Equisetin

The responses to artificial spike inoculation with Fusarium culmorum were compared in 11 Tritordeum lines, two durum wheat cultivars and one naked barley cultivar. Inoculation of Tritordeum spikes led to a significant decrease in spike weight, kernel weight per spike, and kernel weight (by 18, 28, and 16 %, respectively). Durum wheat responded most strongly to inoculation, particularly with regard to spike weight and kernel weight per spike (decrease of 42 % and 53 %, respectively). Inoculation induced a significant increase in the total concentration of trichothecenes (9902 vs 558 μg/kg in non-inoculated control) and other Fusarium toxins (40,207 vs 3250 μg/kg in non-inoculated control) in Tritordeum grain. The content of three Alternaria toxins was not significantly modified by inoculation. The principal component analysis (PCA) of all fungal metabolites supported the discrimination of control and inoculated grain, and the results were used to divide the examined Tritordeum lines into two groups with different mycotoxin profiles. The first group (five lines) was more similar to naked barley, whereas the second group (six lines) showed greater similarity to durum wheat. The analyzed Tritordeum lines responded differently to inoculation, which suggests that lines with a low propensity to accumulate Fusarium toxins in grain can be selected from the existing gene pool. The study also demonstrated that Tritordeum grain accumulates significantly smaller amounts of mycotoxins than durum wheat grain.

Fungal-plant interactions have persisted for 460 million years, and almost all terrestrial plants on Earth have endophytic fungi. However, the mechanism of symbiosis between endophytic fungi and host plants has been inconclusive. In this dissertation, we used a strain of endophytic Fusarium lateritium (Fl617), which was found in the previous stage to promote disease resistance in tomato, and selected the pathogenic Fusarium oxysporum Fo4287 and endophytic Fusarium oxysporum Fo47, which are in the same host and the closest relatives of Fl617, to carry out a comparative genomics analysis of the three systems and to provide a new perspective for the elucidation of the special lifestyle of the fungal endophytes. We found that endophytic F. lateritium has a smaller genome, fewer clusters and genes associated with pathogenicity, and fewer plant cell wall degrading enzymes (PCWDEs). There were also relatively fewer secondary metabolisms and typical Fusarium spp. toxins, and a lack of the key Fusarium spp. pathogenicity factor, secreted in xylem (SIX), but the endophytic fungi may be more sophisticated in their regulation of the colonization process. It is hypothesized that the endophytic fungi may have maintained their symbiosis with plants due to the relatively homogeneous microenvironment in plants for a long period of time, considering only plant interactions and discarding the relevant pathogenicity factors, and that their endophytic evolutionary tendency may tend to be genome streamlining and to enhance the fineness of the regulation of plant interactions, thus maintaining their symbiotic status with plants.