Daminozide enhances the vigor and steviol glycoside yield of stevia (Stevia rebaudiana Bert.) propagated in temporary immersion bioreactors

Stevia (Stevia rebaudiana Bertoni) produces steviol glycosides (SG), a group of diterpenoid secondary metabolites widely used as natural sweeteners. SGs share the same precursor with gibberellins (GAs), ent-kaurenoic acid. In this study, we attempted to increase SG content in stevia propagated Temporary Immersion Bioreactors (TIBs) by blocking acid entry GA synthesis pathway using Daminozide (0, 10, 20 ppm), known inhibitor. The maximum biomass weight and (up 40% for stevioside rebaudioside A) was observed following 10 ppm treatment. treatment also increased transcript accumulation genes involved biosynthesis, such SrKA13H, SrUGT85C2, SrUGT76G1, indicating that became more active due inhibition. Furthermore, inhibition inhibitor exposure indicated upregulated expression biosynthesis gene (GA3ox) feedback regulation, downregulated catabolism (GA2ox2) result feed-forward regulation. This study reports impact late-stage chemical modulation yield from vitro culture; pathways are related.