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Genome-wide Analysis of Histone Modifications Distribution using the Chromatin Immunoprecipitation Sequencing Method in Magnaporthe oryzae
Published on: June 2, 2021
Telomere hypervariability in Magnaporthe oryzae.
1Department of Plant Pathology, Plant Science Building, 1405 Veteran's Drive, University of Kentucky, Lexington, KY 40546, USA.
Molecular Plant Pathology
|June 23, 2010
Summary
Gray leaf spot pathogens (Magnaporthe oryzae) show high genetic similarity internally, suggesting a recent origin. However, their telomeres are highly diverse, indicating rapid evolution at chromosome ends.
Area of Science:
- Plant pathology
- Mycology
- Genetics
Background:
- Gray leaf spot disease affects perennial ryegrass and tall fescue.
- The causal agent is the fungus Magnaporthe oryzae (anamorph = Pyricularia oryzae).
- Understanding the genetic diversity of this pathogen is crucial for disease management.
Purpose of the Study:
- To investigate the genetic diversity among 22 isolates of the gray leaf spot pathogen.
- To explore the evolutionary origin of Magnaporthe oryzae affecting turfgrasses.
- To compare genetic diversity at internal chromosomal loci versus telomeric regions.
Main Methods:
- Utilized single-copy and repetitive DNA markers for genetic analysis.
- Employed Southern hybridization and mating tests.
- Used Pot2 and MGR583 probes for repetitive DNA fingerprinting.
- Analyzed telomere diversity using a telomere probe.
Main Results:
- Single-copy DNA markers revealed minimal polymorphism (3/95 fragments), indicating low diversity in the genome.
- All isolates possessed the MAT1-2 mating-type allele.
- Repetitive DNA fingerprinting showed high similarity (>85%) among isolates.
- Telomere fingerprinting revealed extreme divergence (<20% similarity) among isolates.
- Telomere mutations were frequent, observed during vegetative growth and across different isolation methods.
Conclusions:
- The internal genome of gray leaf spot pathogens exhibits low diversity, suggesting a recent evolutionary origin.
- Telomeric regions are highly dynamic and rapidly evolving in Magnaporthe oryzae.
- Telomere instability may play a significant role in the adaptation and evolution of this turfgrass pathogen.
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