Journal articles on the topic 'Transgenic tobacco'
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1
Kanthang, Supha, and Kanokporn Sompornpailin. "Increasing Plant Flavonoid Biomaterials in Response to UV-A Light." Advanced Materials Research 802 (September 2013): 74–78. http://dx.doi.org/10.4028/www.scientific.net/amr.802.74.
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Flavonoid biomaterials have a protecting function from various stresses. We examined the flavonoid biosynthesis in plant treated under visible light (VL) and additional UV-A light. The transgenic tobacco containing PRODUCTION OF ANTHOCYANIN PIGMENT 1 (PAP1) cDNA, involved in flavonoid biosynthesis from Arabidopsis thaliana, were used for studying the flavonoid biosynthesis under both light conditions comparing to non transgenic tobacco. The flavonoid biomaterials were extracted with acidic methanol and water solvent from treated plant leaves. The absorbance of each biomaterial in the extract was measured under specific wavelength using a spectrophotometer. Additional UV-A radiated to non transgenic and transgenic tobacco affect the increasing of p-coumaric acid, naringenin, apigenin and kaempherol biomaterials from themselves grown under VL (approximately 120-130%). However, PAP1 transgenic tobaccos under additional UV-A radiation enhance the accumulation of these biomaterials up to160-180% higher than non transgenic tobaccos grown under VL condition. Moreover, PAP1 transgenic tobacco radiated with UVA light also significantly increased pelargonidin biomaterial. PAP1 transgenic tobaccos had a similar phenotype with non transgenic tobaccos but the color of fully expanding flower was more pink intensity than non transgenic.
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Franco-Lara, Liliana F., Kara D. McGeachy, Uli Commandeur, Robert R. Martin, Mike A. Mayo, and Hugh Barker. "Transformation of tobacco and potato with cDNA encoding the full-length genome of Potato leafroll virus: evidence for a novel virus distribution and host effects on virus multiplication." Journal of General Virology 80, no. 11 (November 1, 1999): 2813–22. http://dx.doi.org/10.1099/0022-1317-80-11-2813.
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A full-length cDNA copy of the genome of Potato leafroll virus (PLRV) was introduced into the genome of tobacco and potato plants by Agrobacterium tumefaciens-mediated transformation. Transgenic lines were obtained in which the transgene was readily detected by PCR with DNA extracted from T1 tobacco seedlings and clonally multiplied potato plants. PLRV-specific genomic and sub- genomic RNAs, coat protein antigen and virus particles were detected in transgenic plants. Aphids fed on the transgenic tobacco plants readily transmitted PLRV to test plants. Infected transgenic tobacco plants, like non-transgenic (WT) PLRV-infected plants, displayed no symptoms of the infection but transgenic plants of potato were severely stunted. In parallel tests, the mean PLRV titres in WT tobacco plants and transgenic tobacco plants were 600 and 630 ng virus/g leaf, respectively, although differences in PLRV titres among transgenic plants were much greater than those among infected WT plants. In similar tests with potato, the mean PLRV titre of WT plants was 50 ng virus/g leaf whereas higher concentrations (up to 3400 ng virus/g leaf) accumulated in transgenic potato plants. In tissue prints of stems, PLRV was detected in similar proportions of phloem cells in transgenic and infected WT plants. In transgenic tobacco and potato plants, but not in infected WT plants, a few stem epidermal cells also contained virus. From tissue prints of transgenic tobacco leaves, it was estimated that about one in 40000 mesophyll cells contained virus, but in transgenic potato, a greater proportion of mesophyll cells was infected.
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Thủy, Lê Thị, Triệu Thị Hằng, Lâm Đại Nhân, and Lê Văn Sơn. "Assessment of the mannose inhibition on tobacco regeneration for establishment of a mannose selection system for transgenic plants." Vietnam Journal of Biotechnology 14, no. 1 (March 30, 2016): 131–38. http://dx.doi.org/10.15625/1811-4989/14/1/9303.
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Recently, the application of environmentally friendly methods in transgenic-plant selection has been exploited with an interest to contribute to the commercialization of transgenic products. In this study, mannose was chosen in selecting transgenic tobacco. The ability of mannose to inhibit tobacco regeneration was assessed through three stages: creating multi-shoot, elongating shoot, and rooting of tobacco cultivars K326 and C9-1. The results showed that mannose concentrations at 30 g/l and 20 g/l are suitable for creating multi-shoot of K326 and C9-1, respectively. In addition, mannose concentration at 30 g/l in combination with 7,5 g/l sucrose is fit for elongating shoot while its concentration at 30 g/l is appropriate for rooting transgenic tobacco in both K326 and C9-1 cultivars. The mannose selection of transgenic tobacco using gus gene showed that the transgenic effectiveness is ranging 16-17% of K326 and 9-11% of C9-1 cultivars. The successful establishment of mannose selection system in transgene tobacco contributes to generate bio-safety transgenic plants.
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Santoso, Tri Joko, Muhammad Herman, Sri H. Hidayat, Hajrial Aswidinnoor, and Sudarsono Sudarsono. "Molecular Analysis and Effectiveness Assay of AV1 Gene in Transgenic Tobacco for Resistance to Begomovirus." Jurnal AgroBiogen 8, no. 2 (August 15, 2016): 45. http://dx.doi.org/10.21082/jbio.v8n2.2012.p45-53.
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<p>Genetic transformation<br />of tobacco plant using AV1 gene was conducted at<br />the previously experiment and generated transgenic tobacco<br />plants positively carrying the selectable marker nptII gene.<br />The objectives of this experiment were to (1) analyze the<br />presence of Begomovirus AV1 gene in T0 generation putative<br />transgenic tobacco plants using PCR technique with specific<br />primers and its correlation with resistance phenotype, (2)<br />analyze the integration and copy number of the transgene in<br />T0 generation putative transgenic tobacco plants and its<br />correlation with resistance response, (3) screen the T0<br />generation putative transgenic tobacco plants with the target<br />virus infection and to detect the presence of the virus in the<br />transgenic plant tissue using universal primers. PCR<br />detection of AV1 gene in tobacco transgenic was conducted<br />by using specific primer for Begomovirus AV1 gene.<br />Meanwhile, Southern Blot analysis was conducted by using<br />the AV1 gene probe. The effectiveness of AV1 gene in<br />tobacco transgenic was tested by inoculation of target virus<br />using whiteflies vector. Result of the experiments showed<br />that there was a positive correlation between the presence<br />of the AV1 transgene in T0 generation putative transgenic<br />tobacco plants and the resistant phenotype. Transgenic<br />plants with a single copy integration of the transgene<br />exhibited more resistant than the multiple copy one. and<br />non transgenic plant. The resistance as a result of AV1 gene<br />expression was indicated with no symptom in T0 generation<br />transgenic tobacco plants and the accumulation of the virus<br />in the transgenic plants tissue. Northern and Western<br />hybridization analysis need to be perfomed for investigating<br />the presence of mRNA or protein accumulation so that the<br />resistance mechanism of the AV1 gene could be explained<br />more detail.</p>
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Duan, Yong-Ping, Charles A. Powell, Dan E. Purcifull, Peter Broglio, and Ernest Hiebert. "Phenotypic Variation in Transgenic Tobacco Expressing Mutated Geminivirus Movement/Pathogenicity (BC1) Proteins." Molecular Plant-Microbe Interactions® 10, no. 9 (December 1997): 1065–74. http://dx.doi.org/10.1094/mpmi.1997.10.9.1065.
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Tobacco plants were transformed with the movement protein (pathogenicity) gene (BC1) from tomato mottle gem-inivirus (TMoV), using Agrobacterium-mediated transformation. Different transgenic tobacco lines that expressed high levels of the BC1 protein had phenotypes ranging from plants with severe stunting and leaf mottling (resembling geminivirus symptoms) to plants with no visible symptoms. The sequence data for the BC1 transgene from the transgenic plants with the different phenotypes indicated an association of spontaneously mutated forms of the BC1 gene in the transformed tobacco with phenotype variations. One mutated transgene associated with an asymptomatic phenotype had a major deletion at the C terminus of 119 amino acid residues with a recombination resulting in the addition of 26 amino acid residues of unidentified origin. This asymptomatic, mutated BC1 attenuated the phenotypic expression of the symptomatic BC1 in a tobacco line containing both copies of the BC1 gene. Another mutated form of the BC1 gene amplified from an asymptomatic, multicopy transgenic tobacco plant did not induce symptoms when transiently expressed in tobacco via a virus vector. The symptom attenuation in the transgenic tobacco by the asymptomatic BC1 may involve trans-dominant negative interference.
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Pavlíková, D., T. Macek, M. Macková, M. Surá, J. Száková, and P. Tlustoš. "The evaluation of cadmium, zinc and nickel accumulation ability of transgenic tobacco bearing different transgenes." Plant, Soil and Environment 50, No. 12 (December 10, 2011): 513–17. http://dx.doi.org/10.17221/4067-pse.
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Tobacco, Nicotiana tabacum L., var. Wisconsin 38 as the control (WSC), and four genetically modified lines of the same variety, were tested for Cd, Zn and Ni accumulation. Genetically modified lines of the same variety, bearing the transgene CUP1 (gene coding a yeast metallothionein), GUS (reporter gene for ß-glucuronidase), HisCUP (CUP combined with a polyhistidine tail), and HisGUS (reporter gene for ß-glucuronidase, combined with a polyhistidine tail) under a constitutive promoter, enabling it to follow the heavy metal tolerance and uptake changes as a function of the transgene present. Control and transgenic lines were tested for accumulation of risk elements on sand nutrient medium with the addition of cadmium, zinc and nickel. The results showed high Cd accumulation ability of HisCUP line. The Cd content in aboveground biomass was increased by 90% compared to the non-transformed control and Cd content in roots was decreased by 49%. Determination of Zn content in aboveground biomass did not confirm higher uptake by transgenic plants significant for phytoremediation. The Ni content was significantly increased in aboveground biomass of HisGUS construct. GUS construct introduced the ability to accumulate all investigated metals; the others accumulated only one in extended amount.
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Jan, Fuh-Jyh, Carmen Fagoaga, Sheng-Zhi Pang, and Dennis Gonsalves. "A minimum length of N gene sequence in transgenic plants is required for RNA-mediated tospovirus resistance." Microbiology 81, no. 1 (January 1, 2000): 235–42. http://dx.doi.org/10.1099/0022-1317-81-1-235.
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We showed previously that transgenic plants with the green fluorescent protein (GFP) gene fused to segments of the nucleocapsid (N) gene of tomato spotted wilt virus (TSWV) displayed post-transcriptional gene silencing of the GFP and N gene segments and resistance to TSWV. These results suggested that a chimeric transgene composed of viral gene segments might confer multiple virus resistance in transgenic plants. To test this hypothesis and to determine the minimum length of the N gene that could trans-inactivate the challenging TSWV, transgenic plants were developed that contained GFP fused with N gene segments of 24–453 bp. Progeny from these plants were challenged with: (i) a chimeric tobacco mosaic virus containing the GFP gene, (ii) a chimeric tobacco mosaic virus with GFP plus the N gene of TSWV and (iii) TSWV. A number of transgenic plants expressing the transgene with GFP fused to N gene segments from 110 to 453 bp in size were resistant to these viruses. Resistant plants exhibited post-transcriptional gene silencing. In contrast, all transgenic lines with transgenes consisting of GFP fused to N gene segments of 24 or 59 bp were susceptible to TSWV, even though the transgene was post-transcriptionally silenced. Thus, virus resistance and post-transcriptional gene silencing were uncoupled when the N gene segment was 59 bp or less. These results provide evidence that multiple virus resistance is possible through the simple strategy of linking viral gene segments to a silencer DNA such as GFP.
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Cho, Eun Jin, Quynh Anh Nguyen, Yoon Gyo Lee, Younho Song, Bok Jae Park, and Hyeun-Jong Bae. "Enhanced Biomass Yield of and Saccharification in Transgenic Tobacco Over-Expressing β-Glucosidase." Biomolecules 10, no. 5 (May 23, 2020): 806. http://dx.doi.org/10.3390/biom10050806.
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Here, we report an increase in biomass yield and saccharification in transgenic tobacco plants (Nicotiana tabacum L.) overexpressing thermostable β-glucosidase from Thermotoga maritima, BglB, targeted to the chloroplasts and vacuoles. The transgenic tobacco plants showed phenotypic characteristics that were significantly different from those of the wild-type plants. The biomass yield and life cycle (from germination to flowering and harvest) of the transgenic tobacco plants overexpressing BglB were 52% higher and 36% shorter than those of the wild-type tobacco plants, respectively, indicating a change in the genome transcription levels in the transgenic tobacco plants. Saccharification in biomass samples from the transgenic tobacco plants was 92% higher than that in biomass samples from the wild-type tobacco plants. The transgenic tobacco plants required a total investment (US$/year) corresponding to 52.9% of that required for the wild-type tobacco plants, but the total biomass yield (kg/year) of the transgenic tobacco plants was 43% higher than that of the wild-type tobacco plants. This approach could be applied to other plants to increase biomass yields and overproduce β-glucosidase for lignocellulose conversion.
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Wang, B., H. Shen, X. Yang, T. Guo, B. Zhang, and W. Yan. "Effects of chitinase-transgenic (McChit1) tobacco on the rhizospheric microflora and enzyme activities of the purple soil ." Plant, Soil and Environment 59, No. 6 (May 22, 2013): 241–46. http://dx.doi.org/10.17221/704/2012-pse.
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In order to evaluate the bio-security of genetically modified (GM) plants in the purple soil, we carried out a pot experiment about rhizospheric microflora at different development stages of a chitinase-transgenic (McChit1) tobacco (T-Chit), a plasmid-transgenic tobacco (T-Vi), and a non-transgenic tobacco (Nt-X) that were grown in the same purple soil, and surveyed the growth of three tobaccos and the properties of soil (i.e. the dynamic changes of the cultivable rhizospheric bacteria and fungi, soil enzyme activity and pH). The results showed that, compared with Nt-X plant as a control, T-Chit and T-Vi at the stages of flowering and mature significantly decreased the number of cultivable rhizospheric bacteria, but at their stubble stage the bacteria number returned to the same levels. Moreover, there were no significant differences about the number of cultivable rhizospheric fungi and the ratio of fungi to bacteria (F/B) among three treatments. It was of interest that soil catalase activities of T-Chit and T-Vi were lower than that of Nt-X during the same period, and urease activities of T-Vi and T-Chit were also lower than that of Nt-X at the stages of budding and stubble. Protease activity and the biomass of tobacco, however, showed no significant difference. This indicated that 1-year-old transgenic tobacco plants (T-Vi and T-Chit) inhibited the catalase and urease activities of the purple soil. In conclusion, the results revealed that 1-year-old T-Chit and T-Vi plants were non-toxic to the colony-forming units of cultivable bacteria and fungi in the studied purple soil during tobacco growth.
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Qin, Li-Jun, Dan Zhao, Yi Zhang, and De-Gang Zhao. "Selectable marker-free co-expression of Nicotiana rustica CN and Nicotiana tabacum HAK1 genes improves resistance to tobacco mosaic virus in tobacco." Functional Plant Biology 42, no. 8 (2015): 802. http://dx.doi.org/10.1071/fp14356.
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The viral disease caused by tobacco mosaic virus (TMV) is the most prevalent viral disease in many tobacco production areas. A breeding strategy based on resistance genes is an effective method for improving TMV resistance in tobacco. Also, the physiological status of plants is also critical to disease resistance improvement. Potassium ion is one of the most abundant inorganic nutrients in plant cells, and mediates plant responses to abiotic and biotic stresses. Improving K+ content in soil by fertilising can enhance diseases resistance of crops. However, the K+ absorption in plants depends mostly on K+ transporters located in cytoplasmic membrane. Therefore, the encoding genes for K+ transporters are putative candidates to target for improving tobacco mosaic virus resistance. In this work, the synergistic effect of a N-like resistance gene CN and a tobacco putative potassium transporter gene HAK1 was studied. The results showed that TMV-resistance in CN-HAK1-containing tobaccos was significantly enhanced though a of strengthening leaf thickness and reduction in the size of necrotic spots compared with only CN-containing plants, indicating the improvement of potassium nutrition in plant cells could increase the tobacco resistance to TMV by reducing the spread of the virus. Quantitative real-time polymerase chain reaction (qRT–PCR) analysis for TMV-CP expression in the inoculated leaf of the transgenic and wild-type plants also supported the conclusion. Further, the results of defence-related determination including antioxidative enzymes (AOEs) activity, salicylic acid (SA) content and the expression of resistance-related genes demonstrated CN with HAK1 synergistically enhanced TMV-resistance in transgenic tobaccos. Additionally, the HAK1- overexpression significantly improved the photosynthesis and K+-enriching ability in trans-CN-HAK1 tobaccos, compared with other counterparts. Finally, this work provides a method for screening new varieties of marker-free and safe transgenic antiviral tobacco.
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Beachy, Roger N. "Coat–protein–mediated resistance to tobacco mosaic virus: discovery mechanisms and exploitation." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 354, no. 1383 (March 29, 1999): 659–64. http://dx.doi.org/10.1098/rstb.1999.0418.
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In 1986 we reported that transgenic plants which accumulate the coat protein of tobacco mosaic virus (TMV) are protected from infection by TMV, and by closely related tobamoviruses. The phenomenon is referred to as coat–protein–mediated resistance (CP–MR), and bears certain similarities to cross protection, a phenomenon described by plant pathologists early in this century. Our studies of CP–MR against TMV have demonstrated that transgenically expressed CP interferes with disassembly of TMV particles in the inoculated transgenic cell. However, there is little resistance to local, cell–to–cell spread of infection. CP–MR involves interaction between the transgenic CP and the CP of the challenge virus, and resistance to TMV is greater than to tobamoviruses that have CP genes more distantly related to the transgene. Using the known coordinates of the three–dimensional structure of TMV we developed mutant forms of CP that have stronger inter–subunit interactions, and confer increased levels of CP–MR compared with wild–type CP. Similarly, it is predicted that understanding the cellular and structural basis of CP–MR will lead to the development of variant CP transgenes that each can confer high levels of resistance against a range of tobamoviruses.
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Ma, Qing-Hu, Zhan-Bing Lin, and De-Zhi Fu. "Increased seed cytokinin levels in transgenic tobacco influence embryo and seedling development." Functional Plant Biology 29, no. 9 (2002): 1107. http://dx.doi.org/10.1071/pp01211.
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Seed-specific expression of a heterologous vicilin-isopentenyl transferase (ipt) gene has been determined in transgenic tobacco lines 7 and 16. Genetic analysis of self-fertilized progeny showed that a single copy of the vicilin-ipt gene had been integrated, and T2 progeny had become homozygous for the transgene. Stable inheritance of the vicilin-ipt gene in T3 progeny was verified by polymerase chain reaction analysis. Seed cytokinin levels were 2-3-fold higher than control levels. Cytological analyses revealed a significant increase in the number of plerome cell layers and enlargement of diameter in transgenic embryos compared with controls. Dry weight of mature seeds and subsequent seedling growth was increased significantly. This correlated with the level of vicilin-ipt overexpression and increased cytokinin levels in transgenic tobacco seeds. The results suggest a crucial role for cytokinins in regulation of tobacco embryo development.
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Canto, Tomas, and Peter Palukaitis. "Novel N Gene-Associated, Temperature-Independent Resistance to the Movement of Tobacco Mosaic Virus Vectors Neutralized by a Cucumber Mosaic Virus RNA1 Transgene." Journal of Virology 76, no. 24 (December 15, 2002): 12908–16. http://dx.doi.org/10.1128/jvi.76.24.12908-12916.2002.
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ABSTRACT The N gene conditions for resistance to Tobacco mosaic virus (TMV) but only below 28°C. However, a TMV-based vector expressing green fluorescent protein (TMV-GFP) showed only limited movement at 33°C in tobacco plants harboring the N gene and other genes cointrogressed from Nicotiana glutinosa. TMV-GFP moved efficiently in tobacco plants that either lacked these genes or that contained the N gene but were transgenic for RNA1 of Cucumber mosaic virus. These findings identified novel temperature-independent resistance to the movement of TMV-GFP which could be neutralized by a different viral transgene. Using the N gene and nahG gene-transgenic tobacco, we show that this novel resistance is manifested specifically by the N gene itself and operates via a pathway independent of salicylic acid.
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Sheng*, Jiping, Lin Shen, and Binggen Ru. "Effect of CdCl2 on the Growth and Antioxidases Activities in Transgenic Metallothionein and Wild Type Tobacco Leaves." HortScience 39, no. 4 (July 2004): 822A—822. http://dx.doi.org/10.21273/hortsci.39.4.822a.
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Metallothioneins (MTs) has selective capability to bind heavy metals such as Cd and Pb. Former study in our lab showed that MT gene from mouse was transferred into tobacco to absorb more heavy metals from soil. This study was conducted to plant transgenic tobacco and wild type tobacco on MS media with 20 μmol·L-1 CdCl2. Transgenic tobacco grew strong, whereas the growth of wild type tobacco was severely prohibited. At 21st day, an average single transgenic plant weight was 1.5 times higher than that of wild type, and its height was also 1.33 higher. The activities of antioxidases, such as POD, CAT, PPO in transgenic tobacco leaves showed significant lower than that of wild type, which was 32.3%, 43.3%, 187.5% lower respectively. The results indicated that the transgenic MT tobacco had higher Cd tolerance, and a promising future in the application of environmental cleaning.
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You-Ru, Wang, Cui Hong-Zhi, and Guo San-Dui. "Expression of modified VHb gene and fused insectidal gene in tobacco." Chinese Journal of Agricultural Biotechnology 5, no. 1 (April 2008): 27–31. http://dx.doi.org/10.1017/s1479236208002052.
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AbstractThe highly efficient plant binary expression vector pGBIF4ABCVHB was constructed using the artificially modified, synthesized VHb gene and fused insectidal gene (GFMcryIA and CPTI). Transgenic tobacco plants were obtained by Agrobacterium-mediated transformation. For 32 plants, the bivalent genes were inserted successfully into the tobacco genome and detected by polymerase chain reaction (PCR) amplification. Southern blot and Western blot analyses showed that VHb gene was expressed in the transgenic plants. Toxicity assay indicated that the fused insectidal gene expressed pesticidal toxin protein. The net weight of transgenic tobacco plants exceeded that of non-transgenic ones by 8%. Compared to non-transgenic tobacco plants, transgenic plants appeared to be high-yielding, insect-resistant varieties.
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Kanthang, Supha, and Kanokporn Sompornpailin. "Antioxidant Activity in the Petal Extract of PAP1 Transgenic Tobacco." Applied Mechanics and Materials 804 (October 2015): 195–98. http://dx.doi.org/10.4028/www.scientific.net/amm.804.195.
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Flavonoids are compounds which act as antioxidants in both plant and human. These substances are found in reproductive tissues. Tobaccos expressing ORF of PRODUCTION OF ANTHOCYANIN PIGMENT 1 (PAP1) involved in flavonoid biosynthesis were used for investigating the flavonoid profiles and antioxidant activity of petals and compared to wild type (WT) tobacco. Approximately two months, the tobacco grown in a culturing room had produced flowers for harvesting. The petal tissues were extracted with the solvent of acidic methanol and water. These extracts were measured the specific wavelength of flavonoid derivatives by using a spectrophotometer. The petal extract of H7 line showed the highest content of all detected flavonoid subgroups. However the petal extract of transgenic line H5 and H7 had significantly higher levels of anthocyanin (pelargonidin) than those of the other transgenic and WT tobaccos. An antioxidant activity of the petal extract was evaluated by 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•) assay. An effective concentration of the extract which scavenged DPPH radical by 50% (EC50) was presented. EC50 of the H5 and H7 transgenic extracts was approximately two folds less than that of WT extract Therefore anthocyanin may highly affect on antioxidant activities.
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Spencer, D., WG Rerie, PJ Randall, and TJV Higgins. "The Regulation of Pea Seed Storage Protein Genes by Sulfur Stress." Functional Plant Biology 17, no. 3 (1990): 355. http://dx.doi.org/10.1071/pp9900355.
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In this review the role of sulfur in regulating the expression of genes for pea seed storage proteins in both peas and transgenic tobacco is discussed. The levels of the sulfur-containing proteins, legumin and pea albumin 1 (PA1), are reduced in the seeds of peas grown under mild sulfur nutrient stress. In contrast, the levels of sulfur-poor proteins such as pea lectin and vicilin are either unaffected or increased slightly under the same conditions. The levels of all the proteins are a direct reflection of the levels of their respective mRNAs. The reduced levels of legumin and PA1 mRNAs under sulfur stress is known to be due largely to increased mRNA turnover rather than decreased transcription. The advent of gene transfer procedures for plants has allowed re-examination of the mechanism of regulation of mRNA stability under conditions of sulfur stress. A pea albumin 1 gene was engineered for leaf expression and transferred to tobacco and the transgenic plants were grown on normal and low levels of sulfur. Sulfur stress reduces total leaf protein in tobacco by about 20% and there are minor qualitative changes in the total protein profile. In contrast, PA1 levels are reduced by over 90% compared with the controls when the transgenic tobaccos are grown under sulfur stress. Thus, it is clear that sequences responsible for recognising the sulfur status have been included in the transgene. A number of gene constructs have been designed to test where the sulfur-responsive sequences are located in the PA1 gene and some of the preliminary findings are reported.
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Vernon, Daniel M., Mitchell C. Tarczynski, Richard G. Jensen, and Hans J. Bohnert. "Cyclitol production in transgenic tobacco." Plant Journal 4, no. 1 (July 1993): 199–205. http://dx.doi.org/10.1046/j.1365-313x.1993.04010199.x.
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Dieryck, Wilfrid, Josée Pagnier, Claude Poyart, Michael C. Marden, Véronique Gruber, Philippe Bournat, Sylvie Baudino, and Bertrand Mérot. "Human haemoglobin from transgenic tobacco." Nature 386, no. 6620 (March 1997): 29–30. http://dx.doi.org/10.1038/386029b0.
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Freitas-Astua, Juliana, Gustavo Astua-Monge, Jane Elisabeth Polston, and Ernest Hiebert. "A simple and reliable method for the screening of transgenic tobacco plants." Pesquisa Agropecuária Brasileira 38, no. 7 (July 2003): 893–96. http://dx.doi.org/10.1590/s0100-204x2003000700015.
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Even though much improvement has been made in plant transformation methods, the screening of transgenic plants is often a laborious work. Most approaches for detecting the transgene in transformed plants are still timeconsuming, and can be quite expensive. The objective of this study was to search for a simpler method to screen for transgenic plants. The infiltration of kanamycin (100 mg/mL) into tobacco leaves resulted in conspicuous chlorotic spots on the non-transgenic plant leaves, while no spots were seen on the leaves of transformed plants. This reaction occurred regardless of age of the tested plants, and the method has proven to be simple, fast, non-destructive, relatively cheap, and reliable. These results were comparable to those obtained by the polymerase chain reaction (PCR) amplification of the transgene using specific primers.
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Kai, Zhang, Niu Yan-Bing, and Zhou Xue-Ping. "Transgenic tobacco plants expressing dsRNA can prevent infection by Tobacco mosaic virus." Chinese Journal of Agricultural Biotechnology 2, no. 3 (December 2005): 201–5. http://dx.doi.org/10.1079/cjb200578.
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AbstractInverted repeats of the partial movement protein gene (ΔMP) of Tobacco mosaic virus (TMV) were introduced into the plant expression vector pBin438, and the recombinant plasmids were transformed into Agrobacterium tumefaciens EHA105 by a tri-parental mating method. Fifty transgenic plants of Nicotiana tabacum cv. Yunyan 87 were obtained after Agrobacterium-mediated transformation. PCR and Southern blot analyses showed that the target gene had integrated into the tobacco plant genome. When transgenic tobacco plants were challenged with TMV, symptoms expression and triple antibody sandwich enzyme-linked immunosorbent assay (TAS-ELISA) showed that transgenic plants had three kinds of phenotypes in response to the virus infection: immune (10%), resistant (4%) and susceptible (86%). Northern blot analysis showed that the levels of target mRNA accumulation varied among transgenic tobacco lines and a negative correlation between target mRNA accumulation and virus resistance was observed.
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Hezema, Yasmine S., Mukund R. Shukla, Alok Goel, Murali M. Ayyanath, Sherif M. Sherif, and Praveen K. Saxena. "Rootstocks Overexpressing StNPR1 and StDREB1 Improve Osmotic Stress Tolerance of Wild-Type Scion in Transgrafted Tobacco Plants." International Journal of Molecular Sciences 22, no. 16 (August 5, 2021): 8398. http://dx.doi.org/10.3390/ijms22168398.
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In grafted plants, the movement of long-distance signals from rootstocks can modulate the development and function of the scion. To understand the mechanisms by which tolerant rootstocks improve scion responses to osmotic stress (OS) conditions, mRNA transport of osmotic responsive genes (ORGs) was evaluated in a tomato/potato heterograft system. In this system, Solanum tuberosum was used as a rootstock and Solanum lycopersicum as a scion. We detected changes in the gene expression levels of 13 out of the 21 ORGs tested in the osmotically stressed plants; of these, only NPR1 transcripts were transported across the graft union under both normal and OS conditions. Importantly, OS increased the abundance of StNPR1 transcripts in the tomato scion. To examine mRNA mobility in transgrafted plants, StNPR1 and StDREB1 genes representing the mobile and non-mobile transcripts, respectively, were overexpressed in tobacco (Nicotiana tabacum). The evaluation of transgenic tobacco plants indicated that overexpression of these genes enhanced the growth and improved the physiological status of transgenic plants growing under OS conditions induced by NaCl, mannitol and polyethylene glycol (PEG). We also found that transgenic tobacco rootstocks increased the OS tolerance of the WT-scion. Indeed, WT scions on transgenic rootstocks had higher ORGs transcript levels than their counterparts on non-transgenic rootstocks. However, neither StNPR1 nor StDREB1 transcripts were transported from the transgenic rootstock to the wild-type (WT) tobacco scion, suggesting that other long-distance signals downstream these transgenes could have moved across the graft union leading to OS tolerance. Overall, our results signify the importance of StNPR1 and StDREB1 as two anticipated candidates for the development of stress-resilient crops through transgrafting technology.
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Sahoo, Dipak K., Sumita Raha, James T. Hall, and Indu B. Maiti. "Overexpression of the Synthetic Chimeric Native-T-phylloplanin-GFP Genes Optimized for Monocot and Dicot Plants Renders Enhanced Resistance to Blue Mold Disease in Tobacco (N. tabacumL.)." Scientific World Journal 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/601314.
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To enhance the natural plant resistance and to evaluate the antimicrobial properties of phylloplanin against blue mold, we have expressed a synthetic chimeric native-phylloplanin-GFP protein fusion in transgenicNicotiana tabacumcv. KY14, a cultivar that is highly susceptible to infection byPeronospora tabacina. The coding sequence of the tobacco phylloplanin gene along with its native signal peptide was fused with GFP at the carboxy terminus. The synthetic chimeric gene (native-phylloplanin-GFP) was placed between the modifiedMirabilis mosaic virusfull-length transcript promoter with duplicated enhancer domains and the terminator sequence from the rbcSE9 gene. The chimeric gene, expressed in transgenic tobacco, was stably inherited in successive plant generations as shown by molecular characterization, GFP quantification, and confocal fluorescent microscopy. Transgenic plants were morphologically similar to wild-type plants and showed no deleterious effects due to transgene expression. Blue mold-sensitivity assays of tobacco lines were performed by applyingP. tabacinasporangia to the upper leaf surface. Transgenic lines expressing the fused synthetic native-phyllopanin-GFP gene in the leaf apoplast showed resistance to infection. Our results demonstrate thatin vivoexpression of a synthetic fused native-phylloplanin-GFP gene in plants can potentially achieve natural protection against microbial plant pathogens, includingP. tabacinain tobacco.
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Ger, Mang-jye, Cheng-hsien Chen, Shaw-yhi Hwang, Hsiang-en Huang, Appa Rao Podile, Badri Venkata Dayakar, and Teng-yung Feng. "Constitutive Expression of hrap Gene in Transgenic Tobacco Plant Enhances Resistance Against Virulent Bacterial Pathogens by Induction of a Hypersensitive Response." Molecular Plant-Microbe Interactions® 15, no. 8 (August 2002): 764–73. http://dx.doi.org/10.1094/mpmi.2002.15.8.764.
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Hypersensitive response-assisting protein (HRAP) has been previously reported as an amphipathic plant protein isolated from sweet pepper that intensifies the harpinPss-mediated hypersensitive response (HR). The hrap gene has no appreciable similarity to any other known sequences, and its activity can be rapidly induced by incompatible pathogen infection. To assess the function of the hrap gene in plant disease resistance, the CaMV 35S promoter was used to express sweet pepper hrap in transgenic tobacco. Compared with wild-type tobacco, transgenic tobacco plants exhibit more sensitivity to harpinPss and show resistance to virulent pathogens (Pseudomonas syringae pv. tabaci and Erwinia carotovora subsp. carotovora). This disease resistance of transgenic tobacco does not originate from a constitutive HR, because endogenous level of salicylic acid and hsr203J mRNA showed similarities in transgenic and wild-type tobacco under noninfected conditions. However, following a virulent pathogen infection in hrap transgenic tobacco, hsr203J was rapidly induced and a micro-HR necrosis was visualized by trypan blue staining in the infiltration area. Consequently, we suggest that the disease resistance of transgenic plants may result from the induction of a HR by a virulent pathogen infection.
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Liu, Yun-Jun, Yuan Yuan, Jun Zheng, Ya-Zhong Tao, Zhi-Gang Dong, Jian-Hua Wang, and Guo-Ying Wang. "Signal Peptide of Potato PinII Enhances the Expression of Cry1Ac in Transgenic Tobacco." Acta Biochimica et Biophysica Sinica 36, no. 8 (August 1, 2004): 553–58. http://dx.doi.org/10.1093/abbs/36.8.553.
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Abstract The modified Cry1Ac was expressed in transgenic tobacco plants. To allow secretion of the Cry1Ac protein into the intercellular space, the signal peptide sequence of potato proteinase inhibitor II (pinII) was N-terminally fused to the Cry1Ac encoding region. Expression of Cry1Ac in transgenic tobacco plants was assayed with ELISA. The results showed that pinII signal peptide sequence enhanced the expression of Cry1Ac protein and led to the secretion of the Cry1Ac protein in transgenic tobacco plants. GFP gene was also fused to the signal peptide sequence and transformed to tobacco. The results of fluorescent detection showed that GFP had localized in the apoplast of transgenic plants.
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Xiuyun Zhao, Jianhong Yao,, Huaxiong Qi, Bingliang Wan, Fei Chen, Xiaofen Sun, Shanqian Yu, and Kexuan Tang. "Transgenic tobacco expressing an Arisaema heterophyllum agglutinin gene displays enhanced resistance to aphids." Canadian Journal of Plant Science 84, no. 3 (July 1, 2004): 785–90. http://dx.doi.org/10.4141/p03-036.
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Tobacco leaf discs were transformed with a plasmid, pBIAHA, containing the selectable marker neomycin phosphotransferase gene (nptII) and an Arisaema heterophyllum agglutinin gene (aha) via Agrobacterium tumefaciens-mediated transformation. Thirty-two independent transgenic tobacco plants were regenerated. PCR and Southern blot analyses confirmed that multiple copies of the aha gene had integrated into the plant genome. Northern blot analysis revealed that the aha gene was expressed at various levels in the transgenic plants. Insect bioassay test showed that transgenic plants expressing multiple copies of the aha gene reduced the rate of population increase of the peach potato aphid (Myzus persicae Sulzer). This is the first report that transgenic tobacco plants expressing the aha gene display enhanced resistance to aphids. Key words: Insect bioassay, Arisaema heterophyllum agglutinin, transformation, transgenic tobacco, peach potato aphid (Myzus persicae Sulzer)
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Han, Deguo, Haibin Ding, Lijing Chai, Wei Liu, Zhaoyuan Zhang, Yanjie Hou, and Guohui Yang. "Isolation and characterization of MbWRKY1, a WRKY transcription factor gene from Malus baccata (L.) Borkh involved in drought tolerance." Canadian Journal of Plant Science 98, no. 5 (October 1, 2018): 1023–34. http://dx.doi.org/10.1139/cjps-2017-0355.
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WRKY transcription factors are involved in stress responses in plants; however, their roles in abiotic stresses are still not well known in Malus plants. In the present study, a WRKY gene was isolated from Malus baccata (L.) Borkh and designated as MbWRKY1. Subcellular localization revealed that MbWRKY1 was localized in the nucleus. The expression levels of MbWRKY1 were up-regulated by dehydration, salinity, and ABA treatments in M. baccata seedlings. When MbWRKY1 was introduced into tobacco, it improved drought stress tolerance in transgenic plants. Under the drought treatment, transgenic plants had higher contents of chlorophyll, proline, relative water, AsA, and GSH than wild-type (WT) plants. Compared with WT plants, the overexpression of MbWRKY1 in transgenic tobacco also led to decreased levels of H2O2, MDA, and elecrolyte leakage when dealing with drought stress. There were increased activities of POD, CAT, SOD, and APX in transgenic tobaccos, especially when dealing with drought treatment. Moreover, the MbWRKY1 transgenic plants enhanced the expressions of oxidative stress response (NtPOD, NtCAT, NtSOD, and NtAPX) and stress-related genes (NtP5CS and NtLEA5) when dealing with drought stress. These results suggest that the MbWRKY1 gene plays a positive regulatory role in drought stress response.
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Phan, Loc Tuong, Ho Huu Nguyen, and Thanh Thi Nguyen. "PRELIMINARILY CHLOROPLAST TRANSFORMATION OF TOBACCO VARIETY V2 BY BOMBARDMENT." Science and Technology Development Journal 14, no. 1 (March 30, 2011): 35–46. http://dx.doi.org/10.32508/stdj.v14i1.1882.
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V2 is a high yield, large tobacco variety which is cultivated in many material areas of Vietnam. For successful chloroplast transformation, an efficient shoot regeneration system was required. Highest frequent regeneration was obtained when culturing V2 leaf discs on the basis medium supplemented NAA 0.1 mg/l and BA 1mg/l. Besides, the key factor in determining transgenic plants is consistently selective pressure. V2 variety of tobacco was sensitive to the antibiotics spectinomycin and streptomycin. At the concentration of 80 mg/l, spectinomycin inhibited completely shoot regeneration and plant growth. With streptomycin, the threshold is 125 mg/l. HIV-1 p24 and aadA genes were transferred to chloroplasts of the tobacco V2 variety by bombardment. Putatively transgenic plants were capable of resisting to streptomycin and spectinomycin up to 500 mg/l concentration. Through initial PCR testing, HIV-1 p24 was assumed present in the genome of the transgenics with the specific amplification band of 700 bp.
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Liu, Hai, Tatyana I. Kotova, and Michael P. Timko. "Increased Leaf Nicotine Content by Targeting Transcription Factor Gene Expression in Commercial Flue-Cured Tobacco (Nicotiana tabacum L.)." Genes 10, no. 11 (November 14, 2019): 930. http://dx.doi.org/10.3390/genes10110930.
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Nicotine, the most abundant pyridine alkaloid in cultivated tobacco (Nicotiana tabacum L.), is a potent inhibitor of insect and animal herbivory and a neurostimulator of human brain function. Nicotine biosynthesis is controlled developmentally and can be induced by abiotic and biotic stressors via a jasmonic acid (JA)-mediated signal transduction mechanism involving members of the APETALA 2/ethylene-responsive factor (AP2/ERF) and basic helix-loop-helix (bHLH) transcription factor (TF) families. AP2/ERF and bHLH TFs work combinatorically to control nicotine biosynthesis and its subsequent accumulation in tobacco leaves. Here, we demonstrate that overexpression of the tobacco NtERF32, NtERF221/ORC1, and NtMYC2a TFs leads to significant increases in nicotine accumulation in T2 transgenic K326 tobacco plants before topping. Up to 9-fold higher nicotine production was achieved in transgenics overexpressing NtERF221/ORC1 under the control of a constitutive GmUBI3 gene promoter compared to wild-type plants. The constitutive 2XCaMV35S promoter and a novel JA-inducible 4XGAG promoter were less effective in driving high-level nicotine formation. Methyljasmonic acid (MeJA) treatment further elevated nicotine production in all transgenic lines. Our results show that targeted manipulation of NtERF221/ORC1 is an effective strategy for elevating leaf nicotine levels in commercial tobacco for use in the preparation of reduced risk tobacco products for smoking replacement therapeutics.
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Sidik, Nik Marzuki, Roslina Mat Yazid, Dhalila Zafirah Mohd Dahlan, Babul Airianah Othman, and Ismanizan Ismail. "Accumulation of cadmium (Cd) in T1 transgenic tobacco seedlings expressing metallothionein gene from Eleusine indica." APRIL 2019 13, (04) 2019 (April 20, 2019): 599–604. http://dx.doi.org/10.21475/ajcs.19.13.04.p1630.
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Cadmium (Cd) contamination of urban and agricultural soils is toxic to humans, animals and may cause negative effects on plant growth and crop production. The existing conventional methods are found to be not efficient to remove Cd from contaminated soil. The present experiment reports the analysis of nine T1 lines of transgenic tobacco carrying metallothionein gene (eiMT1) from Eleusine indica, with potential for high efficiency to remediate Cd in contaminated soils. Thirty-days old tobacco plants were treated with different concentrations of CdNO3 (0, 50, 100 and, 150 µmol) for seven days and the accumulation of Cd in the whole seedling was quantitatively determined by using atomic absorption spectrometer (AAS). All transgenic tobacco lines showed greater tolerance and accumulated higher level of Cd than the wild type with lines 18D, 20D1 and, 18C were among the highest (678.7, 623.0 and 611.9 mgkg-1 Cd, respectively). Meanwhile, transgenic tobacco lines 18B1 and 20D1 showed higher expression of eiMT1 gene. These results suggest that the cadmium accumulation in transgenic tobacco did not strictly associate with the expression level of eiMT1 gene. However, expression of eiMT1 greatly required for higher accumulation of Cd in transgenic tobacco seedling.
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Tackaberry, Eilleen S., Fiona Prior, Margaret Bell, Monika Tocchi, Suzanne Porter, Jelica Mehic, Peter R. Ganz, Ravinder Sardana, Illimar Altosaar, and Anil Dudani. "Increased yield of heterologous viral glycoprotein in the seeds of homozygous transgenic tobacco plants cultivated underground." Genome 46, no. 3 (June 1, 2003): 521–26. http://dx.doi.org/10.1139/g03-008.
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The use of transgenic plants in the production of recombinant proteins for human therapy, including subunit vaccines, is being investigated to evaluate the efficacy and safety of these emerging biopharmaceutical products. We have previously shown that synthesis of recombinant glycoprotein B (gB) of human cytomegalovirus can be targeted to seeds of transgenic tobacco when directed by the rice glutelin 3 promoter, with gB retaining critical features of immunological reactivity (E.S. Tackaberry et al. 1999. Vaccine, 17: 30203029). Here, we report development of second generation transgenic plant lines (T1) homozygous for the transgene. Twenty progeny plants from two lines (A23T1-2 and A24T1-3) were grown underground in an environmentally contained mine shaft. Based on yields of gB in their seeds, the A23T1-2 line was then selected for scale-up in the same facility. Analyses of mature seeds by ELISA showed that gB specific activity in A23T1-2 seeds was over 30-fold greater than the best T0plants from the same transformation series, representing 1.07% total seed protein. These data demonstrate stable inheritance, an absence of transgene inactivation, and enhanced levels of gB expression in a homozygous second generation plant line. They also provide evidence for the suitability of using this environmentally secure facility to grow transgenic plants producing therapeutic biopharmaceuticals.Key words: transgenic tobacco seeds, homozygous second generation, glycoprotein B, human cytomegalovirus, vaccine, underground mine.
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Nowak, W., M. Gawłowska, A. Jarmołowski, and J. Augustyniak. "Effect of nuclear matrix attachment regions on transgene expression in tobacco plants." Acta Biochimica Polonica 48, no. 3 (September 30, 2001): 637–46. http://dx.doi.org/10.18388/abp.2001_3898.
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Matrix attachment regions (MARs) are thought to participate in the organization and segregation of independent chromosomal loop domains. Although there are several reports on the action of natural MARs in the context of heterologous genes in transgenic plants, in our study we tested a synthetic MAR (sMAR) with the special property of unpairing when under superhelical strain, for its effect on reporter gene expression in tobacco plants. The synthetic MAR was a multimer of a short sequence from the MAR 3' end of the immunoglobulin heavy chain (IgH) enhancer. This sMAR sequence was used to flank the beta-glucuronidase (GUS) reporter gene within the T-DNA of the binary vector pBI121. Vectors with or without the sMARs were then used to transform tobacco plants by Agrobacterium tumefaciens. Transgenic plants containing the sMAR sequences flanking the GUS gene exhibited higher levels of transgene expression compared with transgenic plants which lacked the sMARs. This effect was observed independently of the position of the sMAR at the 5' side of the reporter gene. However, variation of the detected transgene expression was significant in all transformed plant populations, irrespective of the construct used.
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Le Gall, Fabrice, Joseph-Marie Bové, and Monique Garnier. "Engineering of a Single-Chain Variable-Fragment (scFv) Antibody Specific for the Stolbur Phytoplasma (Mollicute) and Its Expression in Escherichia coli and Tobacco Plants." Applied and Environmental Microbiology 64, no. 11 (1998): 4566–72. http://dx.doi.org/10.1128/aem.64.11.4566-4572.1998.
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From a hybridoma cell line (2A10) producing an immunoglobulin G1 directed against the major membrane protein of the stolbur phytoplasma, we have engineered scFv (single-chain variable-fragment) antibodies from the variable heavy (VH) and light (VL) domains of the immunoglobulin. The scFv gene was cloned and expressed inEscherichia coli. The expressed protein of 30 kDa could be recovered from the periplasmic fraction of the bacterial cells and was shown to be fully functional toward its phytoplasmal antigen, since enzyme-linked immunosorbent assay or immunofluorescence (IF) detection of the stolbur phytoplasma antigen by the scFv was identical to that of the native immunoglobulin. The scFv gene was then cloned in plasmid pBG-dAb-BIN of Agrobacterium tumefaciens to transform tobacco plants. The transformed plants were screened by PCR and Northern blotting for the presence and expression of the transgene, respectively, and by IF for expression of the scFv. One transgenic tobacco line, 1A6, was selected for challenge inoculation with the stolbur phytoplasma. When grafted on a stolbur phytoplasma-infected tobacco rootstock, the transgenic tobacco shoots grew free of symptoms and flowered after 2 months, while normal tobacco shoots showed severe stolbur symptoms during the same period and eventually died.
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Kazan, Kemal, Fiona R. Murray, Ken C. Goulter, Danny J. Llewellyn, and John M. Manners. "Induction of Cell Death in Transgenic Plants Expressing a Fungal Glucose Oxidase." Molecular Plant-Microbe Interactions® 11, no. 6 (June 1998): 555–62. http://dx.doi.org/10.1094/mpmi.1998.11.6.555.
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Hydrogen peroxide (H2O2) has been implicated in the induction of plant defense genes and programmed cell death. Expression of a chimeric fungal glucose oxidase (GO) gene driven by a pathogen- and wound-inducible promoter was evaluated in transgenic tobacco and canola as a possible tool for engineering plant cell death and defense gene induction. Expression of this gene under the control of a peroxidase gene promoter resulted in the accumulation of relatively low levels of H2O2 in the young leaves of transgenic tobacco plants and this was not sufficient to cause any visible cell death and defense gene induction as measured by PR-1a mRNA induction. Older leaves of transgenic tobacco plants, however, exhibited visible necrotic lesions and constitutively expressed PR-1a mRNA when grown under high light conditions. Inoculation of cotyledons of control and transgenic canola with Leptosphaeria maculans resulted in rapid cotyledon senescence in the transgenic plants. Strong activators of the peroxidase promoter, i.e., wounding and inoculation of transgenic plants with Cercospora nicotianae, were not sufficient to trigger any additional visible cell death in transgenic tobacco plants, compared with controls. However, when exogenous glucose was supplied to transgenic tissue, massive cell death and PR-1a gene induction were observed in tobacco. Exogenously applied salicylic acid further increased the rate and extent of cell death. Our results suggest that efficacy of GO expression for the induction of cell death is restricted by glucose supply in the plants and are consistent with a role for salicylic acid in the potentiation of plant cell death by H2O2.
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Buziashvili, A. Yu, and A. I. Yemets. "Agrobacterium-mediated transformation of tobacco (Nicotiana tabacum L.) with human lactoferrin gene and analysis of transgenic lines." Faktori eksperimental'noi evolucii organizmiv 26 (September 1, 2020): 164–68. http://dx.doi.org/10.7124/feeo.v26.1261.
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Aim. Obtaining of tobacco lines (Nicotiana tabacum L.) stably transformed with human lactoferrin gene (hLf), analysis of transgenic lines. Methods. Agrobacterium-mediated transformation of tobacco was carried out with the use of pBin35LF plasmid containing human lactoferrin gene under control of 35S promoter of cauliflower mosaic virus (CaMV 35S) and selective npt II gene encoding neomicyne phosphotransferase II providing the resistance to kanamycin. The selection of transgenic lines was carried out for 3 months on MS medium supplemented with 100 mg/l of kanamycin. Integration of lactoferrin gene was confirmed with the use of PCR with primers specific to hLf gene. The investigation of karyotype of transgenic lines was carried out after the staining of the root cells with 1 % solution of acetoorseine. Results. After selection, 2 transgenic tobacco lines with confirmed integration of hLf gene were obtained. The transformation efficiency was 6.4 %. The chromosome number in transgenic and control lines was 2n=48. Conclusions. The obtained transgenic tobacco lines have the similar morphology and karyotype to control lines, so they could be considered to use as plant systems for the expression of recombinant human lactoferrin.
Keywords: human lactoferrin gene hLf, Nicotiana tabacum L., Agrobacterium-mediated transformation, PCR, chromosomes, transgenic plants.
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Synková, Helena, Karen Van Loven, Jana Pospíšilová, and Roland Valcke. "Photosynthesis of Transgenic Pssu-ipt Tobacco." Journal of Plant Physiology 155, no. 2 (August 1999): 173–82. http://dx.doi.org/10.1016/s0176-1617(99)80004-2.
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Sehnke, Paul C., and Robert J. Ferl. "Processing of Preproricin in Transgenic Tobacco." Protein Expression and Purification 15, no. 2 (March 1999): 188–95. http://dx.doi.org/10.1006/prep.1998.0993.
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Macek, T., M. Macková, D. Pavlíková, J. Száková, M. Truksa, A. Singh Cundy, P. Kotrba, N. Yancey, and W. H. Scouten. "Accumulation of Cadmium by Transgenic Tobacco." Acta Biotechnologica 22, no. 1-2 (May 2002): 101–6. http://dx.doi.org/10.1002/1521-3846(200205)22:1/2<101::aid-abio101>3.0.co;2-n.
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Barker, Hugh, Kara D. McGeachy, Eugene V. Ryabov, Uli Commandeur, Mike A. Mayo, and Michael Taliansky. "Evidence for RNA-mediated defence effects on the accumulation of Potato leafroll virus." Journal of General Virology 82, no. 12 (December 1, 2001): 3099–106. http://dx.doi.org/10.1099/0022-1317-82-12-3099.
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In plants infected with Potato leafroll virus (PLRV), or other luteoviruses, infection is very largely confined to cells in the vascular system. Even in tobacco plants transformed with PLRV full-length cDNA, in which all mesophyll cells should synthesize infectious PLRV RNA transcripts, only a minority of the mesophyll cells accumulate detectable amounts of virus. We have explored this phenomenon further by transforming a better PLRV host, Nicotiana benthamiana, with the same transgene, by superinfecting transformed plants with Potato virus Y and by producing tobacco plants in which cells contained both PLRV cDNA and DNA encoding the P1/HC-Pro genes of the potyvirus Tobacco etch virus. A greater proportion of cells in superinfected plants or in doubly transgenic plants accumulated PLRV than did in singly transgenic tobacco plants. However, most cells in these plants did not accumulate virus. To investigate restriction of the multiplication of viruses containing PLRV sequences, transgenic plants were infected with a chimeric virus that consisted of Tobacco mosaic virus (TMV) containing genes for either the coat protein (CP) of PLRV or jellyfish green fluorescent protein (GFP) in place of the TMV coat protein. The virus that encoded PLRV CP spread more slowly and accumulated less extensively than did the virus that expressed GFP. The results support the suggestion that an RNA-mediated form of resistance that resembles post-transcriptional gene silencing operates in non-vascular cells and may be part of the mechanism that restricts PLRV to vascular tissue in conventionally infected plants.
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Kalantidis, Kriton, Stavros Psaradakis, Martin Tabler, and Mina Tsagris. "The Occurrence of CMV-Specific Short RNAs in Transgenic Tobacco Expressing Virus-Derived Double-Stranded RNA is Indicative of Resistance to the Virus." Molecular Plant-Microbe Interactions® 15, no. 8 (August 2002): 826–33. http://dx.doi.org/10.1094/mpmi.2002.15.8.826.
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Expression or introduction of double-stranded (ds)RNA in eukaryotic cells can trigger sequence-specific gene silencing of transgenes, endogenes, and viruses. Transgenic plants producing dsRNAs with homology to viral sequences are likely to exhibit pathogen-derived resistance to the virus. Cucumber mosaic virus (CMV), a very widespread virus with over 1,000 host species, has the natural ability to suppress silencing in order to establish infection. Here, we report the generation of transgenic tobacco lines, where a DNA transgene containing an inverted repeat of CMV cDNA had been introduced. Expression of this DNA construct delivered an RNA transcript that is able to form an intramolecular double strand. Transgenic plants were challenged with CMV. Three categories of plants could be discriminated: susceptible plants, which typically reacted with milder symptoms than the wild-type control; a “recovery” phenotype, in which newly emerging leaves were free of symptoms; and plants that showed complete resistance. Northern analysis showed that the expression of CMV dsRNA caused, in some transgenic lines, the generation of short RNAs characteristic of posttranscriptional gene silencing. Those lines were CMV resistant. The correlation between the detection of short RNAs and virus resistance provides a molecular marker that makes it possible to predict success in attempts to engineer virus resistance by dsRNA.
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Han, Deguo, Yanjie Hou, Yufang Wang, Boxin Ni, Zitong Li, and Guohui Yang. "Overexpression of a Malus baccata WRKY transcription factor gene (MbWRKY5) increases drought and salt tolerance in transgenic tobacco." Canadian Journal of Plant Science 99, no. 2 (April 1, 2019): 173–83. http://dx.doi.org/10.1139/cjps-2018-0053.
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WRKY transcription factors are widely involved in abiotic stress responses in plants. However, their roles in the abiotic stresses of Malus plants are still not well known. In this study, a WRKY gene is isolated from Malus baccata (L.) Borkh. and designated as MbWRKY5. MbWRKY5 contains two WRKY domains and one Cys2-His2 (C2H2) zinc-finger motif, and was localized in the nucleus. The expression levels of MbWRKY5 were up-regulated by salinity, heat, cold, drought, and abscisic acid treatments in M. baccata seedlings. When MbWRKY5 was introduced into tobacco, an improvement in tolerance to drought and salt was achieved in transgenic plants. Under drought and salt treatments, transgenic plants had higher contents of chlorophyll, proline, glutathione, and ascorbate, and increased activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) than wild-type (WT) tobaccos. Compared with WT plants, overexpression of MbWRKY5 in transgenic tobacco also led to decreased levels of malondialdehyde and hydrogen peroxide (H2O2) under drought and salt stresses. Moreover, the MbWRKY5-OE tobaccos increased the expression levels of stress-related genes involved in oxidative stress response (NtPOD, NtSOD and NtCAT) and membrane protection (NtLEA5, NtERD10D, and NtP5CS), especially under drought and salt stresses. These results suggest that the MbWRKY5 gene plays a positive regulatory role in drought and salt stress responses.
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Gressel, Jonathan, and Hani Al-Ahmad. "Assessing and Managing Biological Risks of Plants Used for Bioremediation, Including Risks of Transgene Flow." Zeitschrift für Naturforschung C 60, no. 3-4 (April 1, 2005): 154–65. http://dx.doi.org/10.1515/znc-2005-3-402.
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Abstract The plants used for phytoremediation pose special biological risks, whether transgenic or not, as most of the species: (a) are semi-domesticated; (b) are introduced from other habitats; (c) can become established in the contaminated site; (d) can spread and displace native species, and/or; (e) may introgress transgenes into related species. The addition of transgenes can reduce the risks, e.g. to sterilize or render the species and hybrid offspring hypersensitive to environmental effects (heat, cold), or to a chemical that will cull the species. Various measures can contain transgenes used in phytoremediation species to prevent gene flow, but most containment technologies are both uni-directional (prevent either outflow or influx), and are inherently leaky, even a concept specifically utilizable for phytoremediation Ð grafting non-transgenic scions on bioremediating transgenic rootstocks. Containment mechanisms should be either stacked with each other or with “mitigator” genes. Transgenic mitigation (TM) has mitigator genes added in tandem to the desired primary transgene (genetically linked) and the mitigator genes confer traits that are positive or neutral to the desired species but are deleterious to hybrids, keeping them at very low frequencies. The concept was demonstrated in tobacco and oilseed rape with a dwarfing mitigator gene that enhanced the reproductive productivity (harvest index) when cultured alone, but eliminated it from mixed populations. Besides the mitigator genes previously proposed for crop species (sterility, no seed shattering, dwarfing, no secondary dormancy) there are genes especially appropriate for phytoremediation, e.g. overexpression of cytokinin oxidase (reduces cytokinin levels) conferring reduced shoot systems (unfitness to compete) with a more extensive root system that is better for extracting toxic wastes as well as no-flowering for vegetatively propagated species. Thus, biotechnology can be harnessed to reduce risks from both non-transgenic and transgenic phytoremediation species.
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Li, Jing-Jian, Xin Liu, Bo Zhao, and Wen-Lan Li. "NPR1 gene transformation as assessed by germ cell in situ transformation pathway into Siraitia grosvenorii." Bangladesh Journal of Botany 44, no. 2 (October 13, 2018): 245–50. http://dx.doi.org/10.3329/bjb.v44i2.38513.
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NPR1 gene was transformed into Siraitia grosvenorii (Swingle) C. Jeffrey ex. A.M. Lu and Zhi Y. Zhang by germ cell in situ transformation. Ovary injection, cutting chapiter, and chapiter spreading treatments were applied in this study. The transgenic plants were selected using hygromycin screening and confirmed by PCR testing, genome integrated with NPR1 gene in transgenic plants was analyzed by Southern hybridization. Results showed that three treatments could produce transgenic plants. Some of the transgenic plants were selected for tobacco mosaic virus inoculation testing, which showed a higher level of resistance to tobacco mosaic virus than non-transgenic controls.
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Gấm, Nguyễn Thị Hồng, Trần Thị Hương Giang, Bùi Phương Thảo, Nguyễn Văn Đoài, Nguyễn Thị Thơm, Bùi Văn Thắng, Phạm Bích Ngọc, and Chu Hoàng Hà. "Production of transgenic tobacco plants expressing GS1 gene for the increase ofnitrogen use efficiency." Vietnam Journal of Biotechnology 14, no. 3 (September 30, 2016): 507–13. http://dx.doi.org/10.15625/1811-4989/14/3/9865.
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Glutamine synthetase (GS, CE 6.3.1.2) is an enzyme that catalyzes the ATP-dependent condensation of glutamic acid with ammonia to yield glutamine. Glutamine synthetase is a key enzyme involved in the assimilation of inorganic nitrogen into organic forms. In plant cells, GS is present in both chloroplasts (GS2) and cytoplasm (GS1), in which GS1 can assimilate nitrogen source. In this study, one transgenic vector pBI121 carrying GS1 gene under the control of promoter 35S (pBI121::GS1) were successfully constructed. This vector containing G1S gene was transformed into tobacco leaves pieces via Agrobacterium tumefaciens strain C58. Five weeks after cultivation, there were 28 tobacco lines which had roots on the medium added kanamycin 50 mg/l. Then, the presence of G1S gene in these tobacco lines was tested from leaves in the next experiments. PCR and Southern blot confirmed that there are five tobacco lines carrying transferred GS1 gene. The effectiveness of nitrogen using in GS1 transgenic tobacco plants in vitro was evaluated. The tissue fresh weight, number and height of shoots forming buds and rooting ability of GS1 transgenic tobacco plants were greater than those of non-GM plants in the medium of low nitrogen concentration (0.1X - 0.2X). Assessment of crop growing in a greenhouse demonstrated that GS1 transgenic tobacco plants grow faster than non-transgenic ones. In detail, the increment of plant height after planting 03 months and 05 months in greenhouse is 43.55% and 33.29%, respectively. These results provide a scientific basis for the development of other genetically modified plants which enhanced nitrogen-use efficiency.
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Paschke, T. "Conference Report: 53rd Tobacco Science Research Conference (TSRC), September 12-15, 1999, in Montreal, Canada." Beiträge zur Tabakforschung International/Contributions to Tobacco Research 18, no. 6 (December 1, 1999): 255–57. http://dx.doi.org/10.2478/cttr-2013-0689.
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AbstractThe 53rd Tobacco Science Research Conference (TSRC), held in Montreal on September 12-15, 1999, was attended by about 300 scientists; 82 papers and 11 posters were presented. A keynote theme of the Conference was addressed in the Symposium on “Genetics and the Future of Tobacco”, with four contributions focussing on the effects of modern gene technology on tobacco growing, possible uses of transgenic tobacco and the main areas of research in this field, as well as consumer acceptance of transgenic products and regulatory issues, respectively.
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Chung, Bong-Nam, Tomas Canto, and Peter Palukaitis. "Stability of recombinant plant viruses containing genes of unrelated plant viruses." Journal of General Virology 88, no. 4 (April 1, 2007): 1347–55. http://dx.doi.org/10.1099/vir.0.82477-0.
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The stability of hybrid plant viruses that might arise by recombination in transgenic plants was examined using hybrid viruses derived from the viral expression vectors potato virus X (PVX) and tobacco rattle virus (TRV). The potato virus Y (PVY) NIb and HCPro open reading frames (ORFs) were introduced into PVX to generate PVX-NIb and PVX-HCPro, while the PVY NIb ORF was introduced into a vector derived from TRV RNA2 to generate TRV-NIb. All three viruses were unstable and most of the progeny viruses had lost the inserted sequences between 2 and 4 weeks post-inoculation. There was some variation in the rate of loss of part or all of the inserted sequence and the number of plants containing the deleted viruses, depending on the sequence, the host (Nicotiana tabacum vs Nicotiana benthamiana) or the vector, although none of these factors was associated consistently with the preferential loss of the inserted sequences. PVX-NIb was unable to accumulate in NIb-transgenic tobacco resistant to infection by PVY and also showed loss of the NIb insert from PVX-NIb in some NIb-transgenic tobacco plants susceptible to infection by PVY. These data indicate that such hybrid viruses, formed in resistant transgenic plants from a transgene and an unrelated virus, would be at a selective disadvantage, first by being targeted by the resistance mechanism and second by not being competitive with the parental virus.
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Frost, Donna, Heather Way, Paul Howles, Joanne Luck, John Manners, Adrienne Hardham, Jean Finnegan, and Jeff Ellis. "Tobacco Transgenic for the Flax Rust Resistance Gene L Expresses Allele-Specific Activation of Defense Responses." Molecular Plant-Microbe Interactions® 17, no. 2 (February 2004): 224–32. http://dx.doi.org/10.1094/mpmi.2004.17.2.224.
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Tobacco was transformed with three different alleles (L2, L6, and L10) of the flax rust resistance gene L, a member of the toll interleukin-1 receptor, nucleotide-binding site, leucine-rich repeat (TIR-NBS-LRR) class of plant disease resistance genes. L6 transgenics had a stunted phenotype, expressed several defense response genes constitutively, and had increased resistance to the fungus Cercospora nicotianae and the oomycete Phytophthora parasitica pv. nicotianae. L2 and L10 transgenics, with one exception for L10, did not express these phenotypes, indicating that the activation of tobacco defense responses is L6 allele-specific. The phenotype of the exceptional L10 transgenic plant was associated with the presence of a truncated L10 gene resulting from an aberrant T-DNA integration. The truncated gene consisted of the promoter, the complete TIR region, and 39 codons of the NBS domain fused in-frame to a tobacco retrotransposon-like sequence. A similar truncated L10 gene, constructed in vitro, was transiently expressed in tobacco leaves and gave rise to a strong localized necrotic reaction. Together, these results suggest that defense signaling properties of resistance genes can be expressed in an allele-specific and pathogen-independent manner when transferred between plant genera.
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Zhang, Zhifen, Yinping Guo, Kathleen Monfero Marasigan, Joann A. Conner, and Peggy Ozias-Akins. "Gene activation via Cre/lox-mediated excision in cowpea (Vigna unguiculata)." Plant Cell Reports 41, no. 1 (September 30, 2021): 119–38. http://dx.doi.org/10.1007/s00299-021-02789-z.
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Abstract Key message Expression of Cre recombinase by AtRps5apro or AtDD45pro enabled Cre/lox-mediated recombination at an early embryonic developmental stage upon crossing, activating transgenes in the hybrid cowpea and tobacco. Abstract Genetic engineering ideally results in precise spatiotemporal control of transgene expression. To activate transgenes exclusively in a hybrid upon fertilization, we evaluated a Cre/lox-mediated gene activation system with the Cre recombinase expressed by either AtRps5a or AtDD45 promoters that showed activity in egg cells and young embryos. In crosses between Cre recombinase lines and transgenic lines harboring a lox-excision reporter cassette with ZsGreen driven by the AtUbq3 promoter after Cre/lox-mediated recombination, we observed complete excision of the lox-flanked intervening DNA sequence between the AtUbq3pro and the ZsGreen coding sequence in F1 progeny upon genotyping but no ZsGreen expression in F1 seeds or seedlings. The incapability to observe ZsGreen fluorescence was attributed to the activity of the AtUbq3pro. Strong ZsGreen expression in F1 seeds was observed after recombination when ZsGreen was driven by the AtUbq10 promoter. Using the AtDD45pro to express Cre resulted in more variation in recombination frequencies between transgenic lines and crosses. Regardless of the promoter used to regulate Cre, mosaic F1 progeny were rare, suggesting gene activation at an early embryo-developmental stage. Observation of ZsGreen-expressing tobacco embryos at the globular stage from crosses with the AtRps5aproCre lines pollinated by the AtUbq3prolox line supported the early activation mode.
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Im, Yang Ju, Mi Seong Kim, Kwang Yeol Yang, Yong Hwan Kim, Kyoungwhan Back, and Baik Ho Cho. "Antisense expression of a ω-3 fatty acid desaturase gene in tobacco plants enhances susceptibility against pathogens." Canadian Journal of Botany 82, no. 3 (March 1, 2004): 297–303. http://dx.doi.org/10.1139/b03-151.
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Membrane lipids in higher plants contain a high proportion of trienoic fatty acids. ω-3 Fatty acid desaturases act on membrane lipids to catalyze the formation of trienoic acids. We isolated a wound-inducible Arabidopsis plastid ω-3 fatty acid desaturase (fad7) gene, and generated transgenic tobacco plants constitutively expressing the antisense fad7 RNA. Selected transgenic lines showed significant reductions in the content of trienoic fatty acids compared with control plants. The transgenic lines showed enhanced susceptibility against Tobacco mosaic virus infection, where necrotic lesions with brown halos developed much earlier and were larger in the transgenic lines than in control plants. After Tobacco mosaic virus infection, expression and protein accumulations of the wound-inducible protein kinase WIPK, as well as defense-response gene expressions such as lipoxygenase (lox) and defensin (pdf1.2), were retarded in the transgenic lines compared with control plants. Increased susceptibility of the transgenic lines was also demonstrated by infections with Pseudomonas syringae pv. tabaci (van Hall) Ash et al., which caused wildfire disease, and with a powdery mildew fungus (Erysiphe cichoracearum DC). These findings support the concept that trienoic fatty acids are involved in plant defense signaling.Key words: ω-3 fatty acid desaturase, linolenic acid, Nicotiana tabacum 'Xanthi', Pseudomonas syringae pv. tabaci, powdery mildew fungus, Tobacco mosaic virus.
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Khan, Muhammad Hassaan, Georg Jander, Zahid Mukhtar, Muhammad Arshad, Muhammad Sarwar, and Shaheen Asad. "Comparison of in Vitro and in Planta Toxicity of Vip3A for Lepidopteran Herbivores." Journal of Economic Entomology 113, no. 6 (October 20, 2020): 2959–71. http://dx.doi.org/10.1093/jee/toaa211.
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Abstract Agricultural pest infestation is as old as domestication of food crops and contributes a major share to the cost of crop production. In a transgenic pest control approach, plant production of Vip3A, an insecticidal protein from Bacillus thuringiensis, is effective against lepidopteran pests. A synthetic Vip3A gene was evaluated for efficacy against Spodoptera litura Fabricius (Lepidoptera: Noctuidae; cotton leafworm), Spodoptera exigua Hübner (Lepidoptera: Noctuidae; beet armyworm), Spodoptera frugiperda Smith (Lepidoptera: Noctuidae; fall armyworm), Helicoverpa armigera Hübner (Lepidoptera: Noctuidae; cotton bollworm), Helicoverpa zea Boddie (Lepidoptera: Noctuidae; corn earworm), Heliothis virescens Fabricius (Lepidoptera: Noctuidae; tobacco budworm), and Manduca sexta L. (Lepidoptera: Sphingidae; tobacco hornworm) in tobacco. In artificial diet assays, the concentration required to achieve 50% mortality was highest for H. zea followed by H. virescens > S. exigua > H. armigera > M. sexta > S. frugiperda > S. litura. By contrast, in bioassays with detached leaves from Vip3A transgenic tobacco, the time until 50% lethality was M. sexta > H. virescens > S. litura > H. zea > H. armigera > S. exigua. There was no significant correlation between the artificial diet and transgenic plant bioassay results. Notably, the two insect species that are best-adapted for growth on tobacco, M. sexta and H. virescens, showed the greatest time to 50% mortality on Vip3A-transgenic tobacco. Together, our results suggest that artificial diet assays may be a poor predictor of Vip3A efficacy in transgenic plants, lepidopteran species vary in their sensitivity to Vip3A in diet-dependent manner, and host plant adaptation of the targeted herbivores should be considered when designing transgenic plants for pest control.