# The Cytochrome P450 Enzyme SsCyp64 Mediates γ-linolenyl Alcohol in Regulating Sexual Mating/Filamentation and Pathogenicity of Sporisorium scitamineum

## TL;DR

This study shows how a specific enzyme in a sugarcane fungus helps control mating and disease by regulating a fatty alcohol and a key gene.

## Contribution

The study identifies SsCyp64 as a novel regulator of sexual mating and pathogenicity in Sporisorium scitamineum via γ-linolenyl alcohol and SsPRF1.

## Key findings

- Deleting SsCYP64 reduces SsPRF1 transcription, impairing sexual mating and filamentation.
- γ-linolenyl alcohol levels drop in SsCYP64 mutants, and adding it restores mating and SsPRF1 expression.
- SsCyp64 regulates dikaryotic hyphae formation by modulating γ-linolenyl alcohol and SsPRF1.

## Abstract

Sugarcane smut, caused by Sporisorium scitamineum, is a devastating fungal disease of sugarcane. Sexual mating/filamentation of opposite mating types is a key step in the infection and pathogenicity of S. scitamineum, yet its regulation remains unclear. In this study, we identified a cytochrome P450 enzyme-encoding gene, SsCYP64, which plays an important role in oxidative stress and maintaining cell membrane stability in S. scitamineum. Further investigations revealed that deletion of SsCYP64 leads to a decrease in the transcriptional level of SsPRF1, a key transcription factor regulating the sexual mating of S. scitamineum. Subsequently, the constitutive expression of SsPRF1 restored the defect in sexual mating/filamentation of the SsCYP64 deletion mutant, indicating that SsCyp64 regulates the sexual reproduction of S. scitamineum by mediating the transcriptional level of SsPRF1. In addition, metabolomic analysis revealed that the fatty alcohol metabolite γ-linolenyl alcohol significantly decreased in the SsCYP64 deletion mutant, whereas exogenous supplementation with γ-linolenyl alcohol increased the transcriptional level of SsPRF1 and partially restored the sexual mating/filamentation of the SsCYP64 deletion mutant. In conclusion, our results indicated that SsCyp64 mediated the transcription of SsPRF1 by modulating γ-linolenyl alcohol levels, thereby regulating the formation of dikaryotic hyphae in S. scitamineum. These findings provide new insights into the role of cytochrome P450 enzymes in the pathogenic process of plant pathogenic fungi.