A putative MAP kinase kinase kinase, MCK1, is required for cell wall integrity and pathogenicity of the rice blast fungus, Magnaporthe oryzae

Junhyun Jeon, Jaeduk Goh, Sungyong Yoo, Myoung Hwan Chi, Jaehyuk Choi, Hee Sool Rho, Jongsun Park, Seong Sook Han, Ryun Kim Byeong, Sook Young Park, Soonok Kim, Yong Hwan Lee

Research output: Contribution to journalArticlepeer-review

95 Scopus citations

Abstract

Insertional mutagenesis of Magnaporthe oryzae led to the identification of MCK1, a pathogenicity gene predicted to encode mitogen-activated protein kinase kinase kinase (MAPKKK) homologous to BCK1 in Saccharomyces cerevisiae. Targeted disruption of MCK1 resulted in the fungus undergoing autolysis and showing hypersensitivity to cell-wall-degrading enzyme. The mck1 produced significantly reduced numbers of conidia and developed appressoria in a slightly retarded manner compared with the wild type. Appressorium of the mck1 mutant was unable to penetrate into plant tissues, thereby rendering the mutant nonpathogenic. Cytorrhysis assay and monitoring of lipid mobilization suggested that the appressorial wall was altered, presumably affecting the level of turgor pressure within appressorium. Furthermore, the mck1 mutant failed to grow inside plant tissue. Complementation of the mutated gene restored its ability to cause disease symptoms, demonstrating that MCK1 is required for fungal pathogenicity. Taken together, our results suggest that MCK1 is an MAPKKK involved in maintaining cell wall integrity of M. oryzae, and that remodeling of the cell wall in response to host environments is essential for fungal pathogenesis.

Original languageEnglish (US)
Pages (from-to)525-534
Number of pages10
JournalMolecular Plant-Microbe Interactions
Volume21
Issue number5
DOIs
StatePublished - May 2008
Externally publishedYes

Keywords

  • Agrobacterium tumefaciens-mediated transformation (ATMT)

ASJC Scopus subject areas

  • Physiology
  • Agronomy and Crop Science

Fingerprint

Dive into the research topics of 'A putative MAP kinase kinase kinase, MCK1, is required for cell wall integrity and pathogenicity of the rice blast fungus, Magnaporthe oryzae'. Together they form a unique fingerprint.

Cite this