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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Plant, Soil and Nutrition Research » Research » Publications at this Location » Publication #434151
Research Project: Championing Improvement of Sorghum and Other Agriculturally Important Species through Data Stewardship and Functional Dissection of Complex Traits

Location: Plant, Soil and Nutrition Research

Title: Integrating Transcriptomics and Ionomics to Dissect Iron Use Efficiency and Heat Stress Responses in Sorghum

Author
item BRAYNEN, JANEEN - Cold Spring Harbor Laboratory
item DOOLING, KATE - Cold Spring Harbor Laboratory
item KUMARI, SUNITA - Cold Spring Harbor Laboratory
item KUMAR, VIVEK - Cold Spring Harbor Laboratory
item CHOUGULE, KAPEEL - Cold Spring Harbor Laboratory
item REGULSKI, MICHAEL - Cold Spring Harbor Laboratory
item OLSON, CHRISTOPHER - Cold Spring Harbor Laboratory
item COOPER, ELIZABETH - University Of North Carolina
item Ware, Doreen

Submitted to: American Society of Plant Biologists
Publication Type: Abstract Only
Publication Acceptance Date: 4/25/2026
Publication Date: 4/25/2026
Citation: Braynen, J., Dooling, K., Kumari, S., Kumar, V., Chougule, K., Regulski, M., Olson, C., Cooper, E., Ware, D. 2026. Integrating Transcriptomics and Ionomics to Dissect Iron Use Efficiency and Heat Stress Responses in Sorghum. American Society of Plant Biologists. American Society of Plant Biologists Northeast Meeting.

Interpretive Summary:

Technical Abstract: Iron (Fe) is an essential micronutrient that limits sorghum productivity in marginal and calcareous soils, yet genetic variation for micronutrient use efficiency remains underutilized in breeding programs. While breeding efforts have emphasized yield and macronutrient inputs, understanding how diverse sorghum genotypes respond to Fe stress is critical for sustainable crop production. In parallel, rising global temperatures impose additional constraints by disrupting metabolism and nutrient imbalances, highlighting potential cross talk between heat and nutrient stress responses. To address these challenges, we examined four CP-NAM founder lines (Grassl, Leoti, Pink Kafir, and IS13633) and reference genotype BTx623 under Fe-limited and Fe-excess hydroponic conditions for 14 days in a greenhouse (28°C). Integrated transcriptomic and ionomic analyses revealed strong genotype- and time-dependent variation in Fe accumulation and growth. Under Fe limitation, most genotypes exhibited chlorosis, whereas Leoti maintained green pigmentation indicating enhanced Fe-use efficiency. ICP-MS analysis further revealed significant variability in micronutrient levels, including Fe54, Ca44, S³4, Na²³, and B¹¹, with Leoti showing relatively elevated Fe after prolonged stress under Fe limitation. Transcriptomic analyses identified dynamic regulation of Fe-responsive genes across both reduction-based (Strategy I) and chelation-based (Strategy II) pathways. We further assessed heat stress responses (40°C) in BTx623 and Leoti. Leoti exhibited greater physiological stability and distinct transcriptional responses under elevated temperature. Time-series chlorophyll measurements (atLEAF) showed a marked increase in chlorophyll in Leoti after 2–3 days of heat exposure under Fe limitation. Collectively, these findings demonstrate natural variation in sorghum responses to Fe and heat stress and identify candidate genotypes and regulatory mechanisms underlying multi-stress resilience.