title: Antibacterial activity of two chitosan solutions and their effect on rice bacterial leaf blight and leaf streak.
abstract: BACKGROUND
  Bacterial leaf blight and leaf streak are the two most damaging bacterial diseases of rice. However, few bactericidal chemicals are available for controlling both diseases. The antibacterial properties of two kinds of chitosan with different molecular weights and degrees of N-deacetylation and their effect on rice bacterial leaf blight and leaf streak were evaluated.
  
  
  RESULTS
  Results showed that the two kinds of chitosan solution possess a strong antibacterial activity against both rice bacterial pathogens and significantly reduced disease incidence and severity by comparison with the control under greenhouse conditions. However, the interaction between chitosan and rice pathogens was affected by the type and concentration of chitosan, the bacterial species and the contact time between chitosan and bacteria. The direct antibacterial activity of chitosan may be attributed to both membrane lysis and the destruction of biofilm. In addition, both chitosan solutions significantly increased the activities of phenylalanine ammonia lyase, peroxidase and polyphenol oxidase in rice seedlings following inoculation of two rice pathogens by comparison with the control.
  
  
  CONCLUSIONS
  The role of chitosan in protection of rice against bacterial pathogens has been shown to involve direct antibacterial activity and indirect induced resistance.
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, China. libin0571@zju.edu.cn
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Baoping
authors.initials: B
authors.lastname: Liu
authors.forename: Changlin
authors.initials: C
authors.lastname: Shan
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ibrahim
authors.forename: Yihan
authors.initials: Y
authors.lastname: Lou
authors.forename: Yangli
authors.initials: Y
authors.lastname: Wang
authors.forename: Guanlin
authors.initials: G
authors.lastname: Xie
authors.forename: Hong-ye
authors.initials: HY
authors.lastname: Li
authors.forename: Guochang
authors.initials: G
authors.lastname: Sun
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D048271:Chitosan / Q000494:pharmacology*; D012275:Oryza / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D048271:Chitosan