Octopine and nopaline strains of Agrobacterium tumefaciens differ in virulence; molecular characterization of the virF locus - PubMed (original) (raw)
Octopine and nopaline strains of Agrobacterium tumefaciens differ in virulence; molecular characterization of the virF locus
L S Melchers et al. Plant Mol Biol. 1990 Feb.
Abstract
Octopine and nopaline strains of Agrobacterium tumefaciens were found to differ in virulence on Nicotiana glauca. This difference is due to the absence of a functional virF locus, which is necessary for efficient tumorigenesis on N. glauca, from the nopaline Ti plasmids. Genetic studies and DNA sequence analysis of the virF locus revealed that virF embraces one open reading frame coding for a hydrophilic protein with a molecular mass of 22,437 Da. Transcription of virF is directed from left to right, towards the T region, and is strongly induced by the phenolic compound acetosyringone. We established that virA and virG, two genes known to be essential for induction of the vir regulon, are necessary for acetosyringone-induced virF expression, implying that virF is a member of this vir regulon. Agrobacterium virF mutants can be complemented for tumor induction by co-infection with avirulent Agrobacterium 'helper' strains. We found that such 'helper' strains must express not only the virF gene but also the vir operons virA, virB, virD and virG.
References
- Nucleic Acids Res. 1988 May 25;16(10):4621-36 - PubMed
- Cell. 1986 Aug 1;46(3):325-33 - PubMed
- Plant Mol Biol. 1987 Nov;9(6):635-45 - PubMed
- J Mol Biol. 1982 May 5;157(1):105-32 - PubMed
- Nucleic Acids Res. 1986 Jun 11;14(11):4683-90 - PubMed
Publication types
MeSH terms
Substances
LinkOut - more resources
Other Literature Sources