Deciduous plants shed their leaves during hot 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.
Ans. Shedding of leaves in plants is known as abscission of leaves. Apart from physiological changes, anatomical changes are also involved in the shedding of leaves.
Some anatomical changes are –
1. Formation of an abscission zone, also known as a separation zone, at the base of the petiole in deciduous trees. This zone is made up a weak top layer and a bottom layer. In the autumn season, the bottom layer expands, breaking the cells of the top layer, which allows the leaf to shed.
2. Excess loss of chlorophyll can also attribute to the falling of the leaves.
3. Hormonal change can also occur in deciduous trees due to excess secretion of abscisic acid, which stimulates the process of abscission.
The abscission zone is also called the separation zone. It is formed at the base of the petiole. It is composed of a top layer and a bottom layer. The cells in the top layer have weak cell walls. The bottom layer expands in winter and breaks the cell walls of the top layer. This results in shedding of leaves.