Submitted to: North American Barley Research Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 20, 1999
Publication Date: June 22, 1999
Citation: Dahleen, L.S., Mc Cormick, S.P. 1999. Trichothecene toxin effects on barley callus and seedling growth. North American Barley Research Workshop Proceedings, p. 56. Technical Abstract: Fusarium head blight (FHB) has caused devastating losses to barley growers since 1993. A major component of these losses has been the formation of trichothecene toxins such as deoxynivalenol (DON) by the Fusarium. Genetic transformation of barley with genes that chemically inactivate or transport the toxins out of cells has potential for reducing DON levels. The ability to directly select for callus cells transformed with these genes would simplify production of transgenic plants and avoid the introduction of a second selectable gene. The objective of this study was to determine the effects of DON and the related toxin diacetoxyscirpenol (DAS) on barley callus growth and seedling germination, root and shoot growth. Morex calli were placed on media containing 0, 1, 5, or 10 mg/L DON or DAS, and fresh weights were measured after four and eight weeks. The effects of the toxins on callus growth were small. Although statistically significant differences were seen at the higher toxin levels after eight weeks, the differences were not large enough for selection between toxin resistant and toxin susceptible calli. Seed were placed on the same media and toxin levels as used for callus growth, and germination rates were measured. Root and shoot length of germinated seedlings were measured for up to nine days after germination. Neither toxin had an effect on seed germination. DON at 5 and 10 mg/L significantly reduced root growth by day 7, and 10 mg/L significantly reduced shoot growth by day 4. The effects of DAS were greater, with all toxin levels significantly reducing root growth by day 2 and shoot growth by day 4. The results indicate that DAS may be usable for screening progeny of transgenic plants for segregation of anti-toxin genes.