Abstract
Plant terpenoids play indispensable roles in primary metabolism as the vital constituents in photosynthesis (chlorophylls, carotenoids and plastoquinones), respiration (ubiquinone) and development regulation (gibberellins, abscisic acid, cytokinin and brassinosteroids). They are also the membrane infrastructural constituent (phytosterols) and protein N-glycosylation participator (dolichols). On the other hand, specific terpenoids, especially C10 monoterpenes and C15 sesquiterpenes, are considered to assume diverse range of ecological functions, examples can be attracting pollinators or seed dispersers, repelling fungal and bacterial pathogens, or acting as phytoalexins that involve in defense against herbivores and surrounding inter/intra species. Some terpenoids are aromatic to humans, making them commercially important in perfumery and cosmetics industry.
The diterpenoid sclareol is the typical precursor for chemical synthesis of substitutes of the precious ambergris, which is highly prized for the pleasant sweet and earthy scent historically. However, the natural provision and price of sclareol fluctuates enormously by the varied yield and quality from its producer plant clary sage (Salvia sclarea). Metabolic engineering is an attractive solution to achieve cost-effective and sustainable production of these valuable terpenoids. In this study, we introduced the sclareol biosynthetic genes into the moss Physcomitrella patens and obtained the novel compound successfully. As a proof-of-concept, the best yield of sclareol was 0.96 μg/mg dry weights (DW) in liquid culture, whereas a larger proportion was released into media that leading to a total production of 2.83 μg/mg DW.
We propose that the sclareol precursor (GGPP) pool is capable of flexibly responding to either PpCPS/KS disruption or the consumption by the heterologous sclareol biosynthetic enzymes. RT-PCR data suggested that enzymatic activity, other than transcription or the GGPP pool, could be the limiting step for higher sclareol production.
The diterpenoid sclareol is the typical precursor for chemical synthesis of substitutes of the precious ambergris, which is highly prized for the pleasant sweet and earthy scent historically. However, the natural provision and price of sclareol fluctuates enormously by the varied yield and quality from its producer plant clary sage (Salvia sclarea). Metabolic engineering is an attractive solution to achieve cost-effective and sustainable production of these valuable terpenoids. In this study, we introduced the sclareol biosynthetic genes into the moss Physcomitrella patens and obtained the novel compound successfully. As a proof-of-concept, the best yield of sclareol was 0.96 μg/mg dry weights (DW) in liquid culture, whereas a larger proportion was released into media that leading to a total production of 2.83 μg/mg DW.
We propose that the sclareol precursor (GGPP) pool is capable of flexibly responding to either PpCPS/KS disruption or the consumption by the heterologous sclareol biosynthetic enzymes. RT-PCR data suggested that enzymatic activity, other than transcription or the GGPP pool, could be the limiting step for higher sclareol production.
| Original language | English |
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| Publisher | Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen |
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| Number of pages | 141 |
| Publication status | Published - 2014 |