MYCOLab Ai Logo - gold and army green

The palmitoyl-CoA ligase Fum16 is part of a Fusarium verticillioides fumonisin subcluster involved in self-protection

Summary

This research reveals how corn fungi protect themselves from their own toxic products by employing specialized defense enzymes. Scientists discovered that five genes work together in a protective cluster, with some enzymes strengthening the fungal cell’s natural defenses while others actively break down the toxin. This discovery helps explain how dangerous fungi survive and could lead to better strategies for preventing mycotoxin contamination in crops and developing disease-resistant plants.

Background

Fusarium verticillioides produces the mycotoxin fumonisin B1 (FB1), which disrupts sphingolipid biosynthesis by inhibiting ceramide synthase. The mechanisms by which F. verticillioides protects itself from its own mycotoxin are not completely understood, though some fumonisin cluster genes contribute to self-protection rather than biosynthesis.

Objective

This study aimed to uncover the functions of FUM15 and FUM16, two adjacent genes in the fumonisin biosynthetic cluster, and determine their role in protecting F. verticillioides from FB1 toxicity. The researchers hypothesized that both genes contribute to self-protection mechanisms against the mycotoxin.

Results

Fum16 was demonstrated to be a functional palmitoyl-CoA ligase that co-localizes with ceramide synthase Fum18 to the endoplasmic reticulum and contributes to sphingolipid biosynthesis. FUM15 encodes a P450 monooxygenase involved in FB1 modification and detoxification. FUM15-19 constitute a five-gene subcluster dedicated to fungal self-protection against FB1.

Conclusion

The study identifies a comprehensive self-protection mechanism in F. verticillioides involving a five-gene FUM subcluster. FUM16, FUM17, and FUM18 supplement ceramide biosynthesis, while FUM19 represses the FUM cluster and FUM15 detoxifies FB1, providing insights into mycotoxin self-protection mechanisms applicable to crop resistance and mycotoxin management strategies.
  • Published in:mBio,
  • Study Type:Experimental Study,
  • Source: PMID: 39704544
Scroll to Top