Since maize is one of the most important cereal crops in the world,establishment of an efficient genetic transformation system is critical for its improvement.In the current study,several elite corn lines were tested ...Since maize is one of the most important cereal crops in the world,establishment of an efficient genetic transformation system is critical for its improvement.In the current study,several elite corn lines were tested for suitability of Agrobacterium tumefaciens-mediated transformation by using immature embryos as explants.Infection ability and efficiency of transformation of A.tumefaciens sp.strains EHA105 and LBA4404,different heat treatment times of immature embryos before infection,influence of L-cysteine addition in co-cultivation medium after transformation,and how different ways of selection and cultivation influence the efficiency of transformation were compared.Glyphosate-resistant gene 2mG2-EPSPS was transformed into several typical maize genotypes including 78599,Zong 31 and BA,under the optimum conditions.Results showed that the hypervirulent Agrobacterium tumefaciens sp.strain EHA105 was more infectious than LBA4404.Inclusion of L-cysteine（100 mg L-1） in co-cultivation medium,and heating of the immature embryos for 3 min prior to infection led to a significant increase in the transformation efficiency.Growth in resting medium for 4-10 d and delaying selection was beneficial to the survival of resistant calli.During induction of germination,adding a high concentration of 6-BA（5 mg L-1） and a low concentration of 2,4-D（0.2 mg L-1） to regeneration medium significantly enhanced germination percentage.Using the optimized transformation procedure,more than 800 transgenic plants were obtained from 78599,Zong 31 and BA.By spraying herbicide glyphosate on leaves of transgenic lines,we identified 66 primary glyphosate-resistant plants.The transformation efficiency was 8.2%.PCR and Southern-blot analyses confirmed the integration of the transgenes in the maize genome.展开更多
To construct the T-DNA insertional mutagenesis transformation system for rice sheath blight pathogen Rhizoctonia solani AG-1 IA,the virulent isolate GD118 of this pathogen was selected as an initial isolate for transf...To construct the T-DNA insertional mutagenesis transformation system for rice sheath blight pathogen Rhizoctonia solani AG-1 IA,the virulent isolate GD118 of this pathogen was selected as an initial isolate for transformation.The conditions for transformation of isolate GD118 were optimized in five aspects,i.e.pre-induction time,co-culture time,acetosyringone(AS) concentration at the co-culture phase,co-culture temperature and pH value of induction solid medium(ISM) at the co-culture phase.Finally,a system of Agrobacterium tumefaciens-mediated transformation(ATMT) for R.solani AG-1 IA was established successfully.The optimal conditions for this ATMT system were as follows:the concentration of hygromycin B at 30 μg/mL for transformant screening,8 h of pre-induction,20 h of co-culture,200 μmol/L of AS in ISM,co-culture at 25 ℃ and pH 5.6 to 5.8 of ISM at the co-culture phase.The transformants still displayed high resistance to hygromycin B after subculture for five generations.A total of 10 randomly selected transformants were used for PCR verification using the specific primers designed for the hph gene,and the results revealed that an expected band of 500 bp was amplified from all of the 10 transformants.Moreover,PCR amplification for these 10 transformants was carried out using specific primers designed for the Vir gene of A.tumefaciens,with four strains of A.tumefaciens as positive controls for eliminating the false-positive caused by the contamination of A.tumefaciens.An expected band of 730 bp was amplified from the four strains of A.tumefaciens,whereas no corresponding DNA band could be amplified from the 10 transformants.The results of the two PCR amplifications clearly showed that T-DNA was indeed inserted into the genome of target isolate GD118.展开更多
Insect pest and weeds are two major problems for forage and turf grasses. In this study, scarab larvae- and herbicide-resistant transgenic perennial ryegrass （Lolium perenne L.） was obtained by transforming it with ...Insect pest and weeds are two major problems for forage and turf grasses. In this study, scarab larvae- and herbicide-resistant transgenic perennial ryegrass （Lolium perenne L.） was obtained by transforming it with cry and bar genes simultaneously via the Agrobacterium-mediated method. To optimize the callus induction and plant regeneration conditions, various concentrations of 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine were assayed. The transformation efficiencies of different Agrobacterium suspension media, used during Agrobacterium-mediated transformation, were compared. Then, plasmids of pCAMBIA3301 containing cry gene （cry8Ca2 or cry8Ga） and bar gene, driven by ubiquitin promoter, were transformed into perennial ryegrass. The transformants were generated and confirmed by both Southern hybridization analysis and Western hybridization analysis. Further, the resistance of transgenic perennial ryegrass plants to scarab larvae and herbicide were analyzed. After 30 d of co-cultivation with scarab larvae, the damage to the root system of transgenic plants was less than that of non-transgenic control plants. Additionally, the leaves of transgenic plants were resistant to Basta, while leaves of the wild plants wilted after Basta spraying. These results show that cry gene and bar gene were successfully transferred into perennial ryegrass by the Agrobactgerium-mediated method, and convey resistance to scarab larvae and herbicide in transgenic perennial ryegrass plants.展开更多
[ Objective ] This study aimed to establish Agrobacterium tumefaciens-mediated genetic transformation system for Aspergillus awamori and investigate the feasibility of expressing heterologous proteins in A. awamori. [...[ Objective ] This study aimed to establish Agrobacterium tumefaciens-mediated genetic transformation system for Aspergillus awamori and investigate the feasibility of expressing heterologous proteins in A. awamori. [ Method] Appropriate A. awamori host strains were determined according to the secretory protein profile. Selectable marker was selected for genetic transformation by drug sensitivity analysis. The established A. awamori genetic transformation system was used for transformation and expression analysis of Rhizomucor miehei lipase （RML）. The feasibility of using A. awamori to express heterologous proteins was investigated by identification of transformants and property analysis. [ Result~ Based on the analysis of secretory protein profile, A. awamori strains CBS115.52 and CICC2257 were determined as the host strains for heterologous protein expression ; drug sensitivity analysis shows that hygromycin B resistance gene （ HygBr ） is an effective ge- netic seleetable marker; by using Agrobacterium tumefaciens-mediatcd transformation （ATMT） method, the plasmid pHGW-amdS containing HygBr was successfully transformed into A. awamori strain CBS115.52 to establish the genetic transformation system ofA. awamorl with HygBr as selectable marker. RML was transformed into A. awamori and its expression was validated by substrate hydrolysis test, SDS-PAGE and Western blot. [ Conclusion] This study demonstrates that the genetic transformation system of A. awamori mediated by Agrobacterium tumefaciens has potential feasibility for expression of heterologous proteins.展开更多
The regeneration ability of four alfalfa （Medicago sativa L.） cultivars, Xinjiang Daye, Longdong, Gannong 1 and Gannong 3, was studied, and the effects of various cultivars, explant sources and medium recipes on reg...The regeneration ability of four alfalfa （Medicago sativa L.） cultivars, Xinjiang Daye, Longdong, Gannong 1 and Gannong 3, was studied, and the effects of various cultivars, explant sources and medium recipes on regeneration were compared. The better callus forming frequency obtained from hypocotyls of Xinjiang Daye is 88.5% and regeneration frequency is 9.8% in our initial experiments. To further optimize regeneration system for genetic transformation, we therefore changed concentrations of plant growth regulators and supplemented with glutamine into callus-induction and shoot-regeneration media. Callus forming frequency and shoot differentiation frequency were increased to 100%. The time taken to generate transgenic plants （16 weeks） was shorter than that for previouse procedure （25 weeks） and regeneration frequency was promoted to 15.1%. The results show that addition of glutamine is particularly important for shortening period of regeneration and promoting regeneration frequency. For study of genetic transformation of alfalfa, Agrobacterium tumefaciens-mediated transformation of Xinjiang Daye was developed based on this optimized regeneration system. The plant expression vector carrying two glutamine synthetases （GS 1 and GS2） and △1-pyrroline-5-carboxylate synthetase （P5CS） gene was used for alfalfa in vitro transformation. Six transgenic alfalfa plantlets with resistance to PPT were obtained. The introduction of foreign genes into plants was assessed in the transformants by PCR analysis and Southern hybridizations.展开更多
The objective of this study was to increase the resistance of rape using the method of transformation. The gene hrf2 derived from Xathomonas oryzae pv. oryzicola encoding harpinxooc protein was constructed into transg...The objective of this study was to increase the resistance of rape using the method of transformation. The gene hrf2 derived from Xathomonas oryzae pv. oryzicola encoding harpinxooc protein was constructed into transgenic vector pCAMBIA1301. The cotyledonal petiole segments from rapeseed variety Yangyou 4 were infected by Agrobacterium tumefaciens strain LBA4404/pCAMBIA1301-hrf2. Hygromycin-resistant green shoots were obtained. Successful integration of the foreign gene into the genome of the rapeseed variety Yangyou 4 was confirmed by PCR, RT-PCR, and β-glucuronidase analyses. Disease bioassays of transgenic plants revealed an improved resistance of transgenic plants to Rape sclerotiniose. In brief, the hrf2 gene can be transferred into rape using the method of Agrobacterium-mediated transformation, which increased the resistance to Sclerotinia sclerotinorium in the transgenic plant.展开更多
Transfer DNA （T-DNA） of Agrobacterium tumefaciens integration in the plant genome may lead to rearrangements of host plant chromosomal fragments, including inversions. However, there is very little information conce...Transfer DNA （T-DNA） of Agrobacterium tumefaciens integration in the plant genome may lead to rearrangements of host plant chromosomal fragments, including inversions. However, there is very little information concerning the inversion. The present study re- ports a transgenic rice line selected from a T-DNA tagged population, which displays a semi-dwarf phenotype. Molecular analysis of this mutant indicated an insertion of two tandem copies of T-DNA into a locus on the rice genome in a head to tail mode. This insertion of T-DNA resulted in the inversion of a 4.9 Mb chromosomal segment. Results of sequence analysis suggest that the chromosomal inversion resulted from the insertion of T-DNA with the help of sequence microhomology between insertion region of T-DNA and target sequence of the host plant.展开更多
基金supported by the National Key Project of transgenic varieties breeding(2009ZX08003-003B)the Light of West Talent Training Project of China(2010-2011)the Project of Sichuan Province Finance Genetic Engineering,China(2011JYGC01-002)
文摘Since maize is one of the most important cereal crops in the world,establishment of an efficient genetic transformation system is critical for its improvement.In the current study,several elite corn lines were tested for suitability of Agrobacterium tumefaciens-mediated transformation by using immature embryos as explants.Infection ability and efficiency of transformation of A.tumefaciens sp.strains EHA105 and LBA4404,different heat treatment times of immature embryos before infection,influence of L-cysteine addition in co-cultivation medium after transformation,and how different ways of selection and cultivation influence the efficiency of transformation were compared.Glyphosate-resistant gene 2mG2-EPSPS was transformed into several typical maize genotypes including 78599,Zong 31 and BA,under the optimum conditions.Results showed that the hypervirulent Agrobacterium tumefaciens sp.strain EHA105 was more infectious than LBA4404.Inclusion of L-cysteine（100 mg L-1） in co-cultivation medium,and heating of the immature embryos for 3 min prior to infection led to a significant increase in the transformation efficiency.Growth in resting medium for 4-10 d and delaying selection was beneficial to the survival of resistant calli.During induction of germination,adding a high concentration of 6-BA（5 mg L-1） and a low concentration of 2,4-D（0.2 mg L-1） to regeneration medium significantly enhanced germination percentage.Using the optimized transformation procedure,more than 800 transgenic plants were obtained from 78599,Zong 31 and BA.By spraying herbicide glyphosate on leaves of transgenic lines,we identified 66 primary glyphosate-resistant plants.The transformation efficiency was 8.2%.PCR and Southern-blot analyses confirmed the integration of the transgenes in the maize genome.
基金supported by a ‘Special Fund for Agro-scientific Research in the Public Interest’ from the Ministry of Agriculture of China(Grant No.nyhyzx3-16)
文摘To construct the T-DNA insertional mutagenesis transformation system for rice sheath blight pathogen Rhizoctonia solani AG-1 IA,the virulent isolate GD118 of this pathogen was selected as an initial isolate for transformation.The conditions for transformation of isolate GD118 were optimized in five aspects,i.e.pre-induction time,co-culture time,acetosyringone(AS) concentration at the co-culture phase,co-culture temperature and pH value of induction solid medium(ISM) at the co-culture phase.Finally,a system of Agrobacterium tumefaciens-mediated transformation(ATMT) for R.solani AG-1 IA was established successfully.The optimal conditions for this ATMT system were as follows:the concentration of hygromycin B at 30 μg/mL for transformant screening,8 h of pre-induction,20 h of co-culture,200 μmol/L of AS in ISM,co-culture at 25 ℃ and pH 5.6 to 5.8 of ISM at the co-culture phase.The transformants still displayed high resistance to hygromycin B after subculture for five generations.A total of 10 randomly selected transformants were used for PCR verification using the specific primers designed for the hph gene,and the results revealed that an expected band of 500 bp was amplified from all of the 10 transformants.Moreover,PCR amplification for these 10 transformants was carried out using specific primers designed for the Vir gene of A.tumefaciens,with four strains of A.tumefaciens as positive controls for eliminating the false-positive caused by the contamination of A.tumefaciens.An expected band of 730 bp was amplified from the four strains of A.tumefaciens,whereas no corresponding DNA band could be amplified from the 10 transformants.The results of the two PCR amplifications clearly showed that T-DNA was indeed inserted into the genome of target isolate GD118.
基金supported by the National Basic Research Program of China (973 Program,2007CB1089).
文摘Insect pest and weeds are two major problems for forage and turf grasses. In this study, scarab larvae- and herbicide-resistant transgenic perennial ryegrass （Lolium perenne L.） was obtained by transforming it with cry and bar genes simultaneously via the Agrobacterium-mediated method. To optimize the callus induction and plant regeneration conditions, various concentrations of 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine were assayed. The transformation efficiencies of different Agrobacterium suspension media, used during Agrobacterium-mediated transformation, were compared. Then, plasmids of pCAMBIA3301 containing cry gene （cry8Ca2 or cry8Ga） and bar gene, driven by ubiquitin promoter, were transformed into perennial ryegrass. The transformants were generated and confirmed by both Southern hybridization analysis and Western hybridization analysis. Further, the resistance of transgenic perennial ryegrass plants to scarab larvae and herbicide were analyzed. After 30 d of co-cultivation with scarab larvae, the damage to the root system of transgenic plants was less than that of non-transgenic control plants. Additionally, the leaves of transgenic plants were resistant to Basta, while leaves of the wild plants wilted after Basta spraying. These results show that cry gene and bar gene were successfully transferred into perennial ryegrass by the Agrobactgerium-mediated method, and convey resistance to scarab larvae and herbicide in transgenic perennial ryegrass plants.
文摘[ Objective ] This study aimed to establish Agrobacterium tumefaciens-mediated genetic transformation system for Aspergillus awamori and investigate the feasibility of expressing heterologous proteins in A. awamori. [ Method] Appropriate A. awamori host strains were determined according to the secretory protein profile. Selectable marker was selected for genetic transformation by drug sensitivity analysis. The established A. awamori genetic transformation system was used for transformation and expression analysis of Rhizomucor miehei lipase （RML）. The feasibility of using A. awamori to express heterologous proteins was investigated by identification of transformants and property analysis. [ Result~ Based on the analysis of secretory protein profile, A. awamori strains CBS115.52 and CICC2257 were determined as the host strains for heterologous protein expression ; drug sensitivity analysis shows that hygromycin B resistance gene （ HygBr ） is an effective ge- netic seleetable marker; by using Agrobacterium tumefaciens-mediatcd transformation （ATMT） method, the plasmid pHGW-amdS containing HygBr was successfully transformed into A. awamori strain CBS115.52 to establish the genetic transformation system ofA. awamorl with HygBr as selectable marker. RML was transformed into A. awamori and its expression was validated by substrate hydrolysis test, SDS-PAGE and Western blot. [ Conclusion] This study demonstrates that the genetic transformation system of A. awamori mediated by Agrobacterium tumefaciens has potential feasibility for expression of heterologous proteins.
基金supported by the National Special Program for Research and Industrialization of Transgenic Plants,China(J2002-B-008)
文摘The regeneration ability of four alfalfa （Medicago sativa L.） cultivars, Xinjiang Daye, Longdong, Gannong 1 and Gannong 3, was studied, and the effects of various cultivars, explant sources and medium recipes on regeneration were compared. The better callus forming frequency obtained from hypocotyls of Xinjiang Daye is 88.5% and regeneration frequency is 9.8% in our initial experiments. To further optimize regeneration system for genetic transformation, we therefore changed concentrations of plant growth regulators and supplemented with glutamine into callus-induction and shoot-regeneration media. Callus forming frequency and shoot differentiation frequency were increased to 100%. The time taken to generate transgenic plants （16 weeks） was shorter than that for previouse procedure （25 weeks） and regeneration frequency was promoted to 15.1%. The results show that addition of glutamine is particularly important for shortening period of regeneration and promoting regeneration frequency. For study of genetic transformation of alfalfa, Agrobacterium tumefaciens-mediated transformation of Xinjiang Daye was developed based on this optimized regeneration system. The plant expression vector carrying two glutamine synthetases （GS 1 and GS2） and △1-pyrroline-5-carboxylate synthetase （P5CS） gene was used for alfalfa in vitro transformation. Six transgenic alfalfa plantlets with resistance to PPT were obtained. The introduction of foreign genes into plants was assessed in the transformants by PCR analysis and Southern hybridizations.
文摘The objective of this study was to increase the resistance of rape using the method of transformation. The gene hrf2 derived from Xathomonas oryzae pv. oryzicola encoding harpinxooc protein was constructed into transgenic vector pCAMBIA1301. The cotyledonal petiole segments from rapeseed variety Yangyou 4 were infected by Agrobacterium tumefaciens strain LBA4404/pCAMBIA1301-hrf2. Hygromycin-resistant green shoots were obtained. Successful integration of the foreign gene into the genome of the rapeseed variety Yangyou 4 was confirmed by PCR, RT-PCR, and β-glucuronidase analyses. Disease bioassays of transgenic plants revealed an improved resistance of transgenic plants to Rape sclerotiniose. In brief, the hrf2 gene can be transferred into rape using the method of Agrobacterium-mediated transformation, which increased the resistance to Sclerotinia sclerotinorium in the transgenic plant.
基金supported by the National High Technology Development Program of China (No.2008AA10Z104)China Postdoctoral Science Foundation (No.20060600519)
文摘Transfer DNA （T-DNA） of Agrobacterium tumefaciens integration in the plant genome may lead to rearrangements of host plant chromosomal fragments, including inversions. However, there is very little information concerning the inversion. The present study re- ports a transgenic rice line selected from a T-DNA tagged population, which displays a semi-dwarf phenotype. Molecular analysis of this mutant indicated an insertion of two tandem copies of T-DNA into a locus on the rice genome in a head to tail mode. This insertion of T-DNA resulted in the inversion of a 4.9 Mb chromosomal segment. Results of sequence analysis suggest that the chromosomal inversion resulted from the insertion of T-DNA with the help of sequence microhomology between insertion region of T-DNA and target sequence of the host plant.
