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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 #424309
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: Genomic strategies to improve nitrogen use efficiency and reduce nitrate levels in sorghum forage lines

Author
item BRAYNEN, JANEEN - Cold Spring Harbor Laboratory
item KUMARI, SUNITA - Cold Spring Harbor Laboratory
item REGULSKI, MICHAEL - Cold Spring Harbor Laboratory
item ZHANG, LIFANG - Cold Spring Harbor Laboratory
item OLSON, ANDREW - Cold Spring Harbor Laboratory
item KUMAR, VIVEK - Cold Spring Harbor Laboratory
item ROONEY, WILLIAM - Texas A&M University
item Klein, Robert
item CORREA, EDGAR - Texas A&M University
item Ware, Doreen
item Boerman, Nicholas

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/11/2025
Publication Date: 3/11/2025
Citation: Braynen, J., Kumari, S., Regulski, M., Zhang, L., Olson, A., Kumar, V., Rooney, W.L., Klein, R.R., Correa, E., Ware, D., Boerman, N.A. 2025. Genomic strategies to improve nitrogen use efficiency and reduce nitrate levels in sorghum forage lines. Meeting Abstract. Network Biology Meeting.

Interpretive Summary:

Technical Abstract: Nitrogen (N) is a critical macronutrient that drives plant growth, development, and productivity. However, optimizing nitrogen use in crops presents both agricultural and environmental challenges. Building on our previous work investigating early molecular responses to nitrogen limitation and recovery in maize and sorghum, we employed gene regulatory networks to uncover key differences in how these closely related species respond to nitrogen stress. Our findings reveal distinct regulatory mechanisms, suggesting species-specific strategies for managing nitrogen fluctuations. Sorghum, in particular, is an essential forage crop in diverse agricultural systems. Effective nitrogen management is vital for improving both crop yield and forage quality, yet excessive use of nitrogen fertilizers can have detrimental environmental consequences. Nitrogen runoff from agricultural soils contributes to eutrophication in water bodies, while high nitrate accumulation in forage plants poses a risk of nitrate poisoning in ruminant animals. To address these challenges, we conducted transcriptomic analysis of hydroponically grown samples of four male-sterile sorghum A-lines (ATx645, ATx3408, A.11022, and A.07258bst) under high nitrate conditions (20 mM ammonium nitrate). Our results revealed significant variation in gene expression across these lines, particularly in genes associated with nitrate reduction, transport, and photosynthesis. These line-specific expression patterns correlated with known differences in nitrate accumulation, indicating that some genotypes may be more efficient in nitrogen assimilation and capable of reducing leaf nitrate buildup. By identifying genetic pathways that regulate nitrate accumulation, our findings provide valuable targets for breeding programs aimed at reducing nitrate levels in forage sorghum. Based on our previous studies on nitrogen toxicity in sorghum leaves, reducing leaf nitrate concentrations below the toxicity threshold of 10,000 µg g'¹ while maintaining productivity offers a sustainable solution for producing forage that is both safe for animal consumption and environmentally responsible. This study contributes to ongoing efforts to reduce reliance on nitrogen fertilizers, promote nutrient-use efficiency, and minimize the environmental impact of agricultural production.