Genome Sequence of a Jumbo Bacteriophage That Infects the Kiwifruit Phytopathogen Pseudomonas syringae pv. actinidiae

Wojtus, Joanna K.; Frampton, Rebekah A.; Warring, Suzanne L.; Hendrickson, Heather; Fineran, Peter C.

doi:10.1128/mra.00224-19

Cited by 16 publications

(17 citation statements)

References 28 publications

(27 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One of the most numerous Psa phage collections was gathered in New Zealand in 2014 [ 16 ] with 258 phages active against Psa, of which 24 were observed by TEM, revealing myovirus-, podovirus- and siphovirus-like morphologies. Among these phages, myovirus phiPsa21 showed an unusually large genome and was later recognized as a jumbo phage [ 59 ], containing genes possibly associated with the formation of a nucleoid-like structure in the host cell. In the same year, Di Lallo [ 15 ] isolated and sequenced two Psa phages: phiPSA1 and phiPSA2.…”

Section: Discussionmentioning

confidence: 99%

Molecular Characterization and Taxonomic Assignment of Three Phage Isolates from a Collection Infecting Pseudomonas syringae pv. actinidiae and P. syringae pv. phaseolicola from Northern Italy

Martino

Holtappels

Vallino

et al. 2021

Viruses

View full text Add to dashboard Cite

Bacterial kiwifruit vine disease (Pseudomonas syringae pv. actinidiae, Psa) and halo blight of bean (P. syringae pv. phaseolicola, Pph) are routinely treated with copper, leading to environmental pollution and bacterial copper resistance. An alternative sustainable control method could be based on bacteriophages, as phage biocontrol offers high specificity and does not result in the spread of toxic residues into the environment or the food chain. In this research, specific phages suitable for phage-based biocontrol strategies effective against Psa and Pph were isolated and characterized. In total, sixteen lytic Pph phage isolates and seven lytic Psa phage isolates were isolated from soil in Piedmont and Veneto in northern Italy. Genome characterization of fifteen selected phages revealed that the isolated Pph phages were highly similar and could be considered as isolates of a novel species, whereas the isolated Psa phages grouped into four distinct clades, two of which represent putative novel species. No lysogeny-, virulence- or toxin-related genes were found in four phages, making them suitable for potential biocontrol purposes. A partial biological characterization including a host range analysis was performed on a representative subset of these isolates. This analysis was a prerequisite to assess their efficacy in greenhouse and in field trials, using different delivery strategies.

show abstract

Section: Discussionmentioning

confidence: 99%

Molecular Characterization and Taxonomic Assignment of Three Phage Isolates from a Collection Infecting Pseudomonas syringae pv. actinidiae and P. syringae pv. phaseolicola from Northern Italy

Martino

Holtappels

Vallino

et al. 2021

Viruses

View full text Add to dashboard Cite

show abstract

“…The genome of jumbo phage AR9 infecting B. subtilis , a close relative of the PBS2 phage, was sequenced and shown to contain genes orthologous to the RNAP genes of phiKZ-like phages [ 18 ], suggesting that the PBS2 RNAP purified a long time ago [ 35 , 36 ] in fact belongs to this new group of non-canonical jumbo phage RNAPs. At the time of this writing, several dozens of jumbo phages encoding distant homologs of the β′ and β subunits are known [ 18 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 ]. They infect diverse bacterial hosts including members of Pseudomonas , Salmonella , Yersinia , Erwinia , Vibrio , Ralstonia , Bacillus , Aeromonas , Serratia , Klebsiella , Escherichia , and other genera [ 18 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , …”

Section: Jumbo Phages Encoding Rna Polymerases and Their Featuresmentioning

confidence: 99%

Multisubunit RNA Polymerases of Jumbo Bacteriophages

Sokolova

Misovetc

Severinov

2020

Viruses

View full text Add to dashboard Cite

Prokaryotic viruses with DNA genome longer than 200 kb are collectively referred to as “jumbo phages”. Some representatives of this phylogenetically diverse group encode two DNA-dependent RNA polymerases (RNAPs)—a virion RNAP and a non-virion RNAP. In contrast to most other phage-encoded RNAPs, the jumbo phage RNAPs are multisubunit enzymes related to RNAPs of cellular organisms. Unlike all previously characterized multisubunit enzymes, jumbo phage RNAPs lack the universally conserved alpha subunits required for enzyme assembly. The mechanism of promoter recognition is also different from those used by cellular enzymes. For example, the AR9 phage non-virion RNAP requires uracils in its promoter and is able to initiate promoter-specific transcription from single-stranded DNA. Jumbo phages encoding multisubunit RNAPs likely have a common ancestor allowing making them a separate subgroup within the very diverse group of jumbo phages. In this review, we describe transcriptional strategies used by RNAP-encoding jumbo phages and describe the properties of characterized jumbo phage RNAPs.

show abstract

“…Phages against P. syringae pv. actinidiae have been isolated in Italy [ 26 ], New Zealand [ 27 , 28 , 29 ], Korea [ 30 ] and China [ 31 ]. All these phages have been subjected to general characterization, showing the potential to control Psa in in vitro conditions.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Bacteriophages against Pseudomonas Syringae pv. Actinidiae with Potential Use as Natural Antimicrobials in Kiwifruit Plants

et al. 2020

View full text Add to dashboard Cite

Pseudomonas syringae pv. actinidiae (Psa) is the causal agent of a bacterial canker in kiwifruit plants and has caused economic losses worldwide. Currently, the primary strategies to control this pathogen include the use of copper-based compounds and even antibiotics. However, the emergence of isolates of Psa that are resistant to these agrochemicals has raised the need for new alternatives to control this pathogen. Bacteriophages have been proposed as an alternative to control bacterial infections in agriculture, including Psa. Here, we show the isolation and characterization of 13 phages with the potential to control Psa infections in kiwifruit plants. The phages were characterized according to their host range and restriction fragment length polymorphism (RFLP) pattern. Four phages were selected according to their lytic effect on the bacteria and their tolerance to different environmental conditions of pH (4–7), temperature (4–37 °C), and solar radiation exposure (30 and 60 min). The selected phages (CHF1, CHF7, CHF19, and CHF21) were sequenced, revealing a high identity with the podophage of Psa phiPSA2. In vitro assays with kiwifruit leaf samples demonstrated that the mixture of phages reduced the Psa bacterial load within three hours post-application and was able to reduce the damage index in 50% of cases. Similarly, assays with kiwifruit plants maintained in greenhouse conditions showed that these phages were able to reduce the Psa bacterial load in more than 50% of cases and produced a significant decrease in the damage index of treated plants after 30 days. Finally, none of the selected phages were able to infect the other bacteria present in the natural microbiota of kiwifruit plants. These results show that bacteriophages are an attractive alternative to control Psa infections in kiwifruit plants.

show abstract

Genome Sequence of a Jumbo Bacteriophage That Infects the Kiwifruit Phytopathogen Pseudomonas syringae pv. actinidiae

Abstract: Bacteriophage ϕPsa21 is a potential biocontrol agent that infects the kiwifruit phytopathogen Pseudomonas syringae pv. actinidiae. ϕPsa21 is a “jumbo” phage with a genome of ∼305 kb.

Cited by 16 publications

References 28 publications

Molecular Characterization and Taxonomic Assignment of Three Phage Isolates from a Collection Infecting Pseudomonas syringae pv. actinidiae and P. syringae pv. phaseolicola from Northern Italy

Molecular Characterization and Taxonomic Assignment of Three Phage Isolates from a Collection Infecting Pseudomonas syringae pv. actinidiae and P. syringae pv. phaseolicola from Northern Italy

Multisubunit RNA Polymerases of Jumbo Bacteriophages

Characterization of Bacteriophages against Pseudomonas Syringae pv. Actinidiae with Potential Use as Natural Antimicrobials in Kiwifruit Plants

Contact Info

Product

Resources

About