Adventitious root

Adventitious roots are roots that form from non-root tissues such as stems, old roots, or leaves. They are a type of plant root system that differs from the primary root system, which originates from the radicle of a seedling. Adventitious roots are often formed as a response to stress conditions, such as flooding, nutrient deficiency, or wounding. They play a crucial role in the survival and growth of many plant species.

Formation

Adventitious roots form from meristematic cells, which are undifferentiated cells capable of cell division and formation of new tissues. These cells can be found in various parts of the plant, including the cambium, pericycle, and cortex. The formation of adventitious roots involves a complex process that is regulated by various plant hormones, including auxin, ethylene, and abscisic acid.

Functions

Adventitious roots perform several functions, depending on the species and the environmental conditions. They can provide additional support to the plant, especially in species that grow in water or on other plants. They can also help in the absorption of water and nutrients, especially in species that grow in nutrient-poor environments. In some species, adventitious roots can store food and water, providing a reserve for times of scarcity.

Types

There are several types of adventitious roots, including:

• Prop roots: These roots grow from the stem and reach the ground, providing additional support to the plant. They are common in species such as corn and banyan trees.
• Aerial roots: These roots hang in the air and absorb moisture from the atmosphere. They are common in species such as orchids and mosses.
• Climbing roots: These roots help the plant to climb on other plants or structures. They are common in species such as ivy and vines.
• Storage roots: These roots store food and water. They are common in species such as sweet potatoes and carrots.

See also

• Root
• Plant physiology
• Plant hormone
• Meristem