Browsing by Subject "Pectobacterium"

Sort by: Order: Results:

Now showing items 1-6 of 6
  • Niemi, Outi; Laine, Pia; Koskinen, Patrik; Pasanen, Miia; Pennanen, Ville; Harjunpaa, Heidi; Nykyri, Johanna; Holm, Liisa; Paulin, Lars; Auvinen, Petri; Palva, E. Tapio; Pirhonen, Minna (2017)
    Bacteria of the genus Pectobacterium are economically important plant pathogens that cause soft rot disease on a wide variety of plant species. Here, we report the genome sequence of Pectobacterium carotovorum strain SCC1, a Finnish soft rot model strain isolated from a diseased potato tuber in the early 1980's. The genome of strain SCC1 consists of one circular chromosome of 4,974,798 bp and one circular plasmid of 5524 bp. In total 4451 genes were predicted, of which 4349 are protein coding and 102 are RNA genes.
  • Niemi, Outi; Laine, Pia; Koskinen, Patrik; Pasanen, Miia; Pennanen, Ville; Harjunpää, Heidi; Nykyri, Johanna; Holm, Liisa; Paulin, Lars; Auvinen, Petri; Palva, E. Tapio; Pirhonen, Minna (BioMed Central, 2017)
    Abstract Bacteria of the genus Pectobacterium are economically important plant pathogens that cause soft rot disease on a wide variety of plant species. Here, we report the genome sequence of Pectobacterium carotovorum strain SCC1, a Finnish soft rot model strain isolated from a diseased potato tuber in the early 1980’s. The genome of strain SCC1 consists of one circular chromosome of 4,974,798 bp and one circular plasmid of 5524 bp. In total 4451 genes were predicted, of which 4349 are protein coding and 102 are RNA genes.
  • Fang, Xin (Helsingfors universitet, 2012)
    Bacterial soft rot is one of the most serious diseases affecting potatoes in fields and storages worldwide. Soft rot on potatoes and other crops are caused mainly by Pectobacterium atrosepticum, Pectobacterium carotovorum and several Dickeya species. The disease spreads via many ways and insects are suggested to be important agents in the epidemiology. Evolutionary and geological evidences suggest soil nematodes play essential roles in ecological processes including nutrients cycling, decomposition and disease suppression. Although some studies show that Pectobacteria can survive the digestive tract of the nematodes, it is unclear whether the soil nematodes can be vectors for transmission and dissemination of plant pathogenic bacteria. Moreover, the life span of C. elegans, a free-living and bacterial-feeding nematode, is limited when fed on Pectobacterium. How soft rot bacteria interact with C. elegans and how the nematodes respond to these bacteria are still unknown. Results of this study suggest that Pectobacterium could be disseminated via nematodes on potatoes, indicating that nematodes could serve as vectors in the dissemination of soft rot bacteria on crops. Through the bacterial transmission assay, Pectobacterium is proved to possess a better ability to persist with nematodes compared to E. coli. It seems that pectobacteria have some traits that provide this ability, so Pectobacterium mutants related to Pectobacterium-plant interaction were tested and the expressions C. elegans genes were measured using quantitative polymerase chain reaction (qPCR), aiming to find out genes playing a role in Pectobacterium-nematodes interaction. However, in this study most likely type VI secretion system, putative Flp/Tad-like pilus, flagella, full length lipopolysaccharides, quorum sensing or ExpAS two-component system are not necessary determinants for the interrelationship of Pectobacterium and nematodes.
  • Pasanen, Miia; Waleron, Malgorzata; Schott, Thomas; Cleenwerck, Ilse; Misztak, Agnieszka; Waleron, Krzysztof; Pritchard, Leighton; Bakr, Ramadan; Degefu, Yeshitila; van der Wolf, Jan; Vandamme, Peter; Pirhonen, Minna (2020)
    Pectobacterium strains isolated from potato stems in Finland, Poland and the Netherlands were subjected to polyphasic analyses to characterize their genomic and phenotypic features. Phylogenetic analysis based on 382 core proteins showed that the isolates clustered closest to Pectobacterium polaris but could be divided into two clades. Average nucleotide identity (ANI) analysis revealed that the isolates in one of the clades included the P. polaris type strain, whereas the second Glade was at the border of the species P. polaris with a 96 % ANI value. In silico genome-to-genome comparisons between the isolates revealed values below 70%, patristic distances based on 1294 core proteins were at the level observed between closely related Pectobacterium species, and the two groups of bacteria differed in genome size, G+C content and results of amplified fragment length polymorphism and Biolog analyses. Comparisons between the genomes revealed that the isolates of the atypical group contained SPI-1-type Type III secretion island and genes coding for proteins known for toxic effects on nematodes or insects, and lacked many genes coding for previously characterized virulence determinants affecting rotting of plant tissue by soft rot bacteria. Furthermore, the atypical isolates could be differentiated from P. polaris by their low virulence, production of antibacterial metabolites and a citrate-negative phenotype. Based on the results of a polyphasic approach including genome-to-genome comparisons, biochemical and virulence assays, presented in this report, we propose delineation of the atypical isolates as a novel species Pectobacterium parvum, for which the isolate s0421(T) (CFBP 8630(T)=LMG 30828(T)) is suggested as a type strain.
  • Aho, Jenna (Helsingfors universitet, 2017)
    In a previous study, Pectobacterium strains were isolated from rotten potato tubers and stems. Strains were identified as P. carotovorum subspecies carotovorum by their biochemical properties. In acnA gene sequence analysis the strains isolated from diseased potato stems were different from P. carotovorum subspecies carotovorum type strain and also from strains isolated from rotten potato tubers. However, the strains isolated from rotten potato stems were not able to cause typical blackleg symptoms, like rotting of stems, when inoculated in potato plants. The focus of this master’s thesis was to further study if the new strains are pathogenic in nature or whether they could have arrived to already rotten potato tissue as secondary infection. One goal was to find out if the strains can produce compounds that inhibit growth of known blackleg pathogens, and could they make already contaminated potatoes disease free in a field. This was tested in vitro as well as in a field trial with two potato varieties. As a result the strains isolated from stems were able to produce toxic compounds that inhibited the growth of several common soft rot and blackleg pathogens, whereas compounds produced by the strains isolated from tubers had no effect on the growth of the other bacteria. This suggests that the strains present in stems have properties that make it possible for them to spread from the environment to already infected stem lesions and compete with blackleg and soft rot bacteria already present in the tissue. Blackleg symptoms were absent during the field trial, but in some cases the inoculations caused soft rot of tubers and stunted growth of the inoculated plants. The two potato varieties used in the field trial, Rikea and Fontane, had a different response against the used strains. Although the in vitro results suggested that some of the strains that were originally isolated from stems could act as biological control agents, the results from the field trial contradicted this indicating that the strains might have pathogenic properties, which makes them unsuitable as biological control organisms.
  • van den Bosch, Tijs J. M.; Niemi, Outi; Welte, Cornelia U. (2020)
    Plants of the Brassicales order, including Arabidopsis and many common vegetables, produce toxic isothiocyanates to defend themselves against pathogens. Despite this defence, plant pathogenic microorganisms like Pectobacterium cause large yield losses in fields and during storage of crops. The bacterial gene saxA was previously found to encode isothiocyanate hydrolase that degrades isothiocyanates in vitro. Here we demonstrate in planta that saxA is a virulence factor that can overcome the chemical defence system of Brassicales plants. Analysis of the distribution of saxA genes in Pectobacterium suggests that saxA from three different phylogenetic origins are present within this genus. Deletion of saxA genes representing two of the most common classes from P. odoriferum and P. versatile resulted in significantly reduced virulence on Arabidopsis thaliana and Brassica oleracea. Furthermore, expressing saxA from a plasmid in a potato-specific P. parmentieri strain that does not naturally harbour this gene significantly increased the ability of the strain to macerate Arabidopsis. These findings suggest that a single gene may have a significant role in defining the host range of a plant pathogen.