RNA-Seq Reveals OTA-Related Gene Transcriptional Changes in Aspergillus carbonarius

PLoS One. 2016 Jan 14;11(1):e0147089. doi: 10.1371/journal.pone.0147089. eCollection 2016.

Abstract

Ochratoxin A (OTA) is a mycotoxin harmful for animals and humans. Aspergillus carbonarius is the main responsible for OTA contamination of grapes and derived products. Gene transcriptional profiling of 4 A. carbonarius strains was carried out by RNA-Seq analysis to study transcriptome changes associated with OTA production. By comparing OTA inducing (OTAI) vs. non-inducing (OTAN) cultural conditions, a total of 3,705 differentially expressed genes (DEGs) (fold change > |2| and FDR ≤ 0.05) were identified. Several genes involved in primary metabolic processes, with particular regard to carbohydrate and amino acid metabolisms, secondary metabolic processes, transport, response to stress and sporulation were up-regulated by OTAI conditions at all the analysed sampling times (4, 6 and 8 DAI) or starting from 6 DAI. Highly up-regulated DEGs encoding enzymes involved in biosynthesis of secondary metabolites, oxidoreductases, transporters and transcription factors were examined for their potential involvement in OTA biosynthesis and related metabolic pathways. Differential expression of genes encoding polyketide synthases (pks), non-ribosomal peptide synthetases (nrps) and chloroperoxidase (cpo) was validated by RT-qPCR. Among clusters of co-regulated genes involved in SM biosynthesis, one putative OTA-gene cluster, including both pks and nrps genes, was detected in the A. carbonarius genome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspergillus / genetics*
  • Aspergillus / metabolism*
  • Cluster Analysis
  • Gene Expression Profiling
  • Gene Expression Regulation, Fungal*
  • High-Throughput Nucleotide Sequencing
  • Multigene Family
  • Ochratoxins / biosynthesis*
  • Reproducibility of Results
  • Transcriptome*

Substances

  • Ochratoxins
  • ochratoxin A

Grants and funding

The work was partially carried out in the framework of the Projects: “Laboratory network for the selection, characterization and conservation of germplasm and for preventing the spread of economically-relevant and quarantine pests (SELGE) No. 14”, founded by the Apulia Region, PO FESR 2007–2013—Axis I, Line of intervention 1.2., Action 1.2.1; “Promotion of ECO-friendly processes for the enhancement of quality of apulian food productions” granted by the “Distretto Agroalimentare Regionale – D.A.Re. s.c.ar.l.. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.