PDF(Pubmed)
Abstract：
Stevia rebaudiana (stevia) is a plant in the Asteraceae that contains several biologically active compounds including the antidiabetic diterpene glycosides (e.g. stevioside, rebaudioside and dulcoside) that can serve as zero-calorie sugar alternatives. In this study, an elicitation strategy was applied using 5% polyethylene glycol (PEG), sodium chloride (NaCl; 50 and 100 mM) and gibberellic acid (2.0 and 4.0 mg/L GA3) to investigate their effect on shoot morphogenesis, and the production of phenolics, flavonoids, total soluble sugars, proline and stevioside, as well as antioxidant activity, in shoot cultures of S. rebaudiana. Herewith, the media supplemented with 2 mg/L and 4 mg/L GA3 exhibited the highest shooting response (87% and 80%). The augmentation of lower concentrations of GA3 (2 mg/L) in combination with 6-benzylaminopurine (BAP) resulted in the maximum mean shoot length (11.1 cm). The addition of 100 mM NaCl salts to the media led to the highest observed total phenolics content (TPC; 4.11 mg/g-DW compared to the control 0.52 mg/g-DW), total flavonoids content (TFC; 1.26 mg/g-DW) and polyphenolics concentration (5.39 mg/g-DW) in shoots cultured. However, the maximum antioxidant activity (81.8%) was observed in shoots raised in media treated with 50 mM NaCl. The application of 2 mg/L of GA3 resulted in the highest accumulation of proline (0.99 μg/mL) as compared to controls (0.37 μg/mL). Maximum stevioside content (71 µL/mL) was observed in cultures supplemented with 100 mM NaCl and 5% PEG, followed by the 4 mg/L GA3 treatment (70 µL/mL) as compared to control (60 µL/mL). Positive correlation was observed between GA3 and stevioside content. Notably, these two compounds are derived from a shared biochemical pathway. These results suggest that elicitation is an effective option to enhance the accumulation of steviosides and other metabolites and provides the groundwork for future industrial scale production using bioreactors.
摘要：
甜叶菊（甜叶菊）是菊科中的一种植物，含有几种生物活性化合物，包括抗糖尿病二萜苷（例如甜菊苷，莱鲍迪甙和杜克甙）可以作为零卡路里糖的替代品。在这项研究中,使用5%聚乙二醇(PEG)应用启发策略，氯化钠（NaCl；50和100mM）和赤霉酸（2.0和4.0mg/LGA3），以研究它们对芽形态发生的影响，和酚类物质的生产，黄酮类化合物，总可溶性糖，脯氨酸和甜菊糖,以及抗氧化活性，在S.rebaudiana的射击文化中。随此,添加2mg/L和4mg/LGA3的培养基表现出最高的射击反应（87％和80％）。较低浓度的GA3（2mg/L）与6-苄基氨基嘌呤（BAP）的组合增加导致最大平均芽长度（11.1cm）。向培养基中添加100mMNaCl盐导致观察到的最高总酚含量(TPC;4.11mg/g-DW,与对照0.52mg/g-DW相比)。培养的芽中总黄酮含量（TFC；1.26mg/g-DW）和多酚浓度（5.39mg/g-DW）。然而,在用50mMNaCl处理的培养基中生长的芽中观察到最大的抗氧化活性（81.8％）。与对照（0.37μg/mL）相比，施用2mg/L的GA3导致脯氨酸的最高积累（0.99μg/mL）。在补充有100mMNaCl和5％PEG的培养物中观察到最大甜菊糖苷含量（71µL/mL），然后是4mg/LGA3处理（70µL/mL），与对照（60µL/mL）相比。GA3与甜菊苷含量呈正相关。值得注意的是,这两种化合物来自共同的生化途径。这些结果表明，激发是增强甜菊糖苷和其他代谢物积累的有效选择，并为使用生物反应器的未来工业规模生产提供了基础。
