Which of the following trace element is essential for auxin synthesis in plants

Options

A. Molybdenum
B. Chlorine
C. Zinc
D. Boron

Explanation

To determine which trace element is essential for auxin synthesis in plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Auxin**: Auxin is a plant hormone that plays a crucial role in growth and development. The most common form of auxin is Indole Acetic Acid (IAA).

2. **Identify Trace Elements**: The question provides several trace elements as options. We need to evaluate their roles in plant physiology, particularly in relation to auxin synthesis.

3. **Evaluate Each Option**:
- **Molybdenum**: This trace element is primarily involved in nitrogen fixation and does not play a direct role in auxin synthesis.
- **Chlorine**: Chlorine is important for processes like osmosis and stomatal function but is not directly involved in auxin synthesis.
- **Zinc**: Zinc is known to influence the synthesis of plant hormones, including auxins. It plays a critical role in various enzymatic reactions and protein synthesis related to hormone production.
- **Boron**: Boron is essential for cell wall formation and stability but does not directly influence auxin synthesis.

4. **Conclusion**: Among the options provided, zinc is the trace element that is essential for auxin synthesis in plants.

### Final Answer:
**Zinc** is the trace element essential for auxin synthesis in plants.

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