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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 #436600
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: Natural genetic variation reveals mechanisms of iron stress adaptation and environmental resilience in Sorghum

Author
item DOOLING, KATE - Cold Spring Harbor Laboratory
item BRAYNEN, JANEEN - Cold Spring Harbor Laboratory
item KUMARI, SUNITA - Cold Spring Harbor Laboratory
item REGULSKI, MICHAEL - Cold Spring Harbor Laboratory
item CHOUGULE, KAPEEL - Cold Spring Harbor Laboratory
item OLSON, ANDREW - Cold Spring Harbor Laboratory
item OLSON, CHRISTOPHER - Cold Spring Harbor Laboratory
item KIM, MATTHEW - Cold Spring Harbor Laboratory
item COOPER, ELIZABETH - North Carolina State University
item Ware, Doreen

Submitted to: American Society of Plant Biologists Annual Meeting
Publication Type: Book / Chapter
Publication Acceptance Date: 7/18/2026
Publication Date: 7/18/2026
Citation: Dooling, K., Braynen, J., Kumari, S., Regulski, M., Chougule, K., Olson, A., Olson, C., Kim, M., Cooper, E., Ware, D. 2026. Natural genetic variation reveals mechanisms of iron stress adaptation and environmental resilience in Sorghum . American Society of Plant Biologists Annual Meeting. The American Society of Plant Biologists (ASPB) Plant Biology 2026 Conference.

Interpretive Summary:

Technical Abstract: As the global population grows and arable land declines, improving nutrient use efficiency and stress resilience in crops is essential for sustainable agriculture. Iron (Fe) deficiency is a major constraint on crop productivity, particularly in alkaline soils where Fe availability is limited. Rising temperatures further reduce photosynthetic performance and yield, making it critical to understand mechanisms that enable plants to adapt to multiple environmental stresses. To investigate genetic variation in stress responses, we conducted two hydroponic experiments in sorghum. In the first, four Carbon Partitioning Nested Association Mapping (CP-NAM) founder lines (Grassl, Leoti, Pink Kafir, and IS13633) and the reference genotype BTx623 were evaluated under Fe-limited and Fe-excess conditions. In the second, Leoti and BTx623 were exposed to combined Fe limitation and heat stress at 30°C, 35°C, and 40°C. Plants in the first experiment were sampled at 0, 7, and 14 days. Physiological and transcriptomic analyses revealed strong genotype- and time-dependent differences in Fe accumulation, growth, and stress responses. Although all genotypes developed chlorosis under Fe limitation, Leoti showed delayed symptom development and maintained higher leaf Fe concentrations, indicating enhanced Fe-use efficiency. Transcriptomic analyses identified dynamic regulation of sulfur metabolism, Fe-S cluster assembly, electron transport, and metal transport pathways. BTx623 and Leoti maintained relatively stable expression of these pathways, with early responses sustaining electron transport and later responses involving broader metabolic adjustments, particularly in Leoti. Under combined Fe limitation and heat stress, Leoti demonstrated greater physiological stability than BTx623. Time-series chlorophyll measurements taken over 7 days showed sustained photosynthetic capacity during early stress exposure, especially at 40°C. Collectively, these findings suggest that Leoti possesses regulatory mechanisms that enhance adaptation to both Fe deficiency and heat stress, highlighting the potential of natural genetic variation in sorghum for developing climate-resilient and nutrient-efficient cultivars.