`C_4` Plants can tolerate saline conditions due to

Options

A. Occurrence of organic acids
B. Absence of Photorespiraition
C. Presenc rod PEP carboxylase enzyme
D. presence of PEP Carboxylase enzyme

Answer

To answer the question "C4 plants can tolerate saline conditions due to", we can break down the solution into the following steps:

### Step-by-Step Solution:

1. **Understanding C4 Plants**:
- C4 plants are a type of plant that have a unique mechanism for photosynthesis, which allows them to efficiently fix carbon dioxide (CO2) even in conditions where CO2 concentration is low.

2. **Initial CO2 Fixation**:
- In C4 plants, the initial fixation of CO2 occurs in mesophyll cells. This is different from C3 plants, where CO2 fixation occurs in the same cells that carry out the Calvin cycle.

3. **Role of PEP Carboxylase**:
- The enzyme responsible for the initial fixation of CO2 in C4 plants is called phosphoenolpyruvate carboxylase (PEP carboxylase or PEPcase). This enzyme has a high affinity for CO2 and allows C4 plants to effectively capture CO2 even under low concentrations.

4. **Formation of Organic Acids**:
- The product of the reaction catalyzed by PEP carboxylase is oxaloacetic acid (OAA), which is an organic acid. This organic acid is crucial for the C4 pathway and helps in the efficient utilization of CO2.

5. **Tolerating Saline Conditions**:
- The presence of organic acids, such as oxaloacetic acid, plays a significant role in helping C4 plants tolerate saline conditions. These organic acids can help in osmotic regulation and maintaining cellular functions under stress conditions, including salinity.

6. **Conclusion**:
- Therefore, the correct answer to the question is that C4 plants can tolerate saline conditions due to the occurrence of organic acids.

### Final Answer:
C4 plants can tolerate saline conditions due to the occurrence of organic acids (specifically oxaloacetic acid).

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