Research article - Peer-reviewed, 2021
Comparative analyses of the Hymenoscyphus fraxineus and Hymenoscyphus albidus genomes reveals potentially adaptive differences in secondary metabolite and transposable element repertoires
Elfstrand, Malin; Chen, Jun; Cleary, Michelle; Halecker, Sandra; Ihrmark, Katarina; Karlsson, Magnus; Davydenko, Kateryna; Stenlid, Jan; Stadler, Marc; Durling, Mikael BrandstromAbstract
Background The dieback epidemic decimating common ash (Fraxinus excelsior) in Europe is caused by the invasive fungus Hymenoscyphus fraxineus. In this study we analyzed the genomes of H. fraxineus and H. albidus, its native but, now essentially displaced, non-pathogenic sister species, and compared them with several other members of Helotiales. The focus of the analyses was to identify signals in the genome that may explain the rapid establishment of H. fraxineus and displacement of H. albidus. Results The genomes of H. fraxineus and H. albidus showed a high level of synteny and identity. The assembly of H. fraxineus is 13 Mb longer than that of H. albidus', most of this difference can be attributed to higher dispersed repeat content (i.e. transposable elements [TEs]) in H. fraxineus. In general, TE families in H. fraxineus showed more signals of repeat-induced point mutations (RIP) than in H. albidus, especially in Long-terminal repeat (LTR)/Copia and LTR/Gypsy elements. Comparing gene family expansions and 1:1 orthologs, relatively few genes show signs of positive selection between species. However, several of those did appeared to be associated with secondary metabolite genes families, including gene families containing two of the genes in the H. fraxineus-specific, hymenosetin biosynthetic gene cluster (BGC). Conclusion The genomes of H. fraxineus and H. albidus show a high degree of synteny, and are rich in both TEs and BGCs, but the genomic signatures also indicated that H. albidus may be less well equipped to adapt and maintain its ecological niche in a rapidly changing environment.Keywords
Ash dieback; Viridiol; Fraxinus excelsior; Transposable elements; Secondary metabolites; invasive speciesPublished in
BMC Genomics2021, volume: 22, number: 1, article number: 503
Publisher: BMC
Authors' information
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology
Chen, Jun
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology
Chen, Jun
Zhejiang University
Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre
Halecker, Sandra
Helmholtz Association
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology
Ukrainian Research Institute of Forestry & Forest Melioration
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology
Stadler, Marc
Helmholtz Association
Swedish University of Agricultural Sciences, Department of Forest Mycology and Plant Pathology
UKÄ Subject classification
Genetics
Publication Identifiers
DOI: https://doi.org/10.1186/s12864-021-07837-2
URI (permanent link to this page)
https://res.slu.se/id/publ/113097