Mapping Carbon Allocation in Above and Belowground Organs and Root Exudates of NAM Founders and Slac1 Populations

Maize root system traits including growth rate, morphology and carbon allocation are poorly described. Yet, root traits can provide insight into plant responses to environmental stressors including reduced soil moisture. Root exudates, carbon released by roots into the soil, can help mitigate environmental stress factors through chemical, physical, and biological mechanisms including improving soil water retention, supporting beneficial microbes, enhancing nutrient access. A significant amount of carbon is released via this process. Root exudation is also influenced by multiple plant based variables, including genotype and developmental stages. Of 25 NAM founders and Slac1 genotypes, six, HP301, Mo18W, Slac1W22, B73, wtW22, & CML277, were selected via cluster analysis performed using morphological traits under well-water conditions, as well as seed germination for exudate analysis. Genotypic specific root exudates, dry, mass and surface area responded differently to drought. Root dry mass, surface area, and exudation rates reflected how selected genotypes allocate carbon throughout developmental stages under water stress. Exudation is a drought-response mechanism that is highest at VE and lowest in stages V3-4; overall exudation decreased logarithmically across all genotypes. The surface area tended to increase with growth stages, and the negative effects of drought became more pronounced over development. These findings further emphasize the role of roots in the response to water deficit and carbon allocation.

My experience as a BTI/CROPPS undergraduate researcher was deeply rewarding and transformative. During the 10-week program, I learned valuable professional skills and laboratory techniques. I spent the summer conducting hands-on experiments daily. The Baurle lab was a collaborative and uplifting environment. My mentor, Andrea Sanchez, was truly impactful. She led by example and broke down complex topics to further my understanding of our research and its impact. Overall, the experience made me a more confident science communicator, solidified my appreciation for plant biology, and reaffirmed my career goals.