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PMID: 2101693 Published · ppublish English Journal Article Research Support, Non-U.S. Gov't

Octopine and nopaline strains of Agrobacterium tumefaciens differ in virulence; molecular characterization of the virF locus.

Plant molecular biology ·Vol. 14 ·No. 2 ·1990-02-00 ·Pages 249-59

Melchers LS, Maroney MJ, den Dulk-Ras A, Thompson DV, van Vuuren HA, Schilperoort RA, Hooykaas PJ

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.

Related Genes
virF
MeSH Terms
Amino Acid Sequence Arginine/analogs & derivatives,biosynthesis Bacterial Proteins/genetics Base Sequence DNA, Bacterial/genetics Genes, Bacterial Kinetics Molecular Sequence Data Plant Tumors Plants, Toxic Plasmids Protein Conformation Restriction Mapping Rhizobium/genetics,pathogenicity Tobacco/genetics,microbiology Transcription, Genetic Virulence/genetics Virulence Factors
Chemicals
Bacterial Proteins DNA, Bacterial Virulence Factors nopaline octopine Arginine
Authors & Affiliations
7 authors, click to expand affiliations / ORCID
Melchers L S
Department of Plant Molecular Biology, Leiden University, Netherlands.
Maroney M J
den Dulk-Ras A
Thompson D V
van Vuuren H A
Schilperoort R A
Hooykaas P J
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27 references, click to expand
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Article Info
Journal
Plant molecular biology
Abbr.
Plant Mol Biol
ISSN
0167-4412
DOI
10.1007/BF00018565
Published
1990-02-00
Pages
249-59
Language
English
Region
Netherlands
NLM ID
9106343
Subset
IM
Databases
GENBANK
X13981
External Links
PubMed source DOI: 10.1007/BF00018565 View journal details
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