The peroxisomal matrix shuttling receptor Pex5 plays a role in FB1 production and virulence in Fusarium verticillioides

The peroxisomal matrix oxidase,catalase and peroxidase are imported peroxisomes through the shuttling receptors,which regulates the cellular oxidative homeostasis and function.Here,we report that PTS1 shuttling receptor FvPex5 is involved in the localization of PTS1,utilization of carbon sources and lipids,elimination ROS,cell wall stress,conidiation,fumonisin B_(1)(FB_(1))production,and virulence in maize pathogen Fusarium verticillioides.Significantly,differential expression of PTS1-,PTS2-,PEX-and FB_(1)toxin-related genes in wild type andΔFvpex5 mutant were examined by RNA-Seq analyses and confirmed by RT-PCR assay.In addition,different expression of PTS1 and PTS2 genes of theΔFvpex5 mutant were enriched in diverse biochemical pathways,such as carbon metabolism,nitrogen metabolism,lipid metabolism and the oxidation balance by combining GO and KEGG annotations.Overall,we showed that FvPex5 is involved in the regulation of genes associated with PTS,thereby affecting the oxidation balance,FB_(1)and virulence in F.verticillioides.The results help to clarify the functional divergence of Pex5 orthologs,and may provide a possible target for controlling F.verticillioides infections and FB_(1)biosynthesis.

Comparative Analysis of Mycotoxigenic Fungi and Mycotoxins Contaminating Soya Bean Seeds and Processed Soya Bean from Nigerian Markets

Concern for food safety has continued to grow worldwide including the issue of mycotoxin contamination of food products from farm to fork. In this regard, soya bean seeds and processed soya bean powder bought from some Nigerian markets were screened for fungal and mycotoxin contamination. Fungal identification was done by both conventional and molecular methods after samples were cultured on potato dextrose agar (PDA), ohio agricultural experimental station agar (OAESA), malt extract agar (MEA) and czapek yeast agar (CYA). Mycotoxin analysis by thin layer chromatography and high performance liquid chromatography was done after extraction and clean-up by multi-mycotoxin extraction procedure and solid phase extraction (SPE) isolute strong ion exchange (SAX) columns. Results from the analysis showed that soya bean seeds had higher incidences of fungal species such as Alternaria (52.4%) and Aspergillus flavus (42.9%). Mycotoxins detected include aflatoxins, ochratoxin A and fumonisin B with highest concentration of 3.430 μg/g, 0.125 μg/g and 4.286 μg/g respectively, which were below regulatory limits. The study showed that there was co-occurrence of aflatoxins and fumonisin B1 in both sample types and though these values are low, should not be ignored as a result of health risks associated with exposure to these compounds.

Protective effects of Amaranthus hybridus against aflatoxin B1 and fumonisin B1-induced genotoxicity in H4IIE-luc cells

Aim:Protective effects of aqueous extract of Amaranthus hybridus against afl atoxin B1(AFB_(1))and/or fumonisin B1(FB_(1))on the H4IIE-luc cell line were determined by use of the methyl thiazol tetrazolium viability assay and disruption of DNA integrity.Methods:H4IIE-luc cells were incubated with different concentrations of AFB_(1) and/or FB_(1) for 24 and 48 h with or without aqueous extract of A.hybridus.Results:AFB_(1) decreased the viability of cells after 24 and 48 h of exposure.EC_(50)values for AFB_(1) were 10.5 and 1.8μmol/L for the two periods,respectively.When the 48 h exposure to mycotoxin repeated with a pre-treatment of 20 and 40μg/mL extract of A.hybridus,the EC_(50)changed to 3.88 and 7.67μmol/L,respectively.H4IIE-luc cells exposed to FB_(1) for 24 h responded more than those incubated for 48 h.Cells treated with a combination of AFB_(1) and FB_(1) were less viable with a signifi cant decrease in the greater concentration.The mixture of AFB_(1) and FB_(1) resulted in a signifi cant threat to H4IIE-luc as indicated by the absence or appearance of new bands in random amplifi ed polymorphic DNA analysis,which demonstrated damage to DNA.The protective effects were probably due to greater content of total phenolics,carotenoids,β-carotene,folic-,linolenic-,linoleic and palmitic acids,as well as calcium,magnesium,iron,zinc,and selenium observed in the extract.Conclusion:Exposure to 40μg/mL of extract of A.hybridus protected cells from damage to DNA by stabilizing DNA.

Dietary incorporation of jojoba extract eliminates oxidative damage in livers of rats fed fumonisin-contaminated diet

Aim:This study aimed to determine the composition of ethanol extract of jojoba seeds,and to evaluate its hepatoprotective effects in rats fed fumonisin B1(FB1)-contaminated diet.Methods:Jojoba seeds were extracted in 95%ethanol,and the chemical composition was determined.Male rats were divided into six groups and treated for 8 weeks as follows:(1)Untreated control;(2)FB1-contaminated diet(80 mg/kg diet);(3)low dose(0.5 mg/kg b.w.)jojoba extract;(4)high dose(1.0 mg/kg b.w.)jojoba extract;(5)low dose jojoba extract plus FB1;and(6)high dose jojoba extract plus FB1.Blood and liver samples were collected for different biochemical analyses and histological examinations.Results:The results indicated that the ethanolic extract of jojoba is rich in protein,phenolic compounds,phytic acid,and considerable amounts of simmondsin.Animals fed FB1-contaminated diet showed severe biochemical and histological changes typical to those reported in literature.Treatment with jojoba seed extract alone at the two tested doses did not induce significant alterations in all parameters tested.Combined treatment of jojoba seed extract with FB1 eliminated hepatotoxicity induced by FB1,especially at low dose of jojoba seed extract.Conclusion:The authors concluded that jojoba seed extract can be incorporated in FB1-contaminated feed to eliminate FB1-induced hepatotoxicity.