Identification of Biosynthetic Precursors and Optimization of 7-Hydroxytropolone Bioproduction by PA14H7.

Cell-free supernatant of the strain PA14H7 has previously shown interesting activity against Soft Rot (SRP), the bacterial pathogen responsible for blackleg and soft rot diseases in potatoes. A deeper understanding of its mode of action is essential to optimize its use as a biocontrol agent. We previously reported that PA14H7 produces a specialized metabolite, the 7-hydroxytropolone (7-HT), which acts as an iron chelator, limiting the growth of SRP.

A highly conserved ligand-binding site for AccA transporters of antibiotic and quorum-sensing regulator in Agrobacterium leads to a different specificity.

Plants genetically modified by the pathogenic Agrobacterium strain C58 synthesize agrocinopines A and B, whereas those modified by the pathogenic strain Bo542 produce agrocinopines C and D. The four agrocinopines (A, B, C and D) serve as nutrients by agrobacteria and signaling molecule for the dissemination of virulence genes. They share the uncommon pyranose-2-phosphate motif, represented by the l-arabinopyranose moiety in agrocinopines A/B and the d-glucopyranose moiety in agrocinopines C/D, also found in the antibiotic agrocin 84.

Dissimilar gene repertoires of involved in the colonization of lesions and roots of .

and species are necrotrophic pathogens that macerate stems (blackleg disease) and tubers (soft rot disease) of . They proliferate by exploiting plant cell remains. They also colonize roots, even if no symptoms are observed.

A natural single nucleotide mutation in the small regulatory RNA ArcZ of Dickeya solani switches off the antimicrobial activities against yeast and bacteria.

The necrotrophic plant pathogenic bacterium Dickeya solani emerged in the potato agrosystem in Europe. All isolated strains of D. solani contain several large polyketide synthase/non-ribosomal peptide synthetase (PKS/NRPS) gene clusters.

Efficacy of Soft-Rot Disease Biocontrol Agents in the Inhibition of Production Field Pathogen Isolates.

The and bacterial species cause blackleg and soft-rot diseases on potato plants and tubers. Prophylactic actions are essential to conserve a high quality of seed potato tubers. Biocontrol approaches are emerging, but we need to know how efficient biocontrol agents are when facing the natural diversity of pathogens.

Construction of a Transposon Mutant Library in the Pathogen Agrobacterium tumefaciens C58 and Identification of Genes Involved in Gall Niche Exploitation and Colonization.

Agrobacterium tumefaciens is a plant pathogen that causes crown gall disease on a wide range of host species by transferring and integrating a part of its own DNA (T-DNA) into the plant genome. The genes responsible of the above-mentioned processes are well characterized. However, a large number of the mechanisms involved in exploitation and colonization of the galls (also named plant tumors) remain unknown.

Patterns of Genomic Variations in the Plant Pathogen .

The plant pathogen causes soft rot and blackleg diseases in several crops including . Unveiling the patterns of its diversity contributes to understanding the emergence and virulence of this pathogen in potato agro-systems. In this study, we analyzed the genome of several strains exhibiting an atypically high number of genetic variations.

Agrobacterium tumefaciens fitness genes involved in the colonization of plant tumors and roots.

Agrobacterium tumefaciens colonizes the galls (plant tumors) it causes, and the roots of host and nonhost plants. Transposon-sequencing (Tn-Seq) was used to discover A.tumefaciens genes involved in reproductive success (fitness genes) on Solanum lycopersicum and Populus trichocarpa tumors and S.

European Population of : Genomic Diversity, Tuber Maceration Capacity and a Detection Tool for This Rarely Occurring Potato Pathogen.

Enterobacteria belonging to the and genera are responsible for soft rot and blackleg diseases occurring in many crops around the world. Since 2016, the number of described species has more than doubled. However, some new species, such as , are often poorly characterized, and little is known about their genomic and phenotypic variation.

: Genomics, Host Range and Disease Management.

(Pbr) is considered as one of the most virulent species among the Pectobacteriaceae. This species has a broad host range within horticulture crops and is well distributed elsewhere. It has been found to be pathogenic not only in the field causing blackleg and soft rot of potato, but it is also transmitted via storage causing soft rot of other vegetables.

Pattern and causes of the establishment of the invasive bacterial potato pathogen Dickeya solani and of the maintenance of the resident pathogen D. dianthicola.

Invasive pathogens can be a threat when they affect human health, food production or ecosystem services, by displacing resident species, and we need to understand the cause of their establishment. We studied the patterns and causes of the establishment of the pathogen Dickeya solani that recently invaded potato agrosystems in Europe by assessing its invasion dynamics and its competitive ability against the closely related resident D. dianthicola species.

Complete Genome Sequence of the Type Strain Pectobacterium punjabense SS95, Isolated from a Potato Plant with Blackleg Symptoms.

is a newly described species causing blackleg disease in potato plants. Therefore, by the combination of long (Oxford Nanopore Technologies, MinION) and short (Illumina MiSeq) reads, we sequenced the complete genome of SS95, which contains a circular chromosome of 4.793 Mb with a GC content of 50.

Diversity of Pectobacteriaceae Species in Potato Growing Regions in Northern Morocco.

Dickeya and Pectobacterium pathogens are causative agents of several diseases that affect many crops worldwide. This work investigated the species diversity of these pathogens in Morocco, where Dickeya pathogens have only been isolated from potato fields recently. To this end, samplings were conducted in three major potato growing areas over a three-year period (2015-2017).

Species Diversity of and Causing Potato Blackleg Disease in Pakistan.

Potato blackleg is caused by a diverse species of pectinolytic bacteria. In Pakistan, approximately 90% of the pathogens involved belong to Survey (2014 to 2017), sampling, and isolation from different potato growing areas of Punjab, Pakistan depicted an overall disease incidence of approximately 15%. Thirty-six pectinolytic strains confirmed through biochemical and pathogenicity testing were characterized via gene to identify them at the species level.

Elevation of subsp. to species level as sp. nov., proposal of sp. nov. and sp. nov., emended description of and description of sp. nov., isolated from streams and symptoms on diverse plants.

The species corresponds to a complex, including two subspecies with validly published names, two proposed subspecies and two new species, and Recent studies suggested that this complex needed revision. We examined the taxonomic status of 144 strains isolated from a wide range of plant species, various geographical origins and waterways. Sequences of the , and housekeeping genes clustered 114 of these strains together within a not yet described clade.

Dickeya undicola sp. nov., a novel species for pectinolytic isolates from surface waters in Europe and Asia.

Strains 2B12, FVG1-MFV-O17 and FVG10-MFV-A16 were isolated from fresh water samples collected in Asia and Europe. The nucleotide sequences of the gapA barcodes revealed that all three strains belonged to the same cluster within the genus Dickeya. Using 13 housekeeping genes (fusA, rpoD, rpoS, glyA, purA, groEL, gapA, rplB, leuS, recA, gyrB, infB and secY), multilocus sequence analysis confirmed the existence of a new clade.

Biofilm-Constructing Variants of Paraburkholderia phytofirmans PsJN Outcompete the Wild-Type Form in Free-Living and Static Conditions but Not .

Members of the genus colonize diverse ecological niches. Among the plant-associated strains, PsJN is an endophyte with a broad host range. In a spatially structured environment (unshaken broth cultures), biofilm-constructing specialists of PsJN colonizing the air-liquid interface arose at high frequency.

Integrative and deconvolution omics approaches to uncover the Agrobacterium tumefaciens lifestyle in plant tumors.

Agrobacterium tumefaciens is a plant pathogen which provokes galls on roots and stems (crown-gall disease) and colonizes them. Two approaches combining omics were used to decipher the lifestyle of A. tumefaciens in plant tumors: an integrative approach when omics were used on A.

Common and distinctive adaptive traits expressed in Dickeya dianthicola and Dickeya solani pathogens when exploiting potato plant host.

Blackleg and soft rot are devastating diseases on potato stem and tuber caused by Pectobacterium and Dickeya pectinolytic enterobacteria. In European potato cultures, D. dianthicola and D.

Transfer of the waterfall source isolate Pectobacterium carotovorum M022 to Pectobacterium fontis sp. nov., a deep-branching species within the genus Pectobacterium.

Pectobacterium carotovorum M022 has been isolated from a waterfall source in Selangor district (Malaysia). Using genomic and phenotypic tests, we re-examined the taxonomical position of this strain. Based on 14 concatenated housekeeping genes (fusA, rpoD, rpoS, acnA, purA, gyrB, recA, mdh, mtlD, groEL, secY, glyA, gapA and rplB), multi-locus sequence analysis revealed that strain M022 falls into a novel clade separated from the other Pectobacterium species.

The biotroph Agrobacterium tumefaciens thrives in tumors by exploiting a wide spectrum of plant host metabolites.

Agrobacterium tumefaciens is a niche-constructing biotroph that exploits host plant metabolites. We combined metabolomics, transposon-sequencing (Tn-seq), transcriptomics, and reverse genetics to characterize A. tumefaciens pathways involved in the exploitation of resources from the Solanum lycopersicum host plant.

Pectobacterium punjabense sp. nov., isolated from blackleg symptoms of potato plants in Pakistan.

Pectobacterium isolates SS95, SS54 and SS56 were collected from a potato field in the Chiniot district in the plains of the Punjab province, Pakistan. Sequencing of the gapA barcode revealed that these strains belong to a novel phylogenetic group separated from P.ectobacterium wasabiae and Pectobacterium parmentieri species.

Lifestyle of the biotroph Agrobacterium tumefaciens in the ecological niche constructed on its host plant.

Agrobacterium tumefaciens constructs an ecological niche in its host plant by transferring the T-DNA from its Ti plasmid into the host genome and by diverting the host metabolism. We combined transcriptomics and genetics for understanding the A. tumefaciens lifestyle when it colonizes Arabidopsis thaliana tumors.