title: Antagonistic bacterium Bacillus amyloliquefaciens induces resistance and controls the bacterial wilt of tomato.
abstract: BACKGROUND
  Bacterial wilt caused by Ralstonia solanacearum (RS) is a serious threat for agricultural production. In this study, Bacillus amyloliquefaciens strains CM-2 and T-5 antagonistic to RS were used to create bioorganic fertilisers to control tomato wilt under greenhouse conditions. The possible mechanism of resistance inducement by the antagonistic bacteria was also evaluated.
  
  
  RESULTS
  The application of bioorganic fertilisers significantly reduced incidences of tomato wilt (by 63-74%), promoted plant growth and significantly reduced the RS populations in rhizosphere compared with the control. Both strains CM-2 and T-5 applied with bioorganic fertilisers survived well in the tomato rhizosphere. Tomato seedlings treated with cell suspension of T-5 followed by challenge inoculation with RS increased the activities of polyphenol oxidase, phenylalanine ammonia lyase and peroxidase compared with the untreated control. Furthermore, the expressions of the marker genes responsible for synthesis of phytohormones salicylic acid, ethylene and jasmonic acid in seedlings treated with T-5 in response to inoculated pathogen were significantly higher.
  
  
  CONCLUSIONS
  This study suggests that strains CM-2 and T-5 containing bioorganic fertilisers effectively control tomato wilt. Increased enzyme activities and expression of defence genes in plants indicated that the antagonistic bacteria induced plant resistance, which was the potential biocontrol mechanism of tomato wilt.
authors.affiliation: Jiangsu Provincial Key Lab of Organic Solid Waste Utilisation, Nanjing Agricultural University, Nanjing, China.
authors.forename: Shiyong
authors.initials: S
authors.lastname: Tan
authors.forename: Yue
authors.initials: Y
authors.lastname: Dong
authors.forename: Hanpeng
authors.initials: H
authors.lastname: Liao
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Huang
authors.forename: Song
authors.initials: S
authors.lastname: Song
authors.forename: Yangchun
authors.initials: Y
authors.lastname: Xu
authors.forename: Qirong
authors.initials: Q
authors.lastname: Shen
mesh_terms: D059827:Agricultural Inoculants / Q000502:physiology*; D000898:Antibiosis; D001407:Bacillus / Q000502:physiology*; D018551:Solanum lycopersicum / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology* / Q000517:prevention & control; D043368:Ralstonia solanacearum / Q000502:physiology*
keywords: Bacillus amyloliquefaciens; RT-PCR; Ralstonia solanacearum; bioorganic fertiliser; defence enzyme; tomato