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 beta-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 beta-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 beta-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 beta-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.

How Peroxisomes Affect Aflatoxin Biosynthesis in Aspergillus Flavus / Reverberi, Massimo; Marta, Punelli; Slaven, Zjalic; Scarpari, Marzia; Scala, Valeria; Flavia, Pinzari; Fabbri, Anna Adele; Fanelli, Corrado; Sung Hwan, Yun. - In: PLOS ONE. - ISSN 1932-6203. - ELETTRONICO. - 7:10(2012), pp. 1 (e48097)-15. [10.1371/journal.pone.0048097]

How Peroxisomes Affect Aflatoxin Biosynthesis in Aspergillus Flavus

REVERBERI, Massimo;SCARPARI, MARZIA;SCALA, VALERIA;FABBRI, Anna Adele;FANELLI, Corrado;
2012

Abstract

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 beta-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 beta-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 beta-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 beta-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.
2012
secondary metabolites, peroxisomes, Aspergillus flavus, Oxidative stress
01 Pubblicazione su rivista::01a Articolo in rivista
How Peroxisomes Affect Aflatoxin Biosynthesis in Aspergillus Flavus / Reverberi, Massimo; Marta, Punelli; Slaven, Zjalic; Scarpari, Marzia; Scala, Valeria; Flavia, Pinzari; Fabbri, Anna Adele; Fanelli, Corrado; Sung Hwan, Yun. - In: PLOS ONE. - ISSN 1932-6203. - ELETTRONICO. - 7:10(2012), pp. 1 (e48097)-15. [10.1371/journal.pone.0048097]
File allegati a questo prodotto
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/485380
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? 27
  • Scopus 64
  • ???jsp.display-item.citation.isi??? 65
social impact