Session: Session 5
Combination of Mass Spectrometry and Nuclear Magnetic Resonance for annotation and quantification of metabolites in root exudates
Root exudates are compounds released by plants into the soil1. They are one of the main sources of carbon available to soil microorganisms, and are involved in a wide range of interactions at the plant-soil interface (root defense against pathogens, environmental stresses...)1,2.
Due to their importance in establishing the rhizosphere and regulating its properties, it is necessary to characterize the precise composition and function of exudates at the root-soil interface. Preliminary studies conducted in our laboratory have separately used nuclear magnetic resonance (NMR) and mass spectrometry (MS) coupled to liquid chromatography (LC) to identify part of these metabolites3,4. However, difficulties were encountered in MS feature assignments due to isomer issues or low-ionization efficiencies, and in annotations by NMR explained by the absence or the very low amount of some compounds. In this context, cross-comparison of MS and NMR data sets could ensure or at least facilitate compound annotation and increase annotation levels.
Here, we elaborated a common protocol for both analytical techniques for sampling root exudates. Our preliminary results are promising to establish a database common to MS and NMR, essential for a more confident identification and characterization of these metabolites.
1. Ma, W. et al. Root exudates contribute to belowground ecosystem hotspots: A review. Frontiers in Microbiology vol. 13 Preprint at https://doi.org/10.3389/fmicb.2022.937940 (2022).
2. Badri, D. V., and Vivanco, J. M. Regulation and function of root exudates. Plant Cell Environ 32, 666–681 (2009).
3. Fortier, M. et al. Development of a root exudate collection protocol for metabolomics analysis using Nuclear Magnetic Resonance. Plant Sci 331, (2023).
4. Calabrese, V. et al. Direct introduction MALDI FTICR MS based on dried droplet deposition applied to non-targeted metabolomics on Pisum Sativum root exudates. Talanta 253, 123901 (2023).
Due to their importance in establishing the rhizosphere and regulating its properties, it is necessary to characterize the precise composition and function of exudates at the root-soil interface. Preliminary studies conducted in our laboratory have separately used nuclear magnetic resonance (NMR) and mass spectrometry (MS) coupled to liquid chromatography (LC) to identify part of these metabolites3,4. However, difficulties were encountered in MS feature assignments due to isomer issues or low-ionization efficiencies, and in annotations by NMR explained by the absence or the very low amount of some compounds. In this context, cross-comparison of MS and NMR data sets could ensure or at least facilitate compound annotation and increase annotation levels.
Here, we elaborated a common protocol for both analytical techniques for sampling root exudates. Our preliminary results are promising to establish a database common to MS and NMR, essential for a more confident identification and characterization of these metabolites.
1. Ma, W. et al. Root exudates contribute to belowground ecosystem hotspots: A review. Frontiers in Microbiology vol. 13 Preprint at https://doi.org/10.3389/fmicb.2022.937940 (2022).
2. Badri, D. V., and Vivanco, J. M. Regulation and function of root exudates. Plant Cell Environ 32, 666–681 (2009).
3. Fortier, M. et al. Development of a root exudate collection protocol for metabolomics analysis using Nuclear Magnetic Resonance. Plant Sci 331, (2023).
4. Calabrese, V. et al. Direct introduction MALDI FTICR MS based on dried droplet deposition applied to non-targeted metabolomics on Pisum Sativum root exudates. Talanta 253, 123901 (2023).