b'SOYBEAN SUPERPOWERHow soybeans are teaching scientists a new way to breed for stress resilience.By Aimee Nielson, Seed World U.S. EditorHEAT WAVES AND droughts arent just climate buzzwordstheyre yield killers. But soybeans have a secret: they cool their flowers and pods like tiny natural air conditioners, leaving the rest of the plant to fend for itself. Now, scientists want to turn that survival tactic into a breeding strategy.When it comes to protecting yield in soybeans, researchers are look-ing past the leaves and into the plants reproductive core. At the University of Missouri, Ron Mittler and his team have uncovered a biological survival mechanism that reveals these legumes have a clever way of staying cool where it countsand that quirk of physiology might just be the seed industrys next big trait target.The process, called differential transpiration, allows soybean plants to conserve water by selectively cooling flowers and pods, the tissues responsible for reproduction, while closing off stomata in the leaves. This seemingly simple change in physiology could become a cornerstone trait for future soybeans bred to survive intensifying climate extremes.Plants can cool themselves only one way, and thats transpira-tion, Mittler explains. They open the stomatathe pores on their leaves, flowers and podsand lose water. That process cools the plant. But if they open all the stomata, they lose a lot of water. So instead, they close the stomata on the leaves and keep them open on the flowers and pods. That allows them to cool the tissues that matter most for yield.This strategy, Mittler says, reflects evolutionary pressure on annual crops like soybeans to protect reproduction at all costs.For annual plants, the priority is to invest everything they can in the production of seeds, he says. So if you need to cool the plantPlant biologist Ron Mittler investigates by transpiration, you prioritize cooling the reproductive tissues over thehow soybeans manage water and vegetative tissues. Its a whole different universe. temperature stress at the molecular level.Photo: University of MissouriA New Target for BreedingThe discovery opens new possibilities for both traditional breeding and genome editing.We can look at all these genotypes and see if they are prioritizing transpiration better, Mittler says. Can we breed that into our elite cul-tivars? Another option is to use genome editing for example, increasing stomatal density on reproductive tissues or keeping them open longer.24 SEEDWORLD.COM/CANADA JANUARY 2026'