旭硝子財団助成研究成果報告2018

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Rizkita RachmiEsyanti109Gene Expression Related to Steviol Glycoside Synthesis Produced in Stevia rebaudiana (Bert.) Shoot Culture Induced with Far Red LED Light in TIS RITA®Bioreactor System(Project 2017)74旭硝子財団　助成研究成果報告（2018）Steviol glycosides contained in Stevia leaves have considerable potential uses for natural sweetener industry. To overcome the hindrances in the propagation of Stevia plants using in vivo methods, an alternative technique of propagation using in vitro methods is required. In order to produce a large quantity of stevia biomass in approximately short amount of time, multiplication method using RITA® (Recipient for Automated Temporary Immersion System) can be conducted. One of the limiting factors interfering stevioside production is the formation of flower. This interfering factor could be inhibited by the manipulation on S. rebaudiana culture system using far-red LED light that could also lead to the increase system productivity in terms of higher biomass and steviol glycosides content. The study corresponding to the evaluation of far-red light LED induction effect on steviol contents, biomass growth, and expression levels of several genes related to steviol glycosides and its derivatives synthesis, therefore was conducted in TIS RITA® bioreactor system. Resulted from the experiment conducted, was shown that the biomass in far-red LED RITA® increased by 1.702 ± 0.114 gr compared to control RITA® control (no exposure) which only 0.953 ± 0.093 gr. Plantlet exposed to far-red light LED exhibited an increase of expression levels on ent-KO genes (1.16 times), ent-KS1 (1.27 times), ent-KAH 13 (1.28 times), UGT85C2 (1.25 times), UGT74G1 (1.77 times) and UGT76G1 (1.14 times). The stevioside and rebaudioside-A content analyzed in HPLC were 37.15% and 22.99% higher compared to the planlet cultured in RITA® controls.