Abscission

Definition

Abscission is the process by which plants shed leaves, flowers, or fruits. It is a crucial mechanism for plant survival and adaptation, often triggered by environmental cues or hormonal changes.

5 Must Know Facts For Your Next Test

1. Abscission involves the formation of an abscission zone at the base of the plant organ to be shed.
2. Ethylene is a key hormone that promotes abscission, while auxin can inhibit it.
3. The process helps plants conserve resources during unfavorable conditions like drought or cold weather.
4. Cellular changes in the abscission zone include cell wall degradation and increased enzyme activity.
5. Abscission also plays a role in the dispersal of seeds and removal of damaged or diseased organs.

Review Questions

• What role does ethylene play in the process of abscission?
• How does the formation of an abscission zone contribute to leaf shedding?
• Why might a plant benefit from shedding its leaves during drought conditions?

Related terms

Ethylene:

A gaseous plant hormone involved in regulating growth, development, and responses to stress.

Auxin: A class of plant hormones that regulate various aspects of growth and development, including cell elongation and division.

Senescence: The process of aging in plants where cells undergo physiological and biochemical changes leading to death.