An Efficient Stevia rebaudiana Transformation System and In vitro Enzyme Assays Reveal Novel Insights into UGT76G1 Function
| Autor: | Hayde Eng, Han-Yi Chen, Christophe La Hovary, Ralph E. Dewey, Rongda Qu, Veronica Vallejo, Qian Wu, Xu Li |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
0301 basic medicine Molecular biology lcsh:Medicine Steviol 01 natural sciences Article 03 medical and health sciences chemistry.chemical_compound Transformation Genetic Stevia lcsh:Science Plant Proteins chemistry.chemical_classification Multidisciplinary biology lcsh:R Glycosyltransferases food and beverages Glycoside Sweetness Plants Genetically Modified biology.organism_classification Isoenzymes Alternative Splicing Transformation (genetics) Stevia rebaudiana 030104 developmental biology Biochemistry chemistry lcsh:Q Plant sciences Function (biology) Biotechnology 010606 plant biology & botany Explant culture |
| Zdroj: | Scientific Reports Scientific Reports, Vol 10, Iss 1, Pp 1-14 (2020) |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/s41598-020-60776-y |
| Popis: | Stevia rebaudiana (Bertoni) is one of a very few plant species that produce zero calorie, sweet compounds known as steviol glycosides (SG). SGs differ in their sweetness and organoleptic properties depending on the number and positioning of sugar groups on the core steviol backbone. There is great interest of modulating the SG profiles of the Stevia plant to enhance the flavor profile for a given application in the food and beverage industries. Here, we report a highly efficient Agrobacterium-mediated stable transformation system using axillary shoots as the initial explant. Using this system, we generated over 200 transgenic Stevia plants overexpressing a specific isoform of UGT76G1. By comparing the SG profiles among independent transgenic events, we demonstrated that altering UGT76G1 expression can change the ratios of specific SG species. Furthermore, using recombinant proteins produced in E. coli, we show that two closely related UGT76G1 isoforms differ in their substrate specificities, providing new insights into mechanisms underlying the diversity of SG profiles that are observed across Stevia germplasm. Finally, we found evidence suggesting that alternative and/or aberrant splicing may serve to influence the ability of the plant to produce functional UGT76G1 transcripts, and possibly produce enzyme variants within the plant. |
| Databáze: | OpenAIRE |
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