Dissociation (Ds) transposon is one of thetransposable elements in corn. The trans-posons can be transferred into other plantswhere the transposons were not found. Oncethe transposon was inserted into target gene ofth...Dissociation (Ds) transposon is one of thetransposable elements in corn. The trans-posons can be transferred into other plantswhere the transposons were not found. Oncethe transposon was inserted into target gene ofthese plants, it could be used as a marker todistinguish and isolate the gene. The object ofthis study is to transfer Ds transposon to riceby Agrobacterium -mediated transformation.The calli of immature embryos, mature展开更多
Genetic transformation of rice(Oryza sativa L.) by introducing beneficial traits is now a central research instrument in plant physiology and a practical tool for plant improvement. Many approaches are verified for st...Genetic transformation of rice(Oryza sativa L.) by introducing beneficial traits is now a central research instrument in plant physiology and a practical tool for plant improvement. Many approaches are verified for stable introduction of foreign genes into the plant genome. The review examined the different constraints that limit the success of rice genetic transformation via Agrobacterium-mediated approach and suggested possible solutions. Explant identification, gene transfer technique and construct to tailor the integration, transgene expression without collateral to genetic damage and transformant selection are among the technical challenges affecting the rice transformation. Despite the contests, Agrobacteriummediated transformation system has been a better option for producing transgenic rice varieties because of its exact T-DNA processing and simple integration of low copy-number transgene. This information is necessary for improving the transformation system for recalcitrant rice varieties.展开更多
CrylAb gene was transformed into four rice varieties, Zhejing 22, Zhejing 27, Jiahua 1 and Xiushui 63 mediated by Agrobacterium-mixture co-transformation. Rice genotype had an important effect on callus induction and ...CrylAb gene was transformed into four rice varieties, Zhejing 22, Zhejing 27, Jiahua 1 and Xiushui 63 mediated by Agrobacterium-mixture co-transformation. Rice genotype had an important effect on callus induction and transformation efficiency. Different mixtures of Agrobacterium strains （EHA105 and EHA101） contained Hpt and CrylAb genes resulted in different frequencies of resistant calli. There was no correlation between the frequency of transformants with the ratio of the Agrobacterium strain mixture contained Hpt and CrylAb genes. A total of 509 transgenic plants were obtained from the four rice varieties, and 272 T2 progenies were analyzed for CrylAb and Hpt genes. PCR analysis revealed that 412 regenerated plants were Hpt positive （80.94%）, 62 plants were also CrylAb co-transformants （15.05% in total frequency）, and 42 plants among the 272 T2 progenies were CrylAb positive but Hpt negative. This suggests that marker-free transgenic plants could be produced by co-transformation mediated by mixed Agrobacterium strains with the selectable marker gene and target gene Southern blot analysis of five independent marker-free T2 transgenic lines co-transformed from Zhejing 22 showed that CrylAb gene had been inserted into rice genome with a single copy. The transgenic plants showed significantly stronger resistance to lepidopteron than the non-transgenic plants under no application of insecticides against lepidopteron.展开更多
Abstract: The homodimeric hemoglobin gene (VHb), the trans-zeatin synthetase gene (tzs), the modified 5-enolpyruvylshikimate-3-phosphate synthase gene (EPSPS), a selectable marker gene (hpt), and a reporter gene (gus)...Abstract: The homodimeric hemoglobin gene (VHb), the trans-zeatin synthetase gene (tzs), the modified 5-enolpyruvylshikimate-3-phosphate synthase gene (EPSPS), a selectable marker gene (hpt), and a reporter gene (gus), as linked expression cassettes, were stacked into the T-DNA region of a binary vector and introduced simultaneously into immature embryos of the rice (Oryza sativa L.) varieties Xiushui-11, Qiufeng, Youfeng, and Hanfeng by Agrobacterium tumefaciens. A total of 1 153 transgenic lines was obtained through selection for hygromycin B resistance. Approximately 90.2% of the transgenic lines harbored all the transgenes. Integration of multiple transgenes occurred at one to three genetic loci. Expression analysis revealed that the transgenes were coexpressed and inherited in a simple Mendelian fashion in transgenic plants and the frequency of coexpression was approximately 85%. On the basis of the cointegration and coexpression of the transgenes, most transgenic families were considered to be useful in a breeding program.展开更多
Either bacterial attachment or cellulose fibrillar elaboration was hardly observedduring the cocultivation of the cultured suspension cells of Oryza sativa Indica with thestrain C58C1 Rif^r of Agrobacterium tumefacien...Either bacterial attachment or cellulose fibrillar elaboration was hardly observedduring the cocultivation of the cultured suspension cells of Oryza sativa Indica with thestrain C58C1 Rif^r of Agrobacterium tumefaciens that was not specially pretreated. Onthe other hand, quite a lot of Agrobacterium cells were found to adhere to the surface ofcultured rice cells and a number of cellulose fibrils were produced around the specifiedbacteria when phenolics-pretreated bacteria were cocultivated with rice suspension cellsin common culture media, especially in complex culture solutions. The complex culturesolution was the bacterium-free filtrate of hormone-containing MS medium which hadbeen utilized to incubate carrot cells and the newly wounded hypocotyl segments fromtomato and Agrobacterium cells. Detecting experiments demonstrated that both NPT Ⅱ andNOS genes, located on the T-DNA segment of chimaeric plasmid pGV3850 :: 1103neo, weretransferred and expressed in the cultured cells of O. sativa Indica in展开更多
Aurones belong to a small class of flavonoids that provide yellow color in some floricultural plants including snapdragon. To explore novel flower coloration, two full-length cDNAs encoding chalcone 4'-O-glucosylt...Aurones belong to a small class of flavonoids that provide yellow color in some floricultural plants including snapdragon. To explore novel flower coloration, two full-length cDNAs encoding chalcone 4'-O-glucosyltransferase (designated as SRY4'CGT) and aureusidin synthase (designated as SRYAS1) in the aurone biosynthetic pathway were cloned from yellow flowers of snapdragon (Antirrhinum majus cv. Ribbon Yellow). Binary vectors were constructed and transformed separately into Petunia hybrida harboring blue flowers. Only a few flowers in 4 out of 9 transgenic SRY4'CGT plants showed variegated blue-white sectors;as time passed, amounts of variegated flowers and proportion of white sectors in the background blue color of the new-born flowers gradually increased, until finally, the petal color was completely white in all late-born flowers. In contrast, a few flowers in 3 out of 13 transgenic SRYAS1 plants showed variegated blue-white sectors;but, the amounts of variegated flowers did not increase over the whole flowering stage, and no complete white flowers were observed. RNA samples isolated from blue and white sectors of T1 transgenic SRY4'CGT plants were analyzed by reverse transcription-PCR, transgenic SRY4'CGT transcripts were detected in both sectors;however, transcripts of an upstream gene, chalcone synthase (CHS), were abundantly detected in the blue sectors but largely reduced in the white sectors, suggesting that the expression of CHS gene was suppressed in white sectors of transgenic plants. Furthermore, HPLC coupled with mass spectrometry demonstrated cyandin, malvidin and their derivatives were absent in white sectors, causing the white phenotype. Our findings may be attractive to molecular breeders.展开更多
文摘Dissociation (Ds) transposon is one of thetransposable elements in corn. The trans-posons can be transferred into other plantswhere the transposons were not found. Oncethe transposon was inserted into target gene ofthese plants, it could be used as a marker todistinguish and isolate the gene. The object ofthis study is to transfer Ds transposon to riceby Agrobacterium -mediated transformation.The calli of immature embryos, mature
文摘Genetic transformation of rice(Oryza sativa L.) by introducing beneficial traits is now a central research instrument in plant physiology and a practical tool for plant improvement. Many approaches are verified for stable introduction of foreign genes into the plant genome. The review examined the different constraints that limit the success of rice genetic transformation via Agrobacterium-mediated approach and suggested possible solutions. Explant identification, gene transfer technique and construct to tailor the integration, transgene expression without collateral to genetic damage and transformant selection are among the technical challenges affecting the rice transformation. Despite the contests, Agrobacteriummediated transformation system has been a better option for producing transgenic rice varieties because of its exact T-DNA processing and simple integration of low copy-number transgene. This information is necessary for improving the transformation system for recalcitrant rice varieties.
基金supported by the Zhejiang Provincial Natural Science Foundation of China (Grant No.Z305650 and No.Y3080361)the Science and Technology Department of Zhejiang Province,China (Grant No.2004C12020)+1 种基金the National Key Technology Research & Development Program,China (Grant No.2006BAD01A01-5 and No.2008ZX08001-001)the 151 Foundation for the Talents of Zhejiang Province,China
文摘CrylAb gene was transformed into four rice varieties, Zhejing 22, Zhejing 27, Jiahua 1 and Xiushui 63 mediated by Agrobacterium-mixture co-transformation. Rice genotype had an important effect on callus induction and transformation efficiency. Different mixtures of Agrobacterium strains （EHA105 and EHA101） contained Hpt and CrylAb genes resulted in different frequencies of resistant calli. There was no correlation between the frequency of transformants with the ratio of the Agrobacterium strain mixture contained Hpt and CrylAb genes. A total of 509 transgenic plants were obtained from the four rice varieties, and 272 T2 progenies were analyzed for CrylAb and Hpt genes. PCR analysis revealed that 412 regenerated plants were Hpt positive （80.94%）, 62 plants were also CrylAb co-transformants （15.05% in total frequency）, and 42 plants among the 272 T2 progenies were CrylAb positive but Hpt negative. This suggests that marker-free transgenic plants could be produced by co-transformation mediated by mixed Agrobacterium strains with the selectable marker gene and target gene Southern blot analysis of five independent marker-free T2 transgenic lines co-transformed from Zhejing 22 showed that CrylAb gene had been inserted into rice genome with a single copy. The transgenic plants showed significantly stronger resistance to lepidopteron than the non-transgenic plants under no application of insecticides against lepidopteron.
文摘Abstract: The homodimeric hemoglobin gene (VHb), the trans-zeatin synthetase gene (tzs), the modified 5-enolpyruvylshikimate-3-phosphate synthase gene (EPSPS), a selectable marker gene (hpt), and a reporter gene (gus), as linked expression cassettes, were stacked into the T-DNA region of a binary vector and introduced simultaneously into immature embryos of the rice (Oryza sativa L.) varieties Xiushui-11, Qiufeng, Youfeng, and Hanfeng by Agrobacterium tumefaciens. A total of 1 153 transgenic lines was obtained through selection for hygromycin B resistance. Approximately 90.2% of the transgenic lines harbored all the transgenes. Integration of multiple transgenes occurred at one to three genetic loci. Expression analysis revealed that the transgenes were coexpressed and inherited in a simple Mendelian fashion in transgenic plants and the frequency of coexpression was approximately 85%. On the basis of the cointegration and coexpression of the transgenes, most transgenic families were considered to be useful in a breeding program.
文摘Either bacterial attachment or cellulose fibrillar elaboration was hardly observedduring the cocultivation of the cultured suspension cells of Oryza sativa Indica with thestrain C58C1 Rif^r of Agrobacterium tumefaciens that was not specially pretreated. Onthe other hand, quite a lot of Agrobacterium cells were found to adhere to the surface ofcultured rice cells and a number of cellulose fibrils were produced around the specifiedbacteria when phenolics-pretreated bacteria were cocultivated with rice suspension cellsin common culture media, especially in complex culture solutions. The complex culturesolution was the bacterium-free filtrate of hormone-containing MS medium which hadbeen utilized to incubate carrot cells and the newly wounded hypocotyl segments fromtomato and Agrobacterium cells. Detecting experiments demonstrated that both NPT Ⅱ andNOS genes, located on the T-DNA segment of chimaeric plasmid pGV3850 :: 1103neo, weretransferred and expressed in the cultured cells of O. sativa Indica in
文摘Aurones belong to a small class of flavonoids that provide yellow color in some floricultural plants including snapdragon. To explore novel flower coloration, two full-length cDNAs encoding chalcone 4'-O-glucosyltransferase (designated as SRY4'CGT) and aureusidin synthase (designated as SRYAS1) in the aurone biosynthetic pathway were cloned from yellow flowers of snapdragon (Antirrhinum majus cv. Ribbon Yellow). Binary vectors were constructed and transformed separately into Petunia hybrida harboring blue flowers. Only a few flowers in 4 out of 9 transgenic SRY4'CGT plants showed variegated blue-white sectors;as time passed, amounts of variegated flowers and proportion of white sectors in the background blue color of the new-born flowers gradually increased, until finally, the petal color was completely white in all late-born flowers. In contrast, a few flowers in 3 out of 13 transgenic SRYAS1 plants showed variegated blue-white sectors;but, the amounts of variegated flowers did not increase over the whole flowering stage, and no complete white flowers were observed. RNA samples isolated from blue and white sectors of T1 transgenic SRY4'CGT plants were analyzed by reverse transcription-PCR, transgenic SRY4'CGT transcripts were detected in both sectors;however, transcripts of an upstream gene, chalcone synthase (CHS), were abundantly detected in the blue sectors but largely reduced in the white sectors, suggesting that the expression of CHS gene was suppressed in white sectors of transgenic plants. Furthermore, HPLC coupled with mass spectrometry demonstrated cyandin, malvidin and their derivatives were absent in white sectors, causing the white phenotype. Our findings may be attractive to molecular breeders.
