FgPal1 regulates morphogenesis and pathogenesis in Fusarium graminearum

Abstract

Ascospores are the primary inoculum in Fusarium graminearum, a causal agent of wheat head blight. In a previous study, FgPAL1 was found to be upregulated in the Fgama1 mutant and important for ascosporogenesis. However, the biological function of this well-conserved gene in filamentous ascomycetes is not clear. In this study, we characterized its functions in growth, differentiation and pathogenesis. The Fgpal1 mutant had severe growth defects and often displayed abnormal hyphal tips. It was defective in infectious growth in rachis tissues and spreading in wheat heads. The Fgpal1 mutant produced conidia with fewer septa and more nuclei per compartment than the wild type. In actively growing hyphal tips, FgPal1-GFP mainly localized to the subapical collar and septa. The FgPal1 and LifeAct partially co-localized at the subapical region in an interdependent manner. The Fgpal1 mutant was normal in meiosis with eight nuclei in developing asci but most asci were aborted. Taken together, our results showed that FgPal1 plays a role in maintaining polarized tip growth and coordination between nuclear division and cytokinesis, and it is also important for infectious growth and developments of ascospores by the free cell formation process.

Identification of the Causal Agent of Brown Leaf Spot on Kiwifruit and Its Sensitivity to Different Active Ingredients of Biological Fungicides

“…In general, F. graminearum is a causal pathogen of head blight or scab on barley (Hordeum), rice (Oryza), wheat (Triticum), and maize (Zea) stalk rot, as well as of spoilage on water bamboo shoots [9,10]. Its spores spread by wind or rain in the spring season and infect plants at optimal temperatures [11,12]. In addition to limiting healthy crop development, F. graminearum produces a variety of mycotoxins that pose safety risks to human and animal health [13].…”

FgCsn12 Is Involved in the Regulation of Ascosporogenesis in the Wheat Scab Fungus Fusarium graminearum

“…In previous studies, many genes, including FNG1 , AMD1 , and PAL1 , could fully complement their corresponding deletion mutants with GFP fusion constructs in F. graminearum [ 14 , 43 , 44 ]. In this study, FgCSN12 -GFP complemented the defects of the Fgcsn12 mutant in vegetative growth and asexual reproduction but not during the sexual development process.…”

Endocytic protein Pal1 regulates appressorium formation and is required for full virulence of Magnaporthe oryzae

“…Deletion of S. cerevisiae Pal1p results in spherical or pear‐shaped cell morphology (Carroll et al, 2012 ). Recently, two studies in the plant‐pathogenic fungi F. graminearum and U. virens have demonstrated roles for Pal1 in vegetative growth, conidial morphology, pathogenicity, polarized tip growth, and developments of ascospores (Chen et al, 2020 ; Yin et al, 2020 ). However, the Pal1 regulatory mechanisms in plant‐pathogenic fungi are still not well understood.…”

“…Recently, there have been two reports on the endocytosis‐related protein Pal1 in Fusarium graminearum and Ustilaginoidea virens (Chen et al, 2020 ; Yin et al, 2020 ). In F. graminearum , disruption of FgPAL1 leads to defects in vegetative growth, conidial morphology, and pathogenicity (Yin et al, 2020 ).…”

“…Recently, there have been two reports on the endocytosis‐related protein Pal1 in Fusarium graminearum and Ustilaginoidea virens (Chen et al, 2020 ; Yin et al, 2020 ). In F. graminearum , disruption of FgPAL1 leads to defects in vegetative growth, conidial morphology, and pathogenicity (Yin et al, 2020 ). In U. virens , in addition to participating in asexual development and full virulence, UvPal1 also interacts with other endocytic proteins as well as the septin protein Cdc11 (Chen et al, 2020 ).…”