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ARS Home » Midwest Area » St. Paul, Minnesota » Cereal Disease Lab » Research » Publications at this Location » Publication #353358

Research Project: Fusarium Head Blight of Cereals: Pathogen Biology, Associated Phytobiome, and Host Resistance

Location: Cereal Disease Lab

Title: A SIX1 homolog of Fusarium oxysporum f.sp. cubense tropical race 4 contributes to virulence towards Cavendish banana

item WIDINUGRAHENI, SRI - University Of Amsterdam
item NINO-SANCHEZ, JONATAN - University Of Minnesota
item VAN DER DOES, HENRIETTE - University Of Amsterdam
item VAN DAM, PETER - University Of Amsterdam
item GARCIA-BASTIDAS, FERNANDO - Wageningen University
item SUBANDIYAH, SITI - Gadjah Mada University
item MEIJER, HAROLD - Wageningen University
item Kistler, Harold
item KEMA, GERT - Wageningen University
item REP, MARTIJN - University Of Amsterdam

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/3/2018
Publication Date: 10/22/2018
Citation: Widinugraheni, S., Nino-Sanchez, J., van der Does, H.C., van Dam, P., Garcia-Bastidas, F.A., Subandiyah, S., Meijer, H.J.G., Kistler, H.C., Kema, G.H.J., Rep, M. 2018. A SIX1 homolog of Fusarium oxysporum f.sp. cubense tropical race 4 contributes to virulence towards Cavendish banana. PLoS One.

Interpretive Summary: Panama disease of banana is one of the leading constraints to the banana export trade. The recent emergence of a new strain of the fungal pathogen called tropical race 4 (TR4) has endangered production of the highly desirable banana variety "Cavendish" in southeastern Asia, Africa and Australia. By comparing TR4 with older races of the pathogen, USDA scientists collaborating with scientists at the University of Amsterdam, were able to predict genes in TR4 that could lead to virulence toward Cavendish. Mutations were made in candidate genes in the fungus, confirming the involvement of one such gene in virulence. This knowledge can be exploited for screening for varieties of bananas naturally resistant to TR4 or by developing transgenic Cavendish that mitigate the harmful effects of the TR4 virulence factor.

Technical Abstract: The fungus Fusarium oxysporum f.sp. cubense (Focub) causes Panama disease of banana. Focub strains are divided into races according to their host specificity, but which virulence factors underlie these interactions is currently unknown. In the F. oxysporum f.sp. lycopersici (Fol)-tomato system, small fungal secreted proteins called Six proteins were identified in the xylem sap of infected plants. The Fol Six1 protein contributes to virulence and has an avirulence function by activating the I-3 immune receptor of tomato. In the Focub tropical race 4 (TR4) genome three SIX1 homologs have been identified: SIX1a, b and c. In this study, we analyzed the role of FocubSIX1a in pathogenicity since this homolog is present in all Focub races. A deletion mutant of the SIX1a gene from Focub TR4 strain II5 was generated (Focub deltaSIX1a). Mutants were tested in infection assays and were found to be compromised in their virulence. Complementation of the Focub deltaSIX1a strain with the FocubSIX1a gene restored virulence to wild type levels. We conclude that FocubSIX1a is required for full virulence of Focub TR4 towards Cavendish banana.