Deoxynivalenol glucosylation in commercial durum wheat cultivars under field conditions

PALACIOS, S; ERAZO, J.; CIASCA, B; LATANZZIO, V; REYNOSO M.M.; FARNOCHI, M.C; TORRES A.M.

Berlin

Congreso; XVIII International Plant Protection Congress; 2015

German Society for Plant Protection and Plant Health

Fusarium head blight (FHB) is a major fungal disease affecting wheat worldwide and it is caused mainly by species within the Fusarium graminearum species complex. The disease can severely reduce grain yield and quality and the infected grains could be contaminated with mycotoxins such as deoxynivalenol (DON). DON is phytotoxic and it is considered a virulence factor of thefungus, affecting the protein synthesis in plant cells. As a consequence, the formation of the ?masked? mycotoxin deoxinyvalenol-3-glucoside (D3G) results from a defense mechanism the plant uses for detoxification. This ability has been associated to resistance to FHB. The objective of this study was to evaluate de capacity of commercial durum wheat varieties toglucosylate DON to DON-3G under natural conditions in order to select promising varieties for wheat breeding programs screening for FHB-resistant germplasm. Wheat grain samples were obtained from commercial cultivars from 2013 and 2014harvest seasons in different localities (Balcarce, La Dulce, and Miramar) from the main durum wheat-producing area in Argentina. DON, its acetylated forms (3/15 ADON) and DON-3G were analyzed by HPLC MS/MS. A three way ANOVA was used to compare total DON content and % glucosylation versus variety, year and location. There were statistically significant interactions between year x location, year x variety and location x variety (p≤ 0.001) in DON accumulation. There was a significant difference in the total DON concentration between years, with a media of 1554.8 and 1954.8 μg/kg in 2013 and 2014,respectively. Alsosignificant differences were found between locations with the highest levels in Miramar and Balcarce. There was a positive correlation (r=0.89) between the DON and DON-3G content in the grains, and a negative correlation between DON content and % glucosylation. The level of glucosylation was not significantly different, and was not affected by the factors year and location. Furthermore, Buck Granate showed a good glucosylation activity towards DON and it is a promising candidate for further studies in wheat breeding programs.