Ste2 receptor-mediated chemotropism of Fusarium graminearum contributes to its pathogenicity against wheat

Sci Rep. 2020 Jul 1;10(1):10770. doi: 10.1038/s41598-020-67597-z.

Abstract

Fusarium Head Blight of wheat, caused by the filamentous fungus Fusarium graminearum, leads to devastating global food shortages and economic losses. While many studies have addressed the responses of both wheat and F. graminearum during their interaction, the possibility of fungal chemotropic sensing enabling pathogenicity remains unexplored. Based on recent findings linking the pheromone-sensing G-protein-coupled receptor Ste2 to host-directed chemotropism in Fusarium oxysporum, we investigated the role of the Ste2 receptor and its downstream signaling pathways in mediating chemotropism of F. graminearum. Interestingly, a chemotropic response of growing hyphae towards catalytically active Triticum aestivum 'Roblin' cultivar secreted peroxidases was detected, with deletion of STE2 in F. graminearum leading to loss of the observed response. At the same time, deletion of STE2 significantly decreased infection on germinating wheat coleoptiles, highlighting an association between Ste2, chemotropism and infection by F. graminearum. Further characterization revealed that the peroxidase-directed chemotropism is associated with stimulation of the fungal cell wall integrity mitogen-activated protein kinase signaling cascade. Altogether, this study demonstrates conservation of Ste2-mediated chemotropism by Fusarium species, and its important role in mediating pathogenicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agrobacterium tumefaciens
  • Catalysis
  • Cell Wall / metabolism
  • Chemotaxis
  • Fungal Proteins / metabolism*
  • Fusarium / metabolism*
  • Gene Deletion
  • Hyphae / metabolism
  • Ligands
  • MAP Kinase Signaling System
  • Peroxidases / metabolism
  • Pheromones / metabolism
  • Plant Diseases / microbiology
  • Receptors, Mating Factor / metabolism*
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Signal Transduction
  • Spores, Fungal / metabolism
  • Triticum / microbiology*
  • Virulence

Substances

  • Fungal Proteins
  • Ligands
  • Pheromones
  • Receptors, Mating Factor
  • STE2 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Peroxidases

Supplementary concepts

  • Fusarium graminearum