On the way to diploidization and unexpected ploidy in the grass Sporobolus section Spartina mesopolyploids
Plant history is characterized by cyclical whole genome duplication and diploidization with important biological and ecological consequences. Here, we explore the genome history of two related iconic polyploid grasses (Sporobolus alterniflorus and S. maritimus), involved in a well-known example of neopolyploid speciation. We report particular genome dynamics where an ancestral Sporobolus genome (n = 2x = 20) duplicated 9.6-24.4 million years ago (MYA), which was followed by descending dysploidy resulting in a genome with an unexpected base chromosome number (n = 15). This diploidized genome duplicated again 2.1-6.2 MYA to form a tetraploid lineage (2n = 4x = 60), thus reshuffling the ploidy of these species previously thought hexaploids. We also elucidate the mechanism accompanying the speciation between S. maritimus (2n = 60) and S. alterniflorus (2n = 62), resulting from chromosome restructuring, and identify key adaptive genes in the corresponding regions. This represents critical findings to decipher molecular mechanisms underlying species expansion, adaptation to environmental challenge and invasiveness.
Authors
- Armand Cavé‐Radet (ORCID: https://orcid.org/0000-0001-9254-4993)
- Patrick Wincker (ORCID: https://orcid.org/0000-0001-7562-3454)
- Karine Labadie (ORCID: https://orcid.org/0000-0001-7467-8509)
- Armel Salmon (ORCID: https://orcid.org/0000-0003-4479-0801)
- Caroline Belser (ORCID: https://orcid.org/0000-0002-8108-9910)
- Benjamin Istace (ORCID: https://orcid.org/0000-0003-1042-4803)
- Corinne Cruaud (ORCID: https://orcid.org/0000-0002-4752-7278)
- Malika L. Aïnouche (ORCID: https://orcid.org/0009-0004-6979-3405)
- Delphine Giraud (ORCID: https://orcid.org/0000-0002-1563-0123)
- Jean‐Marc Aury (ORCID: https://orcid.org/0000-0003-1718-3010)
- Bo Li (ORCID: https://orcid.org/0000-0002-0439-5666)
- Hao Yan (ORCID: https://orcid.org/0009-0009-0593-7410)
- Oscar Lima
- Linfeng Li (ORCID: https://orcid.org/0000-0003-2820-3187)
- Morgane Milin (ORCID: https://orcid.org/0009-0005-2853-5511)
Institutions
- Centre National de la Recherche Scientifique (FR)
- Sun Yat-sen University (CN)
- Yunnan University (CN)
- Fudan University (CN)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Université Paris-Saclay (FR)
- Ecosystèmes, Biodiversité, Evolution (FR)
- Genoscope (FR)
- Ministry of Natural Resources (RW)
- CEA Paris-Saclay (FR)
- Université de Rennes (FR)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-02-26
- DOI
- https://doi.org/10.1038/s41467-025-56983-8
- Citations
- 3
- Primary Topic
- Chromosomal and Genetic Variations
- Type
- article
- Field-Weighted Citation Impact
- 5.25
Funders
- Agence Nationale de la Recherche
- National Natural Science Foundation of China
- Fudan University
- Centre National de la Recherche Scientifique
- Yunnan Provincial Science and Technology Department
- National Key Research and Development Program of China