Rapid divergence of Agrobacterium vitis octopine-cucumopine Ti plasmids from a recent common ancestor

Nuenen, Marc van; Ruffray, Patrice de; Otten, Léon

doi:10.1007/bf00276883

Cited by 17 publications

(10 citation statements)

References 33 publications

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“…Ti plasmids from the six A. tumefaciens and eight A. vitis strains analyzed here were previously characterized to some extent at the DNA level, but inducibility of virulence genes by acetosyringone and production of virulence proteins were not analyzed in most cases (24,35,46). Antisera raised by immunization with C58-specific proteins allowed the detection of most virulence proteins in the acetosyringone-induced A. tumefaciens strains (except VirB3, VirB6, and VirD4) and of four virulence proteins in the acetosyringone-induced A. vitis strains (VirB5, VirB7, VirB8, and VirB9).…”

Section: Discussionmentioning

confidence: 99%

Elevated Temperature Differentially Affects Virulence, VirB Protein Accumulation, and T-Pilus Formation in Different Agrobacterium tumefaciens and Agrobacterium vitis Strains

et al. 2001

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That gene transfer to plant cells is a temperature-sensitive process has been known for more than 50 years. Previous work indicated that this sensitivity results from the inability to assemble a functional T pilus required for T-DNA and protein transfer to recipient cells. The studies reported here extend these observations and more clearly define the molecular basis of this assembly and transfer defect. T-pilus assembly and virulence protein accumulation were monitored in Agrobacterium tumefaciens strain C58 at different temperatures ranging from 20°C to growth-inhibitory 37°C. Incubation at 28°C but not at 26°C strongly inhibited extracellular assembly of the major T-pilus component VirB2 as well as of pilus-associated protein VirB5, and the highest amounts of T pili were detected at 20°C. Analysis of temperature effects on the cell-bound virulence machinery revealed three classes of virulence proteins. Whereas class I proteins (VirB2, VirB7, VirB9, and VirB10) were readily detected at 28°C, class II proteins (VirB1, VirB4, VirB5, VirB6, VirB8, VirB11, VirD2, and VirE2) were only detected after cell growth below 26°C. Significant levels of class III proteins (VirB3 and VirD4) were only detected at 20°C and not at higher temperatures. Shift of virulence-induced agrobacteria from 20 to 28 or 37°C had no immediate effect on cell-bound T pili or on stability of most virulence proteins. However, the temperature shift caused a rapid decrease in the amount of cell-bound VirB3 and VirD4, and VirB4 and VirB11 levels decreased next. To assess whether destabilization of virulence proteins constitutes a general phenomenon, levels of virulence proteins and of extracellular T pili were monitored in different A. tumefaciens and Agrobacterium vitis strains grown at 20 and 28°C. Levels of many virulence proteins were strongly reduced at 28°C compared to 20°C, and T-pilus assembly did not occur in all strains except "temperature-resistant" Ach5 and Chry5. Virulence protein levels correlated well with bacterial virulence at elevated temperature, suggesting that degradation of a limited set of virulence proteins accounts for the temperature sensitivity of gene transfer to plants.Growth temperature affects the virulence functions of many pathogenic bacteria. In concert with other stimuli, such as pH and ionic composition of the external medium, temperature shifts modulate virulence gene expression in human and animal pathogenic bacteria, reflecting their adaptation to the host environment (2,14,21,28,36). In the plant pathogen Pseudomonas syringae, a decrease in growth temperature positively correlates with increased virulence gene expression (43,44). In most cases, regulation occurs at the level of gene expression by modulation of the activity of specific two-component regulatory systems or DNA binding of global regulators such as HN-S.Studies early in the last century revealed that tumor formation on wounded and Agrobacterium tumefaciens-infected plants was strongly reduced at temperatures above 29°C compared to 22°C (37). This ...

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Section: Discussionmentioning

confidence: 99%

Elevated Temperature Differentially Affects Virulence, VirB Protein Accumulation, and T-Pilus Formation in Different Agrobacterium tumefaciens and Agrobacterium vitis Strains

et al. 2001

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“…More recently, several other methods have been used to characterize A. vitis. (65,104) but differ in other regions. and 150 strains of Rhizobium and Sinorhizobium.…”

Section: Agrobacterium Vitismentioning

confidence: 90%

“…Jarvis et al (48) used fatty acid analysis to identify species of 65 strains of Agrobacterium spp. Interestingly, the nucleotide sequences of common regions are more than 99.9% homologous, which suggests that the evolution of plasmids proceeds mainly by large-scale events like insertions and deletions (65,71,104). A two-dimensional plot analysis of fatty acid compositions revealed that A. vitis is more similar to Rhizobium galegae than it is to other A. tumefaciens or A. rhizogenes.…”

Section: Agrobacterium Vitismentioning

confidence: 99%

CROWNGALLOFGRAPE: Biology and Disease Management

Burr

Otten

1999

Annu. Rev. Phytopathol.

137

105

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Not until 1973 was it reported that strains of Agrobacterium that cause crown gall disease of grape form a specific group (later characterized as Agrobacterium vitis). Tumorigenic and nontumorigenic A. vitis have since been isolated from infected and symptomless grapes worldwide. Research on the genetic makeup of A. vitis has led to an improved understanding of pathogen biology and bacterial evolution. In addition, the identification of significant gene sequences has facilitated the development of PCR and RFLP-based identification procedures that continue to improve the detection of A. vitis in plants and soil. Current control practices rely on the use of disease-resistant cultivars, cultural practices that minimize plant injury, and the production of pathogen-free vines. Promising future controls include employment of biological control agents and development of crown gall-resistant transgenic grapevines.

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“…Interestingly, the genetic detenninants involved in opine degradation are most often borne on the Ri plasmids. These studies indicate that Ti plasmids have probably evolved as "mosaic" structures, composed of conserved regions (the T -DNA, the virulence genes) and variable regions such as those determining opine degradation (paulus et aI., 1991aVan Nuenen et al, 1993;Otten and De RufIray, 1994). rhizogenes (petit et al, 1983;Jouanin, 1984;Hufmann et al, 1984;Jouanin et al, 1986).…”

Section: Conceptmentioning

confidence: 99%

The Rhizobiaceae

1998

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Rapid divergence of Agrobacterium vitis octopine-cucumopine Ti plasmids from a recent common ancestor

Cited by 17 publications

References 33 publications

Elevated Temperature Differentially Affects Virulence, VirB Protein Accumulation, and T-Pilus Formation in Different Agrobacterium tumefaciens and Agrobacterium vitis Strains

Elevated Temperature Differentially Affects Virulence, VirB Protein Accumulation, and T-Pilus Formation in Different Agrobacterium tumefaciens and Agrobacterium vitis Strains

CROWNGALLOFGRAPE: Biology and Disease Management

The Rhizobiaceae

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