LED Light Irradiations Differentially Affect the Physiological Characteristics, Ginsenoside Content, and Expressions of Ginsenoside Biosynthetic Pathway Genes in Panax ginseng

Abstract

Light is essential for plants and plays a vital role in their growth and development. Light irradiation affects the physiological characteristics and synthesis of secondary metabolites in plants. As a semi-shade perennial plant, Panax ginseng C.A. Mey. is sensitive to changes in the light environment. Different light irradiations significantly affect the secondary metabolic processes of P. ginseng. However, few studies have investigated the changes in ginsenoside content in P. ginseng under different light irradiation conditions. In this study, 3-year-old P. ginseng was cultured under white (CK) light, blue (B) light, red (R) light, green (G) light, and natural light (NL) to explore the effects of light irradiation on the physiological characteristics and ginsenoside secondary metabolism of P. ginseng. The B and CK treatments significantly increased the photosynthetic level in P. ginseng leaves. The total saponin content under blue and red light treatments increased by 28.81% and 21.64%, respectively, compared with the CK treatment. Blue and red light improved the transcription levels of ginsenoside biosynthetic pathway genes. Blue light upregulated the expression of HMGR, SS, SE, DS, CYP716A52, and CYP716A47, and the expression of HMGR, SS, SE, DS, and CYP716A47 under red light treatment was significantly upregulated in P. ginseng roots. Principal component and correlation analyses revealed that the physiological and ecological processes of P. ginseng exhibited different responses to light irradiation. The total saponin content in the roots was positively correlated with the content of protopanaxatriol -type ginsenosides and water use efficiency in leaves. Our study indicates that light conditions can be improved by blue and red light or by blue and red film covering to facilitate the accumulation of saponin during the ecological cultivation of P. ginseng.

Harnessing postharvest light emitting diode (LED) technology of Centella asiatica (L.) Urb. to improve centelloside content by up-regulating gene expressions in the triterpenoid pathway

“…root under blue LEDs (450 nm and 470 nm) combined with dark condition. Blue LED treatment stimulated key enzymes in the isoprenoid pathway (such as squalene synthase) by inducing the generation of reactive oxygen species (ROS) which triggered the expression of several defense genes and the synthesis of ginsenosides [ 29 , 34 ]. Therefore, blue LEDs play an important role by triggering the triterpenoid pathway, as summarized and illustrated in Fig.…”

Growth and Photosynthetic Responses to Increased LED Light Intensity in Korean Ginseng (Panax ginseng C.A. Meyer) Sprouts

“…Light intensity is one of the most important light components that significantly affects plant photosynthesis and dictates the ginseng production capacity [8,17,25]. It is widely recognized that the ginseng responses to various light regimes (radiations and intensities) depend on the ginseng ages and cultivars, as well as on environmental factors [14,[26][27][28]. The responses of PGSs regarding the physiology, morphology, and photosynthesis aspects to the light intensity are still speculative.…”