GENETIC CONTROL OF FUSARIUM MYCOTOXINS TO ENHANCE FOOD SAFETY
Location: Bacterial Foodborne Pathogens & Mycology Research Unit
Title: Identifying and characterizing barley genes that protect against trichothecene mycotoxins
| Shin, Sanghyun - |
| Torres Acosta, Antonio - |
| Berthiller, Franz - |
| Schweiger, Wolfgang - |
| Adam, Gerhard - |
| Muehlbauer, Gary - |
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 10, 2011
Publication Date: August 10, 2011
Citation: Shin, S., Torres Acosta, A., Berthiller, F., Schweiger, W., Adam, G., Mccormick, S.P., Muehlbauer, G. 2011. Identifying and characterizing barley genes that protect against trichothecene mycotoxins. Meeting Abstract.
Fusarium head blight of wheat and barley, caused by the fungal pathogen Fusarium graminearum, is a major disease problem around the world. During infection, trichothecene mycotoxins are produced and act as virulence factors, resulting in reduced grain yield and quality. There are two types of trichothecenes: type B [e.g., deoxynivalenol (DON) and its derivatives and nivalenol (NIV)]; and type A [e.g., 4,15-diacetoxyscirpenol (DAS)]. Our primary goal is to study how wheat and barley cope with the accumulation of trichothecene mycotoxins. Previously, we conducted RNA profiling experiments and identified a large set of genes that respond to trichothecene accumulation. We also examined the fate of DON in barley found that a portion of DON is conjugated with a glucoside group to form the less toxic DON-3-O-glucoside (D3G). In addition, we showed that when DON and glutathione are mixed in vitro DON-glutathione conjugates are produced. Thus, we choose to focus our efforts on two classes of genes: UDP-glucosyltransferases and glutathione-S-transferases (GST). We cloned eight barley UDP-glucosyltransferase genes and tested them for tolerance to DON in yeast. We identified one UDP-glucosyltransferase gene that exhibited tolerance to DON and converted DON to D3G. We generated transgenic Arabidopsis over-expressing the barley UDP-glucosyltransferase and showed that these plants exhibited the ability to grow on media containing DON, DAS and NIV. DON feeding studies of the transgenic Arabidopsis plants showed that DON was converted to D3G. We also developed transgenic Arabidopsis over-expressing three GSTs and showed that these plants were tolerant to DON. These results showed that plants contain a variety of mechanisms to cope with trichothecene accumulation.