Relationship between peroxidase activity and organogenesis in Panax ginseng calluses

The changes of redox status during culture and their effect on organogenesis were investigated in ginseng callus cultures. Three kinds of Panax ginseng calluses (non-organogenic calluses, root-forming and bud-forming calli) 21 were obtained from each of the three examined auxins (2,4-D, IBA and NAA) at 2 mg l^–1 (9.05 M 2,4-D; 9.84 M IBA; 10.74 M NAA) concentration and 0.1 mg l^–1 (0.46 M) kinetin over 5 weeks. Peroxidase in the soluble fraction, which indicates oxidative status and shows a correlation with differentiation, was higher in bud-forming calluses cultured in the three types of auxins. On the other hand, reducing capacity (overall reducing capacity of glutathione, ascorbic acid, tocoferol, carotenoids and phenol) which indicates reductive status, was higher when these calluses grew on media containing 2,4-D but specially so in the case of non-organogenic calluses. With the three types of auxin used, the reducing capacity was always higher in non-organogenic calluses and lower in calluses with more organogenic capacity. It seems that organogenesis of calluses is conditioned by a high peroxidase activity in soluble fraction (equal to or more than 0.8 A430/mg protein per min) and therefore a low reducing capacity (less than 0.3 A760/g DW). On the other hand 2,4-D promotes proliferation whereas NAA promotes morphogenesis.     

Somatic embryogenesis of Panax ginseng in liquid cultures: a role for polyamines and their metabolic pathways

A callus with embryogenic capacity was generated fromroot sections of Panax ginseng and used as aninoculum source for embryogenic liquid cultures in athree-step process: – a suspension culture of cellaggregates in the presence of an auxin/cytokininmixture, – an induction medium containing auxin only(for 5 to 30 days), – a regeneration medium containingcytokinin only (for one month). Up to 25 embryos wererecovered per 2.5 g of aggregates in these conditions.Incorporation of polyamines or their precursorsarginine and ornithine into either the induction orregeneration media increased the number of embryosproduced by up to 4 times. Inhibitors of bothbiosynthesis and biodegradation of polyamines reducedthe number of embryos. These results support earlierfindings of the role of polyamines in the process ofsomatic embryogenesis. The success of these liquidcultures opens up the possibility of producing somaticembryos of Panax ginseng in bioreactors.     

Physiological and chemical characteristics of field-and mountain-cultivated ginseng roots

Demand is increasing for mountain-cultivatedPanax ginseng (MCG) because its quality is considered superior to that of field-cultivated ginseng (FCG). However, MCG grows very slowly, and the factors that might affect this are unknown. In addition, little information is available about the physiological characteristics of its roots. Here, we investigated local soil environments and compared the histological and chemical properties of MCG and FCG roots. Average diameters, lengths, and fresh weights were much smaller in the former. Photosynthesis rates and root cambial activity also were reduced in the MCG tissues. Our analysis of soil from the mountain site revealed an extremely low phosphorus content, although those samples were richer in total nitrogen and organic matter than were the field soils. MCG roots also contained higher amounts of ginsenosides, and total accumulations increased with age. Moreover, ginsenoside Rh2, a red ginseng-specific compound, accumulated in the MCG roots but not in those from FCG plants. Interestingly, numerous calcium oxalate crystals were found in MCG roots, particularly in their rhizomes (i.e., short stems). Therefore, we can conclude from these results that low levels of the essential mineral phosphorus in mountain soils are a critical factor that retards the growth of mountain ginseng. Likewise, the high accumulation of calcium oxalate crystals in MCG roots might be an adaptation mechanism for survival in such a harsh local environment.     

Traits of Panax ginseng hairy roots after cold storage and cryopreservation

Summary Panax ginseng hairy root cultures were established by infecting petiole segments with Agrobacterium rhizogenes strain 15834. Hairy root segments including root tips placed onto phytohormone-free 1/2 Murashige and Skoog solid medium and stored at 4 °C in the dark for 4 months, resumed elongation when the temperature was raised to 25 °C in the dark. For cryopreservation, a vitrification method was applied. Root tips precultured with 0.1 mg/l 2,4-D for 3 days and dehydrated with PVS2 solution for 8 minutes prior to immersion into liquid nitrogen had a survival rate of 60 % and could regenerate. The hairy roots regenerated from cryopreserved root tips grew well and showed the same ginsenoside productivity and patterns as those of the control hairy roots cultured continuously at 25 °C. The conservation of T-DNAs in the regenerated hairy roots was proved by PCR analysis.Abbreviations 1/2 MS a half strength Murashige and Skoog (1962) - B5 Gamborg B5 (Gamborg et al. 1968) - WP woody plant (Lloyd and McCown 1980) - RC root culture (Thomas and Davey 1982) - RCI root culture medium containing 100 mg/l myoinositol - HF phytohormone-free - IAA indole-3-acetic acid - IBA indole-3-butyric acid - 2,4-D 2,4-dichlorophenoxyacetic acid - TIBA 2,3,5-triiodobenzoic acid - PCR polymerase chain reaction - PVS2 plant vitrification solution 2 (Sakai et al., 1990) - FDA fluorecein diacetate     

Pilot-scale culture of adventitious roots of ginseng in a bioreactor system

A pilot-scale culture of multiple adventitious roots of ginseng was established using a balloon-type bubble bioreactor. Adventitious roots (2 cm) induced from callus were cultured in plastic Petri dishes having 20 ml of solid Schenk and Hildebrandt (1972) medium containing 3% sucrose, 0.15% gelrite, and 24.6 μM indole-3-butric acid. An average of 29 secondary multiple adventitious roots were produced after 4 weeks of culture. These secondary roots were elongated on the same medium, reaching a length of 5 cm after 6 weeks of culture. A time course study revealed that maximum yields in 5-l and 20-l bioreactors were approximately 500 g and 2.2 kg at day 42 with 60 g and 240 g inoculations, respectively. Cutting twice during the culture increased the total amount of biomass produced. The root biomass in a 20-l balloon-type bubble bioreactor was 2.8 kg at harvest with 240 g of inoculum after 8 weeks of culture. The total saponin content obtained from small-scale and pilot-scale balloon type bubble bioreactors was around 1% based on dry weight. Inoculation of 500 g fresh weight of multiple adventitious roots into a 500 l balloon-type bubble bioreactor with cutting at 4 and 6 weeks after inoculation produced approximately 74.8 kg of multiple roots. The ginsengnoside profiles of these multiple adventitious roots were similar to profiles of field-grown ginseng roots when analyzed by HPLC. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effect of plumule and radicle on somatic embryogenesis in the cultures of ginseng zygotic embryos

Immature zygotic embryos of ginseng produced somatic embryos on MS medium without growth regulators. However, in the culture of mature zygotic embryos, excision of the embryo was required for somatic embryo induction. Somatic embryos formed only on excised cotyledons without an embryo axis or on excised embryos without the plumule and radicle of the axis. This observation suggests that the axis tip of the embryo might suppress somatic embryo production although the cotyledon tissues have predetermined embryogenic competency. To clarify the role of the embryo axis on somatic embryo formation, excised plumules or radicles were placed in direct contact with the basal cut-ends of cotyledons. The adhesion of plumules or radicles highly suppressed somatic embryo formation from cotyledon explants. When an agar block containing exudate from excised plumules or radicles was placed in contact with the cut end of the cotyledon, a similar inhibition was observed. These results suggest that embryogenic competence is suppressed by endogenous inhibitors present in the axis tip of the zygotic embryo.     

Plant regeneration through somatic embryogenesis in root-derived callus of ginseng (Panax ginseng C. A. Meyer)

Summary Callus culture was initiated from expiants of mature root tissues of ginseng (Panax ginseng C.A. Meyer) on MS medium enriched with 2,4-D. The ageing callus produced numerous embryoids in this medium. Reculture of these embryoids in media (1/2 MS or B5) supplemented with benzyladenine and gibberellic acid resulted in profuse plantlet regeneration.     

The Agrobacterium rhizogenes rolC-gene-induced somatic embryogenesis and shoot organogenesis in Panax ginseng transformed calluses

Expression of the Agrobacterium rhizogenes rolC gene in Panax ginseng callus cells results in formation of tumors that are capable to form roots. The selection of non-root forming tumor clusters yielded the embryogenic 2c3 callus line, which formed somatic embryos and shoots independently of external growth factors. Although the 2c3 somatic embryos developed through a typical embryogenesis process, they terminated prematurely and repeatedly formed adventitious shoot meristems and embryo-like structures. A part of the shoots and somatic embryos formed enlarged and fasciated meristems. This is the first indication of the rolC gene embryogenic effect and, to our knowledge, the first indication that a single gene of non-plant origin can induce somatic embryogenesis in plants.     

三七环二肽成分和人参内酰胺成分

From the roots of Panax notoginseng fourteen cyclodipeptides 1-14 were isolated including one new compound (1),seven new natural compounds (4-10) and six known compounds (2-3,11-14) together with one known other compound 15.The chemical structure of 1 was elucidated as cyclo-(Leu-Thr) based on spectral methods.From the roots of Panax ginseng five known lactams (16-20) includingpyrng lutamic acid were isolated together with butyric diacid,daucosterol and sucrose.The primary binactivity test showed that pyroglutamic acid and its n-butyl derivative have weak Ca^2 antagonistic activity.     

Calcium-dependent mechanism of somatic embryogenesis in Panax ginseng cell cultures expressing the rolC oncogene

The Panax ginseng 2c3 embryogenic cell culture was earlier obtained by callus cell transformation with Agrobacterium rhizogenes rolC. Calcium channel blockers (LaCl₃, verapamil, and niflumic acid) reduced the production of somatic embryos in the 2c3 culture, implicating the Ca²⁺ signaling system in plant somatic embryogenesis. The protein kinase inhibitors W7 and H7 also decreased the yield of somatic embryos in the 2c3 culture. The total CDPK expression in the 2c3 culture was 1.2-to 1.5-fold lower than in a control callus culture as a result of a silencing of the genes belonging to the PgCDPK1 (PgCDPK1a and PgCDPK1b) and PgCDPK3 (PgCDPK3a) subfamilies. Expression of the PgCDPK2 subfamily genes (PgCDPK2b and PgCDPK2d) was increased. It was assumed that some genes of the PgCDPK1, PgCDPK2, and PgCDPK3 subfamilies were responsible for generation of embryogenic cells in the 2c3 culture. For the first time, rolC expression and embryogenesis were associated with changes in the expression of certain CDPK genes.     

RAPD analysis of genetic variation between a group of rose cultivars and selected wild rose species

The genetic variability based on random-amplified polymorphic DNA markers was analysed among 10 cultivated rose varieties and 9 wild species from three different series of the genus Rosa. Using 13 different RAPD primers, 104 polymorphic DNA fragments with a high potential to differentiate rose genotypes could be produced. A dendrogram displaying the relative genetic similarities among the genotypes shows the existence of large genetic diversity among the cultivated roses as compared to the wild species. Furthermore, the main clusters found here are in agreement with known pedigrees and the classical taxonomy. However, the relationships between cultivated roses as inferred by RAPD markers do not correlate with the classical rose classification system. From the present data it is concluded that cultivated roses display a high level of genetic variability despite the fact that single morphological and physiological characters may be less polymorphic within rose groups. This contrasts with the widely accepted opinion of a lack of genetic variability in roses. This is also in accordance with the reported history of rose breeding which makes it highly probable that rose genomes comprise mosaics of different species genomes. As a consequence, it may be possible to utilize the high genetic variability of all genetic traits not under actual selection by breeders for future breeding programmes.     

Identification and differentiation of Panax species using ELISA, RAPD and eastern blotting

Immunochemical and genetic methods have been developed in order to distinguish Panax spp. With the aim of establishing immunochemical methods, two hybridomas (3H4 and 5H8), each secreting a monoclonal antibody (MAb) against proteins of Panax ginseng, were prepared by fusing splenocytes immunized with two kinds of ginseng water-soluble fractions and a hypoxanthine-thymidine-aminopterin-sensitive mouse myeloma cell line, P3-X63-Ag8-U1. MAb 3H4 cross-reacted with four Panax spp., whereas the MAb 5H8 cross-reacted with P. ginseng in the enzyme-linked immunosorbent assay (ELISA). ELISA and western blotting methods using a ginseng water-soluble fraction as the solid-phase antigen were developed for the unambiguous authentication of P. ginseng. A combination of random amplified polymorphic DNA (RAPD) and eastern blotting analyses using anti-ginsenoside Rb1 and Rgl monoclonal antibodies was used for the identification of P. notoginseng, P. quinquefolius and P. japonicus. RAPD can be used to differentiate the species of Panax from each other. An important parameter used for differentiating P. notoginseng is the absence of ginsenoside Rc in the extract of P. notoginseng with eastern blotting. The combination of these methods enabled a reliable identification of Panax spp.     

Novel dammarane-type sapogenins from Panax ginseng berry and their biological activities

Three new dammarane-type sapogenins (1, 3, and 5) together with two known ones (2 and 4) were isolated from the total hydrolyzed saponins extracted from Panax ginseng berry. Their structures were elucidated using a combination of 1D and 2D ¹H and ¹³C NMR spectra and mass spectroscopy as 20(R)-25-methoxyl-dammarane-3β,12β,20-triol (1), 20(R)-25-methoxyl-dammarane-3β,6α,12β,20-tetrol (2), 20(R)-20-methoxyl-dammarane-3β,12β,25-triol (3), 20(R)-20,25-dimethoxyl-dammarane-3β,12β-diol (4), and (12R,20S,24S)-20,24-; 12,24-diepoxy-dammarane-3β-ol (5). Their antitumor activities were evaluated in six human cancer cell lines. The novel compounds 1 and 3 showed significant cytotoxic activity against the six cell lines. The IC₅₀ values of 3 against HepG2, Colon205, and HL-60 were the lowest (8.78, 8.64, and 3.98 μM, respectively). Compounds 1 and 20(S)-25-OCH₃-PPD, which are a pair of configuration isomers, showed a 10- to 100-fold greater growth inhibition than ginsenoside-Rg₃ (an anti-cancer clinical agent in China). The data presented here may be useful for the development of novel anti-cancer agents.     

Methyl jasmonate and salicylic acid elicitation induces ginsenosides accumulation, enzymatic and non-enzymatic antioxidant in suspension culture Panax ginseng roots in bioreactors

The effects of methyl jasmonate (MJ) and salicylic acid (SA) on changes of the activities of major antioxidant enzymes, superoxide anion accumulation (O₂ ⁻), ascorbate, total glutathione (TG), malondialdehyde (MDA) content and ginsenoside accumulation were investigated in ginseng roots (Panax ginseng L.) in 4 l (working volume) air lift bioreactors. Single treatment of 200 μM MJ and SA to P. ginseng roots enhanced ginsenoside accumulation compared to the control and harvested 3, 5, 7 and 9 days after treatment. MJ and SA treatment induced an oxidative stress in P. ginseng roots, as shown by an increase in lipid peroxidation due to rise in O₂ ⁻ accumulation. Activity of superoxide dismutase (SOD) was inhibited in MJ-treated roots, while the activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), SOD, guaiacol peroxidase (G-POD), glutathione peroxidase (GPx) and glutathione reductase (GR) were induced in SA-treated roots. A strong decrease in the activity of catalase (CAT) was obtained in both MJ- and SA-treated roots. Activities of ascorbate peroxidase (APX) and glutathione S transferase (GST) were higher in MJ than SA while the contents of reduced ascorbate (ASC), redox state (ASC/(ASC+DHA)) and TG were higher in SA- than MJ-treated roots while oxidized ascorbate (DHA) decreased in both cases. The result of these analyses suggests that roots are better protected against the O₂ ⁻ stress, thus mitigating MJ and SA stress. The information obtained in this work is useful for efficient large-scale production of ginsenoside by plant-root cultures.     

Micropropagation ofPanax notoginseng by somatic embryogenesis and RAPD analysis of regenerated plantlets

Somatic embryogenesis was induced in callus tissues derived from young flower buds ofPanax notoginseng via callus within 18 weeks of culture. The mature somatic embryos were germinated on half-strength Murashige and Skoog's (MS) medium supplemented with gibberellic acid A₃(GA) and 6-benzyladenine (BA). The most suitable medium for optimal root formation proved to be MS medium supplemented with 1-naphthaleneacetic acid (NAA). Total DNA was extracted from the leaves of the regenerated plantlets ofP. notoginseng. Analysis of random-amplified polymorphic DNA (RAPD) using 21 arbitrary oligonucleotide 10-mers, showed the genetic homogeneity ofP. notoginseng. The amplification products were monomorphic for all of the plantlets ofP. notoginseng regenerated by embryogenesis, suggesting that somatic embryogenesis can be used for clonal micropropagation of this plant.     

Enhanced Ginsenoside Productivity by Combination of Ethephon and Methyl Jasmoante in Ginseng (Panax ginseng C.A. Meyer) Adventitious Root Cultures

Ethephon at 50 μM enhanced both root growth and ginsenoside accumulation in ginseng (Panax ginseng C.A. Meyer) adventitious root cultures, but at 100 μM it inhibited only ginsenoside accumulation. Ginsenoside productivity with 50 μM ethephon was the highest at 1.7 mg l⁻¹ d⁻¹ after 8 days of elicitation. However, elicitation with 50 μM ethephon and 100 μM methyl jasmonate (MJ) improved productivity (6.3 mg l⁻¹ d⁻¹) whereas elicitation with 100 μM MJ alone gave only 2.9 mg l⁻¹ d⁻¹.     

Development and characterization of new microsatellite markers for ginseng (<Emphasis Type="Italic">Panax ginseng</Emphasis> C. A. Meyer)

Panax ginseng C.A. Meyer, commonly known as Korean or Asian ginseng, is a perennial herb native to Korea and China. Its roots are highly prized for several medicinal properties. The present study describes development and characterization of twenty-two polymorphic microsatellite markers for this species. A total of 99 alleles were detected with an average of 4.5 alleles per locus across 20 accessions. Values for observed (H _O ) and expected (H _E ) heterozygosities ranged from 0.05 to 1.00 and from 0.18 to 0.73, respectively. Eleven loci deviated from Hardy–Weinberg equilibrium (P < 0.001). Significant (P < 0.05) heterozygote deficiency was observed at 13 loci. Exact test for linkage disequilibrium showed significant values (P < 0.05) between 12 pairs of loci. These microsatellite markers provide powerful tools for understanding population and conservation genetics of this species and also for genetic differentiation and authentication of different Panax species being used in commercial ginseng products.     

Cryopreservation of Panax ginseng cells

The impacts of cryoprotectants (CP) and cell status during the growth cycle on Panax ginseng cell viability during cryopreservation were investigated. The ginseng cells used had a 5–7 times proliferation rate (compared with inoculum) in 2–3 weeks and were subcultured at 2- and 4-week intervals in liquid and on solid media, respectively. After testing various CP solutions of glycerol, dimethylsulphoxide, ethylene glycol and sucrose, a combination of 10% (v/v) glycerol and 4% (w/v) sucrose was selected for its least cytotoxicity and highest cell viability after thawing. With this CP solution, cells throughout the growth cycle exhibited a ‘U’-shaped fluctuation of post-thaw cell viability. The highest viability (86.5%) occurred during the lag phase from cells already maintained in suspension culture and then in the late exponential phase (61.7%); the lowest level of 15.4% was in the mid-exponential phase. Callus freshly transferred to liquid medium showed a less obvious fluctuation pattern. The recovered cells were brown-to-reddish at first and gradually returned to a light yellow colour after several subcultures. Received: 1 October 1998 / Revision received: 6 January 2000 / Accepted: 11 January 2000     

Isolation of a ribonuclease from sanchi ginseng (Panax pseudoginseng) flowers distinct from other ginseng ribonucleases

A single-chained ribonuclease was isolated from the aqueous extract of sanchi ginseng (Panax pseudoginseng) flowers. It exhibited a molecular mass of 23 kDa, an N-terminal sequence with some similarity to other enzymes involved in RNA metabolism but different from known ribonucleases, and considerably higher activity toward poly U than poly C and only slight activity toward poly A and poly G. The purification protocol entailed ion exchange chromatography on diethylaminoethyl (DEAE)-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on carboxymethyl (CM)-cellulose, and gel filtration on Superdex 75. The ribonuclease was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel and CM-cellulose. Maximal activity of the ribonuclease was attained at pH 7. On either side of this pH the enzyme activity underwent a drastic decline. The enzyme activity was at its highest at 50 degrees C and dropped to about 20% of the maximal activity when the temperature was decreased to 20 degrees C or elevated to 80 degrees C. The characteristics of sanchi ginseng flower ribonuclease were different from those of the ribonucleases previously purified from sanchi ginseng and Chinese ginseng roots including ribonuclease from Chinese ginseng flowers which are morphologically very similar to sanchi ginseng flowers.