[Screening and verification of proteins of Salvia miltiorrhiza polyphenol oxidase interaction].

Polyphenol oxidase(PPO) is an important antioxidant enzyme in plants. It has the functions of scavenging active oxygen and synthesizing phenols, lignin, and plant protection factors, and can enhance the plant's resistance to stress and resistance to pests and diseases. Our previous research found that Salvia miltiorrhiza PPO gene can positively regulate salvianolic acid B synthesis. In order to further explore the mechanism, a pGBKT7-PPO bait vector was constructed using the cloned S. miltiorrhiza polyphenol oxidase gene(SmPPO, GenBank accession number: KF712274.1), and verified that it had no self-activation and no toxicity. The titer of S. miltiorrhiza cDNA library constructed by our laboratory was 4.75 × 107 cfu·mL~(-1), which met the requirements for library construction. Through yeast two-hybrid test, 22 proteins that could interact with SmPPO were screened. Only yeast PAL1 and TAT interacted with SmPPO through yeast co-transformation verification. Further verification was performed by bimolecular fluorescence complementary detection(BiFC). Only TAT and SmPPO interacted, so it meant that TAT and SmPPO interacted. TAT and SmPPO were truncated according to the domain, respectively. The first 126 amino acids of SmPPO and tyrosine amino transferase(TAT) were obtained to interact on the cell membrane and chloroplast. SmPPO was obtained by subcellular localization test, which was mainly loca-lized on the nucleus and cell membrane; TAT was localized on the cell membrane. Real-time quantitative PCR results showed that the SmPPO gene was mainly expressed in roots and stems; the TAT gene was expressed in roots, and the expression level in stems and flowers was low. This article lays a solid foundation for the in-depth study of the molecular mechanism of the interaction of S. miltiorrhiza SmPPO and TAT to regulate the synthesis of phenolic substances.

Three exopolysaccharides from the liquid fermentation of Polyporus umbellatus and their bioactivities.

The exopolysaccharides were extracted and separated from the broth of the liquid fermentation of P. umbellatus, and the antioxidant activities and other relative bioactivities were investigated, aiming to find clues for a wider use in the future. Three novel exopolysaccharides of PPS1, PPS2 and PPS3 with molecular weight of 3.7×104-6.9×104Da were obtained. Monosaccharide analysis showed that they were mainly composed of mannose, along with galactose and glucose with different molar ratio, and their structural features were also investigated by FT-IR, NMR and SEM. The antioxidant activity assay in vitro showed these exopolysaccharides exhibited a significant scavenging effect on DPPH· and other free radicals in a dose-dependent manner. Significantly, the stimulate nitric oxide production and phagocytic activity implied that the polysaccharides could enhance the immunity of RAW 264.7 macrophages. Other assays revealed that they have obvious cellular aging delaying activity and the DNA damage protecting activity. In conclusion, these three exopolysaccharides might have potential applications in the fields of pharmaceuticals, cosmetics, and food products.

[Screening of different AFLP fragments between near-isogenic lines of male sterile and fertile Salvia miltiorrhiza and their comparison analysis].

There is distinctive advantage of using male sterile lines to breed new cultivar and produce hybrids, when compared with general breeding method on yield and quality. In our previous work, near-isogenic lines (NILs) of male sterile and fertile Salvia miltiorrhiza have been obtained through continuous hybridization in many years. In this investigation, 378 primer combination were screened by using AFLP and BSA technique, in which 26 markers amplified from seven primers were found to tightly link to male sterile gene. Based on these markers, two linkage genetic maps were constructed. A 2 027,2 028 bp fragment was amplifed from NILs of fertile and sterile S. miltiorrhiza, respectively, using genome walking technique and previous E11/M4-208 marker as template. Four base mutations were found in intron when comparing both fragments. Among all different markers between NILs of male sterile and fertile S. miltiorrhiza, four was found to have 100% identities to chromosome 1, 3 and 5 of Arabidopsis, namely, E01/M09-418, E05/M13-308, E05/M04-750 and E01/M01-204. The E01/M09-418 marker was very close to male sterile gene of S. miltiorrhiza with distance of 2.1 cM, which also had 100% identities to male sterile gene MS2 in Arabidopsis. Both were distributed in chromosome 3 of Arabidopsis. The 2 028 bp fragment also had 100% identities to MS2 gene. Another E05/M04-750 marker that had 100% identities to chromosome 5 of Arabidopsis was found to have high identities to POP085-M05 gene of poplars and low affinity calcium antiporter CAX2 of Arabidopsis with very low E-value. The constructed genetic map and differential fragments with potential functions found in this study provide a solid foundation to lock male sterile genes in S. miltiorrhiza genome and to discover their functions.

Roles of reactive oxygen species in methyl jasmonate and nitric oxide-induced tanshinone production in Salvia miltiorrhiza hairy roots.

Salvia miltiorrhiza is one of the most popular traditional Chinese medicinal plants for treatment of coronary heart disease. Tanshinones are the main biological active compounds in S. miltiorrhiza. In this study, effects of exogenous methyl jasmonate (MJ) and nitric oxide (NO) on tanshinone production in S. miltiorrhiza hairy roots were investigated and the roles of reactive oxygen species (ROS) in MJ and NO-induced tanshinone production were elucidated further. The results showed that contents of four tanshinone compounds were significantly increased by 100 µM MJ when compared to the control. Application of 100 µM sodium nitroprusside (SNP), a donor of NO, also resulted in a significant increase of tanshinone production. Expression of two key genes encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) and 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) was up-regulated by MJ and SNP. Generations of O(2)(-) and H(2)O(2) were triggered by MJ, but not by SNP. The increase of tanshinone production and up-regulation of HMGR and DXR expression induced by MJ were significantly inhibited by ROS scavengers, superoxide dismutase (SOD) and catalase (CAT). However, neither SOD nor CAT was able to suppress the SNP-induced increase of tanshinone production and expression of HMGR and DXR gene. In conclusion, tanshinone production was significantly stimulated by MJ and SNP. Of four tanshinone compounds, cryptotanshinone accumulation was most affected by MJ elicitation, while cryptotanshinone and tanshinone IIA accumulation was more affected by SNP elicitation. ROS mediated MJ-induced tanshinone production, but SNP-induced tanshinone production was ROS independent.

Forced running enhances neurogenesis in the hippocampal dentate gyrus of adult rats and improves learning ability.

To investigate the effect of forced running in motor-driven wheel on neurogenesis in the hippocampal dentate gyrus (DG) of adult rats, 5-bromo-2-deoxyuridine (BrdU), a thymidine analog was applied to mark cell proliferation. Neuroepthelial stem cell protein (nestin) expression was used to identify neural stem/precursor cells. The BrdU- and nestin-positive cells were examined by immunohistochemical technique. The ability of learning was evaluated by Y-maze test to explore the functional role of the newborn cells in the DG after forced running. It was found that the number of BrdU- and nestin-positive cells in the DG in running groups was significantly increased compared to that in the control group (P<0.05). The effect of forced running on neurogenesis was intensity-dependent. In addition, an improvement of learning ability in Y-maze test was observed after forced running. These findings suggest that forced running in motor-driven wheel could enhance neurogenesis in the hippocampal DG of adult rats and improve learning ability.

Effects of exercise on neurogenesis in the dentate gyrus and ability of learning and memory after hippocampus lesion in adult rats.

Objective To explore the effects of exercise on dentate gyrus (DG) neurogenesis and the ability of learning and memory in hippocampus-lesioned adult rats. Methods Hippocampus lesion was produced by intrahippocampal microinjection of kainic acid (KA). Bromodeoxyuridine (BrdU) was used to label dividing cells. Y maze test was used to evaluate the ability of learning and memory. Exercise was conducted in the form of forced running in a motor-driven running wheel. The speed of wheel revolution was regulated at 3 kinds of intensity: lightly running, moderately running, or heavily running. Results Hippocampus lesion could increase the number of BrdU-labeled DG cells, moderately running after lesion could further enhance the number of BrdU-labeled cells and decrease the error number (EN) in Y maze test, while neither lightly running, nor heavily running had such effects. There was a negative correlation between the number of DG BrdU-labeled cells and the EN in the Y maze test after running. Conclusion Moderate exercise could enhance the DG neurogenesis and ameliorate the ability of learning and memory in hippocampus-lesioned rats.