Analysis of Gene-for-Gene Interactions Between Pseudomonas syringae. pv. phaseolicola and Phaseolus.

Mansfıeld, John W.; Tsiamis, George; Puri, Nakul; Bennett, Mark A.; Jenner, Carol E.; Stevens, Conrad; Teverson, D.; Lyons, N. F.; Taylor, John D.

doi:10.1007/978-94-011-5472-7_70

Cited by 7 publications

(9 citation statements)

References 17 publications

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“…The resistance responses activated by different avr‐R gene combinations may all be classified as the HR, but they may be phenotypically different because of, for example, differential timing of plant cell collapse. Differences are clear in bean as the avrPphB‐R3 interaction provokes a more rapid HR than avrPphE‐R2 (Mansfield et al ., 1994, 1997a,b). In many race‐cultivar interactions, several different α avr genes and their matching R genes may be present in the pathogen and plant, respectively (Mansfield et al ., 1997a).…”

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confidence: 99%

Cultivar-specific avirulence and virulence functions assigned to avrPphF in Pseudomonas syringae pv. phaseolicola, the cause of bean halo-blight disease

et al. 2000

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The avrPphF gene was cloned from Pseudomonas syringae pathovar phaseolicola (Pph) races 5 and 7, based on its ability to confer avirulence towards bean cultivars carrying the R1 gene for halo-blight resistance, such as Red Mexican. avrPphF comprised two open reading frames, which were both required for function, and was located on a 154 kb plasmid (pAV511) in Pph. Strain RW60 of Pph, lacking pAV511, displayed a loss in virulence to a range of previously susceptible cultivars such as Tendergreen and Canadian Wonder. In Tendergreen virulence was restored to RW60 by avrPphF alone, whereas subcloned avrPphF in the absence of pAV511 greatly accelerated the hypersensitive resistance reaction caused by RW60 in Canadian Wonder. A second gene from pAV511, avrPphC, which controls avirulence to soybean, was found to block the activity of avrPphF in Canadian Wonder, but not in Red Mexican. avrPphF also conferred virulence in soybean. The multiple functions of avrPphF illustrate how effector proteins from plant pathogens have evolved to be recognized by R gene products and, therefore, be classi®ed as encoded by avirulence genes.

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Section: Introductionmentioning

confidence: 99%

Cultivar-specific avirulence and virulence functions assigned to avrPphF in Pseudomonas syringae pv. phaseolicola, the cause of bean halo-blight disease

et al. 2000

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“…Halo blight disease of bean ( Phaseolus vulgaris ) caused by Pseudomonas syringae pv. phaseolicola (hereafter Psph ) involves the interaction between five R genes and five avr genes (Taylor et al ., 1996; Mansfield et al ., 1997b). The avr genes matching R1 , R2 and R3 have been cloned and sequenced.…”

Section: Introductionmentioning

confidence: 99%

“…The avr genes matching R1, R2 and R3 have been cloned and sequenced. Their full designations are avrPphF.R1, avrPphE.R2 and avrPphB.R3 ; the terminal R gene designation will not be used further in this article (Jenner et al, 1991;Vivian and Mansfield, 1993;Mansfield et al, 1994Mansfield et al, , 1997b. The avrPphF and avrPphB genes are not present in races of Psph that are virulent on cultivars possessing R1 or R3 respectively.…”

Section: Introductionmentioning

confidence: 99%

Sequence variations in alleles of the avirulence gene avrPphE.R2 from Pseudomonas syringae pv. phaseolicola lead to loss of recognition of the AvrPphE protein within bean cells and a gain in cultivar‐specific virulence

Stevens

Bennett

Athanassopoulos

et al. 1998

Molecular Microbiology

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SummaryThe bean halo blight pathogen, Pseudomonas syringae pv. phaseolicola (Psph), is differentiated into nine races based on the presence or absence of five avirulence (avr ) genes in the bacterium, which interact with corresponding resistance genes, R1-R5, in Phaseolus vulgaris. The resistance gene R2 is matched by avrPphE, which is located adjacent to the cluster of hrp genes that are required for pathogenicity of Psph. Although only races 2, 4, 5 and 7 are avirulent on cultivars with R2 (inducing the hypersensitive response; HR), homologues of avrPphE are present in all races of Psph. DNA sequencing of avrPphE alleles from races of Psph has demonstrated two routes to virulence: via single basepair changes conferring amino acid substitutions in races 1, 3, 6 and 9 and an insertion of 104 bp in the allele in race 8. We have demonstrated that these base changes are responsible for the difference between virulence and avirulence by generating transconjugants of a virulent race harbouring plasmids expressing the various alleles of avrPphE. Agrobacterium tumefaciens-directed expression of avrPphE from race 4 in bean leaves induced the HR in a resistance gene-specific manner, suggesting that the AvrPphE protein is alone required for HR induction and is recognized within the plant cell. The allele from race 6, which is inactive if expressed in Psph, elicited a weak HR if expressed in planta, whereas the allele from race 1 did not. Our results suggest that the affinity of interaction between AvrPphE homologues and an unknown plant receptor mediates the severity of the plant's response. Mutation of avrPphE alleles did not affect the ability to colonize bean from a low level of inoculum. The avirulence gene avrPphB, which matches the R3 resistance gene, also caused a gene-specific HR following expression in the plant after delivery by A. tumefaciens.

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“…The avr genes matching R1, R2, and R3 have been cloned and sequenced. Their full designations are avrPphF.R1, avrPphE.R2, and avrPphB.R3; the terminal R gene designation will not be used here (3)(4)(5). Both avrPphE and avrPphB are chromosomal, whereas avrPphF is located on a large plasmid in those races that cause the hypersensitive reaction (HR) in cultivars of bean with the matching R1 gene.…”

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Identification of a pathogenicity island, which contains genes for virulence and avirulence, on a large native plasmid in the bean pathogenPseudomonas syringaepathovar phaseolicola

Jackson

Athanassopoulos

Tsiamis

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

300

253

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The 154-kb plasmid was cured from race 7 strain 1449B of the phytopathogen Pseudomonas syringae pv. phaseolicola (Pph). Cured strains lost virulence toward bean, causing the hypersensitive reaction in previously susceptible cultivars. Restoration of virulence was achieved by complementation with cosmid clones spanning a 30-kb region of the plasmid that contained previously identified avirulence (avr) genes avrD, avrPphC, and avrPphF. Single transposon insertions at multiple sites (including one located in avrPphF) abolished restoration of virulence by genomic clones. Sequencing 11 kb of the complementing region identified three potential virulence (vir) genes that were predicted to encode hydrophilic proteins and shared the hrp-box promoter motif indicating regulation by HrpL. One gene achieved partial restoration of virulence when cloned on its own and therefore was designated virPphA as the first (A) gene from Pph to be identified for virulence function. In soybean, virPphA acted as an avr gene controlling expression of a rapid cultivar-specific hypersensitive reaction. Sequencing also revealed the presence of homologs of the insertion sequence IS100 from Yersinia and transposase Tn501 from P. aeruginosa. The proximity of several avr and vir genes together with mobile elements, as well as G؉C content significantly lower than that expected for P. syringae, indicates that we have located a plasmidborne pathogenicity island equivalent to those found in mammalian pathogens.Varietal resistance to halo-blight disease of bean (Phaseolus vulgaris L.) caused by Pseudomonas syringae pv. phaseolicola (Pph) is determined by gene-for-gene interactions involving five resistance (R) genes in the host and five matching avirulence (avr) genes in the pathogen. Depending on the presence or absence of functional avr genes, nine races of Pph have been distinguished (1, 2). The avr genes matching R1, R2, and R3 have been cloned and sequenced. Their full designations are avrPphF.R1, avrPphE.R2, and avrPphB.R3; the terminal R gene designation will not be used here (3-5). Both avrPphE and avrPphB are chromosomal, whereas avrPphF is located on a large plasmid in those races that cause the hypersensitive reaction (HR) in cultivars of bean with the matching R1 gene.

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Analysis of Gene-for-Gene Interactions Between Pseudomonas syringae. pv. phaseolicola and Phaseolus.

Cited by 7 publications

References 17 publications

Cultivar-specific avirulence and virulence functions assigned to avrPphF in Pseudomonas syringae pv. phaseolicola, the cause of bean halo-blight disease

Cultivar-specific avirulence and virulence functions assigned to avrPphF in Pseudomonas syringae pv. phaseolicola, the cause of bean halo-blight disease

Sequence variations in alleles of the avirulence gene avrPphE.R2 from Pseudomonas syringae pv. phaseolicola lead to loss of recognition of the AvrPphE protein within bean cells and a gain in cultivar‐specific virulence

Identification of a pathogenicity island, which contains genes for virulence and avirulence, on a large native plasmid in the bean pathogenPseudomonas syringaepathovar phaseolicola

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