Spectral lights influence growth and metabolic efficiency leading to enhanced phytochemical contents of Coriandrum sativum L.

Coriandrum sativum. L (coriander) is an aromatic herb containing valuable bioactive compounds. The current study aimed to understand the role of light quality influence on the metabolic performance of C. sativum. The study was conducted by integrating LED lights viz. red (100 R:0B), red: blue (50 R:50B); blue (0 R:100B), and warm white (WW, served as control). The fresh and dry biomass was highest under 0 R:100B spectral LED lights, whereas the photosynthetic performance was maximum under 50 R:50B LED lights. Among the major vitamins studied, ascorbic acid content was maximized under 50 R:50B spectral LED lights, while α-tocopherol content was highest under 0 R:100B light conditions. Luteolin and umbelliferone, the detected coumarins, exhibited their highest levels under 50 R:50B light spectral composition, however, chlorogenic acid demonstrated its maximum level under 0 R:100B spectral LED lights. C. sativum plants grown under 50 R:50B light displayed a relatively higher content of volatile compounds including, decanal, 2-decenal, 2,6,11-trimethyldodecane, 2-dodecenal, and (E)-tetradec-2-enal. Glucose, fructose, and sucrose identified as the major primary metabolites, were highest under 50 R:50B light. Moreover, the stem and leaf anatomy exhibited the greatest vascularization when influenced by 50 R:50B and 0 R:100B spectral LED lights. Histochemical studies further revealed an intense accumulation of metabolites under the 50 R:50B spectral light conditions. The study also demonstrated the influence of light quality on chloroplast ultrastructure, influencing starch accumulation and providing insights into plant cell metabolic activity through the observed association of chloroplasts with mitochondria. Taken together, the study suggests that 50 R:50B spectral combination could play an important role in augmenting the metabolic performance and phytonutrient outcomes of C. sativum.