Major precursor of ethylene production in plants is

Options

A. lysine
B. methionine
C. alanine
D. valine

Answer

### Step-by-Step Solution:

1. **Understanding Ethylene**: Ethylene is recognized as a plant hormone or phytohormone that plays a crucial role in various plant processes. It is involved in the regulation of growth and development in plants.

2. **Functions of Ethylene**: Ethylene has several important functions, including:
- Stimulating the ripening of fruits.
- Promoting the opening of flowers.
- Inducing the abscission (shedding) of leaves.

3. **Identifying Precursors**: To understand the production of ethylene, we need to identify its precursor. A precursor is a substance from which another is formed.

4. **Options Analysis**: The options provided are:
- A. Lysine
- B. Methionine
- C. Alanine
- D. Valine

5. **Research on Precursors**: Among the amino acids listed, methionine is known to be the major precursor for ethylene production in plants. Methionine undergoes a series of biochemical reactions to eventually produce ethylene.

6. **Conclusion**: Therefore, the correct answer to the question "Major precursor of ethylene production in plants is" is **Option B: Methionine**.