[Systematic identification of chemical forms of key terpene synthase in Cinnamomum camphora].

Cinnamomum camphora is an important economic tree species in China. According to the type and content of main components in the volatile oil of leaf, C. camphora were divided into five chemotypes, including borneol-type, camphor-type, linalool-type, cineole-type, and nerolidol-type. Terpene synthase(TPS) is the key enzyme for the formation of these compounds. Although several key enzyme genes have been identified, the biosynthetic pathway of(+)-borneol, which has the most economic value, has not been reported. In this study, nine terpenoid synthase genes CcTPS1-CcTPS9 were cloned through transcriptome analysis of four chemical-type leaves. After the recombinant protein was induced by Escherichia coli, geranyl pyrophosphate(GPP) and farnesyl pyrophosphate(FPP) were used as substrates for enzymatic reaction, respectively. Both CcTPS1 and CcTPS9 could catalyze GPP to produce bornyl pyrophosphate, which could be hydrolyzed by phosphohydrolase to obtain(+)-borneol, and the product of(+)-borneol accounted for 0.4% and 89.3%, respectively. Both CcTPS3 and CcTPS6 could catalyze GPP to generate a single product linalool, and CcTPS6 could also react with FPP to generate nerolidol. CcTPS8 reacted with GPP to produce 1,8-cineol(30.71%). Nine terpene synthases produced 9 monoterpene and 6 sesquiterpenes. The study has identified the key enzyme genes responsible for borneol biosynthesis in C. camphora for the first time, laying a foundation for further elucidating the molecular mechanism of chemical type formation and cultivating new varieties of borneol with high yield by using bioengineering technology.

[Study on tanshinones regulating root-associated microbiomes of Salvia miltiorrhiza].

The plant root-associated microbiomes include root microbiome and rhizosphere microbiome, which are closely related to plant life activities. Nearly 30% of photosynthesis products of plants are used to synthesize root compounds, there is evidence that root compounds regulate and significantly affect the root microbiome Tanshinones are the main hydrophobic components in Salvia miltiorrhiza. In order to study whether these compounds can regulate the root-associated microbiomes of S. miltiorrhiza, our study first identified a white root S. miltiorrhiza(BG) which contains little tanshinones. Retain of the fifth intron of tanshinones synthesis key enzyme gene SmCPS1 leading to the early termination of the SmCPS1 gene, and a stable white root phenotype. Further, wild type(WT) and BG were planted in greenhouse with nutrient soil(Pindstrup, Denmark) and Shandong soil(collected from the S. miltiorrhiza base in Weifang, Shandong), then high-throughput sequencing was used to analyze the root-associated microbiomes. The results showed that the tanshinones significantly affected the root-associated microbiomes of S. miltiorrhiza, and the impact on root microbiomes was more significant. There are significant differences between WT and BG root microbiomes in species richness, dominant strains and co-occurrence network. Tanshinones have a certain repelling effect on Bacilli which belongs to Gram-positive, while specifically attract some Gram-negative bacteria such as Betaproteobacteria and some specific genus of Alphaproteobacteria. This study determined the important role of tanshinones in regulating the structure of root-associated microbiomes from multiple angles, and shed a light for further improving the quality and yield of S. miltiorrhiza through microenvironment regulation.

[Research progress of natural borneol resources].

Natural borneol is an important traditional Chinese medicine herb with resuscitation-inducing, antipyretic and analgesic effects, and has been widely used in the fields of medicine, perfume and chemical industry. At present, natural borneol is short supply, with promising market development prospects. This paper summarized the distribution of borneol plant resources, cultivation status and molecular biological research progress, in the expectation of providing basis and ideas for the research and application of natural borneol.

Chemical constituents in different parts of seven species of Aconitum based on UHPLC-Q-TOF/MS.

Aconitum L., the main source of Aconitum medicinal materials, is rich in diterpenoid alkaloids. Several drugs derived from diterpenoid alkaloids are widely used to the current clinical treatment of pain, inflammation, and other symptoms. This paper aims to clarify the main metabolites and distribution of diterpenoid alkaloids in different parts of Aconitum plants. To that end, 7 species of Aconitum from three subgenera were analyzed by UHPLC-Q-TOF-MS under identical conditions. The fragmentation regularity of various types of diterpene alkaloids were determined and a total of 126 metabolites were identified by comparing the reference material and secondary mass spectrometry, with the literature. 67, 49, 17, 41, 14, 17 and 21 metabolites were identified from Aconitum carmichaeli, Aconitum stylosum, Aconitum sinomontanum, Aconitum vilmorinianum, Aconitum pendulum, Aconitum tanguticum and Aconitum gymnandrum, respectively. Meanwhile, the structure type of A. carmichaeli, A. stylosum, A. vilmorinianum, A. pendulum, A. gymnandrum were identified as C19 type, A. sinomontanum was C18 type, while A. tanguticum was C20 type. A high similarity of metabolites was found between A. stylosum and A. vilmorinianum. The quantitative analysis of 19 compounds and the relative peak area of all metabolites which obtained through internal standard berberine, highlighted compounds like karakoline, talatisamine and atisine as references for future study of metabolic pathways. Furthermore, results from metabolites distribution and relative peak area analysis suggest that the leaf of A. carmichaeli, the leaf and stem of A. stylosum and A. vilmorinianum, and the flower of A. pendulum have potential as medicinal resources and are worth further development. These results establish a foundation for the comprehensive utilization of Aconitum resources.