FgPsd2, a phosphatidylserine decarboxylase of Fusarium graminearum, regulates development and virulence

Phosphatidylserine decarboxylases (Psds) are enzymes regulating phosphatidylethanolamine biosynthesis in prokaryotes and eukaryotes, and have the central role in lipid metabolism. To date, the functions of Psds in plant pathogenic fungi are not fully understood. In this study, we have characterized two yeast Psd orthologues: FgPsd1 and FgPsd2, in Fusarium graminearum. Our results indicate that FgPsd1 and FgPsd2 are localized in mitochondria and Golgi, respectively. In addition, we have determined that FgPsd1 is a lethal gene and deletion of FgPsd2 resulted in a significant reduction of mycelial growth and conidiation. Futhermore, the FgPsd2 deletion mutant (Delta FgPsd2) is defective in ascospore production and virulence in wheat. Our study has also found that the Delta FgPsd2 mutant is more sensitive to osmotic and oxygen stresses. Moreover, deletion of FgPsd2 reduced the formation of lipid droplets and aggravated autophagy in F. graminearum. In summary, our findings indicate that FgPsd2 is important for mycelial growth, sexual and asexual reproduction, virulence, lipid droplet formation and autophagy in F. graminearum.

Automated summary

Our study characterized two yeast Psd orthologues, FgPsd1 and FgPsd2, in Fusarium graminearum, with FgPsd1 localized in mitochondria and FgPsd2 in Golgi. Deletion of FgPsd2 resulted in impaired mycelial growth, reproduction, virulence, lipid droplet formation, and autophagy in F. graminearum. The findings suggest that FgPsd2 plays a crucial role in multiple cellular processes in this fungus.