Which of the following is not a direct method of gene transger in plants:

Options

A. Agrobacterium tumefaciens
B. Gene gun method
C. Biolistic method
D. Electroporation

Answer

To solve the question "Which of the following is not a direct method of gene transfer in plants?", we will analyze the options provided: Agrobacterium tumefaciens, gene gun method, biolistic method, and electroporation.

### Step-by-Step Solution:

1. **Understanding Gene Transfer Methods**:
- Gene transfer methods can be classified into direct and indirect methods. Direct methods involve the physical introduction of DNA into the plant cells, while indirect methods involve the use of vectors or other organisms to transfer the DNA.

2. **Analyzing Each Option**:
- **Agrobacterium tumefaciens**: This is a bacterium that naturally transfers DNA to plant cells. It does this by infecting the plant and inducing tumor formation (T-DNA transfer). This process is considered **indirect** because the DNA is first incorporated into the bacterium and then transferred to the plant.

- **Gene Gun Method**: Also known as the biolistic method, this technique involves coating microscopic particles (like gold or tungsten) with DNA and then shooting them into plant cells. This is a **direct method** of gene transfer.

- **Biolistic Method**: As mentioned, this is synonymous with the gene gun method and is also a **direct method** of gene transfer.

- **Electroporation**: In this method, an electric field is applied to plant cells to create temporary pores in the cell membrane, allowing DNA to enter. This is also a **direct method** of gene transfer.

3. **Conclusion**:
- Among the options provided, **Agrobacterium tumefaciens** is the only method that is not a direct method of gene transfer in plants. Therefore, the answer to the question is **Agrobacterium tumefaciens**.

### Final Answer:
**Agrobacterium tumefaciens** is not a direct method of gene transfer in plants.

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