Cloning and expression analysis of RcUDPGTs genes in Tibetan Rhodiola crenulata / 药学学报

UDP glucosyltransferase (UDPGT) catalyzes the synthesis of secondary metabolites and plant hormones to regulate plant growth and development, pathogen defense and environmental adaptability. In this study 18 members of the RcUDPGT gene family were cloned from Tibetan Rhodiola crenulata and analyzed using bioinformatics. The tissue-specific expression, abiotic stresses and plant hormones (abscisic acid, auxin, methyl jasmonate) induced expression patterns were identified by real-time quantitative PCR. The bait vector of RcUDPGT (JX228125.1) was constructed to select interacting proteins from an Arabidopsis yeast library. The results of the bioinformatics analysis revealed that RcUDPGT nucleotide sequences were about 1 400 bp and encoded 452-498 amino acids. In the primary protein sequences, C-terminal sequences were more conserved compared with N-terminal regions, which held a PSPG (plant secondary product glycosyltransferase) domain. In the tertiary structures, RcUDPGTs contained a UDP sugar donor recognition binding site. In addition, all genes had multiple phosphorylation sites. The results of qRT-PCR showed that RcUDPGTs genes were expressed in root, stem and leaf. The expression levels were regulated by low temperature/ultraviolet light and various plant hormones (ABA, IAA, MeJA), but the expression patterns were quite different among them. For example, RcUDPGT6, RcUDPGT11, and RcUDPGT17 had the highest expression in leaves and were induced by all three hormones, suggesting that the functions of these genes might be to respond to environmental changes. RcUDPGT9, RcUDPGT10, RcUDPGT14 were most abundantly expressed in roots and were significantly induced by ABA and MeJA hormones, indicating that these genes may be involved in the synthesis and accumulation of salidroside. Yeast two-hybrid results showed that RcUDPGT did not exhibit autoactivation and cell toxicity, and two significant interactional genes were identified, AtKCR1 (AT1G67730.1) and AtSNL4 (AT1G70060). The AtKCR1 gene encodes a β-ketoacyl reductase (KCR) involved in synthesis of very long chain fatty acids. The AtSNL4 gene encodes a homolog of the transcriptional repressor SIN3, which could participate in the ABA hormone signaling pathway and enhance the transcriptional repression of AP2/EREBP class factors in Arabidopsis. These results suggest that the accumulation of the secondary metabolite salidroside in Rhodiola crenulata might be affected by several regulatory mechanisms. The above results may lay the foundation for understanding the adaptive mechanism of Rhodiola crenulata in a high altitude environment and stimulate an in-depth study of the synthesis and accumulation of secondary metabolites in this species.

Analysis on genetic diversity of different Salvia miltiorrhiza geographical populations in China / 中国中药杂志

<p><b>OBJECTIVE</b>To research on genetic diversity of different Salvia miltiorrhiza geographical populations in China.</p><p><b>METHOD</b>The genetic diversity of 27 S. miltiorrhiza geographical populations from ten provinces in China was estimated using amplified fragment length polymorphism (AFLP) markers. The data of amplified bands were analyzed by the software POPGENE and SPSS.</p><p><b>RESULT</b>The ten primers employed produced a total of 528 discernable and reproduceable amplified fragments. There were 476 polymorphic brands. The percentage of polymorphic bands with in different populations was 90.15%. Genetic diversity analysis showed that Neis gene diversity (He) was 0.261 2 and Shannon's genetic diversity index (1) was 0.403 3. The coefficient of gene similarity was 0.504 0-0.789 0 between populations. The cluster map including all samples were obtained by UPGMA. In the map, there were seven cluster groups and one individual outside the groups.</p><p><b>CONCLUSION</b>The genetic diversity with in different geographical population of S. miltiorrhiza in China is plentiful.</p>

Studies on cytogeography of Pinellia ternata poliploid complex / 中国中药杂志

<p><b>OBJECTIVE</b>In order to clarify the genetic background of Pinellia ternata germplasm resources in China, the chromosomal constitution and cytogeographical distribution of P. ternata were investigated in 27 different populations among 16 provinces and regions in China systematically.</p><p><b>METHOD</b>Cytological and cytogeographical methods were used in the study.</p><p><b>RESULT</b>P. ternata in China is a polyploid complex, which contains septuploid (2n = 7x = 91) , octoploid (2n = 8x = 104) , nonuploid (2n = 9x = 117) and decaploid (2n = 10x = 130). Meanwhile the aneuploid series (2n = 92, 103, 105, 115) of a minority of P. ternata were also found.</p><p><b>CONCLUSION</b>The genetic differentiation and the phenomenon of ploidy miscellany commonly exist in the species of P. ternata in China, both for natural populations and cultivated populations. Toxicity and chemical components of different ploidy P. ternata should be clarified before the superior multiploid is selected for normalized plantation of the plant.</p>

Investigation on the molecular mechanisms of anti-hepatocarcinoma herbs of traditional Chinese medicine by cell cycle microarray / 中国中药杂志

<p><b>OBJECTIVE</b>To design DNA microarray and investigate the molecular anti-tumor mechanism of herbs of traditional Chinese medicine.</p><p><b>METHOD</b>cDNA microarrays consisting of 56 probes representing 24 human cell cycle genes were constructed, Four anti-hepatocarcinoma herbs including Radix Linderae, Hebra Artemisiae Annuae, Radix Amebiae, Radix Astragli, were chosen. Effects of herbs on SMMC-7721 cell cycle were observed by flow cytometry assay. Effects of herbs on cell cycle gene expression in SMMC-7721 cells were analyzed by comparing hybridization of Dig-Labeled cDNAs from herb-treated cells and cDNAs from untreated cells.</p><p><b>RESULT</b>Expressions of cell cycle geneswere changed in different degrees after herbs treated. Some genes were down-regulated and some genes were up-regulated. The changes in gene expression agreed with the results of flow cytometry assay.</p><p><b>CONCLUSION</b>The results suggest that these herbs may have effects on cell cycle and DNA damage checkpoint genes which may be the mechanism of the herbs, and DNA microarray can be used to investigate the biological function of extracts of traditional Chinese medicine.</p>