Community standards and future opportunities for synthetic communities in plant-microbiota research.

Harnessing beneficial microorganisms is seen as a promising approach to enhance sustainable agriculture production. Synthetic communities (SynComs) are increasingly being used to study relevant microbial activities and interactions with the plant host. Yet, the lack of community standards limits the efficiency and progress in this important area of research.

Genetic Loci of Plant Pathogenic IPO 2222 Expressed in Contact with Weed-Host Bittersweet Nightshade ( L.) Plants.

, belonging to the Soft Rot , are aggressive necrotrophs, exhibiting both a wide geographic distribution and a wide host range that includes many angiosperm orders, both dicot and monocot plants, cultivated under all climatic conditions. Little is known about the infection strategies employs to infect hosts other than potato ( L.).

An iron fist in a velvet glove: The cooperation of a novel pyoverdine from Pseudomonas donghuensis P482 with 7-hydroxytropolone is pivotal for its antibacterial activity.

Pseudomonas donghuensis P482 exhibits broad antimicrobial activity against phytopathogens, including the soft rot bacteria of the Dickeya genus. Here, we report that under limited nutrient availability, the antibacterial activity of P. donghuensis P482 against Dickeya solani requires the reciprocal action of two iron scavengers: 7-hydroxytropolone (7-HT) and a newly characterized pyoverdine (PVD ) and is quenched in the iron-augmented environment.

Soft rot pathogen 3937 produces tailocins resembling the tails of P2.

Tailocins are nanomolecular machines with bactericidal activity. They are produced by bacteria to contribute to fitness in mixed communities, and hence, they play a critical role in their ecology in a variety of habitats. Here, we characterized the new tailocin produced by strain 3937, a well-characterized member of plant pathogenic Soft Rot (SRP).

Host-adaptive traits in the plant-colonizing Pseudomonas donghuensis P482 revealed by transcriptomic responses to exudates of tomato and maize.

Pseudomonads are metabolically flexible and can thrive on different plant hosts. However, the metabolic adaptations required for host promiscuity are unknown. Here, we addressed this knowledge gap by employing RNAseq and comparing transcriptomic responses of Pseudomonas donghuensis P482 to root exudates of two plant hosts: tomato and maize.

Spontaneous mutations in hlyD and tuf genes result in resistance of Dickeya solani IPO 2222 to phage ϕD5 but cause decreased bacterial fitness and virulence in planta.

Lytic bacteriophages able to infect and kill Dickeya spp. can be readily isolated from virtually all Dickeya spp. containing environments, yet little is known about the selective pressure those viruses exert on their hosts.

Crystal violet-based assay for the assessment of bacterial biofilm formation in medical tubing.

Crystal violet-based assay is widely used to evaluate the early stages of bacterial biofilm formation. Here, we modified it to study biofilm formation in medical tubing. While cost-effective and requiring no sophisticated equipment, our method provided quantitative and qualitative distinctions between the ability of four bacterial strains to colonize PVC catheters.

High-Quality Complete Genome Resource of Tomato Rhizosphere Strain P482, a Representative of a Species with Biocontrol Activity Against Plant Pathogens.

Strain P482 was isolated from a tomato rhizosphere and classified as . The species was first established in 2015 and currently consists of only four strains: P482, HYS, SVBP6, and 22G5. strains antagonize plant pathogens, including bacteria, fungi, and oomycetes, and, therefore, are of high interest regarding their biological control potential to combat plant diseases.

The Great Five-an artificial bacterial consortium with antagonistic activity towards Pectobacterium spp. and Dickeya spp.: formulation, shelf life, and the ability to prevent soft rot of potato in storage.

"The Great Five" (GF) is an artificial bacterial consortium developed to protect potato tubers from soft rot caused by Pectobacterium spp. and Dickeya spp. To investigate the commercialization potential of the GF, we developed liquid and powder formulations of the consortium and of each of the comprising strains (Serratia plymuthica strain A294, Enterobacter amnigenus strain A167, Rahnella aquatilis strain H145, Serratia rubidaea strain H440, and S.

Selection of reference genes for measuring the expression of aiiO in Ochrobactrum quorumnocens A44 using RT-qPCR.

Reverse transcription quantitative PCR (RT-qPCR), a method of choice for quantification of gene expression changes, requires stably expressed reference genes for normalization of data. So far, no reference genes were established for the Alphaproteobacteria of the genus Ochrobactrum. Here, we determined reference genes for gene expression studies in O.

Compatible Mixture of Bacterial Antagonists Developed to Protect Potato Tubers from Soft Rot Caused by spp. and spp.

Possibilities to protect potato tubers from rotting caused by Soft Rot Pectobacteriaceae (SRP) under disease favoring conditions were investigated using compatible mixtures of bacterial antagonists and tested with a newly developed stepwise efficacy-based screening protocol. Twenty-two bacterial antagonists were evaluated against a combination of five and strains representing species and subspecies most often associated with potato soft rot in Europe. To enable potential synergistic activity, the antagonists were initially tested against the combination of pathogens in 15 random mixtures containing up to 5 antagonists each.

Correction: Ochrobactrum quorumnocens sp. nov., a quorum quenching bacterium from the potato rhizosphere, and comparative genome analysis with related type strains.

[This corrects the article DOI: 10.1371/journal.pone.

Ochrobactrum quorumnocens sp. nov., a quorum quenching bacterium from the potato rhizosphere, and comparative genome analysis with related type strains.

Ochrobactrum spp. are ubiquitous bacteria attracting growing attention as important members of microbiomes of plants and nematodes and as a source of enzymes for biotechnology. Strain Ochrobactrum sp.

When Genome-Based Approach Meets the "Old but Good": Revealing Genes Involved in the Antibacterial Activity of Pseudomonas sp. P482 against Soft Rot Pathogens.

Dickeya solani and Pectobacterium carotovorum subsp. brasiliense are recently established species of bacterial plant pathogens causing black leg and soft rot of many vegetables and ornamental plants. Pseudomonas sp.

Exploring the genomic traits of fungus-feeding bacterial genus Collimonas.

Background: Collimonas is a genus belonging to the class of Betaproteobacteria and consists mostly of soil bacteria with the ability to exploit living fungi as food source (mycophagy). Collimonas strains differ in a range of activities, including swimming motility, quorum sensing, extracellular protease activity, siderophore production, and antimicrobial activities.

Results: In order to reveal ecological traits possibly related to Collimonas lifestyle and secondary metabolites production, we performed a comparative genomics analysis based on whole-genome sequencing of six strains representing 3 recognized species.

Genome Sequence of Pseudomonas sp. Strain P482, a Tomato Rhizosphere Isolate with Broad-Spectrum Antimicrobial Activity.

The tomato rhizosphere isolate Pseudomonas sp. strain P482 is a member of a diverse group of fluorescent pseudomonads. P482 produces a yet unidentified broad-spectrum antimicrobial compound(s), active inter alia (i.

Genome Sequence of Bacillus subtilis MB73/2, a Soil Isolate Inhibiting the Growth of Plant Pathogens Dickeya spp. and Rhizoctonia solani.

Bacillus subilis MB73/2 is a Gram-positive bacterium isolated in Poland from a meadow soil sample. When tested in vitro, the strain shows strong antagonism toward plant pathogens-the soft rot-causing bacteria Dickeya spp. and the crown rot fungus Rhizoctonia solani.

Colonization of potato rhizosphere by GFP-tagged Bacillus subtilis MB73/2, Pseudomonas sp. P482 and Ochrobactrum sp. A44 shown on large sections of roots using enrichment sample preparation and confocal laser scanning microscopy.

The ability to colonize the host plants' rhizospheres is a crucial feature to study in the case of Plant Growth Promoting Rhizobacteria (PGPRs) with potential agricultural applications. In this work, we have created GFP-tagged derivatives of three candidate PGPRs: Bacillus subtilis MB73/2, Pseudomonas sp. P482 and Ochrobactrum sp.

Inactivation of AHLs by Ochrobactrum sp. A44 depends on the activity of a novel class of AHL acylase.

The soil isolate Ochrobactrum sp. A44 inactivates N-acyl homoserine lactone (AHL) quorum sensing signal molecules and is capable of quenching the AHL-dependent virulence of Pectobacterium carotovorum in planta. To characterize this AHL inactivating activity, Ochrobactrum cell extracts were prepared and their capacity to degrade a broad range of AHLs was determined.

The influence of several factors on the efficiency of androgenesis in carrot.

The influence of cultivar, donor plant and culture procedure on the efficiency of androgenesis was studied in carrot anther culture. Experiments were carried out on five carrot cultivars: CxC 9900 F1, Lucky B F1, HCM, Beta III and Perfekcja, which were chosen because of their high carotene contents. Two procedures of anther culture were compared: (1) incubation in darkness for two weeks, followed by exposure to continuous light and transfer onto a fresh medium of the same composition; and (2) incubation in darkness until embryos appeared, without transfer onto a fresh medium.

Diversity of diploid androgenic Brussels sprout plants of R0 and R1 generations.

Androgenic Brussels sprout plants were produced by the use of anther culture from the donor cultivar 'Philemon F1'. A total of 96 plants obtained from 20 androgenic R0 genotypes assigned as diploids were evaluated both in the generative and vegetative stage, in respect of their morphological characters: mean plant height; leaf size, colour and waxiness; leaf blade shape, blistering and attitude; number of sprouts; as well as their self-incompatibility and fertility. Androgenic R0 plants derived from each of the 20 embryos were highly diversified and differed from the donor in one or more morphological traits in the vegetative stage.

Morphological diversity of androgenic carrot plants.

The aim of this study was to evaluate phenotypic variation of R0 androgenic plants obtained from four seed sources and donor plants by anther culture. Several morphological traits (leaf size, petiole length, leaf division, cortex colour) and the range of diversity were evaluated. There was large variation in all traits among the donor varieties.