Panax ginseng Meyer is one of the important medicinal plants in the world, particularly in Asian countries. Ginseng encounters many stress exposure during its long cultivation period. However, the molecular mechanism of stress resistance is still poorly understood in spite of its importance. In this study, pathogenesis-related protein 6 (PR6), also called proteinase inhibitor (PI), was isolated from ginseng embryogenic callus, named PgPR6. The small size of PR6, containing an open reading frame of 219 bp encoding 72 amino acids, the typical characteristic of PR6 protein, shares the highest sequence similarity to PR6 of Theobroma cacao (69% identity). Sequence and structural analysis indicated that PgPR6 belongs to class Kunitz-type PI family. This is the first report pertaining to the identification of PR6 gene from the P. ginseng genome. The high-level expression of PgPR6 was observed in root as revealed by quantitative real-time PCR. The temporal expression analysis demonstrated that PgPR6 expression was highly up-regulated by signaling molecules, heavy metals, mechanical wounding, chilling, salt, sucrose, and mannitol stress, indicating that PgPR6 may play an important role in the molecular defense response of ginseng to a various range of environmental stresses. 相似文献
We tested desiccation and/or vitrification procedures to cryopreserve the adventitious roots of Panax ginseng, the source of commercially produced ginsenosides. When only desiccation was applied, the post-freeze survival of 3- to 4-mm
root tips was <14% regardless of the composition of the preculture medium or the explant origin. Callus formation was frequently
observed after cryopreservation. In contrast, 90% survival and 32.5% root formation efficiency were achieved after cryopreservation
when a vitrification protocol was followed. Adventitious root cultures in flasks and bioreactors were reestablished from root
tips cryopreserved by vitrification. A prolonged lag-phase and lower biomass production were recorded in post-freeze-regenerated
cultures compared with control roots that were subcultured four times in flasks. However, biomass accumulations did not differ
between control and regenerated roots at the end of the sixth subculturing period. After 40 days of culture in bioreactors,
a mean value of 12.5 g dw L−1 was recorded for post-freeze-regenerated cultures versus 9.1 g dw L−1 for the control roots. Production of triol and diol ginsenosides in our bioreactor cultures also was enhanced after cryopreservation,
by 41.0% and 89.8%, respectively. These results suggest that the vitrification method is successful for cryopreservation of
P. ginseng adventitious roots. 相似文献
A somatic embryogenesis protocol for plant regeneration of northern red oak (Quercus rubra) was established from immature cotyledon explants. Embryogenic callus cultures were induced on Murashige and Skoog medium
(MS) containing 3% sucrose, 0.24% Phytagel™, and various concentrations of 2,4-dichlorophenoxyacetic acid (2,4-d) after 4 weeks of culture in darkness. A higher response (66%) of embryogenic callus was induced on 0.45 μM 2,4-d. Higher numbers of globular- (31), heart- (17), torpedo- (12), and cotyledon-stage (8) embryos per explant were obtained
by culturing embryogenic callus on MS with 3% sucrose, 0.24% Phytagel™, and devoid of growth regulators after 8 weeks culture
in darkness. Continuous sub-culturing of embryogenic callus on medium containing 2,4-d yielded only compact callus. Desiccation of embryos for 3 days in darkness at 25 ± 2°C followed by cold storage at 4°C in
darkness for 8 weeks favored embryo germination and development of plantlets. Cotyledon-stage embryos subjected to desiccation
and chilling treatment cultured on MS with 3% sucrose, 0.24 Phytagel™, 0.44 μM 6-benzylaminopurine (BA), and 0.29 μM gibberellic
acid germinated at a higher frequency (61%) than with 0.44 μM BA alone and control cultures. Germinated plantlets developed
a shoot and root, were acclimatized successfully, and maintained in a growth room for plantlet development. 相似文献
A novel strain, DCY108T was isolated from soil of a Panax ginseng field, Yeoncheon province (38°04′N 126°57′E), Republic of Korea. Strain DCY108T is Gram-negative, non-motile, non-flagellate, rod-shaped, and aerobic. The bacterium grows optimally at 25–30 °C, pH 6.5–7.0 and 1 % NaCl. Phylogenetically, strain DCY108T is closely related to Pedobacter jejuensis JCM 18824T, Pedobacter aquatilis JCM 13454T, Pedobacter kyungheensis LMG 26577T and the type strain of the genus Pedobacter heparinus DSM 2366T. The DNA–DNA relatedness values between strain DCY108T and its close phylogenetic neighbors were below 30.0 %. The DNA G+C content of strain DCY108T was determined to be 45.1 mol%. The predominant quinone was menaquinone 7 (MK-7). The major polar lipids were identified as phosphatidylethanolamine and three unidentified aminolipids AL1, AL13 and AL17. Iso-C15:00, iso-C17:03OH and summed feature 3 (C16:1ω7c/C16:1ω6c) were identified as the major fatty acids present in strain DCY108T. The results of physiological and biochemical tests allowed strain DCY108T to be differentiated phenotypically from other recognized species belonging to the genus Pedobacter. Therefore, it is suggested that the newly isolated organism represents a novel species, for which the name Pedobacter panacis sp. nov is proposed with the type strain designated as DCY108T (=CCTCCAB 2015196T = KCTC 42748T). 相似文献
A novel strain DCY105T was isolated from soil collected from the rhizosphere of ginseng (Panax ginseng), in Gochang, Republic of Korea. Strain DCY105T is Gram-reaction-negative, white, non-motile, non-flagellate, rod-shaped and aerobic. The bacteria grow optimally at 30°C, pH 6.5–7.0 and in the absence of NaCl. Phylogenetically, strain DCY105T is most closely related to Achromobacter marplatensis LMG 26219T (96.81%). The DNA G+C content of strain DCY105T was 64.4 mol%. Ubiquinone 8 was the major respiratory quinone, and phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol were amongst the major polar lipids. C16:00, C8:03OH and iso-C17:03OH were identified as the major fatty acids present in DCY105T. The results of physiological and biochemical tests allowed strain DCY105T to be differentiated phenotypically from other recognized species belonging to the genus Achromobacter. Therefore, it is suggested that the newly isolated organism represents a novel species, for which the name Achromobacter panacis sp. nov. is proposed with the type strain designated as DCY105T (=CCTCCAB 2015193T =KCTC 42751T). 相似文献
One of the major trends within the food industry is the replacement of synthetically-derived food additives (e.g. emulsifiers) by natural alternatives. A promising approach is the utilization of saponins that have attracted attention due to their effective emulsifying properties and their natural origin from plants. Panax ginseng is well known in Asian countries for its health benefits that are mainly attributed to amphiphilic triterpene saponins, namely ginsenosides. In this study, we characterized two food-grade ginseng extracts (Finzelberg: FB; CheilJedang: CJ) regarding their chemical composition, surface activity, and effectiveness as emulsifier. Both ginseng extracts reduced the interfacial tension appreciably by up to 80%, and formed negatively charged oil-in-water emulsions at a low emulsifier-to-oil ratio. Ginseng FB formed small submicron-sized emulsions, whereas the mean particle sizes with ginseng CJ were much larger (up to 25 μm). Both ginseng extract-stabilized emulsions were stable towards a range of stresses (pH 4–9, ≤100 mM NaCl) or when stored at ≤25 °C for four weeks. However, the emulsions showed instability at highly acidic conditions (pH 2–3), during the 4-week storage at an elevated temperature (55 °C), and at high ionic strengths (≥250 mM NaCl, >10 mM CaCl2), which was mainly attributed to the reduction or screening of electrostatic repulsion. Emulsion formation and stabilization was proposed to occur via formation of a saponin or biogenic saponin-protein complex layer leading to a stronger interfacial network. In conclusion, both ginseng extracts were able to form emulsions, although ginseng FB extract showed especially remarkable emulsifying properties, similar to the highly effective Quillaja saponaria extract. The results may therefore be helpful in replacing other emulsifiers and formulating emulsion products with varying particle size ranges.
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 ∼20 g l−1 from 13 g l−1 and the total saponin content of roots by more than 1-fold to ∼3.5% from 1.6% (w/w). The results suggest that the two oligosaccharides
may have plant growth-regulatory activity in plant tissue cultures. 相似文献
It has been shown previously that the rolC gene from Agrobacterium tumefaciens gene was stably and highly expressed in 15-year-old Panax ginseng transgenic cell cultures. In the present report, we analyze in detail the nucleotide composition of the rolC and nptII (neomycin phosphotransferase) genes, which is the selective marker used for transgenic cell cultures of P.ginseng. It has been established that the nucleotide sequences of the rolC and nptII genes underwent mutagenesis during cultivation. Particularly, 1–4 nucleotide substitutions were found per sequence in the
540 and 798 bp segments of the complete rolC and nptII genes, respectively. Approximately half of these nucleotide substitutions caused changes in the structure of the predicted
gene product. In addition, we attempted to determine the rate of accumulation of these changes by comparison of DNA extracted
from P.ginseng cell cultures from 1995 to 2007. It was observed that the frequency of nucleotide substitutions for the rolC and nptII genes in 1995 was 1.21 ± 0.02 per 1,000 nucleotides analyzed, while in 2007, the nucleotide substitutions significantly increased
(1.37 ± 0.07 per 1,000 nucleotides analyzed). Analyzing the nucleotide substitutions, we found that substitution to G or to
C nucleotides significantly increased (in 1.9 times) in the rolC and nptII genes compared with P.ginsengactin gene. Finally, the level of nucleotide substitutions in the rolC gene was 1.1-fold higher when compared with the nptII gene. Thus, for the first time, we have experimentally demonstrated the level of nucleotide substitutions in transferred
genes in transgenic plant cell cultures. 相似文献
Biomass growth and ginsenoside production in cell suspension and adventitious roots of Panax ginseng C.A. Meyer cultures cultivated both in Erlenmayer flasks and a 3 dm3 bioreactor were studied. The maximum content of ginsenosides was found in the suspension culture cultivated in the bioreactor (4.34 % dry mass), however the saponin content was limited to two major ginsenosides, Rb1 and Rg1. The production of ginsenosides in adventitious roots was lower (1.45 or 1.72 % dry mass), nevertheless, the full range of ginsenosides was detected.This work was supported by 521/02/P064, COST 843.10, ME671 and Z4 055 905 projects. 相似文献
Evolutionary patterns of sequence divergence were analyzed in genes from the conifer genus Taxus (yew), encoding paclitaxel biosynthetic enzymes taxadiene synthase (TS) and 10-deacetylbaccatin III-10β-O-acetyltransferase
(DBAT). N-terminal fragments of TS, full-length DBAT and internal transcribed spacer (ITS) were amplified from 15 closely related Taxus species and sequenced. Premature stop codons were not found in TS and DBAT sequences. Codon usage bias was not found, suggesting that synonymous mutations are selectively neutral. TS and DBAT gene trees are not consistent with the ITS tree, where species formed monophyletic clades. In fact, for both genes, alleles
were sometimes shared across species and parallel amino acid substitutions were identified. While both TS and DBAT are, overall, under purifying selection, we identified a number of amino acids of TS under positive selection based on inference using maximum likelihood models. Positively selected amino acids in the N-terminal
region of TS suggest that this region might be more important for enzyme function than previously thought. Moreover, we identify
lineages with significantly elevated rates of amino acid substitution using a genetic algorithm. These findings demonstrate
that the pattern of adaptive paclitaxel biosynthetic enzyme evolution can be documented between closely related Taxus species, where species-specific taxane metabolism has evolved recently. 相似文献