the aleurone synthesizes and secretes digestive enzymes that hydrolyse nutrients stored in the endosperm in the presence of

Options

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

Answer

To solve the question regarding the role of the aleurone layer in synthesizing and secreting digestive enzymes that hydrolyze nutrients stored in the endosperm, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Aleurone Layer**:
- The aleurone layer is the outermost layer of the endosperm in seeds. It plays a crucial role in the germination process.

**Hint**: Remember that the aleurone layer is part of the seed structure and is involved in nutrient mobilization during germination.

2. **Function of the Aleurone Layer**:
- The primary function of the aleurone layer is to synthesize and secrete digestive enzymes. These enzymes are responsible for hydrolyzing stored nutrients in the endosperm, which provides energy and building blocks for the developing embryo.

**Hint**: Think about how seeds need to access stored nutrients for growth when they begin to germinate.

3. **Role of Plant Hormones**:
- The secretion of these digestive enzymes from the aleurone layer is regulated by plant hormones. In this case, gibberellic acid (GA) is the key hormone that stimulates the aleurone layer to produce these enzymes.

**Hint**: Consider which plant hormones are known to promote growth and development, especially during seed germination.

4. **Identifying the Correct Hormone**:
- Among the options provided (auxin, gibberellin, cytokinin, and ethylene), gibberellin is the hormone that specifically aids in the synthesis and secretion of enzymes like alpha-amylase, which converts stored starches into sugars.

**Hint**: Recall the specific functions of each hormone: auxin is for growth direction, cytokinin for cell division, ethylene for ripening, and gibberellin for germination.

5. **Conclusion**:
- Therefore, the correct answer to the question is gibberellin, as it is essential for the aleurone layer to synthesize and secrete the digestive enzymes necessary for hydrolyzing nutrients in the endosperm.

**Hint**: Summarize by focusing on the relationship between gibberellin and the aleurone layer's function during seed germination.

### Final Answer:
The aleurone synthesizes and secretes digestive enzymes that hydrolyze nutrients stored in the endosperm in the presence of gibberellin.