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ARS Home » Midwest Area » St. Paul, Minnesota » Cereal Disease Lab » Research » Publications at this Location » Publication #300624
Title: EBR1 genomic expansion and its role in virulence of Fusarium species

Author
item JONKERS, WILFRIED - University Of Minnesota
item XAYAMONGKHON, HENRY - University Of Minnesota
item HAAS, MATTHEW - University Of Minnesota
item OLIVAIN, CHANTAL - Institut National De La Recherche Agronomique (INRA)
item VAN DER DOES, H. CHARLOTTE - Free University Of Amsterdam
item Broz, Karen
item REP, MARTIJN - Free University Of Amsterdam
item ALABOUVETTE, CLAUDE - Institut National De La Recherche Agronomique (INRA)
item STEINBERG, CHRISTIAN - Institut National De La Recherche Agronomique (INRA)
item Kistler, Harold

Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2013
Publication Date: 12/1/2013
Citation: Jonkers, W., Xayamongkhon, H., Haas, M., Olivain, C., Van der Does, H., Broz, K.L., Rep, M., Alabouvette, C., Steinberg, C., Kistler, H.C. 2014. EBR1 genomic expansion and its role in virulence of Fusarium species. Environmental Microbiology. Available: http://www.ncbi.nlm.nih.gov/pubmed/24237614.

Interpretive Summary: Fusarium oxysporum is a fungus responsible for billions of dollars in losses to agricultural plants. We have conducted research aimed at understanding how genes in this harmful pathogen are turned on and off, especially if this regulation controls the ability of the fungus to cause disease or to allow toxins to be produced. Using a genomics approach, we identified a gene in the fungus that allows for toxin accumulation and disease causing ability. Factors which regulate this gene also control expression of important traits that could potentially be exploited for disease control measures. These disease management strategies may involve disruption of vital fungal developmental pathways. The primary users of the research in this publication will be other scientists engaged in research to improve disease management on small grain crops.

Technical Abstract: Genome sequencing of Fusarium oxysporum revealed that pathogenic forms of this fungus harbor supernumerary chromosomes with a wide variety of genes, many of which likely encode traits required for pathogenicity or niche specialization. Specific transcription factor (TF) gene families are expanded on these chromosomes including the EBR1 family (Enhanced Branching). The significance of the EBR1 family expansion on supernumerary chromosomes and whether EBR1 paralogs are functional is currently unknown. EBR1 is found as a single copy in Fusarium graminearum and other fungi but as multiple paralogs in pathogenic Fusarium oxysporum strains. These paralogs exhibit sequence and copy number variation among different host-specific strains and even between more closely related strains. Relative expression of the EBR1 paralogs depends on growth conditions and on the presence of the single EBR1 gene in the core genome. Deletion of EBR1 in the core genome in different F. oxysporum strains resulted in impaired growth, reduced pathogenicity and slightly reduced biocontrol capacities. To identify genes regulated by EBR1, the transcriptomes of wild type and 'ebr1 strains were compared for both F. oxysporum and F. graminearum. These studies showed that in both species, EBR1 regulates genes involved in general metabolism as well as virulence.