Genomic Science Program
U.S. Department of Energy | Office of Science | Biological and Environmental Research Program

2024 Abstracts

Quantum-Entangled Hyperpolarized Spin States for Noninvasive Imaging of Nitrogen Assimilation

Authors:

Thomas Theis* ([email protected], PI)

Institutions:

North Carolina State University

URLs:

Abstract

Nitrogen (N) fertilizer synthesis for agriculture sustains about half of the human population. Recent studies show that N input from N-fertilizer synthesis and river runoff poses a serious and growing problem with intensifying climate change. To address these major societal challenges, improvements to today’s agricultural strategies are necessary; however, the scientific community’s knowledge of plant–soil–microbe interactions in unperturbed soil remains extremely limited because of lacking noninvasive technology to probe metabolism. Here, this team develops new, noninvasive quantum sensing to directly observe metabolic transformation in the rhizosphere to acquire currently inaccessible knowledge.

This group’s approach takes advantage of the quantum- entangled nuclear spin state in hydrogen gas (i.e., parahydrogen), which can readily be enriched to ~99.5% to enhance magnetic resonance imaging (MRI) signals by up to seven orders of magnitude, such that metabolites at low, physiological concentrations become detectable by MRI even at low magnetic fields. The figure (see p. 14; A) shows the target metabolites central to N assimilation and their metabolic pathways; (B) illustrates hyperpolarization chemistry, which transfers the nuclear spin hyperpolarization to the metabolites of interest; (C) shows images of the hyperpolarized metabolite at low concentrations and low field in a test tube; (D) shows an example of noninvasive low-field MRI; and (E) illustrates the goal of obtaining molecular imaging of metabolic transformations in the rhizosphere with portable devices that could be employed directly in the field.

This poster shows significant progress towards several goals:

  • The team has significantly expanded the substrate scope of its parahydrogen-based hyperpolarization technique.
  • The team has detailed the fundamental quantum chemistry and spin dynamics governing the polarization transfer processes.
  • The team has demonstrated MRI of the hyperpolarized molecular sensors at low magnetic fields and low concentrations.
  • The team has enabled the detection of long-lived carbon-13 hyperpolarized metabolites on existing low-field hydrogen MRI systems that are already deployed in crop fields.

The team has demonstrated the very first detection of metabolic conversions with this technique using cryogen-free MRI systems. In summary, exciting progress toward noninvasive imaging of nitrogen assimilation using quantum-entangled hyperpolarized spin states will be presented.

Image

As described in caption.

Using Quantum-Entangled Nuclear Spin States for Noninvasive Magnetic Resonance Imaging of Nitrogen Assimilation in the Rhizosphere. (A) Metabolic conversions of relevance in nitrogen assimilation. (B) Hyperpolarization chemistry: the entangled nuclear spin state of hydrogen is used to induce spin alignment on a metabolite (pyruvate) mediated by a polarization transfer catalyst. (C) Recent results demonstrating pyruvate imaging at a low mm concentration with sub-mm resolution in the Theis Lab. (D) Low-field root magnetic resonance imaging (MRI) images in soil by Rosen Lab. (E) Simulated chemical shift images that report on metabolism and molecular turnover from glutamate to glutamine. [(A) Adapted and reused under a Creative Commons license (CC by 4.0) from Lu, J., et. al. 2016. “Expression of a Constitutively Active Nitrate Reductase Variant in Tobacco Reduces Tobacco-Specific Nitrosamine Accumulation in Cured Leaves and Cigarette Smoke,” Plant Biotechnology Journal 14, 1500–10. (B) Courtesy North Carolina State University. (C) Adapted with permission from TomHon, P., et al. 2022. “Temperature Cycling Enables Efficient 13C SABRE-SHEATH Hyperpolarization and Imaging of [1-13C]- Pyruvate,” Journal of the American Chemical Society 144 (1), 282–87. DOI:10.1021/jacs.1c09581. (D, E) Bagnall, C., et al. 2020. “Low-Field Magnetic Resonance Imaging of Roots in Intact Clayey and Silty Soils,” Geoderma 370, 114356. DOI:10.1016/j. geoderma.2020.114356. Reused under a Creative Commons license (CC BY-NC-ND 4.0)]