Plants have the extraordinary ability to convert sunlight into food through photosynthesis. However, just because something is natural doesn’t mean it’s efficient. Most crops on the planet have to deal with a process called photorespiration that significantly reduces their yield. Now scientists have engineered a way for plants to go around it.
As reported in Science, scientists have developed several alternative ways for plants to perform photorespiration so that it's not as energy consuming. Combinations of new genes and promoters were tested in 1,700 plants in real-world conditions and the top performers were isolated.
The research is part of the Realizing Increased Photosynthetic Efficiency (RIPE) study, an international project to increase the photosynthesizing ability of crops to improve worldwide food productivity. This work took over two years of replicating the results, but the team showed that the engineered plants ended up being taller and developing faster. Around 40 percent more biomass was produced, most of which was found in the crops' stems, which were 50 percent larger.
“We could feed up to 200 million additional people with the calories lost to photorespiration in the Midwestern U.S. each year,” principal investigator Donald Ort, Robert Emerson Professor of Plant Science and Crop Sciences, said in a statement. “Reclaiming even a portion of these calories across the world would go a long way to meeting the 21st Century’s rapidly expanding food demands – driven by population growth and more affluent high-calorie diets.”
Photorespiration is not an intrinsically bad process but an unfortunate necessity for plants. The enzyme Rubisco, crucial to photosynthesis, is capable of creating compounds toxic to plants. This means it has to be recycled via photorespiration, which is energy consuming.
“Photorespiration is anti-photosynthesis,” added lead author Paul South, a research molecular biologist with the Agricultural Research Service. “It costs the plant precious energy and resources that it could have invested in photosynthesis to produce more growth and yield.”
The team estimated that it would take roughly a decade to engineer this hack into staple food crops and achieve regulatory approval. The project and their founders also intend to ensure that smallholder farmers, especially in Sub-Saharan Africa and Southeast Asia, can access all the breakthrough from the project free of royalties.