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Updated: Jan 3, 2026
Genome-wide Analysis of Histone Modifications Distribution using the Chromatin Immunoprecipitation Sequencing Method in Magnaporthe oryzae
Published on: June 2, 2021
A histone deacetylase, MoHOS2 regulates asexual development and virulence in the rice blast fungus
Jongjune Lee1, Jae-Joon Lee1, Junhyun Jeon2
1Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan, 38541, Republic of Korea.
Abstract:
Histone acetylation/deacetylation represent a general and efficient epigenetic mechanism through which fungal cells control gene expression. Here we report developmental requirement of MoHOS2-mediated histone deacetylation (HDAC) for the rice blast fungus, Magnaporthe oryzae. Structural similarity and nuclear localization indicated that MoHOS2 is an ortholog of Saccharomyces cerevisiae Hos2, which is a member of class I histone deacetylases and subunit of Set3 complex. Deletion of MoHOS2 led to 25% reduction in HDAC activity, compared to the wild-type, confirming that it is a bona-fide HDAC. Lack of MoHOS2 caused decrease in radial growth and impinged dramatically on asexual sporulation. Such reduction in HDAC activity and phenotypic defects of ΔMohos2 were recapitulated by a single amino acid change in conserved motif that is known to be important for HDAC activity. Expression analysis revealed up-regulation of MoHOS2 and concomitant down-regulation of some of the key genes involved in asexual reproduction under sporulation-promoting condition. In addition, the deletion mutant exhibited defect in appressorium formation from both germ tube tip and hyphae. As a result, ΔMohos2 was not able to cause disease symptoms. Wound-inoculation showed that the mutant is compromised in its ability to grow inside host plants as well. We found that some of ROS detoxifying genes and known effector genes are de-regulated in the mutant. Taken together, our data suggest that MoHOS2-dependent histone deacetylation is pivotal for proper timing and induction of transcription of the genes that coordinate developmental changes and host infection in M. oryzae.
Insights
MoHOS2-mediated histone deacetylation is essential for the rice blast fungus Magnaporthe oryzae. Its absence impairs growth, sporulation, and host infection, highlighting its role in fungal development and pathogenicity.
Area of Science:
- Epigenetics
- Fungal Biology
- Plant Pathology
Background:
- Histone acetylation/deacetylation is a key epigenetic mechanism controlling gene expression in fungi.
- MoHOS2 is identified as a potential histone deacetylase (HDAC) in Magnaporthe oryzae, an ortholog of Saccharomyces cerevisiae Hos2.
- Understanding MoHOS2's function is crucial for comprehending epigenetic regulation in fungal pathogens.
Purpose of the Study:
- To investigate the role of MoHOS2-mediated histone deacetylation in the development and pathogenicity of Magnaporthe oryzae.
- To determine the impact of MoHOS2 deletion on fungal growth, sporulation, and host interaction.
- To elucidate the molecular mechanisms underlying MoHOS2's function in gene regulation.
Main Methods:
- Gene deletion and characterization of the resulting mutant (ΔMohos2).
- Measurement of histone deacetylase (HDAC) activity.
- Analysis of gene expression patterns, including genes involved in asexual reproduction and host infection.
- Assessment of fungal growth, sporulation, appressorium formation, and pathogenicity assays.
Main Results:
- Deletion of MoHOS2 significantly reduced HDAC activity and impaired radial growth and asexual sporulation.
- The ΔMohos2 mutant exhibited defects in appressorium formation and was non-pathogenic on rice plants.
- Expression analysis revealed deregulation of key genes involved in asexual reproduction, ROS detoxification, and effector functions in the ΔMohos2 mutant.
- A single amino acid change in a conserved HDAC motif recapitulated the phenotypic defects.
Conclusions:
- MoHOS2-dependent histone deacetylation is critical for regulating gene expression during developmental transitions in Magnaporthe oryzae.
- MoHOS2 plays a pivotal role in coordinating fungal development, including sporulation and appressorium formation.
- MoHOS2 is essential for the pathogenicity of Magnaporthe oryzae, affecting host infection processes.
- These findings underscore the importance of epigenetic regulation by MoHOS2 in fungal pathogenesis and host-pathogen interactions.
