poae DNA at lower concentrations, although a more sensitive rDNA-based TaqMan assay was applied. The differences obtained can PCI-32765 molecular weight most probably be explained by the increased amplification efficiency (98.5–99.8%) of the esyn1-based
TaqMan assay used in this study, which resulted in higher amplicon levels quantified in comparison with previous studies, where the amplification efficiency of the assay used was 91%. Additional qualitative PCR analyses with species-specific primers for F. avenaceum (Turner et al., 1998) and F. tricinctum (Kulik, 2008) were performed in order to detect the presence of F. avenaceum and F. tricinctum in the samples analyzed. The results showed that F. avenaceum was only present in all samples harvested in 2007 where higher amounts of enniatins were detected, while the presence of F. tricinctum was revealed in all samples analyzed (data not shown). These results support the previous results of the studies of Logrieco et al. (2002) and Jestoi et al. (2004a, b) showing that F. avenaceum is responsible to a large extent for the increase in the enniatins content in grain samples. It seems that F. poae and F. tricinctum are the most frequent contaminants of wheat with low enniatins levels, Lumacaftor ic50 even if environmental conditions did not promote the development of FHB. Although several studies demonstrated
correlations between Fusarium DNA and the mycotoxin concentration in cereal samples, it should not be assumed that the amount of genes of interest would in each case relate to the level of corresponding mycotoxins. Recent studies by Jurado et al. (2008) and Marín et al. (2010) demonstrated that the expression of genes involved in mycotoxin synthesis depends on different environmental factors. Additionally, the fungal strains can synthesize mycotoxins at different concentrations (Bakan et al., 2002). On the other hand, discrepancies between chemical and DNA-based methods may
result from the ability of plants to hide fungal toxins such as glucosides (Berthiller et al., 2005), although, to date, no glucosylation Coproporphyrinogen III oxidase or other conjugation process is known for enniatins. Yli-Mattila et al. (2006, 2008) found a correlation between the levels of F. avenaceum and F. poae DNA analyzed using the TaqMan assay and enniatins in highly contaminated barley grain samples, although the correlation was not confirmed in samples with lower amount of mycotoxins. Similarly, in our previous studies, no correlation was revealed between F. poae DNA and the levels of enniatins in asymptomatic wheat samples with very low levels of enniatins (Kulik & Jestoi, 2009). In this study, Pearson’s correlation analyses were used to determine whether the amounts of esyn1 genotypes were related to the total amount of enniatins. A significant positive correlation was found between the amount of F. avenaceum/F. tricinctum esyn1 genotype (R=0.61, P=0.00001) and the total amount of enniatins (Fig. 1). In the case of F.