Scopolia lurida, a native herbal plant species in Tibet, is one of the most effective producers of tropane alkaloids. However, the tropane alkaloid biosynthesis in this plant species of interest has yet to be studied at the molecular, biochemical, and biotechnological level. Here, we report on the isolation and characterization of a putative short chain dehydrogenase (SDR) gene. Sequence analysis showed that SlTRI belonged to the SDR family. Phylogenetic analysis revealed that SlTRI was clustered with the tropine-forming reductases. SlTRI and the other TA-biosynthesis genes, including putrescine N-methyltransferase (SlPMT) and hyoscyamine 6β-hydroxylase (SlH6H), were preferably or exclusively expressed in the S. lurida roots. The tissue profile of SlTRI suggested that this gene might be involved in tropane alkaloid biosynthesis. By using GC-MS, SlTRI was shown to catalyze the tropinone reduction to yield tropine, the key intermediate of tropane alkaloids. With the purified recombinant SlTRI from E. coli, an enzymatic assay was carried out; its result indicated that SlTRI was a tropine-forming reductase. Finally, the role of SlTRI in promoting the tropane alkaloid biosynthesis was confirmed through metabolic engineering in S. lurida. Specifically, hairy root cultures of S. lurida were established to investigate the effects of SlTRI overexpression on tropane alkaloid accumulation. In the SlTRI-overexpressing root cultures, the hyoscyamine contents were c. 1.7- to 2.9-fold higher than those in control while their corresponding scopolamine contents were likewise elevated. In summary, this functional identification of SlTRI has provided for a better understanding of tropane alkaloid biosynthesis. It also provides a candidate gene for enhancing tropane alkaloid biosynthesis in S. lurida via metabolic engineering.

Rheum species present a significant economic value. Traditional Chinese medicine rhubarb is an important medicinal material in China. It has a long history of use, with a record of use as early as two thousand years ago. Here, we determined the complete chloroplast genome sequences of Rheum nobile and Rheum acuminatum and comprehensively compared them to two other available Rheum cp genomes at the genome scale. The results revealed cp genomes ranging in size from 159,051 to 161,707 bp with a similar typical quadripartite and circular structure. The genome organization, gene numbers, gene order, and GC contents of these four Rheum cp genomes were similar to those of many angiosperm cp genomes. Repeats and microsatellites were detected in the R. nobile and R. acuminatum cp genomes. The Mauve alignment revealed that there were no rearrangements in the cp genomes of the four Rheum species. Thirteen mutational hotspots for genome divergence were identified, which could be utilized as potential markers for phylogenetic studies and the identification of Rheum species. The phylogenetic relationships of the four species showed that the members of Rheum cluster into a single clade, indicating their close relationships. Our study provides valuable information for the taxonomic, phylogenetic, and evolutionary analysis of Rheum.

Rhodiola sacra (Prain ex Hamet) S. H. Fu is a traditional natural plant pharmaceutical with anti-hypoxia effect and mainly distributed in Yunnan and Tibet (China). The complete chloroplast sequence of R. sacra was determined in our study. The cpDNA was 150,941 bp in length, containing a pair of inverted repeats (IRs) of 25,873 bp each separated by a large and small single copy (LSC and SSC) regions of 82,161 bp and 17,034 bp, respectively. The genome contained 84 protein coding genes, eight rRNA genes and 36 tRNA genes. Phylogenetic tree revealed that R. sacra closely related to Rhodiola kirilowii and Rhodiola crenulata.

To detect potential mutations of COL1A1 and COL1A2 genes in four Chinese pedigrees affected with osteogenesis imperfecta (OI) and provide prenatal diagnosis for a fetus at 18th gestational week. All coding regions and exon/intron boundaries of the COL1A1 and COL1A2 genes were analyzed with targeted next-generation sequencing (NGS). Suspected mutations were confirmed with Sanger sequencing in the probands, unaffected relatives and 200 unrelated healthy individuals. Prenatal diagnosis for a high-risk fetus was carried out through Sanger sequencing. The probands of families 1 and 2 have respectively carried a c.760G>A (p.Gly254Arg) and a c.608G>T (p.Gly203Val) mutation of the COL1A1 gene. For family 3, the proband and his daughter have carried a novel c.299-1G>C splicing mutation of the COL1A1 gene. The same mutation was not found in the fetus of this family. For family 4, the proband has carried a novel c.1990G>C (p.Gly664Arg) mutation of the COL1A2 gene. The four mutations were not found in the unaffected relatives and 200 unrelated healthy individuals. The mutations of the COL1A1 and COL1A2 genes probably underlie the disease in the four families. NGS combined with Sanger sequencing can provide an effective and accurate method for their genetic and prenatal diagnosis.

Leontopodium nyingchiense, a new species of Asteraceae from the Xizang (Tibet) Autonomous Region of China, is described and illustrated here. Morphologically, it is most similar to L. lingianum but can be distinguished by the combination of monoecious and dioecious individuals, involucral bracts arranged in 3–5 series (with outer series herbaceous and middle to inner series membranous), fimbriate apices on female florets, rough-edged lobes on male florets, and achenes lacking costae. Phylogenetic analyses further support the separation of this new species from related taxa. Finally, we characterize this new species through both morphological comparisons and molecular analyses.

Based on field surveys, examination of herbarium specimens, and molecular phylogenetic analyses, the present study described a new species, Hydrangea medogensis sp. nov . (Hydrangeaceae), from Medog County, Xizang Autonomous Region, China. Phylogenetic analyses indicated that H. medogensis was placed in Clade 1 as a distinct lineage, sister to the remainder of the clade. Morphologically, the new species is most similar to H. stylosa but can be distinguished by the following key characteristics: fertile flowers with a globose calyx tube constricted at the mouth; calyx teeth triangular, occasionally oblong-ovate, 0.6–1 mm long; adaxial leaf surface covered with two types of soft hairs (long and short); ovary more than 4/5 inferior, nearly completely inferior; and seeds with a very narrow wing around the margin. The taxonomic status of the new species was established based on integrated morphological and molecular evidence.