Convergent losses of decay mechanisms and rapid turnover of symbiosis genes in mycorrhizal mutualists

• Published in: Nature genetics Vol. 47; no. 4; pp. 410 - 415
• Main Authors: Kohler, Annegret, Kuo, Alan, Nagy, Laszlo G, Morin, Emmanuelle, Barry, Kerrie W, Buscot, Francois, Canbäck, Björn, Choi, Cindy, Cichocki, Nicolas, Clum, Alicia, Colpaert, Jan, Copeland, Alex, Costa, Mauricio D, Doré, Jeanne, Floudas, Dimitrios, Gay, Gilles, Girlanda, Mariangela, Henrissat, Bernard, Herrmann, Sylvie, Hess, Jaqueline, Högberg, Nils, Johansson, Tomas, Khouja, Hassine-Radhouane, LaButti, Kurt, Lahrmann, Urs, Levasseur, Anthony, Lindquist, Erika A, Lipzen, Anna, Marmeisse, Roland, Martino, Elena, Murat, Claude, Ngan, Chew Y, Nehls, Uwe, Plett, Jonathan M, Pringle, Anne, Ohm, Robin A, Perotto, Silvia, Peter, Martina, Riley, Robert, Rineau, Francois, Ruytinx, Joske, Salamov, Asaf, Shah, Firoz, Sun, Hui, Tarkka, Mika, Tritt, Andrew, Veneault-Fourrey, Claire, Zuccaro, Alga, Tunlid, Anders, Grigoriev, Igor V, Hibbett, David S, Martin, Francis
• Format: Journal Article
• Language: English
• Published: New York Nature Publishing Group US 01-04-2015; Nature Publishing Group
• Subjects: 38; 38/91; 45; 45/23; 631/326; Agriculture; Animal Genetics and Genomics; Base Sequence; BASIC BIOLOGICAL SCIENCES; Biologi; Biological Sciences; Biomedicine; Cancer Research; Cellulose; Enzymes; Evolution, Molecular; Evolutionary Biology; Evolutionary genetics; Evolutionsbiologi; Fungi; Gene Deletion; Gene Expression Regulation, Fungal - genetics; Gene Function; Genes; Genetic aspects; Genetic research; Genetics; Genetik; Genome, Fungal - genetics; Genomes; Genomics; Human Genetics; Laboratories; letter; Lignin; Lignocellulose; Molecular Sequence Data; Mycorrhizae - genetics; Mycorrhizae - pathogenicity; Mycorrhizas; Natural Sciences; Naturvetenskap; Phylogeny; Plant Diseases - genetics; Plant Diseases - microbiology; Plant Roots - microbiology; Selection, Genetic; Symbiosis; Symbiosis - genetics; Trees; Virulence - genetics
• ISSN: 1061-4036; 1546-1718; 1546-1718
• DOI: 10.1038/ng.3223

Francis Martin and colleagues report genome sequences for 18 species of mycorrhizal fungi and a phylogenomic analysis including 32 other fungal genomes. The study identifies cell wall-degradation genes lost in all true ectomycorrhizal species and, using gene expression data, finds candidate genes for the establishment of symbiosis.
To elucidate the genetic bases of mycorrhizal lifestyle evolution, we sequenced new fungal genomes, including 13 ectomycorrhizal (ECM), orchid (ORM) and ericoid (ERM) species, and five saprotrophs, which we analyzed along with other fungal genomes. Ectomycorrhizal fungi have a reduced complement of genes encoding plant cell wall–degrading enzymes (PCWDEs), as compared to their ancestral wood decayers. Nevertheless, they have retained a unique array of PCWDEs, thus suggesting that they possess diverse abilities to decompose lignocellulose. Similar functional categories of nonorthologous genes are induced in symbiosis. Of induced genes, 7–38% are orphan genes, including genes that encode secreted effector-like proteins. Convergent evolution of the mycorrhizal habit in fungi occurred via the repeated evolution of a 'symbiosis toolkit', with reduced numbers of PCWDEs and lineage-specific suites of mycorrhiza-induced genes.