Skip to main content
ARS Home » Northeast Area » Washington, D.C. » National Arboretum » Floral and Nursery Plants Research » Research » Publications at this Location » Publication #358318
Research Project: Detection, Identification, and Characterization of New and Emerging Viral and Bacterial Diseases of Ornamental Plants

Location: Floral and Nursery Plants Research

Title: Molecular and biological characterization of Ralstonia phage RsoM1USA, a new species of P2Virus, isolated in the USA

Author
item ADDY, HARDIAN - University Of Jember
item EBRAHIM, ABDELMONIM ALI - Minia University
item Huang, Qi

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2019
Publication Date: 2/19/2019
Citation: Addy, H.S., Ebrahim, A., Huang, Q. 2019. Molecular and biological characterization of Ralstonia phage RsoM1USA, a new species of P2Virus, isolated in the USA. Frontiers in Microbiology. 10:267. https://doi.org/10.3389/fmicb.2019.00267.
DOI: https://doi.org/10.3389/fmicb.2019.00267

Interpretive Summary: A bacterium called Ralstonia causes a serious brown rot disease in potato and is considered a quarantine pest in the U.S., Canada, and Europe. ARS scientists in Beltsville, MD found a virus in the soil of a tomato field in Florida, USA that can kill the bacterium. They purified and characterized the virus, and determined its DNA and protein sequences, as well as its potential to control the bacterium. This study is important to better understand the virus and to develop effective control of this destructive bacterium.

Technical Abstract: The first Ralstonia solanacearum-infecting bacteriophage, designated RsoM1USA, from USA was isolated from soil of a tomato field in Florida. Electron Microscopy revealed that phage RsoM1USA is member of the family Myoviridae with an icosahedral head of about 66 nm in diameter, a contractile tail of about 152 nm in length, and a long “neck”. Phage RsoM1USA has a relatively wide host range infecting 13 of the 30 tested R. solanacearum strains collected worldwide and completed its infection cycle 180 minutes post infection with a burst size of about 56 particles per cell. Phage RsoM1USA has a genome of 39,309 nucleotides containing 58 open reading frames (ORFs) and is closely related to Ralstonia phage RSA1. The genomic organization of phage RsoM1USA is also similar to that of phage RSA1, but their integrases share no sequence homology. In addition, we determined that the integration of phage RsoM1USA into its susceptible R. solanacearum strain K60 is mediated by 45-bases of the 3’ portion of the threonine tRNA (TGT), not arginine tRNA (CCG) as reported for phage RSA1, confirming that the two phages use different mechanism for integration. Our proteomic analysis of the purified virions supported the annotation of the main structural proteins. Infection of a susceptible R. solanacearum strain RUN302 by phage RsoM1USA resulted in significantly reduced growth of the bacterium in vitro, but not virulence in tomato plants, as compared to its uninfected wild type RUN302 strain. Due to its differences from phage RSA1, phage RsoM1USA should be considered the type phage of a new species with a proposed species name of Ralstonia virus RsoM1USA.