Impact of cultivation factors in vitro on the growth and the biosynthesis of steviol glycosides in Stevia rebaudiana cell cultures

The growth and the biosynthesis of steviol glycosides (SGs) in Stevia rebaudiana cell cultures subjected to the impact of different cultivation factors were investigated under in vitro conditions. The changes in composition and concentration of constituted components of the nutrient medium was found to exert a significant influence on the of cell culture growth and the biosynthesis of SGs. It was found that combination of growth regulators in the nutrient medium is more important factor for proliferation of isolated cells of S. rebaudiana while the level of SGs accumulation depends to greater extent on genotypical features of cell strain. Light was shown to activate the biosynthesis of SGs, providing evidence for the suggestion about chloroplasts participation in this activation. In morphogenic callus cultures, the content of SGs was about ten times higher, indicating that the level of the accumulation of the compounds in question depends on cell differentiation and specialization.