A phytohormone involved in the de novo synthesis of `alpha`-amylase in germinating seeds is
(a) Auxin
(b) Gibberellin
(c) Ethylene
(d) Cytokinin

Options

A. Auxin
B. Gibberellin
C. Ethylene
D. Cytokinin

Answer

To solve the question regarding which phytohormone is involved in the de novo synthesis of alpha-amylase in germinating seeds, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for a phytohormone that promotes the synthesis of alpha-amylase during seed germination.

2. **Identify the Options**: The options given are:
- (a) Auxin
- (b) Gibberellin
- (c) Ethylene
- (d) Cytokinin

3. **Recall the Functions of Each Hormone**:
- **Auxin**: Primarily involved in cell elongation and differentiation.
- **Gibberellin**: Known to promote seed germination and is crucial for the synthesis of enzymes like alpha-amylase.
- **Ethylene**: Involved in fruit ripening and senescence.
- **Cytokinin**: Promotes cell division and growth, but not specifically linked to alpha-amylase synthesis.

4. **Focus on Gibberellin**: Gibberellin is well-documented for its role in breaking seed dormancy and initiating germination. It stimulates the production of enzymes, including alpha-amylase, which helps in breaking down stored starches into sugars that the embryo can use for growth.

5. **Conclude the Answer**: Based on the functions of the hormones, the correct answer is (b) Gibberellin, as it is the hormone that facilitates the de novo synthesis of alpha-amylase in germinating seeds.

### Final Answer:
(b) Gibberellin

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