Complete genome sequences of two novel Ralstonia jumbo phages isolated from leaf litter compost

Area of Science:

• Microbiology
• Virology
• Plant Pathology

Background:

• Ralstonia pseudosolanacearum causes significant bacterial wilt disease in plants.
• Bacteriophages are viruses that infect bacteria and are being explored for biocontrol applications.

Purpose of the Study:

• To isolate and characterize novel bacteriophages targeting Ralstonia pseudosolanacearum.
• To assess the potential of these phages as biocontrol agents against bacterial wilt.

Main Methods:

• Isolation of phages from leaf litter compost using Ralstonia pseudosolanacearum as the host.
• Whole-genome sequencing and comparative genomic analysis of isolated phages.
• Evaluation of phage FLC4-3B for its ability to suppress bacterial wilt in tomato plants.

Main Results:

• Two jumbo phages, FLC1-1B (290,008 bp) and FLC4-3B (291,257 bp), were isolated and sequenced.
• These phages showed low similarity to known jumbo phages, suggesting they represent a new genus in the order Caudoviricetes.
• Phage FLC4-3B demonstrated efficacy in suppressing bacterial wilt disease in tomato plants.

Conclusions:

• FLC1-1B and FLC4-3B are novel jumbo phages belonging to a new genus within Caudoviricetes.
• Phage FLC4-3B holds promise as a biocontrol agent for managing Ralstonia pseudosolanacearum infections and bacterial wilt disease.