Elicitor-induced in vitro shoot multiplication and steviol glycosides production in Stevia rebaudiana

Abstract Stevia rebaudiana, which produces the non-caloric natural sweeteners referred to as steviol glycosides (SGs), is a perennial herb native to South America. This study examines the effect of various biotic elicitors, including chitosan (CH) and yeast extract (YE), as well one abiotic elicitor, namely methyl jasmonate (MeJA), on in vitro shoot multiplication and the SGs content of S. rebaudiana. Different concentrations of these elicitors (50, 100, 200, and 300 mg/L) were added to Murashige and Skoog medium that had been supplemented with 2 mg/L 6-benzylaminopurine (BAP). The results showed that both biotic and abiotic elicitors increase shoot multiplication significantly when compared to the basal medium alone. Shoot length and shoot number increased by 70% and 94%, respectively, after adding 200 mg/L CH. Dry weight increased by 51%, 47%, and 36% after adding YE 50, CH 200, and MeJA 100 mg/L, respectively. Interestingly, total SGs content increased with the addition of MeJA 100, CH 200, and YE 50 (by 60%, 44%, and 40%, respectively). Stevioside (ST) and rebaudioside A (Reb A) concentrations, which are the final products of the SGs pathway, were both augmented by the addition of MeJA 100 and CH 200 mg/L. Moreover, these elicitors significantly enhanced the Reb A/ST ratio. Overall, the results indicate that elicitors— CH 200, MeJA 100, and YE 50 mg/L, in particular— can be effective stimulants for the production of biomass and the chemical composition of SGs content of in vitro S. rebaudiana.