---
title: "MpSDR4 in liverworts modulates abscisic acid sensitivity and promotes gemma cup growth"
id: "biorxiv-16-liverwort-mpsdr4-regulates-abscisic-acid-sensitivity-and-gemma-cup-growth"
canonical_url: "https://medichelpline.com/clinical-feed/biorxiv-16-liverwort-mpsdr4-regulates-abscisic-acid-sensitivity-and-gemma-cup-growth"
content_type: "clinical_feed_article"
specialty: "General"
source_name: "bioRxiv (Biomedical Preprints)"
source_url: "https://www.biorxiv.org/content/10.64898/2026.10.21.760454v1?rss=1"
published_at: "2026-10-23T12:00:00.000Z"
evidence_level: "Verified Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# MpSDR4 in liverworts modulates abscisic acid sensitivity and promotes gemma cup growth
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/biorxiv-16-liverwort-mpsdr4-regulates-abscisic-acid-sensitivity-and-gemma-cup-growth
- **Specialty:** [General](https://medichelpline.com/clinical-feed/general.md)
- **Primary Source:** bioRxiv (Biomedical Preprints)
- **Source URL:** [Original Journal Publication](https://www.biorxiv.org/content/10.64898/2026.10.21.760454v1?rss=1)
- **Published At:** 2026-10-23T12:00:00.000Z
- **Evidence Rating:** Verified Feed
## Executive GIST (TL;DR)
- Investigators used a structure-informed molecular phylogenetic analysis to trace the evolutionary history of the **SDR4** family, identifying a major gene duplication event preceding seed-plant origins. - The duplication produced two paralogous clades named **SDR4** and DIG/DIL, which the study team observed are broadly retained across seed plants. - Marchantia polymorpha carries a single **MpSDR4** homolog; the authors generated loss-of-function **Mpsdr4** mutants to probe ancestral SDR4 roles in a seed-free model. - The cohort of mutant plants showed altered sensitivity to the phytohormone **abscisic acid (ABA)**, indicating that MpSDR4 modulates hormone responses linked to germination-related processes in other lineages. - Transcriptome profiling performed by the study team indicated differential expression patterns consistent with changes in ABA responsiveness; the abstract does not specify the genes or pathways differentially regulated. - The **Mpsdr4** mutants displayed increased growth of **gemma cups**, a vegetative reproductive structure in liverworts, revealing a role for this gene in asexual reproduction distinct from seed-plant phenotypes. - Data indicated functional divergence of SDR4 orthologs between monocots and eudicots in flowering plants; the authors suggested SDR4 acquired roles in seed dormancy and germination regulation after the duplication event. - The preprint status was declared; the abstract does not provide experimental details such as mutant generation methods, ABA concentrations used, sample sizes, or statistical endpoints—those specifics were not reported in the abstract.
## Clinical Analysis & Structured Key Points
Liverwort MpSDR4 regulates abscisic acid sensitivity and gemma cup growth | bioRxiv Skip to main content New Results Liverwort MpSDR4 regulates abscisic acid sensitivity and gemma cup growth View ORCID Profile Jiayi Shan , View ORCID Profile Jay Mie Kua , View ORCID Profile Janty Woojuh , View ORCID Profile Sean Cutler , View ORCID Profile Sean W. Graham , View ORCID Profile Liang Song doi: https://doi.org/10.64898/2026.10.21.760454 Jiayi Shan 1 University of British Columbia; Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Jiayi Shan Jay Mie Kua 1 University of British Columbia; Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Jay Mie Kua Janty Woojuh 2 University of California, Riverside Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Janty Woojuh Sean Cutler 2 University of California, Riverside Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Sean Cutler Sean W. Graham 1 University of British Columbia; Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Sean W. Graham Liang Song 1 University of British Columbia; Find this author on Google Scholar Find this author on PubMed Search for this author on this site ORCID record for Liang Song For correspondence: liang.song{at}botany.ubc.ca Abstract Info/History Metrics Supplementary material Preview PDF Abstract Complex traits often evolve by co-opting pre-existing genetic components. Orthologs of the transcriptional co-factor SEED DORMANCY 4 (SDR4) are found across seed-bearing and seed-free land plants. In flowering plants, loss-of-function mutants of sdr4 orthologs in rice and Arabidopsis exhibit opposite phenotypes in seed germination, a trait regulated by the phytohormone abscisic acid (ABA). We uncovered a major gene duplication event that closely preceded the origin of seed plants, by using a structure-informed molecular phylogenetic analysis. This duplication gave rise to the paralogous SDR4 and DIG/DIL clades, which are broadly retained across the seed plants. Investigating the role of SDR4 homologs in the common liverwort Marchantia polymorpha, a seed-free model organism with only a single SDR4-like homolog (MpSDR4), may provide insights into how SDR4 evolved to regulate dormancy and germination in other land plants. Loss-of-function mutants of Mpsdr4 and transcriptome profiling showed that MpSDR4 modulates ABA sensitivity, consistent with the idea that SDR4 subsequently evolved to regulate hormone responses related to seed germination, with additional functional divergence between monocots and eudicots. Furthermore, Mpsdr4 mutants exhibit elevated growth of gemma cups, contrasting the roles of SDR4 orthologs in asexual reproduction in liverwort with the regulation of seed traits in flowering plants. Competing Interest Statement The authors have declared no competing interest. Funder Information Declared Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant , NSERC RGPIN-2026-07568 Canada Foundation for Innovation John R. Evans Leaders Fund award matched by the British Columbia Knowledge Development Fund , CFI JELF/BCKDF 38187 Copyright The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC 4.0 International license . Back to top Previous Next Posted October 23, 2026. Download PDF Supplementary Material Email Thank you for your interest in spreading the word about bioRxiv. NOTE: Your email address is requested solely to identify you as the sender of this article. Your Email * Your Name * Send To * Enter multiple addresses on separate lines or separate them with commas. You are going to email the following Liverwort MpSDR4 regulates abscisic acid sensitivity and gemma cup growth Message Subject (Your Name) has forwarded a page to you from bioRxiv Message Body (Your Name) thought you would like to see this page from the bioRxiv website. Your Personal Message CAPTCHA This question is for testing whether or not you are a human visitor and to prevent automated spam submissions. Share Liverwort MpSDR4 regulates abscisic acid sensitivity and gemma cup growth Jiayi Shan , Jay Mie Kua , Janty Woojuh , Sean Cutler , Sean W. Graham , Liang Song bioRxiv 2026.10.21.760454; doi: https://doi.org/10.64898/2026.10.21.760454 Share This Article: Copy Citation Tools Liverwort MpSDR4 regulates abscisic acid sensitivity and gemma cup growth Jiayi Shan , Jay Mie Kua , Janty Woojuh , Sean Cutler , Sean W. Graham , Liang Song bioRxiv 2026.10.21.760454; doi: https://doi.org/10.64898/2026.10.21.760454 Citation Manager Formats BibTeX Bookends EasyBib EndNote (tagged) EndNote 8 (xml) Medlars Mendeley Papers RefWorks Tagged Ref Manager RIS Zotero Tweet Widget Facebook Like Google Plus One Subject Areas All Articles Animal Behavior and Cognition (8164) Biochemistry (19027) Bioengineering (15171) Bioinformatics (45323) Biophysics (22958) Cancer Biology (20106) Cell Biology (27293) Clinical Trials (138) Developmental Biology (14142) Ecology (21393) Epidemiology (2067) Evolutionary Biology (25782) Genetics (16342) Genomics (23827) Immunology (19017) Microbiology (43178) Molecular Biology (18335) Neuroscience (95039) Paleontology (712) Pathology (3031) Pharmacology and Toxicology (5197) Physiology (8278) Plant Biology (16266) Scientific Communication and Education (2115) Synthetic Biology (4643) Systems Biology (10382) Zoology (2426)
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