Term 'Disarmed ' in disarmed vector represents

Options

A. Removal of T-DNA from Ti plasmid
B. Insertional inactivation of `beta-galactosidase` gene
C. Insertional inactivation of antibiotic gene
D. Both (2) & (3)

Answer

To answer the question regarding what the term "disarmed" in a disarmed vector represents, we can break down the explanation step by step:

### Step-by-Step Solution:

1. **Understanding Vectors**:
- Vectors are tools used in biotechnology to transfer genetic material (genes of interest) into a host organism. They act as vehicles for gene delivery.

2. **Agrobacterium and Tumor Inducing Plasmid (Ti Plasmid)**:
- One common vector used in plant biotechnology is derived from Agrobacterium tumefaciens, which contains a Tumor Inducing (Ti) plasmid. This plasmid has a specific region known as the T-DNA (transfer DNA) region.

3. **Role of T-DNA**:
- The T-DNA region is responsible for transferring genes that cause tumors in plants. This pathogenic property is useful for the bacterium but not for biotechnological applications where we want to insert beneficial genes instead.

4. **Disarming the Vector**:
- To create a disarmed vector, the T-DNA region, which is responsible for tumor formation, is removed from the Ti plasmid. This process is essential because it eliminates the pathogenicity of the vector.

5. **Inserting the Gene of Interest**:
- Once the T-DNA region is removed, the vector can be modified to include a gene of interest. This allows for the safe transfer of desired traits into the plant without causing tumor formation.

6. **Conclusion**:
- Therefore, the term "disarmed" in a disarmed vector refers to the removal of the T-DNA region from the Ti plasmid, rendering it non-pathogenic and suitable for the introduction of beneficial genes into plants.