Combined phenolomic approaches reveal elevated CO2 influences phenolic biosynthesis in wolfberry (Lycium barbarum)

The importance of studying the effects of CO2 concentration on metabolism increases as atmospheric CO2 concentrations rise globally. However, the reasons behind CO2 concentrations affect carbohydrate and phenolic metabolism remain unknown. Herein, we employed the novel phenolomic approach to gain insights into the quantitative and spatial variations of phenols that occur in wolfberry (Lycium barbarum) in response to elevated CO2. Data, combined from mass spectrometry imaging, gas chromatography coupled with mass spectrometry, and ultra-performance liquid chromatography coupled with tandem mass spectrometry utilizing electrospray ionization, provided a comprehensive overview of phenolomic quantities and spatial distribution. These data indicate that phenolics and precursors accumulate, and gene expression changes under elevated CO2; and these changes could act as strategies to cope with the stress associated with elevated CO2. Pathway analysis showed an increase of succinic acid, 3-methylglutaric acid, linoleic acid, nonadecanoic acid, chlorogenic acid, and rutin, a decrease of glucose, fructose, maltose, sucrose, and changes in the expression level of key genes involved in glyoxylate, phenylpropanoid, and flavonoid metabolism. From mass spectrometry imaging (MSI) data, the spatial distribution of different metabolites including malic acid, citric acid, coumarin, and naringenin localized near the periphery of the berry. Taken together, the present study not only demonstrate the potential for spatially resolved phenolomics to reveal an interactive network, but also have major implications for understanding of the phenolomic response to elevated CO2 atmosphere.