Name the plant hormone that causes bolting in cabbage plants.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the name of the plant hormone that causes bolting in cabbage plants. Bolting refers to the rapid elongation of the stem, leading to flowering.

2. **Identifying the Hormone**: The hormone responsible for bolting in cabbage is **gibberellin**. Gibberellins are a group of plant hormones that promote growth and influence various developmental processes.

3. **Explaining the Role of Gibberellin**: Gibberellins play a crucial role in:
- **Stem Elongation**: They promote the elongation of stems, which is essential during the bolting process.
- **Seed Germination**: Gibberellins help in the breakdown of starches into sugars during seed germination, facilitating growth.
- **Changing Rosette Nature**: Cabbage plants exhibit a rosette growth form, which is a compact arrangement of leaves. The application of gibberellin changes this rosette form into an elongated floral stalk, leading to bolting.

4. **Conclusion**: Therefore, the plant hormone that causes bolting in cabbage plants is **gibberellin**.

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