Analysis of transcriptomes to explore genes contributing to iridoid biosynthesis in Gentiana waltonii and Gentiana robusta (Gentianaceae) / 药学学报

The roots and flowers of Gentiana waltonii and Gentiana robusta are used as Tibetan herb Jie-Ji in traditional Tibetan medicine, with iridoids as the main active ingredient and index components. To study the pathway of iridoid biosynthesis, roots, stems, leaves and flowers of G. waltonii and G. robusta were subjected to a high-throughput transcriptomic sequencing analysis by Illumina HiseqXTen. After removing insignificant reads and de novo splicing, 79 455 and 78 466 unigenes were obtained from G. waltonii and G. robusta respectively, with average length as 834 bp and 862 bp. The unigene GO functions could be divided into three categories of 65 branches. The unigenes were aligned in KOG database and were classified into 25 classes according to function. In KEGG database, 315 and 340 unigenes of G. waltonii and G. robusta were implicated in 20 standard secondary metabolic pathways, respectively. Furthermore, 80 and 57 unigenes of the two species were analyzed to encode 24 key enzymes in the pathway related to iridoid biosynthesis. There were differences in gene expression among different organs. Based on sequence data, significant amounts of SSRs, SNPs and InDels were detected in each dataset. This study provides a platform for further development of molecular markers, excavation of functional genes, and research into metabolic pathways and their regulatory mechanism within G. waltonii and G. robusta.

Taxonomic identification of Tibetan herb Bawo Sebo and its chloroplast genome structure / 药学学报

As a common Tibetan herb, Bawo Sebo was mainly used in the treatment of rheumatoid arthritis and urarthritis in Traditional Tibetan medicine. Based on our ethnobotanical survey, the origin of the herb was determined as Swertia verticillifolia T. N. Ho et S. W. Liu (Gentianaceae), endemic to the region of the Qinghai-Tibet Plateau. The diagnostic characters:perennial; stem leaves in whorls; corolla campanulate, yellow-green, 4-lobed; nectary 1 per corolla lobe, naked. Also, its complete chloroplast (cp) genome was sequenced. It is 151 682 bp in length, including a large single copy (LSC) region of 82 623 bp, a small single copy (SSC) region of 18 335 bp and a pair of inverted repeats (IRs) of 25 362 bp. It contains 129 unique genes, including 84 protein-coding genes, 37 tRNAs and 8 rRNAs. This study provides information for understanding the diversity of Swertia cp genomes, and the alpine species identification, conservation and molecular phylogenetic researches of Swertia and Gentianaceae.

Studies on genetic diversity of three Tibetan herbs / 中国中药杂志

The genetic diversity of three Tibetan herbs, i. e., Sang-Di, E-Dewa and Ye-Xingba (Tibetan names), was studied based on the field collection, specimen identification and DNA sequence analysis. Swertia hispidicalyx, Gentiana lhassica and Scrophularia dentata, as the original plants of the three Tibetan herbs, were collected and identified. The regions of ITS, matK, rbcL, rpoC1, trnL(UAA), psbA-trnH, atpB-rbcL, trnS (GCU)-trnG(UCC), rpl20-rps12, trnL(UAA)-trnF(GAA) and nadl 2nd intron were amplified and sequenced. The ITS regions of S. hispidicalyx and S. dentata were cloned and sequenced, and the sequences were classified into different genotypes. All the sequences were analyzed and compared with those of closely related species. Our studies may provide reference for the genetic diversity analysis and molecular identification of the three Tibetan herbs.

Simultaneous determination of five iridoids in gentianae macrophyllae radix and their local variety by HPLC / 中国中药杂志

This study aims to establish a new method for quality evaluation of Gentianae Macrophyllae Radix by simultaneous determination of five iridoids (loganic acid, 6'-O-beta-D-glucopyranosylgentiopicroside, swertiamarin, gentiopicroside, sweroside), and to detect five iridoids in the root of eight species (Gentiana macrophylla, G. straminea, G. crassicaulis, G. dahurica, G. robusta, G. waltonii, G. lhassica, and G. tibetica). The separation was carried out on a Shiseido SPOLAR C18 (4.6 mm x 250 mm, 5 microm) column eluted with mobile phase of water containing 0.04% formic acid (A) and acetonitrile (B) in a gradient program. The flow rate was 0.8 mL x min(-1). The detect wavelength was set at 240 nm. The column temperature was kept at 30 degrees C. The volume of injection was 5 microL. The five iridoids were well separated with ideal linear correlations. The average recoveries were 97.35% - 106.23%. All the five iridoids were detected in the root of eight species. The contents of same species changed in a somewhat wider range. The contents in root of G. dahurica were lower than that in other species.

Roots of pioneer trees in the lower sub-tropical area of Dinghushan, Guangdong, China / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Representative pioneer tree root systems in the subtropical area of South China were examined with regard to their structure, underground stratification and biomass distribution. Excavation of skeleton roots and observation of fine roots of seven species including the Euphorbiaceae, Theaceae, Melastomataceae, Lauraceae and Fagaceae families was carried out. The results showed that: (1) Pioneer tree roots in the first stage of natural succession were of two types, one characterized by taproot system with bulky plagiotropic branches; the other characterized by flat root system with several tabular roots. The late mesophilous tree roots were characterized by one obvious taproot and tactic braches roots up and down. Shrub species roots were characterized by heart fibrous root type featured both by horizontally and transversally growing branches. Root shapes varied in different dominant species at different stages of succession. (2) Roots of the different species varied in the external features-color, periderm and structure of freshly cut slash. (3) In a set of successional stages the biomass of tree roots increased linearly with the age of growth. During monsoon, the total root biomass amounted to 115.70 t/ha in the evergreen broad-leaved forest; 50.61 t/ha in needle and broad-leaved mixed forest dominated by coniferous forest; and 64.20 t/ha in broad-and needle-leaved mixed forest dominated by broad-leaved heliophytes, and are comparable to the underground biomass observed in similar tropical forests. This is the first report about roots characteristics of forest in the lower sub-tropical area of Dinghushan, Guangdong, China.