A method for in vitro culture and rapid propagation of Chirita ophio- pogoides was developed using leaves as explants in this study, The results indicat- ed that the medium MS+6-BA 0.1 mg/L+NAA 0.1 mg/L was suitable...A method for in vitro culture and rapid propagation of Chirita ophio- pogoides was developed using leaves as explants in this study, The results indicat- ed that the medium MS+6-BA 0.1 mg/L+NAA 0.1 mg/L was suitable for bud induc- tion and seedling regeneration from leaves in primary culture. The media MS+0.5 mg/L 6-BA+0,1 mg/L NAA+10% banana+5% potato and MS+0.5 mg/L 6-BA+0.5 mg/L NAA+2% banana were very suitable for callus multiplication and seedling hardening in subculture, and the proliferation coefficients were 7,9 and 5.6 per 60 d respec- tively. The optimal rooting medium was MS and the rooting rate was 100% on day 30 of culture. The rooted plantlets of C. ophiopogoides were transplanted in green- house with humus soil and 92.5% survived. Theoretically, using the rapid propaga- tion system, about 20 176 seedlings can be reproduced from a sterile plantlet in a year.展开更多
This paper looks back to the development of plant tissue culture in China in the last century. Since 1934, tissue culture studies in China has kept up with the international development in the fields. Progress has bee...This paper looks back to the development of plant tissue culture in China in the last century. Since 1934, tissue culture studies in China has kept up with the international development in the fields. Progress has been made by Chinese in nearly every branches of tissue culture, including in vitro organogenesis, shoot tip culture, anther culture, ovary culture, endosperm culture, protoplast culture as well as mass cell culture. On the basis of reviewing the articles written by Chinese on plant tissue culture, the internationally recognized contributions are specially mentioned. The applications of plant tissue culture to agriculture and industry in China are also introduced.展开更多
Plasmid vector is increasingly applied to gene therapy or gene vaccine. The production of plasmid pCMV-AP3 for cancer gene therapy was conducted in a modified MBL medium using a recombinant E. coli BL21 system. The ef...Plasmid vector is increasingly applied to gene therapy or gene vaccine. The production of plasmid pCMV-AP3 for cancer gene therapy was conducted in a modified MBL medium using a recombinant E. coli BL21 system. The effects of different MMBL components on plasmid yield, cell mass and specific plasmid DNA productivity were evaluated on shake-flask scale. The results showed that glucose was the optimal carbon source. High plasmid yield (58.3 mg/L) was obtained when 5.0 g/L glucose was added to MMBL. Glycerol could be chosen as a complementary carbon source because of the highest specific plasmid pro- ductivity (37.9 mg DNA/g DCW). After tests of different levels of nitrogen source and inorganic phosphate, a modified MMBL medium was formulated for optimal plasmid production. Further study showed that the initial acetate addition (less than 4.0 g/L) in MMBL improved plasmid production significantly, although it inhibited cell growth. The results will be useful for large-scale plasmid production using recombinant E. coli system.展开更多
Young embryos of rice (Oryza saliva L. subsp. japonica var. Guo-xiang No.l) were cultured on MS agar medium(2,4-D 2 mg/l). Calli were formed and subcultured on N6 agar medium (2,4-D 2 mg/l). After selection, the small...Young embryos of rice (Oryza saliva L. subsp. japonica var. Guo-xiang No.l) were cultured on MS agar medium(2,4-D 2 mg/l). Calli were formed and subcultured on N6 agar medium (2,4-D 2 mg/l). After selection, the small, grainy and pale yellowish cell clusters with dense cytoplasm were used in protoplast preparation. Isolated protoplasts were cultured in N6 medium (2,4-D 1 mg/l, 6-BA 0.2 mg/l)1 with agarose block culture method. The protoplasts grew, divided and formed calli. After inducing differentiation, the regenerated mature plants were obtained.展开更多
An efficient protocol for plant regeneration from protoplasts of hydroxyproline(HYP)resistant cell line of Onoblychis viciaefolia was established. In SH medium supplemented with 1 mg/L 2, 4-dichlorophenoxy-acetic acid...An efficient protocol for plant regeneration from protoplasts of hydroxyproline(HYP)resistant cell line of Onoblychis viciaefolia was established. In SH medium supplemented with 1 mg/L 2, 4-dichlorophenoxy-acetic acid (2,4-D), 0.5 mg/L kinetin (KT) and 0.2 mg/L naphthalene acetic acid (NAA), the division frequency of protoplastderived cells reached uP to over 60 %, and microcalli were obtained in 5-6 wk. Upon transferring them on agar solidified MS medium plus 2 mg/L indole-3-acetic acid (IAA), shoots were induced. After cultivating them on MS medium with or without IAA, roots were regenerated.Chromosome number of all protoplast-regenerated plants examined were normal (2n=28). The protoplast-derived calli and plants grew vigorously on the medium containing 10 mmol/L HYP.展开更多
A versatile peroxidase (VP-Peco60-7 ) was generated and purified from the liquid culture of Pleurotus eryngii. The purification procedure included ammonium sulfate precipitation, ion exchange chromatography, and gel c...A versatile peroxidase (VP-Peco60-7 ) was generated and purified from the liquid culture of Pleurotus eryngii. The purification procedure included ammonium sulfate precipitation, ion exchange chromatography, and gel chromatography. The molecular weight and isoelectric point (pI) of VP-Peco60-7 were determined to be approxi-mately 40 kDa and 4.1, respectively. By N-terminal sequence determination and peptide mapping analysis, VP-Peco60-7 was found to be similar to the versatile peroxidase isoenzyme VPL1, which was previously isolated from liquid cultures of the same species. However, the molecular weight and pI of VP-Peco60-7 were different from those of versatile peroxidases of liquid cultures, implying that the VP-Peco60-7 in this study is of a novel type. With 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as a substrate, the maximal enzyme activity was obtained at 50 °C and pH 3.0. The catalysis of ABTS by VP-Peco60-7 was expressed by the Michaelis-Menten equa-tion. At 50 °C and pH 3.0, the maximum velocity (V max ) was 188.68 U·mg-1 and the michaelis constant (K m ) was 203.09 μmol·L-1 .展开更多
Protoplast isolation was relevant for gene manipulation in U lva, and universal protocols have been proposed based on evaluation for various wildly collected species. However, only clonal laboratory cultures were prac...Protoplast isolation was relevant for gene manipulation in U lva, and universal protocols have been proposed based on evaluation for various wildly collected species. However, only clonal laboratory cultures were practical for genetic transformation, and whether applicability of such universal protocol existed for these artificial cultures has never been investigated. In this research, samples in different physiological states or developmental stages were tested in U. prolifera. The results proved that the protoplast yields were strongly dependent on the characteristics of samples. Neither F_v/F_m value nor chlorophyll content exhibited an ideal correlation with the protoplast yields. Alternatively, specific growth rate, coupled with developmental stage, could serve as an ef fective combined index to determine the right time for protoplast isolation. According to this instruction, here we reported the highest yields of protoplast((31.5±1.9)×10~6 cells/g f. wt.) in U. prolifera, following comparison between protocols, and further optimizations on enzyme content, incubation period, starting biomass and pretreatment. This specified protocol for artificially cultured clonal samples could meet the need for protoplast-mediated genetic transformation in U. prolifera.展开更多
Twelve isolates of Curvularia lunata and six related species from maize or other host plants are examined for the analysis of polyacrylamide gel electrophoresis(SDS PAGE) patterns of their soluble proteins. Difference...Twelve isolates of Curvularia lunata and six related species from maize or other host plants are examined for the analysis of polyacrylamide gel electrophoresis(SDS PAGE) patterns of their soluble proteins. Differences exist significantly among different species and the same species. There is a special protein band for Curvularia at relative mobility value 0.177 (Rf 0.177) and a special protein band for C. lunata at Rf 0.225. Two kinds of primary antibodies to C. lunata are used to indirect ELISA and Avidin Biotin peroxidase Complex (ABC) immunoassay to evaluate their detecting sensitivity and specificity. The sensitivity of ABC immuno assay is higher than indirect ELISA. APAbs to C. lunata is special to C. lunata.展开更多
The matrix metalloproteinase (MMP) stromelysin-3 (ST3) has long been implicated to play an important role in extracellular matrix (ECM) remodeling and cell fate determination during normal and pathological processes. ...The matrix metalloproteinase (MMP) stromelysin-3 (ST3) has long been implicated to play an important role in extracellular matrix (ECM) remodeling and cell fate determination during normal and pathological processes. However like other MMPs, the molecular basis of ST3 function in vivo remains unclear due to the lack of information on its physiological substrates. Furthermore, ST3 has only weak activities toward all tested ECM proteins. Using thyroid hormone-dependent Xenopus laevis metamorphosis as a model, we demonstrated previously that ST3 is important for apoptosis and tissue morphogenesis during intestinal remodeling. Here, we used yeast two-hybrid screen with mRNAs from metamorphosing tadpoles to identify potential substrate of ST3 during development. We thus isolated the 37 kd laminin receptor precursor (LR). We showed that LR binds to ST3 in vitro and can be cleaved by ST3 at two sites distinct from where other MMPs cleave. Through peptide sequencing, we determined that the two cleavage sites are in the extracellular domain between the transmembrane domain and laminin binding sequence. Furthermore, we demon strated that these cleavage sites are conserved in human LR. These results together with high levels of human LR and ST3 expression in carcinomas suggest that LR is a likely in vivo substrate of ST3 and that its cleavage by ST3 may alter cell-extracellular matrix interaction, thus, playing a role in mediating the effects of ST3 on cell fate and behavior ob- served during development and pathogenesis.展开更多
Plasma membrane of plant cells is surrounded by cellulose wall and adjacent cells are joined together by a thick pectin rich matrix. Separation of plant cells and removal of the cell wall experimentally, by either a m...Plasma membrane of plant cells is surrounded by cellulose wall and adjacent cells are joined together by a thick pectin rich matrix. Separation of plant cells and removal of the cell wall experimentally, by either a mechanical or an enzymatic process, results in the production ofprotoplast. Protoplasts are useful tools to study the uptake and transport ofmacromolecules and production of somatic hybrids. Protoplasts can be obtained from all types of actively growing young and healthy tissues. The most convenient and widely used source of plant protoplasts is leaf. Juvenile seedling tissues, cotyledons are other alternative tissues most frequently used for protoplasts isolation. All the environmental and genotypic factors, which affect the cell wall thickenings and compactness indirectly, influence the number of protoplasts recovered. Protoplasts are isolated by two methods, mechanical and enzymatic. The enzyme mixture solution of celluiose/macerozyme is used to digest the cell wall. The critical factors affecting the obtaning ofprotoplasts are the kinds of cell wall degrading enzymes, the physiological state of plant leaves, the type of osmotic stabilizers and the composition of reaction solution. With the improvement of technique and enzyme combination rate, the yield of collected protoplasts will be increased higher.展开更多
Basic courses are responsible for the cultivation of integrative qualities, which is a guarantee of the long-term sustainable development for the students.However, they are now challenged by the specialized courses in...Basic courses are responsible for the cultivation of integrative qualities, which is a guarantee of the long-term sustainable development for the students.However, they are now challenged by the specialized courses in Chinese colleges.This essay first analyzes the current situation of the provision of basic courses in higher vocational colleges of China, then expounds the requirements of qualities cultivation of enterprises, and at last centers on the basic courses system construction in higher vocational colleges on orientation of qualities cultivation.展开更多
The gene ble from Streptoalloteichus hindustanus is widely used as a selective antibiotic marker. It can control the phleomycin resistance, and significantly increase the tolerance of hosts to zeocin. The unicellular ...The gene ble from Streptoalloteichus hindustanus is widely used as a selective antibiotic marker. It can control the phleomycin resistance, and significantly increase the tolerance of hosts to zeocin. The unicellular marine microalga Nannochloropsis oculata is extremely sensitive to zeocin. We selected ble as the selective marker for the genetic transformation of N. oculata. After the algal cells at a density of 2× 10^7 cells mL-1 was digested with 4% hemicellulase and 2% driselase for 1 h, the protoplasts accounted for 90% of the total. The ble was placed at the downstream of promoter HSP70A-RUBS2 isolated from Chlamydomonas reinhardtii, yielding a recombinant expression construct pMS 188. The construct was transferred into the protoplasts through electroporation (1 kV, 15 μS). The transformed protoplasts were cultured in fresh f/2 liquid medium, and selected on solid f/2 medium supplemented with 500 ng mL-t zeoein. The PCR result proved that ble existed in the transformants. Three transformants had been cultured for at least 5 generations without losing ble. Southern blotting analysis showed that the ble has been integrated into the genome of N. oculata. The ble will serve as a new dominant selective marker in genetic engineering N. oculata.展开更多
Global warming that triggered the climate change is largely due to increased CO2 concentrations. Utilization of Chlorella sp. to reduce CO2 gas is a promising potential. Chlorella can efficiently reduce CO2 and easily...Global warming that triggered the climate change is largely due to increased CO2 concentrations. Utilization of Chlorella sp. to reduce CO2 gas is a promising potential. Chlorella can efficiently reduce CO2 and easily be adapted into the photobioreactor system engineering. In this research, the type of microalgae which is used is Chlorella vulgaris in Benneck medium. The system of used reactor is mid-scale bubble column photobioreactor flowed by air which contains 5% CO2. Chlorella vulgaris biomass production will be increased by adjusting the cell density in the photobioreactor. These arrangements will be implemented through a continuous treatment of cell entrapment. The arrangement of cell density in continuous reactor has been proven to increase production of Chlorella vulgaris biomass about 1.25 times more than cultivation without arrangement of cell density by using the same number of inoculums. The results also have shown that the average rate of CO2 fixation and Carbon Transfer Rate (CTR) are obtained at cell entrapment condition about 17 times larger. Continuous cellular entrapment method is very potential to be developed as a method for the production of biomass. Lipids and carotene that have been produced from Ch. vulgaris respectively are 18.24% and 9.42 ppm.展开更多
Military talents are those who have higher culture and scientific quality, much strong innovation consciousness and thinking ability. The overall objective of military talent training is to cultivate the comprehensive...Military talents are those who have higher culture and scientific quality, much strong innovation consciousness and thinking ability. The overall objective of military talent training is to cultivate the comprehensive-quality military personnel that meet the requirements of military modernization and preparations for military struggle. In this paper, we construct the military talent training objectives model, and on this basis, we propose the innovative military talent training mode, from the perspective of curriculum content system and talent quality assurance system.展开更多
Objective: We investigated the effects of intermittent negative pressure on osteogenesis in human bone marrowderived stroma cells (BMSCs) in vitro. Methods: BMSCs were isolated from adult marrow donated by a hip o...Objective: We investigated the effects of intermittent negative pressure on osteogenesis in human bone marrowderived stroma cells (BMSCs) in vitro. Methods: BMSCs were isolated from adult marrow donated by a hip osteoarthritis patient with prosthetic replacement and cultured in vitro. The third passage cells were divided into negative pressure treatment group and control group. The treatment group was induced by negative pressure intermittently (pressure: 50 kPa, 30 min/times, and twice daily). The control was cultured in conventional condition. The osteogenesis of BMSCs was examined by phase-contrast mi- croscopy, the determination of alkaline phosphatase (ALP) activities, and the immunohistochemistry of collagen type 1. The mRNA expressions of osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) in BMSCs were analyzed by real-time polymerase chain reaction (PCR). Results: BMSCs showed a typical appearance of osteoblast after 2 weeks of induction by intermittent negative pressure, the activity of ALP increased significantly, and the expression of collagen type I was positive. In the treatment group, the mRNA expression of OPG increased significantly (P〈0.05) and the mRNA expression of OPGL decreased significantly (P〈0.05) after 2 weeks, compared with the control. Conclusion: Intermittent negative pressure could promote osteogenesis in human BMSCs in vitro.展开更多
基金Supported by National Natural Science Foundation of China(31160055)Key Science and Technology Research and Development Program of Guangxi(Gui Ke Gong0992003B-31)~~
文摘A method for in vitro culture and rapid propagation of Chirita ophio- pogoides was developed using leaves as explants in this study, The results indicat- ed that the medium MS+6-BA 0.1 mg/L+NAA 0.1 mg/L was suitable for bud induc- tion and seedling regeneration from leaves in primary culture. The media MS+0.5 mg/L 6-BA+0,1 mg/L NAA+10% banana+5% potato and MS+0.5 mg/L 6-BA+0.5 mg/L NAA+2% banana were very suitable for callus multiplication and seedling hardening in subculture, and the proliferation coefficients were 7,9 and 5.6 per 60 d respec- tively. The optimal rooting medium was MS and the rooting rate was 100% on day 30 of culture. The rooted plantlets of C. ophiopogoides were transplanted in green- house with humus soil and 92.5% survived. Theoretically, using the rapid propaga- tion system, about 20 176 seedlings can be reproduced from a sterile plantlet in a year.
文摘This paper looks back to the development of plant tissue culture in China in the last century. Since 1934, tissue culture studies in China has kept up with the international development in the fields. Progress has been made by Chinese in nearly every branches of tissue culture, including in vitro organogenesis, shoot tip culture, anther culture, ovary culture, endosperm culture, protoplast culture as well as mass cell culture. On the basis of reviewing the articles written by Chinese on plant tissue culture, the internationally recognized contributions are specially mentioned. The applications of plant tissue culture to agriculture and industry in China are also introduced.
文摘Plasmid vector is increasingly applied to gene therapy or gene vaccine. The production of plasmid pCMV-AP3 for cancer gene therapy was conducted in a modified MBL medium using a recombinant E. coli BL21 system. The effects of different MMBL components on plasmid yield, cell mass and specific plasmid DNA productivity were evaluated on shake-flask scale. The results showed that glucose was the optimal carbon source. High plasmid yield (58.3 mg/L) was obtained when 5.0 g/L glucose was added to MMBL. Glycerol could be chosen as a complementary carbon source because of the highest specific plasmid pro- ductivity (37.9 mg DNA/g DCW). After tests of different levels of nitrogen source and inorganic phosphate, a modified MMBL medium was formulated for optimal plasmid production. Further study showed that the initial acetate addition (less than 4.0 g/L) in MMBL improved plasmid production significantly, although it inhibited cell growth. The results will be useful for large-scale plasmid production using recombinant E. coli system.
文摘Young embryos of rice (Oryza saliva L. subsp. japonica var. Guo-xiang No.l) were cultured on MS agar medium(2,4-D 2 mg/l). Calli were formed and subcultured on N6 agar medium (2,4-D 2 mg/l). After selection, the small, grainy and pale yellowish cell clusters with dense cytoplasm were used in protoplast preparation. Isolated protoplasts were cultured in N6 medium (2,4-D 1 mg/l, 6-BA 0.2 mg/l)1 with agarose block culture method. The protoplasts grew, divided and formed calli. After inducing differentiation, the regenerated mature plants were obtained.
文摘An efficient protocol for plant regeneration from protoplasts of hydroxyproline(HYP)resistant cell line of Onoblychis viciaefolia was established. In SH medium supplemented with 1 mg/L 2, 4-dichlorophenoxy-acetic acid (2,4-D), 0.5 mg/L kinetin (KT) and 0.2 mg/L naphthalene acetic acid (NAA), the division frequency of protoplastderived cells reached uP to over 60 %, and microcalli were obtained in 5-6 wk. Upon transferring them on agar solidified MS medium plus 2 mg/L indole-3-acetic acid (IAA), shoots were induced. After cultivating them on MS medium with or without IAA, roots were regenerated.Chromosome number of all protoplast-regenerated plants examined were normal (2n=28). The protoplast-derived calli and plants grew vigorously on the medium containing 10 mmol/L HYP.
基金Supported by the Special Funds for Major State Basic Research Program of China (2007CB707805) the Natural Science Foundation of Zhejiang Province (Y505334)
文摘A versatile peroxidase (VP-Peco60-7 ) was generated and purified from the liquid culture of Pleurotus eryngii. The purification procedure included ammonium sulfate precipitation, ion exchange chromatography, and gel chromatography. The molecular weight and isoelectric point (pI) of VP-Peco60-7 were determined to be approxi-mately 40 kDa and 4.1, respectively. By N-terminal sequence determination and peptide mapping analysis, VP-Peco60-7 was found to be similar to the versatile peroxidase isoenzyme VPL1, which was previously isolated from liquid cultures of the same species. However, the molecular weight and pI of VP-Peco60-7 were different from those of versatile peroxidases of liquid cultures, implying that the VP-Peco60-7 in this study is of a novel type. With 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as a substrate, the maximal enzyme activity was obtained at 50 °C and pH 3.0. The catalysis of ABTS by VP-Peco60-7 was expressed by the Michaelis-Menten equa-tion. At 50 °C and pH 3.0, the maximum velocity (V max ) was 188.68 U·mg-1 and the michaelis constant (K m ) was 203.09 μmol·L-1 .
基金Supported by the National Natural Science Foundation of China(No.41776153)the Scientific and Technological Innovation Project financially supported by Qingdao National Laboratory for Marine Science and Technology(No.2016ASKJ02-1)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA11020304)the Postdoctoral Application Research Program funded by Qingdao(No.2016189)
文摘Protoplast isolation was relevant for gene manipulation in U lva, and universal protocols have been proposed based on evaluation for various wildly collected species. However, only clonal laboratory cultures were practical for genetic transformation, and whether applicability of such universal protocol existed for these artificial cultures has never been investigated. In this research, samples in different physiological states or developmental stages were tested in U. prolifera. The results proved that the protoplast yields were strongly dependent on the characteristics of samples. Neither F_v/F_m value nor chlorophyll content exhibited an ideal correlation with the protoplast yields. Alternatively, specific growth rate, coupled with developmental stage, could serve as an ef fective combined index to determine the right time for protoplast isolation. According to this instruction, here we reported the highest yields of protoplast((31.5±1.9)×10~6 cells/g f. wt.) in U. prolifera, following comparison between protocols, and further optimizations on enzyme content, incubation period, starting biomass and pretreatment. This specified protocol for artificially cultured clonal samples could meet the need for protoplast-mediated genetic transformation in U. prolifera.
文摘Twelve isolates of Curvularia lunata and six related species from maize or other host plants are examined for the analysis of polyacrylamide gel electrophoresis(SDS PAGE) patterns of their soluble proteins. Differences exist significantly among different species and the same species. There is a special protein band for Curvularia at relative mobility value 0.177 (Rf 0.177) and a special protein band for C. lunata at Rf 0.225. Two kinds of primary antibodies to C. lunata are used to indirect ELISA and Avidin Biotin peroxidase Complex (ABC) immunoassay to evaluate their detecting sensitivity and specificity. The sensitivity of ABC immuno assay is higher than indirect ELISA. APAbs to C. lunata is special to C. lunata.
文摘The matrix metalloproteinase (MMP) stromelysin-3 (ST3) has long been implicated to play an important role in extracellular matrix (ECM) remodeling and cell fate determination during normal and pathological processes. However like other MMPs, the molecular basis of ST3 function in vivo remains unclear due to the lack of information on its physiological substrates. Furthermore, ST3 has only weak activities toward all tested ECM proteins. Using thyroid hormone-dependent Xenopus laevis metamorphosis as a model, we demonstrated previously that ST3 is important for apoptosis and tissue morphogenesis during intestinal remodeling. Here, we used yeast two-hybrid screen with mRNAs from metamorphosing tadpoles to identify potential substrate of ST3 during development. We thus isolated the 37 kd laminin receptor precursor (LR). We showed that LR binds to ST3 in vitro and can be cleaved by ST3 at two sites distinct from where other MMPs cleave. Through peptide sequencing, we determined that the two cleavage sites are in the extracellular domain between the transmembrane domain and laminin binding sequence. Furthermore, we demon strated that these cleavage sites are conserved in human LR. These results together with high levels of human LR and ST3 expression in carcinomas suggest that LR is a likely in vivo substrate of ST3 and that its cleavage by ST3 may alter cell-extracellular matrix interaction, thus, playing a role in mediating the effects of ST3 on cell fate and behavior ob- served during development and pathogenesis.
文摘Plasma membrane of plant cells is surrounded by cellulose wall and adjacent cells are joined together by a thick pectin rich matrix. Separation of plant cells and removal of the cell wall experimentally, by either a mechanical or an enzymatic process, results in the production ofprotoplast. Protoplasts are useful tools to study the uptake and transport ofmacromolecules and production of somatic hybrids. Protoplasts can be obtained from all types of actively growing young and healthy tissues. The most convenient and widely used source of plant protoplasts is leaf. Juvenile seedling tissues, cotyledons are other alternative tissues most frequently used for protoplasts isolation. All the environmental and genotypic factors, which affect the cell wall thickenings and compactness indirectly, influence the number of protoplasts recovered. Protoplasts are isolated by two methods, mechanical and enzymatic. The enzyme mixture solution of celluiose/macerozyme is used to digest the cell wall. The critical factors affecting the obtaning ofprotoplasts are the kinds of cell wall degrading enzymes, the physiological state of plant leaves, the type of osmotic stabilizers and the composition of reaction solution. With the improvement of technique and enzyme combination rate, the yield of collected protoplasts will be increased higher.
文摘Basic courses are responsible for the cultivation of integrative qualities, which is a guarantee of the long-term sustainable development for the students.However, they are now challenged by the specialized courses in Chinese colleges.This essay first analyzes the current situation of the provision of basic courses in higher vocational colleges of China, then expounds the requirements of qualities cultivation of enterprises, and at last centers on the basic courses system construction in higher vocational colleges on orientation of qualities cultivation.
基金supported by the Provincial Natural Science Foundation of Shandong Province,China (2013ZRB14055)and the National Natural Science Foundation of China (Grant No.31372518)
文摘The gene ble from Streptoalloteichus hindustanus is widely used as a selective antibiotic marker. It can control the phleomycin resistance, and significantly increase the tolerance of hosts to zeocin. The unicellular marine microalga Nannochloropsis oculata is extremely sensitive to zeocin. We selected ble as the selective marker for the genetic transformation of N. oculata. After the algal cells at a density of 2× 10^7 cells mL-1 was digested with 4% hemicellulase and 2% driselase for 1 h, the protoplasts accounted for 90% of the total. The ble was placed at the downstream of promoter HSP70A-RUBS2 isolated from Chlamydomonas reinhardtii, yielding a recombinant expression construct pMS 188. The construct was transferred into the protoplasts through electroporation (1 kV, 15 μS). The transformed protoplasts were cultured in fresh f/2 liquid medium, and selected on solid f/2 medium supplemented with 500 ng mL-t zeoein. The PCR result proved that ble existed in the transformants. Three transformants had been cultured for at least 5 generations without losing ble. Southern blotting analysis showed that the ble has been integrated into the genome of N. oculata. The ble will serve as a new dominant selective marker in genetic engineering N. oculata.
文摘Global warming that triggered the climate change is largely due to increased CO2 concentrations. Utilization of Chlorella sp. to reduce CO2 gas is a promising potential. Chlorella can efficiently reduce CO2 and easily be adapted into the photobioreactor system engineering. In this research, the type of microalgae which is used is Chlorella vulgaris in Benneck medium. The system of used reactor is mid-scale bubble column photobioreactor flowed by air which contains 5% CO2. Chlorella vulgaris biomass production will be increased by adjusting the cell density in the photobioreactor. These arrangements will be implemented through a continuous treatment of cell entrapment. The arrangement of cell density in continuous reactor has been proven to increase production of Chlorella vulgaris biomass about 1.25 times more than cultivation without arrangement of cell density by using the same number of inoculums. The results also have shown that the average rate of CO2 fixation and Carbon Transfer Rate (CTR) are obtained at cell entrapment condition about 17 times larger. Continuous cellular entrapment method is very potential to be developed as a method for the production of biomass. Lipids and carotene that have been produced from Ch. vulgaris respectively are 18.24% and 9.42 ppm.
文摘Military talents are those who have higher culture and scientific quality, much strong innovation consciousness and thinking ability. The overall objective of military talent training is to cultivate the comprehensive-quality military personnel that meet the requirements of military modernization and preparations for military struggle. In this paper, we construct the military talent training objectives model, and on this basis, we propose the innovative military talent training mode, from the perspective of curriculum content system and talent quality assurance system.
基金Project (No. 20070421123) supported by the Postdoctoral Science Foundation of China
文摘Objective: We investigated the effects of intermittent negative pressure on osteogenesis in human bone marrowderived stroma cells (BMSCs) in vitro. Methods: BMSCs were isolated from adult marrow donated by a hip osteoarthritis patient with prosthetic replacement and cultured in vitro. The third passage cells were divided into negative pressure treatment group and control group. The treatment group was induced by negative pressure intermittently (pressure: 50 kPa, 30 min/times, and twice daily). The control was cultured in conventional condition. The osteogenesis of BMSCs was examined by phase-contrast mi- croscopy, the determination of alkaline phosphatase (ALP) activities, and the immunohistochemistry of collagen type 1. The mRNA expressions of osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) in BMSCs were analyzed by real-time polymerase chain reaction (PCR). Results: BMSCs showed a typical appearance of osteoblast after 2 weeks of induction by intermittent negative pressure, the activity of ALP increased significantly, and the expression of collagen type I was positive. In the treatment group, the mRNA expression of OPG increased significantly (P〈0.05) and the mRNA expression of OPGL decreased significantly (P〈0.05) after 2 weeks, compared with the control. Conclusion: Intermittent negative pressure could promote osteogenesis in human BMSCs in vitro.