Isolation and Characterization T4- and T7-Like Phages that Infect the Bacterial Plant Pathogen Agrobacterium tumefaciens

Abstract

In the rhizosphere, bacteria–phage interactions are likely to have important impacts on the ecology of microbial communities and microbe–plant interactions. To better understand the dynamics of Agrobacteria–phage interactions, we have isolated diverse bacteriophages which infect the bacterial plant pathogen, Agrobacterium tumefaciens. Here, we complete the genomic characterization of Agrobacterium tumefaciens phages Atu_ph04 and Atu_ph08. Atu_ph04—a T4-like phage belonging to the Myoviridae family—was isolated from waste water and has a 143,349 bp genome that encodes 223 predicted open reading frames (ORFs). Based on phylogenetic analysis and whole-genome alignments, Atu_ph04 is a member of a newly described T4 superfamily that contains other Rhizobiales-infecting phages. Atu_ph08, a member of the Podoviridae T7-like family, was isolated from waste water, has a 59,034 bp genome, and encodes 75 ORFs. Based on phylogenetic analysis and whole-genome alignments, Atu_ph08 may form a new T7 superfamily which includes Sinorhizobium phage PCB5 and Ochrobactrum phage POI1126. Atu_ph08 is predicted to have lysogenic activity, as we found evidence of an integrase and several transcriptional repressors with similarity to proteins in transducing phage P22. Together, this data suggests that Agrobacterium phages are diverse in morphology, genomic content, and lifestyle.

Shotgun Metagenomics evaluation of soil fertilization effect on the rhizosphere viral community of maize plants

“…Another important Podoviridae viruses are T7like viruses. They are lytic phages with short non-contractile tail and possess an icosahedral capsid and small genome (made of double stranded DNA) (Attai and Brown 2019;Pajunen et al 2002). PhiC31-like viruses are yet another important phages that infect a wide range of bacteria (Bacillus, Arthrobacter, Lactobacillus, Escherichia, Staphylococcus, Mycobacterium etc.).…”

Evaluation of Potential ARG Packaging by Two Environmental T7-Like Phage during Phage-Host Interaction

“…Phage host ranges were determined by examining plaque formation in bacterial lawns of 135 E. coli strains used as target cells as described previously [ 26 ]. The multiplicity of infection (MOI) was examined using appropriate susceptible E. coli strains cultured to early log phase growth and combined with phage (P:B = 10:1, 1:1, 0.1:1, 0.01:1, 0.001:1 and 0.0001:1) using standard protocols in triplicate.…”

Seeing the forest for the trees: Use of phages to treat bacterial tree diseases

“…Isolation of A. tumefaciens phages for biocontrol has only recently restarted. Several phages have had their genomes characterized, such as the unique flagellatropic phage 7-7-1, T4-like Atu_ph04, and the lysogenic T7-like Atu_ph08, and the myophage Milano, enabling further knowledge of A. tumefaciens phages and comparisons with other phages (Attai & Brown, 2019;Kropinski et al, 2012;Nittolo et al, 2019). Phages Atu_ph02 and Atu_ph03 caused significant reduction of tumour formation on potato discs compared to the non-phage-treated control, suggesting their potential use in phage cocktails (Attai et al, 2017).…”