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Updated: Jul 19, 2026
Development of Metarhizium anisopliae as a Mycoinsecticide: From Isolation to Field Performance
Published on: July 30, 2017
Expression of genes involved in germination, conidiogenesis and pathogenesis in Metarhizium anisopliae using
Weiguo Fang1, Michael J Bidochka
1Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada.
Abstract:
Characterization of genes involved in germination, conidiogenesis and insect pathogenesis is an important step in identifying methods to increase the efficacy of Metarhizium anisopliae, a commercially important entomopathogenic fungus. Real-time RT-PCR is a sensitive, reproducible and quantitative method to study gene expression. However, it requires reliable reference gene transcripts for normalization. In this study, six putative housekeeping genes (act, gpd, 18sRNA, tef, try and ubi) were investigated as reliable reference genes. Transcripts from tef, gpd and try were found to be the most suitable reference genes for real-time RT-PCR analysis of genes expressed during germination, conidiogenesis and pathogenesis. Using these as reference genes, the relative expression levels of a virulence gene, a subtilisin-like protease (pr1), a regulator of G protein signaling gene involved in conidiogenesis (cag8), the nitrogen response regulator gene (nrr1), and a hydrophobin gene (ssga) were studied. None of these transcripts could be detected in the early stages of insect pathogenesis. The nitrogen response regulator, nrr1, was consistently expressed during all developmental stages. Expression levels of cag8 increased significantly in the later stages of conidiogenesis on insect cadavers. The expression level of ssga during conidiogenesis was significantly higher than that in mycelia during vegetative growth in nutrient rich media. The pr1 gene was expressed during fungal conidiation on the insect cadaver. This study acts as a foundation for investigating the transcriptional levels of genes expressed during germination, conidiogenesis and pathogenesis of M. anisopliae using real-time RT-PCR.
Insights
This study identifies reliable reference genes (TEF, GPD, TRY) for quantitative gene expression analysis in Metarhizium anisopliae. It provides a foundation for understanding fungal development and insect pathogenesis gene regulation.
Area of Science:
- Mycology
- Molecular Biology
- Biotechnology
Background:
- Metarhizium anisopliae is a key entomopathogenic fungus with commercial applications.
- Understanding gene expression during its life cycle is crucial for enhancing fungal efficacy.
- Quantitative gene expression analysis requires stable reference genes for accurate normalization.
Purpose of the Study:
- To identify suitable reference genes for real-time RT-PCR in Metarhizium anisopliae.
- To investigate the expression patterns of key genes involved in germination, conidiogenesis, and insect pathogenesis.
- To establish a foundation for future transcriptomic studies in M. anisopliae.
Main Methods:
- Evaluation of six candidate housekeeping genes (act, gpd, 18sRNA, tef, try, ubi) for stability.
- Selection of the most reliable reference genes (tef, gpd, try) using real-time RT-PCR.
- Quantification of virulence (pr1), conidiogenesis (cag8, ssga), and regulatory (nrr1) genes during different developmental stages.
Main Results:
- TEF, GPD, and TRY were validated as stable reference genes for M. anisopliae.
- Virulence and pathogenesis-related genes showed stage-specific expression patterns.
- NRR1 exhibited consistent expression across all developmental stages, while SSGA and CAG8 were upregulated during conidiogenesis.
Conclusions:
- TEF, GPD, and TRY are recommended for normalizing gene expression in M. anisopliae studies.
- Gene expression profiling provides insights into the regulation of fungal development and virulence.
- This research facilitates further investigation into the molecular mechanisms of M. anisopliae pathogenesis.
