Dynamic of free and hidden fumonisins accumulation in maize during the growing season in relation with the cross-talk plant-pathogen - Preliminary results

It is well known that mycotoxins are stable metabolites able to increase during time, both in planta and in the exposed organisms. In studies regarding the dynamic of fumonisins accumulation in maize, a significant role of hybrids, years and growing location was detected. . Therefore, a hybrid-dependent implication of fatty acids in the plant-pathogen cross-talk inducing a modulation of fumonisin-related mechanisms in maize was hypothesised. In order to confirm these results and to study the role of oxilipinic profile in maize hybrids a field trial was organized. Ten maize hybrids grown in 5 different geographic areas (4 in Emilia Romagna and 1 in Lombardy) were considered in this study. In these maize fields, ears were sampled along the entire growing season, starting from early dough, that is considered the stage in which fumonisins start to be detected in kernels, till to harvest. Ears were shelled and the obtained kernels were used to quantify fungal presence (with particular attention to Fusarium spp), to detect free and hidden fumonisins content and for lipidomic analysis. Results obtained showed that an higher presence of fungi belonging to Genera Fusarium corrisponded to an higher presence of both free and hidden fumonisins but differences were found regarding both fungal incidence (both as infection and as CFU) and for fumonisins content detected along the growing season, with an important role played by maize hybrids and geographic area. The lipidomic approach was able to underline different lipidic species forming during the maize growing stages in all the hybrids considered and suggests the presence of a correlation between the oxilipinic profile (oxidized unsatured fatty acids) expressed by the hybrid, the fungal contamination level and the fumonisins content.