Trans-isopentenyl diphosphate synthases (TIDSs) genes are known to be important determinants for terpene diversity and the accumulation of terpenoids. The essential oil of Cinnamomum camphora, which is rich in monoterpenes, sesquiterpenes, and other aromatic compounds, has a wide range of pharmacological activities and has therefore attracted considerable interest. However, the TIDS gene family, and its relationship to the camphor tree (C. camphora L. Presl.), has not yet been characterized. In this study, we identified 10 TIDS genes in the genome of the C. camphora borneol chemotype that were unevenly distributed on chromosomes. Synteny analysis revealed that the TIDS gene family in this species likely expanded through segmental duplication events. Furthermore, cis-element analyses demonstrated that C. camphora TIDS (CcTIDS) genes can respond to multiple abiotic stresses. Finally, functional characterization of eight putative short-chain TIDS proteins revealed that CcTIDS3 and CcTIDS9 exhibit farnesyl diphosphate synthase (FPPS) activity, while CcTIDS1 and CcTIDS2 encode geranylgeranyl diphosphate synthases (GGPPS). Although, CcTIDS8 and CcTIDS10 were found to be catalytically inactive alone, they were able to bind to each other to form a heterodimeric functional geranyl diphosphate synthase (GPPS) in vitro, and this interaction was confirmed using a yeast two-hybrid assay. Furthermore, transcriptome analysis revealed that the CcTIDS3, CcTIDS8, CcTIDS9, and CcTIDS10 genes were found to be more active in C. camphora roots as compared to stems and leaves, which were verified by quantitative real-time PCR (qRT-PCR). These novel results provide a foundation for further exploration of the role of the TIDS gene family in camphor trees, and also provide a potential mechanism by which the production of camphor tree essential oil could be increased for pharmacological purposes through metabolic engineering.
The high-voltage isolated energy supply transformer (HIET) is the key component of the HVDC breaker, which is used for energy transmission and the potential isolation. There is a lack of research results that can meet engineering applications at home and abroad. The design of a 500 kV HIET with dry-type insulation is proposed, using 10 cascade connected 50 kV sub-transformers (STs), which uses silicon rubber suitable for DC voltage as the main insulation material. High-voltage (HV) winding of ST adopts double-shielding structure of coil semi-conductive shielding and inner semi-conductive shielding to improve electric field distribution. The simulation analysis of an electric field at different insulation thicknesses and temperatures shows that the electric field decreases with an increase in thickness of insulation. When the thickness is greater than 25 mm, the electric field reduction effect is significantly weakened. The electric field is closely related to temperature, when at 20°C, the electric field between double-shielding is relatively uniform. When at 70°C, the inner shielding electric field is much higher than coil shielding, and undergoes obvious reversal. In addition, the 500 kV HIET's electric field has been analysed. The 50 0kV HIET prototype has been manufactured and passed the type test, and successfully applied to the 500 kV Zhangbei DC grid project.This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.