Bioengineering: better photosynthesis increases crop yield

Springfield, US - For the first time, researchers have proven that multigene bioengineering of photosynthesis increases the yield of a major food crop in field trials.

After more than a decade of working toward this goal, a collaborative team led by the University of Illinois has transgenically altered soybean plants to increase the efficiency of photosynthesis, resulting in greater yields without loss of quality.

Results of this magnitude couldn't come at a more crucial time. The most recent UN report has found that in 2021 nearly 10 percent of the world population was hungry, a situation that has been steadily worsening over the last few years and eclipsing all other threats to global health in scale.

According to UNICEF, by 2030, more than 660 million people are expected to face food scarcity and malnutrition. Two of the major causes of this are inefficient food supply chains, or access to food, and harsher growing conditions for crops due to climate change.

Improving access to food and improving the sustainability of food crops in impoverished areas are the key goals of this study and the RIPE project.

The Illinois research shows an effective way to contribute to food security for the people who need it most while avoiding more land being put into production. Improving photosynthesis is a major opportunity to gain the needed jump in yield potential.

Leaves gain extra minutes of photosynthesis which, when added up throughout the entire growing season, increases the total photosynthetic rate. This research has shown that despite achieving a more than 20 percent increase in yield, seed quality was not impacted.

Despite higher yield, seed protein content was unchanged. This suggests some of the extra energy gained from improved photosynthesis was likely diverted to the nitrogen-fixing bacteria in the plant's nodules.

The researchers first tested their idea in tobacco plants because of the ease of transforming the crop's genetics and the amount of seeds that can be produced from a single plant.

The results show realising yield improvements is strongly affected by the environment. It is critical to determine the repeatability of this result across environments and further improvements to ensure the environmental stability of the gain.

Additional field tests of these transgenic soybean plants are being conducted this year, with results expected in early 2023.

The major impact of this work is to open the roads for showing that we can bioengineer photosynthesis and improve yields to increase food production in major crops.