Which one of the following bacteria is used for production of transgenic plants ?
(a) Escherichia coli
(b) Bacillus subtillis
(c) Staphyloccoccus aureus
(d) Agrobacterium tumefaciens

Options

A. Escherichia coli
B. Bacillus subtillis
C. Staphyloccoccus aureus
D. Agrobacterium tumefaciens

Answer

To solve the question "Which one of the following bacteria is used for the production of transgenic plants?" we will analyze the options provided:

1. **Escherichia coli**: This bacterium is commonly used in molecular biology for cloning and expressing genes, but it is not used for the direct production of transgenic plants.

2. **Bacillus subtilis**: This is a soil bacterium that is often used in biotechnology and as a probiotic, but it does not play a role in the production of transgenic plants.

3. **Staphylococcus aureus**: This bacterium is known for causing infections in humans and is not involved in plant genetic engineering.

4. **Agrobacterium tumefaciens**: This bacterium is well-known for its ability to transfer DNA to plant cells, which is a crucial step in the creation of transgenic plants. It contains a plasmid known as the Ti (tumor-inducing) plasmid, which can integrate genes into the plant genome.

Given this analysis, the correct answer is:

**(d) Agrobacterium tumefaciens**

### Step-by-Step Solution:
1. **Identify the Purpose**: The question asks which bacterium is used for producing transgenic plants.
2. **Review Each Option**: Analyze each of the four bacteria listed to determine their relevance to transgenic plant production.
3. **Focus on Agrobacterium tumefaciens**: Recognize that Agrobacterium tumefaciens is specifically known for its role in transferring genes to plants.
4. **Understand the Mechanism**: Acknowledge that Agrobacterium tumefaciens uses its Ti plasmid to integrate foreign DNA into the plant genome, which is essential for creating transgenic plants.
5. **Select the Correct Answer**: Conclude that the correct answer is (d) Agrobacterium tumefaciens.