Engineered potatoes show 30% growth boost under heatwaves
A team from the University of Illinois has engineered potatoes to be more resilient to global warming, demonstrating a 30% increase in tuber mass under heatwave conditions. This suggests that improving photosynthesis could help create climate-resilient crops, offering a promising solution to the challenges posed by global warming.
The ability to enhance potato resilience may provide greater food security for families who depend on this staple crop, especially in regions already experiencing the impacts of climate change. These areas often face multiple crop failures due to increasingly erratic weather patterns.
Katherine Meacham-Hensold, scientific project manager for the Realizing Increased Photosynthetic Efficiency (RIPE) project, explains, “We need to develop crops that can withstand more frequent and intense heatwaves if we are to meet the growing food demand in regions most at risk from reduced yields due to climate change.”
The potato plants with an engineered photorespiratory bypass were started in a greenhouse before being transplanted into the field, where they were subjected to high temperatures.Meacham-Hensold led this work for RIPE, an international research initiative focused on improving food security by developing food crops that turn the sun’s energy into food more efficiently. RIPE is supported by Bill & Melinda Gates Agricultural Innovations (Gates Ag One).
Greater growth
The team engineered potatoes with a photorespiratory bypass. The plants were started in a greenhouse before being transplanted into the field, where they were exposed to extreme heat. Photorespiration is a process in which the enzyme rubisco reacts with oxygen instead of carbon dioxide, a phenomenon that increases significantly in high temperatures and reduces crop yields by up to 40% in crops like soybean, rice, and vegetables.
When photorespiration occurs, plants expend significant energy to process the resulting toxic byproduct, glycolate, rather than using that energy for growth. Photorespiration is a major energy drain on plants, Meacham-Hensold notes. ““It takes away from food production as energy is diverted to metabolizing the toxin. Our goal was to reduce the amount of wasted energy by bypassing the plant’s original photorespiratory pathway.”
Previously, RIPE researchers added 2 genes – glycolate dehydrogenase and malate synthase – to model plants, which improved photosynthetic efficiency by metabolising glycolate in the chloroplasts, the cell compartments responsible for photosynthesis. This modification reduced the energy required to process glycolate, resulting in greater growth. The team hoped this success would carry over into food crops, and their results exceeded expectations.
Nutritional quality
Published in Global Change Biology, the study found that the genetically engineered potatoes demonstrated a remarkable 30% increase in tuber mass compared to control potatoes, particularly under heatwave conditions. The modified potatoes thrived in temperatures exceeding 95°F (35°C), even reaching 100°F (38°C) during a 4-day heatwave in the summer of 2022. Afterward, the modified plants continued to grow robustly, while the control potatoes showed signs of heat stress and limited growth.
“Another key finding of this study was the demonstration that our genetic engineering of photosynthesis that produced these yield increases had no impact on the nutritional quality of the potato”, says Don Ort, Robert Emerson Professor of Plant Biology and Crop Sciences and Deputy Director of the RIPE project. “Food security is not just about the amount of calories that can be produced but we must also consider the quality of the food.”
While additional multi-location field trials are necessary to confirm these results in diverse environments, the success with potatoes raises hopes that similar improvements could be made in other root tuber crops, such as cassava, which is a vital food source in Sub-Saharan Africa. This region, already vulnerable to the effects of climate change, could greatly benefit from crops that are more resilient to rising global temperatures.
