Dendrobium nobile is an important medicinal and nutraceutical herb.Although the ingredients of D.nobile have been identified as polysaccharides,alkaloids,amino acids,flavonoids and bibenzyls,our understanding of the m...Dendrobium nobile is an important medicinal and nutraceutical herb.Although the ingredients of D.nobile have been identified as polysaccharides,alkaloids,amino acids,flavonoids and bibenzyls,our understanding of the metabolic pathways that regulate the synthesis of these compounds is limited.Here,we used transcriptomic and metabolic analyses to elucidate the genes and metabolites involved in the biosynthesis of carbohydrate and several secondary metabolites in the stems of D.nobile.A total of 1005 metabolites and 31,745 genes were detected in the stems of D.nobile.The majority of these metabolites and genes were involved in the metabolism of carbohydrates(fructose,mannose,glucose,xylulose and starch),while some were involved in the metabolism of secondary metabolites(alkaloids,β-tyrosine,ferulic acid,4-hydroxybenzoate and chrysin).Our predicted regulatory network indicated that five genes(AROG,PYK,DXS,ACEE and HMGCR) might play vital roles in the transition from carbohydrate to alkaloid synthesis.Correlation analysis identified that six genes(ALDO,PMM,BGLX,EGLC,XYLB and GLGA) were involved in carbohydrate metabolism,and two genes(ADT and CYP73A) were involved in secondary metabolite biosynthesis.Our analyses also indicated that phosphoenol-pyruvate(PEP) was a crucial bridge that connected carbohydrate to alkaloid biosynthesis.The regulatory network between carbohydrate and secondary metabolite biosynthesis established will provide important insights into the regulation of metabolites and biological systems in Dendrobium species.展开更多
Dendrobium nobile Lindl.alkaloids（DNLA）,the active ingredients of a traditional Chinese medicine Dendrobium,have been shown to have anti-oxidative effects,anti-inflammatory action,and protective effect on neurons ag...Dendrobium nobile Lindl.alkaloids（DNLA）,the active ingredients of a traditional Chinese medicine Dendrobium,have been shown to have anti-oxidative effects,anti-inflammatory action,and protective effect on neurons against oxygen-glucose deprivation.However,it is not clear whether DNLA reduces amyloid-beta（Aβ）-induced neuronal injury.In this study,cortical neurons were treated with DNLA at different concentrations（0.025,0.25,and 2.5 mg/L）for 24 hours,followed by administration of Aβ（25-35）（10μM）.Aβ（25-35） treatments increased cell injury as determined by the leakage of lactate dehydrogenase,which was accompanied by chromatin condensation and mitochondrial tumefaction.The damage caused by Aβ（25-35） on these cellular properties was markedly attenuated when cells were pretreated with DNLA.Treatment with Aβ（25-35）down-regulated the expressions of postsynaptic density-95 mRNA and decreased the protein expression of synaptophysin and postsynaptic density-95,all changes were significantly reduced by pretreatment of cells with DNLA.These findings suggest that DNLA reduces the cytotoxicity induced by Aβ（25-35） in rat primary cultured neurons.The protective mechanism that DNLA confers on the synaptic integrity of cultured neurons might be mediated,at least in part,through the upregulation of neurogenesis related proteins synaptophysin and postsynaptic density-95.展开更多
A new dendrobine-type alkaloid has been isolated from stems of Dendrobium nobile lindl.. Its structure has been identified on the basis of spectroscopic method.
Objective: To ascertain the influence of light intensity and water content of medium on the total dendrobine of Dendrobium nobile(D. nobile).Method: The principal component analysis combined with total dendrobine accu...Objective: To ascertain the influence of light intensity and water content of medium on the total dendrobine of Dendrobium nobile(D. nobile).Method: The principal component analysis combined with total dendrobine accumulation was conducted to assess the yield and quality of D. nobile in all treatments. In the experiment, D. nobile plants were cultivated in greenhouse as tested materials, and complete test of 9 treatments was adopted with relative light intensities 75.02%, 39.74%,29.93% and relative water content of medium 50%, 65%, 80%. The plants were treated in June and harvested till December. Indexes including agronomic traits, fresh weight and dry weight of stem and leaf, ash content, extract, and dendrobine were measured.Results: Under the light intensity treatments of 75.02% with 50%, 65%, 80% water content of medium, the basal stems of plants were comparatively thicker with more leaves, and the fresh weight and dry weight of stems and leaves were significantly higher than other 6 treatments.Leaves in all treatments contained dendrobine. Under the light intensity treatments of 75.02%with 50%, 65%, 80% water content of medium, dendrobine content of leaves was lower while dendrobine contents of other treatments were more than 0.60%. After comprehensive assessment through the principal component analysis and total dendrobine accumulation, the results showed that 3 treatments with relative light intensity of 75.02% ranked the top three.Conclusions: In brief, the moderately strong light intensity and water content of medium from low to medium can facilitate the growth and yield of D. nobile plants, while light intensity from moderately weak to weak can enhance the dendrobine content.展开更多
[Objectives]To improve the yield of flavonoids from Dendrobium nobile Lindl.[Methods]On the basis of four single-factor experiments of solid/liquid ratio,extraction temperature,extraction time and ethanol volume fract...[Objectives]To improve the yield of flavonoids from Dendrobium nobile Lindl.[Methods]On the basis of four single-factor experiments of solid/liquid ratio,extraction temperature,extraction time and ethanol volume fraction,the ultrasonic-assisted extraction process of total flavonoids from D.nobile Lindl.was optimized using quadratic general rotary unitized design,and the in-vitro anti-oxidant activity of the flavonoids extracted was evaluated preliminarily.[Results]The optimized extraction process for flavonoids in D.nobile Lindl.was as follows:extraction time 10 min,solid/liquid ratio 1∶15(g∶mL),extraction temperature 75℃and ethanol volume fraction 90%.According to the revised optimal process,6 repeated experiments were carried out,and the average yield of flavonoids was(0.5515±0.0004)mg/g,consistent with the predicted value of the model.The results of anti-oxidation experiment show that the flavonoids extracted from D.nobile Lindl.have better scavenging effect on ABTS and DPPH free radicals,and the scavenging activity is proportional to the mass concentration of the extract.[Conclusions]The optimized extraction process for flavonoids from D.nobile Lindl.is reasonable and feasible,and the flavonoids in D.nobile Lindl.have strong antioxidant activity.展开更多
Dendrobium nobile Lindl (D. nobile), a well-known precious herb, has a long history of use as a medicine and health food in China. Phytochemically, D. nobile has been found to contain various bioactive compounds, such...Dendrobium nobile Lindl (D. nobile), a well-known precious herb, has a long history of use as a medicine and health food in China. Phytochemically, D. nobile has been found to contain various bioactive compounds, such as alkaloids, bibenzyl, phenanthrene, phenylpropanoids, and polysaccharides. Its medicinal applications are closely correlated to its diverse pharmacological activities, including antitumor, anti-inflammatory, nervous system protective, antifatigue, hypoglycemic, and hypolipidemic actions. In this review, we provide a comprehensive summary of the main chemical constituents and pharmacological activities of D. nobile, as well as the underlying molecular mechanisms for its bioactivities. It is expected that this review will provide a helpful scientific reference for the development and use of D. nobile.展开更多
Seed dormancy and germination characteristics are important factors determining plant reproductive success, and may be expected to have a major influence on plant distribution. In this study, we aimed to explore the c...Seed dormancy and germination characteristics are important factors determining plant reproductive success, and may be expected to have a major influence on plant distribution. In this study, we aimed to explore the characteristics of seed dormancy and germination in two endemic Rheum species(Rheum nobile and Rheum alexandrae) in the Himalaya-Hengduan Mountains. To determine the type of dormancy,fresh seeds of the two species(one population each) were incubated in light at 25/15 and 15/5℃, and then dry after-ripening(DAR) seeds were incubated on water agar substrate with or without GA_3. To determine the effect of temperature and light on germination, DAR seeds of the two species(two populations each) were incubated both in the light and in the dark at several temperatures, including constant and alternating temperatures. Base temperature(T_b) and thermal times for 50% germination(θ_(50)) were calculated. DAR released physiological dormancy(PD), increasing final germination at 15/5℃ and widening the range of germination temperatures from higher to lower, indicative of type 2 non-deep PD for the two Rheum species. Light had no significant effect on germination of seeds from the two species(two populations each). Seeds of the two species germinated significantly better(>80%) at medium temperatures(10-25℃) than at extreme low(5℃) or high(35℃) temperatures. Alternating temperatures(25/15 and 15/5℃) did not significantly increase the final germination of the two species either in the light and in the dark, but it promoted seed germination more quickly than corresponding constant temperatures in the light in both Rh. alexandrae populations, especially at 15/5℃. Germination in response to temperature was well described by the thermal-time model at suboptimal temperatures. The estimated Tbvalues were 1 and 0.9℃, respectively, in two Rh. nobile populations; 4 and 4.1℃,respectively, in two Rh. alexandrae populations; θ_(50)(thermal time) were 100 and 125℃d, respectively in two Rh. nobile populations; 76.92 and 83.33℃d, respectively in two Rh. alexandrae populations. The dormancy type, and germination responses to temperature and light condition does not explain why the two Rheum species are distributed in contrasting habitats. However, these findings reflect an advantageous germination strategy of these two Rheum species to adapt to the same alpine environments.展开更多
Performance of Turbo-Codes in communication channels with impulsive noise is analyzed. First, mathematical model of impulsive noise is presented because it has non-Gaussian nature and is found in many wireless channel...Performance of Turbo-Codes in communication channels with impulsive noise is analyzed. First, mathematical model of impulsive noise is presented because it has non-Gaussian nature and is found in many wireless channels due to impulsive phenomena of radio-frequency interference. Then, with linear Log-MAP decoding algorithm for its low complexity, Turbo-Codes are adopted and analyzed in such communication channels. To confirm the performance of the proposed method, simulations on both static and fully interleaved flat Rayleigh fading channels with impulsive noise have been carried out. It is shown that Turbo-Codes have a better performance than the conventional methods （e.g. convolutionally coded system）.展开更多
Interactions between an isolate of dark septate endophytes （DSE） and roots of Dendrobium nobile Lindl. seedlings are reported in this paper. The isolate was obtained from orchid mycorrhizas on Dendrobium sp. in subt...Interactions between an isolate of dark septate endophytes （DSE） and roots of Dendrobium nobile Lindl. seedlings are reported in this paper. The isolate was obtained from orchid mycorrhizas on Dendrobium sp. in subtropical forest. The fungus formed typical orchid mycorrhiza in aseptic co-culture with D. nobile seedlings on modified Murashige-Skoog （MMS） medium. Anatomic observations of the infected roots showed that the DSE hyphae invaded the velamen layer, passed through passage cells in exodermis, entered the cortex cells, and then formed fungal pelotons of orchid mycorrhiza. D. nobile seedlings＇ plant height, stem diameter, new roots number and biomass were greatly enhanced by inoculating the fungus to seedlings. The fungus was identified as Leptodontidium by sequencing the polymerase chain reaction-amplified rDNA ITS1-5,8S-ITS2 （internal transcribed spacer （ITS）） regions and comparison with similar taxa.展开更多
基金supported by the Project for Innovation Team of Yunnan Province (202105AE160012)the Project for Construction of International Flower Technology Innovation Center and Achievement Industrialization (2019ZG006)+2 种基金the Project for the Germplasm Bank of Wild Speciesthe KC Wong Education Foundation,CASthe project for High-level Talent Training Plan of Yunnan Province
文摘Dendrobium nobile is an important medicinal and nutraceutical herb.Although the ingredients of D.nobile have been identified as polysaccharides,alkaloids,amino acids,flavonoids and bibenzyls,our understanding of the metabolic pathways that regulate the synthesis of these compounds is limited.Here,we used transcriptomic and metabolic analyses to elucidate the genes and metabolites involved in the biosynthesis of carbohydrate and several secondary metabolites in the stems of D.nobile.A total of 1005 metabolites and 31,745 genes were detected in the stems of D.nobile.The majority of these metabolites and genes were involved in the metabolism of carbohydrates(fructose,mannose,glucose,xylulose and starch),while some were involved in the metabolism of secondary metabolites(alkaloids,β-tyrosine,ferulic acid,4-hydroxybenzoate and chrysin).Our predicted regulatory network indicated that five genes(AROG,PYK,DXS,ACEE and HMGCR) might play vital roles in the transition from carbohydrate to alkaloid synthesis.Correlation analysis identified that six genes(ALDO,PMM,BGLX,EGLC,XYLB and GLGA) were involved in carbohydrate metabolism,and two genes(ADT and CYP73A) were involved in secondary metabolite biosynthesis.Our analyses also indicated that phosphoenol-pyruvate(PEP) was a crucial bridge that connected carbohydrate to alkaloid biosynthesis.The regulatory network between carbohydrate and secondary metabolite biosynthesis established will provide important insights into the regulation of metabolites and biological systems in Dendrobium species.
基金financially supported by the National Natural Science Foundation of China,No.81473201the Natural Science Foundation of Educational Commission of Guizhou Province of China,No.2010043+1 种基金the Science and Technology Foundation of Guizhou Province of China,No.JZ[2014]2016the Modernization of Traditional Chinese Medicine Project of Guizhou Province of China,No.[2011]5086
文摘Dendrobium nobile Lindl.alkaloids（DNLA）,the active ingredients of a traditional Chinese medicine Dendrobium,have been shown to have anti-oxidative effects,anti-inflammatory action,and protective effect on neurons against oxygen-glucose deprivation.However,it is not clear whether DNLA reduces amyloid-beta（Aβ）-induced neuronal injury.In this study,cortical neurons were treated with DNLA at different concentrations（0.025,0.25,and 2.5 mg/L）for 24 hours,followed by administration of Aβ（25-35）（10μM）.Aβ（25-35） treatments increased cell injury as determined by the leakage of lactate dehydrogenase,which was accompanied by chromatin condensation and mitochondrial tumefaction.The damage caused by Aβ（25-35） on these cellular properties was markedly attenuated when cells were pretreated with DNLA.Treatment with Aβ（25-35）down-regulated the expressions of postsynaptic density-95 mRNA and decreased the protein expression of synaptophysin and postsynaptic density-95,all changes were significantly reduced by pretreatment of cells with DNLA.These findings suggest that DNLA reduces the cytotoxicity induced by Aβ（25-35） in rat primary cultured neurons.The protective mechanism that DNLA confers on the synaptic integrity of cultured neurons might be mediated,at least in part,through the upregulation of neurogenesis related proteins synaptophysin and postsynaptic density-95.
文摘A new dendrobine-type alkaloid has been isolated from stems of Dendrobium nobile lindl.. Its structure has been identified on the basis of spectroscopic method.
基金supported by Natural Science Foundation of China(No.81603237)Joint Funding Project of Guizhou Province[QKH LH Zi(2015)No.7670]+4 种基金Youth Science and Technology Talent Development Project of Education Department in Guizhou Province[QJH KY Zi(2016)No.119]Natural Science Foundation of Guizhou Province[QKH Basics(2017)No.1403]Talent Base Project of Organization Department in Guizhou Province[QRLF(2013)No.15]Key Discipline Project of Education Department in Guizhou Province[QXWH Zi ZDXK(2014)No.8]Regular Higher Education Institution Project of Key Laboratory of Genetic Improvement and Physiology and Ecology of Grain and Oil Crops of Guizhou Province of China[Grant No.KY(2015)333]
文摘Objective: To ascertain the influence of light intensity and water content of medium on the total dendrobine of Dendrobium nobile(D. nobile).Method: The principal component analysis combined with total dendrobine accumulation was conducted to assess the yield and quality of D. nobile in all treatments. In the experiment, D. nobile plants were cultivated in greenhouse as tested materials, and complete test of 9 treatments was adopted with relative light intensities 75.02%, 39.74%,29.93% and relative water content of medium 50%, 65%, 80%. The plants were treated in June and harvested till December. Indexes including agronomic traits, fresh weight and dry weight of stem and leaf, ash content, extract, and dendrobine were measured.Results: Under the light intensity treatments of 75.02% with 50%, 65%, 80% water content of medium, the basal stems of plants were comparatively thicker with more leaves, and the fresh weight and dry weight of stems and leaves were significantly higher than other 6 treatments.Leaves in all treatments contained dendrobine. Under the light intensity treatments of 75.02%with 50%, 65%, 80% water content of medium, dendrobine content of leaves was lower while dendrobine contents of other treatments were more than 0.60%. After comprehensive assessment through the principal component analysis and total dendrobine accumulation, the results showed that 3 treatments with relative light intensity of 75.02% ranked the top three.Conclusions: In brief, the moderately strong light intensity and water content of medium from low to medium can facilitate the growth and yield of D. nobile plants, while light intensity from moderately weak to weak can enhance the dendrobine content.
基金Key Science and Technology Program of Science&Technology Department of Henan Province(172102310211,182102110166,192102310087,202102310478)Key Scientific and Technological Research Project for Colleges and Universities(18A180026,20B350006)+1 种基金Starting Foundation of Pingdingshan University for High-level Talents(PXY-BSQD-2018011,PXY-BSQD-2018010)Cultivation Fund of Pingdingshan University(PXY-PYJJ-2019007)。
文摘[Objectives]To improve the yield of flavonoids from Dendrobium nobile Lindl.[Methods]On the basis of four single-factor experiments of solid/liquid ratio,extraction temperature,extraction time and ethanol volume fraction,the ultrasonic-assisted extraction process of total flavonoids from D.nobile Lindl.was optimized using quadratic general rotary unitized design,and the in-vitro anti-oxidant activity of the flavonoids extracted was evaluated preliminarily.[Results]The optimized extraction process for flavonoids in D.nobile Lindl.was as follows:extraction time 10 min,solid/liquid ratio 1∶15(g∶mL),extraction temperature 75℃and ethanol volume fraction 90%.According to the revised optimal process,6 repeated experiments were carried out,and the average yield of flavonoids was(0.5515±0.0004)mg/g,consistent with the predicted value of the model.The results of anti-oxidation experiment show that the flavonoids extracted from D.nobile Lindl.have better scavenging effect on ABTS and DPPH free radicals,and the scavenging activity is proportional to the mass concentration of the extract.[Conclusions]The optimized extraction process for flavonoids from D.nobile Lindl.is reasonable and feasible,and the flavonoids in D.nobile Lindl.have strong antioxidant activity.
文摘Dendrobium nobile Lindl (D. nobile), a well-known precious herb, has a long history of use as a medicine and health food in China. Phytochemically, D. nobile has been found to contain various bioactive compounds, such as alkaloids, bibenzyl, phenanthrene, phenylpropanoids, and polysaccharides. Its medicinal applications are closely correlated to its diverse pharmacological activities, including antitumor, anti-inflammatory, nervous system protective, antifatigue, hypoglycemic, and hypolipidemic actions. In this review, we provide a comprehensive summary of the main chemical constituents and pharmacological activities of D. nobile, as well as the underlying molecular mechanisms for its bioactivities. It is expected that this review will provide a helpful scientific reference for the development and use of D. nobile.
基金supported by National Key Research and Development Program of China (2017YFC0505201)NSFC (grant 31670206 to Z.-M. L. and 31570228 to B. S.),major Program of NSFC (grant 31590823 to H. S.)+1 种基金the Orientation Training Programme for Postdoctoral Fellows from Yunnan Province to D.-L. P.the Young Academic and Technical Leader Raising Foundation of Yunnan Province to B. S.
文摘Seed dormancy and germination characteristics are important factors determining plant reproductive success, and may be expected to have a major influence on plant distribution. In this study, we aimed to explore the characteristics of seed dormancy and germination in two endemic Rheum species(Rheum nobile and Rheum alexandrae) in the Himalaya-Hengduan Mountains. To determine the type of dormancy,fresh seeds of the two species(one population each) were incubated in light at 25/15 and 15/5℃, and then dry after-ripening(DAR) seeds were incubated on water agar substrate with or without GA_3. To determine the effect of temperature and light on germination, DAR seeds of the two species(two populations each) were incubated both in the light and in the dark at several temperatures, including constant and alternating temperatures. Base temperature(T_b) and thermal times for 50% germination(θ_(50)) were calculated. DAR released physiological dormancy(PD), increasing final germination at 15/5℃ and widening the range of germination temperatures from higher to lower, indicative of type 2 non-deep PD for the two Rheum species. Light had no significant effect on germination of seeds from the two species(two populations each). Seeds of the two species germinated significantly better(>80%) at medium temperatures(10-25℃) than at extreme low(5℃) or high(35℃) temperatures. Alternating temperatures(25/15 and 15/5℃) did not significantly increase the final germination of the two species either in the light and in the dark, but it promoted seed germination more quickly than corresponding constant temperatures in the light in both Rh. alexandrae populations, especially at 15/5℃. Germination in response to temperature was well described by the thermal-time model at suboptimal temperatures. The estimated Tbvalues were 1 and 0.9℃, respectively, in two Rh. nobile populations; 4 and 4.1℃,respectively, in two Rh. alexandrae populations; θ_(50)(thermal time) were 100 and 125℃d, respectively in two Rh. nobile populations; 76.92 and 83.33℃d, respectively in two Rh. alexandrae populations. The dormancy type, and germination responses to temperature and light condition does not explain why the two Rheum species are distributed in contrasting habitats. However, these findings reflect an advantageous germination strategy of these two Rheum species to adapt to the same alpine environments.
文摘Performance of Turbo-Codes in communication channels with impulsive noise is analyzed. First, mathematical model of impulsive noise is presented because it has non-Gaussian nature and is found in many wireless channels due to impulsive phenomena of radio-frequency interference. Then, with linear Log-MAP decoding algorithm for its low complexity, Turbo-Codes are adopted and analyzed in such communication channels. To confirm the performance of the proposed method, simulations on both static and fully interleaved flat Rayleigh fading channels with impulsive noise have been carried out. It is shown that Turbo-Codes have a better performance than the conventional methods （e.g. convolutionally coded system）.
基金Supported by the National Science Fund of China for Distinguished YoungScholars(30325047).
文摘Interactions between an isolate of dark septate endophytes （DSE） and roots of Dendrobium nobile Lindl. seedlings are reported in this paper. The isolate was obtained from orchid mycorrhizas on Dendrobium sp. in subtropical forest. The fungus formed typical orchid mycorrhiza in aseptic co-culture with D. nobile seedlings on modified Murashige-Skoog （MMS） medium. Anatomic observations of the infected roots showed that the DSE hyphae invaded the velamen layer, passed through passage cells in exodermis, entered the cortex cells, and then formed fungal pelotons of orchid mycorrhiza. D. nobile seedlings＇ plant height, stem diameter, new roots number and biomass were greatly enhanced by inoculating the fungus to seedlings. The fungus was identified as Leptodontidium by sequencing the polymerase chain reaction-amplified rDNA ITS1-5,8S-ITS2 （internal transcribed spacer （ITS）） regions and comparison with similar taxa.
