Multifunctional oxidosqualene cyclases and cytochrome P450 involved in the biosynthesis of apple fruit triterpenic acids
© 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1979. - 211(2016), 4 vom: 21. Sept., Seite 1279-94 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2016
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Malus × domestica apple betulinic acid cytochrome P450 germanicol oxydosqualene cyclase triterpene ursolic acid mehr... |
| Zusammenfassung: | © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust. Apple (Malus × domestica) accumulates bioactive ursane-, oleanane-, and lupane-type triterpenes in its fruit cuticle, but their biosynthetic pathway is still poorly understood. We used a homology-based approach to identify and functionally characterize two new oxidosqualene cyclases (MdOSC4 and MdOSC5) and one cytochrome P450 (CYP716A175). The gene expression patterns of these enzymes and of previously described oxidosqualene cyclases were further studied in 20 apple cultivars with contrasting triterpene profiles. MdOSC4 encodes a multifunctional oxidosqualene cyclase producing an oleanane-type triterpene, putatively identified as germanicol, as well as β-amyrin and lupeol, in the proportion 82 : 14 : 4. MdOSC5 cyclizes 2,3-oxidosqualene into lupeol and β-amyrin at a ratio of 95 : 5. CYP716A175 catalyses the C-28 oxidation of α-amyrin, β-amyrin, lupeol and germanicol, producing ursolic acid, oleanolic acid, betulinic acid, and putatively morolic acid. The gene expression of MdOSC1 was linked to the concentrations of ursolic and oleanolic acid, whereas the expression of MdOSC5 was correlated with the concentrations of betulinic acid and its caffeate derivatives. Two new multifuntional triterpene synthases as well as a multifunctional triterpene C-28 oxidase were identified in Malus × domestica. This study also suggests that MdOSC1 and MdOSC5 are key genes in apple fruit triterpene biosynthesis |
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| Beschreibung: | Date Completed 26.01.2018 Date Revised 13.12.2023 published: Print-Electronic GENBANK: EB148173, FJ032006, FJ032008, KT383435, KT383436 Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.13996 |