Cyanide production by Pseudomonas fluorescens helps suppress black root rot of tobacco under gnotobiotic conditions

摘要: Pseudomonas fluorescens CHA0 suppresses black root rot of tobacco, a disease caused by the fungus Thielaviopsis basicola. Strain excretes several metabolites with antifungal properties. The importance one such metabolite, hydrogen cyanide, was tested in gnotobiotic system containing an artificial, iron-rich soil. A cyanidenegative (hcn) mutant, CHA5, constructed gene replacement technique, protected tobacco plant less effectively than did wild-type CHA0. Complementation strain CHA5 cloned hcn+ genes restored strain's ability to suppress disease. An artificial transposon carrying (Tnhcn) and inserted into genome another P.fluorescens strain, P3, which naturally does not produce cyanide gives poor protection. P3::Tnhcn derivative synthesized exhibited improved All bacterial strains colonized roots similarly influence significantly survival T.basicola We conclude that is important but only factor involved suppression rot.