Septin-mediated plant cell invasion by the rice blast fungus, Magnaporthe oryzae.
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.
School of Biosciences, University of Exeter, Exeter, UK.
Yasin F
YF
Dagdas
Kae
K
Yoshino
Gulay
G
Dagdas
Lauren S
LS
Ryder
Ewa
E
Bielska
Gero
G
Steinberg
Nicholas J
NJ
Talbot
D008841:Actin Cytoskeleton / Q000502:physiology* / Q000648:ultrastructure; D000199:Actins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D004058:Diffusion; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020082:Magnaporthe / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology / Q000648:ultrastructure; D008840:Microfilament Proteins / Q000378:metabolism; D009154:Mutation; D012275:Oryza / Q000382:microbiology*; D010716:Phosphatidylinositols / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D054730:Protein Interaction Domains and Motifs; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D058112:Septins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism
D000199:Actins; D005656:Fungal Proteins; D008840:Microfilament Proteins; D010716:Phosphatidylinositols; D011993:Recombinant Fusion Proteins; D058112:Septins; D020764:cdc42 GTP-Binding Protein