Recent advances on ginseng research in China

Ginseng, Panax ginseng C.A. Meyer, is a well-known Chinese traditional medicine. There have been more than 300 original papers in Chinese and in English during the last 10 years in China. This review paper summarizes some achievements from some of these published papers. Twenty-eight ginsenosides and some minor constituents were extracted and isolated from the root, root-stock, stems, leaves, flowers and flower-buds of ginseng. The chemical analysis demonstrated that the content of ginsenosides is related to the source, part and growth years of ginseng. The drug has a wide range of pharmacological and therapeutical actions, it acts on the central nervous system, cardiovascular system and endocrine secretion, promotes immune function and metabolism, possesses biomodulation action, anti-stress and anti-ageing activities, and so on. Many preparations of ginseng have been officially approved for clinical application in China. Clinical evaluation has shown that these preparations play a special role in medicinal use.

Activation of caspase-3 protease via a Bcl-2-insensitive pathway during the process of ginsenoside Rh2-induced apoptosis

We have demonstrated that ginsenoside Rh2 (G-Rh2), a ginseng saponin with a dammarane skeleton, induces apoptosis of human hepatoma SK-HEP-1 cells as evidenced by analyses of DNA fragmentation, flow cytometry and changes in cell morphology. Ac-YVAD-CMK or Ac-DEVD-CHO effectively prevented G-Rh2-induced DNA fragmentation, indicating the involvement of caspase-like proteases in the process of apoptosis. In addition, G-Rh2 induced the processing of caspase-3 to an active form, p17. In stable Bcl-2 transfectants, G-Rh2 also induced DNA fragmentation, while staurosporine-induced DNA fragmentation was totally blocked. As it did in wild-type cells, G-Rh2 induced the proteolytic activation of caspase-3 protease and subsequent cleavage of PARP in the bcl-2 transfectants. In summary, G-Rh2 contains an apoptotic inducing activity in SK-HEP-1 cells which functions via Bcl-2-insensitive activation of caspase-3, followed by proteolytic cleavage of PARP.

Lanosterol Synthase in Dicotyledonous Plants

Sterols are important as structural components of plasma membranes and precursors of steroidal hormones in both animals and plants. Plant sterols show a wide structural variety and significant structural differences from those of animals. To elucidate the origin of structural diversity in plant sterols, their biosynthesis has been extensively studied [Benveniste (2004) Annu. Rev. Plant. Biol. 55: 429, Schaller (2004) Plant Physiol. Biochem. 42: 465]. The differences in the biosynthesis of sterols between plants and animals begin at the step of cyclization of 2,3-oxidosqualene, which is cyclized to lanosterol in animals and to cycloartenol in plants. However, here we show that plants also have the ability to synthesize lanosterol directly from 2,3-oxidosqualene, which may lead to a new pathway to plant sterols. The Arabidopsis gene At3g45130, designated LAS1, encodes a functional lanosterol synthase in plants. A phylogenetic tree showed that LAS1 belongs to the previously uncharacterized branch of oxidosqualene cyclases, which differs from the cycloartenol synthase branch. Panax PNZ on the same branch was also shown to be a lanosterol synthase in a yeast heterologous expression system. The higher diversity of plant sterols may require two biosynthetic routes in steroidal backbone formation.

Discovery of markers for discriminating the age of cultivated ginseng by using UHPLC-QTOF/MS coupled with OPLS-DA

BACKGROUND

Ginseng (Ginseng Radix et Rhizoma, Panax ginseng C.A. Meyer) is gaining more publicity in modern society due to its health benefit and huge value in market. In the practice of grading and pricing of ginseng, the age is one of the major factor influencing the price and grade of ginseng. Therefore, the age discrimination is an important task for the quality control of ginseng. However, the traditional morphological methods are too subjective to be reproductive in discrimination.

PURPOSE

To establish a method that can discriminate the ginseng samples with different cultivation years.

STUDY DESIGN

To analyze the correlation between chemical compositions and cultivation years of cultivated ginseng samples of different age and thus discover potential quality marker (Q-marker) for discriminating the age of cultivated ginseng.

METHODS

In the present study, the ultra-high performance liquid chromatography coupled with the quadrupole-time of flight mass spectrometry (UHPLC-QTOF/MS) were utilized for the age discrimination and marker discovery. A statistical data processing procedure was established to screen markers and reduce the false positive rate.

RESULTS

The results showed that the ginseng samples from 2- to 6-year-old could be well separated in the orthogonal projections on the latent structure - discrimination analysis (OPLS-DA) using the markers screened by the established statistical procedure, which could reduce approximately 20% of the insignificant markers and false positive discoveries. Ultimately, more than 50 compounds contributing to the age discrimination were identified including one new compound (malonylginsenoside). One negative marker (1038.4825@8.98) was discovered for the 2-year-old ginseng, and an equation was established to effectively predict the age of 3- to 6-year-old of ginseng.

CONCLUSION

The constructed method can discriminate the ginseng samples with different cultivation years and is a complement to the traditional discrimination method of ginseng age.

Pharmacological actions of "kyushin," a drug containing toad venom: cardiotonic and arrhythmogenic effects, and excitatory effect on respiration

The cardiotonic and arrhythmogenic effects, and the excitatory effect on respiration of "Kyushin," a drug containing toad venom, were studied in comparison with those of digoxin. In anesthetized rabbits, the maximum rate of rise of left ventricular systolic pressure (max dP/dt) was measured as an index of cardiotonic effect, and the respiratory flow was measured as an index of respiratory function. Intraduodenal (i.d.) administration of 80 mg/kg "Kyushin" produced a cardiotonic effect and an excitatory effect on respiration, but i.d. administration of 16 mg/kg digoxin produced only a cardiotonic effect, and conversely inhibited respiration. In anesthetized open-chest guinea pigs, myocardial contractile force was measured as an index of cardiotonic effect and the arrhythmogenic effect was evaluated from the appearance of arrhythmic myocardial contraction. By i.d. administration of a 20% ethanol suspension or solution, "Kyushin" and digoxin showed a cardiotonic activity with doses higher than 40 mg/kg and 0.25 mg/kg, respectively. The arrhythmogenic doses of "Kyushin" and digoxin by i.d. administration were 2560 mg/kg and 2 mg/kg, respectively, suggesting that the safety margin of "Kyushin" is broader than that of digoxin.

Enhanced secondary metabolite biosynthesis by elicitation in transformed plant root system: effect of abiotic elicitors

Plants generally produce secondary metabolites in nature as a defense mechanism against pathogenic and insect attack. In this study, we applied several abiotic elicitors in order to enhance growth and ginseng saponin biosynthesis in the hairy roots of Panax ginseng. Generally, elicitor treatments were found to inhibit the growth of the hairy roots, although simultaneously enhancing ginseng saponin biosynthesis. Tannic acid profoundly inhibited the hairy root growth during growth period. Also, ginseng saponin content was not significantly different from that of the control. The addition of selenium at inoculum time did not significantly affect ginseng saponin biosynthesis. However, when 0.5 mM selenium was added as an elicitor after 21 d of culture, ginseng saponin content and productivity increased to about 1.31 and 1.33 times control levels, respectively. Also, the addition of 20 microM NiSO4 resulted in an increase in ginseng saponin content and productivity, to about 1.20 and 1.23 times control levels, respectively, and also did not inhibit the growth of the roots. Sodium chloride treatment inhibited hairy root growth, except at a concentration of 0.3% (w/v). Increases in the amounts of synthesized ginseng saponin were observed at all concentrations of added sodium chloride. At 0.1% (w/v) sodium chloride, ginseng saponin content and productivity were increased to approx 1.15 and 1.13 times control values, respectively. These results suggest that processing time for the generation of ginseng saponin in a hairy root culture can be reduced via the application of an elicitor.

Yeast Extract Stimulates Ginsenoside Production in Hairy Root Cultures of American Ginseng Cultivated in Shake Flasks and Nutrient Sprinkle Bioreactors

One of the most effective strategies to enhance metabolite biosynthesis and accumulation in biotechnological systems is the use of elicitation processes. This study assesses the influence of different concentrations of yeast extract (YE) on ginsenoside biosynthesis in Panax quinquefolium (American ginseng) hairy roots cultivated in shake flasks and in a nutrient sprinkle bioreactor after 3 and 7 days of elicitation. The saponin content was determined using HPLC. The maximum yield (20 mg g⁻¹ d.w.) of the sum of six examined ginsenosides (Rb1, Rb2, Rc, Rd, Re and Rg1) in hairy roots cultivated in shake flasks was achieved after application of YE at 50 mg L⁻¹ concentration and 3 day exposure time. The ginsenoside level was 1.57 times higher than that attained in control medium. The same conditions of elicitation (3 day time of exposure and 50 mg L⁻¹ of YE) also favourably influenced the biosynthesis of studied saponins in bioreactor cultures. The total ginsenoside content was 32.25 mg g⁻¹ d.w. and was higher than that achieved in control medium and in shake flasks cultures. Obtained results indicated that yeast extract can be used to increase ginsenoside production in hairy root cultures of P. quinquefolium.

Stimulation of saponin production in Panax ginseng hairy roots by two oligosaccharides from Paris polyphylla var. yunnanensis

Two oligosaccharides, a heptasaccharide (HS) and an octasaccharide (OS), isolated from Paris polyphylla var. yunnanensis, stimulated the growth and saponin accumulation of Panax ginseng hairy roots at 5-30 mg l(-1). HS and OS at 30 mg l(-1), fed separately to hairy root cultures at 10 days post-inoculation, increased the root biomass dry weight by more than 70% to approximately 20 g l(-1) from 13 g l(-1) and the total saponin content of roots by more than 1-fold to approximately 3.5% from 1.6% (w/w). The results suggest that the two oligosaccharides may have plant growth-regulatory activity in plant tissue cultures.

Molecular Cloning and Expression Analysis of Eight PgWRKY Genes in Panax ginseng Responsive to Salt and Hormones

Despite the importance of WRKY genes in plant physiological processes, little is known about their roles in Panax ginseng C.A. Meyer. Forty-eight unigenes on this species were previously reported as WRKY transcripts using the next-generation sequencing (NGS) technology. Subsequently, one gene that encodes PgWRKY1 protein belonging to subgroup II-d was cloned and functionally characterized. In this study, eight WRKY genes from the NGS-based transcriptome sequencing dataset designated as PgWRKY2-9 have been cloned and characterized. The genes encoding WRKY proteins were assigned to WRKY Group II (one subgroup II-c, four subgroup II-d, and three subgroup II-e) based on phylogenetic analysis. The cDNAs of the cloned PgWRKYs encode putative proteins ranging from 194 to 358 amino acid residues, each of which includes one WRKYGQK sequence motif and one C₂H₂-type zinc-finger motif. Quantitative real-time PCR (qRT-PCR) analysis demonstrated that the eight analyzed PgWRKY genes were expressed at different levels in various organs including leaves, roots, adventitious roots, stems, and seeds. Importantly, the transcription responses of these PgWRKYs to methyl jasmonate (MeJA) showed that PgWRKY2, PgWRKY3, PgWRKY4, PgWRKY5, PgWRKY6, and PgWRKY7 were downregulated by MeJA treatment, while PgWRKY8 and PgWRKY9 were upregulated to varying degrees. Moreover, the PgWRKY genes increased or decreased by salicylic acid (SA), abscisic acid (ABA), and NaCl treatments. The results suggest that the PgWRKYs may be multiple stress–inducible genes responding to both salt and hormones.

Complementary herbal and alternative drugs in clinical practice

TOPIC

Complementary and alternative medicine agents (CAMs).

PURPOSE

To summarize the current empirical data about the major CAMs purporting to have psychotherapeutic value.

SOURCES OF INFORMATION

Extant literature.

CONCLUSIONS

Available evidence indicates that CAMs, while generally safe, are not risk free. While CAM use grows, nurses and other health professionals have a limited knowledge base about the action, side effects, and interactions of common CAM agents. Nurses need to increase their knowledge base about CAMs in order to help patients in decision making regarding the use of these agents to treat common psychiatric symptoms.

The effect of ginseng extract on locomotor sensitization and conditioned place preference induced by methamphetamine and cocaine in mice

Repeated i.p. injections of 2 mg/kg methamphetamine (MA) or 20 mg/kg cocaine at 48-h intervals induced reverse tolerance to their ambulation-enhancing effects (behavioral sensitization). Furthermore, the reappearance of the sensitized state was observed at the time of readministration of MA or cocaine even after a 30-day discontinuation of drug administration. A concomitant injection of ginseng extract (GE), 200 mg/kg, i.p., suppressed the development of reverse tolerance and the reappearance of sensitization to MA and cocaine. Conditioned place preference to MA (1, 2, and 4 mg/kg, i.p.) and cocaine (1, 4, 10, and 20 mg/kg, i.p.), was completely blocked by GE, 200 mg/kg, i.p. combined treatment with MA of cocaine. Meanwhile, spontaneous motor activity and place preference were not affected by GE alone. These results provide evidence that GE may be useful clinically for the prevention of adverse actions of MA and cocaine.

Synergistic effects of climate change and harvest on extinction risk of American ginseng

Over the next century, the conservation of biodiversity will depend not only on our ability to understand the effect of climate change, but also on our capacity to predict how other factors interact with climate change to influence species viability. We used American ginseng (Panax quinquefolius L.), the United States' premier wild-harvested medicinal, as a model system to ask whether the effect of harvest on extinction risk depends on changing climatic conditions. We performed stochastic projections of viability response to an increase in maximum growing-season temperature of 1°C over the next 70 years by sampling matrices from long-term demographic studies of 12 populations (representing 75 population-years of data). In simulations that included harvest and climate change, extinction risk at the median population size (N = 140) was 65%, far exceeding the additive effects of the two factors (extinction risk = 8% and 6% for harvest and climate change, respectively; quasi-extinction threshold = 20). We performed a life table response experiment (LTRE) to determine underlying causes of the effect of warming and harvest on deterministic λ (λd). Together, these factors decreased λd values primarily by reducing growth of juvenile and small adult plants to the large-adult stage, as well as decreasing stasis of the juveniles and large adults. The interaction observed in stochastic model results followed from a nonlinear increase in extinction risk as the combined impact of harvest and warming consistently reduced λ values below the demographic tipping point of λ = 1. While further research is needed to create specific recommendations, these findings indicate that ginseng harvest regulations should be revised to account for changing climate. Given the possibility of nonlinear response like that reported here, pre-emptive adaptation of management strategies may increase efficacy of biodiversity conservation by allowing behavior modification prior to precipitous population decline.

Changes in the physiological characteristics of Panax ginseng embryogenic calli and molecular mechanism of ginsenoside biosynthesis under cold stress

Short-term cold stress can induce the increased expression of key enzyme-encoding genes involved in secondary metabolite synthesis, thereby increasing secondary metabolite concentration. Cold stress is an ecologically limiting factor that strongly affects the physiological and biochemical properties of medicinal plants often resulting in changes of the secondary metabolic process. Ginsenosides are the main active ingredients in medicinal ginseng yet few studies exist on the effect of cold stress on the expression of ginsenosides or the molecular mechanism underlying its regulation. Here, we evaluated the effects of cold stress on the physiological characteristics and secondary metabolism of P. ginseng embryogenic calli. Physiological measurements and RNA-Seq analysis were used to dissect the metabolic and molecular responses of P. ginseng to cold conditions. We found that the dynamic accumulation of ginsenoside and various physiological indicators leads to homogenous adaptation to cold stress. Secondary metabolism of ginseng could be a compensation mechanism to facilitate its adaptation to cold stress. Combined with the changes in the endogenous hormone content, 9-cis-epoxycarotenoid dioxygenase (NCED), zeaxanthin epoxidase (ZEP), and short chain dehydrogenase (SDR) from the abscisic acid (ABA) synthesis pathway were identified as key mediators of this response. Thus, an appropriate degree of cold stress may promote accumulation of ginsenosides. Moreover, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR2), squalene epoxidase (SE1), squalene synthase (SS), dammarenediol synthase (DS-II), and β-alanine C-28 hydroxylase (CYP716A52v2) should be considered key mediators of the cold stress response and ginsenoside biosynthesis. During industrial production, short-term cold stress should be carried out on ginseng calli to improve the quality of its medicinal materials.

A ginseng-specific abundant protein (GSAP) located on the cell wall is involved in abiotic stress tolerance

Ginseng ESTs allowed us to identify an unknown transcript which is highly abundant in rhizomes and seeds. We called the cDNA ginseng-specific abundant protein (GSAP), and identified three homologues, GSAP1, GSAP2, and GSAP3. GSAP cDNAs encode a small polypeptide consisting of 121 or 117 amino acids, and GSAP3 shows 87.6% amino acid sequence homology with GSAP1. GSAP transcripts were detected in most plant tissues, but GSAP3 is highly expressed in seeds, and is up-regulated under stressed conditions, water deficit. GSAP3-GFP fusion protein is located in the cell wall when expressed in onion epidermis cells. The transgenic Arabidopsis seedlings which over-expressed GSAP3 grew faster than those of the wild-type plant on the medium containing 300 mM mannitol and 100 mM NaCl. GSAP3 may play a role in altering the characteristics of the cell wall to allow for more tolerance of water deficit stress under abiotic stress conditions.

Experimental test for adaptive differentiation of ginseng populations reveals complex response to temperature

BACKGROUND AND AIMS

Local climatic adaptation can influence species' response to climate change. If populations within a species are adapted to local climate, directional change away from mean climatic conditions may negatively affect fitness of populations throughout the species' range.

METHODS

Adaptive differentiation to temperature was tested for in American ginseng (Panax quinquefolius) by reciprocally transplanting individuals from two populations, originating at different elevations, among temperature treatments in a controlled growth chamber environment. Fitness-related traits were measured in order to test for a population × temperature treatment interaction, and key physiological and phenological traits were measured to explain population differences in response to temperature.

KEY RESULTS

Response to temperature treatments differed between populations, suggesting genetic differentiation of populations. However, the pattern of response of fitness-related variables generally did not suggest 'home temperature' advantage, as would be expected if populations were locally adapted to temperature alone.

CONCLUSIONS

Failure consistently to detect a 'home temperature' advantage response suggests that adaptation to temperature is complex, and environmental and biotic factors that naturally covary with temperature in the field may be critical to understanding the nature of adaptation to temperature.

Ginseng radix increases cell proliferation in dentate gyrus of rats with streptozotocin-induced diabetes

In the present study, the effect of Ginseng radix on cell proliferation in the dentate gyrus of rats with streptozotocin-induced diabetes was investigated via immunohistochemistry. Aqueous extract of Ginseng radix was shown to exert no significant effect on weight in normal rats, while it prevented weight loss in rats with streptozotocin-induced diabetes. Cell proliferation in the dentate gyrus of diabetic rats was increased by Ginseng radix treatment, but it had no effect on cell proliferation in normal rats. These results suggest that Ginseng radix may help in improve the central nervous system complications of diabetes mellitus.

Decreased Hill reaction rates and slow turnover of transitory starch in the obligate shade plant Panax quinquefolius L. (American ginseng)

To identify physiological processes that might limit photosynthesis in Panax quinquefolius L. (American ginseng) a comparison has been made with Panax ginseng C.A. Meyer (Korean ginseng), Pisum sativum L. (pea) and Spinacia oleracea L. (spinach). The quantum yield of oxygen evolution in intact leaves and isolated thylakoid membranes was found to be smaller in ginseng than in pea or spinach. However, the number of photosystem II (PSII) centers on a chlorophyll basis was found to be similar in all species. This suggests that ginseng thylakoid membranes possess relatively more inactive PSII centers than thylakoids of pea and spinach when grown under similar conditions. Unexpectedly, whole-chain electron transport from water to methyl viologen, and partial photosystem I reactions, demonstrated that electron transport rates to methyl viologen were anomalously low in P. quinquefolius and P. ginseng. Additionally, at elevated light intensities, intact leaves of P. quinquefolius were more susceptible to lipid peroxidation than pea leaves. In plants grown at a light intensity of 80 micro mol photons m(-2) s(-1) the levels of fructose and starch were higher in both ginseng species than in pea or spinach. Significantly, the level of starch in P. quinquefolius was relatively constant throughout the entire 12 h/12 h light/dark cycle and remained high after an extended dark time of 48 h. In addition, P. quinquefolius had lower activities of alpha-amylase and beta-amylase than P. ginseng, pea and Arabidopsis thaliana (L.) Heynh. The significance of the elevated levels of leaf starch in P. quinquefolius remains to be determined. However, the susceptibility of P. quinquefolius to photoinhibition may arise as a consequence of a reduced fraction of active PSII centers. This may result in the normal dissipative mechanisms in these plants becoming saturated at elevated, but moderate, light intensities.

Production of herbicide-resistant transgenic Panax ginseng through the introduction of the phosphinothricin acetyl transferase gene and successful soil transfer

Herbicide-resistant transgenic Panax ginseng plants were produced by introducing the phosphinothricin acetyl transferase (PAT) gene that confers resistance to the herbicide Basta (bialaphos) through Agrobacterium tumefaciens co-cultivation. Embryogenic callus gathered from cotyledon explants of P. ginseng were pre-treated with 0.5 M sucrose or 0.05 M MgSO(4 )before Agrobacterium infection. This pre-treatment process markedly enhanced the transient expression of the beta-glucuronidase (GUS) gene. Embryogenic callus was initially cultured on MS medium supplemented with 400 mg/l cefotaxime for 3 weeks and subsequently subcultured five times to a medium containing 25 mg/l kanamycin and 300 mg/l cefotaxime. Somatic embryos formed on the surfaces of kanamycin-resistant callus. Upon development into the cotyledonary stage, these somatic embryos were transferred to a medium containing 50 mg/l kanamycin and 5 mg/l gibberellic acid to induce germination and strong selection. Integration of the transgene into the plants was confirmed by polymerase chain reaction and Southern analyses. Transfer of the transgenic ginseng plantlets to soil was successfully accomplished via acclimatization in autoclaved perlite. Not all of the plantlets survived in soil that had not been autoclaved because of fungal infection, particularly in the region between the roots and leaves. Transgenic plants growing in soil were observed to be strongly resistant to Basta application.

Effects of "kyushin", a drug containing toad venom, on experimental congestive heart failure in rabbits

Effects of "Kyushin" (KY-2), a drug containing toad venom, on a low-output-type heart failure model produced in rabbits by protease treatment on the left ventricular anterior wall, were examined. Heart rate, aortic blood flow (AoF), left ventricular systolic pressure (LVP) and maximal rate of rise of LVP (max dP/dt) in this model were maintained at lower levels than those in normal rabbits, while left ventricular end-diastolic pressure (LVEDP) and systemic vascular resistance (SVR) were maintained at higher levels, and the mean blood pressure (MBP) was at a normal level. KY-2 was administered intraduodenally to the animal. KY-2 improved heart failure state by increasing the AoF, LVP and max dP/dt, and by decreasing the LVEDP and SVR without a significant change in MBP. These results suggest that the beneficial effects of KY-2 on this heart failure model originate from their cardiotonic activity.

Ginseng (Panax ginseng)

Genetic transformation is an attractive way to improve Panax ginseng C. A. Meyer by introducing new genetic materials and altering metabolic pathways that regulating the production of secondary compounds. In P. ginseng, production of transgenic plants via Agrobacterium tumefaciens is performed via somatic embryogenesis using cotyledon or embryogenic callus as explants. This chapter introduces the protocol of A. tumefaciens mediated-genetic transformation in P. ginseng.

Functional Characterization of BRASSINAZOLE-RESISTANT 1 in Panax Ginseng (PgBZR1) and Brassinosteroid Response during Storage Root Formation

Brassinosteroids (BRs) play crucial roles in the physiology and development of plants. In the model plant Arabidopsis, BR signaling is initiated at the level of membrane receptors, BRASSINOSTEROIDS INSENSITIVE 1 (BRI1) and BRI1-ASSOCIATED RECEPTOR KINASE 1 (BAK1) complex, thus activating the transcription factors (TFs) BRASSINAZOLE RESISTANT 1/BRI1-EMS-SUPPRESSOR 1 (BZR1/BES1) to coordinate BR responsive genes. BRASSINOSTEROIDS INSENSITIVE 2 (BIN2), glycogen synthase kinase 3 (GSK3) like-kinase, negatively regulates BZR1/BES1 transcriptional activity through phosphorylation-dependent cytosolic retention and shuttling. However, it is still unknown whether this mechanism is conserved in Panax ginseng C. A. Mayer, a member of the Araliaceae family, which is a shade-tolerant perennial root crop. Despite its pharmacological and agricultural importance, the role of BR signaling in the development of P. ginseng and characterization of BR signaling components are still elusive. In this study, by utilizing the Arabidopsisbri1 mutant, we found that ectopic expression of the gain of function form of PgBZR1 (Pgbzr1-1D) restores BR deficiency. In detail, ectopic expression of Pgbzr1-1D rescues dwarfism, defects of floral organ development, and hypocotyl elongation of bri1-5, implying the functional conservation of PgBZR1 in P. ginseng. Interestingly, brassinolide (BL) and BRs biosynthesis inhibitor treatment in two-year-old P. ginseng storage root interferes with and promotes, respectively, secondary growth in terms of xylem formation. Altogether, our results provide new insight into the functional conservation and potential diversification of BR signaling and response in P. ginseng.

[Prediction model of net photosynthetic rate of ginseng under forest based on optimized parameters support vector machine]

Using K-fold cross validation method and two support vector machine functions, four kernel functions, grid-search, genetic algorithm and particle swarm optimization, the authors constructed the support vector machine model of the best penalty parameter c and the best correlation coefficient. Using information granulation technology, the authors constructed P particle and epsilon particle about those factors affecting net photosynthetic rate, and reduced these dimensions of the determinant. P particle includes the percent of visible spectrum ingredients. Epsilon particle includes leaf temperature, scattering radiation, air temperature, and so on. It is possible to obtain the best correlation coefficient among photosynthetic effective radiation, visible spectrum and individual net photosynthetic rate by this technology. The authors constructed the training set and the forecasting set including photosynthetic effective radiation, P particle and epsilon particle. The result shows that epsilon-SVR-RBF-genetic algorithm model, nu-SVR-linear-grid-search model and nu-SVR-RBF-genetic algorithm model obtain the correlation coefficient of up to 97% about the forecasting set including photosynthetic effective radiation and P particle. The penalty parameter c of nu-SVR-linear-grid-search model is the minimum, so the model's generalization ability is the best. The authors forecasted the forecasting set including photosynthetic effective radiation, P particle and epsilon particle by the model, and the correlation coefficient is up to 96%.

[Effects of acid and alkali stress on ginsenoside content and histochemical localization of ginsenoside in adventitious root of Panax ginseng]

To investigate the effect of acid and alkali stress on ginsenoside content of Panax ginseng, adventitious roots culture in bioreactors were incubated for 30 d and pH value was adjusted. Ginsenoside content increased by reducing or raising the pH in culture medium, the muxium ginsenoside content was determined on the 5th days after acid treatment and on the 7th days after alkali treatment. The result of histochemical localization of ginsenoside revealed that the red color from light to dark were found in the adventitious root tissue, and ginsenoside mainly located in the pericycle cells where appeared the dark red color.