Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Pectobacterium”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2025

Cell-type-specific defense priming and NHP-dependent systemic immunity against Pectobacterium in Chinese cabbage.

Defense priming is an effective strategy for mounting the defensive capacity of plants. Primed plants undergo minimal changes, enabling rapid, robust responses to subsequent pathogen attack. The cell-type-specific mechanisms underlying priming and systemic immunity remain unclear. Using single-nucleus RNA sequencing (snRNA-seq), we reveal how primed Chinese cabbage coordinates N-hydroxypipecolic acid (NHP)-dependent systemic immunity against Pectobacterium carotovorum. NHP accumulates as a phloem-mobile priming signal. snRNA-seq identified a priming-specific epidermal cell state transition and transcriptional cascade: BrWRKY18-1 activates BrWRKY33-1 expression during priming, initiating NHP-dependent systemic immunity. At post-challenge primed state, pathogenesis-related genes (PRs), such as BrPR3, BrPR4-1, and BrPR4-2, are predominantly expressed in systemic tissues to inhibit infection. Notably, the functionality of these PR genes in immunity necessitates their expression in all cells to effectively enhance defensive resistance. This NHP-transcription factor-PR axis couples mobile signaling to systemic immunity, elucidating cell-type-specific defense priming.

Plant Immunity↗
PubMed2025

Phenotypic profiling of carbon utilization of Pectobacterium brasiliense (Pbr1692).

Pectobacterium brasiliense 1692 (Pbr1692) is a necrotrophic pathogen that infects many crops such as potatoes and ornamental plants and derives nutrients from degraded plant tissue. Previous studies have identified Pbr1692 genes required for ecological fitness and virulence, however there is a lack of information on nutrient utilization in Pbr1692. Carbon source utilization profiling in Pbr1692 could provide a platform to decipher its metabolic flexibility and adaptation. This study assessed the nutrient utilization of Pbr1692 in different carbon sources, using Biolog Phenotypic Microarray (PM). An array of carbon sources utilized by Pbr1692 were identified, 32 carbohydrates and 8 carboxylic acids were among the preferred carbon nutrients utilized by Pbr1692. The PM results also revealed that the citric acid cycle, amino acid metabolism, and pentose phosphate metabolic pathways might be used to produce energy for Pbr1692. In addition, growth of Pbr1692 cells in minimal medium supplemented with citric acid, glucose, and aspartic acid retained the typical rod shape, suggesting that nutrient variation did not influence Pbr1692 cell morphology adaptation. This study provides an understanding on the adaptation of Pbr1692 and lays a foundation for understanding carbon metabolism of Pbr1692.

Carbon↗
PubMed2026

Biocontrol Potential of a Novel Bacillus velezensis Strain Against Major Soft Rot Bacteria Pectobacterium and Dickeya.

Management of soft rot Pectobacteriaceae (SRP) remains a major challenge because effective control options such as bactericides, chemical treatments, or resistant commercial varieties are currently lacking. In a quest for an effective control measure against SRP, we isolated bacteria from soil and potato samples from potato fields across Montana. The bacterial isolates were screened for their effective suppression of major soft rot and blackleg pathogens Pectobacterium brasiliense strain Pb1692 and Dickeya dianthicola strain ME23. We screened more than 3,000 bacterial isolates using inhibition-zone assays on nutrient agar plates. From this collection, we identified a strong antagonist effective against Pb1692 and ME23. This isolate successfully suppressed potato soft rot and blackleg disease in both laboratory and greenhouse evaluations. Genome sequencing identified the bacterial antagonist as Bacillus velezensis strain DN539, which can survive well at 8°C, a potato postharvest storage temperature. We enriched the B. velezensis DN539 supernatant in bioactive fractions, and mass spectrometry analysis identified the bioactive compound as isomers of surfactin. Scanning electron microscopy identified that surfactin-enriched fraction resulted in the leakage of the cellular content of phytobacteria tested in our study in as little as 10 min, followed by complete degradation of bacterial cells within 1 h. The surfactin-enriched fraction also had antimicrobial effects against other economically important phytobacteria such as Erwinia amylovora, Xanthomonas campestris, and Pseudomonas syringae. These indicate that surfactin synthesized by Bacillus velezensis DN539 has potential to be developed as a biocontrol agent against broad range of phytobacteria.

Pectobacterium↗
PubMed1976

[The influence of choramphenicol and streptomycinsulphate on the growth of Pectobacterium carotovorum var. atrosepticum (van Hall) Dowson (author's transl)].

The influence of the antibiotics chloraphenicol (D-threo-form) and streptomycin sulphate against Pectobacterium carotovorum var. atrosepticum (syn. Erwinia carotovora) was investigated in vitro and on potato tubers. Chloramphenicol showed a greater effect as streptomycinsulphate in the applied concentrations. The success of the control of soft rot is determined by the period between the inoculation and the treatment of the tubers. 6 several strains of P. carotovorum var. atrosepticum showed a different sensibility to chloramphenicol and streptomycinsulphate.

Chloramphenicol↗
PubMed2026

Comparative essentialome analysis of six Pectobacteriaceae strains using the TNSEEK pipeline identifies conserved and strain-specific fitness determinants.

Transposon sequencing (Tn-seq) is a powerful technique for defining the essential genes required for bacterial survival. However, gene essentiality can vary significantly across taxonomic levels, and comparing large Tn-seq datasets from multiple strains presents considerable analytical challenges. To address this, we developed TNSEEK, a fully automated bioinformatics pipeline for the systematic and comparative analysis of Tn-seq experiments. We applied TNSEEK to analyse newly generated data for six soft rot Pectobacteriaceae strains, encompassing species from the Dickeya and Pectobacterium genera, grown in a rich medium. This approach identified a core essentialome of 225 genes, primarily involved in fundamental cellular maintenance, conserved across all 6 strains, a set comparable in size to that of the neighbouring Enterobacteriaceae family. Only a few genus-specific essential genes were found, highlighting interesting distinct metabolic capabilities between Dickeya and Pectobacterium genera. In striking contrast, we discovered a large variable essentialome comprising 181 strain-specific genes, many of which are of unknown function. A portion of these strain-specific essential genes are components of defence systems and prophage genomic regions. The unexpected essentiality of selected components of these modules is consistent with cellular dependency on cognate toxic, restriction or immunity functions encoded by defence-associated loci under the tested growth condition. Furthermore, a comparison with the Escherichia coli essentialome demonstrates that discrepancies in gene essentiality can often be attributed to differences in growth conditions, particularly temperature, as well as variations in genetic redundancy. In conclusion, the TNSEEK pipeline provides a reproducible framework for comparative analysis of mariner/Himar1 Tn-seq datasets across multiple strains.

Pectobacterium↗
PubMed1977

Bacterial stalk rot of Maize, its symptoms and host-range.

Stalk rot of maize, caused by Erwinia carotovora f. sp. zeae Sabet (re-designated as Pectobacterium chrysanthemi pathovar. zeae by KELMAN 1974) showed first premature withering and drying up of the uppermost leaves which was soon followed by the lower leaves. The rot either extended from the base upwards (basal rot) or from the top downwards (top rot). In the case of basal rot, the leaves become yellow and the infected tissue becomes brown, soft, and water soaked. Internally, the stalk turns into a soft mass of disintegrated tissue. At this stage the plants usually topple over. A foul odour, accompanied with the presence of dipterous larvae on and in decaying tissues, are the characteristic symptoms of this disease. With the advance of the disease the stalk finally dries up into a conglomeration of dry and shredded or disjointed fibrous tissue. The top rot begins with wilting and drying up ot the tips of middle leaves of the whorl. A decay that continues rapidly spreads downwards throughout the stalk and the affected plants soon droop. The host range studies were suggestive of the fact that the maize pathogen, apart from causing the disease on maize, could produce soft rot in potato, carrot, onion, sugarbeet, sweet potato, papaya, cabbage, and many other plants and could also infect Sorghum vulgare, Pennisetum typhoidium, tobacco, and tomato.

Ecology↗
PubMed1992

Allergic reactions to Erwinia asparaginase in children with acute lymphoblastic leukemia who had previous allergic reactions to Escherichia coli asparaginase.

BACKGROUND: Escherichia coli asparaginase is an active antileukemia agent in the treatment of childhood acute lymphoblastic leukemia. Allergic reactions occurred in 31 of 125 patients (24.8%) treated with weekly high-dose (25,000 IU/m2) intramuscular E. coli asparaginase and necessitated discontinuation of the drug. METHODS: The authors evaluated the toxic effects of Erwinia asparaginase in the 31 children who had allergic reactions to the E. coli preparation. RESULTS: Subsequent allergic reactions to Erwinia asparaginase occurred in 7 of the 31 children (22.6%). In contrast to previous reports with intravenous administration, most allergic reactions to both asparaginase preparations were characterized by mild urticaria that responded to use of diphenhydramine; none of the reactions was life-threatening. CONCLUSIONS: In summary, the authors found Erwinia asparaginase to be an acceptable substitute for E. coli asparaginase for most children who had allergic reactions. Through the use of both E. coli and Erwinia asparaginase, 94% of children could receive their intended asparaginase.

Adolescent↗
PubMed1992

Expression of pehA-bla gene fusions in Erwinia carotovora subsp. carotovora and isolation of regulatory mutants affecting polygalacturonase production.

In vitro gene fusions were constructed between the polygalacturonase-encoding pehA gene of the Erwinia carotovora subsp. carotovora (Ecc) strain SCC3193 and the bla gene of pBR322. The gene fusions obtained (75-2, 75-5 and 75-6) encoded hybrid proteins with the entire signal peptide and 70, 260 or 327 amino acids (aa) of the mature 376 aa PehA protein, respectively, fused to the mature part of the periplasmic beta-lactamase. All three hybrid proteins remained cell-bound in Ecc. High-level expression of the longer fusions 75-5 and 75-6 in Ecc led to reduced growth and viability of the cells. This phenotype was utilized to select for spontaneous extragenic mutations restoring normal cell growth. Two classes of regulatory mutants were obtained by this selection. First, mutants impaired in the production of several exoenzymes, including polygalacturonase, were found. These were phenotypically similar to the previously characterized Exp- mutants. Secondly, mutants specifically impaired in the production of polygalacturonase (designated PehR-), but producing and secreting wild-type levels of pectate lyase and cellulase, were obtained. The PehR- mutations were shown to affect transcriptional activation of the pehA gene. Furthermore, the PehR- as well as PehA- mutants exhibited a reduced virulence phenotype suggesting that polygalacturonase is a virulence factor in Ecc.

Cloning, Molecular↗
PubMed1992

Nucleotide sequence analysis and comparison of the lexA genes from Salmonella typhimurium, Erwinia carotovora, Pseudomonas aeruginosa and Pseudomonas putida.

The complete nucleotide sequences of the lexA genes from Salmonella typhimurium, Erwinia carotovora, Pseudomonas aeruginosa and Pseudomonas putida were determined; the DNA sequences of the lexA genes from these bacteria were 86%, 76%, 61% and 59% similar, respectively, to the Escherichia coli K12 gene. The predicted amino acid sequences of the S. typhimurium, E. carotovora and P. putida LexA proteins are 202 residues long whereas that of P. aeruginosa is 204. Two putative LexA repressor binding sites were localized upstream of each of the heterologous genes, the distance between them being 5 bp in S. typhimurium and E. carotovora, as in the lexA gene of E. coli, and 3 bp in P. putida and P. aeruginosa. The first lexA site present in the lexA operator of all five bacteria is very well conserved. However, the second lexA box is considerably more variable. The Ala-84--Gly-85 bond, at which the LexA repressor of E. coli is cleaved during the induction of the SOS response, is also found in the LexA proteins of S. typhimurium and E. carotovora. Likewise, the amino acids Ser-119 and Lys-156 are present in all of these three LexA repressors. These residues also exist in the LexA proteins of P. putida and P. aeruginosa, but they are displaced by 4 and 6 residues, respectively. Furthermore, the structure and sequence of the DNA-binding domain of the LexA repressor of E. coli are highly conserved in the S. typhimurium, E. carotovora, P. aeruginosa and P. putida LexA proteins.

Amino Acid Sequence↗
PubMed1992

Characterization of the Erwinia carotovora peh gene and its product polygalacturonase.

The peh gene, encoding polygalacturonase (Peh), was identified in Erwinia carotovora strain EC and cloned in Escherichia coli. Recombinant Peh (re-Peh) was purified from E. coli strain 706 containing peh on a recombinant plasmid. The activity of the re-Peh protein is optimal at pH 5.5. The N-terminal and internal amino acid (aa) sequences of re-Peh were determined and compared to the aa sequence deduced from the nucleotide (nt) sequence of the cloned peh. The re-Peh has no similarity, based on either the nt sequences or the deduced aa sequences, to pectate lyases from the same Er. carotovora strain or other organisms.

Amino Acid Sequence↗
PubMed1992

TnblaM: a transposon for directly tagging bacterial genes encoding cell envelope and secreted proteins.

A transposon, TnblaM, designed for the direct selection of bacterial mutants with insertions in genes encoding cell envelope and secreted proteins, was constructed and subcloned into plasmid and bacteriophage lambda delivery vectors. TnblaM is a spectinomycin-resistant derivative of Tn5 with an unexpressed open reading frame encoding mature beta-lactamase (BlaM) at its left end. Therefore, when it inserts into genes in the correct orientation and reading frame, gene fusions encoding hybrid proteins are generated. By introducing TnblaM into bacterial cells and selecting ampicillin-resistant (ApR) colonies, the subset of isolates producing extracytoplasmic BlaM, and hence containing TnblaM inserted in genes encoding secreted proteins and cell envelope proteins, can be directly selected. TnblaM, like TnphoA, can therefore be used to preferentially mutagenise genes encoding extracytoplasmic proteins, but it has the advantage over TnphoA that the desired mutants can be isolated by direct selection (as ApR colonies) rather than by phenotypic screening. Isolates in which TnblaM occupies sites in the chromosome from which it can transpose at high frequency are readily identifiable, and constitute TnblaM donors, with which to simply and efficiently generate rare types of insertion mutants. Moreover, the ApR selection that is used with TnblaM can be fine-tuned to obtain blaM fusions to poorly or well-expressed genes.

Amino Acid Sequence↗
PubMed1992

Expression of the Erwinia carotovora polygalacturonase-encoding gene in Bacillus subtilis: role of signal peptide fusions on production of a heterologous protein.

The pehA gene encoding an endopolygalacturonase (pectinase) of Erwinia carotovora subsp. carotovora has been cloned previously [Saarilahti et al., Mol. Microbiol. 4 (1990) 1037-1044]. We expressed pehA in Bacillus subtilis using a secretion vector based on the promoter and signal sequence of the alpha-amylase (Amy)-encoding gene, amyE, from Bacillus amyloliquefaciens. To test whether the location of the junction between the secretion vector and pehA affects the protein yield, we made four different junctions. Two constructs contained an intact Amy signal sequence, whereas the other two were fusions between the Amy signal sequence and the polygalacturonase (PG) signal sequence. There was approximately fourfold variation in the production efficiency of B. subtilis strains carrying the different constructs. The most efficient construct contained the N-terminal and hydrophobic regions of the Amy signal peptide joined to the C terminus of PG signal peptide. This construct produced, in a shake flask culture, 0.8 g of polygalacturonase per liter of growth medium. In a pulse-chase experiment, the signal peptide of the most efficient construct was rapidly cleaved while cleavage was slow in the other constructs. Our results suggest that fusions containing intact signal peptides, which are common when producing foreign proteins, are not necessarily the most efficient.

Amino Acid Sequence↗
PubMed1992

A general role for the lux autoinducer in bacterial cell signalling: control of antibiotic biosynthesis in Erwinia.

Micro-organisms have evolved complex and diverse mechanisms to sense environmental changes. Activation of a sensory mechanism typically leads to alterations in gene expression facilitating an adaptive response. This may take several forms, but many are mediated by response-regulator proteins. The luxR-encoded protein (LuxR) has previously been characterised as a member of the response-regulator superfamily and is known to respond to the small diffusible autoinducer signal molecule N-(beta-ketocaproyl) homoserine lactone (KHL). Observed previously in only a few marine bacteria, we now report that KHL is in fact produced by a diverse group of terrestrial bacteria. In one of these (Erwinia carotovora), we show that it acts as a molecular control signal for the expression of genes controlling carbapenem antibiotic biosynthesis. This represents the first substantive evidence to support the previous postulate that the lux autoinducer, KHL, is widely involved in bacterial signalling.

4-Butyrolactone↗
PubMed1992

N-(3-oxohexanoyl)-L-homoserine lactone regulates carbapenem antibiotic production in Erwinia carotovora.

Erwinia carotovora A.T.C.C. 39048 produces the antibiotic 1-carbapen-2-em-3-carboxylic acid. A number of mutants with a carbapenem-non-producing phenotype were selected as part of an investigation into the molecular and genetic basis of carbapenem biosynthesis. Cross-feeding studies revealed that the mutants fell into two discrete groups. Group 1 mutants were found to secrete a diffusible low-molecular-mass compound which restored carbapenem production in group 2 mutants. This compound was isolated from the spent culture supernatant of a group 1 mutant using solvent extraction, hydrophobic-interaction chromatography and silica-gel chromatography, and finally purified by reverse-phase semipreparative h.p.l.c. M.s. and n.m.r. spectroscopy revealed that the compound was N-(3-oxohexanoyl)homoserine lactone. Both D- and L-isomers were synthesized, and subsequent analysis by c.d. established that the natural product has the L-configuration. Although carbapenem production was restored by both isomers, dose-response curves indicated that the L-isomer has greater activity, with an induction threshold of about 0.5 micrograms/ml. N-(3-Oxohexanoyl)-L-homoserine lactone is, therefore, an autoregulator of carbapenem biosynthesis rather than a biosynthetic intermediate. This compound is already known for its role in autoinduction of bioluminescence in the marine bacterium Vibrio fischeri. It is also structurally-related to the A- and I-factors which are known to regulate production of antibiotics in some Streptomyces species. Its association in this work with the regulation of carbapenem biosynthesis implies a broader role for autoregulator-controlled gene expression in prokaryotes.

4-Butyrolactone↗
PubMed1992

Construction of a recombinant bacterial human CD4 expression system producing a bioactive CD4 molecule.

The CD4 protein expressed on helper T lymphocytes is a restriction element for major histocompatibility class II immune responses. This molecule is also used by the human immunodeficiency virus as its specific cellular receptor facilitating binding of virus to cells. As soluble forms of CD4 inhibit HIV infection in tissue culture, attention has focused on this molecule. Bacterially produced CD4 would facilitate studies of the biology of the CD4 molecule. However, bacterially expressed CD4 must be refolded for assumption of its interaction with conformationally dependent anti-CD4 monoclonal antibodies as well as the HIV-1 envelope protein gp120. We report here the engineering of an external domain construct of the CD4 gene into a novel expression vector containing the nucleotide sequence encoding the pelB leader peptide of Erwinia carotovara (pDABL), to facilitate correct folding of CD4 in bacteria. Monoclonal antibodies specific for important conformational epitopes of the CD4 molecule were able to bind bacterial colonies containing the pDABL/CD4 vector but not colonies with vector alone. Importantly, recombinant gp120 produced in baculovirus bound specifically to bacterial colonies expressing the CD4 recombinant molecule. This system presents a simple screening mechanism for molecules that bind to the external domain of the CD4 glycoprotein. Vectors such as pDABL will also facilitate the production of large amounts of biologically active proteins in bacteria.

Base Sequence↗
PubMedDate not supplied

Cloning and characterization of a pectate lyase gene from Erwinia carotovora EC153.

A pel gene cloned from strain EC153 of Erwinia carotovora encoded a pectate lyase that macerated plant tissue with moderate efficiency. This gene, called pel153, was sequenced and found to possess considerable homology with a pectate lyase gene from Yersinia pseudotuberculosis. The Yersinia protein, however, was truncated at the carboxyl terminal end relative to the Erwinia gene product and had a lower isoelectric point. The Erwinia pel153 gene was overexpressed in cells of Escherichia coli, and a 56-kDa protein was observed on sodium dodecyl sulfate-polyacrylamide gels. This compares with a molecular weight of 61 kDa for the mature, secreted protein as determined from sequencing data. Southern blot analysis disclosed the presence of the pel153 gene in three different strains of E. carotovora, but mutation of the gene in strain EC153 did not affect its ability to soft-rot potato tubers.

Amino Acid Sequence↗