Cloning and functional analysis of IPI gene from Fritillaria unibracteata Hsiao et K. C. Hsia / 药学学报

An open reading frame (ORF) of isopentenyl-diphosphate delta isomerase gene (FuIPI) was cloned from Fritillaria unibracteata Hsiao et K. C. Hsia. (F. unibracteata). Furthermore, the bioinformatics and functional analyses of FuIPI were performed in this study. The result showed that, the ORF of FuIPI gene was 825 bp, encoding a polypeptide of 274 amino acids in length, with a relative molecular mass of about 31 kD and a theoretical isoelectric point of 5.61. Sequence analysis showed that FuIPI contained conserved structural domains and key residues involved in the catalyzing process. The phylogenetic analysis exhibited that FuIPI was closely related to IPIs of Dendrobium officinale and Musa acuminate. Real-time PCR analysis showed that FuIPI was distributed in different tissues of F. unibracteata, but had the highest transcriptional level in leaves, followed by stems, bulbs, and flowers. Furthermore, the FuIPI protein was successfully expressed in Escherichia coli BL21(DE3). The purified FuIPI protein successfully catalyzed the conversion from isopentenyl diphosphate (IPP) to dimethylallyl pyrophosphate (DMAPP). The above results provided a theoretical basis for further investigation of the molecular role of FuIPI in the biosynthesis of alkaloids.

Analysis of chloroplast genomes and development of specific DNA barcodes for identifying the original species of Rhei Radix et Rhizoma / 药学学报

Rhei Radix et Rhizoma is one of the most used medicinal materials in China. Its original species are Rheum palmatum, Rh. tanguticum, and Rh. officinale. Rhei Radix et Rhizoma derived from different original species are significantly different in their active ingredients and pharmacological effects. To develop an accurate, rapid, and specific identification method, we obtained the chloroplast genomes of the three original species by Illumina Novaseq sequencing. We designed specific DNA barcodes from the hypervariable regions, which can accurately identify the three original species. The experimental results showed that the total length of the chloroplast genomes of Rh. tanguticum, Rh. officinale and Rh. palmatum were 161 039 bp, 161 093 bp, and 161 136 bp, respectively. All the three genomes were represented as typical quadripartite structures. A total of 131 genes, including 86 protein-coding genes, 37 transfer RNA (tRNA) genes, and eight ribosomal RNA (rRNA) genes were identified from each chloroplast genome. Five pairs of primers based on the hypervariable regions were designed to efficiently amplify 42 samples. Results confirmed that five hypervariable regions, rps16-trnQ, psaA-ycf3, psbE-petL, ndhF-rpl32, and trnT-trnL, can be used as specific DNA barcodes for the identification of Rh. tanguticum, Rh. officinale, and Rh. palmatum. These results provided genetic information for further species identification of Rhei Radix et Rhizoma, and improve the safety of this clinical medication as well as standardize the market for Rhei Radix et Rhizoma.

Identification of Fritillaria taibaiensis and its relatives by real-time PCR with a TaqMan-MGB probe / 药学学报

The molecular identification of Fritillaria taibaiensis and its relatives was studied by real-time PCR with a TaqMan-MGB probe. DNA was extracted from F. taibaiensis and its relatives. According to the sequence of ITS1 region, the mutation sites of F. taipaiensis and its related species were identified by MEGA7.0 software. The specific primers (a pair) and a TaqMan-MGB probe were designed by Primer Premier 6.0 software. In the Roche LightCycler 96 system, the lowest limit of detection for F. taipaiensis DNA template was 0.002 39 ng·μL-1, and the optimal Tm value range was 60 and 61 ℃. Specificity identification showed that the method had good specificity for F. taipaiensis, as it could be distinguished from other 13 different Fritillaria species including F. unibracteata. Since this method could accurately identify F. taipaiensis and its related species, it provides technical support for rational development of F. taipaiensis resources, management of Chinese medicinal market and supervision of raw materials in Chinese medicine manufacturing enterprises.

Research progress in original species identification in industry chain of Rhei Radix et Rhizoma / 中国中药杂志

Rhei Radix et Rhizoma is a kind of commonly used Chinese medicinal materials. Due to the overharvesting, the wild resource is endangering. Large market demand caused severely adulterant of commercial Rhei Radix et Rhizoma medicinal materials and decoction pieces. This manuscript reviewed the advances of the original species authentication in the industrial chain of Rhei Radix et Rhizoma during the latest decade, including characteristics and microscopic features, phytochemical analysis on anthraquinones, and molecular authentication based on DNA barcoding. Accordingly, an original species authentication route for the industrial chain of Rhei Radix et Rhizoma was summarized:(1)the identification of seeds and seedlings by DNA barcoding;(2) the selection of high variable sites based on the chloroplast genome;(3)biomonitoring of the Rhei Radix et Rhizoma medicinal materials and decoction pieces by two-dimensional DNA barcode;(4)traceability of Chinese patent medicines by third-generation sequencing. In conclusion, the combination of molecular identification and traditional identification methods provides a new idea for the identification of the original species of Rhei Radix et Rhizoma in the industrial chain and a essential guidance for the research of drug safety and efficacy of Rhei Radix et Rhizoma.

Molecular identification and genetic relationship of Fritillaria cirrhosa and related species based on DNA barcode / 药学学报

Based on the ITS2 and psbA-trnHsequences, molecular biological identification and genetic relationship of Fritillaria cirrhosa with its relative species were carried out. In this paper, the PCR-RFLP method specified by the Chinese Pharmacopoeia was performed on all samples at first. Secondly, the ITS2 and psbA-trnH sequences of all samples were amplified. Then, the amplified products were used to analyze the genetic distance, construct the phylogenetic tree, assess the identification efficiency, and evaluate the genetic relationship as well. The result showed that all the samples were divided into two groups by PCR-RFLP method. The samples in the first group, including Fritillaria ussuriensis, Fritillaria thunbergii and Fritillaria pallidiflora, could not be digested by SmaI, while the other samples in the second group, including Fritillaria mellea, Fritillaria sinica, Fritillaria cirrhosa var. ecirrhosa Franch, Fritillaria unibracteata var. longinectarea and Fritillaria cirrhosa, could be digested by SmaI. Then, ITS2 and psbA-trnH sequences of all samples were obtained. The length of various ITS2 sequences were distributed from 235 to 239 bp, and the average intra- and inter-specific genetic distance were 0.001 and 0.022, respectively. NJ tree showed that all samples were separated into "Northern Fritillaria" group (Fritillaria ussuriensis and Fritillaria pallidiflora) and "Southern Fritillaria" group (Fritillaria thunbergii, Fritillaria mellea, Fritillaria sinica, Fritillaria cirrhosa var. ecirrhosa Franch, Fritillaria unibracteata var. longinectarea and Fritillaria cirrhosa). The latter group could be further divided into Fritillaria thunbergii and Fritillaria cirrhosa subgroup, and the species in Fritillaria cirrhosa subgroup had close phylogenetic relationships. The length of psbA-trnH sequences was distributed from 337 to 373 bp, and the intra- and inter-specific genetic distance were 0.263 and 0.329, respectively. The samples in this paper could not be clustered effectively by NJ tree. This indicated that the ITS2 sequences were not only able to identify Fritillaria cirrhosa with its partial relative species quickly and accurately, but also clarify the relationship between different Fritillaria species. Therefore, it provided an important theoretical foundation for the development of molecular markers, effective protection, and rational development and utilization of Fritillaria resources.