Efficient production of transgenic soybean (Glycine max (L) Merrill) plants mediated via whisker-supersonic (WSS) method (original) (raw)
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Breeding Science, 2005
In an attempt to increase the efficiency of soybean transformation by particle bombardment, we examined the effects of bombardment parameters such as gold particle size, target distance, acceleration pressure, amount of DNA per bombardment, and number of bombardments. Transgene delivery to embryogenic tissue grown in suspension culture was evaluated by monitoring the transient expression of a gene for a modified form of jellyfish green fluorescent protein [sGFP(S65T)]. Optimal transient expression of sGFP(S65T) was obtained when the tissue was bombarded twice at an acceleration pressure of 7.6 MPa (1,100 psi) and a distance of 6 cm with gold particles that were 0.6 µm in diameter and coated with 0.8 µg of DNA. Application of these optimized conditions proved effective for the generation of stable transgenic soybean plants. Stable transgene integration in the transformants was confirmed by Southern blot analysis. The average transformation efficiency achieved with the optimized protocol was siginificantly higher than that with the conventional protocol.
Euphytica, 2011
An Agrobacterium-mediated transformation procedure for soybean [Glycine max L. Merrill] proliferating somatic embryos is here described. The Agrobacterium tumefaciens LBA4404 strain harboring pTOK233, pCAMBIA1390-olp or pH7WG2Dwrky plasmids was used to mediate gene transfer into the plant genome. Prior to Agrobacterium inoculation, proliferative soybean embryogenic clusters were microwounded by DNA-free tungsten particle bombardment. Three independent transformation experiments were performed. In Experiment I, 26 transgenic plants were obtained from a unique clone of cv Bragg, while 580 plants were recovered from 105 clones of cv IAS5. In Experiment II, a single hygromycin-resistant clone of cv BRSMG68 Vencedora was recovered and gave rise to five plants. In Experiment III, 19 plants of cv Bragg and 48 plants of IAS5 were recovered, representing five and 14 independent transformation events, respectively. PCR and Southern analyses confirmed the transgenes’ integration into plant genomes. Transgenic plants were fertile. They flowered, set pods and seeds. Transgene segregation in two T1 progenies fits the Mendelian pattern (3:1 transgenic:non-transgenic plants). This is the first report of transgenic fertile soybean plants obtained from somatic embryogenic tissues transformed by the system that combines DNA-free particle bombardment and Agrobacterium.
2002
This work describes the production of transgenic, fertile plants of soybean [Glycine max (L.) Merrill]. The transformation method combines the advantages of somatic embryogenesis with the efficiency of particle bombardment of tissues that have a great capacity for in vitro proliferation and regeneration. The results described here represent the first report of transformation of soybean cultivars recommended for commercial growing in South Brazil using somatic embryogenesis, and may open the field for the improvement of this crop in this country by genetic engineering.
Transformation of Soybean and Use of Transgenic Lines in Basic and Applied Research
Research on transgenic soybean ensures the generation of new data for basic and applied research. Successful transformation of soybean was achieved by both particle bombardment and Agrobacterium-based methods. The introduction of transgenes is a powerful tool for increasing resistance to biotic and abiotic stresses. Thus, resistance to viral and fungal infection, nematodes and insects, tolerance to herbicides as well as drought and high temperature can be increased using transformation. In the case of the industrial use of soybean oil, the alteration of fatty acid composition widened the range of potential applications. Yield quality was also improved by changing the amino acid composition in order to fulfil the requirement necessary for soybean to be used as food or feed. The function-, organ-or developmental stage-specific expression changes of several genes were studied in transgenic soybean. Suppressed or increased expression of genes allowed the determination of the possible regulatory or functional role of their products. Up to now the desired traits have been manipulated in soybean mainly by modification of the expression of structural genes. However, in the case of abiotic stress tolerance, determined by several genes, even more success could be achieved in the future if the expression of whole regulons might be changed by the genetic manipulation of the corresponding transcription factors.
High-efficiency transformation by biolistics of soybean, common bean and cotton transgenic plants
Nature Protocols, 2008
This protocol describes a method for high-frequency recovery of transgenic soybean, bean and cotton plants, by combining resistance to the herbicide imazapyr as a selectable marker, multiple shoot induction from embryonic axes of mature seeds and biolistics techniques. This protocol involves the following stages: plasmid design, preparation of soybean, common bean and cotton apical meristems for bombardment, microparticle-coated DNA bombardment of apical meristems and in vitro culture and selection of transgenic plants. The average frequencies (the total number of fertile transgenic plants divided by the total number of bombarded embryonic axes) of producing germline transgenic soybean and bean and cotton plants using this protocol are 9, 2.7 and 0.55%, respectively. This protocol is suitable for studies of gene function as well as the production of transgenic cultivars carrying different traits for breeding programs. This protocol can be completed in 7-10 months.
Genetics and Molecular Biology, 2012
Transgenic plants represent an invaluable tool for molecular, genetic, biochemical and physiological studies by gene overexpression or silencing, transposon-based mutagenesis, protein sub-cellular localization and/or promoter characterization as well as a breakthrough for breeding programs, allowing the production of novel and genetically diverse genotypes. However, the stable transformation of soybean cannot yet be considered to be routine because it depends on the ability to combine efficient transformation and regeneration techniques. Two methods have been used with relative success to produce completely and stably transformed plants: particle bombardment and the Agrobacterium tumefaciens system. In addition, transformation by Agrobacterium rhizogenes has been used as a powerful tool for functional studies. Most available information on gene function is based on heterologous expression systems. However, as the activity of many promoters or proteins frequently depends on specific interactions that only occur in homologous backgrounds, a final confirmation based on a homologous expression system is desirable. With respect to soybean biotech improvement, transgenic lines with agronomical, nutritional and pharmaceutical traits have been obtained, including herbicide-tolerant soybeans, which represented the principal biotech crop in 2011, occupying 47% of the global biotech area.
Molecular control of gene co-suppression in transgenic soybean via particle bombardment
Journal of biochemistry and molecular biology, 2006
Molecular co-suppression phenomena are important to consider in transgene experiments. Embryogenic cells were obtained from immature cotyledons and engineered with two different gene constructs (pHV and pHVS) through particle bombardment. Both constructs contain a gene conferring resistance to hygromycin (hpt) as a selective marker and a modified glycinin (11S globulin) gene (V3-1) as a target. sGFP(S65T) as a reporter gene was, however, inserted into the flanking region of the V3-1 gene (pHVS). Fluorescence microscopic screening after the selection of hygromycin, identified clearly the expression of sGFP(S65T) in the transformed soybean embryos bombarded with the pHVS construct. Stable integration of the transgenes was confirmed by polymerase chain reaction (PCR) and Southern blot analysis. Seeds of transgenic plants obtained from the pHV construct frequently lacked an accumulation of endogenous glycinin, which is encoded by homologous genes to the target gene V3-1. Most of the tra...
In Vitro Cellular & Developmental Biology - Plant, 2018
In the present study, Agrobacterium tumefaciens-mediated transformation of Glycine max (L.) Merr. (soybean) cv. DS-9712 using half-seed explants was optimized for eight different parameters, including seed imbibition, medium pH, infection mode (sonication and vacuum infiltration), co-cultivation conditions, concentrations of supplementary compounds, and selection. Using this improved protocol, maximum transformation of 14% and regeneration efficiencies of 45% were achieved by using explants prepared from mature seeds imbibed for 36 h, infected with A. tumefaciens strain EHA105 at an optical density (OD 600) of 0.8, suspended in pH 5.4 medium containing 0.2 mM acetosyringone and 450 mg L −1 L-cysteine, followed by sonication for 10 s, vacuum infiltration for 2 min, and co-cultivated for 3 d on 35 mg L −1 kanamycin-containing medium. Independent transgenic lines were confirmed to be transgenic after ß-glucuronidase histochemical assays, polymerase chain reaction, and southern hybridization analysis. The protocol developed in the present study showed high regeneration efficiency within a relatively short time of 76 d. This rapid and efficient protocol might overcome some hurdles associated with the genetic manipulation of soybean.