How Peroxisomes Affect Aflatoxin Biosynthesis in Aspergillus Flavus
| Autor: | Flavia Pinzari, Nicaela Aspite, Gary A. Payne, Marzia Scarpari, Giorgia Cardinali, Anna Adele Fabbri, Valeria Scala, Corrado Fanelli, Carrie A. Smith, Massimo Reverberi, Marta Punelli, Slaven Zjalic |
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| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Aflatoxin
Applied Microbiology Fungal Physiology secondary metabolites peroxisomes Aspergillus flavus Oxidative stress lcsh:Medicine Aspergillus flavus Biochemistry Antioxidants Tombusvirus peroxisomes oxidative stress mycotoxins Aflatoxins Gene Expression Regulation Fungal heterocyclic compounds Fungal Biochemistry Promoter Regions Genetic lcsh:Science Hypolipidemic Agents chemistry.chemical_classification Multidisciplinary secondary metabolites Fatty Acids food and beverages Peroxisome Lipids Oxygen Metabolism Oxidation-Reduction Research Article Biotechnology Genetic Vectors Peroxisome Proliferation Mycology Biology Microbiology Fungal Proteins Superoxide dismutase Lipid Mediators Genetics Reactive oxygen species Superoxide Dismutase lcsh:R Fungi Lipid metabolism Metabolism Lipid Metabolism biology.organism_classification chemistry Small Molecules Oxidative stress biology.protein lcsh:Q Gene Function Bezafibrate Reactive Oxygen Species |
| Zdroj: | PLoS ONE, Vol 7, Iss 10, p e48097 (2012) PLoS ONE |
| Popis: | In filamentous fungi, peroxisomes are crucial for the primary metabolism and play a pivotal role in the formation of some secondary metabolites. Further, peroxisomes are important site for fatty acids β-oxidation, the formation of reactive oxygen species and for their scavenging through a complex of antioxidant activities. Oxidative stress is involved in different metabolic events in all organisms and it occurs during oxidative processes within the cell, including peroxisomal β-oxidation of fatty acids. In Aspergillus flavus, an unbalance towards an hyper-oxidant status into the cell is a prerequisite for the onset of aflatoxin biosynthesis. In our preliminary results, the use of bezafibrate, inducer of both peroxisomal β-oxidation and peroxisome proliferation in mammals, significantly enhanced the expression of pex11 and foxA and stimulated aflatoxin synthesis in A. flavus. This suggests the existence of a correlation among peroxisome proliferation, fatty acids β- oxidation and aflatoxin biosynthesis. To investigate this correlation, A. flavus was transformed with a vector containing P33, a gene from Cymbidium ringspot virus able to induce peroxisome proliferation, under the control of the promoter of the Cu, Zn-sod gene of A. flavus. This transcriptional control closely relates the onset of the antioxidant response to ROS increase, with the proliferation of peroxisomes in A. flavus. The AfP33 transformant strain show an up-regulation of lipid metabolism and an higher content of both intracellular ROS and some oxylipins. The combined presence of a higher amount of substrates (fatty acids-derived), an hyper- oxidant cell environment and of hormone-like signals (oxylipins) enhances the synthesis of aflatoxins in the AfP33 strain. The results obtained demonstrated a close link between peroxisome metabolism and aflatoxin synthesis. |
| Databáze: | OpenAIRE |
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