Penicillium roqueforti PR toxin gene cluster characterization

Area of Science:

• Mycology
• Molecular Biology
• Biochemistry

Background:

• PR toxin is a highly toxic isoprenoid mycotoxin produced by Penicillium roqueforti.
• This mycotoxin poses risks when found in food and animal feed.
• Understanding its biosynthesis is crucial for managing its presence.

Purpose of the Study:

• To identify and characterize the biosynthetic gene cluster for PR toxin in Penicillium roqueforti.
• To elucidate the enzymatic steps involved in PR toxin production.
• To propose a PR toxin biosynthesis pathway.

Main Methods:

• In silico analysis to identify the gene cluster.
• Gene silencing of specific genes (ORF5, ORF6, ORF8).
• Quantification of PR toxin, eremofortin A, and B production in transformants.

Main Results:

• A 22.4-kb gene cluster with 11 open reading frames involved in PR toxin biosynthesis was identified.
• Silencing of three genes (encoding acetyltransferase and P450 monooxygenases) reduced PR toxin production by 20-40%.
• Eremofortin A and B production was affected by gene silencing, suggesting their role as intermediates.

Conclusions:

• The identified gene cluster and its encoded enzymes are essential for PR toxin biosynthesis.
• A novel PR toxin biosynthesis pathway is proposed.
• This research provides a foundation for controlling PR toxin contamination.