b'Unlocking the Secrets to Shorter Grain CornISU researchers identify genetic traits that control Auxin and developshorter corn plants.By Peter Scharpe, Seed World ContributorIN THE RAPIDLY EVOLVINGfield of seed science, break-throughs that can change the future of farming are always around the corner. Dior Kelley, assistant professor at Iowa State University Department of Genetics, Development and Cell Biology, recently made a discovery that could fundamentally alter how corn is grown. Kelley and her team identified a genetic pathway that they can manipulate to selectively control the height of corn through the plant hormone auxin. Interestingly, the journey that ledKelley to this breakthrough started with a different goal in mindcontrolling root growth.My research team focuses on identifying genetic drivers of root growth and development, Kelley explained. They do a lot of heavy lifting and so we really wanted to figure out how root systems are controlled.Focus on Auxin and Root GrowthWhile there are several growth hormones and genetic driv-ers that can impact a plants growth, Kelleys team focused on auxin, a well-known growth hormone in plants. Auxin is respon-sible for a wide range of developmental processes, including cell elongation, root growth and fruit development. The research started by conducting genetic screens to identify specific auxin pathway genes. Specifically, the pathways that impact root growth. They identified a gene sequence that encodes for an auxin transporter which would move the hor-mone across the cells. It turns out that when we dial down the expression of this transporter in corn, it leads to many changes in organ size, not just the roots, but also in the shoots, she said. The researchers conducted field trials where they could easily spot plants with the desired genetic traits, as these plants were visibly shorter than their counterpartsapproximately 25% shorter, translating to a height reduction of one to two feet.This unexpected finding shifted the teams focus, opening new doors to controlling the overall architecture of corn plants, especially in reducing their height.18/ SEEDWORLD.COMJANUARY 2025'