Metabolomics analysis of Dendrobium officinale tissue-cultured seedlings under red-blue composed light by using HPLC and UPLC-Q/TOF-MS

Dendrobium officinale is a perennial herb with medicinal and edible qualities. The growth and nutritional properties of this plant are significantly affected by the light quality. However, the impact of varying light quality on the phytochemical characteristics of tissue-cultured seedlings of D. officinale is still unknown. In this study, tissue-cultured seedlings of D. officinale were grown for ninety days under six LED lights, including white light (W), blue LED (B), red LED (R), and three composite light environments with varying quantities of red and blue light: 1:2 (R1B2), 1:1 (R1B1), and 2:1 (R2B1). The growth status and physiological signs of the seedlings were analyzed and we used high-performance liquid chromatography (HPLC), ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC-Q/TOF-MS), and pathway enrichment analysis to thoroughly examine the metabolomic changes, with a focus on phenolic compounds. Our results indicated that R2B1 illumination led to the best growth of D. officinale seedlings, with maximal energy absorption, and phenolic contents. In conclusion, R2B1 was considered the most profitable for tissue-culture production of D. officinale.