Binding of symbiotic nitrogen fixing bacteria to the surface of root hair cell is promoted by the following substance

Options

A. Vinblastin
B. Curcumin
C. Codeine
D. Concanavalin A

Answer

To solve the question regarding which substance promotes the binding of symbiotic nitrogen-fixing bacteria to the surface of root hair cells, we can analyze the provided options step by step.

### Step 1: Understand the role of symbiotic nitrogen-fixing bacteria
Symbiotic nitrogen-fixing bacteria, such as Rhizobium, form a mutualistic relationship with leguminous plants. They help the plants by converting atmospheric nitrogen into a form that the plants can use, while the plants provide carbohydrates and a suitable environment for the bacteria.

**Hint:** Look for substances that facilitate the interaction between bacteria and plant cells.

### Step 2: Analyze the options
1. **Windblastin**: This is a chemotherapy drug used in cancer treatment. It does not have any known role in promoting the binding of bacteria to plant cells.
- **Hint:** Consider whether the substance is related to plant biology or medicine.

2. **Curcumin**: A bright yellow chemical derived from turmeric, known for its anti-inflammatory properties and used in various herbal supplements. However, it does not play a role in the binding of nitrogen-fixing bacteria.
- **Hint:** Think about whether the substance is involved in plant-microbe interactions.

3. **Codine**: A prodrug of morphine used for pain relief. It is not related to plant biology or the binding of bacteria.
- **Hint:** Evaluate if the substance has any relevance to plant-microbe symbiosis.

4. **Concavalin A**: This is a lectin, a type of protein that binds specifically to carbohydrates. Lectins are known to facilitate the binding of bacteria to plant cells, including the root hair cells, thus promoting the symbiotic relationship.
- **Hint:** Identify if the substance has a specific function in carbohydrate binding.

### Step 3: Conclusion
After analyzing all the options, it is clear that the correct answer is **Concavalin A**. This lectin promotes the binding of symbiotic nitrogen-fixing bacteria to the surface of root hair cells, facilitating the symbiotic relationship.

### Final Answer
The binding of symbiotic nitrogen-fixing bacteria to the surface of root hair cells is promoted by **Concavalin A**.