Fay-Wei Li, Cornell UniversityFollow
Paul Brouwer, Utrecht University
Lorenzo Carretero-Paulet, Ghent University
Shifeng Cheng, BGI-Shenzhen
Jan de Vries, Dalhousie University
Pierre-Marc Delaux, Université de Toulouse
Ariana Eily, Duke University
Nils Koppers, Heinrich Heine University Düsseldorf
Li-Yaung Kuo, Boyce Thompson Institute
Zheng Li, University of Arizona
Mathew Simenc, California State University
Ian Small, The University of Western Australia
Eric Wafula, Pennsylvania State University
Stephany Angarita, California State University
Michael S. Barker, University of Arizona
Andrea Bräutigam, Bielefeld University
Claude dePamphilis, Pennsylvania State University
Sven Gould, Heinrich Heine University Düsseldorf
Prashant S. Hosmani, Boyce Thompson Institute
Yao-Moan Huang, Taiwan Forestry Research Institute
Bruno Huettel, Max Planck Institute for Plant Breeding
Yoichiro Kato, University of Tokyo
Xin Liu, BGI-Shenzhen
Steven Maere, Ghent University
Rose McDowell, The University of Western Australia
Lukas A. Mueller, Boyce Thompson Institute
Klaas G. J. Nierop, Utrecht University
Stefan A. Rensing, University of Marburg
Tanner A. Robison, Utah State UniversityFollow
Carl J. Rothfels, University of California
Erin M. Sigel, University of Louisiana
Yue Song, BGI-Shenzhen
Prakash R. Timilsena, Pennsylvania State University
Yves Van de Peer, Ghent University
Hongli Wang, BGI-Shenzhen
Per K. I. Wilhelmsson, University of Marburg
Paul G. Wolf, Utah State UniversityFollow
Xun Xu, BGI-Shenzhen
Joshua P. Der, California State University
Henriette Schluepmann, Utrecht University
Gane K.-S. Wong, University of Alberta
Kathleen M. Pryer, Duke University

Document Type


Journal/Book Title/Conference

Nature Plants




Springer Nature

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Ferns are the closest sister group to all seed plants, yet little is known about their genomes other than that they are generally colossal. Here, we report on the genomes of Azolla filiculoides and Salvinia cucullata (Salviniales) and present evidence for episodic whole-genome duplication in ferns—one at the base of ‘core leptosporangiates’ and one specific to Azolla. One fern-specific gene that we identified, recently shown to confer high insect resistance, seems to have been derived from bacteria through horizontal gene transfer. Azolla coexists in a unique symbiosis with N2-fixing cyanobacteria, and we demonstrate a clear pattern of cospeciation between the two partners. Furthermore, the Azolla genome lacks genes that are common to arbuscular mycorrhizal and root nodule symbioses, and we identify several putative transporter genes specific to Azolla–cyanobacterial symbiosis. These genomic resources will help in exploring the biotechnological potential of Azolla and address fundamental questions in the evolution of plant life.