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Mycotoxin Production (mycotoxin + production)
Selected AbstractsCONTAMINATION OF GRAINS BY MYCOTOXIN-PRODUCING MOLDS AND MYCOTOXINS AND CONTROL BY GAMMA IRRADIATIONJOURNAL OF FOOD SAFETY, Issue 3 2006NAGY H. AZIZ ABSTRACT Ninety random grain samples were collected and analyzed for mycotoxins, and the effect of gamma irradiation on the production of mycotoxins in grains was studied. Aspergillus, Penicillium, Mucor, Rhizopus, Fusarium, Alternaria, Scopulariopsis and Cladosporium were the most common fungal genera isolated from grains. Aspergillus flavus, Aspergillus niger, Aspergillus candidus, Aspergillus ochraceus, Penicillium citrinum, Penicillium expansum, Penicillium citreonigrum, Penicillium purpurogenum, Penicillium griseofulvum and Penicillium verrucosumwere the most common Aspergillus and Penicillium species in grains. Out of 120 Aspergillus and Penicillium isolates, 80 were mycotoxin producers. Analysis of grains revealed the occurrence of aflatoxin B1 ochratoxin A, cycolopiazonic acid and citrinin. Of the 90 samples, 67 were positive for one or more mycotoxin. Irradiation of grains at dose of 2.0 and 4.0 kGy decreased significantly the total fungal counts compared with unirradiated controls. After 100 days of storage at room temperature, the unirradiated grains were contaminated with high concentrations of mycotoxins as compared with irradiated 4.0-kGy samples. Mycotoxin production in grains decreased with increasing irradiation doses and was not detected at 6.0 kGy over 100 days of storage. [source] Solid substrate bioassay to evaluate impact of Trichoderma on trichothecene mycotoxin production by Fusarium speciesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2008Maciej Busko Abstract BACKGROUND:Fusarium head blight of wheat is a destructive disease in various wheat-growing regions and leads to significant yield losses for farmers and to contamination of cereal grains with mycotoxins, mainly deoxynivalenol and its derivatives. Toxigenic Fusarium species sporulate on cereal crop residues and produce significant inoculum for epidemics. Reduction of mycotoxin production and pathogen sporulation may be influenced by saprophytic fungal antagonists. RESULTS:Trichoderma isolates were examined in dual culture bioassays on rice with two isolates of Fusarium graminearum Schwabe and two isolates of Fusarium culmorum (W.G. Smith) Saccardo, belonging to three different chemotypes. Production of five trichothecene mycotoxins, deoxynivalenol (DON), 3-acetyl-deoxynivalenol (3AcDON), 15-acetyl-deoxynivalenol (15AcDON), nivalenol (NIV) and fusarenone X (FUS), was reduced by over 95%. Two Trichoderma isolates partially reduced the amounts of four metabolites when inoculated on autoclaved cultures of the same four Fusarium isolates. However, in the case of the 15AcDON chemotype of F. culmorum culture the content of DON increased and that of 15AcDON decreased. Isolates of Trichoderma varied in their ability to inhibit production of the five trichothecene mycotoxins by Fusarium. Susceptibility of the four Fusarium isolates to antagonistic activity of the same Trichoderma isolate differed significantly. CONCLUSION: Selected non-toxigenic Trichoderma isolates proved to be useful biocontrol agents against toxigenic Fusarium pathogens of wheat, significantly reducing production of the trichothecene mycotoxins DON, NIV and their acetylated derivatives. Copyright © 2007 Society of Chemical Industry [source] NPR1 and EDS11 contribute to host resistance against Fusarium culmorum in Arabidopsis buds and flowersMOLECULAR PLANT PATHOLOGY, Issue 5 2008ALAYNE CUZICK SUMMARY The cereal ear blight fungal pathogen Fusarium culmorum can infect Arabidopsis floral tissue, causing disease symptoms and mycotoxin production. Here we assessed the effect of seven mutants and one transgenic overexpression line, residing in either the salicylic acid (SA), jasmonic acid (JA) or ethylene (ET) defence signalling pathways, on the outcome of the Fusarium,Arabidopsis floral interaction. The bacterial susceptiblity mutant eds11 was also assessed. Flowering plants were spray inoculated with F. culmorum conidia to determine the host responses to initial infection and subsequent colonization. Enhanced susceptibility and higher concentrations of deoxynivalenol mycotoxin were observed in buds and flowers of the npr1 and eds11 mutants than in the wild-type Col-0 plants. An effect of the other two defence signalling pathways on disease was either absent (ET/JA combined), absent/minimal (ET) or inconclusive (JA). Overall, this study highlights a role for NPR1 and EDS11 in basal defence against F. culmorum in some floral organs. This is the first time that any of these well-characterized defence signalling mutations have been evaluated for a role in floral defence in any plant species. [source] | ||||||||||