UDP-Glucosyltransferases from Rice, Brachypodium, and Barley: Substrate Specificities and Synthesis of Type A and B Trichothecene-3-O-β-d-glucosides

Toxins

Marc Lemmens¹  Marta Piątkowska²  Alexandra Malachová²  Franz Berthiller²  Jana Šofrová²  Elisabeth Varga²  Gerhard Adam³  Herbert Michlmayr³  Christian Hametner⁴  Philipp Fruhmann⁴  Günther Jaunecker⁵  Georg Häubl⁵ 

[1] Biotechnology in Plant Production, IFA-Tulln, BOKU, Konrad Lorenz Str. 20, 3430 Tulln, Austria;Christian Doppler Laboratory for Mycotoxin Metabolism and Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), BOKU, Konrad Lorenz Str. 20, 3430 Tulln, Austria;Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, (BOKU), Konrad Lorenz Str. 24, 3430 Tulln, Austria;Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getreidemarkt 9/163, 1060 Vienna, Austria;Romerlabs Division Holding GmbH, Technopark 1, 3430 Tulln, Austria;

关键词: Fusarium head blight;    phase II detoxification;    masked mycotoxin;    NMR;    cereals;   

DOI  :  10.3390/toxins10030111

来源: DOAJ

【 摘 要 】

Trichothecene toxins are confirmed or suspected virulence factors of various plant-pathogenic Fusarium species. Plants can detoxify these to a variable extent by glucosylation, a reaction catalyzed by UDP-glucosyltransferases (UGTs). Due to the unavailability of analytical standards for many trichothecene-glucoconjugates, information on such compounds is limited. Here, the previously identified deoxynivalenol-conjugating UGTs HvUGT13248 (barley), OsUGT79 (rice) and Bradi5g03300 (Brachypodium), were expressed in E. coli, affinity purified, and characterized towards their abilities to glucosylate the most relevant type A and B trichothecenes. HvUGT13248, which prefers nivalenol over deoxynivalenol, is also able to conjugate C-4 acetylated trichothecenes (e.g., T-2 toxin) to some degree while OsUGT79 and Bradi5g03300 are completely inactive with C-4 acetylated derivatives. The type A trichothecenes HT-2 toxin and T-2 triol are the kinetically preferred substrates in the case of HvUGT13248 and Bradi5g03300. We glucosylated several trichothecenes with OsUGT79 (HT-2 toxin, T-2 triol) and HvUGT13248 (T-2 toxin, neosolaniol, 4,15-diacetoxyscirpenol, fusarenon X) in the preparative scale. NMR analysis of the purified glucosides showed that exclusively β-D-glucosides were formed regio-selectively at position C-3-OH of the trichothecenes. These synthesized standards can be used to investigate the occurrence and toxicological properties of these modified mycotoxins.

【 授权许可】

Unknown