The synergistic application of sucrose and various LED light exposures to enhance the in vitro growth of Stevia rebaudiana (Bertoni)

Stevia rebaudiana (Bertoni), a natural zero-calorie sweetener, is approximately 300 times sweeter than sucrose. It holds value in the food industry and pharmaceutical-related sectors. Previous studies have reported numerous pharmacological activities associated with stevia, including its role as an anti-hypertensive, anti-diabetic, anti-inflammatory, anti-tumor, antioxidant, and anti-diarrheal. Consequently, there is a high demand for mass production of its metabolite product. However, stevia produces a limited number of seeds with low viability and germination rates, significantly diminishing plant productivity. Early studies demonstrated that adding sucrose or exposure to various light types improves stevia growth. Despite this, little is known about the combined effect of supplementary sucrose and exposure to various light types on stevia growth. Our results revealed that adding 3% sucrose to the culture media yields the finest growth phenotype. Interestingly, combining supplementary sucrose and light-emitting diode treatments promotes stevia growth, with diverse responses depending on the light spectrum. For instance, white light enhances chlorophyll production, while green light increases plantlet height. Notably, red and blue lights lead to an increase in leaf number and an expansion of leaf size, respectively. Surprisingly, stevia cultivated without additional sucrose under white light treatment displays anisocytic stomata larger than average.