The objective of the present study was to monitor the occurrence and distribution of a spectrum of trichothecene toxins in different parts of maize plants. Therefore maize plants were sampled randomly from 13 fields in southwest Germany and the fractions kernels, cobs, husks, stalks, leaves and rudimentary ears were analyzed for eight A-type and five B-type trichothecenes. Each of the toxins was found in at least three of the total of 78 samples. The study revealed that both A-type and B-type trichothecenes may be present in all parts of the maize plant but may be unevenly distributed. For the contents of deoxynivalenol, 3- and 15-acetyldeoxynivalenol, nivalenol, scirpentriol, 15-monoacetoxyscirpenol, HT-2 and T-2 toxin significant differences (p < 0.05) were found between different parts of the maize plants whereas no significant differences were observed for fusarenon-X, 4,15-diacetoxyscirpenol, neosolaniol, T-2 triol and T-2 tetraol. Up to twelve toxins co-occurring in one sample were detected. As a group B-type trichothecenes dominated over A-type trichothecenes concerning incidences and levels. Contamination was strongest with rudimentary ears based on incidence and mean and maximum contents; mean contents with few exceptions tended towards a higher level than in other fractions with significant (p < 0.05) differences compared to leaves for seven toxins.

Autoclaved oats were inoculated with a strain of Fusarium sporotrichioides or Fusarium poae. Moisture content of oats after inoculation was at 38%, incubation took place in standing culture at 28 °C. The A-type trichothecenes, 4,15-diacetoxyscirpenol (4,15-DAS), 15-monoacetoxyscirpenol (15-MAS), and scirpentriol (SCIRP) were analyzed by GC/MS. For each strain, three culture flasks were harvested at 2–3 day intervals starting immediately after inoculation. Total incubation time was 42 days (F. poae) and 56 days (F. sporotrichioides). Following peak accumulation, 4,15-DAS decreased below the detection limit for both strains, 15-MAS decreased below this limit for the isolate of F. sporotrichioides, for the isolate of F. poae it decreased to a level markedly below the peak value. SCIRP, after having peaked, decreased to some extent for the strain F. sporotrichioides, with a significant (P = 0.0029) negative linear regression of toxin content against culture age during this period. The content of 15-MAS, and in part also of 4,15-DAS, decreased along with an increase of SCIRP. This sequential accumulation pattern suggests the successive induction of esterases deacetylating 4,15-DAS and 15-MAS, as well as of enzymes involved in the metabolization of the parent alcohol, SCIRP. The results may explain, at least in part, the somewhat higher incidence in naturally contaminated compounds reported in the literature for SCIRP compared to 4,15-DAS and 15-MAS.