A barley UDP-glucosyltransferase inactivates nivalenol and provides Fusarium head blight resistance in transgenic wheat

Authors: LI, XIN - University Of Minnesota; SCHWEIGER, WOLFGANG - University Of Natural Resources & Applied Life Sciences - Austria; MALACHOVA, ALEXANDRA - University Of Natural Resources & Applied Life Sciences - Austria; SHIN, SANGHYUN - University Of Minnesota; HUANG, YADONG - University Of Minnesota; DONG, YANHONG - University Of Minnesota; WIESENBERGER, GERLINDE - University Of Natural Resources & Applied Life Sciences - Austria; McCormick, Susan; LEMMENS, MARC - University Of Natural Resources & Applied Life Sciences - Austria; FRUHMANN, PHILIPP - Vienna University Of Technology

Submitted to: Journal of Experimental Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/21/2017
Publication Date: 4/12/2017
Citation: Li, X., Michlmayr, H., Schweiger, W., Malachova, A., Shin, S., Huang, Y., Dong, Y., Wiesenberger, G., McCormick, S., Lemmens, M., Fruhmann, P., et al. 2017. A barley UDP-glucosyltransferase inactivates nivalenol and provides Fusarium Head Blight resistance in transgenic wheat. Journal of Experimental Botany. 68(9):2187-2197.

Interpretive Summary: In this research we found that a barley gene may help to control Fusarium head blight (FHB). FHB, caused by the fungus Fusarium graminearum, is a devastating disease of small grain cereal crops that causes yield reductions and contamination of grain with the trichothecene mycotoxins nivalenol (NIV) and deoxynivalenol (DON). Nivalenol-producing isolates are most prevalent in Asia but co-exist with DON-producers in lower frequency in North America and Europe. These toxins are harmful to the health of humans and livestock because of its ability to block protein synthesis. They are also important virulence factor for FHB, therefore making plants that have greater resistance to these toxins is a way of improving resistance to the disease. In the study, a gene from barley for an enzyme that detoxifies DON and NIV was introduced into yeast, Arabidopsis and wheat. Wheat that expressed this barley gene was significantly more resistant to both the toxins and to FHB. This barley gene is a promising candidate for novel approaches to improve food safety and crop production by enhancing the Fusarium resistance of crop plants.

Technical Abstract: Fusarium Head Blight is a disease of cereal crops that causes severe yield losses and mycotoxin contamination of grain. The main causal pathogen, Fusarium graminearum, produces the trichothecene toxins deoxynivalenol or nivalenol as virulence factors. Nivalenol-producing isolates are most prevalent in Asia but co-exist with deoxynivalenol producers in lower frequency in North America and Europe. Previous studies identified a barley UDP-glucosyltransferase, HvUGT13248, that efficiently detoxifies deoxynivalenol, and when expressed in transgenic wheat results in high levels of type II resistance against deoxynivalenol-producing F. graminearum. Here we show that HvUGT13248 is also capable of converting nivalenol into the non-toxic nivalenol-3-O-ß-d-glucoside. We describe the enzymatic preparation of a nivalenol-glucoside standard and its use in development of an analytical method to detect the nivalenol-glucoside conjugate. Recombinant Escherichia coli expressing HvUGT13248 glycosylates nivalenol more efficiently than deoxynivalenol. Overexpression in yeast, Arabidopsis thaliana, and wheat leads to increased nivalenol resistance. Increased ability to convert nivalenol to nivalenol-glucoside was observed in transgenic wheat, which also exhibits type II resistance to a nivalenol-producing F. graminearum strain. Our results demonstrate the HvUGT13248 can act to detoxify deoxynivalenol and nivalenol and provide resistance to deoxynivalenol- and nivalenol-producing Fusarium.