A relatively recent technique termed comprehensive multiphase (CMP) NMR spectroscopy was used to investigate the growth and associated metabolomic changes of 13C-labeled wheat seeds and germinated seedlings. CMP-NMR enables the study of all phases in intact samples (i.e., liquid, gel-like, semisolid, and solid), by combining all required electronics into a single NMR probe, and can be used for investigating biological processes such as seed germination. All components, from the most liquid-like (i.e., dissolved metabolites) to the most rigid or solid-like (seed coat) were monitored in situ over 4 days. A wide range of metabolites were identified, and after 96 h of germination, the number of metabolites in the mobile phase more than doubled in comparison to 0 h (dry seed). This work represents the first application of CMP-NMR to follow biological processes in plants.
Keywords: 13C NMR; CMP; HSQC; NMR; Triticum aestivum; comprehensive multiphase; early seedling growth; germination; metabolites; seed; wheat.