The function of leghaemoglobin in the root nodules of legumes is

Options

A. Inhibition of nitrogenase activity
B. Oxygen removal
C. Nodule differentiation
D. Expression of nif gene

Answer

**Step-by-Step Text Solution:**

1. **Understanding Leghemoglobin**: Leghemoglobin is a red-colored pigment found in the root nodules of legumes. It is similar to hemoglobin found in blood, but it is specifically adapted to function in plant root nodules.

2. **Location of Leghemoglobin**: This pigment is located in the cytoplasm of the root nodules, which are specialized structures formed by the symbiotic relationship between legumes and nitrogen-fixing bacteria (like Rhizobium).

3. **Function of Leghemoglobin**: The primary function of leghemoglobin is to bind and transport oxygen within the root nodules. This is crucial because nitrogen-fixing bacteria require a low-oxygen environment to effectively convert atmospheric nitrogen (N₂) into ammonia (NH₃).

4. **Oxygen Scavenging**: Leghemoglobin acts as an oxygen scavenger. It removes free oxygen from the root nodule environment, thereby creating an anaerobic (low oxygen) condition that is favorable for the nitrogenase enzyme, which is responsible for nitrogen fixation.

5. **Impact on Nitrogenase Activity**: By maintaining low oxygen levels, leghemoglobin enhances the activity of nitrogenase. Since nitrogenase is sensitive to oxygen, its activity would be inhibited in the presence of high oxygen levels. Therefore, leghemoglobin plays a critical role in facilitating nitrogen fixation.

6. **Conclusion**: Based on the functions described, the correct answer to the question regarding the function of leghemoglobin in the root nodules of legumes is "oxygen removal."

**Final Answer**: The function of leghemoglobin in the root nodules of legumes is oxygen removal.

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