title: Transcriptomic responses of the basidiomycete yeast Sporobolomyces sp. to the mycotoxin patulin.
abstract: BACKGROUND
  Patulin is a mycotoxin produced by Penicillium expansum, the causal agent of blue mold of stored pome fruits, and several other species of filamentous fungi. This mycotoxin has genotoxic, teratogenic and immunotoxic effects in mammals, and its presence in pome fruits and derived products represents a serious health hazard. Biocontrol agents in the Pucciniomycotina, such as the yeasts Sporobolomyces sp. strain IAM 13481 and Rhodosporidium kratochvilovae strain LS11, are able to resist patulin and degrade it into the less toxic compounds desoxypatulinic acid and ascladiol.
  
  
  RESULTS
  In this investigation we applied a transcriptomic approach based on RNAseq to annotate the genome of Sporobolomyces sp. IAM 13481 and then study the changes of gene expression in Sporobolomyces sp. exposed to patulin. Patulin treatment leads to ROS production and oxidative stress that result in the activation of stress response mechanisms controlled by transcription factors. Upregulated Sporobolomyces genes were those involved in oxidation-reduction and transport processes, suggesting the activation of defense mechanisms to resist patulin toxicity and expel the mycotoxin out of the cells. Other upregulated genes encoded proteins involved in metabolic processes such as those of the glutathione and thioredoxin systems, which are essential to restore the cellular redox homeostasis. Conversely, patulin treatment decreased the expression of genes involved in the processes of protein synthesis and modification, such as transcription, RNA processing, translation, protein phosphorylation and biosynthesis of amino acids. Also, genes encoding proteins involved in transport of ions, cell division and cell cycle were downregulated. This indicates a reduction of metabolic activity, probably due to the high energy requirement by the cells or metabolic arrest while recovering from the insult caused by patulin toxicity.
  
  
  CONCLUSIONS
  Complex mechanisms are activated in a biocontrol yeast in response to patulin. The genes identified in this study can pave the way to develop i) a biodetoxification process of patulin in juices and ii) a biosensor for the rapid and cost-effective detection of this mycotoxin.
authors.affiliation: Dipartimento di Agricoltura, Ambiente e Alimenti, Università degli Studi del Molise, Via F. De Sanctis snc, 86100, Campobasso, Italy. ianirig@umkc.edu.|Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO, 64110, USA. ianirig@umkc.edu.|Present address: Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA. ianirig@umkc.edu.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Ianiri
authors.affiliation: Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO, 64110, USA. alexander.idnurm@unimelb.edu.au.|School of BioSciences, University of Melbourne, Melbourne, VIC, 3010, Australia. alexander.idnurm@unimelb.edu.au.
authors.forename: Alexander
authors.initials: A
authors.lastname: Idnurm
authors.affiliation: Dipartimento di Agricoltura, Ambiente e Alimenti, Università degli Studi del Molise, Via F. De Sanctis snc, 86100, Campobasso, Italy. castoria@unimol.it.
authors.forename: Raffaello
authors.initials: R
authors.lastname: Castoria
mesh_terms: D000363:Agaricales / Q000187:drug effects / Q000235:genetics*; D061046:Biological Control Agents; D005516:Food Microbiology; D015966:Gene Expression Regulation, Fungal; D059014:High-Throughput Nucleotide Sequencing; D018384:Oxidative Stress; D010365:Patulin / Q000737:chemistry*; D010935:Plant Diseases / Q000382:microbiology; D012331:RNA, Fungal / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D017423:Sequence Analysis, RNA; D059467:Transcriptome
chemical_list: D061046:Biological Control Agents; D012331:RNA, Fungal; D017382:Reactive Oxygen Species; D010365:Patulin