Which one demonstrates process associated with abscission of a leaf

Options

A. In the leaf concentration of both auxin and ABA decreases
B. In the leaf concentration of both auxin and ABA increases
C. Reduction in ABA concentration and increase of auxin concentration in the leaf
D. Reduction in concentration of auxin and increase of concentration of ABA in the leaf.

Answer

To answer the question "Which one demonstrates the process associated with abscission of a leaf?", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Abscission**:
- Abscission refers to the process by which leaves, fruits, or flowers detach from a plant. It is a natural part of a plant's life cycle.

2. **Role of Phytohormones**:
- Plant growth regulators, also known as phytohormones, play a crucial role in regulating various processes in plants, including abscission.

3. **Identifying Key Hormones**:
- Two important hormones involved in the process of leaf abscission are Auxin and Abscisic Acid (ABA).
- **Auxin**: This hormone generally inhibits leaf abscission. Higher levels of auxin help keep the leaves attached to the plant.
- **Abscisic Acid (ABA)**: This hormone promotes leaf abscission, especially under stress conditions. It is often referred to as a stress hormone.

4. **Mechanism of Abscission**:
- During unfavorable environmental conditions, the concentration of ABA increases while the concentration of auxin decreases.
- This shift in hormone levels triggers the abscission process, leading to the detachment of leaves from the plant.

5. **Conclusion**:
- The correct answer to the question is that the process associated with leaf abscission involves a **reduction in auxin concentration and an increase in ABA concentration**.

### Final Answer:
- The correct option that demonstrates the process associated with abscission of a leaf is the one indicating a **reduction in auxin concentration and an increase in ABA concentration**.

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