Effect of N-phenyl-2-naphtylamine on cAMP level and virulence factors of Pseudomonas syringae pv. pisi and Clavibacter michiganensis ssp. sepedonicus

2017 ◽  
Vol 2017 (1) ◽  
pp. 100-105
Author(s):  
L. A. Lomovatskaya ◽  
◽  
L. E. Makarova ◽  
O. V. Kuzakova ◽  
A. M. Goncharova ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Virulence Factors ◽  
Camp Level ◽  
Clavibacter Michiganensis

scholarly journals Effect of Iron Concentration on the Growth Rate of Pseudomonas syringae and the Expression of Virulence Factors in hrp-Inducing Minimal Medium

2009 ◽  
Vol 75 (9) ◽  
pp. 2720-2726 ◽  
Author(s):  
Beum Jun Kim ◽  
Joon Ho Park ◽  
Tai Hyun Park ◽  
Philip A. Bronstein ◽  
David J. Schneider ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Virulence Factors ◽  
Minimal Medium ◽  
Iron Concentration ◽  
Medium Components ◽  
Iron Oxalate ◽  
Limiting Nutrient ◽  
Essential Nutrient ◽  
Virulence Factor Gene ◽  
Kinetics Of

ABSTRACT Although chemically defined media have been developed and widely used to study the expression of virulence factors in the model plant pathogen Pseudomonas syringae, it has been difficult to link specific medium components to the induction response. Using a chemostat system, we found that iron is the limiting nutrient for growth in the standard hrp-inducing minimal medium and plays an important role in inducing several virulence-related genes in Pseudomonas syringae pv. tomato DC3000. With various concentrations of iron oxalate, growth was found to follow Monod-type kinetics for low to moderate iron concentrations. Observable toxicity due to iron began at 400 μM Fe3+. The kinetics of virulence factor gene induction can be expressed mathematically in terms of supplemented-iron concentration. We conclude that studies of induction of virulence-related genes in P. syringae should control iron levels carefully to reduce variations in the availability of this essential nutrient.

scholarly journals The Pseudomonas syringae avrRpt2 Gene Contributes to Virulence on Tomato

2005 ◽  
Vol 18 (7) ◽  
pp. 626-633 ◽  
Author(s):  
Melisa T. S. Lim ◽  
Barbara N. Kunkel
Keyword(s):  
Pseudomonas Syringae ◽  
Virulence Factors ◽  
Host Defense ◽  
Virulence Gene ◽  
Bacterial Virulence ◽  
Host Tissue ◽  
Native Strain ◽  
Phytopathogenic Bacteria ◽  
Gram Negative ◽  
Mutant Derivative

In order to cause disease on plants, gram-negative phytopathogenic bacteria introduce numerous virulence factors into the host cell in order to render host tissue more hospitable for pathogen proliferation. The mode of action of such bacterial virulence factors and their interaction with host defense pathways remain poorly understood. avrRpt2, a gene from Pseudomonas syringae pv. tomato JL1065, has been shown to promote the virulence of heterologous P. syringae strains on Arabidopsis thaliana. However, the contribution of avrRpt2 to the virulence of JL1065 has not been examined previously. We show that a mutant derivative of JL1065 that carries a disruption in avrRpt2 is impaired in its ability to cause disease on tomato (Lycopersicon esculentum), indicating that avrRpt2 also acts as a virulence gene in its native strain on a natural host. The virulence activity of avrRpt2 was detectable on tomato lines that are defective in either ethylene perception or the accumulation of salicylic acid, but could not be detected on a tomato mutant insensitive to jasmonic acid. The enhanced virulence conferred by the expression of avrRpt2 in JL1065 was not associated with the suppression of several defense-related genes induced during the infection of tomato.

scholarly journals Bakterijske i virusne bolesti rajčice i paprike u Hrvatskoj

2019 ◽  
Vol 42 (3) ◽  
pp. 36-42
Author(s):  
Dario Ivić
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Pseudomonas Syringae ◽  
Tomato Spotted Wilt Virus ◽  
Clavibacter Michiganensis ◽  
Tomato Spotted Wilt ◽  
Wilt Virus

U proteklih nekoliko godina u Hrvatskoj su zabilježene relativno visoke štete od pojedinih bakterijskih i virusnih bolesti u proizvodnji rajčice i paprike. Uzročnici tih bolesti bile su bakterije Pseudomonas syringae pv. tomato i Clavibacter michiganensis ssp. michiganensis te virusi Tomato spotted wilt virus (TSWV) i Cucumber mosaic virus (CMV). U članku su ukratko opisani spomenuti patogeni, njihovo širenje te mjere zaštite.

scholarly journals Comparative Genomics of Pathogenic Clavibacter michiganensis subsp. michiganensis Strains from Chile Reveals Potential Virulence Features for Tomato Plants

2020 ◽  
Vol 8 (11) ◽  
pp. 1679
Author(s):  
Valentina Méndez ◽  
Miryam Valenzuela ◽  
Francisco Salvà-Serra ◽  
Daniel Jaén-Luchoro ◽  
Ximena Besoain ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Phylogenetic Analyses ◽  
Plant Diseases ◽  
Genomic Diversity ◽  
Clavibacter Michiganensis ◽  
Tomato Plants ◽  
Clavibacter Michiganensis Subsp ◽  
Genomic Analyses ◽  
Encoding Genes ◽  
Genomic Similarity

The genus Clavibacter has been associated largely with plant diseases. The aims of this study were to characterize the genomes and the virulence factors of Chilean C. michiganensis subsp. michiganensis strains VL527, MSF322 and OP3, and to define their phylogenomic positions within the species, Clavibacter michiganensis. VL527 and MSF322 genomes possess 3,396,632 and 3,399,199 bp, respectively, with a pCM2-like plasmid in strain VL527, with pCM1- and pCM2-like plasmids in strain MSF322. OP3 genome is composed of a chromosome and three plasmids (including pCM1- and pCM2-like plasmids) of 3,466,104 bp. Genomic analyses confirmed the phylogenetic relationships of the Chilean strains among C.michiganensis subsp. michiganensis and showed their low genomic diversity. Different virulence levels in tomato plants were observable. Phylogenetic analyses of the virulence factors revealed that the pelA1 gene (chp/tomA region)—that grouped Chilean strains in three distinct clusters—and proteases and hydrolases encoding genes, exclusive for each of the Chilean strains, may be involved in these observed virulence levels. Based on genomic similarity (ANIm) analyses, a proposal to combine and reclassify C. michiganensis subsp. phaseoli and subsp. chilensis at the species level, as C. phaseoli sp. nov., as well as to reclassify C. michiganensis subsp. californiensis as the species C. californiensis sp. nov. may be justified.

scholarly journals Comparative Dynamics of Adherent and Nonadherent Bacterial Populations on Maize Leaves

2002 ◽  
Vol 92 (9) ◽  
pp. 1015-1023 ◽  
Author(s):  
Gwyn A. Beattie ◽  
Lise M. Marcell
Keyword(s):  
Pseudomonas Syringae ◽  
Bacterial Species ◽  
Bacterial Adherence ◽  
Cuticular Wax ◽  
Adherent Cells ◽  
Clavibacter Michiganensis ◽  
Bacterial Populations ◽  
Clavibacter Michiganensis Subsp ◽  
Maize Leaves ◽  
Survival And Growth

The dynamics of the adherent and nonadherent populations of three bacterial species on maize leaves were examined to identify the extent to which bacteria adhere to leaves and the importance of this adhesion to leaf colonization. Pantoea agglomerans strain BRT98, Clavibacter michiganensis subsp. nebraskensis strain GH2390, and Pseudomonas syringae pv. syringae strain HS191R all rapidly adhered to maize leaves following inoculation, but differed in the percentage of cells that adhered to the leaves. Immediately following inoculation, the percentage of adherent cells was highest for the saprophyte P. agglomerans (8 to 10%) and was much lower for the pathogens C. michiganensis subsp. nebras-kensis and P. syringae pv. syringae (2 to 3 and <1%, respectively), although the results for P. syringae pv. syringae HS191R were based on only one experiment. In the 4 days following inoculation, the percentage of the P. agglomerans populations that adhered to the leaves increased to approximately 70%. Similarly, the percentage of C. michiganensis subsp. nebraskensis and P. syringae pv. syringae cells that resisted removal steadily increased in the days following inoculation, although these increases probably reflected both adherence and localization to endophytic sites. Based on differences in the percentage of cells adhering to several cuticular wax mutants of maize, the rapid adherence of C. michiganensis subsp. nebraskensis cells to maize leaves was influenced by the cuticular wax properties, while the rapid adherence of P. agglomerans was not. Finally, bacterial adherence to leaves was advantageous to P. agglomerans survival and growth on leaves based on the finding that the nonadherent populations of the P. agglomerans strain decreased significantly more than did the adherent populations in the 24 h following inoculation, and increased much less than did the adherent populations over the next 3 days. Similar results with the C. michiganensis subsp. nebraskensis and P. syringae pv. syringae strains indicate that bacterial adherence to leaves, bacterial movement to endophytic sites, or both were advantageous to the survival and growth of these strains on leaves.

scholarly journals Indole-3-Acetaldehyde Dehydrogenase-dependent Auxin Synthesis Contributes to Virulence ofPseudomonas syringaeStrain DC3000

2017 ◽  
Author(s):  
Sheri A. McClerklin ◽  
Soon Goo Lee ◽  
Ron Nwumeh ◽  
Joseph M. Jez ◽  
Barbara N. Kunkel
Keyword(s):  
Acetic Acid ◽  
Pseudomonas Syringae ◽  
Virulence Factors ◽  
Plant Hormone ◽  
Disease Development ◽  
Hormone Signaling ◽  
Host Defenses ◽  
Acetaldehyde Dehydrogenase ◽  
Indole 3 Acetic Acid

AbstractThe bacterial pathogenPseudomonas syringaemodulates plant hormone signaling to promote infection and disease development.P. syringaeuses several strategies to manipulate auxin physiology inArabidopsis thalianato promote pathogenesis, including synthesis of indole-3-acetic acid (IAA), the predominant form of auxin in plants, and production of virulence factors that alter auxin responses in the host; however, the role of pathogen-derived auxin inP. syringaepathogenesis is not well understood. Here we demonstrate thatP. syringaestrain DC3000 produces IAA via a previously uncharacterized pathway and identify a novel indole-3-acetaldehyde dehydrogenase, AldA, that functions in IAA biosynthesis by catalyzing the NAD-dependent formation of IAA from indole-3-acetaldehyde (IAAld). Biochemical analysis and solving of the 1.9 Å resolution x-ray crystal structure reveal key features of AldA for IAA synthesis, including the molecular basis of substrate specificity. Disruption ofaldAand a close homolog,aldB, lead to reduced IAA production in culture and reduced virulence onA. thaliana.We use these mutants to explore the mechanism by which pathogen-derived auxin contributes to virulence and show that IAA produced by DC3000 suppresses salicylic acid-mediated defenses inA. thaliana.Thus, auxin is a DC3000 virulence factor that promotes pathogenicity by suppressing host defenses.Author SummaryPathogens have evolved multiple strategies for suppressing host defenses and modulating host physiology to promote colonization and disease development. For example, the plant pathogenPseudomonas syringaeuses several strategies to the manipulate hormone signaling of its hosts, including production of virulence factors that alter hormone responses in and synthesis of plant hormones or hormone mimics. Synthesis of indole-3-acetic acid (IAA), a common form of the plant hormone auxin, by many plant pathogens has been implicated in virulence. However, the role of pathogen-derived IAA during pathogenesis by leaf spotting pathogens such asP. syringaestrain DC3000 is not well understood. Here, we demonstrate thatP. syringaestrain DC3000 uses a previously uncharacterized biochemical pathway to synthesize IAA, catalyzed by a novel aldehyde dehydrogenase, AldA, and carry out biochemical and structural studies of the AldA protein to investigate AldA activity and substrate specificity. We also generate analdAmutant disrupted in IAA synthesis to show that IAA is a DC3000 virulence factor that promotes pathogenesis by suppressing host defense responses.

scholarly journals EFEITO ANTIBIÓTICO DO PRÓPOLIS SOBRE BACTÉRIAS FITOPATOGÊNICAS

1998 ◽  
Vol 55 (1) ◽  
pp. 149-152 ◽  
Author(s):  
L. BIANCHINI ◽  
I.P. BEDENDO
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Pseudomonas Syringae ◽  
Erwinia Chrysanthemi ◽  
Clavibacter Michiganensis ◽  
Xanthomonas Axonopodis ◽  
Clavibacter Michiganensis Subsp

O efeito antibiótico de extrato aquoso de própolis, em várias concentrações, foi avaliado para cinco espécies de bactérias fitopatogênicas. Agrobacterium tumefaciens, Clavibacter michiganensis subsp. michiganensis e Xanthomonas axonopodis pv. phaseoli foram completamente inibidas em meio de cultura contendo 10% de extrato de própolis. Erwinia chrysanthemi foi parcialmente inibida, enquanto Pseudomonas syringae pv. tabaci se mostrou insensível ao extrato, desenvolvendo colônias idênticas àquelas observadas em meios livres de própolis. Concentrações menores não foram suficientes para exercer um efeito antimicrobiano desejável sobre as bactérias pertencentes a todas as espécies testadas. Resultados idênticos foram obtidos quando própolis foi incorporado ao meio antes ou após a autoclavagem, demonstrando que a substância ativa presente no extrato não é termosensível. Foi demonstrado, portanto, o uso potencial do própolis como antibiótico para o controle de bactérias fitopatogênicas.

scholarly journals The Erwinia chrysanthemi EC16 hrp/hrc Gene Cluster Encodes an Active Hrp Type III Secretion System That Is Flanked by Virulence Genes Functionally Unrelated to the Hrp System

2004 ◽  
Vol 17 (6) ◽  
pp. 644-653 ◽  
Author(s):  
Clemencia M. Rojas ◽  
Jong Hyun Ham ◽  
Lisa M. Schechter ◽  
Jihyun F. Kim ◽  
Steven V. Beer ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Pseudomonas Syringae ◽  
Virulence Factors ◽  
Type Iii Secretion ◽  
Type Iii Secretion System ◽  
Gene Clusters ◽  
Amino Acid Identity ◽  
Secretion System ◽  
Erwinia Chrysanthemi ◽  
Type Iii

Erwinia chrysanthemi is a host-promiscuous plant pathogen that possesses a type III secretion system (TTSS) similar to that of the host-specific pathogens E. amylovora and Pseudomonas syringae. The regions flanking the TTSS-encoding hrp/hrc gene clusters in the latter pathogens encode various TTSS-secreted proteins. DNA sequencing of the complete E. chrysanthemi hrp/hrc gene cluster and approximately 12 kb of the flanking regions (beyond the previously characterized hecA adhesin gene in the left flank) revealed that the E. chrysanthemi TTSS genes were syntenic and similar (>50% amino-acid identity) with their E. amylovora orthologs. However, the hrp/hrc cluster was interrupted by a cluster of four genes, only one of which, a homolog of lytic transglycosylases, is implicated in TTSS functions. Furthermore, the regions flanking the hrp/hrc cluster lacked genes that were likely to encode TTSS substrates. Instead, some of the genes in these regions predict ABC transporters and methyl-accepting chemotaxis proteins that could have alternative roles in virulence. Mutations affecting all of the genes in the regions flanking or interrupting the hrp/hrc cluster were constructed in E. chrysanthemi CUCPB5047, a mutant whose reduced pectolytic capacity can enhance the phenotype of minor virulence factors. Mutants were screened in witloof chicory leaves and then in potato tubers and Nicotiana clevelandii seedlings. Mu dII1734 insertion in one gene, designated virA, resulted in strongly reduced virulence in all three tests. virA is immediately downstream of hecA, has an unusually low G+C content of 38%, and predicts an unknown protein of 111 amino acids. The E. chrysanthemi TTSS was shown to be active by its ability to translocate AvrPto-Cya (a P. syringae TTSS effector fused to an adenylate cyclase reporter that is active in the presence of eukaryote calmodulin) into N. benthamiana However, VirA(1–61)¯ Cya was not translocated into plant cells, and virA expression was not affected by mutations in E. chrysanthemi Hrp regulator genes hrpL and hrpS. Thus, the 44-kb region of the E. chrysanthemi EC16 genome that is centered on the hrp/hrc cluster encodes a potpourri of virulence factors, but none of these appear to be a TTSS effector.

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