Glycogen synthase AfGsy2 regulates mycelial growth, stress response, predatory activity, and chlamydospore development in the nematode-trapping fungus Arthrobotrys flagrans.
- 1State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan Key Laboratory of Basic Research and Innovative Application for Green Biological Production, Yunnan University, Kunming, China.
- 2School of Ecology and Environment, Yunnan University, Kunming, China.
Abstract
Introduction
Glycogen is a universal carbon and energy reserve that plays crucial roles in fungal stress adaptation, cellular homeostasis, and predatory activity. However, the role of glycogen metabolism in nematode-trapping fungi has largely remained unexplored. Here, we performed a systematic functional characterization of AfGsy2, the glycogen synthase-encoding gene in the biocontrol fungus Arthrobotrys flagrans.Methods
Using a CRISPR-Cas9-mediated deletion mutant, together with overexpression and complementation strains, we investigated the involvement of AfGsy2 in mycelial growth, stress tolerance, trap formation, nematicidal activity against Caenorhabditis elegans, chlamydospore production and germination, and glycogen accumulation. Subcellular localization was examined using an AfGsy2-GFP fusion protein.Results
Deletion of AfGsy2 reduced hyphal growth on both nutrient-rich and nutrient-poor media but enhanced tolerance to osmotic, salt, and oxidative stresses, suggesting that blocked glycogen synthesis may trigger metabolic rerouting toward alternative stress-protective compounds. Notably, the ΔAfGsy2 mutants exhibited reduced trap production and nematicidal activity against C. elegans, whereas overexpression of AfGsy2 accelerated these processes, suggesting a link between glycogen metabolism and predatory activity. Moreover, AfGsy2 positively regulated chlamydospore production, glycogen accumulation, and chlamydospore germination. AfGsy2-GFP predominantly localized to the vacuoles of chlamydospores, and complementation restored the mutant phenotypes to wild-type levels.Discussion
Collectively, these findings uncover a link between glycogen metabolism and growth, stress resilience, sporulation, and predatory activity in A. flagrans, and establish a molecular foundation for the rational improvement of nematode-trapping fungi. Together, these results identify AfGsy2 as a pleiotropic regulator linking glycogen metabolism to biocontrol-related traits.
Related
- A hierarchical regulatory cascade programs chlamydospore formation in the nematode-trapping fungus Arthrobotrys flagrans
- Nitrate regulates anchor root development
- Editorial Note: Early Growth Response Gene-2 (Egr-2) Regulates the Development of B and T Cells
- An ITK - SLP-76 Y173 Axis Regulates TCR Signal Persistence and Thymic Development
- A transcription factor regulates development of a bacteria-housing eukaryotic cell through DNA damage mitigation
BibTeX
@article{shi2026glycogen,
title = {{Glycogen synthase AfGsy2 regulates mycelial growth, stress response, predatory activity, and chlamydospore development in the nematode-trapping fungus Arthrobotrys flagrans.}},
author = {Qianfei Shi and Yu Zhang and Minghe Mo and Guohong Li},
journal = {Frontiers in cellular and infection microbiology},
year = {2026},
month = oct,
doi = {10.3389/fcimb.2026.1891167},
url = {https://europepmc.org/article/MED/42908527},
note = {CC BY},
}
RIS
TY - JOUR
TI - Glycogen synthase AfGsy2 regulates mycelial growth, stress response, predatory activity, and chlamydospore development in the nematode-trapping fungus Arthrobotrys flagrans.
AU - Qianfei Shi
AU - Yu Zhang
AU - Minghe Mo
AU - Guohong Li
PY - 2026
DA - 2026/10/07
JO - Frontiers in cellular and infection microbiology
DO - 10.3389/fcimb.2026.1891167
UR - https://europepmc.org/article/MED/42908527
AB - Introduction Glycogen is a universal carbon and energy reserve that plays crucial roles in fungal stress adaptation, cellular homeostasis, and predatory activity. However, the role of glycogen metabolism in nematode-trapping fungi has largely remained unexplored. Here, we performed a systematic functional characterization of AfGsy2, the glycogen synthase-encoding gene in the biocontrol fungus Arthrobotrys flagrans.Methods Using a CRISPR-Cas9-mediated deletion mutant, together with overexpression and complementation strains, we investigated the involvement of AfGsy2 in mycelial growth, stress tolerance, trap formation, nematicidal activity against Caenorhabditis elegans, chlamydospore production and germination, and glycogen accumulation. Subcellular localization was examined using an AfGsy2-GFP fusion protein.Results Deletion of AfGsy2 reduced hyphal growth on both nutrient-rich and nutrient-poor media but enhanced tolerance to osmotic, salt, and oxidative stresses, suggesting that blocked glycogen synthesis may trigger metabolic rerouting toward alternative stress-protective compounds. Notably, the ΔAfGsy2 mutants exhibited reduced trap production and nematicidal activity against C. elegans, whereas overexpression of AfGsy2 accelerated these processes, suggesting a link between glycogen metabolism and predatory activity. Moreover, AfGsy2 positively regulated chlamydospore production, glycogen accumulation, and chlamydospore germination. AfGsy2-GFP predominantly localized to the vacuoles of chlamydospores, and complementation restored the mutant phenotypes to wild-type levels.Discussion Collectively, these findings uncover a link between glycogen metabolism and growth, stress resilience, sporulation, and predatory activity in A. flagrans, and establish a molecular foundation for the rational improvement of nematode-trapping fungi. Together, these results identify AfGsy2 as a pleiotropic regulator linking glycogen metabolism to biocontrol-related traits.
SN - 2235-2988
ER -