Submitted to: National Fusarium Head Blight Forum Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 11/30/2001
Publication Date: 12/1/2001
Citation: Manoharan, M., Dahleen, L.S., Hohn, T., Mc Cormick, S.P., Alexander, N.J., Shwarz, P., Horsley, R.D. 2001. Transformation of a commercial barley cultivar with genes for resistance to fusarium head blight. National Fusarium Head Blight Forum Proceedings, p. 21. Interpretive Summary:
Technical Abstract: Fusarium head blight, incited primarily by Fusarium graminearum, has caused devastating losses to barley since the 1990's Production of the mycotoxin deoxynivalenol (DON) by F. graminearum is harmful to humans and livestock. Expressing certain anti-toxin genes such as TR/101 and PDR5 could improve resistance to fungal infection and reduce DON levels. TR/101 encodes a 3-OH trichothecene acetyltransferase that converts DON to a less toxic acetylated form. PDR5, an ATP-binding cassette, acts as an efflux transporter, shunting DON across the plasma membrane from the interior of the cell. We have transformed the commercial malting barley cultivar Conlon with these genes to reduce DON levels in infected grain. Ten-day old calli derived from immature embryos were co-bombarded with the herbicide-resistance gene bar as the selectable marker. Putative transgenic plants were confirmed by Southern analysis. A total of seven independent events with TR/101 and six with PDR5 were recovered. Northern analysis indicated the expression of PDR5. Expression of TR/101 was confirmed by detecting acetyltransferase activity in seeds of the transgenic plants. T2 lines of three events with TR/101 and two events with PDR5 were field tested for disease and toxin level. Both genes appeared to reduce FHB infection and PDR5 also may reduce DON accumulation.