The frist transgenic tobacco plant was resistant to the weedicide glyphosate. The gene for glyphosate resistance was derived from :

Options

A. E.coil
B. Bacillus thruingiensis
C. Salmonella typhimurium
D. Salmaonella hygroscopicus

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the origin of the gene responsible for glyphosate resistance in the first transgenic tobacco plant.

2. **Historical Context**: The first transgenic tobacco plant was created in 1983 and was engineered to be resistant to glyphosate, a common herbicide.

3. **Mechanism of Glyphosate**: Glyphosate works by inhibiting a specific enzyme called enolpyruvylshikimate-3-phosphate synthase (EPSPS), which is crucial for the biosynthesis of aromatic amino acids in plants.

4. **Source of Resistance**: The gene that confers resistance to glyphosate was derived from a specific bacterium. This bacterium possesses a version of the EPSPS enzyme that is not inhibited by glyphosate.

5. **Identifying the Bacterium**: The bacterium from which the glyphosate resistance gene was derived is *Salmonella typhimurium*. This bacterium has a plasmid that contains the gene responsible for the glyphosate resistance.

6. **Conclusion**: Therefore, the correct answer to the question is that the gene for glyphosate resistance in the first transgenic tobacco plant was derived from *Salmonella typhimurium*.

**Final Answer**: The gene for glyphosate resistance was derived from *Salmonella typhimurium*.

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