{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T04:52:03Z","timestamp":1791348723563,"version":"4.3.1"},"reference-count":34,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T00:00:00Z","timestamp":1791331200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2023YFD1400400"],"award-info":[{"award-number":["2023YFD1400400"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Infect. Microbiol."],"abstract":"\n Introduction<\/jats:title>\n \n 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\n AfGsy2<\/jats:italic>\n , the glycogen synthase-encoding gene in the biocontrol fungus\n Arthrobotrys flagrans<\/jats:italic>\n .\n <\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n 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\n Caenorhabditis elegans<\/jats:italic>\n , chlamydospore production and germination, and glycogen accumulation. Subcellular localization was examined using an AfGsy2-GFP fusion protein.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n Deletion of\n AfGsy2<\/jats:italic>\n 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\n \u0394AfGsy2<\/jats:italic>\n mutants exhibited reduced trap production and nematicidal activity against\n C. elegans<\/jats:italic>\n , whereas overexpression of\n AfGsy2<\/jats:italic>\n 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.\n <\/jats:p>\n <\/jats:sec>\n \n Discussion<\/jats:title>\n \n Collectively, these findings uncover a link between glycogen metabolism and growth, stress resilience, sporulation, and predatory activity in\n A. flagrans<\/jats:italic>\n , 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.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fcimb.2026.1891167","type":"journal-article","created":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T04:48:50Z","timestamp":1791348530000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Glycogen synthase AfGsy2 regulates mycelial growth, stress response, predatory activity, and chlamydospore development in the nematode-trapping fungus Arthrobotrys flagrans"],"prefix":"10.3389","volume":"16","author":[{"given":"Qianfei","family":"Shi","sequence":"first","affiliation":[{"name":"State 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","place":["Kunming, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu","family":"Zhang","sequence":"additional","affiliation":[{"name":"State 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","place":["Kunming, China"]},{"name":"School of Ecology and Environment, Yunnan University","place":["Kunming, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Minghe","family":"Mo","sequence":"additional","affiliation":[{"name":"State 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","place":["Kunming, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guohong","family":"Li","sequence":"additional","affiliation":[{"name":"State 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","place":["Kunming, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,10,7]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1003604","article-title":"Glycogen metabolic genes are involved in trehalose-6-phosphate synthase-mediated regulation of pathogenicity by the rice blast fungus Magnaporthe oryzae","volume":"9","author":"Badaruddin","year":"2013","journal-title":"PloS Pathog."},{"key":"B2","doi-asserted-by":"publisher","first-page":"911","DOI":"10.1080\/09583157.2022.2094891","article-title":"Overview of the nematophagous fungus Duddingtonia flagrans","volume":"32","author":"Balbino","year":"2022","journal-title":"Biocontrol Sci. Technol."},{"key":"B3","doi-asserted-by":"publisher","first-page":"547","DOI":"10.1002\/jobm.202100039","article-title":"In vitro evaluation of physicochemical variables on the nematophagous fungus Duddingtonia flagrans","volume":"61","author":"C\u00e9spedes-Guti\u00e9rrez","year":"2021","journal-title":"J. Basic Microbiol."},{"key":"B4","doi-asserted-by":"publisher","first-page":"W242","DOI":"10.1093\/nar\/gky354","article-title":"CRISPOR: intuitive guide selection for CRISPR\/Cas9 genome editing experiments and screens","volume":"46","author":"Concordet","year":"2018","journal-title":"Nucleic Acids Res."},{"key":"B5","doi-asserted-by":"publisher","first-page":"40","DOI":"10.1016\/j.fgb.2015.03.014","article-title":"Glycogen catabolism, but not its biosynthesis, affects virulence of Fusarium oxysporum on the plant host","volume":"77","author":"Corral-Ramos","year":"2015","journal-title":"Fungal Genet. Biol."},{"key":"B6","doi-asserted-by":"publisher","first-page":"17r","DOI":"10.1093\/glycob\/cwg047","article-title":"New insights on trehalose: a multifunctional molecule","volume":"13","author":"Elbein","year":"2003","journal-title":"Glycobiology"},{"key":"B7","doi-asserted-by":"publisher","first-page":"1851","DOI":"10.1099\/00221287-147-7-1851","article-title":"Trehalose is required for the acquisition of tolerance to a variety of stresses in the filamentous fungus Aspergillus nidulans","volume":"147","author":"Fillinger","year":"2001","journal-title":"Microbiology"},{"key":"B8","doi-asserted-by":"publisher","first-page":"S19","DOI":"10.1016\/j.fgb.2008.07.018","article-title":"Biodiversity and evolution of primary carbon metabolism in Aspergillus nidulans and other Aspergillus spp","volume":"46","author":"Flipphi","year":"2009","journal-title":"Fungal Genet. Biol."},{"key":"B9","doi-asserted-by":"publisher","first-page":"183","DOI":"10.1016\/0304-4165(78)90130-7","article-title":"Glycogen synthesis in the fungus Neurospora crassa","volume":"540","author":"Fontana","year":"1978","journal-title":"Biochim. Biophys. Acta"},{"key":"B10","doi-asserted-by":"publisher","first-page":"125","DOI":"10.1111\/j.1574-6976.2001.tb00574.x","article-title":"Reserve carbohydrates metabolism in the yeast Saccharomyces cerevisiae","volume":"25","author":"Fran\u00e7ois","year":"2001","journal-title":"FEMS Microbiol. Rev."},{"key":"B11","doi-asserted-by":"publisher","first-page":"517","DOI":"10.1111\/j.1365-2958.2010.07119.x","article-title":"KRE genes are required for beta-1,6-glucan synthesis, maintenance of capsule architecture and cell wall protein anchoring in Cryptococcus neoformans","volume":"76","author":"Gilbert","year":"2010","journal-title":"Mol. Microbiol."},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1128\/microbiolspec.FUNK-0022-2016","article-title":"Nematode-trapping fungi","volume":"5","author":"Jiang","year":"2017","journal-title":"Microbiol. Spectr."},{"key":"B13","doi-asserted-by":"publisher","first-page":"1145","DOI":"10.1534\/genetics.111.128264","article-title":"Regulation of cell wall biogenesis in Saccharomyces cerevisiae: the cell wall integrity signaling pathway","volume":"189","author":"Levin","year":"2011","journal-title":"Genetics"},{"key":"B14","doi-asserted-by":"publisher","first-page":"20180317","DOI":"10.1098\/rstb.2018.0317","article-title":"Signal pathways involved in microbe-nematode interactions provide new insights into the biocontrol of plant-parasitic nematodes","volume":"374","author":"Liang","year":"2019","journal-title":"Philos. Trans. R. Soc Lond. B. Biol. Sci."},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2319707121","article-title":"A fungal protein organizes both glycogen and cell wall glucans","volume":"121","author":"Loza","year":"2024","journal-title":"Proc. Natl. Acad. Sci. U.S.A."},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1016\/j.exppara.2023.108592","article-title":"Efficacy of Duddingtonia flagrans (Bioverm\u00ae) on the biological control of buffalo gastrointestinal nemaodes","volume":"253","author":"Mendes","year":"2023","journal-title":"Exp. Parasitol."},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1128\/msphere.00575-24","article-title":"Glycogen synthase activity in Candida albicans is partly controlled by the functional ortholog of Saccharomyces cerevisiae Gac1p","volume":"9","author":"Miao","year":"2024","journal-title":"mSphere"},{"key":"B18","doi-asserted-by":"publisher","first-page":"197","DOI":"10.1590\/1519-6984.209748","article-title":"Duddingtonia flagrans preying a plant parasitic nematode","volume":"80","author":"Monteiro","year":"2020","journal-title":"Braz. J. Biol."},{"key":"B19","doi-asserted-by":"publisher","first-page":"71","DOI":"10.1016\/j.biocontrol.2018.05.003","article-title":"Nematophagus fungi increasing phosphorus uptake and promoting plant growth","volume":"123","author":"Monteiro","year":"2018","journal-title":"Biol. Control"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2020.01358","article-title":"Characterization of novel broad-host-range bacteriophage DLP3 specific to Stenotrophomonas maltophilia as a potential therapeutic agent","volume":"24","author":"Peters","year":"2020","journal-title":"Front. Microbiol."},{"key":"B21","doi-asserted-by":"publisher","first-page":"1703","DOI":"10.1105\/tpc.12.9.1703","article-title":"MAP kinase and protein kinase A-dependent mobilization of triacylglycerol and glycogen during appressorium turgor generation by Magnaporthe grisea","volume":"12","author":"Thines","year":"2000","journal-title":"Plant Cell"},{"key":"B22","doi-asserted-by":"publisher","first-page":"499","DOI":"10.1111\/j.1567-1364.2011.00740.x","article-title":"The Saccharomyces cerevisiae fermentation stress response protein Igd1p\/Yfr017p regulates glycogen levels by inhibiting the glycogen debranching enzyme","volume":"11","author":"Walkey","year":"2011","journal-title":"FEMS Yeast Res."},{"key":"B23","doi-asserted-by":"publisher","first-page":"1762","DOI":"10.1038\/s42003-025-09144-y","article-title":"GSK3 phosphorylates and activates trehalose-6-phosphate synthase to improve trehalose production and thermotolerance in Ganoderma lucidum","volume":"8","author":"Wang","year":"2025","journal-title":"Commun. Biol."},{"key":"B24","doi-asserted-by":"publisher","first-page":"283","DOI":"10.1111\/1462-2920.16282","article-title":"Establishment of Arthrobotrys flagrans as biocontrol agent against the root pathogenic nematode Xiphinema index","volume":"25","author":"Wernet","year":"2023","journal-title":"Environ. Microbiol."},{"key":"B25","doi-asserted-by":"publisher","first-page":"952","DOI":"10.1111\/j.1574-6976.2010.00220.x","article-title":"Regulation of glycogen metabolism in yeast and bacteria","volume":"34","author":"Wilson","year":"2010","journal-title":"FEMS Microbiol. Rev."},{"key":"B26","doi-asserted-by":"publisher","first-page":"622","DOI":"10.1007\/s004380100455","article-title":"Characterization of Gac1p, a regulatory subunit of protein phosphatase type I involved in glycogen accumulation in Saccharomyces cerevisiae","volume":"265","author":"Wu","year":"2001","journal-title":"Mol. Genet. Genomics"},{"key":"B27","doi-asserted-by":"publisher","first-page":"8379","DOI":"10.1073\/pnas.0702770104","article-title":"Evolution of nematode-trapping cells of predatory fungi of the Orbiliaceae based on evidence from rRNA-encoding DNA and multiprotein sequences","volume":"104","author":"Yang","year":"2007","journal-title":"Proc. Natl. Acad. Sci. U.S.A."},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pgen.1008029","article-title":"Intercellular communication is required for trap formation in the nematode-trapping fungus Duddingtonia flagrans","volume":"15","author":"Youssar","year":"2019","journal-title":"PloS Genet."},{"key":"B29","doi-asserted-by":"publisher","first-page":"5462","DOI":"10.1038\/s41467-021-25535-1","article-title":"Fatal attraction of Caenorhabditis elegans to predatory fungi through 6-methyl-salicylic acid","volume":"12","author":"Yu","year":"2021","journal-title":"Nat. Commun."},{"key":"B30","doi-asserted-by":"publisher","DOI":"10.3390\/jof9040467","article-title":"RNAPII degradation factor Def1 is required for development, stress response, and full virulence of Magnaporthe oryzae","volume":"9","author":"Zhang","year":"2023","journal-title":"J. Fungi"},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.3390\/microorganisms13081847","article-title":"FlbD: a regulator of hyphal growth, stress resistance, pathogenicity, and chlamydospore production in the nematode-trapping fungus Arthrobotrys flagrans","volume":"13","author":"Zhang","year":"2025","journal-title":"Microorganisms"},{"key":"B32","doi-asserted-by":"publisher","DOI":"10.1128\/spectrum.00186-23","article-title":"AfLaeA, a global regulator of mycelial growth, chlamydospore production, pathogenicity, secondary metabolism, and energy metabolism in the nematode-trapping fungus Arthrobotrys flagrans","volume":"11","author":"Zhang","year":"2023","journal-title":"Microbiol. Spectr."},{"key":"B33","doi-asserted-by":"publisher","DOI":"10.1111\/1751-7915.70412","article-title":"WC1\/WC2-Sre1 transcriptional cascade controls predation and chlamydospore formation in the nematode-trapping fungus Arthrobotrys flagrans","volume":"19","author":"Zhang","year":"2026","journal-title":"Microb. Biotechnol."},{"key":"B34","doi-asserted-by":"publisher","DOI":"10.1016\/j.foodres.2025.116580","article-title":"Progress on glycogen branching enzymes and their application in the preparation of highly branched starch: a review","volume":"213","author":"Zhu","year":"2025","journal-title":"Food Res. Int."}],"container-title":["Frontiers in Cellular and Infection Microbiology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fcimb.2026.1891167\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,7]],"date-time":"2026-10-07T04:48:52Z","timestamp":1791348532000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fcimb.2026.1891167\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,7]]},"references-count":34,"alternative-id":["10.3389\/fcimb.2026.1891167"],"URL":"https:\/\/doi.org\/10.3389\/fcimb.2026.1891167","relation":{},"ISSN":["2235-2988"],"issn-type":[{"value":"2235-2988","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,7]]},"article-number":"1891167"}}