b'SwitchgrasS chemistryShiftA new look at drought-stressed switchgrass reveals why breeding and biofuel science must work together to fuel the future.By Aimee Nielson, Seed World U.S. EditorIN THE WAKE OFincreasingly unpredictable weather patterns, researchers are zeroing in on an underap-preciated hurdle in the biofuel pipelinethe chemistry of drought-stressed plants.At the University of Wisconsin-Madisons Great Lakes Bioenergy Research Center (GLBRC), senior scientist Trey Sato leads efforts to understand why switchgrass grown in dry conditions produces less ethanol. The culprit? A natural compound called saponin.In collaboration with others, we found that high con-centrations of plant molecules called saponins inhibit the fermentation of switchgrass hydrolysates to biofuels by our yeast strain, Sato says.Saponins are part of the plants innate defense system,Switchgrass research plots at the Great Lakes offering protection against fungal pathogens like rust. ButBioenergy Research Center, where scientists their increase during drought becomes a problem for down- study how stress conditions affect fuel yields.stream fermentationthe critical step where sugars arePHOTO: TREY SATOconverted into usable fuel.44/ SEEDWORLD.COMOCTOBER 2025'