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Agrobacterium Vitis

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Thomas J. Burr – One of the best experts on this subject based on the ideXlab platform.

  • The Ecology of Agrobacterium Vitis and Management of Crown Gall Disease in Vineyards.
    Current topics in microbiology and immunology, 2018
    Co-Authors: Nemanja Kuzmanović, Joanna Puławska, Lingyun Hao, Thomas J. Burr

    Abstract:

    Agrobacterium Vitis is the primary causal agent of grapevine crown gall worldwide. Symptoms of grapevine crown gall disease include tumor formation on the aerial plant parts, whereas both tumorigenic and nontumorigenic strains of A. Vitis cause root necrosis. Genetic and genomic analyses indicated that A. Vitis is distinguishable from the members of the Agrobacterium genus and its transfer to the genus Allorhizobium was suggested. A. Vitis is genetically diverse, with respect to both chromosomal and plasmid DNA. Its pathogenicity is mainly determined by a large conjugal tumor-inducing (Ti) plasmid characterized by a mosaic structure with conserved and variable regions. Traditionally, A. Vitis Ti plasmids and host strains were differentiated into octopine/cucumopine, nopaline, and vitopine groups, based on opine markers. However, tumorigenic and nontumorigenic strains of A. Vitis may carry other ecologically important plasmids, such as tartrate- and opine-catabolic plasmids. A. Vitis colonizes vines endophytically. It is also able to survive epiphytically on grapevine plants and is detected in soil exclusively in association with grapevine plants. Because A. Vitis persists systemically in symptomless grapevine plants, it can be efficiently disseminated to distant geographical areas via international trade of propagation material. The use of healthy planting material in areas with no history of the crown gall represents the crucial measure of disease management. Moreover, biological control and production of resistant grape varieties are encouraging as future control measures.

  • The Impacts of Tumorigenic and Nontumorigenic Agrobacterium Vitis Strains on Graft Strength and Growth of Grapevines.
    Plant disease, 2017
    Co-Authors: Lingyun Hao, Didem Canik Orel, David J. Kemmenoe, Thomas J. Burr

    Abstract:

    The effects of tumorigenic and non-tumorigenic strains of Agrobacterium Vitis on graft strength and growth of grapevines was studied. A procedure was developed for inoculating graft interface surfaces with A. Vitis and for measuring the force required to break grafts at different time points. Cuttings were soaked in an aqueous suspension of bacteria, about 10^6 CFU/mL, and bacteria were spread onto the graft interface during the grafting procedure. Tumorigenic strain CG49 caused reduced bud germination and increased callus (crown gall) at the graft union and at the base of cuttings at 30 days postinoculation (d.p.i) and significantly reduced shoot growth by 60 d.p.i. whereas at the same time points non-tumorigenic strain, F2/5, inhibited callus formation but did not affect bud germination or shoot growth. Graft strength was enhanced at 30 d.p.i with CG49 presumably because the crown gall callus served to secure the union; graft strength was weakened by F2/5 over the same period. Between 30 and 60 days d.p…

  • Identifying Environmental Sources of Agrobacterium Vitis in Vineyards and Wild Grapevines
    American Journal of Enology and Viticulture, 2017
    Co-Authors: Didem Canik Orel, C. L. Reid, Marc Fuchs, Thomas J. Burr

    Abstract:

    Agrobacterium Vitis, the primary cause of grape crown gall disease, is known to survive internally in grapevines and to spread in propagation material. In this study, we showed that the bacterium can be detected in dormant grape buds and on surfaces of leaves collected from commercial vineyards. Using a highly selective and sensitive method based on magnetic capture hybridization (MCH) together with real-time PCR, we detected A. Vitis in as much as 90% of dormant bud samples and in up to 40% of leaf samples from individual vineyards. The highest percentages of detection occurred in samples collected from vineyards with high incidences of crown gall. A. Vitis was also detected in 22% of wild grapevines (Vitis riparia) collected in New York and in 25% of feral grapevines that included V. californica in California. Several of these vines were growing more than 2 km from commercial vineyards, demonstrating that wild grapevines can serve as a significant inoculum reservoir. The specificity of the MCH and real-time PCR assay used to detect tumorigenic A. Vitis in the environment was further demonstrated by the finding that 69 nontumorigenic strains from regions across the United States did not amplify a virD2 PCR product.

T. J. Burr – One of the best experts on this subject based on the ideXlab platform.

  • Inhibition of crown gall induction by Agrobacterium Vitis strain F2/5 in grapevine and Ricinus
    Vitis: Journal of Grapevine Research, 2015
    Co-Authors: S. Zäuner, J. E. Crespan, T. J. Burr, C. I. Ullrich

    Abstract:

    Biological control measures to prevent or reduce Agrobacterium Vitis -caused losses in grapevine cultures are a worldwide increasing challenge. In the present study, tumour development in grapevine ( Vitis vinifera L.) was induced in the sensitive cv. Kerner by infection with Agrobacterium Vitis strain K306, carrying the p35S gus -int plasmid with the gus gene as marker for transformation by the wild-type T-DNA. Pre-inoculation with the non-tumorigenic A. Vitis strain F2/5 prevented tumour induction by K306(p35 gus -int). Strain M1154, a Tn5 mutant of F2/5 in the luxR -like aviR gene, partially reduced the biocontrol efficiency compared to the wild-type F2/5. GUS-labelling by K306 gus was poor in grapevine in contrast to A. tumefaciens 281(p35 gus- int)-induced tumours in Arabidopsis , indicating plant species-dependent variable gus expression. To use the more reliable direct mRNA expression assay by RTPCR, a new experimental plant/ A. Vitis system was established with Ricinus communis as model plant. Ricinus/A. Vitis galls were available within one week after K306 gus inoculation, reached diameters up to 5 cm, and contained more abundant GUS staining. An additional transformation marker, mRNA expression of the T-DNA-located iaaM oncogene, coding auxin synthesis, was apparent only in tumours induced by the wild-type A. Vitis strain K306 in the absence of the gus construct, which is under the control of the strong 35S CaMV promoter. F2/5 pre-inoculation suppressed GUS staining and gus mRNA expression. DAPI staining revealed the loss of vital fluorescent cell nuclei in F2/5-inoculated grapevine tissue and thus inhibition of any successful T-DNA transfer into host cell nuclei. Differentiation of typical circular vessels in globular vascular bundles in M1154-pretreated galls suggests interference with plant auxin metabolism. In conclusion, together with successfully establishing a new experimental model system, Ricinus/A. Vitis , pre-treatment of host tissue with the non-pathogenic strain F2/5 resulted in preventing the integration and expression of the oncogenic T-DNA of A. Vitis strains by locally necrotizing host cell nuclei.

  • inhibition of crown gall induction by Agrobacterium Vitis strain f2 5 in grapevine and ricinus
    Vitis: Journal of Grapevine Research, 2015
    Co-Authors: S. Zäuner, J. E. Crespan, T. J. Burr, C. I. Ullrich

    Abstract:

    Biological control measures to prevent or reduce Agrobacterium Vitis -caused losses in grapevine cultures are a worldwide increasing challenge. In the present study, tumour development in grapevine ( Vitis vinifera L.) was induced in the sensitive cv. Kerner by infection with Agrobacterium Vitis strain K306, carrying the p35S gus -int plasmid with the gus gene as marker for transformation by the wild-type T-DNA. Pre-inoculation with the non-tumorigenic A. Vitis strain F2/5 prevented tumour induction by K306(p35 gus -int). Strain M1154, a Tn5 mutant of F2/5 in the luxR -like aviR gene, partially reduced the biocontrol efficiency compared to the wild-type F2/5. GUS-labelling by K306 gus was poor in grapevine in contrast to A. tumefaciens 281(p35 gus- int)-induced tumours in Arabidopsis , indicating plant species-dependent variable gus expression. To use the more reliable direct mRNA expression assay by RTPCR, a new experimental plant/ A. Vitis system was established with Ricinus communis as model plant. Ricinus/A. Vitis galls were available within one week after K306 gus inoculation, reached diameters up to 5 cm, and contained more abundant GUS staining. An additional transformation marker, mRNA expression of the T-DNA-located iaaM oncogene, coding auxin synthesis, was apparent only in tumours induced by the wild-type A. Vitis strain K306 in the absence of the gus construct, which is under the control of the strong 35S CaMV promoter. F2/5 pre-inoculation suppressed GUS staining and gus mRNA expression. DAPI staining revealed the loss of vital fluorescent cell nuclei in F2/5-inoculated grapevine tissue and thus inhibition of any successful T-DNA transfer into host cell nuclei. Differentiation of typical circular vessels in globular vascular bundles in M1154-pretreated galls suggests interference with plant auxin metabolism. In conclusion, together with successfully establishing a new experimental model system, Ricinus/A. Vitis , pre-treatment of host tissue with the non-pathogenic strain F2/5 resulted in preventing the integration and expression of the oncogenic T-DNA of A. Vitis strains by locally necrotizing host cell nuclei.

  • Novel pathogen-specific primers for the detection of “Agrobacterium Vitis” and “Agrobacterium tumefaciens”
    Vitis: Journal of Grapevine Research, 2008
    Co-Authors: F. Bini, C. Bazzi, L Otten, T. J. Burr, Anett Kuczmog, Péter Putnoky, Erno Szegedi

    Abstract:

    To detect agrobacteria causing crown gall disease of grapevine novel virulence and oncogene specific primer combinations were tested on Agrobacterium Vitis and Agrobacterium tumefaciens strains including most opine types found in grapevines. Reproducible detection of all the tested pathogens in a single reaction was only possible with multiplex PCR using mixtures of virulence-, or oncogene specific primers. A primer combination including pehA, virF and virD2 gene-specific oligonucleotides amplified the corresponding fragments from nearly all strains included and distinguished A. Vitis and A. tumefaciens strains carrying octopine or nopaline pTis and A. Vitis vitopine strains. A second set of primers designed to amplify the T-DNA auxin genes iaaH and iaaM detected all of the tested pathogens and, as in the case of virF- , and virD2- specific primers, A. Vitis vitopine strains formed also a distinct group. These data were further confirmed using opine synthase-, or 6b gene-specific primers that also allowed the identification and distinction of octopine and nopaline as well as vitopine isolates of A. Vitis . Thus, a wide range of agrobacteria occurring on grapevine were detected and identified. On the other hand, our results confirm that vitopine-type agrobacteria form a distinct group within the genus Agrobacterium .

Leon Otten – One of the best experts on this subject based on the ideXlab platform.

  • Tartrate utilization genes promote growth of Agrobacterium spp. on grapevine
    Molecular Plant-Microbe Interactions®, 1998
    Co-Authors: J. Y. Salomone, Erno Szegedi, P. Cobanov, Leon Otten

    Abstract:

    Crown gall on grapevine is mainly caused by Agrobacterium Vitis, which metabolizes tartrate. Competition experiments between a tartrate-utilizing strain and its non-utilizing derivative showed that tartrate utilization confers a selective advantage on grapevine.

  • Major differences between the rrnA operons of two strains of Agrobacterium Vitis.
    Archives of microbiology, 1996
    Co-Authors: Leon Otten, P. De Ruffray

    Abstract:

    The sequence of the rrnA operon and its flanking regions was determined for the Agrobacterium Vitis type strain NCPPB3554. Compared to the earlier obtained rrnA sequence of A. Vitis strain S4, several important differences were noted: the sequences diverged at the 5′-flanking region, within the 16S–23S intergenic region, and within the 23S rRNA sequence. The B8 stem-loop structure at the 5′-end of the 23S rRNA of strain NCPPB3554 was 142 nt shorter than that of strain S4. These findings have important consequences for the use of ribosomal RNA gene sequences in phylogenetic comparisons.

  • Characterization and distribution of tartrate utilization genes in the grapevine pathogen Agrobacterium Vitis.
    Molecular Plant-microbe Interactions, 1996
    Co-Authors: J. Y. Salomone, P. Crouzet, De Ruffray P, Leon Otten

    Abstract:

    Agrobacterium Vitis is a common pathogen of grapevine. Most strains utilize tartrate, an abundant compound in grapevine. Strain AB3 carries two tartrate utilization (or TAR) regions: TAR-I (on the large pTrAB3 plasmid) and TAR-II (on the AB3 Ti plasmid). TAR-I and TAR-II were structurally and functionally analyzed and are similar to the TAR-III region from the tartrate utilization plasmid pTrAB4 of the nopaline-type A. Vitis strain AB4 (Crouzet and Otten, J. Bacteriol. 1995, 177:6518-6526). The minimal tartrate utilization region of TAR-I contains four genes (ttuA-ttuD). The ttuC gene is homologous to the tartrate dehydrogenase gene from Pseudomonas putida. Outside the minimal region a second ttuC-like gene is found (ttuC’) which is transcribed and complements a ttuC mutant. Most grapevine isolates carry one or two of the three characterized TAR regions and show a considerable degree of polymorphism around these regions.