Plasmids and Phaseolotoxin Production in Pseudomonas syringae pv. phaseolicola

Jamieson, A. F.; Bieleski, R. L.; Mitchell, Robin E.

doi:10.1099/00221287-122-1-161

Cited by 4 publications

(4 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous reports regarding the possible involvement of plasmids in phaseolotoxin production have been contradictory (7,12,21). The 32P-labeled 8.3-kb EcoRI fragment cloned from strain NPS4336 showed no homology in Southern blot analysis to detectable indigenous plasmids from strain NPS3121 (data not shown).…”

Section: Resultsmentioning

confidence: 99%

“…Several plasmids have been detected and partially characterized in P. syringae pv. "phaseolicola" (2,7,12,21,27,36,37). Except for one report (7), no positive evidence for the involvement of plasmids in phaseolotoxin production has been obtained (12,21).…”

mentioning

confidence: 99%

“…"phaseolicola" (2,7,12,21,27,36,37). Except for one report (7), no positive evidence for the involvement of plasmids in phaseolotoxin production has been obtained (12,21).The production of phaseolotoxin by P. syringae pv. "phaseolicola" is temperature regulated.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Identification and cloning of genes involved in phaseolotoxin production by Pseudomonas syringae pv. "phaseolicola"

Peet¹,

Lindgren²,

Willis³

et al. 1986

J Bacteriol

View full text Add to dashboard Cite

Genes involved in the production of phaseolotoxin by Pseudomonas syringae pv. "phaseolicola" NPS3121 were identified by TnS mutagenesis and cosmid cloning. A total of 5,180 kanamycin-resistant colonies were screened for the loss of phaseolotoxin production by a microbiological assay. Six independent, prototrophic, Tox-mutants were isolated that had TnS insertions in five different EcoRI fragments. All six mutants had TnS inserted in the same KpnI fragment, which had a length of ca. 28 kilobases including TnS. The mutants produced residual toxin in vitro. An EcoRI fragment containing TnS and flanking sequences from mutant NPS4336 was cloned and used to probe a wild-type genomic library by colony hybridization. Seven recombinant plasmids showing homology to this probe were identified. Each Tox-mutant was restored in OCTase-specific toxin production by two or more of the recombinant plasmids. The data suggest that at least some of the genes involved in phaseolotoxin production were clustered in a large KpnI fragment. No homology was detected between the Tn5 target fragment cloned from mutant NPS4336 and the total genomic DNA from closely or distantly related bacteria that do not produce phaseolotoxin.Pseudomonas syringae pv. "phaseolicola," the causal agent of the halo blight of beans, produces a chlorosisinducing toxin, phaseolotoxin. Phaseolotoxin production is responsible for the local and systemic chlorotic symptoms associated with the disease. Naturally occurring Toxstrains (9) or Tox-mutants of P. syringae pv. "phaseolicola" obtained after treatment with nitrosoguanidine (33) or UV light (23) or by other means (30) have been described previously. These mutants produce typical water-soaked lesions but do not cause chlorosis (9,23,30,33) or spread systemically in the plant (23). Phaseolotoxin inhibits the enzyme ornithine carbamoyltransferase (OCTase) from a variety of organisms (4,24,25,33). The toxin causes ornithine to accumulate in infected bean leaves (4,22,28,29 hibitory to E. coli, they are considerably less potent than are equimolar quantities of phaseolotoxin. This may reflect differences in the kinetics of their uptake or other factors and results in different dose-response curves for these inhibitors (19).The involvement of plasmids in toxin production by plant pathogenic bacteria including P. syringae pv. "phaseolicola" has been extensively investigated. Genes involved in the production of the toxin coronatine by P. syringae pv. "glycinea" (J. W. Willis and J. V. Leary, Phytopathology 74:838, abstr. no. 387, 1984) and P. syringae pv. "atropurpurea" (31) appear to be plasmid encoded. By contrast, genes involved in the production of the toxin syringomycin by P. syringae pv. "syringae" do not appear to be plasmid associated (8). Several plasmids have been detected and partially characterized in P. syringae pv. "phaseolicola" (2,7,12,21,27,36,37). Except for one report (7), no positive evidence for the involvement of plasmids in phaseolotoxin production has been obtained (12,21).The production of phas...

show abstract

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Identification and cloning of genes involved in phaseolotoxin production by Pseudomonas syringae pv. "phaseolicola"

Peet¹,

Lindgren²,

Willis³

et al. 1986

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…Phaseolotoxin and syringomycin are two P. syringae phytotoxins for which plasmid DNA has been implicated in toxin biosynthesis (7,10). However, attempts to unequivocally associate plasmid DNA with the production of phaseolotoxin and syringomycin have been unsuccessful (6,9,12). Moreover, several researchers, using transposon mutagenesis, have found chromosomal rather than plasmid locations for phaseolotoxin and syringotoxin genes (22,25,26).…”

Section: Discussionmentioning

confidence: 99%

Plasmid-mediated production of the phytotoxin coronatine by Pseudomonas syringae pv. tomato

1989

Toxicon

View full text Add to dashboard Cite

Pseudomonas syringae pv. tomato PT23.2 produces the chlorosis-inducing phytotoxin coronatine. Thirtyeight chlorosis-defective mutants of PT23.2 were previously generated by using the transposon TnS. Five mutants contained Tn5 insertions in the indigenous plasmid pPT23A; the remaining 33 mutants either were missing pPT23A (29 mutants) or contained deletions in this plasmid (4 mutants). These results suggested that pPT23A was involved in coronatine production in strain PT23.2. This plasmid was introduced into P. syringae pv. syringae PS61, which does not produce coronatine. A bioassay for coronatine suggested that PS61(pPT23A) transconjugants were able to make this phytotoxin. In a chemical analysis, organic acids were isolated from PT23.2, PS61, and the transconjugant PS61(pPT23A); these were derivatized to their methyl esters and analyzed by gas chromatography. The derivatized organic acids extracted from PT23.2 and PS61(pPT23A) contained peaks that corresponded to coronafacic acid, coronafacoylvaline, and coronatine, but these were absent in the extracts from the wild-type strain PS61. The identification of these components was confirmed by combined gas chromatography-mass spectrophotometry. Therefore, the acquisition of pPT23A by PS61 resulted in biosynthesis of coronafacic acid, coronafacoylvaline, and coronatine, clearly demonstrating the involvement of pPT23A in coronatine production in P. syringae pv. tomato.The chlorosis-inducing phytotoxin coronatine has a unique structure (Fig. 1), consisting of a polyketide component (coronafacic acid) joined to a cyclopropane structure derived from isoleucine (11,19,24). Coronatine is produced by several Pseudomonas syringae pathovars, including P. syringae pv. atropurpurea (23), P. syringae pv. glycinea (21), P. syringae pv. tomato (3, 20), and P. syringae pv. morsprunorum (17), which are pathogens of ryegrass, soybean, tomato, and Prunus spp., respectively. Coronatine production by multiple pathovars of P. syringae contrasts with production of the phytotoxins phaseolotoxin and syringomycin, which is thought to be restricted to P. syringae pv. phaseolicola and P. syringae pv. syringae, respectively. In addition to chlorosis, coronatine induces stunting (8) and hypertrophy (28) of plant tissue. Recently, Bender et al. (3) reported that coronatine synthesis is important in the virulence of P. syringae pv. tomato and contributes significantly to both lesion expansion and multiplication of the bacterium in tomato leaves. The unusual structure and biosynthetic origin of coronatine and its importance in the symptomology of several P. syringae pathovars have prompted us to study the genetics of its production.In a previous study (3), 1,000 Tn5 mutants of strain PT23.2 were generated and screened for their ability to induce chlorosis in planta. Ten chlorosis-defective, nontoxigenic (Tox-) mutants were recovered; nine mutants were further analyzed and found to be defective in production of coronatine (3; R. E. Mitchell, personal communication). In the present study, the phy...

show abstract

The Evolution of Pathogenesis and Race Specificity

Mills¹,

Gonzalez²

1982

Phytopathogenic Prokaryotes

View full text Add to dashboard Cite

Plasmids and Phaseolotoxin Production in Pseudomonas syringae pv. phaseolicola

Cited by 4 publications

References 5 publications

Identification and cloning of genes involved in phaseolotoxin production by Pseudomonas syringae pv. "phaseolicola"

Identification and cloning of genes involved in phaseolotoxin production by Pseudomonas syringae pv. "phaseolicola"

Plasmid-mediated production of the phytotoxin coronatine by Pseudomonas syringae pv. tomato

The Evolution of Pathogenesis and Race Specificity

Contact Info

Product

Resources

About