Earlier this year, a team of researchers from across the US and UK claimed to have substantially boosted yields on tobacco plants grown in a lab by improving the natural process of photosynthesis. That same team, led by Stephen Long, a professor of plant biology based at both the University of Illinois and the University of Lancaster, has repeated those results in field trials utilizing soybean plants. The genetically altered crop achieved more than a +20% yield boost thanks to a more efficient method of harnessing the Sun’s energy.
Photosynthesis is critical for plant growth. The multistage process, which involves some 150 unique steps, converts sunlight into carbon dioxide and water into sugars that fuel a plant’s growth. But one critical stage of this natural process costs up to 40% of a plants full potential productivity. The problem lies with a plant’s slow response time to light changes.
In very bright sunlight, plants switch into a protective mode and release excess energy as heat, to avoid damage to their cells, a mechanism known as “photoprotection.” Plants in bright sunlight are exposed to more light energy than they can use, so shed the excess as heat. However, it can take several minutes for a plant to switch out of “protective mode” and back into “fully productive growth mode.” The genetically engineered crops, by contrast, were tweaked to switch back into productive mode more swiftly, thus gaining more photosynthesis time and increasing yields.
The gene altered soybeans were grown during two separate crop seasons in Urbana, Illinois. In five of the eight GM varieties planted in 2020, yields averaged +24.5% higher than the non-GM control soybeans. Long said the other three GM soybeans also yielded higher but not by a statistically significant amount. According to Long, results from the 2021 crop, were less conclusive due to a storm that caused the plants’ leaves to collapse on top of one another, which permanently shaded the lower leaves. Still, seed yield increased in some cases up to +33%. Additional field tests are being conducted this year, with results expected in early 2023.
“This jump in the yield is huge by comparison to the improvements we get through plant breeding,” said Long. “And the process we’ve tackled is universal, so the fact we have it working in a food crop gives us a lot of confidence that this should work in wheat, maize and rice.” While Long ideally hopes to complete five years of field trials, he believes similarly genetically modified crops could be growing in fields within the decade.
Long’s research is part of Realizing Increased Photosynthetic Efficiency, or RIPE, an international research project that aims to increase global food production by improving photosynthetic efficiency in food crops for smallholder farmers in Sub-Saharan Africa with support from the Bill & Melinda Gates Foundation, Foundation for Food & Agriculture Research, and U.K. Foreign, Commonwealth & Development Office. You can learn more about the research HERE.
