Researchers have developed a groundbreaking new method called Chemical Exchange Saturation Transfer (CEST) that enables noninvasive magnetic resonance imaging (MRI) of plant metabolites, opening up new possibilities for understanding and improving crop plants.
A Test for the Dynamic Metabolome
Modern plant science and systems biology have been driven to a large extent by the ‘omics’ technologies – genomics, transcriptomics, proteomics, metabolomics etc. However, while the genome is relatively stationary, the products of the metabolome are highly dynamic and vary significantly both spatially wide or narrow and temporally fast or slow.
In biomedicine, nuclear magnetic resonance (NMR) imaging or magnetic resonance imaging (MRI) is a key technology for metabolic diagnostic and functional studies in vivo. Until now, a perspire-like perspective has been wanted but not yet investigated in plant science. A new CEST approach developed by researchers at the Julius-Maximilians-Universität Würzburg (JMU) and the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), focuses on recovering this niche, directly accessing intermediary carbohydrate metabolism in large sink organs of important crop species noninvasively.
Challenges of Plant MRI
Standard H NMR microscopy of biological tissue (e.g., plants) predominantly used signals arising from water or lipid protons. Nonetheless, in vivo the signal of metabolite protons is at least three orders of magnitude lower compared to water, which poses a challenging task in detecting metabolites.
The CEST approach, developed in the biomedical field, provides a way to address that. During CEST imaging, magnetization is transferred from other molecules to water protons, and by that different metabolites can be detected according their proton exchange with water. In combination with a flexible radio-frequency (RF) coil, the introduced second quadrature signal can serve as an extra proton MRI contrast that is high-sensitivity and less affected by magnetic field inhomogeneities and therefore, has potential for mapping solid state materials with strong lineshape overlaps that would be difficultly analyzed by conventional MRS.
Conclusion
The CEST method is a milestone in plant science and systems biology by the development of this technique for plant MRI. CCDS is a noninvasive imaging technique that affords exciting new ability to track metabolism but is needed for improved sampling of dynamic changes in plant metabolites that can be key drivers of trait formation and provide better support roles for breeding. The CEST strategy, which integrates structural and metabolic information in the context of rapidly adapting plant processes to environmental changes, offers tools for guiding future strategies directed towards enhancing crop productivity and sustainability.
