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Thomas J. Burr - One of the best experts on this subject based on the ideXlab platform.
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The Ecology of Agrobacterium Vitis and Management of Crown Gall Disease in Vineyards.
Current topics in microbiology and immunology, 2018Co-Authors: Nemanja Kuzmanović, Joanna Puławska, Lingyun Hao, Thomas J. BurrAbstract: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.
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The Impacts of Tumorigenic and Nontumorigenic Agrobacterium Vitis Strains on Graft Strength and Growth of Grapevines.
Plant disease, 2017Co-Authors: Lingyun Hao, Didem Canik Orel, David J. Kemmenoe, Thomas J. BurrAbstract: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...
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Identifying Environmental Sources of Agrobacterium Vitis in Vineyards and Wild Grapevines
American Journal of Enology and Viticulture, 2017Co-Authors: Didem Canik Orel, C. L. Reid, Marc Fuchs, Thomas J. BurrAbstract: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.
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Distribution of Agrobacterium Vitis in Grapevines and Its Relevance to Pathogen Elimination.
Plant disease, 2016Co-Authors: Kameka L Johnson, C. L. Reid, Heather Cronin, Thomas J. BurrAbstract:Agrobacterium Vitis, the cause of crown gall disease on grapevine, survives internally in vines and can be spread in cuttings for propagation. The possibility of generating pathogen-free vines through tissue culture makes it essential to understand the distribution of the pathogen in grapevines. A highly sensitive magnetic capture hybridization procedure along with real-time polymerase chain reaction were used to measure the distribution of tumorigenic A. Vitis in dormant canes and green shoots of grapevines. Tumorigenic A. Vitis was distributed from the basal to apical nodal and internodal tissues of canes as well as in nonlignified green shoots. In experiments conducted in 2013, A. Vitis was detected in up to 17% of shoot tips and 52% of meristems of greenhouse-grown plants initiated from known A. Vitis-contaminated cuttings. A lower frequency of detection was observed from surface-disinfected shoot tips (7%) as compared with nondisinfected tips (37%), suggesting epiphytic survival on green tissues. In ...
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Inhibition of Grape Crown Gall by Agrobacterium Vitis F2/5 Requires Two Nonribosomal Peptide Synthetases and One Polyketide Synthase.
Molecular plant-microbe interactions : MPMI, 2016Co-Authors: Desen Zheng, Thomas J. BurrAbstract:Agrobacterium Vitis nontumorigenic strain F2/5 is able to inhibit crown gall disease on grapevines. The mechanism of grape tumor inhibition (GTI) by F2/5 has not been fully determined. In this study, we demonstrate that two nonribosomal peptide synthetase (NRPS) genes (F-avi3342 and F-avi5730) and one polyketide synthase gene (F-avi4330) are required for GTI. Knockout of any one of them resulted in F/25 losing GTI capacity. We previously reported that F-avi3342 and F-avi4330 but not F-avi5730 are required for induction of grape tissue necrosis and tobacco hypersensitive response. F-avi5730 is predicted to encode a single modular NRPS. It is located in a cluster that is homologous to the siderophore vicibactin biosynthesis locus in Rhizobium species. Individual disruption of F-avi5730 and two immediate downstream genes, F-avi5731 and F-avi5732, all resulted in reduced siderophore production; however, only F-avi5730 was found to be required for GTI. Complemented F-avi5730 mutant (ΔF-avi5730(+)) restored a wild-type level of GTI activity. It was determined that, over time, populations of ΔF-avi4330, ΔF-avi3342, and ΔF-avi5730 at inoculated wound sites on grapevine did not differ from those of ΔF-avi5730(+) indicating that loss of GTI was not due to reduced colonization of wound sites by mutants.
T. J. Burr - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of crown gall induction by Agrobacterium Vitis strain F2/5 in grapevine and Ricinus
Vitis: Journal of Grapevine Research, 2015Co-Authors: S. Zäuner, J. E. Crespan, T. J. Burr, C. I. UllrichAbstract: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.
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inhibition of crown gall induction by Agrobacterium Vitis strain f2 5 in grapevine and ricinus
Vitis: Journal of Grapevine Research, 2015Co-Authors: S. Zäuner, J. E. Crespan, T. J. Burr, C. I. UllrichAbstract: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.
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Novel pathogen-specific primers for the detection of "Agrobacterium Vitis" and "Agrobacterium tumefaciens"
Vitis: Journal of Grapevine Research, 2008Co-Authors: F. Bini, C. Bazzi, L Otten, T. J. Burr, Anett Kuczmog, Péter Putnoky, Erno SzegediAbstract: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 .
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effect of wound position auxin and Agrobacterium Vitis strain f2 5 on wound healing and crown gall in grapevine
Phytopathology, 2005Co-Authors: J. E. Creasap, C. L. Reid, M. C. Goffinet, R. Aloni, C. Ullrich, T. J. BurrAbstract:ABSTRACT Agrobacterium Vitis is the causal agent of crown gall disease in grapevine, which can be severe in many regions worldwide. Vitis vinifera cultivars are highly susceptible to freeze injury, providing the wounds necessary for infection by A. Vitis. Wound position in relation to the uppermost bud of cuttings was determined to be important in tumor development. Inoculated wounds below buds developed tumors, whereas wounds opposite the bud did not, implying that indole-3-aectic acid flow contributes to tumor formation. If auxin was applied to wounds prior to inoculation with a tumorigenic A. Vitis strain, all sites of inoculation developed tumors, accompanied by an increased amount of callus in the cambium. Wounds inoculated with an A. Vitis biological control strain F2/5 prior to application of the pathogen did not develop galls. A closer examination of these wounds determined that callus cells formed in the cambium during wound healing are susceptible to transformation by the pathogen. Although the ...
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Effect of Wound Position, Auxin, and Agrobacterium Vitis Strain F2/5 on Wound Healing and Crown Gall in Grapevine
Phytopathology, 2005Co-Authors: J. E. Creasap, C. L. Reid, M. C. Goffinet, R. Aloni, C. Ullrich, T. J. BurrAbstract:ABSTRACT Agrobacterium Vitis is the causal agent of crown gall disease in grapevine, which can be severe in many regions worldwide. Vitis vinifera cultivars are highly susceptible to freeze injury, providing the wounds necessary for infection by A. Vitis. Wound position in relation to the uppermost bud of cuttings was determined to be important in tumor development. Inoculated wounds below buds developed tumors, whereas wounds opposite the bud did not, implying that indole-3-aectic acid flow contributes to tumor formation. If auxin was applied to wounds prior to inoculation with a tumorigenic A. Vitis strain, all sites of inoculation developed tumors, accompanied by an increased amount of callus in the cambium. Wounds inoculated with an A. Vitis biological control strain F2/5 prior to application of the pathogen did not develop galls. A closer examination of these wounds determined that callus cells formed in the cambium during wound healing are susceptible to transformation by the pathogen. Although the ...
Leon Otten - One of the best experts on this subject based on the ideXlab platform.
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Tartrate utilization genes promote growth of Agrobacterium spp. on grapevine
Molecular Plant-Microbe Interactions®, 1998Co-Authors: J. Y. Salomone, Erno Szegedi, P. Cobanov, Leon OttenAbstract: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.
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Major differences between the rrnA operons of two strains of Agrobacterium Vitis.
Archives of microbiology, 1996Co-Authors: Leon Otten, P. De RuffrayAbstract: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.
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Characterization and distribution of tartrate utilization genes in the grapevine pathogen Agrobacterium Vitis.
Molecular Plant-microbe Interactions, 1996Co-Authors: J. Y. Salomone, P. Crouzet, De Ruffray P, Leon OttenAbstract: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.
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Further evidence that the vitopine-type pTi's of Agrobacterium Vitis represent a novel group of Ti plasmids
Molecular Plant-Microbe Interactions, 1996Co-Authors: Erno Szegedi, Mihály Czakó, Leon OttenAbstract:To study the incompatibility properties of the vitopine Ti plasmids of Agrobacterium Vitis, pPM739 containing the cloned ori region of pTiS4 was introduced by triparental mating into seven Agrobacterium tumefaciens strains carrying incRh-1, incRh-2, and incAg-1 plasmids and into eight A. Vitis strains. All strains containing pPM739 retained their original plasmids and virulence or the ability to grow on tartrate, except for the three vitopine strains S4, Sz1, and NW11. Furthermore, pTiS4 was stably maintained in S4 cells following introduction of the ori/inc clones of the incRh-1, incRh-2, and incRh-3 plasmids. These results show that vitopine Ti plasmids represent a novel incompatibility group for which we propose the name incRh-4.
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Sequence and mutational analysis of a tartrate utilization operon from Agrobacterium Vitis.
Journal of bacteriology, 1995Co-Authors: P. Crouzet, Leon OttenAbstract:The grapevine is the natural host of the tumorigenic bacterium Agrobacterium Vitis. Most of the A. Vitis isolates can use tartrate, an unusually abundant compound in grapevine. The nopaline strain, AB4, contains a 170-kb conjugative plasmid (pTrAB4) encoding tartrate utilization. A 5.65-kb pTrAB4 region which enables non-tartrate-utilizing Agrobacterium tumefaciens to grow on tartrate was sequenced and mutagenized with the transcriptional fusion transposon Tn5-uidA1. This DNA fragment contains four intact open reading frames (ORFs) (ttuABCD) required for tartrate-dependent growth. The mutant phenotypes of each ORF, their homologies to published sequences, and their induction patterns allowed us to propose a model for tartrate utilization in A. Vitis. ttuA encodes a LysR-like transcriptional activator and is transcribed in the absence of tartrate. ttuB codes for a protein with homology to transporter proteins and is required for entry of tartrate into bacteria. ttuC codes for a tartrate dehydrogenase, while ttuD lacks homology to known sequences; the growth properties of ttuD mutants suggest that TtuD catalyzes the second step in tartrate degradation. A fifth incomplete ORF (ttuE) encodes a pyruvate kinase which is induced by tartrate and required for optimal growth. Although the ttuABCD fragment allows growth of A. tumefaciens on tartrate, it does not provide full tartrate utilization in the original A. Vitis background.
Desen Zheng - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of Grape Crown Gall by Agrobacterium Vitis F2/5 Requires Two Nonribosomal Peptide Synthetases and One Polyketide Synthase.
Molecular plant-microbe interactions : MPMI, 2016Co-Authors: Desen Zheng, Thomas J. BurrAbstract:Agrobacterium Vitis nontumorigenic strain F2/5 is able to inhibit crown gall disease on grapevines. The mechanism of grape tumor inhibition (GTI) by F2/5 has not been fully determined. In this study, we demonstrate that two nonribosomal peptide synthetase (NRPS) genes (F-avi3342 and F-avi5730) and one polyketide synthase gene (F-avi4330) are required for GTI. Knockout of any one of them resulted in F/25 losing GTI capacity. We previously reported that F-avi3342 and F-avi4330 but not F-avi5730 are required for induction of grape tissue necrosis and tobacco hypersensitive response. F-avi5730 is predicted to encode a single modular NRPS. It is located in a cluster that is homologous to the siderophore vicibactin biosynthesis locus in Rhizobium species. Individual disruption of F-avi5730 and two immediate downstream genes, F-avi5731 and F-avi5732, all resulted in reduced siderophore production; however, only F-avi5730 was found to be required for GTI. Complemented F-avi5730 mutant (ΔF-avi5730(+)) restored a wild-type level of GTI activity. It was determined that, over time, populations of ΔF-avi4330, ΔF-avi3342, and ΔF-avi5730 at inoculated wound sites on grapevine did not differ from those of ΔF-avi5730(+) indicating that loss of GTI was not due to reduced colonization of wound sites by mutants.
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inhibition of grape crown gall by Agrobacterium Vitis f2 5 requires two nonribosomal peptide synthetases and one polyketide synthase
Molecular Plant-microbe Interactions, 2016Co-Authors: Desen Zheng, Thomas J. BurrAbstract:Agrobacterium Vitis nontumorigenic strain F2/5 is able to inhibit crown gall disease on grapevines. The mechanism of grape tumor inhibition (GTI) by F2/5 has not been fully determined. In this study, we demonstrate that two nonribosomal peptide synthetase (NRPS) genes (F-avi3342 and F-avi5730) and one polyketide synthase gene (F-avi4330) are required for GTI. Knockout of any one of them resulted in F/25 losing GTI capacity. We previously reported that F-avi3342 and F-avi4330 but not F-avi5730 are required for induction of grape tissue necrosis and tobacco hypersensitive response. F-avi5730 is predicted to encode a single modular NRPS. It is located in a cluster that is homologous to the siderophore vicibactin biosynthesis locus in Rhizobium species. Individual disruption of F-avi5730 and two immediate downstream genes, F-avi5731 and F-avi5732, all resulted in reduced siderophore production; however, only F-avi5730 was found to be required for GTI. Complemented F-avi5730 mutant (ΔF-avi5730(+)) restored a wild-type level of GTI activity. It was determined that, over time, populations of ΔF-avi4330, ΔF-avi3342, and ΔF-avi5730 at inoculated wound sites on grapevine did not differ from those of ΔF-avi5730(+) indicating that loss of GTI was not due to reduced colonization of wound sites by mutants.
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a host specific biological control of grape crown gall by Agrobacterium Vitis strain f2 5 its regulation and population dynamics
Phytopathology, 2013Co-Authors: Supaporn Kaewnum, Desen Zheng, C. L. Reid, Kameka L Johnson, Jodi C Gee, Thomas J. BurrAbstract:Nontumorigenic Agrobacterium Vitis strain F2/5 is able to prevent crown gall caused by tumorigenic A. Vitis on grape but not on other plant species such as tobacco. Mutations in a quorum-sensing transcription factor, aviR, and in caseinolytic protease (clp) component genes clpA and clpP1 resulted in reduced or loss of biological control. All mutants were complemented; however, restoration of biological control by complemented clpA and clpP1 mutants was dependent on the copy number of vector that was used as well as timing of application of the complemented mutants to grape wounds in relation to inoculation with pathogen. Mutations in other quorum-sensing and clp genes and in a gene associated with polyketide synthesis did not affect biological control. It was determined that, although F2/5 inhibits transformation by tumorigenic A. Vitis strains on grape, it does not affect growth of the pathogen in wounded grape tissue over time.
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Development of a Magnetic Capture Hybridization Real-Time PCR Assay for Detection of Tumorigenic Agrobacterium Vitis in Grapevines
Phytopathology, 2013Co-Authors: Kameka L Johnson, Desen Zheng, C. L. Reid, Supaporn Kaewnum, Thomas J. BurrAbstract:Johnson, K. L., Zheng, D., Kaewnum, S., Reid, C. L., and Burr, T. 2013. Development of a magnetic capture hybridization real-time PCR assay for detection of tumorigenic Agrobacterium Vitis in grapevines. Phytopathology 103:633-640. Agrobacterium Vitis, the causal agent of grape crown gall, can have severe economic effects on grape production. The bacterium survives systemically in vines and, therefore, is disseminated in propagation material. We developed an assay for use in indexing programs that is efficient and sensitive for detecting A. Vitis in grape tissue. Initially, realtime polymerase chain reaction (PCR) primers specific for diverse tumorigenic strains of A. Vitis were developed using the virD2 gene sequence. To overcome the effects of PCR inhibitors present in plant tissue, DNA extraction methods that included magnetic capture hybridization (MCH), immunomagnetic separation (IMS), and extraction with the Mo Bio Powerfood kit were compared. The assays incorporating MCH or IMS followed by real-time PCR were 10,000-fold more sensitive than direct real-time PCR when tested using boiled bacterial cell suspensions, with detection thresholds of 10 1 CFU/ml compared with 10 5 CFU/ml. DNA extraction with the Powerfood DNA extraction kit was 10fold more sensitive than direct real-time PCR, with a detection threshold of 10 4 CFU/ml. All three assays were able to detect A. Vitis in healthyappearing grapevine cuttings taken from infected vines.
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A host-specific biological control of grape crown gall by Agrobacterium Vitis strain F2/5: its regulation and population dynamics.
Phytopathology, 2013Co-Authors: Supaporn Kaewnum, Desen Zheng, C. L. Reid, Kameka L Johnson, Jodi C Gee, Thomas J. BurrAbstract:Nontumorigenic Agrobacterium Vitis strain F2/5 is able to prevent crown gall caused by tumorigenic A. Vitis on grape but not on other plant species such as tobacco. Mutations in a quorum-sensing transcription factor, aviR, and in caseinolytic protease (clp) component genes clpA and clpP1 resulted in reduced or loss of biological control. All mutants were complemented; however, restoration of biological control by complemented clpA and clpP1 mutants was dependent on the copy number of vector that was used as well as timing of application of the complemented mutants to grape wounds in relation to inoculation with pathogen. Mutations in other quorum-sensing and clp genes and in a gene associated with polyketide synthesis did not affect biological control. It was determined that, although F2/5 inhibits transformation by tumorigenic A. Vitis strains on grape, it does not affect growth of the pathogen in wounded grape tissue over time.
C. L. Reid - One of the best experts on this subject based on the ideXlab platform.
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Identifying Environmental Sources of Agrobacterium Vitis in Vineyards and Wild Grapevines
American Journal of Enology and Viticulture, 2017Co-Authors: Didem Canik Orel, C. L. Reid, Marc Fuchs, Thomas J. BurrAbstract: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.
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Distribution of Agrobacterium Vitis in Grapevines and Its Relevance to Pathogen Elimination.
Plant disease, 2016Co-Authors: Kameka L Johnson, C. L. Reid, Heather Cronin, Thomas J. BurrAbstract:Agrobacterium Vitis, the cause of crown gall disease on grapevine, survives internally in vines and can be spread in cuttings for propagation. The possibility of generating pathogen-free vines through tissue culture makes it essential to understand the distribution of the pathogen in grapevines. A highly sensitive magnetic capture hybridization procedure along with real-time polymerase chain reaction were used to measure the distribution of tumorigenic A. Vitis in dormant canes and green shoots of grapevines. Tumorigenic A. Vitis was distributed from the basal to apical nodal and internodal tissues of canes as well as in nonlignified green shoots. In experiments conducted in 2013, A. Vitis was detected in up to 17% of shoot tips and 52% of meristems of greenhouse-grown plants initiated from known A. Vitis-contaminated cuttings. A lower frequency of detection was observed from surface-disinfected shoot tips (7%) as compared with nondisinfected tips (37%), suggesting epiphytic survival on green tissues. In ...
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a host specific biological control of grape crown gall by Agrobacterium Vitis strain f2 5 its regulation and population dynamics
Phytopathology, 2013Co-Authors: Supaporn Kaewnum, Desen Zheng, C. L. Reid, Kameka L Johnson, Jodi C Gee, Thomas J. BurrAbstract:Nontumorigenic Agrobacterium Vitis strain F2/5 is able to prevent crown gall caused by tumorigenic A. Vitis on grape but not on other plant species such as tobacco. Mutations in a quorum-sensing transcription factor, aviR, and in caseinolytic protease (clp) component genes clpA and clpP1 resulted in reduced or loss of biological control. All mutants were complemented; however, restoration of biological control by complemented clpA and clpP1 mutants was dependent on the copy number of vector that was used as well as timing of application of the complemented mutants to grape wounds in relation to inoculation with pathogen. Mutations in other quorum-sensing and clp genes and in a gene associated with polyketide synthesis did not affect biological control. It was determined that, although F2/5 inhibits transformation by tumorigenic A. Vitis strains on grape, it does not affect growth of the pathogen in wounded grape tissue over time.
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Development of a Magnetic Capture Hybridization Real-Time PCR Assay for Detection of Tumorigenic Agrobacterium Vitis in Grapevines
Phytopathology, 2013Co-Authors: Kameka L Johnson, Desen Zheng, C. L. Reid, Supaporn Kaewnum, Thomas J. BurrAbstract:Johnson, K. L., Zheng, D., Kaewnum, S., Reid, C. L., and Burr, T. 2013. Development of a magnetic capture hybridization real-time PCR assay for detection of tumorigenic Agrobacterium Vitis in grapevines. Phytopathology 103:633-640. Agrobacterium Vitis, the causal agent of grape crown gall, can have severe economic effects on grape production. The bacterium survives systemically in vines and, therefore, is disseminated in propagation material. We developed an assay for use in indexing programs that is efficient and sensitive for detecting A. Vitis in grape tissue. Initially, realtime polymerase chain reaction (PCR) primers specific for diverse tumorigenic strains of A. Vitis were developed using the virD2 gene sequence. To overcome the effects of PCR inhibitors present in plant tissue, DNA extraction methods that included magnetic capture hybridization (MCH), immunomagnetic separation (IMS), and extraction with the Mo Bio Powerfood kit were compared. The assays incorporating MCH or IMS followed by real-time PCR were 10,000-fold more sensitive than direct real-time PCR when tested using boiled bacterial cell suspensions, with detection thresholds of 10 1 CFU/ml compared with 10 5 CFU/ml. DNA extraction with the Powerfood DNA extraction kit was 10fold more sensitive than direct real-time PCR, with a detection threshold of 10 4 CFU/ml. All three assays were able to detect A. Vitis in healthyappearing grapevine cuttings taken from infected vines.
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A host-specific biological control of grape crown gall by Agrobacterium Vitis strain F2/5: its regulation and population dynamics.
Phytopathology, 2013Co-Authors: Supaporn Kaewnum, Desen Zheng, C. L. Reid, Kameka L Johnson, Jodi C Gee, Thomas J. BurrAbstract:Nontumorigenic Agrobacterium Vitis strain F2/5 is able to prevent crown gall caused by tumorigenic A. Vitis on grape but not on other plant species such as tobacco. Mutations in a quorum-sensing transcription factor, aviR, and in caseinolytic protease (clp) component genes clpA and clpP1 resulted in reduced or loss of biological control. All mutants were complemented; however, restoration of biological control by complemented clpA and clpP1 mutants was dependent on the copy number of vector that was used as well as timing of application of the complemented mutants to grape wounds in relation to inoculation with pathogen. Mutations in other quorum-sensing and clp genes and in a gene associated with polyketide synthesis did not affect biological control. It was determined that, although F2/5 inhibits transformation by tumorigenic A. Vitis strains on grape, it does not affect growth of the pathogen in wounded grape tissue over time.
