scholarly journals Contribution of the non-effector members of the HrpL regulon, iaaL and matE, to the virulence of Pseudomonas syringae pv. tomato DC3000 in tomato plants

2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Melissa G. Castillo-Lizardo ◽  
Isabel M. Aragón ◽  
Vivian Carvajal ◽  
Isabel M. Matas ◽  
María Luisa Pérez-Bueno ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Tomato Dc3000 ◽  
Tomato Plants

scholarly journals Induction of Pseudomonas syringae pv. tomato DC3000 MexAB-OprM Multidrug Efflux Pump by Flavonoids Is Mediated by the Repressor PmeR

2011 ◽  
Vol 24 (10) ◽  
pp. 1207-1219 ◽  
Author(s):  
Paola Vargas ◽  
Antonia Felipe ◽  
Carmen Michán ◽  
María-Trinidad Gallegos
Keyword(s):  
Pseudomonas Syringae ◽  
Efflux Pump ◽  
Regulatory Gene ◽  
Multidrug Efflux ◽  
Tomato Dc3000 ◽  
Multidrug Efflux Pump ◽  
Tomato Plants ◽  
In Vivo Experiments

In this study, we have analyzed the expression of the Pseudomonas syringae pv. tomato DC3000 mexAB-oprM efflux pump operon and of the regulatory gene pmeR, and we have investigated the role of the PmeR protein on transcription from both promoters. We demonstrate that mexAB-oprM and pmeR are expressed in vivo at a relatively high and moderate basal level, respectively, which, in both cases, increases in the presence of different flavonoids and other compounds, such as butyl and methylparaben. We show that PmeR is the local repressor of the mexAB-oprM promoter and is able to regulate its own expression. The mechanism for this regulation includes binding to a pseudopalindromic operator site which overlaps both mexAB-oprM and pmeR promoters. We have also proven that flavonoids are able to interact with PmeR and induce a conformational change that interferes with the DNA binding ability of PmeR, thereby modulating mexAB-oprM and pmeR expression. Finally, we demonstrate by in vivo experiments that the PmeR/MexAB-OprM system contributes to the colonization of tomato plants. These results provide new insight into a transcriptional regulator and a transport system that play essential roles in the ability of P. syringae pv. tomato DC3000 to resist the action of flavonoids produced by the host.

scholarly journals CorR Regulates Multiple Components of Virulence in Pseudomonas syringae pv. tomato DC3000

2006 ◽  
Vol 19 (7) ◽  
pp. 768-779 ◽  
Author(s):  
Aswathy Sreedharan ◽  
Alejandro Penaloza-Vazquez ◽  
Barbara N. Kunkel ◽  
Carol L. Bender
Keyword(s):  
Pseudomonas Syringae ◽  
Biosynthetic Pathway ◽  
Response Regulator ◽  
Tomato Dc3000 ◽  
Tomato Plants ◽  
Coronafacic Acid ◽  
Multiple Components ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Polymerase Chain

The phytotoxin coronatine (COR) is produced by various pathovars of Pseudomonas syringae, including P. syringae pv. tomato DC3000, which is pathogenic on crucifers and tomato, and P. syringae pv. glycinea PG4180, a soybean pathogen. The COR molecule contains two distinct components, coronafacic acid (CFA) and coronamic acid (CMA), which are intermediates in the COR biosynthetic pathway. In P. syringae pv. tomato DC3000, it is not clear whether corR, which encodes a response regulator, positively regulates CFA and CMA synthesis as it does in P. syringae pv. glycinea PG4180. In this study, a corR mutant of P. syringae pv. tomato DC3000 was constructed and was shown to be defective in the production of COR, CFA, and CMA. Furthermore, disease severity was greatly reduced in tomato plants inoculated with the corR mutant compared with wild-type P. syringae pv. tomato DC3000. We also showed that a mutation in hrpL, which encodes an alternate RNA polymerase sigma factor (σL) required for the expression of genes encoding components of the type III secretion system, abrogated production of COR in P. syringae pv. tomato DC3000. The presence of a potential hrp box, the recognition site for σL, upstream of corR suggested that corR might be regulated by hrpL. This was confirmed in reverse-transcription polymerase chain reaction experiments showing that the upstream effector gene holPtoAA, which was associated with the hrp box, was cotranscribed with corR. Furthermore, studies also were conducted to investigate whether mutations in corR had effects on the expression of hrpL. The corR mutant of P. syringae pv. tomato DC3000 showed both a reduction and delay in the expression of hrpL and was impaired in its ability to elicit a hypersensitive response on Nicotiana benthamiana. A putative CorR-binding site was identified upstream of hrpL, and gel shift studies confirmed the binding of CorR to this region. These results indicate that corR directly impacts the expression of the hrp regulon in P. syringae.

scholarly journals A Pseudomonas syringae pv. tomato DC3000 Hrp (Type III Secretion) Deletion Mutant Expressing the Hrp System of Bean Pathogen P. syringae pv. syringae 61 Retains Normal Host Specificity for Tomato

2003 ◽  
Vol 16 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Derrick E. Fouts ◽  
Jorge L. Badel ◽  
Adela R. Ramos ◽  
Ryan A. Rapp ◽  
Alan Collmer
Keyword(s):  
Host Range ◽  
Resistance Gene ◽  
Host Specificity ◽  
Pseudomonas Syringae ◽  
Type Iii Secretion ◽  
Secretion System ◽  
Effector Proteins ◽  
Tomato Dc3000 ◽  
Tomato Plants ◽  
Type Iii

The plant pathogenic species Pseudomonas syringae is divided into numerous pathovars based on host specificity. For example, P. syringae pv. tomato DC3000 is pathogenic on tomato and Arabidopsis, whereas P. syringae pv. syringae 61 is pathogenic on bean. The ability of P. syringae strains to elicit the hypersensitive response (HR) in non-hosts or be pathogenic (or parasitic) in hosts is dependent on the Hrp (type III secretion) system and effector proteins this system is thought to inject into plant cells. To test the role of the Hrp system in determining host range, the hrp/hrc gene cluster (hrpK through hrpR) was deleted from DC3000 and complemented in trans with the orthologous cluster from strain 61. Mutant CUCPB5114 expressing the bean pathogen Hrp system on plasmid pCPP2071 retained the ability of wild-type DC3000 to elicit the HR in bean, to grow and cause bacterial speck in tomato, and to elicit a cultivar-specific (gene-for-gene) HR in tomato plants carrying the Pto resistance gene. However, the symptoms produced in compatible tomato plants involved markedly reduced chlorosis, and CUCPB5114(pCPP2071) did not grow or produce symptoms in Arabidopsis Col-0 although it was weakly virulent in NahG Arabidopsis. A hypersensitive-like collapse was produced by CUCPB5114(pCPP2071) in Arabidopsis Col-0 at 1 × 107 CFU/ml, but only if the bacteria also expressed AvrB, which is recognized by the RPM1 resistance gene in Col-0 and confers incompatibility. These observations support the concept that the P. syringae effector proteins, rather than secretion system components, are the primary determinants of host range at both the species and cultivar levels of host specificity.

scholarly journals The Phytotoxin Coronatine Contributes to Pathogen Fitness and Is Required for Suppression of Salicylic Acid Accumulation in Tomato Inoculated with Pseudomonas syringae pv. tomato DC3000

2007 ◽  
Vol 20 (8) ◽  
pp. 955-965 ◽  
Author(s):  
Srinivasa Rao Uppalapati ◽  
Yasuhiro Ishiga ◽  
Tamding Wangdi ◽  
Barbara N. Kunkel ◽  
Ajith Anand ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Pseudomonas Syringae ◽  
Defense Responses ◽  
Tomato Dc3000 ◽  
Defense Proteins ◽  
Tomato Plants ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Salicylic Acid Accumulation ◽  
Pathogen Fitness

The roles of the phytotoxin coronatine (COR) and salicylic acid (SA)-mediated defenses in the interaction of Pseudomonas syringae pv. tomato DC3000 and tomato (Solanum lycopersicum) were investigated. Unlike findings reported for Arabidopsis thaliana, DC3000 mutants impaired for production of COR or one of its components, coronafacic acid (CFA) or coronamic acid (CMA), induced distinctly different disease lesion phenotypes in tomato. Tomato plants inoculated with the CFA- CMA- mutant DB29 showed elevated transcript levels of SlICS, which encodes isochorismate synthase, an enzyme involved in SA biosynthesis in S. lycopersicum. Furthermore, expression of genes encoding SA-mediated defense proteins were elevated in DB29-inoculated plants compared with plants inoculated with DC3000, suggesting that COR suppresses SlICS-mediated SA responses. Sequence analysis of SlICS revealed that it encodes a protein that is 55 and 59.6% identical to the A. thaliana ICS-encoded proteins AtICS1 and AtICS2, respectively. Tomato plants silenced for SlICS were hypersusceptible to DC3000 and accumulated lower levels of SA after infection with DC3000 compared with inoculated wild-type tomato plants. Unlike what has been shown for A. thaliana, the COR- mutant DB29 was impaired for persistence in SlICS-silenced tomato plants; thus, COR has additional roles in virulence that are SA independent and important in the latter stages of disease development. In summary, the infection assays, metabolic profiling, and gene expression results described in this study indicate that the intact COR molecule is required for both suppression of SA-mediated defense responses and full disease symptom development in tomato.

scholarly journals Pseudomonas syringae pv. tomato DC3000 Improves Escherichia coli O157:H7 Survival in Tomato Plants

2019 ◽  
Vol 29 (12) ◽  
pp. 1975-1981
Author(s):  
Min Namgung ◽  
Yeon-Jeong Lim ◽  
Min Kyu Kang ◽  
Chang-Sik Oh ◽  
Duck-Hwan Park
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Syringae ◽  
Escherichia Coli O157 ◽  
Tomato Dc3000 ◽  
Tomato Plants

scholarly journals RNA-seq analysis reveals the role of red light in resistance against Pseudomonas syringae pv. tomato DC3000 in tomato plants

BMC Genomics ◽  
2015 ◽  
Vol 16 (1) ◽  
pp. 120 ◽  
Author(s):  
You-Xin Yang ◽  
Meng-Meng Wang ◽  
Yan-Ling Yin ◽  
Eugen Onac ◽  
Guo-Fu Zhou ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Red Light ◽  
Rna Seq ◽  
Tomato Dc3000 ◽  
Tomato Plants

scholarly journals The Pseudomonas syringae pv. tomatoDC3000 Type III Effector HopF2 Has a Putative Myristoylation Site Required for Its Avirulence and Virulence Functions

2006 ◽  
Vol 19 (2) ◽  
pp. 130-138 ◽  
Author(s):  
Alexandre Robert-Seilaniantz ◽  
Libo Shan ◽  
Jian-Min Zhou ◽  
Xiaoyan Tang
Keyword(s):  
Plasma Membrane ◽  
Pseudomonas Syringae ◽  
Mutational Analysis ◽  
Mitochondrial Genes ◽  
Bacterial Virulence ◽  
Start Codon ◽  
Effector Protein ◽  
Tomato Dc3000 ◽  
Tomato Plants ◽  
Type Iii

The HopPtoF locus in Pseudomonas syringae pv. tomato DC3000 harbors two genes, ShcF and HopF2 (previously named ShcFPto and HopFPto), that encode a type III chaperone and a cognate effector protein, respectively. The HopF2 gene has a rare initiation codon, ATA that was reported to be functional only in mitochondrial genes. Here, we report that the native HopPtoF locus of DC3000 confers an avirulence function in tobacco W38 plants, indicating that the ATA start codon directs the synthesis of a functional effector. However, disruption of HopF2 in DC3000 genome did not alter the bacterial virulence in tomato plants. The HopPtoF locus displayed a measurable virulence activity in two strains of P. syringae pv. tomato when the ATA start codon was changed to ATG, and this change also elevated the avirulence function in W38 plants. HopF2 contains a putative myristoylation site. Mutational analysis indicated that this site is required for plasma membrane localization and virulence and avirulence activities of HopF2.

scholarly journals Zinc phosphate protects tomato plants against Pseudomonas syringae pv. tomato

2021 ◽  
Author(s):  
Mara Quaglia ◽  
Marika Bocchini ◽  
Benedetta Orfei ◽  
Roberto D’Amato ◽  
Franco Famiani ◽  
...  
Keyword(s):  
Disease Severity ◽  
Pseudomonas Syringae ◽  
Zinc Phosphate ◽  
Plant Defence ◽  
In Planta ◽  
Tomato Plants ◽  
Pathogenesis Related Protein ◽  
Defence Responses ◽  
Plant Defence Responses

AbstractThe purpose of this study was to determine whether zinc phosphate treatments of tomato plants (Solanum lycopersicum L.) can attenuate bacterial speck disease severity through reduction of Pseudomonas syringae pv. tomato (Pst) growth in planta and induce morphological and biochemical plant defence responses. Tomato plants were treated with 10 ppm (25.90 µM) zinc phosphate and then spray inoculated with strain DAPP-PG 215, race 0 of Pst. Disease symptoms were recorded as chlorosis and/or necrosis per leaf (%) and as numbers of necrotic spots. Soil treatments with zinc phosphate protected susceptible tomato plants against Pst, with reductions in both disease severity and pathogen growth in planta. The reduction of Pst growth in planta combined with significantly higher zinc levels in zinc-phosphate-treated plants indicated direct antimicrobial toxicity of this microelement, as also confirmed by in vitro assays. Morphological (i.e. callose apposition) and biochemical (i.e., expression of salicylic-acid-dependent pathogenesis-related protein PR1b1 gene) defence responses were induced by the zinc phosphate treatment, as demonstrated by histochemical and qPCR analyses, respectively. In conclusion, soil treatments with zinc phosphate can protect tomato plants against Pst attacks through direct antimicrobial activity and induction of morphological and biochemical plant defence responses.

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