Identify the role of lectins in formation of root nodules in legumes.

Options

A. Formation of shepherd crook
B. Recognition of compatible Rhizobium by host
C. Formation of peribacterial membrane
D. Formation of inection thrread

Answer

**Step-by-Step Solution:**

1. **Understanding Lectins**: Lectins are carbohydrate-binding proteins that play a crucial role in various biological processes, including plant defense and symbiotic relationships.

2. **Role in Symbiotic Associations**: In legumes, lectins are involved in the symbiotic relationship between the plant and nitrogen-fixing bacteria, specifically rhizobia. This relationship is vital for the plant's ability to utilize atmospheric nitrogen.

3. **Recognition of Compatible Rhizobium**: One of the primary roles of lectins in the formation of root nodules is the recognition of compatible rhizobium by the host plant. When a legume plant's roots encounter rhizobia, the lectins bind to specific carbohydrates on the surface of the rhizobia, facilitating the recognition process.

4. **Initiation of Nodule Formation**: Once the compatible rhizobium is recognized, the plant initiates a series of physiological responses that lead to the formation of root nodules. This includes the formation of an infection thread, which allows the bacteria to enter the plant cells.

5. **Conclusion**: Therefore, the role of lectins in the formation of root nodules in legumes primarily revolves around their function in recognizing compatible rhizobium, which is essential for establishing the symbiotic relationship necessary for nitrogen fixation.

**Final Answer**: The correct answer is that lectins help in the recognition of compatible rhizobium by the host.

---