Poster # 303

Guixia Hao ¹, Gabdiel Yulfo-Soto ^1,2, Hui Chen ³, Guihua Bai ^3,4, Harold N. Trick ⁵, and Susan McCormick ¹
1. USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit., Peoria, IL. 61604, USA
2. Oak Ridge Institute for Science and Education, USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, Peoria, IL 61604, USA
3. Department of Agronomy, Kansas State University, Manhattan, KS 66506, USA
4. USDA-ARS, Hard Winter Wheat Genetics Research Unit, Manhattan, KS 66506, USA
5. Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
Corresponding Author: Guixia Hao, guixia.hao@usda.gov

Guixia Hao

Fusarium graminearum, the causal agent of Fusarium head blight (FHB), produces various mycotoxins that contaminate grains and cause profound health problems in humans and animals. Deoxynivalenol (DON) is the most common trichothecene mycotoxin occurring in contaminated grains. Our previous study showed that Arabidopsis expressing F. graminearum trichothecene 3-O-acetyltransferase (FgTRI101) can convert DON to 3-acetyldeoxynivalenol (3-ADON) and excrete it outside of Arabidopsis cells. To investigate whether wheat could similarly convert and excrete 3-ADON, potentially reducing the incidence of FHB and mycotoxin contamination, FgTRI101 was cloned and introduced into wheat cv Bobwhite, driven by the maize ubiquitin promoter (Ubi-1). Four independent transgenic lines containing FgTRI101 were identified. Gene expression studies revealed high expression levels of FgTRI101 in both wheat leaf and spike tissues in one of the transgenic lines (Tri101-1606). We compared the phytotoxic effects of purified DON on the root growth of transgenic wheat expressing FgTRI101. The seedlings from two FgTri101 transgenic wheat lines displayed significantly longer root lengths on media containing DON than the controls. However, the conversion of DON to 3-ADON in the FgTri101 transgenic wheat seedlings was only detected in the Tri101-1606 line inconsistently. FHB evaluation assays showed that transgenic wheat plants expressing FgTri101 enhanced FHB resistance. Significantly less DON accumulation was observed in FgTri101 expressing lines, but no 3-ADON was detected in infected wheat spikes, suggesting that 3-ADON is unstable in wheat. Our study suggests that utilizing the fungal self-protection mechanism is a promising method to control FHB and mycotoxin contamination.

 

This material is based upon work supported by the U.S. Department of Agriculture. This is a cooperative project with the U.S. Wheat & Barley Scab Initiative. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.