b'Built-In Chill FactorHow soybeans are teaching scientists a new way to breed for stress resilience.By Aimee Nielson, Seed World U.S. EditorHEAT WAVES ANDdroughtsThat process cools the plant. But if arent just climate buzzwordsthey open all the stomata, they lose atheyre yield killers. But soybeanslot of water. So instead, they close the have a secret: they cool their flowersstomata on the leaves and pods like tiny natural air condi- and keep them open on tioners, leaving the rest of the plant tothe flowers and pods. fend for itself. Now, scientists want toThat allows them to turn that survival tactic into a breed- cool the tissues that ing strategy. matter most for yield.When it comes to protecting yieldThis strategy, Mittler in soybeans, researchers are lookingsays, reflects evolution-past the leaves and into the plantsary pressure on annual reproductive core. At the Universitycrops like soybeans to of Missouri, Ron Mittler and his teamprotect reproduction at have uncovered a biological survivalall costs.mechanism that reveals these leg-For annual plants, umes have a clever way of stayingthe priority is to invest cool where it countsand that quirkeverything they can of physiology might just be the seedin the production of industrys next big trait target. seeds, he says. So if The process, called differentialyou need to cool the transpiration, allows soybean plantsplant by transpiration, to conserve water by selectivelyyou prioritize cooling cooling flowers and pods, the tissuesthe reproductive tis-responsible for reproduction, whilesues over the vegetative tissues. Its aPlant biologist Ron Mittler closing off stomata in the leaves. Thiswhole different universe. investigates how soybeans seemingly simple change in physiol- manage water and temperature ogy could become a cornerstone traitA New Target for Breeding stress at the molecular level. for future soybeans bred to surviveThe discovery opens new possibili- PHOTO: UNIVERSITY OF MISSOURIintensifying climate extremes. ties for both traditional breeding and Plants can cool themselves onlygenome editing.one way, and thats transpiration,We can look at all these geno-Mittler explains. They open thetypes and see if they are prioritizing stomatathe pores on their leaves,transpiration better, Mittler says. Can flowers and podsand lose water.we breed that into our elite cultivars? 50/ SEEDWORLD.COMDECEMBER 2025'