Question

Deciduous plants shed their leaves during summer or in autumn. This process of shedding of leaves is called abscission. Apart from physiological changes, what anatomical mechanism is involved in the abscission of leaves.

Answer 1

Anatomical changes involved in the abscission of leaves

• In deciduous trees, an abscission zone, also called a separation zone, is formed at the base of the petiole.
• In the autumn, cells in the abscission zone secrete a waxy substance (suberin) and begin to swell, reducing the amount of nutrients and water that flow through the tubes.
• The leaves cannot produce food materials without fresh raw materials, and fall off after sometime.