The Fungicidal Activity of Tebuconazole Enantiomers against Fusarium graminearum and Its Selective Effect on DON Production under Different Conditions

Abstract

Tebuconazole, which consists of a pair of enantiomers with different fungicidal activities, is one of the most common fungicides used in the control of Fusarium graminearum. In this study, the fungicidal activity of rac-tebuconazole and its enantiomers against F. graminearum was determined at 0.997, 0.975, and 0.950 a and at 20, 25, and 30 °C on wheat-based media. Then, F. graminearum was treated with rac-tebuconazole and its enantiomers at the EC, EC, and EC levels under different culture conditions, and DON production was measured. Finally, expression of the DON biosynthetic genes ( TRI5 and TRI6) was quantified by real-time RT-PCR after incubation with EC doses of rac-tebuconazole and its enantiomers for 4, 8, and 14 days at 30 °C and a 0.997. The results showed that the fungicidal activity of tebuconazole was strongly influenced by temperature, a, and the combined factors. (-)-Tebuconazole is higher in fungicidal activity than (+)-tebuconazole and rac-tebuconazole with 24-99-fold and 1.8-6.7-fold, respectively. However, (-)-tebuconazole was generally more favorable for DON production than (+)-tebuconazole under the same conditions. Additionally, (-)-tebuconazole and rac-tebuconazole induced significantly increased expression of the DON biosynthetic genes ( TRI5 and TRI6) compared to the control by the 14th day of treatment. In this research, the combination condition of 30 °C and 0.997 a is the most suitable for DON production by F. graminearum. The test strains of F. graminearum treated with the EC dose of (-)-tebuconazole produced the greatest amounts of DON.

Application method affects pesticide efficiency and effectiveness in wheat fields

“…The occurrence of mycotoxins in wheat grains is of great concern for both human and animal health . Some fungicides, including tebuconazole and metconazole, significantly decrease mycotoxins levels, whereas others such as azoxystrobin have no effect and can even increase DON accumulation (e.g. the quinone outside inhibitor class of fungicides) .…”

Recent Advances in the Treatment of Scedosporiosis and Fusariosis

“…Multi-locus sequence typing (MLST) is currently viewed as the best option for the identification of Fusarium isolates on the species level, and enzyme-linked immunosorbent assay (ELISA) is the preferred method in Fusarium to identify specific mycotoxins [ 51 , 53 , 54 , 55 ]. As noted above, MALDI-TOF MS is a promising new tool for rapid identification and classification of cultured microorganisms based on their protein spectra [ 56 , 57 , 58 ].…”

“…often display high levels of resistance to existing antifungal agents and are some of the more difficult fungi to treat [ 62 , 64 , 65 ]. Data on their in-vitro susceptibility to various antifungal agents indicate variable susceptibility amphotericin B and extended-spectrum triazoles, such as itraconazole, voriconazole, isavuconazole and posaconazole [ 51 , 53 , 54 , 66 , 67 ]. For this reason, we typically initiate empirical therapy with an antifungal triazole and a poleyene, such as voriconazole and liposomal amphotericin B, while awaiting antifungal susceptibilities.…”

Evaluation of exploitive potential for higher bioactivity and lower residue risk enantiomer of chiral fungicide pydiflumetofen

“…1 Meanwhile, some of these pathogens can produce numerous mycotoxins, such as zearalenone and deoxynivalenol, that cause a serious health risks to animals and humans. 2,3 Fungicides play an extremely important role in agricultural production through the prevention, elimination, and control of phytopathogens. 4,5 succinate dehydrogenase inhibitor (SDHI) fungicides such as benzovindiflupyr, penflufen, penthiopyrad, and pydiflumetofen have been the most active fungicides developed in recent years.…”