Bacteriophages vB_PsP_Sever, vB_PsP_Jiug, vB_PsP_Zapad and vB_PsP_Vostok Infecting Pseudomonas syringae: Genome Analysis and DTR Sequence Determination

Bacteriophages infecting Pseudomonas syringae represent promising candidates for the development of sustainable strategies to control bacterial plant diseases. In this study, four novel lytic bacteriophages—vB_PsP_Sever, vB_PsP_Jiug, vB_PsP_Vostok, and vB_PsP_Zapad—were isolated and characterised. All phages exhibited similar genome sizes (~40 kb) and gene content, with genome organisation closely resembling that of the model phage T7. Comparative genomic analysis revealed conserved modular architecture, including genes involved in virion structure, DNA packaging, host–cell lysis, and nucleotide metabolism, supporting their classification within the family Autotranscriptaviridae. Based on whole-genome nucleotide identity, phages vB_PsP_Jiug and vB_PsP_Sever were identified as representatives of novel species within the genera Pifdecavirus and Hennigervirus, respectively, whereas vB_PsP_Vostok and vB_PsP_Zapad were classified as new strains of previously described species. Restriction analysis and sequencing confirmed that all four phages utilise short direct terminal repeats (sDTRs) for genome packaging, consistent with T7-like phages. The lytic nature, genomic features, and diversity of the isolated phages highlight their potential for use as biocontrol agents against P. syringae. These findings expand the current knowledge of Pseudomonas phage diversity and provide a foundation for the development of phage-based approaches for plant disease management.