The histidine-reversible antibiotic herbicolin O produced by Pantoea vagans C9-1 is pantocin A

Pantoea vagans C9-1 is one of the most effective and reliable biocontrol agents against fire blight, and has been commercialized as Blight Ban C9-1. Production of multiple antibiotics contributes to its antagonism of Erwinia amylovora. Here we describe the genetics, chemical isolation and structure of herbicolin O, the histidine-reversible antibiotic produced by P. vagans C9-1. Mutational analyses indicated that biosynthesis of herbicolin O depends on paaAB and a sequence encoding the peptide precursor of pantocin A. The paaABC gene cluster encoding biosynthesis and autoresistance was located within a 28-kb chromosomal genomic island of the complete genome sequence of P. vagans C9-1. The cluster was cloned and expressed in E. coli and purified antibiotic was isolated using improved methods for small peptides. The 1H NMR spectra of the C9-1 antibiotic closely resembled those of pantocin A produced by P. agglomerans Eh318. Detailed analysis of the proton spin systems showed that the chemical shift values and coupling constants of the protons in C9-1 herbicolin O correspond exactly to those of pantocin A. Based on these genetic and chemical analyses, herbicolin O and pantocin A are confirmed to be the same antibiotic

Metabolic Versatility and Antibacterial Metabolite Biosynthesis Are Distinguishing Genomic Features of the Fire Blight Antagonist Pantoea vagans C9-1

Smits THM, Rezzonico F, Kamber T, et al. Metabolic Versatility and Antibacterial Metabolite Biosynthesis Are Distinguishing Genomic Features of the Fire Blight Antagonist Pantoea vagans C9-1. PLoS ONE. 2011;6(7): e22247.Background: Pantoea vagans is a commercialized biological control agent used against the pome fruit bacterial disease fire blight, caused by Erwinia amylovora. Compared to other biocontrol agents, relatively little is currently known regarding Pantoea genetics. Better understanding of antagonist mechanisms of action and ecological fitness is critical to improving efficacy. Principal Findings: Genome analysis indicated two major factors contribute to biocontrol activity: competition for limiting substrates and antibacterial metabolite production. Pathways for utilization of a broad diversity of sugars and acquisition of iron were identified. Metabolism of sorbitol by P. vagans C9-1 may be a major metabolic feature in biocontrol of fire blight. Biosynthetic genes for the antibacterial peptide pantocin A were found on a chromosomal 28-kb genomic island, and for dapdiamide E on the plasmid pPag2. There was no evidence of potential virulence factors that could enable an animal or phytopathogenic lifestyle and no indication of any genetic-based biosafety risk in the antagonist. Conclusions: Identifying key determinants contributing to disease suppression allows the development of procedures to follow their expression in planta and the genome sequence contributes to rationale risk assessment regarding the use of the biocontrol strain in agricultural systems

Production of androgenic dihaploid lines of the disomic tetraploid potato species Solanum acaule ssp. acaule

vokEripainoksia saatavissa tekijöiltä. Yksikön huom.: KJ

Infection of plant material derived from Solanum acaule with Clavibacter michiganensis ssp. sepedonicus : temperature as a determining factor in immunity of S. acaule to bacterial ring rot

v2003okKJB. Yksikön huom.: KJ

Linear Plasmid in the Genome of Clavibacter michiganensis subsp. sepedonicus

Contour-clamped homogeneous electric field gel analysis of genomic DNA of the plant pathogen Clavibacter michiganensis subsp. sepedonicus revealed the presence of a previously unreported extrachromosomal element. This new element was demonstrated to be a linear plasmid. Of 11 strains evaluated, all contained either a 90-kb (pCSL1) or a 140-kb (pCSL2) linear plasmid

Pantocin A, a peptide-derived antibiotic involved in biological control by plant-associated Pantoea species

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)The genus Pantoea contains a broad range of plant-associated bacteria, including some economically important plant pathogens as well as some beneficial members effective as biological control agents of plant pathogens. The most well-characterized representatives of biological control agents from this genus generally produce one or more antimicrobial compounds adding to biocontrol efficacy. Some Pantoea species evaluated as biocontrol agents for fire blight disease of apple and pear produce a histidine-reversible antibiotic. Three commonly studied histidine-reversible antibiotics produced by Pantoea spp. are herbicolin O, MccEh252, and pantocin A. Pantocin A is a novel ribosomally encoded and post-translationally modified peptide natural product. Here, we review the current knowledge on the chemistry, genetics, biosynthesis, and incidence and environmental relevance of pantocin A and related histidine-reversible antibiotics produced by Pantoea

Bacterial ring rot of potato caused by Clavibacter sepedonicus: A successful example of defeating the enemy under international regulations

Background: Bacterial ring rot of potato (Solanum tuberosum) caused by the gram- positive coryneform bacterium Clavibacter sepedonicus is an important quarantine dis-ease threatening the potato industry around the globe. Since its original description in 1906 in Germany, management of ring rot has been a major problem due to the seed-borne nature (via seed tubers not true seeds) of the pathogen allowing the bacterium to be transmitted long distances via infected tubers.Disease symptoms: On growing potato plants: interveinal chlorosis on leaflets leading to necrotic areas and systemic wilt. On infected tubers: vascular tissues become yel-lowish brown with a cheesy texture due to bacterial colonization and decay.Host range: Potato is the main host of the pathogen, but natural infection also occurs on eggplant, tomato, and sugar beet.Taxonomic status of the pathogen: Class: Actinobacteria; Order: Actinomycetales; Family: Microbacteriaceae; Genus: Clavibacter; Species: Clavibacter sepedonicus(Spieckermann and Kotthoff 1914) Li et al. 2018.Synonyms (nonpreferred scientific names): Aplanobacter sepedonicus; Bacterium sepe-donicum; Corynebacterium sepedonicum; Corynebacterium michiganense pv. sepedoni-cum; Clavibacter michiganensis subsp. sepedonicus.Microbiological properties: Gram- positive, club-shaped cells with creamy to yellowish-cream colonies for which the optimal growth temperature is 20–23°C.Distribution: Asia (China, Japan, Kazakhstan, Nepal, North Korea, Pakistan, South Korea, Uzbekistan, the Asian part of Russia), Europe (Belarus, Bulgaria, Czech Republic, Estonia, Finland, Georgia, Germany, Greece, Hungary, Latvia, Lithuania, Norway, Poland, Romania, European part of Russia, Slovakia, Spain, Sweden, Turkey, Ukraine), and North America (Canada, Mexico, USA).Phytosanitary categorization: CORBSE: EPPO A2 list no. 51. EU; Annex designation I/A2

Genome Sequence of the Biocontrol Agent Pantoea vagans Strain C9-1 ▿

Pantoea vagans is a Gram-negative enterobacterial plant epiphyte of a broad range of plants. Here we report the 4.89-Mb genome sequence of P. vagans strain C9-1 (formerly Pantoea agglomerans), which is commercially registered for biological control of fire blight, a disease of pear and apple trees caused by Erwinia amylovora