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Updated: Jun 12, 2026
Gene Expression Profiling of Infecting Microbes Using a Digital Bar-coding Platform
Published on: January 13, 2016
Large scale parallel analysis of gene expression during infection-related morphogenesis of Magnaporthe grisea
Yoshitaka Takano1, Woobong Choi, Thomas K Mitchell
1Laboratory of Plant Pathology, Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan.
Abstract:
SUMMARY The rice blast fungus Magnaporthe grisea causes one of the most destructive diseases of rice. To initiate the infection of host tissues, conidia elaborate germ tubes that differentiate specialized infection structures called appressoria. Microarrays composed of 3500 cDNAs of M. grisea were prepared for the identification of genes that are specifically up- or down-regulated during appressorium formation. Gene expression in ungerminated conidia, during appressorium formation, and during mycelial growth was investigated with a novel highly sensitive dendrimer based detection system. Transcripts of 85 different genes were found to be more abundant in ungerminated conidia and/or in conidia with developing appressoria than in vegetative mycelia. Nineteen of these showed higher expression in both ungerminated conidia and developing appressoria than in mycelia, suggesting that their expression remains elevated during the early stage of fungal infection. The expression of 18 genes was higher in ungerminated conidia than in developing appressoria, indicating their possible role in the germination process or maintaining dormancy. Transcripts of 47 genes were found to be more abundant in developing appressoria than in ungerminated conidia, suggesting that their expression is induced during appressorium formation. Several of these genes, including a chitin binding protein and infection structure specific protein MIF23, were previously shown to be preferentially expressed during appressorium formation. However, the expression of many of these genes has not been reported prior to this analysis. In contrast, transcripts of 38 different genes were found to be more abundant in mycelia than in developing appressoria. A Northern blot analysis of selected genes was consistent with the microarray results. Results from this study provide a powerful resource for furthering our understanding of gene expression during infection-related morphogenesis and for the functional analysis of M. grisea genes involved in fungal infection.
Insights
Researchers identified genes crucial for rice blast fungus infection. They analyzed gene expression during appressorium formation, revealing key genes for fungal development and host invasion.
Area of Science:
- Plant Pathology
- Molecular Mycology
- Fungal Genetics
Background:
- Magnaporthe grisea causes rice blast, a devastating plant disease.
- Appressoria are specialized infection structures essential for fungal invasion.
Purpose of the Study:
- Identify genes differentially expressed during appressorium formation in M. grisea.
- Understand gene regulation underlying infection-related morphogenesis.
Main Methods:
- Utilized microarrays with 3500 M. grisea cDNAs.
- Analyzed gene expression in ungerminated conidia, developing appressoria, and mycelia.
- Employed a sensitive dendrimer-based detection system and Northern blot analysis.
Main Results:
- Identified 85 genes with altered expression during early infection stages.
- Found 47 genes specifically induced during appressorium formation.
- Discovered 18 genes potentially involved in conidial germination or dormancy.
Conclusions:
- This study provides a valuable gene expression dataset for M. grisea infection.
- Highlights genes critical for appressorium development and fungal pathogenesis.
- Facilitates functional analysis of M. grisea genes in rice blast disease.
