title: A lectin-mediated resistance of higher fungi against predators and parasites.
abstract: Fruiting body lectins are ubiquitous in higher fungi and characterized by being synthesized in the cytoplasm and up-regulated during sexual development. The function of these lectins is unclear. A lack of phenotype in sexual development upon inactivation of the respective genes argues against a function in this process. We tested a series of characterized fruiting body lectins from different fungi for toxicity towards the nematode Caenorhabditis elegans, the mosquito Aedes aegypti and the amoeba Acanthamoeba castellanii. Most of the fungal lectins were found to be toxic towards at least one of the three target organisms. By altering either the fungal lectin or the glycans of the target organisms, or by including soluble carbohydrate ligands as competitors, we demonstrate that the observed toxicity is dependent on the interaction between the fungal lectins and specific glycans in the target organisms. The toxicity was found to be dose-dependent such that low levels of lectin were no longer toxic but still led to food avoidance by C. elegans. Finally, we show, in an ecologically more relevant scenario, that challenging the vegetative mycelium of Coprinopsis cinerea with the fungal-feeding nematode Aphelenchus avenae induces the expression of the nematotoxic fruiting body lectins CGL1 and CGL2. Based on these findings, we propose that filamentous fungi possess an inducible resistance against predators and parasites mediated by lectins that are specific for glycans of these antagonists.
authors.affiliation: Institute of Microbiology, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, CH-8093, Zürich, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Bleuler-Martínez
authors.forename: A
authors.initials: A
authors.lastname: Butschi
authors.forename: M
authors.initials: M
authors.lastname: Garbani
authors.forename: M A
authors.initials: MA
authors.lastname: Wälti
authors.forename: T
authors.initials: T
authors.lastname: Wohlschlager
authors.forename: E
authors.initials: E
authors.lastname: Potthoff
authors.forename: J
authors.initials: J
authors.lastname: Sabotiĉ
authors.forename: J
authors.initials: J
authors.lastname: Pohleven
authors.forename: P
authors.initials: P
authors.lastname: Lüthy
authors.forename: M O
authors.initials: MO
authors.lastname: Hengartner
authors.forename: M
authors.initials: M
authors.lastname: Aebi
authors.forename: M
authors.initials: M
authors.lastname: Künzler
mesh_terms: D048248:Acanthamoeba castellanii / Q000187:drug effects; D000330:Aedes / Q000187:drug effects; D000818:Animals; D017173:Caenorhabditis elegans / Q000187:drug effects; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005247:Feeding Behavior; D048690:Fruiting Bodies, Fungal / Q000737:chemistry*; D005656:Fungal Proteins / Q000633:toxicity*; D005658:Fungi / Q000737:chemistry*; D037102:Lectins / Q000633:toxicity*; D025282:Mycelium / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D037102:Lectins; D011134:Polysaccharides