title: Involvement of phenazines and lipopeptides in interactions between Pseudomonas species and Sclerotium rolfsii, causal agent of stem rot disease on groundnut.
abstract: OBJECTIVE
  To determine the role of phenazines (PHZ) and lipopeptide surfactants (LPs) produced by Pseudomonas in suppression of stem rot disease of groundnut, caused by the fungal pathogen Sclerotium rolfsii.
  
  
  RESULTS
  In vitro assays showed that PHZ-producing Pseudomonas chlororaphis strain Phz24 significantly inhibited hyphal growth of S. rolfsii and suppressed stem rot disease of groundnut under field conditions. Biosynthesis and regulatory mutants of Phz24 deficient in PHZ production were less effective in pathogen suppression. Pseudomonas strains SS101, SBW25 and 267, producing viscosin or putisolvin-like LPs, only marginally inhibited hyphal growth of S. rolfsii and did not suppress stem rot disease. In contrast, Pseudomonas strain SH-C52, producing the chlorinated LP thanamycin, inhibited hyphal growth of S. rolfsii and significantly reduced stem rot disease of groundnut in nethouse and field experiments, whereas its thanamycin-deficient mutant was less effective.
  
  
  CONCLUSIONS
  Phenazines and specific lipopeptides play an important role in suppression of stem rot disease of groundnut by root-colonizing Pseudomonas strains.
  
  
  CONCLUSIONS
  Pseudomonas strains Phz24 and SH-C52 showed significant control of stem rot disease. Treatment of seeds or soil with these strains provides a promising supplementary strategy to control stem rot disease of groundnut.
authors: Laboratory of Phytopathology, Wageningen University, Wageningen, The Netherlands.
authors: C N
authors: CN
authors: Le
authors: M
authors: M
authors: Kruijt
authors: J M
authors: JM
authors: Raaijmakers
mesh_terms: D000898:Antibiosis; D010367:Arachis / Q000382:microbiology*; D001203:Ascomycota / Q000502:physiology*; D001426:Bacterial Proteins / Q000378:metabolism*; D055666:Lipopeptides / Q000378:metabolism*; D010619:Phenazines / Q000378:metabolism*; D010935:Plant Diseases / Q000382:microbiology; D018517:Plant Roots / Q000382:microbiology; D018547:Plant Stems / Q000382:microbiology; D011549:Pseudomonas / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D012639:Seeds / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D055666:Lipopeptides; D010619:Phenazines; C000607810:thanamycin