Abstract
Deoxynivalenol (DON) is a toxicologically relevant trichothecene mycotoxin frequently found in cereal products. It is a virulence factor produced by the plant pathogen Fusarium graminearum during cereal crop infections. Investigating plant defense mechanisms is crucial for understanding plant resistance to F. graminearum and identifying new biocatalysts for DON detoxification. Previous studies identified DON-thiol adducts in cereal samples, indicating partial DON detoxification by glutathione transferases (GSTs). DON possesses two electrophilic centers for thiol conjugation, resulting in either epoxide opening at C13 or Michael addition at C10. At present, information on plant GSTs that catalyze these reactions is limited. In this study, Fusarium-inducible wheat GSTs were identified by analyzing the transcriptome of Fusarium-infected wheat heads. Twelve highly induced genes of the tau and phi GST classes were heterologously expressed and purified, biochemically characterized with model substrates, and assayed for activity with DON. Use of LC-MS showed that four of the selected tau class GSTs conjugated DON to GSH by epoxide opening (DON-13-GSH) and/or the reversible Michael addition reaction (DON-10-GSH). The crystal structure of a wheat GST (herein designated “TaGST-10”) in complex with DON-13-GSH was solved at a resolution of 2.3 Å and provided insights into the binding of DON at the active site of tau class GSTs. Our results corroborate the hypothesis that enzyme-catalyzed, GSH-mediated DON detoxification may be involved in plant response to Fusarium infection.
| Original language | English |
|---|---|
| Article number | 110600 |
| Journal | Journal of Biological Chemistry |
| Volume | 301 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - Oct 2025 |
| MoE publication type | A1 Journal article-refereed |
Funding
H. M. was funded by the Erwin-Schroedinger-Fellowship of the Austrian Science Fund (FWF; https://www.doi.org/10.55776/J4598). This research was funded in part also by the FWF Special Research Program SFB Fusarium [F3702, F3708, F3711, F3715; https://www.doi.org/10.55776/F37 ]. Further funding within the COMET project “Accelerated analysis” of the Austrian Competence Centre for Feed and Food Quality, Safety and Innovation (FFoQSI) is acknowledged. The COMET-K1 Competence Centre FFoQSI is funded by the Austrian federal ministries BMK, BMDW, and the Austrian provinces Lower Austria, Upper Austria and Vienna within the scope of COMET Competence Centers for Excellent Technologies. The program COMET is handled by the Austrian Research Promotion Agency FFG. We thank Gleb Bourenkov for assistance during data collection on the EMBL P13 beamline at PETRA III storage ring (DESY, Hamburg, Germany). Access to synchrotron beamtime was provided by European Union's Horizon 2020 project iNEXT-Discovery (grant agreement no. 871037). Biocenter Finland and Academy of Finland are thanked for infrastructure support. We further thank Franz Berthiller for providing his expertise and Krisztian Twaruschek for critically reading the manuscript. The Orbitrap IQ-X instrument was kindly provided by the BOKU Core Facility Bioactive Molecules: Screening and Analysis. H. M. M. S. N. E. L. A. C. P. and G. A. conceptualization; H. M. H. B. R. S. R. K. and G. A. funding acquisition; H. M. and G. A. project administration; H. M. M. H. W. S. K. G. K. K. F. X. M. and A. C. P. formal analysis; H. M. visualization; H. M. writing–original draft; H. M. M. S. L. K. M. D. A. M. C. H. W. S. and B. S. investigation; M. S. L. K. M. D. A. M. M. H. C. H. W. S. B. S. K. G. K. K. F. X. M. H. B. R. S. R. K. N. E. L. A. C. P. and G. A. writing–review and editing; L. K. M. D. A. M. and C. H. methodology; A. M. H. B. R. S. R. K. N. E. L. A. C. P. and G. A. supervision; K. G. K. and K. F. X. M. data curation; A. C. P. resources. H. M. was funded by the Erwin-Schroedinger-Fellowship of the Austrian Science Fund (FWF; https://www.doi.org/10.55776/J4598). This research was funded in part also by the FWF Special Research Program SFB Fusarium [F3702, F3708, F3711, F3715;https://www.doi.org/10.55776/F37]. Further funding within the COMET project “Accelerated analysis” of the Austrian Competence Centre for Feed and Food Quality, Safety and Innovation (FFoQSI) is acknowledged. The COMET-K1 Competence Centre FFoQSI is funded by the Austrian federal ministries BMK, BMDW, and the Austrian provinces Lower Austria, Upper Austria and Vienna within the scope of COMET Competence Centers for Excellent Technologies. The program COMET is handled by the Austrian Research Promotion Agency FFG. We thank Gleb Bourenkov for assistance during data collection on the EMBL P13 beamline at PETRA III storage ring (DESY, Hamburg, Germany). Access to synchrotron beamtime was provided by European Union’s Horizon 2020 project iNEXT-Discovery (grant agreement no. 871037). Biocenter Finland and Academy of Finland are thanked for infrastructure support. We further thank Franz Berthiller for providing his expertise and Krisztian Twaruschek for critically reading the manuscript. The Orbitrap IQ-X instrument was kindly provided by the BOKU Core Facility Bioactive Molecules: Screening and Analysis.
Keywords
- deoxynivalenol
- epoxide
- Fusarium
- glutathione transferase
- wheat