Metabolite profiling approach for assessing the effects of colored light-emitting diode lighting on the adventitious roots of ginseng (Panax ginseng

Metabolome analysis was carried out to evaluate the effects of light-emitting diode (LED) spectra on the metabolic processes of ginseng (Panax ginseng C. A. Mayer) adventitious roots. In total, 35 hydrophilic and 11 lipophilic metabolites were identified in ginseng roots irradiated with red (630 nm), blue (465 nm) LED light or fluorescent lamp (FL) light, by gas chromatography–time-offlight mass spectrometry. Principal components analysis results using the 46 metabolites showed differentiation between the metabolomes of ginseng roots irradiated with red LED, blue LED, and FL light, indicating that metabolic changes were occurred in the ginseng roots by light spectral quality. The corresponding loading indicated that LED light-irradiated ginseng roots had higher sucrose and lower amino acids compared to FL-irradiated ginseng roots. The quantitative results revealed that ginseng roots irradiated with blue LED light had higher concentrations of α-tocopherol and β-amyrin, as well as phenolic acids compared with FLirradiated ginseng roots. This is the first study to determine the comprehensive metabolic changes in response to LED light in ginseng adventitious roots and to demonstrate the utility of the metabolite profiling approach employed in this study for detecting environmental effects on the plant metabolome.