Sensitivity of Pectobacterium carotovorum to hydroxytyrosol-rich extracts and their effect on the development of soft rot in potato tubers during storage

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 farmers level.Bangladesh J. Sci. Ind. Res. 52(2), 135-140, 2017

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Pectobacterium parmentieri (black leg disease of potato).

10.1079/cpc.48069201.20210099913 ◽

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.

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

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-03-10-0067 ◽

2010 ◽

Vol 23 (10) ◽

pp. 1335-1344 ◽

Cited By ~ 15

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.

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

Plant Disease ◽

10.1094/pdis-09-13-0988-pdn ◽

2014 ◽

Vol 98 (5) ◽

pp. 684-684 ◽

Cited By ~ 5

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.

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

Bulletin of the National Research Centre ◽

10.1186/s42269-021-00491-4 ◽

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.

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Bioactivity of Various Ethanolic Plant Extracts against Pectobacterium carotovorum subsp. carotovorum Causing Soft Rot of Potato Tubers

Indian Phytopathology ◽

10.24838/ip.2017.v70.i4.76990 ◽

2017 ◽

Vol 70 (4) ◽

Author(s):

K. A. Bhat ◽

H. S. Viswanath ◽

N. A. Bhat ◽

T. A. Wani

Keyword(s):

Plant Extracts ◽

Soft Rot ◽

Pectobacterium Carotovorum ◽

Potato Tubers

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Isolation and efficacy of two bacterial strains antagonists of Erwinia amylovora and Pectobacterium carotovorum

Egyptian Journal of Biological Pest Control ◽

10.1186/s41938-021-00443-0 ◽

2021 ◽

Vol 31 (1) ◽

Author(s):

M’hamed BENADA ◽

Boualem BOUMAAZA ◽

Sofiane BOUDALIA ◽

Omar KHALADI

Keyword(s):

Fire Blight ◽

Erwinia Amylovora ◽

Bacterial Species ◽

Crop Protection ◽

Soft Rot ◽

Causal Agent ◽

Plant Diseases ◽

Ecological Niches ◽

Pectobacterium Carotovorum ◽

Bacterial Strains

Abstract Background The development of ecofriendly tools against plant diseases is an important issue in crop protection. Screening and selection process of bacterial strains antagonists of 2 pathogenic bacterial species that limit very important crops, Erwinia amylovora, the causal agent of the fire blight disease, and Pectobacterium carotovorum, the causal agent of bacterial potato soft rot, were reported. Bacterial colonies were isolated from different ecological niches, where both pathogens were found: rhizosphere of potato tubers and fruits and leaves of pear trees from the northwest region of Algeria. Direct and indirect confrontation tests against strains of E. amylovora and P. carotovorum were performed. Results Results showed a significant antagonistic activity against both phytopathogenic species, using direct confrontation method and supernatants of cultures (p<0.005). In vitro assays showed growth inhibitions of both phytopathogenic species. Furthermore, results revealed that the strains of S. plymuthica had a better inhibitory effect than the strains of P. fluorescens against both pathogens. In vivo results on immature pear fruits showed a significant decrease in the progression of the fire blight symptoms, with a variation in the infection index from one antagonistic strain to another between 31.3 and 50%, and slice of potato showed total inhibition of the pathogen (P. carotovorum) by the antagonistic strains of Serratia plymuthica (p<0.005). Conclusion This study highlighted that the effective bacteria did not show any infection signs towards plant tissue, and considered as a potential strategy to limit the fire blight and soft rot diseases.

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