Phylogenetic analysis of the genus Pseudomonas was conducted by using combined gyrB and rpoD nucleotide sequences 31 validly described species (a total 125 strains). strains diverged into two major clusters designated intrageneric cluster I (IGC I) II II). IGC further split subclusters, 'P. aeruginosa complex', which included P. aeruginosa, alcaligenes, citronellolis, mendocina, oleovorans pseudoalcaligenes, stutzeri balearica stutzeri. three subclusters that were putida syringae complex'...

The 154-kb plasmid was cured from race 7 strain 1449B of the phytopathogen Pseudomonas syringae pv. phaseolicola ( Pph ). Cured strains lost virulence toward bean, causing hypersensitive reaction in previously susceptible cultivars. Restoration achieved by complementation with cosmid clones spanning a 30-kb region that contained identified avirulence avr ) genes avrD , avrPphC and avrPphF . Single transposon insertions at multiple sites (including one located abolished restoration genomic...

Summary The ability to form biofilms is seen as an increasingly important colonization strategy among both pathogenic and environmental bacteria. A survey of 185 plant‐associated, phytopathogenic, soil river Pseudomonas isolates resulted in 76% producing at the air–liquid (A–L) interface after selection static microcosms. Considerable variation biofilm phenotype was observed, including waxy aggregations, viscous floccular masses, physically cohesive with continuously varying strengths over...

Abstract The apoplast is the arena in which endophytic pathogens such as Pseudomonas syringae grow and interact with plant cells. Using metabolomic ion analysis techniques, this study shows how composition of Phaseolus vulgaris leaf apoplastic fluid changes during first six hours compatible incompatible interactions two strains P. pv. phaseolicola ( Pph ) that differ presence genomic island PPHGI‐1. Leaf inoculation avirulent island‐carrying strain 1302A elicited effector‐triggered immunity...

Bacterial pathogens exhibit significant variation in their genomic content of virulence factors. This reflects the abundance strategies evolved to infect host organisms by suppressing immunity. Molecular arms-races have been a strong driving force for evolution pathogenicity, with often encoding overlapping or redundant functions, such as type III protein secretion effectors and hosts ever more sophisticated immune systems. The pathogens' frequent exposure other microbes, either environment,...

Recent advances in genomics and single-cell analysis have demonstrated the extraordinary complexity reached by microbial populations within their hosts. Communities range from complex multispecies groups to homogeneous differentiating into lineages through genetic or non-genetic mechanisms. Diversity bacterial is recognized as a key driver of evolution animal pathogens. In plants, however, little known about how interactions between different pathogenic non-pathogenic variants host impact on...

Twenty-two cream-coloured bacterial strains were isolated from oak trees affected by acute decline (AOD) in Southern England. Isolates Gram-negative, motile, slightly curved rods, aerobic, non-spore-forming, catalase positive and oxidase positive. 16S rRNA gene sequence analysis placed the two separate phylogenetic clusters Pseudomonas straminea group, with flavescens as closest relative. Multilocus analyses of gyrB, rpoD rpoB genes supported delineation into taxa, which could be...

SUMMARY Pathogenicity islands (PAIs) were first described in uropathogenic E. coli. They are now defined as regions of DNA that contain virulence genes and present the genome pathogenic strains, but absent from or only rarely non-pathogenic variants same related strains. Other features include a variable G+C content, distinct boundaries rest presence to mobile elements such insertion sequences, integrases transposases. Although PAIs have been wide range both plant animal pathogens it has...

Pseudomonas syringae is best known as a plant pathogenic bacterium that causes diseases in multitude of hosts, and it has been used model organism to understand the biology disease. Pathogenic non-pathogenic isolates P. are also commonly found living epiphytes wider environment, including water sources such rivers precipitation. Ice-nucleating strains associated with frost damage crops. The genomes numerous have sequenced molecular genetic studies elucidated many aspects this pathogen's...

Bacterial microcolonies with heterogeneous sizes are formed during colonization of Phaseolus vulgaris by Pseudomonas syringae. Heterogeneous expression structural and regulatory components the P. syringae type III secretion system (T3SS), essential for host apoplast disease development, is likewise detected within plant apoplast. T3SS bistable in homogeneous environment nutrient-limited T3SS-inducing medium, suggesting that subpopulation formation not a response to different environmental...

DNA sequences flanking two avr genes (avrPpiA1 and avrPpiB1) from Pseudomonas syringae pv. pisi show a high degree of similarity. Specific primers designed the conserved regions were used in PCR amplifications with all P. races. As well as amplifying expected avrPpiA- avrPpiB-containing fragments, additional fragments amplified: one contained single open reading frame (ORF1) was found races genomic group II (2, 3A, 4A 6); second fragment frames (ORF2 ORF3), separated by 658 nt, detected All...

Pseudomonas syringae pv. phaseolicola is the causative agent of halo blight in common bean, Phaseolus vulgaris. P. race 4 strain 1302A contains avirulence gene avrPphB (syn. hopAR1), which resides on PPHGI-1, a 106 kb genomic island. Loss PPHGI-1 from following exposure to hypersensitive resistance response (HR) leads evolution strains with altered virulence. Here we have used fluorescent protein reporter systems gain insight into mobility PPHGI-1. Confocal imaging dual-labelled strain, F532...

This book is a collection of contributions from workshop the same title held in Evian, France, 14–17 September 1997 and sponsored by EC Concerted Action Air 3-CT94-2448. The Foreword sets out aims, which were based around three major questions: (1) What are sources molecular variability?; (2) kind variability found among different cultivars or races single species?; (3) kinds interpretations possible to explain variability? book's 19 chapters follow this general scheme. first few consider...

Pseudomonas syringae pv. phaseolicola ( Pph ) race 4 strain 1302A carries avirulence gene avrPphB . Strain RJ3, a sectoral variant from culture, exhibited an extended host range in cultivars of bean and soybean resulting the absence RJ3 chromosome. Complementation with restored phenotype. Both strains showed similar planta growth susceptible cultivars. Analysis indicated loss > 40 kb DNA surrounding Collinearity two genomes was determined for left right junctions deleted region; junction...

SUMMARY The co‐evolution of bacterial plant pathogens and their hosts is a complex dynamic process. Plant resistance can impose stress on invading that lead to, select for, beneficial changes in the genome. Pseudomonas syringae pv. phaseolicola ( Pph ) genomic island PPHGI‐1 carries an effector gene, avrPphB hopAR1 ), which triggers hypersensitive reaction bean plants carrying R3 gene. Interaction between generates antimicrobial environment within plant, resulting excision its loss from...

Pseudomonas syringae pv. syringae, the causal agent of bacterial apical necrosis (BAN) in mango crops, has been isolated different mango-producing areas worldwide. An extensive collection 87 P. strains from trees affected by BAN countries, but mainly Southern Spain, were initially examined repetitive sequence-based polymerase chain reaction (rep-PCR) to analyze genetic diversity with an epidemiological aim. rep-PCR was powerful assessing intrapathovar distribution and also allowing...

Bacteria isolated from onion bulbs suffering bacterial decay in the United States and Norway were previously shown to belong genus Rahnella based on partial housekeeping gene sequences and/or fatty acid analysis. However, many strains could not be assigned any existing species. Additionally, creek water oak as well a strain with bioremediation properties sequences. The taxonomic status of these 21 was investigated using multilocus sequence analysis, whole genome analyses, phenotypic assays...