DNA - viruses Which of the following owing is not applicable to Agrobacterium tumifaciens ?

Options

A. Pathogen of several dicot plants
B. It has ability to transform normal plant cells
C. Delivers gene of our interest
D. Ti plasmid of it is always pathogenic to plants without any exception

Answer

To determine which statement is not applicable to Agrobacterium tumefaciens, we will analyze each option provided.

### Step-by-Step Solution:

1. **Understand Agrobacterium tumefaciens**:
- It is a bacterium known for its ability to transfer DNA to plant cells, causing crown gall disease in dicotyledonous plants.

2. **Evaluate Option 1**:
- **Statement**: "Pathogen of several dicot plants."
- **Analysis**: Agrobacterium tumefaciens is indeed a pathogen of many dicot plants, causing crown gall disease.
- **Conclusion**: This statement is applicable.

3. **Evaluate Option 2**:
- **Statement**: "It has the ability to transform normal plant cells."
- **Analysis**: Agrobacterium tumefaciens can transform normal plant cells into tumor cells by transferring part of its DNA (T-DNA) into the plant genome.
- **Conclusion**: This statement is also applicable.

4. **Evaluate Option 3**:
- **Statement**: "Delivers gene of our interest."
- **Analysis**: The Ti plasmid in Agrobacterium tumefaciens can be used as a vector to deliver genes of interest into plant cells.
- **Conclusion**: This statement is applicable as well.

5. **Evaluate Option 4**:
- **Statement**: "Ti Plasmid is always pathogenic to plants without any exception."
- **Analysis**: While the Ti plasmid is associated with pathogenicity, it is not always pathogenic. It can be modified to carry genes without causing disease, thus not all Ti plasmids are pathogenic.
- **Conclusion**: This statement is **not applicable** to Agrobacterium tumefaciens.

### Final Answer:
The option that is not applicable to Agrobacterium tumefaciens is: **"Ti Plasmid is always pathogenic to plants without any exception."**

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