Stable genetic transformation of Vigna mungo L. Hepper via Agrobacterium tumefaciens
TL;DR: The production of morphologically normal and fertile transgenic plants from cotyledonary-node explants inoculated with Agrobacterium tumefaciens carrying binary vector pCAMBIA2301, the latter of which contains a neomycin phosphotransferase (nptII) gene and a β-glucuronidase (GUS) gene (uidA) interrupted with an intron is reported.
Abstract: Vigna mungo is one of the large-seeded grain legumes that has not yet been transformed. We report here for the first time the production of morphologically normal and fertile transgenic plants from cotyledonary-node explants inoculated with Agrobacterium tumefaciens carrying binary vector pCAMBIA2301, the latter of which contains a neomycin phosphotransferase (nptII) gene and a β-glucuronidase (GUS) gene (uidA) interrupted with an intron. The transformed green shoots, selected and rooted on medium containing kanamycin, tested positive for nptII and uidA genes by polymerase chain reaction (PCR) analysis. These shoots were established in soil and grown to maturity to collect the seeds. Mechanical wounding of the explants prior to inoculation with Agrobacterium, time lag in regeneration due to removal of the cotyledons from explants and a second round of selection at the rooting stage were found to be critical for transformation. Analysis of T0 plants showed the expression and integration of uidA into the plant genome. GUS activity in leaves, roots, flowers, anthers and pollen grains was detected by histochemical assay. PCR analysis of T1 progeny revealed a Mendelian transgene inheritance pattern. The transformation frequency was 1%, and 6–8 weeks were required for the generation of transgenics.
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TL;DR: Transgenic cowpeas that transmit the transgenes to their progeny can be recovered at a rate of one fertile plant per thousand explants and pave the way for the introduction of new traits into cowpea, which will include those with potential to protect against insect pests.
Abstract: Cowpeas are nutritious grains that provide the main source of protein, highly digestible energy and vitamins to some of the world's poorest people. The demand for cowpeas is high but yields remain critically low, largely because of insect pests. Cowpea germplasm contains little or no resistance to major insect pests and a gene technology approach to adding insect protection traits is now a high priority. We have adapted features of several legume and other transformation systems and reproducibly obtained transgenic cowpeas that obey Mendelian rules in transmitting the transgene to their progeny. Critical parameters in this transformation system include the choice of cotyledonary nodes from developing or mature seeds as explants and a tissue culture medium devoid of auxins in the early stages, but including the cytokinin BAP at low levels during shoot initiation and elongation. Addition of thiol-compounds during infection and co-culture with Agrobacterium and the choice of the bar gene for selection with phosphinothricin were also important. Transgenic cowpeas that transmit the transgenes to their progeny can be recovered at a rate of one fertile plant per thousand explants. These results pave the way for the introduction of new traits into cowpea and the first genes to be trialled will include those with potential to protect against insect pests.
146 citations
Cites methods from "Stable genetic transformation of Vi..."
...We therefore opted for regeneration via organogenesis, which has been a successful platform for transformation protocols in other plants, including legumes (Schroeder et al. 1993; Olhoft and Somers 2001; Saini et al. 2003; Sarmah et al. 2004)....
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TL;DR: The state of the art of gene technology for genetic improvement of those grain legumes of major importance to developing countries are reviewed and protocols are evaluated for their reproducibility, efficiency and robustness.
134 citations
TL;DR: A reproducible Agrobacterium tumefaciens-mediated genetic transformation system for the production of fertile transgenic plants ofcowpea that transmits transgenes into progeny in Mendelian fashion has been developed and can be used to introduce agronomically desired genes in cowpea for its genetic improvement.
82 citations
TL;DR: Results indicate that co-expression of stress responsive TFs can activate multiple CT pathways, and this strategy can be employed to improve abiotic stress tolerance in crop plants.
Abstract: Drought, salinity and extreme temperatures are the most common abiotic stresses, adversely affecting plant growth and productivity. Exposure of plants to stress activates stress signalling pathways that induce biochemical and physiological changes essential for stress acclimation. Stress tolerance is governed by multiple traits, and importance of a few traits in imparting tolerance has been demonstrated. Under drought, traits linked to water mining and water conservation, water use efficiency and cellular tolerance (CT) to desiccation are considered to be relevant. In this study, an attempt has been made to improve CT in drought hardy crop, peanut (Arachis hypogaea L., cv. TMV2) by co-expressing stress-responsive transcription factors (TFs), AtDREB2A, AtHB7 and AtABF3, associated with downstream gene expression. Transgenic plants simultaneously expressing these TFs showed increased tolerance to drought, salinity and oxidative stresses compared to wild type, with an increase in total plant biomass. The transgenic plants exhibited improved membrane and chlorophyll stability due to enhanced reactive oxygen species scavenging and osmotic adjustment by proline synthesis under stress. The improvement in stress tolerance in transgenic lines were associated with induced expression of various CT related genes like AhGlutaredoxin, AhAldehyde reductase, AhSerine threonine kinase like protein, AhRbx1, AhProline amino peptidase, AhHSP70, AhDIP and AhLea4. Taken together the results indicate that co-expression of stress responsive TFs can activate multiple CT pathways, and this strategy can be employed to improve abiotic stress tolerance in crop plants.
72 citations
TL;DR: The α-amylase inhibitor gene isolated from phaseolus vulgaris seeds was introduced into chickpea cultivar K850 through Agrobacterium- mediated transformation and revealed a significant reduction in the survival rate of bruchid weevil.
Abstract: Chickpea is the world’s third most important pulse crop and India produces 75% of the world’s supply. Chickpea seeds are attacked byCallosobruchus maculatus andC. chinensis which cause extensive damage. The α-amylase inhibitor gene isolated fromPhaseolus vulgaris seeds was introduced into chickpea cultivar K850 throughAgrobacterium- mediated transformation. A total of 288 kanamycin resistant plants were regenerated. Only 0.3% of these were true transformants. Polymerase chain reaction (PCR) analysis and Southern hybridization confirmed the presence of 4.9 kb α-amylase inhibitor gene in the transformed plants. Western blot confirmed the presence of α-amylase inhibitor protein. The results of bioassay study revealed a significant reduction in the survival rate of bruchid weevilC. maculatus reared on transgenic chickpea seeds. All the transgenic plants exhibited a segregation ratio of 3:1.
68 citations
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15 Jan 2001
TL;DR: Molecular Cloning has served as the foundation of technical expertise in labs worldwide for 30 years as mentioned in this paper and has been so popular, or so influential, that no other manual has been more widely used and influential.
Abstract: Molecular Cloning has served as the foundation of technical expertise in labs worldwide for 30 years. No other manual has been so popular, or so influential. Molecular Cloning, Fourth Edition, by the celebrated founding author Joe Sambrook and new co-author, the distinguished HHMI investigator Michael Green, preserves the highly praised detail and clarity of previous editions and includes specific chapters and protocols commissioned for the book from expert practitioners at Yale, U Mass, Rockefeller University, Texas Tech, Cold Spring Harbor Laboratory, Washington University, and other leading institutions. The theoretical and historical underpinnings of techniques are prominent features of the presentation throughout, information that does much to help trouble-shoot experimental problems. For the fourth edition of this classic work, the content has been entirely recast to include nucleic-acid based methods selected as the most widely used and valuable in molecular and cellular biology laboratories. Core chapters from the third edition have been revised to feature current strategies and approaches to the preparation and cloning of nucleic acids, gene transfer, and expression analysis. They are augmented by 12 new chapters which show how DNA, RNA, and proteins should be prepared, evaluated, and manipulated, and how data generation and analysis can be handled. The new content includes methods for studying interactions between cellular components, such as microarrays, next-generation sequencing technologies, RNA interference, and epigenetic analysis using DNA methylation techniques and chromatin immunoprecipitation. To make sense of the wealth of data produced by these techniques, a bioinformatics chapter describes the use of analytical tools for comparing sequences of genes and proteins and identifying common expression patterns among sets of genes. Building on thirty years of trust, reliability, and authority, the fourth edition of Mol
215,169 citations
TL;DR: In vivo redox biosensing resolves the spatiotemporal dynamics of compartmental responses to local ROS generation and provide a basis for understanding how compartment-specific redox dynamics may operate in retrograde signaling and stress 67 acclimation in plants.
Abstract: In experiments with tobacco tissue cultured on White's modified medium (basal meditmi hi Tnhles 1 and 2) supplemenk'd with kiticthi and hidoleacctic acid, a slrikin^' fourlo (ive-told intTease iu yield was ohtaitu-d within a three to Tour week j^rowth period on addition of an aqtteotis exlrarl of tobacco leaves (Fi^'ures 1 and 2). Subse(iueutly it was found Ihiit this jnoniotiou oi' f^rowih was due mainly though nol entirely to inorj^auic rather than organic con.stitttenls in the extract. In the isolation of Rrowth factors from plant tissues and other sources inorj '̂anic salts are fre(|uently carried along with fhe organic fraclioits. When tissue cultures are used for bioassays, therefore, il is necessary lo lake into account increases in growth which may result from nutrient elements or other known constituents of the medium which may he present in the te.st materials. To minimize interference trom rontaminaitis of this type, an altempt has heen made to de\\eh)p a nieditmi with such adequate supplies of all re(iuired tnineral nutrients and cotntnott orgattic cottslitueitls that no apprecial»le change in growth rate or yield will result from the inlroduclion of additional amounts in the range ordinarily expected to be present in tnaterials to be assayed. As a point of referetice for this work some of the culture media in mc)st common current use will he cotisidered briefly. For ease of comparis4)n Iheir mineral compositions are listed in Tables 1 and 2. White's nutrient .solution, designed originally for excised root cultures, was based on Uspeuski and Uspetiskaia's medium for algae and Trelease and Trelease's micronutrieni solution. This medium also was employed successfully in the original cttltivation of callus from the tobacco Iiybrid Nicotiana gtauca x A', tanijadorffii, atitl as further modified by White in 194̂ ^ and by others it has been used for the
63,098 citations
01 Jan 1962
16,251 citations
"Stable genetic transformation of Vi..." refers methods in this paper
...…washed four to five times with sterile distilled water, then soaked in sterile distilled water in a conical flask (250 ml) plugged with non- absorbent cotton wrapped in cheese cloth for 16 h or cultured on MS (Murashige and Skoog 1962) basal medium (MSB) for 4 days at 25€2 C under light conditions....
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...They were subsequently washed four to five times with sterile distilled water, then soaked in sterile distilled water in a conical flask (250 ml) plugged with non- absorbent cotton wrapped in cheese cloth for 16 h or cultured on MS (Murashige and Skoog 1962) basal medium (MSB) for 4 days at 25€2 C under light conditions....
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TL;DR: GUS is very stable, and tissue extracts continue to show high levels of GUS activity after prolonged storage, and Histochemical analysis has been used to demonstrate the localization of gene activity in cells and tissues of transformed plants.
Abstract: We have used the Escherichia coli beta-glucuronidase gene (GUS) as a gene fusion marker for analysis of gene expression in transformed plants. Higher plants tested lack intrinsic beta-glucuronidase activity, thus enhancing the sensitivity with which measurements can be made. We have constructed gene fusions using the cauliflower mosaic virus (CaMV) 35S promoter or the promoter from a gene encoding the small subunit of ribulose bisphosphate carboxylase (rbcS) to direct the expression of beta-glucuronidase in transformed plants. Expression of GUS can be measured accurately using fluorometric assays of very small amounts of transformed plant tissue. Plants expressing GUS are normal, healthy and fertile. GUS is very stable, and tissue extracts continue to show high levels of GUS activity after prolonged storage. Histochemical analysis has been used to demonstrate the localization of gene activity in cells and tissues of transformed plants.
9,765 citations
"Stable genetic transformation of Vi..." refers methods in this paper
...Enzyme assay The GUS activity in tissues was determined by a histochemical assay according to Jefferson et al. (1987)....
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TL;DR: The nutrient requirements of suspension cultures from soybean root have been investigated, and a simple medium consisting of mineral salts, sucrose, vitamins and 2,4-dichlorophenoxyacetic acid (2, 4- d) has been designed.
9,342 citations
"Stable genetic transformation of Vi..." refers methods in this paper
...The explants were cultured in a vertically upright position with the hypocotyl cut end slightly embedded in medium containing MS salts, B5 vitamins (Gamborg et al.1968), 3% (w/v) sucrose (MSB) and different concentrations of BA (0.5–10 M), pH 5.8, solidified with 0.7% agar (Hi Media, Mumbai)....
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