Project description:Fusarium graminearum is the major causal agent of Fusarium head blight (FHB) in North America and other regions of the world. The pathogen causes direct yield losses and produces various types of trichothecenes mycotoxins [Deoxynivalenol (DON) and its acetylated forms (3-acetyl-4-deoxynivalenol=3ADON and 15-acetyl-4-deoxvevalenol=15ADON), nivalenol (NIV). Recent studies indicated that 3ADON-type isolates were significantly increased in North America and China in recent years and appears to be more aggressive based on growth rate, disease severity on different cultivars, and DON production in vitro. Thus the overall objective of this this study was to understand the molecular mechanisms that make 3ADON- and 15ADON-type populations different during infection using a susceptible cultivar, and to compare the transcriptomes of the 3ADON- and 15ADON-type populations in vitro and in planta using the RNA-seq approach as well as to identify the expression differences of candidate genes related to aggressiveness and DON production.
Project description:The plant pathogenic fungus Fusarium graminearum (Fgr) creates economic and health risks in cereals agriculture. Fgr causes head blight (or scab) of wheat and stalk rot of corn, reducing yield, degrading grain quality and polluting downstream food products with mycotoxins. Fungal plant pathogens must secrete proteases to access nutrition and to breakdown the structural protein component of the plant cell wall. Research into the proteolytic activity of Fgr is hindered by the complex nature of the suite of proteases secreted. We used a systems biology approach comprising genome analysis, transcriptomics and label-free quantitative proteomics to characterise the peptidases deployed by Fgr during growth. A combined analysis of published microarray transcriptome datasets revealed seven transcriptional groupings of peptidases based on in vitro growth, in planta growth, and sporulation behaviours. An orbitrap MS/MS proteomics technique defined the extracellular proteases secreted by Fusarium graminearum.