Engineering crops to be more efficient

Abstract

From an engineering point of view, photosynthesis is inefficient. One out of every five tries, the enzyme that plants use to catch carbon dioxide mistakenly grabs on to oxygen, producing toxic glycolate instead of carbohydrate building blocks. This misstep is called photorespiration. Plants use a tremendous amount of precious energy to correct it. In fact, photorespiration reduces crop yields by an estimated 20–50%. Now researchers have demonstrated a better way to correct this photosynthetic error. Tobacco plants that were genetically engineered to more efficiently break down glycolate showed 40% greater crop yields in field trials (Science 2019, DOI: 10.1126/science.aat9077). If the findings can be replicated in food crops, farmers could produce more calories using less land and fertilizer. “This is a demonstration that you can alter photorespiration in a fundamental way and get significant gains in yields—and that’s exciting,” says Berkley Walker, a plant biologist at Michigan State University who