An unconventional Rubisco small subunit underpins the CO 2 -concentrating organelle in land plants
Abstract
In many algae, photosynthesis is boosted by biophysical CO 2 -concentrating mechanisms, which pack the CO 2 -fixing enzyme Rubisco into liquid-like organelles called pyrenoids. Engineering C 3 crops with algal pyrenoids could increase yields, but progress is hampered by the deep evolutionary divide between crops and algae. Here, we show that hornworts, the only land plants with pyrenoids, have an unusual Rubisco small subunit, RbcS-STAR, the C-terminal coiled-coil domain of which oligomerizes to mediate Rubisco condensation. RbcS-STAR is incorporated into the Rubisco holoenzyme and thus acts as an “innate” Rubisco linker. Expression of RbcS-STAR in pyrenoid-lacking species, including Arabidopsis , is sufficient to induce pyrenoid-like condensates. Our findings reveal a mechanism for Rubisco condensation and a potential route to introduce pyrenoids into crop plants.
Fields of Study & Subjects
Photosynthetic Processes and Mechanisms
Lipid metabolism and biosynthesis
Insect-Plant Interactions and Control
Publication details
- Journal / source
- Science
- Publisher
- American Association for the Advancement of Science (AAAS)
- Volume
- 391
- Issue
- 6789
- Pages
- 1070–1075
- Publication date
- 5 March 2026
- Language
- EN