title: Identification of a Novel Nematotoxic Protein by Challenging the Model Mushroom Coprinopsis cinerea with a Fungivorous Nematode.
abstract: The dung of herbivores, the natural habitat of the model mushroom Coprinopsis cinerea, is a nutrient-rich but also very competitive environment for a saprophytic fungus. We showed previously that C. cinerea expresses constitutive, tissue-specific armories against antagonists such as animal predators and bacterial competitors. In order to dissect the inducible armories against such antagonists, we sequenced the poly(A)-positive transcriptome of C. cinerea vegetative mycelium upon challenge with fungivorous and bacterivorous nematodes, Gram-negative and Gram-positive bacteria and mechanical damage. As a response to the fungivorous nematode Aphelenchus avenae, C. cinerea was found to specifically induce the transcription of several genes encoding previously characterized nematotoxic lectins. In addition, a previously not characterized gene encoding a cytoplasmic protein with several predicted Ricin B-fold domains, was found to be strongly upregulated under this condition. Functional analysis of the recombinant protein revealed a high toxicity toward the bacterivorous nematode Caenorhabditis elegans. Challenge of the mycelium with A. avenae also lead to the induction of several genes encoding putative antibacterial proteins. Some of these genes were also induced upon challenge of the mycelium with the bacteria Escherichia coli and Bacillus subtilis. These results suggest that fungi have the ability to induce specific innate defense responses similar to plants and animals.
authors.affiliation: Institute of Microbiology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: David Fernando
authors.initials: DF
authors.lastname: Plaza
authors.affiliation: Institute of Microbiology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland.
authors.forename: Stefanie Sofia
authors.initials: SS
authors.lastname: Schmieder
authors.affiliation: Genomic Technologies, Joint Genome Institute, Walnut Creek, California 94598.
authors.forename: Anna
authors.initials: A
authors.lastname: Lipzen
authors.affiliation: Genomic Technologies, Joint Genome Institute, Walnut Creek, California 94598.
authors.forename: Erika
authors.initials: E
authors.lastname: Lindquist
authors.affiliation: Institute of Microbiology, Department of Biology, ETH Zürich, 8093 Zürich, Switzerland mkuenzle@ethz.ch.
authors.forename: Markus
authors.initials: M
authors.lastname: Künzler
mesh_terms: D000363:Agaricales / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D000898:Antibiosis; D019295:Computational Biology / Q000379:methods; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D059014:High-Throughput Nucleotide Sequencing; D009348:Nematoda; D013312:Stress, Physiological / Q000235:genetics; D059467:Transcriptome
chemical_list: D005656:Fungal Proteins
keywords: CCTX2; RNA sequencing; basidiomycete; fungal defense; transcriptomics