The architecture of resilience: a genome assembly of <i>Myrothamnus flabellifolia</i> sheds light on desiccation tolerance and sex determination
Myrothamnus flabellifolia is a dioecious resurrection plant endemic to southern Africa that has become an important model for understanding desiccation tolerance. Despite its ecological and medicinal significance, genomic and transcriptomic resources for the species are limited. We generated a chromosome-level, haplotype-resolved reference genome assembly and annotation for M. flabellifolia and conducted transcriptomic profiling across a natural dehydration-rehydration time course in the field. Genome architecture and sex determination were characterized, and co-expression network and cis-regulatory element (CRE) enrichment analyses were used to investigate dynamic responses to desiccation. The 1.28-Gb genome exhibits unusually consistent chromatin architecture with unique chromosome organization across highly divergent haplotypes. We identified an XY sexual system with a small sex-determining region on Chromosome 8. Transcriptomic responses varied with dehydration severity, pointing to early suppression of growth, progressive activation of protective mechanisms, and subsequent return to homeostasis upon rehydration. Late embryogenesis abundant and early light-induced protein transcripts were dynamically regulated and showed enrichment of abscisic acid and stress-responsive CREs pointing toward conserved responses. Together, this study provides foundational resources for understanding the genomic architecture and reproductive biology of M. flabellifolia and offers new insights into the mechanisms of desiccation tolerance.
Authors
- Diane Bauer (ORCID: https://orcid.org/0000-0002-3660-4629)
- Robert VanBuren (ORCID: https://orcid.org/0000-0003-2133-2760)
- John T. Lovell (ORCID: https://orcid.org/0000-0002-8938-1166)
- Sarah B. Carey
- Kerrie Barry (ORCID: https://orcid.org/0000-0002-8999-6785)
- Jayson Talag (ORCID: https://orcid.org/0000-0001-6085-214X)
- Jill M. Farrant (ORCID: https://orcid.org/0000-0002-1450-7967)
- Anna Lipzen (ORCID: https://orcid.org/0000-0003-2293-9329)
- Jerry Jenkins (ORCID: https://orcid.org/0000-0002-7943-3997)
- Joanne Bentley (ORCID: https://orcid.org/0000-0003-0691-0323)
- Juying Yan (ORCID: https://orcid.org/0000-0003-0079-4800)
- Jim Leebens‐Mack (ORCID: https://orcid.org/0000-0003-4811-2231)
- Jane Grimwood (ORCID: https://orcid.org/0000-0002-8356-8325)
- Jeremy Schmutz (ORCID: https://orcid.org/0000-0001-8062-9172)
- Llewelyn Van Der Pas (ORCID: https://orcid.org/0000-0002-4007-5811)
- Alex Harkess (ORCID: https://orcid.org/0000-0002-2035-0871)
- Jenell Webber (ORCID: https://orcid.org/0009-0005-6155-6218)
- Nyaradzai M. Chimukuche (ORCID: https://orcid.org/0000-0002-1604-1531)
- Christopher Plott (ORCID: https://orcid.org/0000-0002-0109-5174)
- Chloee M. McLaughlin (ORCID: https://orcid.org/0000-0002-6345-6764)
- Tomáš Brůna (ORCID: https://orcid.org/0000-0001-9811-5532)
- Rose A. Marks (ORCID: https://orcid.org/0000-0001-7102-5959)
Institutions
- Translational Genomics Research Institute (US)
- University of Arizona (US)
- Lawrence Berkeley National Laboratory (US)
- University of Cape Town (ZA)
- University of Illinois Urbana-Champaign (US)
- University of Georgia (US)
- Joint Genome Institute (US)
- Carnegie Department of Plant Biology (US)
- HudsonAlpha Institute for Biotechnology (US)
- Michigan State University (US)
Publication Details
- Journal
- New Phytologist
- Published
- 2025-11-02
- DOI
- https://doi.org/10.1111/nph.70700
- Primary Topic
- Plant Molecular Biology Research
- Type
- article
- Field-Weighted Citation Impact
- 0.00