Effect of Gibberellic Acid on Production of Biomass, Polyphenolics and Steviol Glycosides in Adventitious Root Cultures of Stevia rebaudiana (Bert.)

Abstract

In current study, the effect of gibberellic acid was tested for production of biomass, polyphenolics and Steviol glycosides in adventitious root cultures of Stevia rebaudiana. Adventitious cultures were induced from the roots of in vitro grown plantlets on Murashige and Skoog (MS) medium containing combination of gibberellic acid (GA3; 0.5, 1.0, 1.5 and 2.0 mg/L) and naphthalene acetic acid (NAA; 0.5 mg/L). Initially, a known mass of inoculum roots were shifted into suspension media augmented with various GA3 concentrations. The growth behavior of adventitious roots was recorded every 3 days for a period of 30 days. Maximum biomass biosynthesis (13.12 g/flask) was noticed in exponential phase on 27th day in the suspension containing 2.0 mg/L of GA3. Other GA3 concentrations also displayed optimum patterns of biomass accumulation as compared to the control. Adventitious roots were investigated for total phenolic content (TPC) and production (TPP), total flavonoid content (TFC) and production (TFP), and 1, 1-diphenyl-2-picrylhydrazyl (DPPH)-based antioxidant potential. Maximum phenolics (TPC 9.84 mg gallic acid equivalent (GAE)/g-dry weight (DW)) and TPP (147.6 mg/L), TFC (5.12 mg Quercitin equivalent (QE)/g-DW) and TFP (76.91 mg/L) were observed in 2.0 mg/L GA3 treated cultures. The same concentration of gibberellic acid enhanced antioxidant activity (77.2%). Furthermore, maximum stevioside (7.13 mg/g-DW), rebaudioside-A (0.27 mg/g-DW) and dulcoside-A (0.001 mg/g-DW) were observed in roots exposed to 2.0 mg/L GA3. This is the first report on the application of GA3 on biomass accumulation and secondary metabolite production in S. rebaudiana. The current study will be helpful to scale up the adventitious root cultures in bioreactors for the production of biomass and pharmaceutically important secondary metabolites.

Elicitation of Submerged Adventitious Root Cultures of Stevia rebaudiana with Cuscuta reflexa for Production of Biomass and Secondary Metabolites

“…The in vitro cultures are trustworthy for the production of biomass and secondary metabolites due to the homogenous growth of cells in contrast to wild plants, which are exposed to multiple and variable environmental conditions that may cause fluctuation in the synthesis of biomass and important metabolites [ 49 ]. Furthermore, the selection of a proper explant also plays a key role in culture development and the synthesis of metabolites because the polyphenolics are not restricted to specific parts in wild species but rather multiple organs of wild plants [ 1 , 2 ]. In previous studies, the exposure of Stevia in vitro cultures to 0, 20, 40, 60, and 80 mM concentrations of salt (NaCl) negatively regulated the growth of Stevia plants [ 50 ].…”

“…It is commonly known as sweet leaf or sugar leaf due to its sweet taste [ 1 ]. The Stevia rebaudiana is famous for its sweet taste due to the chemical compounds present in the leaves of Stevia such as Steviol glycosides, which commonly includes steviosides and rebaudioside-A contents [ 2 ]. Eupatorium rebaudianum Bertoni was given the first name to Stevia rebaudiana [ 3 ].…”

Synthesis and production of steviol glycosides: recent research trends and perspectives

“…Recently, a new approach has been described to synthesize stevioside, rebaudioside A, and dulcoside A by adventitious roots of Stevia rebaudiana cultured in media supplemented with gibberellic acid (Ahmad et al 2020 ). The novelty of these studies is that adventitious roots are induced from the roots of seedlings grown in vitro and, as it is known so far, SvGls are not produced by the root cells.…”

A Novel Bacillus safensis-Based Formulation along with Mycorrhiza Inoculation for Controlling Alternaria alternata and Simultaneously Improving Growth, Nutrient Uptake, and Steviol Glycosides in Stevia rebaudiana under Field Conditions

“…The glycosylation of steviolbioside’s C-4 carboxylic acid by the UGT74G1 enzyme results in the synthesis of stevioside [ 7 ]. Afterward, rebaudioside-A is formed by the addition of a D-glucose molecule of stevioside, catalyzed by the UGT76G1 enzyme [ 11 ]. There are a few reports available on the impact of biomolecules, such as gibberellin, salicylic acid (SA), and chitosan, on gene expression associated with SGs biosynthesis in stevia crop [ 10 , 11 ] Some work has been done on the direct growth promotion of stevia using arbuscular mycorrhizal fungi (AMF) [ 12 ].…”

“…Afterward, rebaudioside-A is formed by the addition of a D-glucose molecule of stevioside, catalyzed by the UGT76G1 enzyme [ 11 ]. There are a few reports available on the impact of biomolecules, such as gibberellin, salicylic acid (SA), and chitosan, on gene expression associated with SGs biosynthesis in stevia crop [ 10 , 11 ] Some work has been done on the direct growth promotion of stevia using arbuscular mycorrhizal fungi (AMF) [ 12 ]. However, there is no research available concerning the role of plant growth-promoting rhizobacteria (PGPR) in the regulation of SGs, metabolite content, growth, biochemical aspects, and management of phytopathogens of stevia.…”