Study the following statements regarding Bt toxins produced by bacterium Bacillus thuringiensis and select the correct one

Options

A. Perforation of gut wall in insects
B. killing of bacterial cells
C. its secretion in active form
D. prevention of formation of bolls in cotton

Answer

To analyze the statements regarding Bt toxins produced by the bacterium Bacillus thuringiensis (Bt), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Bacillus thuringiensis (Bt)**:
- Bacillus thuringiensis is a bacterium that produces insecticidal proteins known as Bt toxins. These toxins are effective against various insect pests.

2. **Mechanism of Action**:
- During its life cycle, particularly during sporulation, Bt forms crystalline bodies that contain these insecticidal proteins in an inactive form known as protoxins.

3. **Ingestion by Insects**:
- When insects consume plants that have been treated with Bt or the bacteria itself, they also ingest these protoxins.

4. **Activation of Protoxins**:
- In the alkaline environment of the insect's gut, these protoxins are cleaved by proteases into active forms of the toxin.

5. **Effect of Active Toxins**:
- The active toxins create pores in the gut lining of the insect, leading to swelling and lysis (breaking down) of the gut cells.

6. **Consequences for the Insect**:
- The damage to the gut walls prevents the insect from feeding, ultimately causing it to starve to death.

7. **Conclusion**:
- Based on the above understanding, one of the correct statements regarding Bt toxins is that they cause perforation of the gut walls in insects, leading to their death.

### Final Answer:
- The correct statement regarding Bt toxins produced by Bacillus thuringiensis is that they cause perforation of the gut walls in insects.