title: The filamentous phage ϕRSS1 enhances virulence of phytopathogenic Ralstonia solanacearum on tomato.
abstract: Ralstonia solanacearum is the causative agent of bacterial wilt in many important crops. ϕRSS1 is a filamentous phage that infects R. solanacearum strains. Upon infection, it alters the physiological state and the behavior of host cells. Here, we show that R. solanacearum infected by ϕRSS1 becomes more virulent on host plants. Some virulence and pathogenicity factors, such as extracellular polysaccharide (EPS) synthesis and twitching motility, increased in the bacterial host cells infected with ϕRSS1, resulting in early wilting. Tomato plants inoculated with ϕRSS1-infected bacteria wilted 2 to 3 days earlier than those inoculated with wild-type bacteria. Infection with ϕRSS1 induced early expression of phcA, the global virulence regulator. phcA expression was detected in ϕRSS1-infected cells at cell density as low as 10(4) CFU/ml. Filamentous phages are assembled on the host cell surface and many phage particles accumulate on the cell surface. These surface-associated phage particles (phage proteins) may change the cell surface nature (hydrophobicity) to give high local cell densities. ϕRSS1 infection also enhanced PilA and type IV pilin production, resulting in increased twitching motility.
authors.affiliation: Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8530, Japan.
authors.forename: Hardian S
authors.initials: HS
authors.lastname: Addy
authors.forename: Ahmed
authors.initials: A
authors.lastname: Askora
authors.forename: Takeru
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Makoto
authors.initials: M
authors.lastname: Fujie
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamada
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001435:Bacteriophages / Q000502:physiology*; D002480:Cellulase / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics; D036781:Fimbriae Proteins / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D054884:Host-Pathogen Interactions; D018551:Solanum lycopersicum / Q000382:microbiology*; D008565:Membrane Proteins / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology*; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D043368:Ralstonia solanacearum / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology / Q000821:virology; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics; D014764:Viral Proteins / Q000378:metabolism; D014774:Virulence; D037521:Virulence Factors
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D008565:Membrane Proteins; C082933:PhcA protein, Ralstonia solanacearum; D011135:Polysaccharides, Bacterial; D014157:Transcription Factors; D014764:Viral Proteins; D037521:Virulence Factors; D036781:Fimbriae Proteins; D002480:Cellulase