the Ti plasmid, some chromosomal genes, including the recently described acvB gene, are also required. We show that AcvB shows 50% identity with the product of an open reading frame, designated virJ, that is found between the virA and virB genes in the octopine-type Ti plasmid pTiA6. This reading frame is not found in the nopaline-type Ti plasmid pTiC58. acvB is required for tumorigenesis by a strain carrying a nopaline-type Ti plasmid, and virJ complements this nontumorigenic phenotype, indicating that the products of these genes have similar functions. A virJ-phoA fusion expressed enzymatically active alkaline phosphatase, indicating that VirJ is at least partially exported. virJ is induced in a VirA/VirG-dependent fashion by the vir gene inducer acetosyringone. Primer extension analysis and subcloning of the virJ-phoA fusion indicate that the acetosyringone-inducible promoter lies directly upstream of the virJ structural gene. Although the roles of the two homologous genes in tumorigenesis remain to be elucidated, strains lacking acvB and virJ (i) are proficient for induction of the vir regulon, (ii) are able to transfer their Ti plasmids by conjugation, and (iii) are resistant to plant wound extracts. Finally, mutations in these genes cannot be complemented extracellularly.

This article has been cited by other articles:

• Brencic, A., Winans, S. C. (2005). Detection of and Response to Signals Involved in Host-Microbe Interactions by Plant-Associated Bacteria. Microbiol. Mol. Biol. Rev. 69: 155-194 [Abstract] [Full Text]  
• Gelvin, S. B. (2003). Agrobacterium-Mediated Plant Transformation: the Biology behind the "Gene-Jockeying" Tool. Microbiol. Mol. Biol. Rev. 67: 16-37 [Abstract] [Full Text]  
• Peng, W.-T., Banta, L. M., Charles, T. C., Nester, E. W. (2001). The chvH Locus of Agrobacterium Encodes a Homologue of an Elongation Factor Involved in Protein Synthesis. J. Bacteriol. 183: 36-45 [Abstract] [Full Text]  
• Zhu, J., Oger, P. M., Schrammeijer, B., Hooykaas, P. J. J., Farrand, S. K., Winans, S. C. (2000). The Bases of Crown Gall Tumorigenesis. J. Bacteriol. 182: 3885-3895 [Full Text]  
• Kalogeraki, V. S., Zhu, J., Stryker, J. L., Winans, S. C. (2000). The Right End of the vir Region of an Octopine-Type Ti Plasmid Contains Four New Members of the vir Regulon That Are Not Essential for Pathogenesis. J. Bacteriol. 182: 1774-1778 [Abstract] [Full Text]  
• Kalogeraki, V. S., Winans, S. C. (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 [Abstract] [Full Text]