Investigating the mechanisms underpinning bacterium-mediated control of FHB disease

Pseudomonads, including P.fluorescens strain MKB 158, can inhibit the development of Fusarium seedling blight disease on wheat and barley. Application of (his and other pseudomonads as head sprays inhibits the development of Fusarium head blight disease (FHB) disease on wheat and barley under both field and glasshouse conditions. P.fluorescens strains MKB 158 and MKB 249 also reduced DON contamination of grain tinder field conditions. Evidence suggests that P.fluorescens does not directly inhibit the growth of Fusarium, but that it potentiates host resistance against this disease. Transcriptome profiling identified barley genes differentially expressed as early events in (a) bacterium-induced resistance to seedling blight and (b) heads following P.fluorescens and Fusarium culmorum co-inoculation. Bacterium-potentiated resistance to Fusarium affects the transcription of many genes that are involved in diverse processes, including cell rescue and defence, metabolism, cell cycle and DNA replication and signalling.