Scientists Engineer Crops to Consume More Carbon Dioxide

Scientists have engineered sugarcane and sorghum to take advantage of rising levels of carbon dioxide, allowing these crops to grow bigger.

To achieve this, researchers focused on the enzyme Rubisco. Plants deploy Rubisco to help capture carbon dioxide for use in photosynthesis. But sometimes Rubisco can consume oxygen instead, slowing growth. As humans pump more carbon dioxide into the atmosphere, Rubisco works more efficiently, helping capture more carbon dioxide, which helps plants grow faster.

Rising carbon dioxide levels haven’t yielded the same benefits for all plants, however. A small number of plants are already highly efficient, having evolved a pump that concentrates carbon dioxide in their cells. Such plants — which include corn, sugarcane, and sorghum — are limited less by the amount of carbon dioxide in the air than by the amount of Rubisco in their leaves.

For a new study, scientists targeted these plants, tweaking their genes to produce more Rubisco, New Scientist reported. Scientists had already shown that doing so would speed the growth of corn in the lab. The new research looks at the impact on sorghum grown outdoors, finding that the added Rubisco boosted its growth by 16 percent, on average. The effect was even larger in sugarcane grown in greenhouses, according to the study, which has not yet been peer reviewed.

Said lead author Coralie Salesse-Smith, of the University of Illinois, “I think improving photosynthesis, and Rubisco specifically, will be an important way to cope with food demand in the future.”