Interspecies Developmental Differences in Metabonomic Phenotypes of Lycium ruthenicum and L. barbarum Fruits

Fruits of Lycium ruthenicum (LR) and L. barbarum (LB) in Solanaceae family contain abundant bioactive metabolites used widely as functional food and natural medicine. To characterize the fruit developmental molecular phenotypes, we comprehensively analyzed metabolite composition of both Lycium fruits at three developmental stages using the combined NMR, liquid chromatography-tandem mass spectrometry, and gas chromatography-flame ionization detector/mass spectrometry methods. The metabonomes of these fruits were dominated by over 90 metabolites including sugars, amino acids, tricarboxylic acid (TCA) cycle intermediates, fatty acids, choline metabolites, and shikimate-mediated plant secondary metabolites. Metabolic phenotypes of two species differed significantly at all three developmental stages; LB fruits contained significantly more sugars and amino acids but less TCA cycle intermediates, fatty acids, and secondary metabolites than LR. Interspecies differences for fatty acid levels were much greater after color-breaking than precolor-breaking. Furthermore, LR fruits contained more osmolytes than LB fruits indicating different osmoregulation requirements for these fruits during development. Significant differences were also present in biosynthesis of shikimate-mediated plant secondary metabolites in LR and LB. These findings provided essential metabolic information for plant physiology of these  Lycium species and their utilizations demonstrating the usefulness of this metabonomic phenotyping approach for studying fundamental biochemistry of the plant development.