Erwinia chrysanthemi hrpGenesand Their Involvement in Soft Rot Pathogenesisand Elicitation of the Hypersensitive Response

ABSTRACT The hypersensitive response elicitor harpin (HrpN) of soft rot pathogen Erwinia chrysanthemi strains 3937 and EC16 is secreted via the type III secretion system and remains cell surface bound. Strain 3937 HrpN is essential for cell aggregation, but the C-terminal one-third of the protein is not required for aggregative activity.

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Complete Genome Sequence of Dickeya dadantii subsp. dieffenbachiae Strain S3-1, Isolated from a White-Flowered Calla Lily in Taiwan

Microbiology Resource Announcements ◽

10.1128/mra.00620-21 ◽

2021 ◽

Vol 10 (37) ◽

Author(s):

Yung-An Lee ◽

Kuan-Pei Chen

Keyword(s):

Genome Sequence ◽

Complete Genome Sequence ◽

Complete Genome ◽

Soft Rot ◽

Erwinia Chrysanthemi ◽

Bacterial Soft Rot ◽

Plant Host ◽

Dickeya Dadantii ◽

Content Type ◽

Calla Lily

Erwinia chrysanthemi S3-1 is a bacterial soft rot pathogen of the white-flowered calla lily. The complete genome sequence of the strain was determined and used to reclassify the strain as Dickeya dadantii subsp. dieffenbachiae . The sequence will be useful to study plant host-driven speciation in strains of D. dadantii .

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The Erwinia chrysanthemi 3937 PhoQ Sensor Kinase Regulates Several Virulence Determinants

Journal of Bacteriology ◽

10.1128/jb.188.8.3088-3098.2006 ◽

2006 ◽

Vol 188 (8) ◽

pp. 3088-3098 ◽

Cited By ~ 38

Author(s):

Balakrishnan Venkatesh ◽

Lavanya Babujee ◽

Hui Liu ◽

Pete Hedley ◽

Takashi Fujikawa ◽

...

Keyword(s):

Virulence Factors ◽

Regulatory System ◽

Soft Rot ◽

Erwinia Chrysanthemi ◽

Pcr Analysis ◽

Sensor Kinase ◽

Virulence Determinants ◽

Gene Encoding ◽

Reverse Transcription Pcr ◽

Two Component

ABSTRACT The PhoPQ two-component system regulates virulence factors in Erwinia chrysanthemi, a pectinolytic enterobacterium that causes soft rot in several plant species. We characterized the effect of a mutation in phoQ, the gene encoding the sensor kinase PhoQ of the PhoPQ two-component regulatory system, on the global transcriptional profile of E. chrysanthemi using cDNA microarrays and further confirmed our results by quantitative reverse transcription-PCR analysis. Our results indicate that a mutation in phoQ affects transcription of at least 40 genes, even in the absence of inducing conditions. Enhanced expression of several genes involved in iron metabolism was observed in the mutant, including that of the acs operon that is involved in achromobactin biosynthesis and transport. This siderophore is required for full virulence of E. chrysanthemi, and its expression is governed by the global repressor protein Fur. Changes in gene expression were also observed for membrane transporters, stress-related genes, toxins, and transcriptional regulators. Our results indicate that the PhoPQ system governs the expression of several additional virulence factors and may also be involved in interactions with other regulatory systems.

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Pectin Iyase production in Erwinia chrysanthemi and other soft-rot Erwinia species

Physiological Plant Pathology ◽

10.1016/0048-4059(84)90003-1 ◽

1984 ◽

Vol 24 (3) ◽

pp. 291-302 ◽

Cited By ~ 26

Author(s):

S. Tsuyumu ◽

A.K. Chatterjee

Keyword(s):

Soft Rot ◽

Erwinia Chrysanthemi ◽

Soft Rot Erwinia ◽

Erwinia Species

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PecS and PecT Coregulate the Synthesis of HrpN and Pectate Lyases, Two Virulence Determinants in Erwinia chrysanthemi 3937

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-18-1205 ◽

2005 ◽

Vol 18 (11) ◽

pp. 1205-1214 ◽

Cited By ~ 25

Author(s):

William Nasser ◽

Sylvie Reverchon ◽

Regine Vedel ◽

Martine Boccara

Keyword(s):

Regulatory Region ◽

Soft Rot ◽

Erwinia Chrysanthemi ◽

Virulence Determinants ◽

Pectate Lyases ◽

Heat Stable ◽

Pectinolytic Enzymes ◽

Transcript Elongation ◽

Dna Protein Interaction

Erwinia chrysanthemi strain 3937 is a necrotrophic bacterial plant pathogen. Pectinolytic enzymes and, in particular, pectate lyases play a key role in soft rot symptoms; however, the efficient colonization of plants by E. chrysanthemi requires additional factors. These factors include HrpN (harpin), a heat-stable, glycine-rich hydrophilic protein, which is secreted by the type III secretion system. We investigated the expression of hrpN in E. chrysanthemi 3937 in various environmental conditions and different regulatory backgrounds. Using lacZ fusions, hrpN expression was markedly influenced by the carbon source, osmolarity, growth phase, and growth substrate. hrpN was repressed when pectinolysis started and negatively regulated by the repressors of ectate lyase synthesis, PecS and PecT. Primer extension data and in vitro DNA-protein interaction experiments support a model whereby PecS represses hrpN expression by binding to the hrpN regulatory region and inhibiting transcript elongation. The results suggest coordinated regulation of HrpN and pectate lyases by PecS and PecT. A putative model of the synthesis of these two virulence factors in E. chrysanthemi during pathogenesis is presented.

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Relative Effects on Virulence of Mutations in the sap, pel, and hrp Loci of Erwinia chrysanthemi

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2001.14.3.386 ◽

2001 ◽

Vol 14 (3) ◽

pp. 386-393 ◽

Cited By ~ 42

Author(s):

Emilia López-Solanilla ◽

Arancha Llama-Palacios ◽

Alan Collmer ◽

Francisco García-Olmedo ◽

Pablo Rodríguez-Palenzuela

Keyword(s):

Antimicrobial Peptides ◽

Hypersensitive Response ◽

Double Mutant ◽

Erwinia Chrysanthemi ◽

Potato Tubers ◽

Pectate Lyases

We constructed strains of Erwinia chrysanthemi EC16 with multiple mutations involving three virulence systems in this bacterium, namely pel (coding for the major pectate lyases pelABCE), hrp (hypersensitive response and pathogenicity), and sap (sensitivity to antimicrobial peptides). The relative effects on virulence of those mutations have been analyzed on potato tubers and chicory leaves. In potato tubers, the sap mutation (BT105) had a greater effect in the reduction of the virulence than the pel (CUCPB5006) and hrp (CUCPB5039) mutations. This reduction was similar to that observed in the pel-hrp double mutant (CUCPB5037). The analysis of the strains affected in Pel-Sap (BT106), Hrp-Sap (BT107), and Pel-Hrp-Sap (BT108) suggested that the effects of these mutations are additive. In chicory leaves, the mutation in the sap locus appeared to have a greater effect than in potato tubers. The competitive indices of strains BT105, UM1005 (Pel¯), CUCPB5039, and CUCPB5037 have been estimated in vivo and in vitro. These results indicate that the mutation in the hrp locus can be complemented in vivo by coinfection, whereas the mutations in pel and sap cannot.

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Influence of Soil Saturation and Temperature on Erwinia chrysanthemi Soft Rot of Carrot

Plant Disease ◽

10.1094/pdis.2000.84.6.665 ◽

2000 ◽

Vol 84 (6) ◽

pp. 665-668 ◽

Cited By ~ 13

Author(s):

J. J. Farrar ◽

J. J. Nunez ◽

R. M. Davis

Keyword(s):

Disease Severity ◽

High Temperatures ◽

Weight Reduction ◽

Soft Rot ◽

Saturated Soil ◽

Erwinia Chrysanthemi ◽

Optimum Conditions ◽

First Report ◽

Soil Temperatures ◽

Increasing Temperature

In 1998, soft rot caused by Erwinia chrysanthemi resulted in an estimated loss of 1,800 tons of carrots in California. The disease appeared to be related to unusually high temperatures and excessive irrigation. To determine the optimum conditions for development of soft rot under controlled conditions, pots of carrots inoculated with E. chrysanthemi were saturated with water and incubated at 20, 25, 30, or 35°C. Plants were harvested and examined for disease 12, 24, 36, 48, 72, and 96 h after inoculation. Negligible disease occurred after 12 h. Disease severity and incidence increased with increasing temperature and duration of saturation from 24 to 96 h. In a second experiment, carrot disks were inoculated with three isolates each of E. chrysanthemi and E. carotovora subsp. carotovora and incubated at 15, 20, 25, 30, and 35°C. After 48 h, the disks were washed to remove rotted tissue and reweighed. Neither bacterium reduced carrot disk weight at 15°C. In general, moderate weight reduction occurred at 20 and 25°C. The greatest degree of soft rot was caused by E. chrysanthemi at 30 and 35°C. E. carotovora subsp. carotovora isolates were relatively less virulent than E. chrysanthemi at 30°C and none of the E. carotovora subsp. carotovora isolates reduced carrot disk weight at 35°C. This is the first report of E. chrysanthemi causing soft rot of carrot in California. Based on these results, growers should limit the length of time carrot roots are exposed to saturated soil, especially at high soil temperatures.

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Expression of Erwinia chrysanthemi Pectinase Genes pelI, pelL, and pelZ During Infection of Potato Tubers

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.1999.12.10.845 ◽

1999 ◽

Vol 12 (10) ◽

pp. 845-851 ◽

Cited By ~ 12

Author(s):

Sylwia Jafra ◽

Izabela Figura ◽

Nicole Hugouvieux-Cotte-Pattat ◽

Ewa Lojkowska

Keyword(s):

Type Strain ◽

Wild Type Strain ◽

Pectate Lyase ◽

Soft Rot ◽

Erwinia Chrysanthemi ◽

Potato Tubers ◽

Wild Type ◽

In Planta ◽

Gene Encoding ◽

Glucuronidase Activity

Erwinia chrysanthemi mutants, containing transcriptional fusions of one of the minor pectate lyase genes (pelI, pelL, pelZ) with the reporter gene encoding β-glucuronidase activity, were studied for their ability to cause disease symptoms and to synthesize pectinases after inoculation of potato tubers. The strains affected in pelI and pelL genes displayed reduced virulence on potato tubers, demonstrating the important role of these isoenzymes in soft rot disease. Inactivation of the pelZ gene slightly influences the ability to macerate. Analysis of the bacterial population showed rapid multiplication of bacteria during infection. Similar kinetics of growth were observed for all mutants and for the wild-type strain. Comparison of the mutants and the wild-type strain showed that the pelI, pelL, and pelZ mutants synthesized reduced levels of Pels. The expression of pelZ is fivefold higher in planta than in bacterial cultures. In contrast, both pelI and pelL are highly (10-fold factor) induced in planta, which is characteristic of the plant-inducible pectate lyases.

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First Report of Bacterial Soft Rot of White Flowered Calla Lily Caused by Erwinia chrysanthemi in Taiwan

Plant Disease ◽

10.1094/pdis.2002.86.11.1273a ◽

2002 ◽

Vol 86 (11) ◽

pp. 1273-1273 ◽

Cited By ~ 12

Author(s):

Y.-A. Lee ◽

K.-P. Chen ◽

Y.-C. Chang

Keyword(s):

Soft Rot ◽

Sweet Pepper ◽

Erwinia Chrysanthemi ◽

Maximum Temperature ◽

Gram Negative ◽

First Report ◽

Zantedeschia Aethiopica ◽

Calla Lily ◽

Arginine Dihydrolase ◽

Indole Production

In 2002, soft rot symptoms on white flowered calla lily (Zantedeschia aethiopica) were found in some nurseries in the Yang Ming Shan area, Taipei, Taiwan. The disease was characterized by foul smelling rot and collapse of flower stems. Isolations from diseased flower stems consistently yielded bacterial colonies that were translucent, white, and glistening on nutrient agar. Ten representative isolates were chosen for further characterization. All isolates were gram-negative rods, facultatively anaerobic, sensitive to erythromycin (25 μg/ml), negative for oxidase and arginine dihydrolase, and positive for catalase, phosphatase, tryptophanase (indole production), and lecithinase. They fermented glucose and reduced nitrates to nitrites. The maximum temperature for growth was 37°C. The isolates hydrolyzed gelatin and esculin, produced acids from utilizing D(+)-glucose, melibiose, amygdalin, L(+)-arabinose, D-mannitol, and sucrose, but not from trehalose, lactose, D-sorbitol, or maltose. They degraded pectate and rotted potato, carrot, sweet pepper, and onion slices. Bacterial suspensions (108 CFU/ml) were injected in stems of white flowered calla lily to fulfill Koch's postulates. Control plants were inoculated with sterile distilled water. Inoculated plants were kept in a growth chamber at 30°C. Symptoms developed 1 to 2 days in all four inoculated plants and appeared to be identical to those observed on diseased material in nurseries. The four control plants did not rot. The bacterium was readily reisolated from diseased plants, confirmed to be the inoculated pathogen, and identified as Erwinia chrysanthemi. E. carotovora subsp. carotovora has been reported to cause soft rot of other calla lilies, such as Zantedeschia sp. cvs. Black Magic and Pink Persuasion and Z. elliottiana in Taiwan (1). However, to our knowledge, this is the first report of soft rot caused by E. chrysanthemi on white flowered calla lily in Taiwan. Reference: (1) S. T. Hsu and K. C. Tzeng. Pages 9–18 in: Proc. Int. Conf. Plant Path. Bact., 5th. J. C. Lozano, ed. CIAT, Cali, Colombia, 1981.

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