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Updated: Jun 8, 2026
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Viability Assay of Trichoderma stromaticum Conidia Inside Human Peripheral Blood Mononuclear-Derived Macrophages
Published on: October 20, 2023
Ambient pH intrinsically influences Trichoderma conidiation and colony morphology
Johanna M Steyaert1, Richard J Weld, Alison Stewart
1Bio-Protection Research Centre, PO Box 84, Lincoln University, Lincoln 7647, New Zealand. johanna.steyaert@lincoln.ac.nz
Fungal Biology
|October 15, 2010
Summary
Low ambient pH influences conidiation in Trichoderma species. This study reveals complex pH effects on conidiation and anthraquinone excretion, highlighting species-specific responses and the role of media buffering.
Area of Science:
- Mycology
- Environmental Microbiology
- Fungal Physiology
Background:
- Conidiation in Trichoderma is influenced by ambient pH, with PacC-mediated pH regulation implicated.
- Previous research suggested Trichoderma hamatum does not conidiate upon mycelial injury.
Purpose of the Study:
- Investigate ambient pH effects on conidiation in three Trichoderma species (T. hamatum, T. atroviride, T. pleuroticola).
- Examine responses to a single blue-light burst and mycelial injury under varying pH conditions.
- Clarify the role of pH and media buffering in conidiation and anthraquinone excretion.
Main Methods:
- Exposing Trichoderma isolates to controlled pH conditions (buffered and unbuffered media).
- Inducing conidiation via a single blue-light burst or mycelial injury.
- Observing and quantifying conidiation and anthraquinone excretion.
Main Results:
- Trichoderma atroviride showed photoconidiation, indicating all cells are potentially competent.
- Trichoderma hamatum exhibited a clear injury response to conidiation at low pH (2.8-3.2).
- Trichoderma pleuroticola displayed pH-dependent colony morphologies and conidiation, influenced by media buffering.
- Anthraquinone excretion was strictly pH-dependent, irrespective of buffering.
Conclusions:
- Conidiation in Trichoderma is complex and depends on species, environmental triggers (light, injury), and media buffering.
- The buffering state of the medium, not just pH, significantly impacts the conidial phenotype, challenging the direct PacC regulation model for conidiation.
- Further research across multiple Trichoderma species is needed to fully understand ambient pH effects.
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