An increase in trichothecene accumulation was revealed in most of the tebuconazole-treated samples of all chemotypes. Notably, a huge increase in all

trichothecene compounds was revealed in samples of all chemotypes treated with 5 mg L−1 of tebuconazole. In an in planta experiment, fungal DNA and trichothecene accumulation were assessed in grain samples collected from Afatinib molecular weight wheat heads treated with different concentrations of azoles tested (Table 4). A higher amount of 3ADON DNA was quantitated with qPCR in the sample treated with 125 mg L−1 of propiconazole. Correspondingly, the highest levels of DON were detected in this sample. Two samples treated with 125 and 5 mg L−1 of propiconazole showed a higher amount of NIV DNA. Similarly, the highest level of NIV was detected in these samples. In samples treated with tebuconazole, an increase in 3ADON DNA as compared to the positive control was found in a sample treated with 3 mg L−1 of tebuconazole, although the increase was not significant. In this sample, the highest levels of DON/3ADON were detected. In this experiment, a high correlation was found between the amount of Alectinib fungal DNA and trichothecene compounds (Table 5). The lack of a strong relationship between 15ADON DNA and DON could result from the high production of this compound by the 3ADON chemotype. Azoles are widely used fungicides in agriculture (Paul et al., 2010; Mesterházy et al., 2011)

and to treat human mycosis (Giavini & Menegol, 2010). Their antifungal activity is based on their ability to inhibit CYP51, a key enzyme in ergosterol biosynthesis (Liu et al., 2010). Azoles have been shown to differ in the control of Fusarium spp., and their unsatisfactory effectiveness may be associated with an insufficient concentration of fungicides in plant tissues (Mesterházy et al., 2011). In the most recent study, Audenaert et al. (2010) showed that the treatment of F. graminearum with sublethal concentrations of prothioconazole resulted in increased

accumulation of DON. It has been further many demonstrated that the enhancement of DON production was indicated by the oxidative stress caused by fungicide treatment. Hydrogen peroxide (H2O2) triggers trichothecene biosynthesis in DON chemotypes of F. culmorum/F. graminearum, although NIV chemotypes seem to show higher adaptation to oxidative stress (Ponts et al., 2009). It has been demonstrated that treatment of NIV chemotypes with H2O2 results in decreased accumulation of this toxin (Ponts et al., 2009). In this study, we showed that treatment of either DON or NIV chemotypes of F. graminearum with sublethal concentrations of azoles results in increased tri transcript levels, which leads to increased accumulation of trichothecenes. This observation is supported by studies of Ochiai et al. (2007) showing that sublethal concentrations of tebuconazole increased tri5 transcript level in genetically engineered F. asiaticum and increased production of NIV-type trichothecenes.