The hrp-Encoded Protein Export Systems of Pseudomonas syringae and Other Plant Pathogenic Bacteria and Their Role in Pathogenicity

1997 ◽  
pp. 145-179 ◽  
Author(s):  
Steven W. Hutcheson
Keyword(s):  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
Protein Export ◽  
Plant Pathogenic Bacteria

THE ACTIVITY OF ESSENTIAL OILS OBTAINED FROM SPECIES AND INTERSPECIES HYBRIDS OF THE Mentha GENUS AGAINST SELECTED PLANT PATHOGENIC BACTERIA

2018 ◽  
Vol 17 (6) ◽  
pp. 167-174 ◽  
Author(s):  
Małgorzata Schollenberger ◽  
Tomasz M. Staniek ◽  
Elżbieta Paduch-Cichal ◽  
Beata Dasiewicz ◽  
Agnieszka Gadomska-Gajadhur ◽  
...  
Keyword(s):  
Essential Oils ◽  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
Antimicrobial Effect ◽  
Mentha Piperita ◽  
Mentha Spicata ◽  
Plant Essential Oils ◽  
Plant Pathogenic Bacteria ◽  
Interspecies Hybrids

Plant essential oils of six aromatic herb species and interspecies hybrids of the family Lamiaceae – chocolate mint (Mentha piperita × ‘Chocolate’), pineapple mint (Mentha suaveolens ‘Variegata’), apple mint (Mentha × rotundifolia), spearmint (Mentha spicata), orange mint (Mentha × piperita ‘Granada’) and strawberry mint (Mentha × villosa ‘Strawberry’) – were investigated for antimicrobial effects against plant pathogenic bacteria: Agrobacterium tumefaciens, Pseudomonas syringae pv. syringae and Xanthomonas arboricola pv. corylina. The screening was carried out in vitro on agar plates filled with the target organism. All essential oils screened exhibited a higher level of antibacterial activity against A. tumefaciens and X. arboricola pv. corylina than streptomycin used as a standard in all tests. The antimicrobial effect of streptomycin and five mint oils was at the same level for P. syringae pv. syringae. There were no significant differences in the influence of the chocolate mint oil on the growth inhibition of all bacteria tested. Plant essential oils from pineapple mint, apple mint, spearmint and strawberry mint showed the weakest antimicrobial activity against P. syringae pv. syringae and the strongest towards A. tumefaciens and X. arboricola pv. corylina. The essential oils from strawberry mint, pineapple mint, spearmint and apple mint had the strongest effect on A. tumefaciens, and the lowest inhibitory activity was exhibited by the chocolate mint and orange mint essential oils. X. arboricola pv. corylina was the most sensitive to the strawberry mint, pineapple mint and spearmint oils. The chocolate mint oil showed the greatest activity against P. syringae pv. syringae.

scholarly journals Identification of Novel Type III Secretion Effectors in Xanthomonas oryzae pv. oryzae

2009 ◽  
Vol 22 (1) ◽  
pp. 96-106 ◽  
Author(s):  
Ayako Furutani ◽  
Minako Takaoka ◽  
Harumi Sanada ◽  
Yukari Noguchi ◽  
Takashi Oku ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Type Iii Secretion ◽  
Pathogenic Bacteria ◽  
Regulatory Protein ◽  
Effector Proteins ◽  
Xanthomonas Oryzae ◽  
Dependent Manner ◽  
Plant Pathogenic Bacteria ◽  
Type Iii ◽  
Genes Encoding

Many gram-negative bacteria secrete so-called effector proteins via a type III secretion (T3S) system. Through genome screening for genes encoding potential T3S effectors, 60 candidates were selected from rice pathogen Xanthomonas oryzae pv. oryzae MAFF311018 using these criteria: i) homologs of known T3S effectors in plant-pathogenic bacteria, ii) genes with expression regulated by hrp regulatory protein HrpX, or iii) proteins with N-terminal amino acid patterns associated with T3S substrates of Pseudomonas syringae. Of effector candidates tested with the Bordetella pertussis calmodulin-dependent adenylate cyclase reporter for translocation into plant cells, 16 proteins were translocated in a T3S system-dependent manner. Of these 16 proteins, nine were homologs of known effectors in other plant-pathogenic bacteria and seven were not. Most of the effectors were widely conserved in Xanthomonas spp.; however, some were specific to X. oryzae. Interestingly, all these effectors were expressed in an HrpX-dependent manner, suggesting coregulation of effectors and the T3S system. In X. campestris pv. vesicatoria, HpaB and HpaC (HpaP in X. oryzae pv. oryzae) have a central role in recruiting T3S substrates to the secretion apparatus. Secretion of all but one effector was reduced in both HpaB– and HpaP– mutant strains, indicating that HpaB and HpaP are widely involved in efficient secretion of the effectors.

scholarly journals The application of polymerase chain reaction for characterising strains of Pseudomonas syringae isolated from New Zealand rivers

2009 ◽  
Vol 62 ◽  
pp. 256-261 ◽  
Author(s):  
J.L. Vanneste ◽  
D.A. Cornish ◽  
J. Yu ◽  
C.E. Morris
Keyword(s):  
Polymerase Chain Reaction ◽  
New Zealand ◽  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
Chain Reaction ◽  
Plant Pathogenic Bacteria ◽  
Complex Group ◽  
Rivers And Lakes ◽  
Polymerase Chain ◽  
Waikato River

Pseudomonas syringae is a complex group of bacteria which comprises nine different genomospecies and over 50 pathovars Strains of P syringae have been isolated from some rivers and lakes in New Zealand To determine whether these waterways act as reservoirs of plant pathogenic bacteria 15 strains of P syringae isolated from the Waikato River and Whakapapanui stream have been further characterised using several polymerase chain reaction (PCR) protocols Five of those 15 strains belong to genomospecies 1 which comprises P syringae pv syringae but none belongs to genomospecies 2 The protocol for detection of P syringae pv papulans was modified and is now specific for this pathovar The identity of a strain isolated from the Waikato River as being P syringae pv atrofaciens has yet to be confirmed None of the 15 strains studied belongs to the pathovars papulans actinidiae tagetis helianthii or theae

scholarly journals AlgU Controls Expression of Virulence Genes in Pseudomonas syringae pv. tomato DC3000

2016 ◽  
Vol 198 (17) ◽  
pp. 2330-2344 ◽  
Author(s):  
Eric Markel ◽  
Paul Stodghill ◽  
Zhongmeng Bao ◽  
Christopher R. Myers ◽  
Bryan Swingle
Keyword(s):  
Oxidative Stress ◽  
Pseudomonas Syringae ◽  
Stress Responses ◽  
Sigma Factor ◽  
Pathogenic Bacteria ◽  
Promoter Sequence ◽  
Tomato Dc3000 ◽  
Content Type ◽  
Plant Pathogenic Bacteria ◽  
And Oxidative Stress

ABSTRACTPlant-pathogenic bacteria are able to integrate information about their environment and adjust gene expression to provide adaptive functions. AlgU, an extracytoplasmic function (ECF) sigma factor encoded byPseudomonas syringae, controls expression of genes for alginate biosynthesis and genes involved with resisting osmotic and oxidative stress. AlgU is active while these bacteria are associated with plants, where its presence supports bacterial growth and disease symptoms. We found that AlgU is an important virulence factor forP. syringaepv. tomato DC3000 but that alginate production is dispensable for disease in host plants. This implies that AlgU regulates additional genes that facilitate bacterial pathogenesis. We used transcriptome sequencing (RNA-seq) to characterize the AlgU regulon and chromatin immunoprecipitation sequencing (ChIP-seq) to identify AlgU-regulated promoters associated with genes directly controlled by this sigma factor. We found that in addition to genes involved with alginate and osmotic and oxidative stress responses, AlgU regulates genes with known virulence functions, including components of the Hrp type III secretion system, virulence effectors, and thehrpLandhrpRStranscription regulators. These data suggest thatP. syringaepv. tomato DC3000 has adapted to use signals that activate AlgU to induce expression of important virulence functions that facilitate survival and disease in plants.IMPORTANCEPlant immune systems produce antimicrobial and bacteriostatic conditions in response to bacterial infection. Plant-pathogenic bacteria are adapted to suppress and/or tolerate these conditions; however, the mechanisms controlling these bacterial systems are largely uncharacterized. The work presented here provides a mechanistic explanation for howP. syringaepv. tomato DC3000 coordinates expression of multiple genetic systems, including those dedicated to pathogenicity, in response to environmental conditions. This work demonstrates the scope of AlgU regulation inP. syringaepv. tomato DC3000 and characterizes the promoter sequence regulated by AlgU in these bacteria.

scholarly journals Isolation of copper and streptomycin resistant phytopathogenic Pseudomonas syringae from lakes and rivers in the central North Island of New Zealand

2008 ◽  
Vol 61 ◽  
pp. 80-85 ◽  
Author(s):  
J.L. Vanneste ◽  
D.A. Cornish ◽  
J. Yu ◽  
R.J. Boyd ◽  
C.E. Morris
Keyword(s):  
New Zealand ◽  
Cytochrome C Oxidase ◽  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
Tobacco Plant ◽  
Hypersensitive Reaction ◽  
Streptomycin Resistance ◽  
Copper Resistance ◽  
Plant Pathogenic Bacteria ◽  
Fluorescent Pigment

Plant pathogenic strains of Pseudomonas syringae were isolated from lakes and rivers in the central North Island of New Zealand These strains were identified by their ability to produce a fluorescent pigment on a modified Kings B medium by their ability to cause a hypersensitive reaction when infiltrated into tobacco plant and by the absence of a cytochrome c oxidase Different aspects of the protocol used to isolate these strains have been assessed Some of the strains isolated and in some cases the majority of them were resistant to copper and/or streptomycin Significantly these plant pathogenic bacteria were isolated from waterways in areas where no agriculture or horticulture is present and waterways used for crop irrigation These results suggest that natural waterways could be a source of inoculum of plant pathogenic bacteria and a source of genes that confer streptomycin resistance and/or copper resistance to these bacteria

Antibiotic Resistance in Plant-Pathogenic Bacteria

2018 ◽  
Vol 56 (1) ◽  
pp. 161-180 ◽  
Author(s):  
George W. Sundin ◽  
Nian Wang
Keyword(s):  
Antibiotic Resistance ◽  
Pseudomonas Syringae ◽  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Plant Pathogens ◽  
Management Strategies ◽  
Resistance Management ◽  
Plant Diseases ◽  
Plant Pathogenic Bacteria ◽  
Continued Use

Antibiotics have been used for the management of relatively few bacterial plant diseases and are largely restricted to high-value fruit crops because of the expense involved. Antibiotic resistance in plant-pathogenic bacteria has become a problem in pathosystems where these antibiotics have been used for many years. Where the genetic basis for resistance has been examined, antibiotic resistance in plant pathogens has most often evolved through the acquisition of a resistance determinant via horizontal gene transfer. For example, the strAB streptomycin-resistance genes occur in Erwinia amylovora, Pseudomonas syringae, and Xanthomonas campestris, and these genes have presumably been acquired from nonpathogenic epiphytic bacteria colocated on plant hosts under antibiotic selection. We currently lack knowledge of the effect of the microbiome of commensal organisms on the potential of plant pathogens to evolve antibiotic resistance. Such knowledge is critical to the development of robust resistance management strategies to ensure the safe and effective continued use of antibiotics in the management of critically important diseases.

scholarly journals Inhibition of Plant-Pathogenic Bacteria by Short Synthetic Cecropin A-Melittin Hybrid Peptides

2006 ◽  
Vol 72 (5) ◽  
pp. 3302-3308 ◽  
Author(s):  
Rafael Ferre ◽  
Esther Badosa ◽  
Lidia Feliu ◽  
Marta Planas ◽  
Emili Montesinos ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Plant Protection ◽  
Bactericidal Effect ◽  
Plant Pathogenic Bacteria ◽  
Lead Compounds ◽  
Human Red Blood Cells ◽  
Hybrid Peptides ◽  
Protease Degradation

ABSTRACT Short peptides of 11 residues were synthesized and tested against the economically important plant pathogenic bacteria Erwinia amylovora, Pseudomonas syringae, and Xanthomonas vesicatoria and compared to the previously described peptide Pep3 (WKLFKKILKVL-NH2). The antimicrobial activity of Pep3 and 22 analogues was evaluated in terms of the MIC and the 50% effective dose (ED50) for growth. Peptide cytotoxicity against human red blood cells and peptide stability toward protease degradation were also determined. Pep3 and several analogues inhibited growth of the three pathogens and had a bactericidal effect at low micromolar concentrations (ED50 of 1.3 to 7.3 μM). One of the analogues consisting of a replacement of both Trp and Val with Lys and Phe, respectively, resulted in a peptide with improved bactericidal activity and minimized cytotoxicity and susceptibility to protease degradation compared to Pep3. The best analogues can be considered as potential lead compounds for the development of new antimicrobial agents for use in plant protection either as components of pesticides or expressed in transgenic plants.

Chemotaxis of some phytopathogenic bacteria to fungal propagules in vitro and in soil

1988 ◽  
Vol 34 (2) ◽  
pp. 196-199 ◽  
Author(s):  
W. C. Lim ◽  
J. L. Lockwood
Keyword(s):  
Pseudomonas Syringae ◽  
Xanthomonas Campestris ◽  
Pathogenic Bacteria ◽  
Erwinia Carotovora ◽  
Bipolaris Sorokiniana ◽  
Macrophomina Phaseolina ◽  
Plant Pathogenic Bacteria ◽  
Fungal Propagules ◽  
Xanthomonas Campestris Pv Campestris

The motile plant pathogenic bacteria Erwinia carotovora pv. carotovora, Pseudomonas syringae pv. phaseolicola, and Xanthomonas campestris pv. campestris were strongly attracted to conidia of Bipolaris sorokiniana, B. victoriae, and to sclerotia of Macrophomina phaseolina and their exudates in vitro and in soil, but not to phosphate buffer or buffer–soil mixtures. Bacteria accumulated radioactivity within 1 h after being placed in exudates from 14C-labelled conidia of B. sorokiniana. After 5 h, radioactivity of the 14C-labelled exudate was reduced to 29–54% of that in the original medium. Exudates from fungal propagules may act as attractants and substrates for motile plant pathogenic bacteria in soil.

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