Abstract

To cause rice blast disease, the fungus Magnaporthe oryzae develops a pressurized dome-shaped cell called an appressorium, which physically ruptures the leaf cuticle to gain entry to plant tissue. Here, we report that a toroidal F-actin network assembles in the appressorium by means of four septin guanosine triphosphatases, which polymerize into a dynamic, hetero-oligomeric ring. Septins scaffold F-actin, via the ezrin-radixin-moesin protein Tea1, and phosphatidylinositide interactions at the appressorium plasma membrane. The septin ring assembles in a Cdc42- and Chm1-dependent manner and forms a diffusion barrier to localize the inverse-bin-amphiphysin-RVS-domain protein Rvs167 and the Wiskott-Aldrich syndrome protein Las17 at the point of penetration. Septins thereby provide the cortical rigidity and membrane curvature necessary for protrusion of a rigid penetration peg to breach the leaf surface.

Links

Publisher Full Text

Authors

Dagdas YF, Yoshino K, Dagdas G, Ryder LS, Bielska E, Steinberg G, Talbot NJ

Institution

School of Biosciences, University of Exeter, Exeter, UK.

Source

Science (New York, N.Y.) 336:6088 2012 Jun 22 pg 1590-5

MeSH

Actin Cytoskeleton
Actins
Cell Membrane
Diffusion
Fungal Proteins
Magnaporthe
Microfilament Proteins
Mutation
Oryza sativa
Phosphatidylinositols
Plant Diseases
Plant Leaves
Protein Interaction Domains and Motifs
Recombinant Fusion Proteins
Septins
cdc42 GTP-Binding Protein

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

22723425