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 answer the question regarding which statement is not applicable to Agrobacterium tumefaciens, let's analyze the options step by step:

### Step 1: Understanding Agrobacterium tumefaciens
Agrobacterium tumefaciens is a soil bacterium known for its ability to transfer DNA to plant cells, particularly affecting dicotyledonous (dicot) plants. It is primarily responsible for causing crown gall disease in these plants.

**Hint:** Focus on the characteristics and behaviors of Agrobacterium tumefaciens.

### Step 2: Identifying its Pathogenicity
Agrobacterium tumefaciens is pathogenic to several dicot plants. It utilizes a specific plasmid (the T-DNA) to insert genes into the host plant's genome, leading to tumor formation.

**Hint:** Remember that it specifically targets dicot plants and causes disease.

### Step 3: Ability to Transform Cells
The bacterium has the ability to transform normal plant cells into cancerous cells by transferring its T-DNA, which contains tumor-inducing genes.

**Hint:** Consider how Agrobacterium modifies plant cells and the implications of this transformation.

### Step 4: Delivery of Genes of Interest
In biotechnology, the T-DNA can be modified to create a cloning vector that can deliver genes of interest without causing disease. This means that while Agrobacterium can be pathogenic, it can also be engineered to be non-pathogenic for research and agricultural purposes.

**Hint:** Think about the applications of Agrobacterium in genetic engineering and how it can be modified.

### Step 5: Evaluating the Statements
Now, we need to evaluate the statements provided in the question. The statement that "Agrobacterium tumefaciens is always pathogenic to plants without any exception" is incorrect. This is because it can be modified to create non-pathogenic vectors for gene delivery.

**Hint:** Identify which statement contradicts the known capabilities of Agrobacterium tumefaciens.

### Conclusion
The statement that is not applicable to Agrobacterium tumefaciens is that it is "always pathogenic to plants without any exception." This is incorrect because it can be modified to be non-pathogenic.

**Final Answer:** The correct option is that Agrobacterium tumefaciens is "always pathogenic to plants without any exception."