Response of bioactive phytochemicals in in vitro shoot cultures of Gardenia jasminoides, Variegata to fluorescent light as a physical elicitor

An assessment was conducted on the impact of white, red, blue, and green fluorescent lighting on the fresh weight and production of bioactive phytochemicals in the shoot cultures of Gardenia jasminoides, Variegata. In both harvests, the shoot cultures exposed to blue fluorescent light had the maximum fresh weight (1.84 ± 0.16 and 2.413 ± 0.13 g, respectively). In contrast, the fresh weight measurements for both harvests (0.945± 0.055, 1.42± 0.2, respectively) were lowest under white fluorescent light. The shoot cultures that were exposed to green light for two weeks (first harvest) and four weeks (second harvest) showed the highest total flavonoid content (1.02 ± 0 mg / g dw) and total phenolic content (11.19 ± 0.43 mg / g dw), respectively. The shoot cultures exposed to blue light showed the highest level of antioxidant activity. Regarding the influence on the content of secondary metabolites, it is clear that only three phenolic compounds—chlorogenic acid, rosmarinic acid, and rutin—were found in variable amounts throughout various harvests and treatments. First, the extracts of shoots exposed to red light for two weeks (first harvest) had the highest concentration of chlorogenic acid (840±1.4 µg/g dw), followed by shoots exposed to green light for two weeks (first harvest) (835±1.6 µg/g dw). In the second harvest (four weeks), the white light yielded the highest rosmarinic acid concentration (3965± 3 µg / g d w), while the red light yielded the lowest quantity (3175± 1.5 µg / g d w). Regarding rutin, it was noted that the green light in the second harvest possessed the highest rutin concentration (1800± 3, 1515±3 µg/g d w, respectively), with the green light in the first harvest coming in second.