title: Biological control of red rot in sugarcane by native pyoluteorin-producing Pseudomonas putida strain NH-50 under field conditions and its potential modes of action.
abstract: BACKGROUND
  Rhizobacteria have a good potential to suppress soilborne diseases, but their efficacy against sugarcane pests is rarely reported. Bacterial strains isolated from the rhizosphere of sugarcane were evaluated for their potential to suppress red rot disease on two susceptible varieties, Co-1148 and SPF-234, under field conditions. The strains were also characterised for the production of secondary metabolites associated with their antagonistic activity.
  
  
  RESULTS
  One out of four strains, the Pseudomonas putida strain NH-50 (EU627168), reduced disease severity by 44-60% in different field trials. This potent antagonistic strain produced pyoluteorin antibiotic, as confirmed by high-performance liquid chromatography (HPLC). The PltB gene involved in pyoluteorin synthesis was amplified from the P. putida strain NH-50 and sequenced. The extracellular metabolites and volatile and diffusible antibiotics secreted by the tested strains inhibited mycelial growth of Glomerella tucumensis (Speg.) Arx & E Mull in vitro by 7-55%.
  
  
  CONCLUSIONS
  The pyoluteorin-producing bacteria P. putida strain NH-50 significantly reduced disease severity on both sugarcane varieties, irrespective of fungal inoculation, i.e. either inoculated through stem or through soil. This strain also possesses other plant growth characteristics and can be used as a biopesticide for sugarcane crop.
authors.affiliation: National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan.
authors.forename: Muhammad N
authors.initials: MN
authors.lastname: Hassan
authors.forename: Shahid
authors.initials: S
authors.lastname: Afghan
authors.forename: Fauzia Y
authors.initials: FY
authors.lastname: Hafeez
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000378:metabolism*; D010572:Pest Control, Biological / Q000379:methods*; D010636:Phenols / Q000032:analysis / Q000378:metabolism*; D020081:Phyllachorales / Q000254:growth & development*; D010935:Plant Diseases / Q000382:microbiology*; D016958:Pseudomonas putida / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011758:Pyrroles / Q000032:analysis / Q000378:metabolism*; D058441:Rhizosphere; D031786:Saccharum / Q000382:microbiology*; D012988:Soil Microbiology
chemical_list: D000900:Anti-Bacterial Agents; D010636:Phenols; D011758:Pyrroles; C095503:pyoluteorin