We have developed a 'double T-DNA' binary vector system for generating selectable marker-free transgenic plants by Agrobacterium-mediated transformation. The 'double T-DNA' binary vector pDLBRBbarm whi...We have developed a 'double T-DNA' binary vector system for generating selectable marker-free transgenic plants by Agrobacterium-mediated transformation. The 'double T-DNA' binary vector pDLBRBbarm which carried two independent T-DNAs, one containing a selectable marker neomycin phosphotransferase (nptII) gene and the other a bargene, was constructed. Transgenic tobacco (Nicotiana tabacum L.) plants were then produced by Agrobacterium-mediated transformation with this vector. Frequency of the primary transformants co-integrated with npt II gene and bar gene was 59.2%. Segregation of two T-DNA regions was found in 3 out of 4 T-1 lines from co-transformed T-0 plants with nptII and bar PPT-resistant and kanamycin-sensitive plants were in approximate 19.5% of the T-1 plants. The result indicated that this 'double T-DNA' vector system could be a workable approach to generate transgenic plants free from selectable marker genes. Co-transformation of nptII gene and bar gene to plants with mixtures of Agrobacterium tumefaciens strains containing single T-DNA vectors was also tested. Frequency of co-transformed plants was 20.0%-47.7% and relatively low as compared with that of 'double T-DNA' vector system.展开更多
As one of the active compounds derived from Traditional Chinese Medicine,Celastrol(CSL)had cytotoxicity for human leukemia cancer cells K562 and its multidrug-resistant cell line K562/A02.Here,we introduced cysteamine...As one of the active compounds derived from Traditional Chinese Medicine,Celastrol(CSL)had cytotoxicity for human leukemia cancer cells K562 and its multidrug-resistant cell line K562/A02.Here,we introduced cysteamine-modified CdTe QDs as the labeling and drug carrier into CSL research and found that the self-assembly and conjugation of anticancer molecular CSL with the Cys-CdTe QDs could significantly increase the drug’s cytotoxicity for K562 cells.More important,these CSL-Cys-CdTe nanocomposites could overcome the multidrug resistance of K562/A02 cells and efficiently inhibit the cancer cell proliferation by realizing the pH-sensitive responsive release of CSL to cancer cells.The enhanced cytotoxicity was caused by the increase of the G2/M phase arrest for K562/A02 cells as well as for K562 cells.Cys-CdTe QDs can readily bind on the cell plasma membranes and be internalized into cancer cells to trace and detect human leukemia cancer cells in real time.In addition,these Cys-CdTe QDs can facilitate the inhibition of the multidrug resistance of K562/A02 cells and readily induce apoptosis.As a good photosensitizer for the therapy,labeling,and tracing of cancer cells,the combination of CSL with Cys-CdTe QDs can optimize the use of and a new potential therapy method for CSL and yield new tools to explore the mechanisms of active compounds from Traditional Chinese Medicine.展开更多
文摘We have developed a 'double T-DNA' binary vector system for generating selectable marker-free transgenic plants by Agrobacterium-mediated transformation. The 'double T-DNA' binary vector pDLBRBbarm which carried two independent T-DNAs, one containing a selectable marker neomycin phosphotransferase (nptII) gene and the other a bargene, was constructed. Transgenic tobacco (Nicotiana tabacum L.) plants were then produced by Agrobacterium-mediated transformation with this vector. Frequency of the primary transformants co-integrated with npt II gene and bar gene was 59.2%. Segregation of two T-DNA regions was found in 3 out of 4 T-1 lines from co-transformed T-0 plants with nptII and bar PPT-resistant and kanamycin-sensitive plants were in approximate 19.5% of the T-1 plants. The result indicated that this 'double T-DNA' vector system could be a workable approach to generate transgenic plants free from selectable marker genes. Co-transformation of nptII gene and bar gene to plants with mixtures of Agrobacterium tumefaciens strains containing single T-DNA vectors was also tested. Frequency of co-transformed plants was 20.0%-47.7% and relatively low as compared with that of 'double T-DNA' vector system.
基金supported by the National Science Foundation for Distinguished Young Scholars of China (81325011)the National Basic Research Program of China (2010CB732404)+5 种基金the National Natural Science Foundation of China (21175020)the Natural Science Foundation of Jiangsu Province University (13KJB310015)the Open Research Fund of the State Key Laboratory of Bioelectronics,Southeast Universitythe Science and Technology Foundation of Nantong City (BK2013045)the Startup Foundation for Introduced Talents at Nantong Universitysupport by the United States NSF-CREST program (HRD0932421)
文摘As one of the active compounds derived from Traditional Chinese Medicine,Celastrol(CSL)had cytotoxicity for human leukemia cancer cells K562 and its multidrug-resistant cell line K562/A02.Here,we introduced cysteamine-modified CdTe QDs as the labeling and drug carrier into CSL research and found that the self-assembly and conjugation of anticancer molecular CSL with the Cys-CdTe QDs could significantly increase the drug’s cytotoxicity for K562 cells.More important,these CSL-Cys-CdTe nanocomposites could overcome the multidrug resistance of K562/A02 cells and efficiently inhibit the cancer cell proliferation by realizing the pH-sensitive responsive release of CSL to cancer cells.The enhanced cytotoxicity was caused by the increase of the G2/M phase arrest for K562/A02 cells as well as for K562 cells.Cys-CdTe QDs can readily bind on the cell plasma membranes and be internalized into cancer cells to trace and detect human leukemia cancer cells in real time.In addition,these Cys-CdTe QDs can facilitate the inhibition of the multidrug resistance of K562/A02 cells and readily induce apoptosis.As a good photosensitizer for the therapy,labeling,and tracing of cancer cells,the combination of CSL with Cys-CdTe QDs can optimize the use of and a new potential therapy method for CSL and yield new tools to explore the mechanisms of active compounds from Traditional Chinese Medicine.
