Complete genome sequence of Pseudomonas viridiflava CFBP 1590: isolated from diseased cherry in France

Pseudomonas viridiflava causes foliar and stem necrosis, as well as stem and root rot on a wide range of plants. We report here the first complete genome of a P. viridiflava strain, isolated from diseased tissue of a cherry tree

Viren-Diagnostik für den Gemüsesektor : frühzeitige Viruserkennung dank der Kombination molekularer Methoden

Technologien zur frühzeitigen Erkennung neu auftretender Pflanzenkrankheiten sind ein wichtiges Instrument im Kampf gegen hohe Produktionsverluste durch Pflanzenkrankheiten in der Landwirtschaft. Mit der Entwicklung und Kombination innovativer Methoden trägt das Projekt «ToViPoRe» zur Prävention und Kontrolle viraler Pathogene bei, welche die Tomatenproduktion in der Schweiz bedrohen. Verläuft der Machbarkeitsnachweis der Methoden erfolgreich, wird die zukünftige Diagnostik stark von diesem Forschungsprojekt profitieren

Comparative genomics and pathogenicity potential of members of the Pseudomonas syringae species complex on Prunus spp

Diseases on Prunus spp. have been associated with a large number of phylogenetically different pathovars and species within the P. syringae species complex. Despite their economic significance, there is a severe lack of genomic information of these pathogens. The high phylogenetic diversity observed within strains causing disease on Prunus spp. in nature, raised the question whether other strains or species within the P. syringae species complex were potentially pathogenic on Prunus spp

High-quality draft genome sequence of xanthomonas arboricola pv. juglandis CPBF 1521, isolated from leaves of a symptomatic walnut tree in Portugal without a past of phytosanitary treatment

Here, we report the draft genome sequence of Xanthomonas arboricola pv. juglandis CPBF 1521, isolated from symptomatic leaves of an ornamental walnut in a public site in Portugal without any record of phytosanitary treatment. This isolate may constitute a genomic reference of a wild-type strain in comparative genomics studies

High-Quality draft genome sequence of xanthomonas sp. strain CPBF 424, a walnut-pathogenic strain with atypical features

We report here the draft genome sequence of Xanthomonas sp. strain CPBF 424, isolated from a diseased walnut tree. Multilocus sequence analysis showed that this walnut-pathogenic isolate is located between the nonpathogenic X. arboricola and X. prunicola clusters. These features make this strain a promising reference to disclose new genetic determinants of pathogenesis

Complete genome sequence data of two Xanthomonas arboricola strains isolated from blueberry plants displaying bacterial leaf blight in Poland

We report here the complete genome sequences of two Xanthomonas arboricola strains isolated in 2013 from blueberry plants displaying bacterial leaf blight in Poland. These two strains – the new blueberry pathogens – were sequenced using a hybrid approach with short- and long-read technologies. The genomes will be used for further analysis of evolution within the species X. arboricola for determining if the strains constitute a new pathovar within the species and improving the molecular diagnostics of this relevant pathogen of blueberry

Erwinia species identification using matrix-assisted laser desorption ionization-time of flight mass spectrometry

Rapid and reliable identification of plant pathogenic bacteria is critical for effective implementation of phytosanitary measures. The genus Erwinia includes a number of economically important plant pathogens such as fire blight agent Erwinia amylovora or Asian pear pathogen Erwinia pyrifoliae, together with closely related plant epiphytes of unknown pathogenicity or even with a potential use for biological control like Erwinia tasmaniensis or Erwinia billingiae, respectively. Current laboratory methods to achieve satisfactory identification and discrimination between species within the Erwinia genus are based on the isolation on semi-selective media, serology, specific PCR and gene locus sequencing: these approaches are complicated and time-consuming, often requiring a priori assumptions over the identity of the isolates. Here we present a streamlined approach based on whole-cell Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry (MALDI-TOF MS) based on the AXIMA mass spectrometer of Shimadzu-Biotech Corp that demonstrates the potential of this technology for quick species identification in plant diagnostics within the genus Erwinia

Complete genome sequences of three isolates of Xanthomonas fragariae, the bacterium responsible for angular leaf spots on strawberry plants

Xanthomonas fragariae is a worldwide spread plant bacterial disease causing angular leaf spots, and thus reducing the yield of production for strawberry fruits. Three isolates with variable geographic and time origins were sequenced with long-read technology (PacBio) to generate finished genomes of virulent strains and observe their variability in content

Transcriptional profile of Salmonella enterica subsp. enterica serovar Weltevreden during alfalfa sprout colonization

Sprouted seeds represent a great risk for infection by human enteric pathogens because of favourable growth conditions for pathogens during their germination. The aim of this study was to identify mechanisms of interactions of Salmonella enterica subsp. enterica Weltevreden with alfalfa sprouts. RNA-seq analysis of S. Weltevreden grown with sprouts in comparison with M9-glucose medium showed that among a total of 4158 annotated coding sequences, 177 genes (4.3%) and 345 genes (8.3%) were transcribed at higher levels with sprouts and in minimal medium respectively. Genes that were higher transcribed with sprouts are coding for proteins involved in mechanisms known to be important for attachment, motility and biofilm formation. Besides gene expression required for phenotypic adaption, genes involved in sulphate acquisition were higher transcribed, suggesting that the surface on alfalfa sprouts may be poor in sulphate. Genes encoding structural and effector proteins of Salmonella pathogenicity island 2, involved in survival within macrophages during infection of animal tissue, were higher transcribed with sprouts possibly as a response to environmental conditions. This study provides insight on additional mechanisms that may be important for pathogen interactions with sprouts

Role of the type VI secretion systems during disease interactions of Erwinia amylovora with its plant host

Background: Type VI secretion systems (T6SS) are widespread among Gram-negative bacteria and have a potential role as essential virulence factors or to maintain symbiotic interactions. Three T6SS gene clusters were identified in the genome of E. amylovora CFBP 1430, of which T6SS-1 and T6SS-3 represent complete T6SS machineries, while T6SS-2 is reduced in its gene content. Results: To assess the contribution of T6SSs to virulence and potential transcriptomic changes of E. amylovora CFBP 1430, single and double mutants in two structural genes were generated for T6SS-1 and T6SS-3. Plant assays showed that mutants in T6SS-3 were slightly more virulent in apple shoots while inducing less disease symptoms on apple flowers, indicating that T6SSs have only a minor effect on virulence of E. amylovora CFBP 1430. The mutations led under in vitro conditions to the differential expression of type III secretion systems, iron acquisition, chemotaxis, flagellar, and fimbrial genes. Comparison of the in planta and in vitro transcriptome data sets revealed a common differential expression of three processes and a set of chemotaxis and motility genes. Additional experiments proved that T6SS mutants are impaired in their motility. Conclusion: These results suggest that the deletion of T6SSs alters metabolic and motility processes. Nevertheless, the difference in lesion development in apple shoots and flower necrosis of T6SS mutants was indicative that T6SSs influences the disease progression and the establishment of the pathogen on host plants