Molecular Characterization of Natural
            <i>Erwinia pyrifoliae</i>
            Strains Deficient in Hypersensitive Response

Jock, S.; Kim, Wonsik; Barny, Marie‐Anne; Geider, Klaus

doi:10.1128/aem.69.1.679-682.2003

Cited by 16 publications

(13 citation statements)

References 20 publications

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“…In fact, natural deletion of a type III secretion gene cluster in Salmonella spp. (14) and a natural HR-deficient Erwinia pyrifoliae strain have been reported (20). However, the inability of the E. pyrifoliae strain to cause HR was not due to the absence of the hrp genes.…”

Section: Resultsmentioning

confidence: 99%

“…Rather, a single-base mutation of the regulatory gene, hrpL, was responsible for the absence of HR. In E. pyrifoliae, no difference in growth rate was observed in the HR-negative strain when it was coinoculated with an HRpositive strain at different ratios, suggesting that the HR-positive strain aids the growth of the HR-negative variant in host plant tissue (20). WPP17 was isolated from the same tuber as WPP16 and WPP18, two virulent strains able to elicit the HR, suggesting that growth of WPP17 could have been aided by these more virulent strains.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Genomic Diversity of Erwinia carotovora subsp. carotovora and Its Correlation with Virulence

Yap

Barak

Charkowski

2004

Appl Environ Microbiol

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We used genetic and biochemical methods to examine the genomic diversity of the enterobacterial plant pathogen Erwinia carotovora subsp. carotovora. The results obtained with each method showed that E. carotovora subsp. carotovora strains isolated from one ecological niche, potato plants, are surprisingly diverse compared to related pathogens. A comparison of 23 partial mdh sequences revealed a maximum pairwise difference of 10.49% and an average pairwise difference of 2.13%, values which are much greater than the maximum variation (1.81%) and average variation (0.75%) previously reported for Escherichia coli. Pulsed-field gel electrophoresis analysis of I-CeuI-digested genomic DNA revealed seven rrn operons in all E. carotovora subsp. carotovora strains examined except strain WPP17, which had only six copies. We identified 26 I-CeuI restriction fragment length polymorphism patterns and observed significant polymorphism in fragment sizes ranging from 100 to 450 kb for all strains. We detected large plasmids in two strains, including the model strain E. carotovora subsp. carotovora 71. The two least virulent strains had an unusual chromosomal structure, suggesting that a particular pulsotype is correlated with virulence. To compare chromosomal organization of multiple enterobacterial genomes, several genes were mapped onto I-CeuI fragments. We identified portions of the genome that appear to be conserved across enterobacteria and portions that have undergone genome rearrangements. We found that the least virulent strain, WPP17, failed to oxidize cellobiose and was missing several hrp and hrc genes. The unexpected variability among isolates obtained from clonal hosts in one region and in one season suggests that factors other than the host plant, potato, drive the evolution of this common environmental bacterium and key plant pathogen.The plant-pathogenic species Erwinia carotovora is a complex taxon consisting of strains with a range of different phenotypic, biochemical, host range, and genetic characteristics. This species is well suited for studying the ecology, speciation, and pathogenicity of enterobacterial pathogens since it is widespread in the environment, it can infect numerous plant species (42), and many of its virulence genes have been identified, including genes encoding degradative enzymes, diverse regulatory systems, and the type III secretion system (TTSS) (42). E. carotovora is considered a broad-host-range soft rot pathogen because under laboratory conditions it can macerate plant tissues from numerous species. However, in nature, E. carotovora subspecies are associated with particular plant species, showing subspecies adaptation to specific hosts. None of the genetic differences responsible for host specialization in E. carotovora, which is one of the world's most economically important bacterial plant pathogens, have been identified yet.The taxonomy of the soft rot Erwinia is in flux. Recently, Hauben et al. (16) proposed resurrecting the name Pectobacterium, but the majority of the Erwinia r...

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Genomic Diversity of Erwinia carotovora subsp. carotovora and Its Correlation with Virulence

Yap

Barak

Charkowski

2004

Appl Environ Microbiol

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“…Strains lacking a functional T3SS have been reported for the plant pathogens Pseudomonas syringae (22) and Erwinia pyrifoliae (18). P. wasabiae differs from these plant pathogens since it lacks a T3SS, but it is still virulent.…”

Section: Discussionmentioning

confidence: 99%

Phylogeny and Virulence of Naturally Occurring Type III Secretion System-Deficient Pectobacterium Strains

Kim¹,

Perna

et al. 2009

Appl Environ Microbiol

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Pectobacterium species are enterobacterial plant-pathogenic bacteria that cause soft rot disease in diverse plant species. Previous epidemiological studies of Pectobacterium species have suffered from an inability to identify most isolates to the species or subspecies level. We used three previously described DNA-based methods, 16S-23S intergenic transcribed spacer PCR-restriction fragment length polymorphism analysis, multilocus sequence analysis (MLSA), and pulsed-field gel electrophoresis, to examine isolates from diseased stems and tubers and found that MLSA provided the most reliable classification of isolates. We found that strains belonging to at least two Pectobacterium clades were present in each field examined, although representatives of only three of five Pectobacterium clades were isolated. Hypersensitive response and DNA hybridization assays revealed that strains of both Pectobacterium carotovorum and Pectobacterium wasabiae lack a type III secretion system (T3SS). Two of the T3SS-deficient strains assayed lack genes adjacent to the T3SS gene cluster, suggesting that multiple deletions occurred in Pectobacterium strains in this locus, and all strains appear to have only six rRNA operons instead of the seven operons typically found in Pectobacterium strains. The virulence of most of the T3SS-deficient strains was similar to that of T3SS-encoding strains in stems and tubers.The genus Pectobacterium (formerly Erwinia) contains both narrow-and broad-host-range bacterial plant pathogens that cause soft rot, stem rot, wilt, and blackleg in species belonging to over 35% of plant orders (20). Four Pectobacterium species have been described: Pectobacterium atrosepticum, Pectobacterium betavasculorum, Pectobacterium carotovorum, and Pectobacterium wasabiae (9). The recently described organism P. carotovorum subsp. brasiliensis is genetically distinct from previously described Pectobacterium taxa; approximately 82% of its genes are shared with P. atrosepticum, and 84% of its genes are shared with P. carotovorum subsp. carotovorum, while 13% of its genes are found in neither P. atrosepticum nor P. carotovorum subsp. carotovorum (7,10,20). To date, only P. carotovorum subsp. carotovorum and P. atrosepticum have been reported to occur in the same field (14, 21). P. carotovorum subsp. carotovorum is found worldwide, and P. atrosepticum is found in cool climates; while P. carotovorum subsp. brasiliensis has been found only in Brazil, Israel, and the United States, it is likely to have a wider distribution (20). Compared to the ecology and genetics of P. carotovorum subsp. carotovorum and P. atrosepticum, little is known about the ecology and genetics of P. betavasculorum, P. wasabiae, or P. carotovorum subsp. brasiliensis.Pectobacterium strains isolated from potato are diverse based on serology, genome structure, and fatty acid composition (5, 35). Previous epidemiological studies of pectolytic Enterobacteriaceae were complicated by the diversity of this group and the lack of tools capable of placing all isolates ...

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“…that causes bacterial shoot blight of pear was reported to be more closely related to E. pyrifoliae than to the typical E. amylovora (Beer et al 1996;Jock et al 2003aJock et al , 2003bKim et al 2001a;McGhee et al 2002). In addition, a recent comparative study using amplified fragment length polymorphism (AFLP) and groEL sequence analysis showed that Erwinia pathogen of pear in Japan is closely related to E. pyrifoliae and is distinct from E. amylovora (Maxson-Stein et al 2003;Mizuno et al 2000).…”

Section: Introductionmentioning

confidence: 94%

Identification of dspEF, hrpW, and hrpN loci and characterization of the hrpNEp gene in Erwinia pyrifoliae

et al. 2005

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Erwinia pyrifoliae, the causal pathogen of shoot blight in the Asian pear tree (Pyrus pyrifolia cv. Singo), is host-specific and endemic to Korea. To identify the genes associated with the hypersensitive response (HR) and pathogenicity, a genomic library of E. pyrifoliae WT3 was constructed, and the cosmid clone Escherichia coli (pCEP33) was selected. Sequence analysis of 19.7-kb pCEP33 determined disease-specific (dsp) region homolog and approximately 40% of the hrp genes, which included hrpW, hrpN Ep , hrpV, hrpT, hrcC, hrpG, hrpF, and partial hrpE homologs, with respect to the cluster of Erwinia amylovora. Additionally, two open reading frames, ORFD and ORFE, were found downstream of the dspEF region. The results of the sequence analysis showed that the pCEP33 did not contain any hrp regulatory genes or most of the genes encoding components of the Hrp protein secretion system. The hrpN Ep gene of E. pyrifoliae contained five intergenic nucleotide fragment insertions (INFIs) and produced the HR elicitor protein harpin Ep , with a molecular mass of approximately 44 kDa. The purified HrpN Ep protein elicited faster and stronger HR when infiltrated into tobacco leaves than did HrpN Ea from E. amylovora. To observe the role of the hrpL gene in the expression of HrpN Ep , the pEL2 containing hrpL was used to transform E. coli (pCEP33). Expression of HrpN Ep in E. coli (pCEP33 ϩ pEPL2) was detected with an immunoblot using antiserum raised against HrpN Ep , indicating a role of hrpL gene in enhancing the expression of HrpN Ep .

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Molecular Characterization of Natural Erwinia pyrifoliae Strains Deficient in Hypersensitive Response

Cited by 16 publications

References 20 publications

Genomic Diversity of Erwinia carotovora subsp. carotovora and Its Correlation with Virulence

Genomic Diversity of Erwinia carotovora subsp. carotovora and Its Correlation with Virulence

Phylogeny and Virulence of Naturally Occurring Type III Secretion System-Deficient Pectobacterium Strains

Identification of dspEF, hrpW, and hrpN loci and characterization of the hrpNEp gene in Erwinia pyrifoliae

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