Small RNAs regulation and genomic harmony: insights into allopolyploid evolution in marsh orchids (Dactylorhiza)

Hybridization and polyploidy are major drivers of plant diversification, often accompanied by shifts in gene expression and genome composition. Small RNAs (smRNAs) are thought to influence such genomic changes, particularly through their interactions with transposable elements (TEs). We quantified s...

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Detalles Bibliográficos
Autores: Eriksson, Mimmi C., Thornton, Matthew, Trucchi, Emiliano, Wolfe, Thomas M., Balao Robles, Francisco J., Hedrén, Mikael, Paun, Ovidiu
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2026
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:dnet:idus________::c898f0274b961596c4c555ff30ba7d33
Acceso en línea:https://hdl.handle.net/11441/184327
https://doi.org/10.1111/nph.70966
Access Level:acceso abierto
Palabra clave:Allopolyploidy
Dactylorhiza
Gene regulation
Marsh orchids
Small RNAs
Subgenome dominance
Transposable elements
Descripción
Sumario:Hybridization and polyploidy are major drivers of plant diversification, often accompanied by shifts in gene expression and genome composition. Small RNAs (smRNAs) are thought to influence such genomic changes, particularly through their interactions with transposable elements (TEs). We quantified smRNAs in established sibling allopolyploids Dactylorhiza majalis and D. traunsteineri and their diploid progenitors to assess how independent allopolyploidization events shaped smRNA landscapes. Despite independent origins, the allotetraploids exhibited substantial overlap in smRNA composition, including transgressive accumulation of smRNAs near genes related to transcriptional regulation, cell division, and stress response. Consistently, TE-associated 24 nt smRNAs more closely resembled the paternal and larger genome, while shorter smRNAs typically reflected the maternal and smaller genome. Nevertheless, distinct patterns were also evident: the older D. majalis showed greater accumulation of smRNAs near genes involved in transcriptional and translational regulation, while the younger D. traunsteineri displayed stronger non-additive patterns, suggesting ongoing resolution of post-polyploid meiotic and mitotic instability. Our results reveal both convergence and divergence in smRNA landscapes among independently formed allopolyploids. Our study highlights the central role of smRNAs in resolving genomic conflict, with possible implications for functional divergence and ecological innovation during polyploid evolution.