Green Algae Could Hold Clues for Engineering Faster-Growing Crops

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Two new studies of green algae — the scourge of swimming pool owners and freshwater ponds — have revealed new insights into how these organisms siphon carbon dioxide from the air for use in photosynthesis, a key factor in their ability to grow so quickly. Understanding this process may someday help researchers improve the growth rate of crops such as wheat and rice.

Two new studies of green algae — the scourge of swimming pool owners and freshwater ponds — have revealed new insights into how these organisms siphon carbon dioxide from the air for use in photosynthesis, a key factor in their ability to grow so quickly. Understanding this process may someday help researchers improve the growth rate of crops such as wheat and rice.

In the studies published this week in the journal Cell, the Princeton-led team reported the first detailed inventory of the cellular machinery — located in an organelle known as the pyrenoid —  that algae use to collect and concentrate carbon dioxide. The researchers also found that the pyrenoid, long thought to be a solid structure, actually behaves like a liquid droplet that can dissolve into the surrounding cellular medium when the algal cells divide.

“Understanding how algae can concentrate carbon dioxide is a key step toward the goal of improving photosynthesis in other plants,” said Martin Jonikas, an assistant professor of molecular biology at Princeton and leader of the studies, which included collaborators at the Max Planck Institute of Biochemistry in Germany and the Carnegie Institution for Science on the Stanford University campus. “If we could engineer other crops to concentrate carbon, we could address the growing world demand for food,” Jonikas said.

Aquatic algae and a handful of other plants have developed carbon-concentrating mechanisms that boost the rate of photosynthesis, the process by which plants turn carbon dioxide and sunlight into sugars for growth. All plants use an enzyme called Rubisco to “fix” carbon dioxide into sugar that can be used or stored by the plant.

Read more at Princeton University

Image: Two new Princeton-led studies provide a detailed look at an essential part of algae's growth machinery, with the eventual goal of applying this knowledge to improving the growth of crops. In this image, the researchers used a technique called cryo-electron tomography to image an algal structure called the pyrenoid, which concentrates carbon dioxide to make it more readily available for photosynthetic enzymes (purple). The yellow tubules inside the green tubes are thought to bring carbon and other materials into the pyrenoid. (Credit: Image courtesy of Benjamin Engel, Max Planck Institute of Biochemistry)