Agrobacterium tumefaciens strain LBA 4404 carrying pBI121 plasmid was used to transform mature zygotic embryos of three genotypes (E-Hb, E-Ma, and E-Mc) of loblolly pine. The results demonstrated that the expression f...Agrobacterium tumefaciens strain LBA 4404 carrying pBI121 plasmid was used to transform mature zygotic embryos of three genotypes (E-Hb, E-Ma, and E-Mc) of loblolly pine. The results demonstrated that the expression frequency of (-glucuronidase reporter gene (GUS) varied among genotypes after mature zygotic embryos were infected with Agrobacterium tumefaciens cultures. The highest frequency (27.8%) of GUS expressing embryos was obtained from genotype E-Mc with mean number of 21.9 blue GUS spots per embryo. Expression of (-glucuronidase reporter gene was observed on cotyledons, hypocotyls, and radicles of transformed mature zygotic embryos, as well as on organogenic callus and regenerated shoots derived from co-cultivated mature zygotic embryos. Nineteen regenerated transgenic plants were obtained from GUS expression and kanamycin resistant calli. The presence and integration of the GUS gene was confirmed by polymerase chain reaction (PCR) and Southern blot analysis. These results suggested that an efficient Agrobacterium tumefaciens-mediated transformation protocol for stable integration of foreign genes into loblolly pine has been developed and that this transformation system could be useful for the future studies on transferring economically important genes to loblolly pine.展开更多
Trehalose synthase gene (TSase) from Grifola frondosa was transferred into sugarcane (Sac-charum hybrid L.) using Agrobacterium-mediated method to improve sugarcane drought-tolerance. The results indicated that embryo...Trehalose synthase gene (TSase) from Grifola frondosa was transferred into sugarcane (Sac-charum hybrid L.) using Agrobacterium-mediated method to improve sugarcane drought-tolerance. The results indicated that embryogenic callus of sugarcane was sensitive to A. tumefaciens EHA105 strain in the transformation system employed. The high frequency PPT-resistant plants were obtained from transformated with 3 weeks callus after incubation, which reached 4.5% on average. The transgenic plants were confirmed by PCR and Southern analysis. Some transgenic plants showed multiple phenotypic alterations and some plants demonstrated improvement tolerance to osmotic stress.展开更多
In order to improve stress tolerances of turf-type tall fescue （Festuca arundinacea Schreb.）, Agrobacterium tumefaciens strain EHA105 carrying plasmid pCMD containing stress tolerance-related CBF1 gene from Arabidop...In order to improve stress tolerances of turf-type tall fescue （Festuca arundinacea Schreb.）, Agrobacterium tumefaciens strain EHA105 carrying plasmid pCMD containing stress tolerance-related CBF1 gene from Arabidopsis thaliana was used to transform mature seeds-derived embryogenic calli of four cultivars. A total of 112 transgenic plants were regenerated from 32 independent lines and verified by histochemical detection of GUS activity, PCR assay and Southern hybridization analysis. The transformation frequency ranged from 0.92 to 2.87% with apparent differences among the cultivars. Stress tolerances of transgenic plants were enhanced, which was shown by the facts that transgenic plants had distinct growth superiority and significantly higher survival rate than non-transformed ones under high salinity and high osmosis stresses, and that relative electronic conductivity of in vitro leaves treated with low and high temoeratures, dehvdration and high salinity stresses was 25-30% lower in transgenic plants than in control plants.In addition,it was observed that growth of transgenic plants was inhibited due to constitutive overexpression of CBF1 gene under normal environmental conditions.展开更多
Glycinebetaine(GB),an osmotic substance,could improve some stress tolerance in plants.CodA gene,originating from bacteria,could translate choline oxidase which stimulates the synthesis of GB in plants.To create lily l...Glycinebetaine(GB),an osmotic substance,could improve some stress tolerance in plants.CodA gene,originating from bacteria,could translate choline oxidase which stimulates the synthesis of GB in plants.To create lily lines resistant to heat,Belladonna lily and Yelloween lily had been transferred CodA gene through Agrobacterium tumefaciens.The bacteria harbored a binary vector carrying the hygromycin phosphotransferase,choline oxidase(CodA)and intron-containingβ-glucuronidase(Gus)genes were co-cultivated with lily bulb scales slides.The result showed that most the bulb scales had developed into bulblets in a regulator-free growth medium,while some expressed the hygromycin-resistance,heat tolerance and Gus gene expression.Among them,one line demonstrated primarily the transcription level expression through reverse transcription polymerase chain reaction(RT-PCR).Moreover,they were tested with the accumulation of GB which was evident that the transferred line had four times of GB volumes higher than that of wild type.The original evidence could open a right approach to enhance stress tolerance in lily plants.展开更多
Genetic transformation is a useful technique to complement conventional breeding in crop improvement. Although carrot has been a model organism for in vitro embryogenesis study, genetic transformation of carrot is sti...Genetic transformation is a useful technique to complement conventional breeding in crop improvement. Although carrot has been a model organism for in vitro embryogenesis study, genetic transformation of carrot is still lengthy and labor intensive. An efficient transformation and detection system is desirable. Direct infection of Agrobacterium to carrot calli has provided an easy way for carrot genetic transformation. To improve the efficiency of antibiotic selection in this method, we report the combined use of an improved green-fluorescent protein, referred to as smGFP, to establish a versatile selection method for carrot callus transformation system. By combining antibiotic selection with the bright fluorescence observed in the callus tissue, we were able to easily identify stable transformants in early stage of the transformation process. In addition to the GFP expression of the callus cells, the transgenic nature of callus cells was confirmed with Southern and Western analysis. We found we can link the simplicity of carrot-callus-cell transformation, early detection of stable transformants with antibiotic selection, visualization of GFP fluorescence, and molecular analysis （Southern and Western） of callus tissue （non-photosynthetic tissue） to provide a more efficient way in identifying stable transformants at early stage of carrot transformation.展开更多
In this study, CryⅠA(b) gene was successfully transferred into the biocontrol fungus Trichoderma har- zianum with an efficiency of 60—180 transformants per 106 spores by using Agrobacterium tumefaciens-mediated tran...In this study, CryⅠA(b) gene was successfully transferred into the biocontrol fungus Trichoderma har- zianum with an efficiency of 60—180 transformants per 106 spores by using Agrobacterium tumefaciens-mediated trans- formation. Putative transformants were analyzed to test the presence of CryⅠA(b) gene by Southern blot. Most trans- formants contained a single T-DNA copy. RT-PCR analysis showed that the CryⅠA(b) gene was transcribed. Antifungal activities and insecticidal activities of the transformants were examined. There was no obvious difference in antifungal activities between the transformants and their wild strains. The modified mortalities of the transformants T1 and T2 were 69.57% and 91.30%, respectively. The tranformation system mediated by A. tumefaciens proved to be a powerful tool for the filamentous fungi transformation and functional genomic study with its high transformation frequency, sim- plicity of T-DNA integration, and genetic stability of transformants.展开更多
The flower’s meristematic characteristic gene AP1 was introduced into Chrysanthemum morifolium cv. ‘Yu Ren Mian’ mediated by Agrobacterium tumefaciens.The factors influencing genetic transformation protocol were st...The flower’s meristematic characteristic gene AP1 was introduced into Chrysanthemum morifolium cv. ‘Yu Ren Mian’ mediated by Agrobacterium tumefaciens.The factors influencing genetic transformation protocol were studied.The results showed that the leaf explants precultured for 2～8 hours or not precultured were best for transformation by A. tumefaciens. The suitable concentration of bacterial and the time for infecting was OD_ 600 0.5 for 10 minutes. Leaves were cocultivated with bacterial at 23～25 ℃ for 2 days,then delayed selection for 3 days. Kan^r plant were selected by increased selective press from 5 mg·L ~ -1 G418 to 7.5 mg5L~ -1 G418 followed by 10 mg5L~ -1 G418. The integration of AP1 gene into C. morifolium ‘Yu Ren Mian’ was confirmed by PCR and Southern blotting.Two of transgenic plants bloomed 15 days earlier than untransformed plants.展开更多
文摘Agrobacterium tumefaciens strain LBA 4404 carrying pBI121 plasmid was used to transform mature zygotic embryos of three genotypes (E-Hb, E-Ma, and E-Mc) of loblolly pine. The results demonstrated that the expression frequency of (-glucuronidase reporter gene (GUS) varied among genotypes after mature zygotic embryos were infected with Agrobacterium tumefaciens cultures. The highest frequency (27.8%) of GUS expressing embryos was obtained from genotype E-Mc with mean number of 21.9 blue GUS spots per embryo. Expression of (-glucuronidase reporter gene was observed on cotyledons, hypocotyls, and radicles of transformed mature zygotic embryos, as well as on organogenic callus and regenerated shoots derived from co-cultivated mature zygotic embryos. Nineteen regenerated transgenic plants were obtained from GUS expression and kanamycin resistant calli. The presence and integration of the GUS gene was confirmed by polymerase chain reaction (PCR) and Southern blot analysis. These results suggested that an efficient Agrobacterium tumefaciens-mediated transformation protocol for stable integration of foreign genes into loblolly pine has been developed and that this transformation system could be useful for the future studies on transferring economically important genes to loblolly pine.
基金This work was supported by the National Natural Science Foundation of China(30160045).
文摘Trehalose synthase gene (TSase) from Grifola frondosa was transferred into sugarcane (Sac-charum hybrid L.) using Agrobacterium-mediated method to improve sugarcane drought-tolerance. The results indicated that embryogenic callus of sugarcane was sensitive to A. tumefaciens EHA105 strain in the transformation system employed. The high frequency PPT-resistant plants were obtained from transformated with 3 weeks callus after incubation, which reached 4.5% on average. The transgenic plants were confirmed by PCR and Southern analysis. Some transgenic plants showed multiple phenotypic alterations and some plants demonstrated improvement tolerance to osmotic stress.
文摘In order to improve stress tolerances of turf-type tall fescue （Festuca arundinacea Schreb.）, Agrobacterium tumefaciens strain EHA105 carrying plasmid pCMD containing stress tolerance-related CBF1 gene from Arabidopsis thaliana was used to transform mature seeds-derived embryogenic calli of four cultivars. A total of 112 transgenic plants were regenerated from 32 independent lines and verified by histochemical detection of GUS activity, PCR assay and Southern hybridization analysis. The transformation frequency ranged from 0.92 to 2.87% with apparent differences among the cultivars. Stress tolerances of transgenic plants were enhanced, which was shown by the facts that transgenic plants had distinct growth superiority and significantly higher survival rate than non-transformed ones under high salinity and high osmosis stresses, and that relative electronic conductivity of in vitro leaves treated with low and high temoeratures, dehvdration and high salinity stresses was 25-30% lower in transgenic plants than in control plants.In addition,it was observed that growth of transgenic plants was inhibited due to constitutive overexpression of CBF1 gene under normal environmental conditions.
文摘Glycinebetaine(GB),an osmotic substance,could improve some stress tolerance in plants.CodA gene,originating from bacteria,could translate choline oxidase which stimulates the synthesis of GB in plants.To create lily lines resistant to heat,Belladonna lily and Yelloween lily had been transferred CodA gene through Agrobacterium tumefaciens.The bacteria harbored a binary vector carrying the hygromycin phosphotransferase,choline oxidase(CodA)and intron-containingβ-glucuronidase(Gus)genes were co-cultivated with lily bulb scales slides.The result showed that most the bulb scales had developed into bulblets in a regulator-free growth medium,while some expressed the hygromycin-resistance,heat tolerance and Gus gene expression.Among them,one line demonstrated primarily the transcription level expression through reverse transcription polymerase chain reaction(RT-PCR).Moreover,they were tested with the accumulation of GB which was evident that the transferred line had four times of GB volumes higher than that of wild type.The original evidence could open a right approach to enhance stress tolerance in lily plants.
文摘Genetic transformation is a useful technique to complement conventional breeding in crop improvement. Although carrot has been a model organism for in vitro embryogenesis study, genetic transformation of carrot is still lengthy and labor intensive. An efficient transformation and detection system is desirable. Direct infection of Agrobacterium to carrot calli has provided an easy way for carrot genetic transformation. To improve the efficiency of antibiotic selection in this method, we report the combined use of an improved green-fluorescent protein, referred to as smGFP, to establish a versatile selection method for carrot callus transformation system. By combining antibiotic selection with the bright fluorescence observed in the callus tissue, we were able to easily identify stable transformants in early stage of the transformation process. In addition to the GFP expression of the callus cells, the transgenic nature of callus cells was confirmed with Southern and Western analysis. We found we can link the simplicity of carrot-callus-cell transformation, early detection of stable transformants with antibiotic selection, visualization of GFP fluorescence, and molecular analysis （Southern and Western） of callus tissue （non-photosynthetic tissue） to provide a more efficient way in identifying stable transformants at early stage of carrot transformation.
文摘In this study, CryⅠA(b) gene was successfully transferred into the biocontrol fungus Trichoderma har- zianum with an efficiency of 60—180 transformants per 106 spores by using Agrobacterium tumefaciens-mediated trans- formation. Putative transformants were analyzed to test the presence of CryⅠA(b) gene by Southern blot. Most trans- formants contained a single T-DNA copy. RT-PCR analysis showed that the CryⅠA(b) gene was transcribed. Antifungal activities and insecticidal activities of the transformants were examined. There was no obvious difference in antifungal activities between the transformants and their wild strains. The modified mortalities of the transformants T1 and T2 were 69.57% and 91.30%, respectively. The tranformation system mediated by A. tumefaciens proved to be a powerful tool for the filamentous fungi transformation and functional genomic study with its high transformation frequency, sim- plicity of T-DNA integration, and genetic stability of transformants.
文摘The flower’s meristematic characteristic gene AP1 was introduced into Chrysanthemum morifolium cv. ‘Yu Ren Mian’ mediated by Agrobacterium tumefaciens.The factors influencing genetic transformation protocol were studied.The results showed that the leaf explants precultured for 2～8 hours or not precultured were best for transformation by A. tumefaciens. The suitable concentration of bacterial and the time for infecting was OD_ 600 0.5 for 10 minutes. Leaves were cocultivated with bacterial at 23～25 ℃ for 2 days,then delayed selection for 3 days. Kan^r plant were selected by increased selective press from 5 mg·L ~ -1 G418 to 7.5 mg5L~ -1 G418 followed by 10 mg5L~ -1 G418. The integration of AP1 gene into C. morifolium ‘Yu Ren Mian’ was confirmed by PCR and Southern blotting.Two of transgenic plants bloomed 15 days earlier than untransformed plants.
