LED Light Quality Affect Growth, Alkaloids Contents, and Expressions of Amaryllidaceae Alkaloids Biosynthetic Pathway Genes in Lycoris longituba

Abstract

Lycoris longituba is an important ornamental and medicinal plant and contains various Amaryllidaceae alkaloids such as galanthamine (GAL), lycorine (LYC), and lycoramine (LYCM), which have been reported to exhibit medicinal values. However, the effects of light quality on L. longituba are unknown. The present study aimed to explore the effects of different light emitting diode (LED) light quality on growth, physiological characteristics, and alkaloid accumulations in the seedlings. Lycoris longituba seedlings were cultured under different ratios of blue and red LEDs. The results showed that compared to CK, RB (1:2) treatment improved growth, biomass accumulation, and the synthesis of photosynthetic pigments and reduced membrane lipid peroxidation. Blue light increased GAL, LYC, and LYCM contents which were 2.45-, 1.74-, and 1.92-fold higher than CK, respectively. Most of Amaryllidaceae alkaloids biosynthetic pathway genes including PAL, C4H, NBS, TYDC, OMT, and CYP96T1 were upregulated under B treatment. In general, RB (1:2) was the optimal light quality condition for the growth of L. longituba seedlings. B treatment could promote the accumulation of alkaloids and related gene expressions. This study has established the theoretical foundation and technical support for the use of LED light quality control technology in the production of high-quality L. longituba seedlings.