Soybeans are typically genetically modified through a process called transgenics, which involves transferring specific genes from one organism to another.
This process allows scientists to introduce desirable traits, such as herbicide resistance, directly into the soybean's genetic makeup. Here's a more detailed look at how this is achieved:
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Identifying Desirable Genes: Scientists first identify genes that provide advantageous traits. For example, a gene from a bacterium that confers resistance to a specific herbicide, like glyphosate (Roundup).
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Gene Isolation and Preparation: Once identified, the desired gene is isolated and modified for insertion into the soybean genome. This often involves adding a promoter sequence to ensure the gene is expressed in the plant.
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Gene Transfer: Several methods can be used to transfer the gene into soybean cells:
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Agrobacterium-mediated Transformation: This is a common method. Agrobacterium tumefaciens, a bacterium, is used as a vector to carry the desired gene into the plant cell. The bacterium naturally infects plants and inserts its DNA into the plant's genome. Scientists modify the Agrobacterium to carry the desired gene, which is then transferred into the soybean cells during infection.
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Gene Gun (Biolistic Method): This method involves coating tiny gold or tungsten particles with the desired gene and then "shooting" these particles into plant cells using a gene gun. The particles penetrate the cell walls and membranes, delivering the gene into the nucleus.
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Selection and Regeneration: After gene transfer, the soybean cells are grown in a selective medium that allows only the transformed cells (those that have successfully incorporated the new gene) to survive. These selected cells are then regenerated into whole plants using tissue culture techniques.
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Testing and Breeding: The resulting genetically modified soybean plants are tested to ensure that the desired trait is expressed and stable. These plants are then bred to produce new generations of genetically modified soybeans with the desired characteristics.
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Example: Herbicide Resistance: A common example is glyphosate-resistant soybeans (Roundup Ready). A gene from a bacterium that makes the plant resistant to glyphosate is inserted into the soybean genome. This allows farmers to spray glyphosate to control weeds without harming the soybean crop.
In summary, soybeans are genetically modified using transgenics to introduce specific genes that provide desirable traits such as herbicide resistance. This is achieved through techniques like Agrobacterium-mediated transformation or the gene gun method, followed by selection, regeneration, and breeding.
