Combination of white and green/red LED lights influence growth, antioxidant properties, mineral composition and ginsenosides content of Panax ginseng sprouts in controlled environment system

Abstract

The spectral quality of light regulates plant growth through a variety of physiological, biochemical, and molecular processes. Earlier research on ginseng sprouts have largely focused on the impact of monochromatic lights, with limited attention to combinations with white light. The present study explored the influence of white light supplemented with different wavelengths on ginseng sprout growth at both low (30) and high (200) µmol m^− 2 s^− 1 PPFD intensities. Significant variations in growth were noted between the two light intensities. Specifically, the green light combination proved advantageous for enhancing both growth and photosynthesis across both intensity levels. The chlorophyll fluorescence characteristics, stomatal properties, total soluble sugars, total soluble proteins, and root activity were notably enhanced by W + G (200 PPFD) treatment. Enzymatic and non-enzymatic antioxidant activities were predominantly influenced by W + R treatments at both intensity levels. Low light, particularly, W + R (30 PPFD) and W + G (30 PPFD) significantly increased mineral content in both the shoot and root. Low light intensities positively influenced the accumulation of ginsenosides Rd, F₂, and Rg₁ in treatments W, W + R, and W + G, respectively while Rd₂ accumulation was greatly promoted by high intensity white light treatment, W (200 PPFD). Gene expression involved in the ginsenoside biosynthesis pathway aligned with ginsenoside accumulation. Therefore, to meet the growing demand for ginseng sprouts, optimizing light quality, particularly by incorporating green or red light in conjunction with white light, might serve as a promising approach for enhancing both the quality and yield of ginseng sprouts within the controlled environment agriculture system.