In order to promote the research of transgenic insect-resistant maize,the target gene were transferred into maize material Hi-Ⅱ by Agrobacterium-mediated genetic transformation of maize embryos,and maize plants with ...In order to promote the research of transgenic insect-resistant maize,the target gene were transferred into maize material Hi-Ⅱ by Agrobacterium-mediated genetic transformation of maize embryos,and maize plants with CryNGc insect-resistant genes were cultured by explant infection,co-culture and differentiation screening to study the genetic expression and resistance of exogenous genes in the offspring.The results showed that the infection effect was the best when the size of young maize embryo was 1.2-1.8 mm.Ten positive transformed plants with CryNGc insect-resistant genes were successfully obtained,and the transformation efficiency was 1.428‰.展开更多
By using the method of pollen tube pathway, the synthesized GFM CryIA gene and modified CpTI gene were transfered into the elite cotton( Gossypium hirsutun L. ) varieties(lines). Through the field and lab identificati...By using the method of pollen tube pathway, the synthesized GFM CryIA gene and modified CpTI gene were transfered into the elite cotton( Gossypium hirsutun L. ) varieties(lines). Through the field and lab identifications, the insect-resistant transgenic plants were obtained. PCR analysis indicated that both the synthesized GFM CryIA gene and modified CpTI gene presented positive reaction. In R1 the boliworm resistance of each transformant was different, and the insect-resistance of R3 of ZGK9708 was stable.展开更多
There are currently three kinds of transgenic Bt insect-resistant cotton germplasm lines, Shanxi 94-24, Zhongxin 94 and R19, in China. They showed high resistance to the neonate larvae of bollworm (Helicoverpa armiger...There are currently three kinds of transgenic Bt insect-resistant cotton germplasm lines, Shanxi 94-24, Zhongxin 94 and R19, in China. They showed high resistance to the neonate larvae of bollworm (Helicoverpa armigera). Transgenic Bt insect-resistant cotton varieties or hybrids have been bred using the three kinds of germplasm lines as parents. Our researches reveal that there exist different expressions in resistant level at different developmental stages in the three categories of germplasm lines. When neonate larvae are fed with leaves of cotton plant at the seeding stage with less than 10 leaves on the main stem, the mortality of the neonate larvae is 100%, but the resistance level will decline at later season. When Bt gene has been transferred to the cotton genome, it can be steadily transferred to the progeny, the level of resistance to bollworm keeps fundamentally uniform. Such insects as tobacco budworm (Heliothis virencens) in laboratory directive selection are very apt to produce resistance展开更多
Genetic and expressional stability of Bt toxin gene is crucial for the breeding of insect-resistant transgenic cotton varieties and their commercialization. Genomic Southern blot analysis of R3, R4 and R5 generations ...Genetic and expressional stability of Bt toxin gene is crucial for the breeding of insect-resistant transgenic cotton varieties and their commercialization. Genomic Southern blot analysis of R3, R4 and R5 generations of bivalent transgenic insect-resistant cotton plants was done in order to determine the integration, the copy number and the inheritance stability of Bt toxin gene in the transgenic cotton plants. The results indicated that there was a 4.7 kb positive band in the Southern blot when the genomic DNA of the bivalent transgenic insect-resistant cotton plants and the positive control (the plasmid) were digested with HindⅢ respectively. This result proved that the Bt toxin gene had been integrated into the genome of the cotton in full length. There is only one XhoⅠ restriction site in the Bt toxin gene. Southern blot analysis indicated that many copies of Bt toxin gene had been integrated into the genome of the cotton when the genomic DNA of transgenic plants was digested with XhoⅠ. Among them, there were four copies (about 17.7, 8, 5.5 and 4.7 kb in size) existing in all the tested plants of R3, R4 and R5 generations. The preliminary conclusion was that there were more than four copies of Bt toxin gene integrated into the genome of the cotton, among them, more than one copy can express and inherit steadily. This result provides a scientific basis for the breeding of the bivalent insect-resis- tant transgenic cotton plants and its commercialization.展开更多
ITHACA, N.Y. -- Ray J. Wu, Cornell University professor of molecular biology and genetics, who was widely recog-nized as one of the fathers of genetic engineering and who developed and sought to feed the world with a ...ITHACA, N.Y. -- Ray J. Wu, Cornell University professor of molecular biology and genetics, who was widely recog-nized as one of the fathers of genetic engineering and who developed and sought to feed the world with a higher yield-ing rice that resists insects and drought, died of cardiac arrest in Ithaca, Feb. 10.展开更多
Transgene escape from genetically modified (GM) rice into weedy rice via gene flow may cause undesired environmental consequences. Estimating the field performance of crop-weed hybrids will facilitate our understand...Transgene escape from genetically modified (GM) rice into weedy rice via gene flow may cause undesired environmental consequences. Estimating the field performance of crop-weed hybrids will facilitate our understanding of potential introgression of crop genes (including transgenes) into weedy rice populations, allowing for effective biosafety assessment. Comparative studies of three weedy rice strains and their hybrids with two GM rice lines containing different insect- resistance transgenes (CpTI or Bt/CpTI) indicated an enhanced relative performance of the crop-weed hybrids, with taller plants, more tillers, panicles, and spikelets per plant, as well as higher 1000-seed weight, compared with the weedy rice parents, although the hybrids produced less filled seeds per plant than their weedy parents. Seeds from the F1 hybrids had higher germination rates and produced more seedlings than the weedy parents, which correlated positively with 1000-seed weight. The crop-weed hybrids demonstrated a generally enhanced relative performance than their weedy rice parents in our field experiments. These findings indicate that transgenes from GM rice can persist to and introgress into weedy rice populations through recurrent crop-to-weed gene flow with the aid of slightly increased relative fitness in F1 hybrids.展开更多
The synthesized Bacillus thuringiensis insecticidal protein gene crylA(b&c) and the synthesized gene GNA, (the mannose specific lectin from snowdrop ( Galanthus nivalis)), tumefaciens have been inserted into plant...The synthesized Bacillus thuringiensis insecticidal protein gene crylA(b&c) and the synthesized gene GNA, (the mannose specific lectin from snowdrop ( Galanthus nivalis)), tumefaciens have been inserted into plant expression vector pGW4BAI. Leave stripes of Nico-tiana tabacum var. K326 have been transformed with Agrobacterium tumefaciens strain LBA4404 harboring the plant expression vector. 28 kanamycin resistant tobacco plants展开更多
MicroRNAs(miRNAs)can participate in plant-insect interactions,which regulate plant defense networks.In this study,we analyzed the miRNA expression profiles of six rice varieties before and after brown planthopper(BPH)...MicroRNAs(miRNAs)can participate in plant-insect interactions,which regulate plant defense networks.In this study,we analyzed the miRNA expression profiles of six rice varieties before and after brown planthopper(BPH)-feeding.We identified 45 differentially expressed miRNAs between BPH-susceptible and BPH-resistant rice varieties and 144 miRNAs that responded to BPH-feeding.Thus,miRNAs may be involved in multiple pathways regulating rice defense response against BPH.In addition,we found that the genetic history of rice varieties determined the regulation mode of the miRNA and affected the amounts,types,changing trends and response periods of miRNAs in response to BPH-feeding.To conclude,we scanned seven potential cross-kingdom miRNAs,of which miR5795 may target the vitellogenin gene in BPH,causing a 16.07%reduction in BPH oviposition.The results provide new miRNA information of rice-BPH interactions and BPH-resistant rice variety breeding.展开更多
A cDNA library was constructed with 1.5×10~6 pfu from rice immature seeds,fromwhich a cDNA clone for rice thiol proteinase inhibitor,oryzacystatin(OC),was isolated byscreening with synthesized oligodeoxynucleotid...A cDNA library was constructed with 1.5×10~6 pfu from rice immature seeds,fromwhich a cDNA clone for rice thiol proteinase inhibitor,oryzacystatin(OC),was isolated byscreening with synthesized oligodeoxynucleotide probe,which contained a 309bp open read-ing frame,84bp 5′-end noncoding region and a poly(A)signal AATAAA at the 3′-end fol-lowed by 31Nt poly(A).Then the coding region of OC was amplified and inserted into thedownstream of λP_RP_L promoter for thermal-inducible expression in E.coli.Shifting the cul-ture temperature from 30℃ to 42℃ led to a high level expression of OC,which exhibited adistinct band of 12.0 kDa and accounted for at least 10% of the total soluble proteins fromSDS-PAGE.The papain-inhibitory activity of the expressed OC was further confirmed.展开更多
Extensive planting of Bacillus thuringiensis (Bt)-transgenic plants economically benefits society; how-ever, the potential risk they pose is receiving increasing attention. This study used enzyme-linked immunosorben...Extensive planting of Bacillus thuringiensis (Bt)-transgenic plants economically benefits society; how-ever, the potential risk they pose is receiving increasing attention. This study used enzyme-linked immunosorbent assay and fluorescence quantitative PCR (RT-PCR) to monitor the temporal and spatial dynamics of the expression of Bt toxic protein in a forest of 6- to 8-year-old trees of transgenic insect-resistant poplar 741 for three consec- utive years. The enrichment, distribution, and degradation of Bt toxic protein and the influence of transgenic poplars on the targeted insect population, Hyphantria cunea, were investigated. The content of CrylAc toxic protein dynamically changed in transgenic poplar. During the annual growth cycle, the content initially increased, then decreased in the long and the short branches of the crown and in the root system, peaking in August. During the study, the protein did not accumulate overtime. The mRNA transcription of gene CrylAc was almost consistent with the level of the protein, but transcription peaked in July. In the transgenic and control forestland, microscale levels of the CrylAc toxic protein were detected from the soil, but increased accumulation was not observed with the planting year of transgenic poplar. Meanwhile, Bt was isolated and detected molecularly from the soil in the experimental forestland. A systematic investigation of the density of H. cunea in the experimental transgenic poplar forest indi- cated that transgenic Pb29 poplar could resist insects to a certain degree. At peak occurrence of the targeted insects, the density of H. cunea in the experimental forest was significantly lower than in the nontransgenic poplar forest.展开更多
Insecticidal protein gene CryIA(c)from Bacillus thuringiensis HD-1(B.t.toxin gene)with 5’-end modified and 3’-end deleted to 4 different lengths were inserted downstream of 35S promoterwith double enhancer and"...Insecticidal protein gene CryIA(c)from Bacillus thuringiensis HD-1(B.t.toxin gene)with 5’-end modified and 3’-end deleted to 4 different lengths were inserted downstream of 35S promoterwith double enhancer and"Ω’"fragment of TMV-RNA cDNA in the binary vector pBin438 to constructthe chimeric expression vector of B.t.toxin gene.Leave stripes of tobacco plant var.NC89 widelygrown in China were transformed with A.tumefaciens LBA4404 harbouring the above expression vectorsrespectively,and kanamycin resistant tobacco plants were regenerated.Insect test with tobacco budwormH.assulta showed that insect-resistant transform.ants could be obtained from the regenerated plantstransformed with B.t.genes of different lengths though highest percentage(~50%)of plants with ahigh morality(90%-100%)to the testing insects is among those transformed with 1.8-kb toxin gene.Genetic,molecular and biological analyses of T1 and T2 progenies of plants with high efficient insect re-sistance showed that B.t.toxin gene and the character of insect resistance have been inherited in the pro-genies.Insect-resistant homozygotes D8-14 and D19-8 have been selected for small-scale field tests.展开更多
In the development, of transgenic Bt + CpTI cotton cultivars, one male and female sterile mutant has been found in a homozygous T4 strain in our laboratory. The mutant plant, as well as its leaves, buds and flowers, i...In the development, of transgenic Bt + CpTI cotton cultivars, one male and female sterile mutant has been found in a homozygous T4 strain in our laboratory. The mutant plant, as well as its leaves, buds and flowers, is only 1/2-1/3 as large as that of the wild transgenic Bt + CpTI bivalant cotton plants. Cytological observation found that the chromosome number of the mutant is 2n=52; however, there are 4-8 univalents observed in meiosis I of pollen mother cells. Laboratory bioassay indicated that the mutant was highly resistant to bollworm as the wild plants. PCRamplification revealed that Bt and CpTl genes in the mutant were still intactly inserted. However, small deletion of flanked area had been observed in the mutant by Southern blotting analysis. So it is proposed that the mutant pheno-type might result from either the DNA deletion or T-DNA transferring in plant genome. No such report has been presented that the rearrangement of chromosome structure in a homozygous transgenic line occurred.展开更多
Total RNA was extracted from rice immature seeds harvested 2 weeks after flowering; then mRNA was purified. cDNA with NotI and SaiI cohesive ends was synthesized and inserted into λgt22A. After packaged in vitno, the...Total RNA was extracted from rice immature seeds harvested 2 weeks after flowering; then mRNA was purified. cDNA with NotI and SaiI cohesive ends was synthesized and inserted into λgt22A. After packaged in vitno, the cDNA library was constructed with 1.5×106pfu. A 21-mer oligodeoxynucleotide was synthesized according to the 5’-end conserved coding sequence of oryzacystatin (a thiol proteinase inhibitor) and labeled as a probe. From 2.1 × 104 pfu, 9 positive dones have been isolated, 8 of which contain the entire coding region of oryzacystatin. λOC1 has the longest cDNA insert, which contains an open reading frame of 309 bp coding sequence, 84 bp 5’-end non-coding region and a poly(A) signal AATAAA at the 3’-end followed by 31 Nt of poly(A). The coding sequence is the same compared with oryzacystatin genomic DNA sequence, while there are some obvious differences such as insertion and variation in the non-coding region, especially lots of nonsucoessive insertion in the 3’ region after poly(A) signal.展开更多
There are 3 kinds of transgenic Bt strains, Shanxi 94-24, Zhongxin 94, and R19, in upland cotton in China. Their transgenic Bt insect-resistance cultivars or hybrids have been developed and grown by farmers. Genetic s...There are 3 kinds of transgenic Bt strains, Shanxi 94-24, Zhongxin 94, and R19, in upland cotton in China. Their transgenic Bt insect-resistance cultivars or hybrids have been developed and grown by farmers. Genetic studies indicate that the resistance of the 3 transgenic Bt cotton strains to Helicoverpa armigera is controlled by one pair of non-allelic dominant genes. Linkage relationship between the resistant genes of R19 and Shanxi 94-24 transgenic Bt strains shows that they may be inserted in the same chromosome. FT hybrids crossed among the 3 strains show that high levels of protection from feeding damage are the same as that of their parents. Therefore, there is no co-suppression phenomenon in many transgenic plants. The results presented here afford a fundamental reliance in developing transgenic Bt insect-resistant cultivars and exploiting the heterosis of hybrids in upland cotton.展开更多
基金Supported by Strategic Leading Science and Technology Project of Chinese Academy of Sciences(XDA28130504)Special Project of Agricultural Science and Technology Innovation Leaping Project of Heilongjiang Academy of Agricultural Sciences(HNK2019CX14)Scientific Research Fund Project of Heilongjiang Provincial Scientific Research Institutes(CZKYF2021C008)。
文摘In order to promote the research of transgenic insect-resistant maize,the target gene were transferred into maize material Hi-Ⅱ by Agrobacterium-mediated genetic transformation of maize embryos,and maize plants with CryNGc insect-resistant genes were cultured by explant infection,co-culture and differentiation screening to study the genetic expression and resistance of exogenous genes in the offspring.The results showed that the infection effect was the best when the size of young maize embryo was 1.2-1.8 mm.Ten positive transformed plants with CryNGc insect-resistant genes were successfully obtained,and the transformation efficiency was 1.428‰.
文摘By using the method of pollen tube pathway, the synthesized GFM CryIA gene and modified CpTI gene were transfered into the elite cotton( Gossypium hirsutun L. ) varieties(lines). Through the field and lab identifications, the insect-resistant transgenic plants were obtained. PCR analysis indicated that both the synthesized GFM CryIA gene and modified CpTI gene presented positive reaction. In R1 the boliworm resistance of each transformant was different, and the insect-resistance of R3 of ZGK9708 was stable.
文摘There are currently three kinds of transgenic Bt insect-resistant cotton germplasm lines, Shanxi 94-24, Zhongxin 94 and R19, in China. They showed high resistance to the neonate larvae of bollworm (Helicoverpa armigera). Transgenic Bt insect-resistant cotton varieties or hybrids have been bred using the three kinds of germplasm lines as parents. Our researches reveal that there exist different expressions in resistant level at different developmental stages in the three categories of germplasm lines. When neonate larvae are fed with leaves of cotton plant at the seeding stage with less than 10 leaves on the main stem, the mortality of the neonate larvae is 100%, but the resistance level will decline at later season. When Bt gene has been transferred to the cotton genome, it can be steadily transferred to the progeny, the level of resistance to bollworm keeps fundamentally uniform. Such insects as tobacco budworm (Heliothis virencens) in laboratory directive selection are very apt to produce resistance
基金supported by the National"863"High-Tech Program,the Special Foundation of the Ministry of Agriculture for"Developing Cotton Production"and the Chinese Foundation for Agriculture Science and Education.
文摘Genetic and expressional stability of Bt toxin gene is crucial for the breeding of insect-resistant transgenic cotton varieties and their commercialization. Genomic Southern blot analysis of R3, R4 and R5 generations of bivalent transgenic insect-resistant cotton plants was done in order to determine the integration, the copy number and the inheritance stability of Bt toxin gene in the transgenic cotton plants. The results indicated that there was a 4.7 kb positive band in the Southern blot when the genomic DNA of the bivalent transgenic insect-resistant cotton plants and the positive control (the plasmid) were digested with HindⅢ respectively. This result proved that the Bt toxin gene had been integrated into the genome of the cotton in full length. There is only one XhoⅠ restriction site in the Bt toxin gene. Southern blot analysis indicated that many copies of Bt toxin gene had been integrated into the genome of the cotton when the genomic DNA of transgenic plants was digested with XhoⅠ. Among them, there were four copies (about 17.7, 8, 5.5 and 4.7 kb in size) existing in all the tested plants of R3, R4 and R5 generations. The preliminary conclusion was that there were more than four copies of Bt toxin gene integrated into the genome of the cotton, among them, more than one copy can express and inherit steadily. This result provides a scientific basis for the breeding of the bivalent insect-resis- tant transgenic cotton plants and its commercialization.
文摘ITHACA, N.Y. -- Ray J. Wu, Cornell University professor of molecular biology and genetics, who was widely recog-nized as one of the fathers of genetic engineering and who developed and sought to feed the world with a higher yield-ing rice that resists insects and drought, died of cardiac arrest in Ithaca, Feb. 10.
基金Supported by the Ministry of Science and Technology (2007CB10920206)the National Natural Science Foundation of China (30730066 and30871503)
文摘Transgene escape from genetically modified (GM) rice into weedy rice via gene flow may cause undesired environmental consequences. Estimating the field performance of crop-weed hybrids will facilitate our understanding of potential introgression of crop genes (including transgenes) into weedy rice populations, allowing for effective biosafety assessment. Comparative studies of three weedy rice strains and their hybrids with two GM rice lines containing different insect- resistance transgenes (CpTI or Bt/CpTI) indicated an enhanced relative performance of the crop-weed hybrids, with taller plants, more tillers, panicles, and spikelets per plant, as well as higher 1000-seed weight, compared with the weedy rice parents, although the hybrids produced less filled seeds per plant than their weedy parents. Seeds from the F1 hybrids had higher germination rates and produced more seedlings than the weedy parents, which correlated positively with 1000-seed weight. The crop-weed hybrids demonstrated a generally enhanced relative performance than their weedy rice parents in our field experiments. These findings indicate that transgenes from GM rice can persist to and introgress into weedy rice populations through recurrent crop-to-weed gene flow with the aid of slightly increased relative fitness in F1 hybrids.
文摘The synthesized Bacillus thuringiensis insecticidal protein gene crylA(b&c) and the synthesized gene GNA, (the mannose specific lectin from snowdrop ( Galanthus nivalis)), tumefaciens have been inserted into plant expression vector pGW4BAI. Leave stripes of Nico-tiana tabacum var. K326 have been transformed with Agrobacterium tumefaciens strain LBA4404 harboring the plant expression vector. 28 kanamycin resistant tobacco plants
基金supported by the Key Realm Research and Development Program of Guangdong Province,China (Grant No. 2020B0202090001)the Foundation of Guangzhou Science and Technology Key Project,China (Grant No. 201904020041)
文摘MicroRNAs(miRNAs)can participate in plant-insect interactions,which regulate plant defense networks.In this study,we analyzed the miRNA expression profiles of six rice varieties before and after brown planthopper(BPH)-feeding.We identified 45 differentially expressed miRNAs between BPH-susceptible and BPH-resistant rice varieties and 144 miRNAs that responded to BPH-feeding.Thus,miRNAs may be involved in multiple pathways regulating rice defense response against BPH.In addition,we found that the genetic history of rice varieties determined the regulation mode of the miRNA and affected the amounts,types,changing trends and response periods of miRNAs in response to BPH-feeding.To conclude,we scanned seven potential cross-kingdom miRNAs,of which miR5795 may target the vitellogenin gene in BPH,causing a 16.07%reduction in BPH oviposition.The results provide new miRNA information of rice-BPH interactions and BPH-resistant rice variety breeding.
基金Supported by Prime Minister FouNdationthe High Techriology Research and Development Programme of ChinaRockefeller Foun-dation.
文摘A cDNA library was constructed with 1.5×10~6 pfu from rice immature seeds,fromwhich a cDNA clone for rice thiol proteinase inhibitor,oryzacystatin(OC),was isolated byscreening with synthesized oligodeoxynucleotide probe,which contained a 309bp open read-ing frame,84bp 5′-end noncoding region and a poly(A)signal AATAAA at the 3′-end fol-lowed by 31Nt poly(A).Then the coding region of OC was amplified and inserted into thedownstream of λP_RP_L promoter for thermal-inducible expression in E.coli.Shifting the cul-ture temperature from 30℃ to 42℃ led to a high level expression of OC,which exhibited adistinct band of 12.0 kDa and accounted for at least 10% of the total soluble proteins fromSDS-PAGE.The papain-inhibitory activity of the expressed OC was further confirmed.
基金supported by the National High Technology Research and Development Program of China(863 Program)(Grant No.2013AA102703)
文摘Extensive planting of Bacillus thuringiensis (Bt)-transgenic plants economically benefits society; how-ever, the potential risk they pose is receiving increasing attention. This study used enzyme-linked immunosorbent assay and fluorescence quantitative PCR (RT-PCR) to monitor the temporal and spatial dynamics of the expression of Bt toxic protein in a forest of 6- to 8-year-old trees of transgenic insect-resistant poplar 741 for three consec- utive years. The enrichment, distribution, and degradation of Bt toxic protein and the influence of transgenic poplars on the targeted insect population, Hyphantria cunea, were investigated. The content of CrylAc toxic protein dynamically changed in transgenic poplar. During the annual growth cycle, the content initially increased, then decreased in the long and the short branches of the crown and in the root system, peaking in August. During the study, the protein did not accumulate overtime. The mRNA transcription of gene CrylAc was almost consistent with the level of the protein, but transcription peaked in July. In the transgenic and control forestland, microscale levels of the CrylAc toxic protein were detected from the soil, but increased accumulation was not observed with the planting year of transgenic poplar. Meanwhile, Bt was isolated and detected molecularly from the soil in the experimental forestland. A systematic investigation of the density of H. cunea in the experimental transgenic poplar forest indi- cated that transgenic Pb29 poplar could resist insects to a certain degree. At peak occurrence of the targeted insects, the density of H. cunea in the experimental forest was significantly lower than in the nontransgenic poplar forest.
基金the Key Programme of the 7th Five-Year Plan,State Planning Commission of ChinaInternational Centre of Science and Culture (ICSC),World Laboratory,Lausanne,Switzerland
文摘Insecticidal protein gene CryIA(c)from Bacillus thuringiensis HD-1(B.t.toxin gene)with 5’-end modified and 3’-end deleted to 4 different lengths were inserted downstream of 35S promoterwith double enhancer and"Ω’"fragment of TMV-RNA cDNA in the binary vector pBin438 to constructthe chimeric expression vector of B.t.toxin gene.Leave stripes of tobacco plant var.NC89 widelygrown in China were transformed with A.tumefaciens LBA4404 harbouring the above expression vectorsrespectively,and kanamycin resistant tobacco plants were regenerated.Insect test with tobacco budwormH.assulta showed that insect-resistant transform.ants could be obtained from the regenerated plantstransformed with B.t.genes of different lengths though highest percentage(~50%)of plants with ahigh morality(90%-100%)to the testing insects is among those transformed with 1.8-kb toxin gene.Genetic,molecular and biological analyses of T1 and T2 progenies of plants with high efficient insect re-sistance showed that B.t.toxin gene and the character of insect resistance have been inherited in the pro-genies.Insect-resistant homozygotes D8-14 and D19-8 have been selected for small-scale field tests.
基金theState "863" High-Tech Program and the Trans-century Training Program Foundation for the Talents by the State Education Commission to ZTZ.
文摘In the development, of transgenic Bt + CpTI cotton cultivars, one male and female sterile mutant has been found in a homozygous T4 strain in our laboratory. The mutant plant, as well as its leaves, buds and flowers, is only 1/2-1/3 as large as that of the wild transgenic Bt + CpTI bivalant cotton plants. Cytological observation found that the chromosome number of the mutant is 2n=52; however, there are 4-8 univalents observed in meiosis I of pollen mother cells. Laboratory bioassay indicated that the mutant was highly resistant to bollworm as the wild plants. PCRamplification revealed that Bt and CpTl genes in the mutant were still intactly inserted. However, small deletion of flanked area had been observed in the mutant by Southern blotting analysis. So it is proposed that the mutant pheno-type might result from either the DNA deletion or T-DNA transferring in plant genome. No such report has been presented that the rearrangement of chromosome structure in a homozygous transgenic line occurred.
基金Project supported by Prime Minister Foundation,863 Program Foundation and Rockefeller Foundation.
文摘Total RNA was extracted from rice immature seeds harvested 2 weeks after flowering; then mRNA was purified. cDNA with NotI and SaiI cohesive ends was synthesized and inserted into λgt22A. After packaged in vitno, the cDNA library was constructed with 1.5×106pfu. A 21-mer oligodeoxynucleotide was synthesized according to the 5’-end conserved coding sequence of oryzacystatin (a thiol proteinase inhibitor) and labeled as a probe. From 2.1 × 104 pfu, 9 positive dones have been isolated, 8 of which contain the entire coding region of oryzacystatin. λOC1 has the longest cDNA insert, which contains an open reading frame of 309 bp coding sequence, 84 bp 5’-end non-coding region and a poly(A) signal AATAAA at the 3’-end followed by 31 Nt of poly(A). The coding sequence is the same compared with oryzacystatin genomic DNA sequence, while there are some obvious differences such as insertion and variation in the non-coding region, especially lots of nonsucoessive insertion in the 3’ region after poly(A) signal.
文摘There are 3 kinds of transgenic Bt strains, Shanxi 94-24, Zhongxin 94, and R19, in upland cotton in China. Their transgenic Bt insect-resistance cultivars or hybrids have been developed and grown by farmers. Genetic studies indicate that the resistance of the 3 transgenic Bt cotton strains to Helicoverpa armigera is controlled by one pair of non-allelic dominant genes. Linkage relationship between the resistant genes of R19 and Shanxi 94-24 transgenic Bt strains shows that they may be inserted in the same chromosome. FT hybrids crossed among the 3 strains show that high levels of protection from feeding damage are the same as that of their parents. Therefore, there is no co-suppression phenomenon in many transgenic plants. The results presented here afford a fundamental reliance in developing transgenic Bt insect-resistant cultivars and exploiting the heterosis of hybrids in upland cotton.