Two independent S-phase checkpoints regulate appressorium-mediated plant infection by the rice blast fungus Magnaporthe oryzae

Mariam Oses-Ruiz, Wasin Sakulkoo, George R. Littlejohn, Magdalena Martin-Urdiroz, Nicholas J. Talbot

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)
11 Downloads (Pure)

Abstract

To cause rice blast disease, the fungal pathogen Magnaporthe oryzae develops a specialized infection structure called an appressorium. This dome-shaped, melanin-pigmented cell generates enormous turgor and applies physical force to rupture the rice leaf cuticle using a rigid penetration peg. Appressorium-mediated infection requires septin-dependent reorientation of the F-actin cytoskeleton at the base of the infection cell, which organizes polarity determinants necessary for plant cell invasion. Here, we show that plant infection by M. oryzae requires two independent S-phase cell-cycle checkpoints. Initial formation of appressoria on the rice leaf surface requires an S-phase checkpoint that acts through the DNA damage response (DDR) pathway, involving the Cds1 kinase. By contrast, appressorium repolarization involves a novel, DDR-independent S-phase checkpoint, triggered by appressorium turgor generation and melanization. This second checkpoint specifically regulates septin- dependent, NADPH oxidase-regulated F-actin dynamics to organize the appressorium pore and facilitate entry of the fungus into host tissue.

Original languageEnglish
Pages (from-to)E237-E244
Number of pages8
JournalProceedings of the National Academy of Sciences
Volume114
Issue number2
Early online date27 Dec 2016
DOIs
Publication statusPublished - 10 Jan 2017

Keywords

  • fungi
  • pathogen
  • Pyricularia
  • appressorium
  • cell cycle
  • ASPERGILLUS-NIDULANS
  • DNA-DAMAGE
  • CELL-CYCLE
  • GRISEA
  • PENETRATION
  • GROWTH
  • BIOLOGY
  • KINASE
  • YEAST
  • PATHOGENICITY

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