Objective To find out the optimal light quality for plant growth and bioactive metabolites accumulation of Angelica sinensis, and provide references for regulating the growth and metabolites product accumulation of A. sinensis. Methods The A. sinensis plants grown in pots were exposed to three different light qualities (red, blue, and infrared light) with white light as the control (CK), the growth characteristics of plants, contents of main bioactive metabolites, and expression level of key genes were determined. Results There were significant differences in the growth characteristics, main bioactive metabolites accumulation, and key genes expression of A. sinensis under different light qualities. Compared with the CK, blue light significantly promoted plant height, root length, chlorophyll content, and stomatal aperture; red light and infrared light could promote some growth parameters (e.g., plant height and aerial parts dry weight) to some extent; however, the blue, red, or infrared light had no significant effect on biomass accumulation. Red light significantly promoted soluble sugar accumulation, blue light significantly promoted total flavonoids accumulation, while infrared light significantly promoted accumulation of ferulic acid, ligustilide and total phenolics as well as in vitro antioxidant capacity. The three light qualities could promote the expression levels of almost genes related to the biosynthesis of main bioactive metabolites (i.e., ferulic acid, flavonoids, volatile oils, and polysaccharides); for example, the caffeic acid 3-O-methyltransferase (COMT) gene involved in ferulic acid biosynthesis showed the highest upregulation under blue light, the chalcone isomerase 2 (CHI2) gene involved in flavonoid biosynthesis was significantly upregulated under infrared light; and the 1-deoxy-D-xylulose 5-phosphate synthase (DXS) gene involved in volatile oil biosynthesis was significantly upregulated under red light. Conclusion Monochromatic light qualities (blue, red, and infrared light) presented specific effects on the growth and main bioactive metabolites accumulation in A. sinensis, thus, the regulatory effect of combined lights on the growth and metabolites accumulation requires further study.

Angelica sinensis (Oliv.) Diels  /  different light quality  /  growth characteristics  /  bioactive metabolites accumulation  /  gene expression