Sporobolomyces sp. IAM13481 Raw sequence reads

Patulin (PAT) is produced by Penicillium expansum, the causal agent of blue mold of stored pome fruits. This mycotoxin has genotoxic, teratogenic and immunotoxic effects, and its presence in pome fruits and derived products represents a serious health hazard. Biocontrol agents (BCAs) such as Rhodosporidium kratochvilovae and Sporobolomyces sp., are able to degrade PAT into the less toxic compounds desoxypatulinic acid and ascladiols. In this work, we investigated the changes of gene expression in Sporobolomyces sp. exposed to PAT through RNAseq. PAT treatment causes cellular redox homeostasis alteration that results in oxidative stress, which leads to the activation of stress response mechanisms controlled by transcription factors. Upregulated Sporobolomyces genes were those involved in oxidation-reduction process, transport, and glutathione and thioredoxin systems, indicating the activation of defense mechanisms to resist PAT toxicity, restore the cellular redox homeostasis and expel the mycotoxin out of the cells. Conversely, PAT treatment decreased the expression of genes involved in the processes of protein synthesis and modification, ions transport, cell division and cell cycle. This indicates a reduction of metabolic activity probably due to the high energy requirement of the yeast cells, which need to recover from insult caused by PAT toxicity. Although PAT degradation needs to be further investigated through gene/protein discovery, this study outlines the complex mechanisms activated by a BCA in response to the mycotoxin and set the basis for i) the biodetoxification of PAT in fruit juices, and ii) the development of a user-friendly biosensor for its rapid and cost-effective detection.