The green algae CO2 concentrating mechanism and photorespiration jointly operate during acclimation to low CO2
Due to low availability of CO<sub>2</sub> in aquatic environment, microalgae have evolved a CO<sub>2</sub> concentrating mechanism (CCM). It has long been thought that operation of CCM would suppress photorespiration by increasing the CO<sub>2</sub> concentration at the Rubisco active site, but experimental evidence is scarce. To better explore the function of photorespiration in algae, we first characterized a Chlamydomonas reinhardtii mutant defected in low-CO<sub>2</sub> inducible 20 (LCI20) and show that LCI20 is a chloroplast-envelope glutamate/malate transporter playing a role in photorespiration. By monitoring growth and glycolate excretion in mutants deficient in either CCM or photorespiration, we conclude that: (i.) CCM induction does not depend on photorespiration, (ii.) glycolate excretion together with glycolate dehydrogenase down-regulation prevents the toxic accumulation of non-metabolized photorespiratory metabolites, and (iii.) photorespiration is active at low CO<sub>2</sub> when the CCM is operational. This work provides a foundation for a better understanding of the carbon cycle in the ocean where significant glycolate concentrations have been found.
Authors
- Saleh Alseekh (ORCID: https://orcid.org/0000-0003-2067-5235)
- Caroline Monteil (ORCID: https://orcid.org/0000-0002-2834-6834)
- Adrien Burlacot (ORCID: https://orcid.org/0000-0001-7434-6416)
- Virginie Epting (ORCID: https://orcid.org/0000-0001-6561-8432)
- Luke C. M. Mackinder (ORCID: https://orcid.org/0000-0003-1440-3233)
- Florian Veillet (ORCID: https://orcid.org/0000-0002-6892-6825)
- Amélie Morin (ORCID: https://orcid.org/0000-0003-3318-8778)
- Anja Krieger‐Liszkay (ORCID: https://orcid.org/0000-0001-7141-4129)
- Stéphan Cuiné (ORCID: https://orcid.org/0000-0002-3000-3355)
- Andreas P.M. Weber (ORCID: https://orcid.org/0000-0003-0970-4672)
- Ousmane Dao (ORCID: https://orcid.org/0000-0002-7040-5770)
- Bertrand Légeret (ORCID: https://orcid.org/0000-0002-0957-4700)
- Pascaline Auroy (ORCID: https://orcid.org/0000-0002-3376-6550)
- Alisdair Robert Fernie (ORCID: https://orcid.org/0000-0001-9000-335X)
- Gilles Peltier (ORCID: https://orcid.org/0000-0002-2226-3931)
- Marie Bertrand (ORCID: https://orcid.org/0000-0001-5098-1554)
- Yonghua Li‐Beisson (ORCID: https://orcid.org/0000-0003-1064-1816)
- Phuong-Chi Nguyen
Institutions
- Centre National de la Recherche Scientifique (FR)
- Carnegie Institution for Science (US)
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives (FR)
- Université Paris-Saclay (FR)
- Center of Plant Systems Biology and Biotechnology (BG)
- Max Planck Institute of Molecular Plant Physiology (DE)
- Institut de Biologie Intégrative de la Cellule (FR)
- CEA Cadarache (FR)
- Cluster of Excellence on Plant Sciences (DE)
- CEA Paris-Saclay (FR)
- Institut de Biosciences et Biotechnologies (FR)
- Heinrich Heine University Düsseldorf (DE)
- University of York (GB)
- Stanford University (US)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-06-17
- DOI
- https://doi.org/10.1038/s41467-025-60525-7
- Citations
- 7
- Primary Topic
- Algal biology and biofuel production
- Type
- article
- Field-Weighted Citation Impact
- 2.54
Funders
- Carnegie Institution of Washington
- European Commission
- Deutsche Forschungsgemeinschaft
- Agence Nationale de la Recherche
- Max-Planck-Gesellschaft
- Commissariat à l'Énergie Atomique et aux Énergies Alternatives
- French Infrastructure for Integrated Structural Biology
- Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
- Horizon 2020 Framework Programme
- European Regional Development Fund