[Molecular cloning and expression analysis of iridoid synthase genes from Rehmannia glutinosa].

Iridoid synthase( IS),the key enzyme in the natural biosynthesis of vegetal iridoids,catalyzes the irreversible cyclization of 10-oxogeranial to epi-iridodial. In this study,we screened the Rehmannia glutinosa transcriptome data by BLASTn with Catharanthus roseus CrIS cDNA,and found four c DNA fragments with length of 1 527,1 743,1 425,1 718 bp,named RgIS1,RgIS2,RgIS3 and RgIS4,respectively. Bioinformatics analysis revealed that the four iridoid synthase genes encoding proteins with 389-392 amino acid residues,protein molecular weights were between 44. 30-44. 74 k Da,and theoretical isoelectric points were between 5. 30 and 5. 87. Subcellular localization predictions showed that the four iridoid synthase were distributed in the cytoplasm. Structure analysis revealed that R. glutinosa iridoid synthases contain six conserved short-chain dehydrogenase/reductase( SDR) motifs,and their 3 D models were composed typical dinucleotide-binding " Rossmann" folds covered by helical C-terminal extensions. Using the amino acid sequences of four R. glutinosa iridoid synthases,phylogenetic analysis was performed,the result indicated that RgIS3,CrIS and Olea europaea OeIS were grouped together,the other R. glutinosa iridoid synthases and fifteen proteins in other plants had close relationship. Real-time fluorescent quantitative PCR revealed that RgIS1 and RgIS3 highly expressed in unfold leaves,however,RgIS2 and RgIS4 highly expressed in stems and tuberous roots,respectively. RgIS3 showed higher expression levels in non-radial striations( nRS) of the two cultivars,and RgIS1 and RgIS2 had higher expression levels in nRS of QH,while RgIS4 had less expression levels in nRS of QH1. RgIS1,RgIS2 and RgIS3 were up-regulated by Me JA treatment,although the time and degree of response differed. Our findings are helpful to reveal molecular function of R. glutinosa iridoid synthases and provide a clue for studing the molecular mechanism of iridoid biosynthesis.

Ethnobotanical approaches of traditional medicine studies in Southwest China: A literature review.

ETHNOPHARMACOLOGICAL RELEVANCE: The ethnopharmacology of Southwest China is extremely interesting because of the region's high level of cultural and medicinal plant diversity. Little work has been done to document the traditional medicinal practices in this area. This review aims to provide an overview of the current knowledge of how medicinal plants in this area are utilized, and conserved, in order to better understand the medicinal flora, identify research gaps, and suggest directions for further research. MATERIAL AND METHODS: A literature review was conducted that included peer reviewed journals, website, books, theses and scientific reports from 1979 to 2014. The distribution and characteristics of medicinal plant knowledge in each province, methods applied in research, and the fluctuations of literature in 5 year intervals were analyzed. The distribution research on different plant groups including fungi, ferns, mosses, and vascular plants were also analyzed. RESULTS AND DISCUSSION: A total of 436 publications from 1979 to 2014 were selected for analysis. References were classified into three stages: discovery stage, utilization stage and conservation stage. Detailed results about the focus of the references, the methods applied, the development and relationship among all folk medicine in Southwest China, Daodi ethnomedicinal resources, Pharmacological studies and Toxicology studies were discussed. While, compared to the rich medicinal flora, the complex demographics and cultural diversity, a large gap still exist to fully understand and document the medicinal flora. CONCLUSIONS: Based on the review results, most research efforts in Southwest China focused on the first step: discovery of traditional usage, geographical distribution, and taxonomy of medicinal species. Only a small percentage of traditional uses or treatments have been tested by modern ethnobotanical approaches. Further research needs to put more emphasis on identifying adulterations, evaluating of Daodi medicine, and elucidating effective compounds from traditional drugs, using molecular and phytochemical approaches. Knowledge on ethnic and cultural aspects of medicinal plant species, to develop effective conservation and sustainable use protocols is lacking.