Light and Potassium Improve the Quality of Dendrobium officinale through Optimizing Transcriptomic and Metabolomic Alteration

Abstract

Background: Dendrobium officinale is a perennial epiphytic herb in Orchidaceae. Cultivated products are the main alternative for clinical application due to the shortage of wild resources. However, the phenotype and quality of D. officinale have changed post-artificial cultivation, and environmental cues such as light, temperature, water, and nutrition supply are the major influencing factors. This study aims to unveil the mechanisms beneath the cultivation-induced variation by analyzing the changes of the metabolome and transcriptome of D. officinale seedlings treated with red- blue LED light and potassium fertilizer. Results: After light- and K-treatment, the D. officinale pseudobulbs turned purple and the anthocyanin content increased significantly. Through wide-target metabolome analysis, compared with pseudobulbs in the control group (P), the proportion of flavonoids in differentially-accumulated metabolites (DAMs) was 22.4% and 33.5% post light- and K-treatment, respectively. The gene modules coupled to flavonoids were obtained through the coexpression analysis of the light- and K-treated D. officinale transcriptome by WGCNA. The KEGG enrichment results of the key modules showed that the DEGs of the D. officinale pseudobulb were enriched in phenylpropane biosynthesis, flavonoid biosynthesis, and jasmonic acid (JA) synthesis post-light- and K-treatment. In addition, anthocyanin accumulation was the main contribution to the purple color of pseudobulbs, and the plant hormone JA induced the accumulation of anthocyanins in D. officinale. Conclusions: These results suggested that light and potassium affected the accumulation of active compounds in D. officinale, and the gene-flavone network analysis emphasizes the key functional genes and regulatory factors for quality improvement in the cultivation of this medicinal plant.

Changes in Quercetin Derivatives and Antioxidant Activity in Marigold Petals (Tagetes patula L.) Induced by Ultraviolet-B Irradiation and Methyl Jasmonate

“…Previous research has reported on the increase in flavonoid content and associated gene expression by UV-B and MeJA treatments [ 23 , 24 , 25 ]. These compounds are produced as antioxidants for the removal of free radicals caused by abiotic stress.…”

HPLC-based metabolomics of Dendrobium officinale revealing its antioxidant ability

“…It has been observed that the production of polysaccharides D. officinale decreases gradually, with the increase in altitude and decrease in temperature ( He et al., 2022 ). Light-treatment affected the accumulation of primary and secondary metabolites in D. officinale , especially the biosynthesis of flavonoids, which the components of flavonoid glycosides were significantly upregulated ( Jia et al., 2022 ). Zuo et al.…”

“…It has been observed that the production of polysaccharides D. officinale decreases gradually, with the increase in altitude and decrease in temperature (He et al, 2022). Light-treatment affected the accumulation of primary and secondary metabolites in D. officinale, especially the biosynthesis of flavonoids, which the components of flavonoid glycosides were significantly upregulated (Jia et al, 2022). Zuo et al, (2020) conducted a comparative analysis of the metabolomics of D. officinale under different cultivation substrates, and they found that only three shared metabolites differed significantly among the different comparisons.…”