Scientists have uncovered a unique modification in a key plant enzyme that could dramatically improve photosynthesis and increase crop yields, offering a promising breakthrough for global agriculture.
At the centre of this discovery is Rubisco, the enzyme responsible for capturing carbon dioxide and converting it into energy-rich sugars during photosynthesis. While essential for plant life, Rubisco is notoriously inefficient because it often reacts with oxygen instead of carbon dioxide. This mistake produces a toxic byproduct and forces plants to expend extra energy through a process called photorespiration, ultimately reducing growth and productivity.
Researchers studying hornworts, a group of simple land plants, have now identified a completely new way to improve Rubisco’s efficiency. In the species Anthoceros fusiformis, the enzyme contains a previously unknown structural extension that helps cluster Rubisco molecules together. This clustering reduces contact with oxygen and enhances the plant’s ability to fix carbon dioxide more effectively.
Unlike algae, which use separate linker proteins to organise Rubisco into specialised structures called pyrenoids, hornworts achieve a similar outcome through this built-in modification. The newly discovered version of the enzyme, named RbcS-STAR, forms coiled structures that bring multiple Rubisco units into close proximity, creating a more efficient system for photosynthesis.
To test its potential, scientists successfully introduced this modification into Arabidopsis thaliana, a widely used model for crop research. The results were striking. The engineered plants not only produced functional Rubisco but also developed pyrenoid-like structures inside their cells, a feature that could significantly enhance photosynthetic performance.
Previous studies suggest that such carbon-concentrating mechanisms can increase photosynthetic efficiency by 30 to 60 percent. In practical terms, this could translate into faster-growing crops with higher yields, an outcome that is especially important as global food demand continues to rise under the pressures of climate change.
However, researchers caution that this is only part of the solution. While the structural “framework” for improved photosynthesis has been created, plants will also need systems to deliver higher concentrations of carbon dioxide to these structures for maximum benefit. Scientists describe this as building the “house” for efficiency, but still needing to install the “system” that makes it fully functional.
Despite these challenges, the discovery marks a major step forward in plant science and biotechnology. By borrowing and adapting natural innovations from simpler plants like hornworts, scientists are opening new pathways to engineer crops that are more productive, resilient and better suited to a changing climate.
If successfully applied to staple crops such as rice or wheat, this breakthrough could play a critical role in strengthening global food security in the decades ahead.