Polyhydroxyalkanoate production by the plant beneficial rhizobacterium Pseudomonas chlororaphis PCL1606 influences survival and rhizospheric performance.

Pseudomonas chlororaphis PCL1606 (PcPCL1606) is a model rhizobacterium used to study beneficial bacterial interactions with the plant rhizosphere. Many of its beneficial phenotypes depend on the production of the antifungal compound 2-hexyl, 5-propyl resorcinol (HPR). Transcriptomic analysis of PcPCL1606 and the deletional mutant in HPR production ΔdarB strain, assigned an additional regulatory role to HPR, and allowed the detection of differentially expressed genes during the bacterial interaction with the avocado rhizosphere.

Interplay between rhizospheric strains lays the basis for beneficial bacterial consortia.

(Pc) representatives are found as part of the rhizosphere-associated microbiome, and different rhizospheric Pc strains frequently perform beneficial activities for the plant. In this study we described the interactions between the rhizospheric Pc strains PCL1601, PCL1606 and PCL1607 with a focus on their effects on root performance. Differences among the three rhizospheric Pc strains selected were first observed in phylogenetic studies and confirmed by genome analysis, which showed variation in the presence of genes related to antifungal compounds or siderophore production, among others.

Insecticidal features displayed by the beneficial rhizobacterium Pseudomonas chlororaphis PCL1606.

The biocontrol rhizobacterium Pseudomonas chlororaphis is one of the bacterial species of the P. fluorescens group where insecticide fit genes have been found. Fit toxin, supported with other antimicrobial compounds, gives the bacterial the ability to repel and to fight against eukaryotic organisms, such as nematodes and insect larvae, thus protecting the plant host and itself.

Aer Receptors Influence the PCL1606 Lifestyle.

PCL1606 (PcPCL1606) is a rhizobacterium isolated from avocado roots, which is a favorable niche for its development. This strain extensively interacts with plant roots and surrounding microbes and is considered a biocontrol rhizobacterium. Genome sequencing has shown the presence of thirty-one potential methyl-accepting chemotaxis proteins (MCPs).

The diguanylate cyclase AdrA regulates flagellar biosynthesis in Pseudomonas fluorescens F113 through SadB.

Flagellum mediated motility is an essential trait for rhizosphere colonization by pseudomonads. Flagella synthesis is a complex and energetically expensive process that is tightly regulated. In Pseudomonas fluorescens, the regulatory cascade starts with the master regulatory protein FleQ that is in turn regulated by environmental signals through the Gac/Rsm and SadB pathways, which converge in the sigma factor AlgU.

Fitness Features Involved in the Biocontrol Interaction of With Host Plants: The Case Study of PcPCL1606.

The goal of this mini review is to summarize the relevant contribution of some beneficial traits to the behavior of the species , and using that information, to give a practical point of view using the model biocontrol strain PCL1606 (PcPCL1606). Among the group of plant-beneficial rhizobacteria, has emerged as a plant- and soil-related bacterium that is mainly known because of its biological control of phytopathogenic fungi. Many traits have been reported to be crucial during the multitrophic interaction involving the plant, the fungal pathogen and the soil environment.

The Compound 2-Hexyl, 5-Propyl Resorcinol Has a Key Role in Biofilm Formation by the Biocontrol Rhizobacterium PCL1606.

The production of the compound 2-hexyl-5-propyl resorcinol (HPR) by the biocontrol rhizobacterium PCL1606 (PcPCL1606) is crucial for fungal antagonism and biocontrol activity that protects plants against the phytopathogenic fungus . The production of HPR is also involved in avocado root colonization during the biocontrol process. This pleiotrophic response prompted us to study the potential role of HPR production in biofilm formation.

AmrZ is a major determinant of c-di-GMP levels in Pseudomonas fluorescens F113.

The transcriptional regulator AmrZ is a global regulatory protein conserved within the pseudomonads. AmrZ can act both as a positive and a negative regulator of gene expression, controlling many genes implicated in environmental adaption. Regulated traits include motility, iron homeostasis, exopolysaccharides production and the ability to form biofilms.

Classification of Isolates from the Complex into Phylogenomic Groups Based in Group-Specific Markers.

The complex of species includes plant-associated bacteria with potential biotechnological applications in agriculture and environmental protection. Many of these bacteria can promote plant growth by different means, including modification of plant hormonal balance and biocontrol. The group is currently divided into eight major subgroups in which these properties and many other ecophysiological traits are phylogenetically distributed.

Bioinformatics Analysis of the Complete Genome Sequence of the Mango Tree Pathogen Pseudomonas syringae pv. syringae UMAF0158 Reveals Traits Relevant to Virulence and Epiphytic Lifestyle.

The genome sequence of more than 100 Pseudomonas syringae strains has been sequenced to date; however only few of them have been fully assembled, including P. syringae pv. syringae B728a.

Cellulose production in Pseudomonas syringae pv. syringae: a compromise between epiphytic and pathogenic lifestyles.

Genome sequencing and annotation have revealed a putative cellulose biosynthetic operon in the strain Pseudomonas syringae pv. syringae UMAF0158, the causal agent of bacterial apical necrosis. Bioinformatics analyses and experimental methods were used to confirm the functionality of the cellulose biosynthetic operon.

Mangotoxin production of Pseudomonas syringae pv. syringae is regulated by MgoA.

Background: The antimetabolite mangotoxin is a key factor in virulence of Pseudomonas syringae pv. syringae strains which cause apical necrosis of mango trees. Previous studies showed that mangotoxin biosynthesis is governed by the mbo operon.

A Pseudomonas syringae diversity survey reveals a differentiated phylotype of the pathovar syringae associated with the mango host and mangotoxin production.

Pseudomonas syringae pv. syringae, the causal agent of bacterial apical necrosis (BAN) in mango crops, has been isolated in different mango-producing areas worldwide. An extensive collection of 87 P.

The mangotoxin biosynthetic operon (mbo) is specifically distributed within Pseudomonas syringae genomospecies 1 and was acquired only once during evolution.

Mangotoxin production was first described in Pseudomonas syringae pv. syringae strains. A phenotypic characterization of 94 P.

The mbo operon is specific and essential for biosynthesis of mangotoxin in Pseudomonas syringae.

Mangotoxin is an antimetabolite toxin produced by certain Pseudomonas syringae pv. syringae strains. This toxin is an oligopeptide that inhibits ornithine N-acetyl transferase, a key enzyme in the biosynthesis of ornithine and arginine.

Characterisation of the mgo operon in Pseudomonas syringae pv. syringae UMAF0158 that is required for mangotoxin production.

Background: Mangotoxin is an antimetabolite toxin that is produced by strains of Pseudomonas syringae pv. syringae; mangotoxin-producing strains are primarily isolated from mango tissues with symptoms of bacterial apical necrosis. The toxin is an oligopeptide that inhibits ornithine N-acetyl transferase (OAT), a key enzyme in the biosynthetic pathway of the essential amino acids ornithine and arginine.

Chemical and metabolic aspects of antimetabolite toxins produced by Pseudomonas syringae pathovars.

Pseudomonas syringae is a phytopathogenic bacterium present in a wide variety of host plants where it causes diseases with economic impact. The symptoms produced by Pseudomonas syringae include chlorosis and necrosis of plant tissues, which are caused, in part, by antimetabolite toxins. This category of toxins, which includes tabtoxin, phaseolotoxin and mangotoxin, is produced by different pathovars of Pseudomonas syringae.

Genes Involved in the Production of Antimetabolite Toxins by Pseudomonas syringae Pathovars.

Pseudomonas syringae is pathogenic in a wide variety of plants, causing diseases with economic impacts. Pseudomonas syringae pathovars produce several toxins that can function as virulence factors and contribute to disease symptoms. These virulence factors include antimetabolite toxins, such as tabtoxin, phaseolotoxin and mangotoxin, which target enzymes in the pathways of amino acid metabolism.

Contribution of mangotoxin to the virulence and epiphytic fitness of Pseudomonas syringae pv. syringae.

Mangotoxin is an antimetabolite toxin that inhibits ornithine acetyl transferase, a key enzyme in the biosynthetic pathway of ornithine and arginine and recently reported in strains of Pseudomonas syringae pv. syringae (Pss) isolated from mango. Since symptoms on mango tissues are very difficult to reproduce, in this study the role of mangotoxin in Pss virulence was addressed by analyzing the in planta growth and development of disease symptoms on tomato leaflets.

Copper Resistance in Pseudomonas syringae Strains Isolated from Mango Is Encoded Mainly by Plasmids.

ABSTRACT Bacterial apical necrosis of mango, elicited by Pseudomonas syringae pv. syringae, limits fruit production in southern Spain and Portugal. Examination of a collection of P.

A nonribosomal peptide synthetase gene (mgoA) of Pseudomonas syringae pv. syringae is involved in mangotoxin biosynthesis and is required for full virulence.

Pseudomonas syringae pv. syringae, which causes the bacterial apical necrosis of mango, produces the antimetabolite mangotoxin. We report here the cloning, sequencing, and identity analysis of a chromosomal region of 11.

The iturin and fengycin families of lipopeptides are key factors in antagonism of Bacillus subtilis toward Podosphaera fusca.

Podosphaera fusca is the main causal agent of cucurbit powdery mildew in Spain. Four Bacillus subtilis strains, UMAF6614, UMAF6619, UMAF6639, and UMAF8561, with proven ability to suppress the disease on melon in detached leaf and seedling assays, were subjected to further analyses to elucidate the mode of action involved in their biocontrol performance. Cell-free supernatants showed antifungal activities very close to those previously reported for vegetative cells.