The genetic diversity of Artemisia halodendron(Asteraceae), a constructive and dominant species in Horqin Sandy Land,was investigated to examine the genetic relationships with different hydrothermal regions in Horqin ...The genetic diversity of Artemisia halodendron(Asteraceae), a constructive and dominant species in Horqin Sandy Land,was investigated to examine the genetic relationships with different hydrothermal regions in Horqin Sandy Land. We sequenced chloroplast DNA(cp DNA) fragments(trn L–F) of 243 plants from 10 populations across the Horqin Sandy Land.The analyses of cp DNA variation identified seven haplotypes. A low level of haplotype diversity(H_d=0.706) and nucleotide diversity(π=0.0013) was detected. Haplotypes clustered into two tentative clades. Low genetic differentiation among regions was consistently indicated by hierarchical analyses of molecular variance(AMOVA). Across the sampled populations, the haplotype distributions were differentiated with hydrothermal gradients.展开更多
The aim of the present study is to investigate the difference between ITS sequences ofArtemisia halodendron Turcz. from differ- ent habitat gradients in Horqin Sandy Land, with Artemisia depauperata Krasch. selected a...The aim of the present study is to investigate the difference between ITS sequences ofArtemisia halodendron Turcz. from differ- ent habitat gradients in Horqin Sandy Land, with Artemisia depauperata Krasch. selected as the outgroup. Results indicate that the total length ofA. halodendron ITS is 696 bp, the lengths of unaligned ITS-1 and ITS-2 sequences varied from 253 to 256 bp and 264 to 269 bp, respectively, and GC content of ITS-1 and ITS-2 sequences ranged from 54.02% to 54.77% and 56.75% to 58.64%, respectively. This indicates a high difference of length and composition of sequences in ITS-1 than ITS-2. The genetic identity between ITS sequences ofA. halodendron from nine populations ranged from 85.7% to 99.7% which indicates some genetic dif- ferentiation between sequences. In the maximum parsimony （MP） tree, most ITS sequences from A. halodendron show two major clades： Clade I and Clade II, with Clade II older than Clade I. The order is subp4→ subpl → subp2 → subp3→ subp8 → subp6 → subp7 → subp9 → subp5, and corresponding habitat order is： inter-dune lowlands → semi-mobile dune → mobile dune →semi-fixed dune -→fixed dune. This indicates a close relation between the evolutionary processes ofA. halodendron and deserti- fication forming processes and ecological restoration processes of Horqin Sandy Land.展开更多
Individuals with Glucose-6-phosphate dehydrogenase (G6PD) deficiency are susceptible to hemolytic anemia when exposed to pro-oxidant substances. This study investigates the hemolytic impact of Artemisia annua (A. annu...Individuals with Glucose-6-phosphate dehydrogenase (G6PD) deficiency are susceptible to hemolytic anemia when exposed to pro-oxidant substances. This study investigates the hemolytic impact of Artemisia annua (A. annua) extracts in G6PD-deficient subjects through a mixed experimental approach. In the in vitro phase, red blood cells from G6PD-deficient individuals and rats induced with Dehydroepiandrosterone (DHEA) were exposed to various concentrations of A. annua infusion, with distilled water and physiological saline as positive and negative controls respectively. The in vivo study involved G6PD-deficient Wistar rats divided into three groups receiving A. annua infusion, quinine (positive control), and distilled water (negative control) via gavage. Blood samples were collected for biochemical and hematological analyses. Notably, at a 40% concentration of A. annua infusion, there was a significant increase in the hemolysis rate of G6PD-deficient red blood cells compared to controls (p A. annua exhibited elevated aspartate aminotransferase (129.25 ± 4.55 U/L vs. 80.09 ± 4.03 U/L;p A. annua infusion tested positive for saponins. These findings underscore the risk of hemolysis in G6PD-deficient individuals upon ingesting A. annua.展开更多
Background:Artemisia vulgaris,a medicinal aromatic plant,is widely used as a food item,tonic pharmaceutical,and cosmetic industry additive owing to its antibacterial,antihypertensive,hepatoprotective,antioxidant,and a...Background:Artemisia vulgaris,a medicinal aromatic plant,is widely used as a food item,tonic pharmaceutical,and cosmetic industry additive owing to its antibacterial,antihypertensive,hepatoprotective,antioxidant,and antispasmodic properties.But the effect of different geographic locations on the chemical composition and bioactivities of its extracts is unclear.Methods:Biological activities of essential oils and ethanol extracts of three varieties of Artemisia vulgaris leaves,which are grown in Shanxi province China,were studied.Results:Gas chromatography-mass spectrometry analysis revealed that the main components of essential oils were terpenes and ketones.Essential oils and ethanol extract of Artemisia vulgaris leaves possessed good antioxidant activities,and their half maximal inhibitory concentrations determined using 1,1-diphenyl-2-picrylhydrazyl and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate)assays were 57.0 and 22.9μg/mL,respectively.The essential oils also exhibited remarkable antibacterial activity against three foodborne pathogenic bacterial strains.The ethanol extract presented a high anticancer activity against the MGC-803 human gastric cancer cell line.Conclusion:These biological activities were well correlated with the composition of the extract and EOs,which in turn is affected by the genetic composition of Artemisia vulgaris and geographic location and diverse climatic condition under which it is grown.These findings demonstrate the remarkable potential of Artemisia vulgaris as a valuable source of antioxidant,antibacterial,and anticancer agents.展开更多
All nuclei in mesophyll cells of Artemisia marschalliana are located in vacuoles and occupy up to 90% of their volume. The ultrastructural organization of chromatin in nuclei shows different degrees of its decondensat...All nuclei in mesophyll cells of Artemisia marschalliana are located in vacuoles and occupy up to 90% of their volume. The ultrastructural organization of chromatin in nuclei shows different degrees of its decondensation, up to complete separation of DNA from histones. It is possible that the separation of DNA from histones enables Artemisia to grow in soils with high salinity.展开更多
[Objectives]This paper was to figure out whether the dominant bacterial community has the role and effect of bacterial community and its defense mechanism against potential pathogenic fungi in Artemisia annua,and thus...[Objectives]This paper was to figure out whether the dominant bacterial community has the role and effect of bacterial community and its defense mechanism against potential pathogenic fungi in Artemisia annua,and thus establish a systematic model of bacteria-fungus-plant.[Methods]Fifty-eight strains of bacteria and one strain of pathogenic fungi,Globisporangium ultimatum,were used for the experiments.These 58 bacterial strains were assembled into a bacterial community,and the bacteria with abundance in the top 1%were reassembled into a dominant bacterial community as measured by 16S rDNA.[Results]The growth of A.annua seedlings inoculated with bacterial communities and pathogenic fungi or dominant bacterial communities and pathogenic fungi was significantly better than that of A.annua seedlings inoculated with pathogenic fungi during in vitro confrontation,which was evident in both enzymatic and non-enzymatic antioxidant assays.[Conclusions]The results suggest that the dominant bacterial community has a crucial role as a representative core microbial community of synthetic bacterial community,which can protect plants by interfering with the growth of phytopathogenic fungi mediated by chemical signals,and can be used as the main synthetic community of biocides to achieve the effect of biocontrol.展开更多
Preliminary exploration of the soothing,oil control,acne removing effects and its mechanisms of Artemisia annua extract.The soothing effect of Artemisia annua extract was tested by hyaluronidase biochemical reaction.T...Preliminary exploration of the soothing,oil control,acne removing effects and its mechanisms of Artemisia annua extract.The soothing effect of Artemisia annua extract was tested by hyaluronidase biochemical reaction.The soothing and oil-controlling effects were investigated by cell model.The inhibitory effect on propionibacterium acnes was studied by suspension quantification.The results showed that Artemisia annua extract could effectively inhibit the degradation of hyaluronic acid(P<0.01).Artemisia annua extract significantly inhibited the secretion of inflammatory cytokines TNF-αand IL-6 in RAW264.7 cells(P<0.05).Artemisia annua extract at 0.5%,0.25%,0.125%could significantly inhibit the secretion of oil by SZ95 cells(P<0.05).The minimum inhibitory concentration of Artemisia annua extract against propionibacterium acnes was 0.625%,and the inhibitory rate against propionibacterium acnes increased with the increase of the concentration of Artemisia annua extract.In summary,Artemisia annua extract can achieve acne efficacy through soothing and oil control,and this function may be achieved by reducing hyaluronic acid degradation,inhibiting inflammatory pathways produced by inflammatory factors TNF-αand IL-6,inhibiting oil secretion,and inhibiting the growth of propionibacterium acnes.展开更多
The artemisinin accumulation in the hairy root cultures of Artemisia annua L. was enhanced via a treatment of three fungal elicitors separately ( Verticillium dahliae Kleb., Rhizopus stolonifer (Ehrenb. ex ...The artemisinin accumulation in the hairy root cultures of Artemisia annua L. was enhanced via a treatment of three fungal elicitors separately ( Verticillium dahliae Kleb., Rhizopus stolonifer (Ehrenb. ex Fr.) Vuill and Colletotrichum dematium (Pers.) Grove). Among these three elicitors, V. dahliae had the highest inducing efficiency, but none of them manifests any noticeable effects on the cell growth of the hairy root cultures. The artemisinin content of the hairy root cultures treated with V. dahliae elicitor was 1.12 mg/g DW, which was 45% higher than the control (0.77 mg/g DW). The results showed that elicitation was dependent on the elicitor concentration, the incubation period and the physiological stage at which the hairy root cultures were treated. In addition, the authors found that for V. dahliae , the optimum concentration was 0.4 mg carbohydrate per millilitre medium, the strongest response of A. annua hairy root cultures to the elicitation was at the late exponential growth stage, and the highest artemisinin content of the hairy root cultures was on the 4th day post treatment.展开更多
[ Objective ] The objective of this study is to explore a rapid and efficient method of extracting genomic DNA from Artemisia abrotanum. [ Method] Three methods of Cutting Method, Liquid Nitrogen Method and Quartz San...[ Objective ] The objective of this study is to explore a rapid and efficient method of extracting genomic DNA from Artemisia abrotanum. [ Method] Three methods of Cutting Method, Liquid Nitrogen Method and Quartz Sand Method based on SDS method were employed to extract Artemisia abrotanum genomlc DNA from tender leaf at seedling stage, tender spike and old leaf at heading stage. The obtained DNAs were detected by absorbance detection, agarose gel and PCR amplification. [ Result ] Cutting Method performed better than the other two methods compared in purity, extracting cycle and cost, accordingly more suitable for PCR amplification. The results also show that young spike is the best material for extracting genomic DNA from Artemisia Annua.展开更多
A 1 539 by squalene synthase (AaSQS) cDNA was cloned from a high-yield Artemisia annua L. strain 001 by reverse transcription-polymerise chain reaction (RT-PCR). The amino acid sequence of AaSQS is 70%, 77%, 44% and 3...A 1 539 by squalene synthase (AaSQS) cDNA was cloned from a high-yield Artemisia annua L. strain 001 by reverse transcription-polymerise chain reaction (RT-PCR). The amino acid sequence of AaSQS is 70%, 77%, 44% and 39%a identical to that of squalene synthases from Arabidopsis thaliana, tobacco, human and yeast, respectively. The AaSQS genomic DNA has a complex organization containing 14 exons and 13 introns. Full-length or C-terminal truncated cDNA was subcloned into prokaryotic expression vector pET30a and the constructed plasmid was introduced to Escherichia coli strain BL21 (DE3) for induced overexpression. No squalene synthase protein with expected molecular mass was observed in E. cola containing the putative full-length squalene synthase cDNA, however, overexpression in E. coli was achieved by truncating 30 amino acids of hydrophobic region at the carboxy terminus.展开更多
Biomass and net primary productivity （NPP） are two important parameters in determining ecosystem carbon pool and carbon sequestration. The biomass storage and NPP in desert shrubland of Artemisia ordosica on Ordos P...Biomass and net primary productivity （NPP） are two important parameters in determining ecosystem carbon pool and carbon sequestration. The biomass storage and NPP in desert shrubland of Artemisia ordosica on Ordos Plateau were investigated with method of harvesting standard size shrub in the growing season （June-October） of 2006. Results indicated that above- and belowground biomass of the same size shrubs showed no significant variation in the growing season （p〉0.1）, but annual biomass varied significantly （p〈 0.01）. In the A. ordosica community, shrub biomass storage was 699.76-1246.40 g.m^-2 and annual aboveground NPP was 224.09 g-m^-2·a^-1. Moreover, shrub biomass and NPP were closely related with shrub dimensions （cover and height） and could be well predicted by shrub volume using power regression.展开更多
The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (la...The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (later growth phase) were exposed to the elicitor (20 mg/L) for 4 d, the maximum content of artemisinin reached 1.15 mg/g, a 64.29% increment over the control. The electron X-ray microanalysis disclosed the rapid accumulation of Ca 2+ in the elicited cortical cells of hairy root. The electronic microscope observation revealed the high electron density area in vacuole of elicited cells. During the first day of elicitation the peroxidase activity of hairy roots was improved sharply. Some cellular morphological changes including cell shrinkage, condensation of cytoplasm and nuclear fragmentation, coincident with the appearance of DNA ladders, were observed after the third day of elicitation. It was suggested that the oligosaccharide elicitor triggered the programmed cell death, which may provide the substance or chemical signal for artemisinin biosynthesis.展开更多
A 1 886 bp full-length sesquiterpene synthase (AaSES) cDNA was cloned front a high-yield Artemisia annua L. strain 001 by a rapid amplification of cDNA end (RACE) strategy. AaSES is 59% identical to Artemisia cyclase ...A 1 886 bp full-length sesquiterpene synthase (AaSES) cDNA was cloned front a high-yield Artemisia annua L. strain 001 by a rapid amplification of cDNA end (RACE) strategy. AaSES is 59% identical to Artemisia cyclase cDNA clone cASC125, 50% identical to epi-cedrol synthase from A. annua , 48% identical to amorpha-4, 11-diene synthase from A. annua, 39% identical to the 5-epi-aristolechene synthase from tabacco, 38 % identical to vetispiradiene synthase front H. muticus, 41 % identical to the, delta-cadinene synthase from cotton. The coding region of the cDNA was inserted into a procaryotic expression vector pET-30a and overexpressed in E. coli BL21 ( DE3). The cyclase proteins extracted front bacterial culture were found largely in an insoluble protein fraction. AaSES expresses in leaves, stems a-rid flowers, not in roots as indicated by Northern blotting analysis.展开更多
基金supported by research projects 2016YFC0500907,2017FY100205,41201561,Y551821001,and 145RJYA269
文摘The genetic diversity of Artemisia halodendron(Asteraceae), a constructive and dominant species in Horqin Sandy Land,was investigated to examine the genetic relationships with different hydrothermal regions in Horqin Sandy Land. We sequenced chloroplast DNA(cp DNA) fragments(trn L–F) of 243 plants from 10 populations across the Horqin Sandy Land.The analyses of cp DNA variation identified seven haplotypes. A low level of haplotype diversity(H_d=0.706) and nucleotide diversity(π=0.0013) was detected. Haplotypes clustered into two tentative clades. Low genetic differentiation among regions was consistently indicated by hierarchical analyses of molecular variance(AMOVA). Across the sampled populations, the haplotype distributions were differentiated with hydrothermal gradients.
基金financially supported by research projects 41201561, 2011BAC07B02, Y351151001, 41071185 and 31170413
文摘The aim of the present study is to investigate the difference between ITS sequences ofArtemisia halodendron Turcz. from differ- ent habitat gradients in Horqin Sandy Land, with Artemisia depauperata Krasch. selected as the outgroup. Results indicate that the total length ofA. halodendron ITS is 696 bp, the lengths of unaligned ITS-1 and ITS-2 sequences varied from 253 to 256 bp and 264 to 269 bp, respectively, and GC content of ITS-1 and ITS-2 sequences ranged from 54.02% to 54.77% and 56.75% to 58.64%, respectively. This indicates a high difference of length and composition of sequences in ITS-1 than ITS-2. The genetic identity between ITS sequences ofA. halodendron from nine populations ranged from 85.7% to 99.7% which indicates some genetic dif- ferentiation between sequences. In the maximum parsimony （MP） tree, most ITS sequences from A. halodendron show two major clades： Clade I and Clade II, with Clade II older than Clade I. The order is subp4→ subpl → subp2 → subp3→ subp8 → subp6 → subp7 → subp9 → subp5, and corresponding habitat order is： inter-dune lowlands → semi-mobile dune → mobile dune →semi-fixed dune -→fixed dune. This indicates a close relation between the evolutionary processes ofA. halodendron and deserti- fication forming processes and ecological restoration processes of Horqin Sandy Land.
文摘Individuals with Glucose-6-phosphate dehydrogenase (G6PD) deficiency are susceptible to hemolytic anemia when exposed to pro-oxidant substances. This study investigates the hemolytic impact of Artemisia annua (A. annua) extracts in G6PD-deficient subjects through a mixed experimental approach. In the in vitro phase, red blood cells from G6PD-deficient individuals and rats induced with Dehydroepiandrosterone (DHEA) were exposed to various concentrations of A. annua infusion, with distilled water and physiological saline as positive and negative controls respectively. The in vivo study involved G6PD-deficient Wistar rats divided into three groups receiving A. annua infusion, quinine (positive control), and distilled water (negative control) via gavage. Blood samples were collected for biochemical and hematological analyses. Notably, at a 40% concentration of A. annua infusion, there was a significant increase in the hemolysis rate of G6PD-deficient red blood cells compared to controls (p A. annua exhibited elevated aspartate aminotransferase (129.25 ± 4.55 U/L vs. 80.09 ± 4.03 U/L;p A. annua infusion tested positive for saponins. These findings underscore the risk of hemolysis in G6PD-deficient individuals upon ingesting A. annua.
基金This work was financially supported by the National Natural Science Foundation of China(Grant No.32001817)the Science and Technology Innovation Plan of Colleges and Universities of Shanxi Province(2020L0298)the College student innovation project of North University of China and the start-up funds for scientific research at North University of China(No.304-1101285714).
文摘Background:Artemisia vulgaris,a medicinal aromatic plant,is widely used as a food item,tonic pharmaceutical,and cosmetic industry additive owing to its antibacterial,antihypertensive,hepatoprotective,antioxidant,and antispasmodic properties.But the effect of different geographic locations on the chemical composition and bioactivities of its extracts is unclear.Methods:Biological activities of essential oils and ethanol extracts of three varieties of Artemisia vulgaris leaves,which are grown in Shanxi province China,were studied.Results:Gas chromatography-mass spectrometry analysis revealed that the main components of essential oils were terpenes and ketones.Essential oils and ethanol extract of Artemisia vulgaris leaves possessed good antioxidant activities,and their half maximal inhibitory concentrations determined using 1,1-diphenyl-2-picrylhydrazyl and 2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate)assays were 57.0 and 22.9μg/mL,respectively.The essential oils also exhibited remarkable antibacterial activity against three foodborne pathogenic bacterial strains.The ethanol extract presented a high anticancer activity against the MGC-803 human gastric cancer cell line.Conclusion:These biological activities were well correlated with the composition of the extract and EOs,which in turn is affected by the genetic composition of Artemisia vulgaris and geographic location and diverse climatic condition under which it is grown.These findings demonstrate the remarkable potential of Artemisia vulgaris as a valuable source of antioxidant,antibacterial,and anticancer agents.
文摘All nuclei in mesophyll cells of Artemisia marschalliana are located in vacuoles and occupy up to 90% of their volume. The ultrastructural organization of chromatin in nuclei shows different degrees of its decondensation, up to complete separation of DNA from histones. It is possible that the separation of DNA from histones enables Artemisia to grow in soils with high salinity.
基金Supported by Science and Technology Plan Project of Guizhou Province,China(QKH JC[2020]1Y179)Key Field Project of Education Department of Guizhou Province(QJHKYZ[2021]044)+1 种基金Forestry Research Project of Guizhou Province(QLKH[2021]11)Project of Guizhou Provincial Characteristic Key Laboratory(QJHKY[2021]002).
文摘[Objectives]This paper was to figure out whether the dominant bacterial community has the role and effect of bacterial community and its defense mechanism against potential pathogenic fungi in Artemisia annua,and thus establish a systematic model of bacteria-fungus-plant.[Methods]Fifty-eight strains of bacteria and one strain of pathogenic fungi,Globisporangium ultimatum,were used for the experiments.These 58 bacterial strains were assembled into a bacterial community,and the bacteria with abundance in the top 1%were reassembled into a dominant bacterial community as measured by 16S rDNA.[Results]The growth of A.annua seedlings inoculated with bacterial communities and pathogenic fungi or dominant bacterial communities and pathogenic fungi was significantly better than that of A.annua seedlings inoculated with pathogenic fungi during in vitro confrontation,which was evident in both enzymatic and non-enzymatic antioxidant assays.[Conclusions]The results suggest that the dominant bacterial community has a crucial role as a representative core microbial community of synthetic bacterial community,which can protect plants by interfering with the growth of phytopathogenic fungi mediated by chemical signals,and can be used as the main synthetic community of biocides to achieve the effect of biocontrol.
文摘Preliminary exploration of the soothing,oil control,acne removing effects and its mechanisms of Artemisia annua extract.The soothing effect of Artemisia annua extract was tested by hyaluronidase biochemical reaction.The soothing and oil-controlling effects were investigated by cell model.The inhibitory effect on propionibacterium acnes was studied by suspension quantification.The results showed that Artemisia annua extract could effectively inhibit the degradation of hyaluronic acid(P<0.01).Artemisia annua extract significantly inhibited the secretion of inflammatory cytokines TNF-αand IL-6 in RAW264.7 cells(P<0.05).Artemisia annua extract at 0.5%,0.25%,0.125%could significantly inhibit the secretion of oil by SZ95 cells(P<0.05).The minimum inhibitory concentration of Artemisia annua extract against propionibacterium acnes was 0.625%,and the inhibitory rate against propionibacterium acnes increased with the increase of the concentration of Artemisia annua extract.In summary,Artemisia annua extract can achieve acne efficacy through soothing and oil control,and this function may be achieved by reducing hyaluronic acid degradation,inhibiting inflammatory pathways produced by inflammatory factors TNF-αand IL-6,inhibiting oil secretion,and inhibiting the growth of propionibacterium acnes.
文摘The artemisinin accumulation in the hairy root cultures of Artemisia annua L. was enhanced via a treatment of three fungal elicitors separately ( Verticillium dahliae Kleb., Rhizopus stolonifer (Ehrenb. ex Fr.) Vuill and Colletotrichum dematium (Pers.) Grove). Among these three elicitors, V. dahliae had the highest inducing efficiency, but none of them manifests any noticeable effects on the cell growth of the hairy root cultures. The artemisinin content of the hairy root cultures treated with V. dahliae elicitor was 1.12 mg/g DW, which was 45% higher than the control (0.77 mg/g DW). The results showed that elicitation was dependent on the elicitor concentration, the incubation period and the physiological stage at which the hairy root cultures were treated. In addition, the authors found that for V. dahliae , the optimum concentration was 0.4 mg carbohydrate per millilitre medium, the strongest response of A. annua hairy root cultures to the elicitation was at the late exponential growth stage, and the highest artemisinin content of the hairy root cultures was on the 4th day post treatment.
基金Project of Key Laboratory of Biological Resource Protection and Utilization in Hubei Province(2007025)Open Fund of Hubei Key Laboratory of Biotechnology in Traditional Chinese Medicine in Hubei University(20060201)Project of Hubei Institute for Nationalities~~
文摘[ Objective ] The objective of this study is to explore a rapid and efficient method of extracting genomic DNA from Artemisia abrotanum. [ Method] Three methods of Cutting Method, Liquid Nitrogen Method and Quartz Sand Method based on SDS method were employed to extract Artemisia abrotanum genomlc DNA from tender leaf at seedling stage, tender spike and old leaf at heading stage. The obtained DNAs were detected by absorbance detection, agarose gel and PCR amplification. [ Result ] Cutting Method performed better than the other two methods compared in purity, extracting cycle and cost, accordingly more suitable for PCR amplification. The results also show that young spike is the best material for extracting genomic DNA from Artemisia Annua.
文摘A 1 539 by squalene synthase (AaSQS) cDNA was cloned from a high-yield Artemisia annua L. strain 001 by reverse transcription-polymerise chain reaction (RT-PCR). The amino acid sequence of AaSQS is 70%, 77%, 44% and 39%a identical to that of squalene synthases from Arabidopsis thaliana, tobacco, human and yeast, respectively. The AaSQS genomic DNA has a complex organization containing 14 exons and 13 introns. Full-length or C-terminal truncated cDNA was subcloned into prokaryotic expression vector pET30a and the constructed plasmid was introduced to Escherichia coli strain BL21 (DE3) for induced overexpression. No squalene synthase protein with expected molecular mass was observed in E. cola containing the putative full-length squalene synthase cDNA, however, overexpression in E. coli was achieved by truncating 30 amino acids of hydrophobic region at the carboxy terminus.
基金National Natural Sciences Foundation of China (Nos. 40501072 and 40673067)the Major State Basic Research Develop-ment Program of China (No. 2002CB 412503)the Knowledge In-novation Program of the Institute of Geographic Sciences and Natural Resources Research,CAS "The effect of human activities on regional envi-ronmental quality, the health risk and the environmental remediation"
文摘Biomass and net primary productivity （NPP） are two important parameters in determining ecosystem carbon pool and carbon sequestration. The biomass storage and NPP in desert shrubland of Artemisia ordosica on Ordos Plateau were investigated with method of harvesting standard size shrub in the growing season （June-October） of 2006. Results indicated that above- and belowground biomass of the same size shrubs showed no significant variation in the growing season （p〉0.1）, but annual biomass varied significantly （p〈 0.01）. In the A. ordosica community, shrub biomass storage was 699.76-1246.40 g.m^-2 and annual aboveground NPP was 224.09 g-m^-2·a^-1. Moreover, shrub biomass and NPP were closely related with shrub dimensions （cover and height） and could be well predicted by shrub volume using power regression.
文摘The oligosaccharide elicitor from the mycelial wall of an endophytic Colletotrichum sp. B501 promoted the production of artemisinin in Artemisia annua L. hairy root culture. When hairy roots of 22-day-old cultures (later growth phase) were exposed to the elicitor (20 mg/L) for 4 d, the maximum content of artemisinin reached 1.15 mg/g, a 64.29% increment over the control. The electron X-ray microanalysis disclosed the rapid accumulation of Ca 2+ in the elicited cortical cells of hairy root. The electronic microscope observation revealed the high electron density area in vacuole of elicited cells. During the first day of elicitation the peroxidase activity of hairy roots was improved sharply. Some cellular morphological changes including cell shrinkage, condensation of cytoplasm and nuclear fragmentation, coincident with the appearance of DNA ladders, were observed after the third day of elicitation. It was suggested that the oligosaccharide elicitor triggered the programmed cell death, which may provide the substance or chemical signal for artemisinin biosynthesis.
文摘A 1 886 bp full-length sesquiterpene synthase (AaSES) cDNA was cloned front a high-yield Artemisia annua L. strain 001 by a rapid amplification of cDNA end (RACE) strategy. AaSES is 59% identical to Artemisia cyclase cDNA clone cASC125, 50% identical to epi-cedrol synthase from A. annua , 48% identical to amorpha-4, 11-diene synthase from A. annua, 39% identical to the 5-epi-aristolechene synthase from tabacco, 38 % identical to vetispiradiene synthase front H. muticus, 41 % identical to the, delta-cadinene synthase from cotton. The coding region of the cDNA was inserted into a procaryotic expression vector pET-30a and overexpressed in E. coli BL21 ( DE3). The cyclase proteins extracted front bacterial culture were found largely in an insoluble protein fraction. AaSES expresses in leaves, stems a-rid flowers, not in roots as indicated by Northern blotting analysis.
