Effetto di differenti condizioni ambientali sull'accumulo di fumonisine libere e mascherate e sul profilo ossilipinico in mais inoculato artificialmente con Fusarium verticillioides

[Autom. eng. transl.] Fumonisins are a structurally related group of mycotoxins produced by Fusarium verticillioides, one of the most important pathogens of maize. Recently, new forms have been identified, defined as masked, which are not detectable using standard methods of analysis, but only after an alkaline hydrolysis of the matrix. It has been hypothesized that these derive from the complexation of toxins with proteins or starch. In our study, samples of maize kernels belonging to 3 different hybrids, taken at harvest maturation, were taken to 2 different levels of aw (0.90 and 0.99), and inoculated with a toxigenic strain of F. verticillioides (106 spores / mL). The samples were then incubated at different temperatures (T: 20, 25 and 30 ° C) for different incubation times (0, 14 and 28 days). On the so obtained samples the analyzes were carried out relative to the fumonisins content in free and masked form and to the profile of some genes related to the production of oxylipins (in particular of 3 isoforms of linoleate diol synthase (lds1-2-3) and of a lipoxygenase (lox1)). The preliminary results show that the synthesis of fumonisins, both in the free form and in the masked one, can be detected already from 14 days of incubation with concentrations greater than both at 28 days; however, the statistical analysis shows a significant increase only in the masked part. The influence of the hybrid was significant, as well as that of T and aw, with greater production at 20 ° C and 0.90 aw. Concerning the expression of genes related to the production of oxylipins, the results seem to suggest a correlation with the inverse production of FB between the trend of the 3 genes lds and of the direct type for that of the lox1 gene.