scholarly journals Gluconate Metabolism Is Required for Virulence of the Soft-Rot Pathogen Pectobacterium carotovorum

2010 ◽  
Vol 23 (10) ◽  
pp. 1335-1344 ◽  
Author(s):  
Beth Mole ◽  
Sohrab Habibi ◽  
Jeffery L. Dangl ◽  
Sarah R. Grant
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Wall ◽  
Environmental Conditions ◽  
Pentose Phosphate Pathway ◽  
Soft Rot ◽  
Pentose Phosphate ◽  
Pectobacterium Carotovorum ◽  
Potato Tubers ◽  
Environmental Signals ◽  
Type Iii

Pectobacterium carotovorum is a ubiquitous soft rot pathogen that uses global virulence regulators to coordinate pathogenesis in response to undefined environmental conditions. We characterize an operon in P. carotovorum required for gluconate metabolism and virulence. The operon contains four genes that are highly conserved among proteobacteria (initially annotated ygbJKLM), one of which was misassigned as a type III secreted effector, (ygbK, originally known as hopAN1). A mutant with a deletion-insertion within this operon is unable to metabolize gluconate, a precursor for the pentose phosphate pathway. The mutant exhibits attenuated growth on the leaves of its host of isolation, potato, and those of Arabidopsis thaliana. Notably, the mutant hypermacerates potato tubers and is deficient in motility. Global virulence regulators that are responsive to cell wall pectin breakdown products and other undefined environmental signals, KdgR and FlhD, respectively, are misregulated in the mutant. The alteration of virulence mediated via changes in transcription of known global virulence regulators in our ygbJ-M operon mutant suggests a role for host-derived catabolic intermediates in P. carotovorum pathogenesis. Thus, we rename this operon in P. carotovorum vguABCD for virulence and gluconate metabolism.

scholarly journals Injectisome T3SS Subunits As Potential Chaperones In The Extracellular Export of Pectobacterium Carotovorum Subsp. Carotovorum Bacteriocins Carocin S1 And Carocin S3 Secreted Via Flagellar T3SS

2021 ◽  
Author(s):  
Hang-Cheng Chen ◽  
Reymund C. Derilo ◽  
Han-Ling Chen ◽  
Tzu-Rung Li ◽  
Ruchi Briam James S. Lagitnay ◽  
...  
Keyword(s):  
Type Iii Secretion ◽  
Insertional Mutagenesis ◽  
Plant Pathogens ◽  
Soft Rot ◽  
Economic Losses ◽  
Pectobacterium Carotovorum ◽  
Secretion Systems ◽  
Unique Type ◽  
Bacterial Flagellum ◽  
Type Iii

Abstract Pectobacterium carotovorum subsp. carotovorum (Pcc) causes soft-rot disease in a wide variety of plants resulting in economic losses worldwide. It produces various types of bacteriocin to compete against related plant pathogens. Studies on how bacteriocins are extracellularly secreted are conducted to understand the mechanism of interbacterial competition. In this study, the secretion of the low-molecular-weight bacteriocins (LMWB) Carocin S1 and Carocin S3 produced by a multiple-bacteriocin producing strain of Pcc, 89-H-4, was investigated. Tn5 insertional mutagenesis was used to generate a mutant, TH22-6, incapable of LMWBs secretion. Sequence and homology analyses of the gene disrupted by transposon Tn5 insertion revealed that the gene sctT, an essential component of the injectisome type III secretion machinery (T3aSS), is required for the secretion of the bacteriocins. This result raised a question regarding the nature of the secretion mechanism of Pcc bacteriocins which was previously discovered to be secreted via T3bSS, a system that utilizes the bacterial flagellum for extracellular secretions. Our previous report has shown that bacteriocin Carocin S1 cannot be secreted by mutants that are defective of T3bSS-related genes such as flhA, flhC, flhD and fliC. We knocked out several genes making up the significant structural components of both T3aSS and T3bSS. The findings led us to hypothesize the potential roles of the T3aSS-related proteins, SctT, SctU and SctV, as flagellar T3SS chaperones in the secretion of Pcc bacteriocins. This current discovery and the findings of our previous study helped us to conceptualize a unique Type III secretion system for bacteriocin extracellular export which is a hybrid of the injectisome and flagellar secretion systems.

scholarly journals Effect of some chemicals on incidence of poato soft rot disease in Bangladesh

2017 ◽  
Vol 52 (2) ◽  
pp. 135-140 ◽  
Author(s):  
MM Rahman ◽  
AA Khan ◽  
IH Mian ◽  
AM Akanda ◽  
MZ Alam
Keyword(s):  
Acetic Acid ◽  
Boric Acid ◽  
Soft Rot ◽  
Pectobacterium Carotovorum ◽  
Potato Tubers ◽  
Soft Rot Disease ◽  
Bleaching Powder ◽  
Carotovorum Subsp ◽  
Rot Disease

Bactericidal effect was investigated by chemicals against potato soft rot bacteria in vitro and in storage. The chemicals were acetic acid, boric acid, bleaching powder, lactic acid, calcium hydroxide, calcium chloride, potassium chloride and sodium hypo-chloride. Among eight  chemicals only three chemicals viz. acetic acid, boric acid and bleaching powder showed bactericidal activity against potato soft rot bacteria  Pectobacterium carotovorum subsp. carotovorum (E. carotovora subsp. carotovora) P-138 in vitro. Based on the results of in vitro experiment three chemicals, acetic acid, boric acid and bleaching powder were used to control soft rot disease of potato in storage. Fresh potato tubers were dipped in 0.2% solution/suspensions of acetic acid, boric acid and bleaching powder for 30 min. Then soft rot bacteria Pectobacterium carotovorum subsp. carotovorum P-138 was inoculated on potato. Finally potatoes were stored for 22 weeks in net bags in sterilized condition. All the three chemicals significantly decreased the infection rate, loss in weight and increased percentage of disease reduction (PDR) of potato. Boric acid was the most effective in controlling the soft rot disease of potato in storage followed by acetic acid and bleaching powder. So these chemicals may be used for seed purpose storage of potato tubers for year round storage at farmer’s level.Bangladesh J. Sci. Ind. Res. 52(2), 135-140, 2017

Pectobacterium parmentieri (black leg disease of potato).

2021 ◽  
Author(s):  
Ewa Lojkowska
Keyword(s):  
Latent Infection ◽  
Seed Tuber ◽  
Bacterial Pathogen ◽  
Soft Rot ◽  
Pectobacterium Carotovorum ◽  
Potato Tubers ◽  
Potato Plants ◽  
The 1960S ◽  
Pectinolytic Bacteria ◽  
Basic Seed

Abstract Pectobacterium parmentieri is a bacterial pathogen of potato present in Europe since the 1960s. The bacterium was earlier classified as Pectobacterium carotovorum. After reclassification of P. carotovorum subsp. carotovorum SCC3193 to P. wasabiae and later on to P. parmentieri, several studies devoted to identification of pectinolytic bacteria in international collections and identification of the strains isolated from infected potato plants have indicated that this bacteria commonly occurs in several regions of Europe, Canada, USA, New Zealand and South Africa. P. parmentieri can cause symptoms of blackleg and soft rot on potato tubers. These diseases are usually a consequence of latent infection of seed potatoes. In the majority of countries pre-basic and basic seed tuber potatoes intended for the production of seed tuber crops should be free of Pectobacterium spp. and Dickeya spp. P. parmentieri is not present on any international or national alert lists.

scholarly journals Arabidopsis thaliana Cells: A Model to Evaluate the Virulence of Pectobacterium carotovorum

2010 ◽  
Vol 23 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Meriam Terta ◽  
Mohamed Kettani-Halabi ◽  
Khadija Ibenyassine ◽  
Daniel Tran ◽  
Patrice Meimoun ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Cell Death ◽  
Plant Cell ◽  
Plant Pathogens ◽  
Plant Cell Wall ◽  
Pectate Lyase ◽  
Soft Rot ◽  
Pectobacterium Carotovorum ◽  
Cell Wall Degrading Enzymes ◽  
Suspension Cells

Pectobacterium carotovorum are economically important plant pathogens that cause plant soft rot. These enterobacteria display high diversity world-wide. Their pathogenesis depends on production and secretion of virulence factors such as plant cell wall–degrading enzymes, type III effectors, a necrosis-inducing protein, and a secreted virulence factor from Xanthomonas spp., which are tightly regulated by quorum sensing. Pectobacterium carotovorum also present pathogen-associated molecular patterns that could participate in their pathogenicity. In this study, by using suspension cells of Arabidopsis thaliana, we correlate plant cell death and pectate lyase activities during coinfection with different P. carotovorum strains. When comparing soft rot symptoms induced on potato slices with pectate lyase activities and plant cell death observed during coculture with Arabidopsis thaliana cells, the order of strain virulence was found to be the same. Therefore, Arabidopsis thaliana cells could be an alternative tool to evaluate rapidly and efficiently the virulence of different P. carotovorum strains.

scholarly journals First Report of Pectobacterium carotovorum subsp. brasiliense Causing Soft Rot and Blackleg of Potatoes in Kenya

Plant Disease ◽  
2014 ◽  
Vol 98 (5) ◽  
pp. 684-684 ◽  
Author(s):  
E. M. Onkendi ◽  
L. N. Maluleke ◽  
L. N. Moleleki
Keyword(s):  
Reference Strain ◽  
Soft Rot ◽  
Negative Control ◽  
Nutrient Agar ◽  
Bootstrap Support ◽  
Pectobacterium Carotovorum ◽  
Petroleum Jelly ◽  
Potato Tubers ◽  
Specific Primers ◽  
Carotovorum Subsp

During the 2012/2013 growing season, potato tubers and stems showing rotting tissue and black discoloration, respectively, were obtained for analysis from Nyandarua and Mau Narok areas of Kenya, where potatoes are widely grown. During this period, more than 50% of the farms across Kenya reported cases of soft rot and blackleg diseases. Soft rot and blackleg diseases account for as much as 1/4 of the annual potato losses in Kenya. Bacteria from infected potato tuber and stem samples were isolated on nutrient agar then transferred to crystal violet polypectate medium (CVP) according to established standard procedures (3). All pit-forming (n = 48) strains were purified on nutrient agar and stored in 30% glycerol at –80°C for further use. All strains grew at 28°C and 37°C. PCR with pel gene specific primers (Y1/Y2) produced a 434-bp product and confirmed that all 48 strains have the gene sequence coding for pectate lyase specific for Pectobacterium spp. (1). Primers (Br1f/L1r) identified 1/3 of these strains as Pectobacterium carotovorum subsp. brasiliense based on their characteristic 322 bp (2). The other Pectobacterium spp. are currently undergoing further characterization. To further identify these pectolytic strains, a multi locus sequence typing (MLST) approach was employed (4). To this end, partial nucleotide sequences of the housekeeping genes mdh and gapA (accession nos. KF72004 to KF72009) showed 92% similarity to the Pcb1692 reference strain in GenBank. These results were in agreement with those obtained by species-specific primers. Phylogenetic analysis of the 679-bp concatenated partial gene sequences grouped strains collected in this study together with Pectobacterium subsp. brasiliense strains identified in other parts of the world with a 98% bootstrap support value. Three randomly selected Kenyan strains and Pcb1692 reference strain were inoculated into potato tubers in our research laboratory by making 1-cm holes into the tubers using a sterile pipette tip and thereafter injecting 10 μl (at 1.0 × 106 cfu/ml) into the tuber for pathogenicity assays. A negative control of 10 mM MgSO4 was included and all the inoculated holes sealed with petroleum jelly to avoid contamination. This experiment consisted of five potato tubers per strain in three independent assays. All three representative strains induced water soaked soft symptoms similar to the symptoms previously observed on infected potato tubers. Furthermore, when bacterial suspensions of 1.0 × 106 cfu/ml isolated strains and the Pcb1692 reference strain were inoculated onto potato stems maintained at 28°C, blackleg and wilting of the stems occurred within a period of 3 to 21 days. No symptoms were observed in potato tubers or stems inoculated with the negative control (MgSO4). PCR with Br1f/L1r primers confirmed that the re-isolated bacteria were P. carotovorum subsp. brasiliense. To our knowledge, this is the first occurrence of P. carotovorum subsp. brasiliense on potatoes in Kenya. References: (1) A. Darrasse et al. Appl. Environ. Microbiol. 60:1437, 1994. (2) V. Duarte et al. J. Appl. Microbiol. 96:535, 2004. (3) L. J. Hyman et al. Potato Res. 44:265, 2001. (4) Ma et al. Phytopathology 97:1150, 2007.

scholarly journals Biological control of Pectobacterium carotovorum subsp. carotovorum, the causal agent of bacterial soft rot in vegetables, in vitro and in vivo tests

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Hassan Abd-El-Khair ◽  
Tarek G. Abdel-Gaied ◽  
Maurice S. Mikhail ◽  
Ahmed I. Abdel-Alim ◽  
Hamdy I. Seif El-Nasr
Keyword(s):  
Potato Tuber ◽  
Soft Rot ◽  
Pectobacterium Carotovorum ◽  
Bacterial Soft Rot ◽  
Potato Tubers ◽  
Soft Rot Disease ◽  
In Vivo Tests ◽  
Rot Disease

Abstract Background Several chemical bactericides were applied for controlling soft rot bacteria, Pectobacterium carotovorum subsp. carotovorum, which causes the destructive soft rot disease to many economically important vegetables, but because of their toxic hazards on human and environment became limit. The biocontrol was applied to control many plant pathogens. Therefore, this work is aimed to study the antagonistic activity of bacterial agents, i.e. Bacillus subtilis, Bacillus pumilus, Bacillus megaterium and Pseudomonas fluorescens, and fugal agents, i.e. Trichoderma harzianum, Trichoderma viride and Trichoderma virens, to control bacterial soft rot disease under in vitro and in vivo tests. Results The tested treatments could protect the potato tubers against the development of soft rot. T. viride and T. virens were highly effective in reducing soft rot symptoms on inoculated potato tuber slices, when applied at the same time or 2 h before pathogen inoculation, while B. megaterium and T. harzianum were highly effective when applied at the same time or 2 h after pathogen inoculation. In whole potato tubers technique, B.pumilus highly protected the stored potato tuber under artificially infection conditions, than P. fluorescens, T. harzianum, B. subtilis, T. viride, T. virens and B. megaterium, respectively. Conclusion Application of fungal agents or specify the bacterial species can play an important role in controlling bacterial soft rot disease in vegetables and increase the stored periods of potato tubers under storage conditions without any toxic effects.

scholarly journals The Gene Encoding NAD-Dependent Epimerase/Dehydratase, wcaG, Affects Cell Surface Properties, Virulence, and Extracellular Enzyme Production in the Soft Rot Phytopathogen, Pectobacterium carotovorum

2019 ◽  
Vol 7 (6) ◽  
pp. 172 ◽  
Author(s):  
Rabiul Islam ◽  
Shyretha Brown ◽  
Ali Taheri ◽  
C. Korsi Dumenyo
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Cell Surface ◽  
Surface Properties ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Soft Rot ◽  
Pectobacterium Carotovorum ◽  
Cell Wall Degrading Enzymes ◽  
Cell Surface Properties

Pectobacterium carotovorum is a gram-negative bacterium that, together with other soft rot Enterobacteriaceae causes soft rot disease in vegetables, fruits, and ornamental plants through the action of exoproteins including plant cell wall-degrading enzymes (PCWDEs). Although pathogenicity in these bacteria is complex, virulence levels are proportional to the levels of plant cell wall-degrading exoenzymes (PCWDEs) secreted. Two low enzyme-producing transposon Tn5 mutants were isolated, and compared to their parent KD100, the mutants were less virulent on celery petioles and carrot disks. The inactivated gene responsible for the reduced virulence phenotype in both mutants was identified as wcaG. The gene, wcaG (previously denoted fcl) encodes NAD-dependent epimerase/dehydratase, a homologue of GDP-fucose synthetase of Escherichia coli. In Escherichia coli, GDP-fucose synthetase is involved in the biosynthesis of the exopolysaccharide, colanic acid (CA). The wcaG mutants of P. carotovorum formed an enhanced level of biofilm in comparison to their parent. In the hydrophobicity test the mutants showed more hydrophobicity than the parent in hexane and hexadecane as solvents. Complementation of the mutants with extrachromosomal copies of the wild type gene restored these functions to parental levels. These data indicate that NAD-dependent epimerase/dehydratase plays a vital rule in cell surface properties, exoenzyme production, and virulence in P. carotovorum.

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