The Spirogyra pratensis genome illuminates the evolution of developmental programs and spiral chloroplast biology

Year: 2026

Type: article

Abstract: Zygnematophytes emerged as the unexpected closest algal relatives of land plants despite their simple body plans, raising questions about the morphogenetic toolkit present in the last common ancestor of land plants and algae. Genomic analyses have revealed that zygnematophytes are cellular giants, sharing homologous frameworks for several phytohormones, secondary metabolites, and key morphogenetic and transcriptional regulatory processes. Zygnematophytes fall into 5 orders, each of which has charted its own evolutionary path. Here, we have sequenced a contiguous genome of Spirogyra pratensis, the eponymous representative of Spirogyrales and a classical model system for evolutionary cell biology in the green lineage. Building on this genome, we transcriptionally profiled the tractable life cycle of Spirogyra and its responses to a bifactorial gradient of light and temperature. Our data highlight the activation of quiescence and homeostatic programs. Yet what stands out most in Spirogyra is its spiral chloroplast-undulating intracellularly and abscising during mixed phragmoplast formation and furrowing. Leveraging the genome in tandem with co-expression network analyses, we describe the molecular underpinnings of the unique cytokinetic processes that govern both cell and plastid division. We find that Spirogyra deploys a molecular program characteristic of Phragmoplastophyta yet lacks the deeply conserved plastid division machinery found in other archaeplastid plastids.

Source: The Plant Cell

DOI: 10.1093/plcell/koag224

Institutions: Campus-Institut Data Science (CIDAS), University of Göttingen, University of Freiburg, Philipps University of Marburg, Southwest University, Universität Hamburg, Christian-Albrechts-Universität zu Kiel, Universität Innsbruck, Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Düsseldorf University Hospital, Heinrich Heine University Düsseldorf, University of Cologne, Duke University, AgroParisTech, Université Paris-Saclay, Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement, Institut Jean-Pierre Bourgin, Max Planck Institute for Plant Breeding Research, Hochschule Mittweida

Language: English

Topic: Protist diversity and phylogeny

Subfield: Ecology, Evolution, Behavior and Systematics

Field: Agricultural and Biological Sciences

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $4,934

Funders: International Max Planck Research School for Environmental, Cellular and Molecular Microbiology, European Commission, European Science Foundation, Deutsche Forschungsgemeinschaft, Agence Nationale de la Recherche, Austrian Science Fund, Universität Hamburg, Universität Innsbruck, International Max Planck Research School for Advanced Methods in Process and Systems Engineering, China Shipbuilding Industry, European Regional Development Fund, Agencia Estatal de Investigación

OpenAlex ID: W7171590216