What is Periderm?
Periderm is a protective tissue that develops in plants as a response to external factors such as mechanical damage, pathogens, and environmental stress. It is a secondary tissue that replaces the epidermis in older parts of the plant, providing a protective barrier against water loss and pathogens. Periderm is composed of several layers of cells, including cork cells, phelloderm, and phellogen (cork cambium).
What are the functions of Periderm?
The primary function of periderm is to protect the plant from external factors such as physical damage, pathogens, and water loss. It also helps in the exchange of gases and nutrients between the plant and its environment. Periderm acts as a barrier that prevents the entry of pathogens and reduces water loss through transpiration. Additionally, periderm provides structural support to the plant and helps in wound healing.
How is Periderm formed?
Periderm is formed by the activity of the cork cambium (phellogen), which is a lateral meristem located in the outer layers of the stem and roots. The cork cambium produces new cells that differentiate into cork cells (phellem) on the outside and phelloderm cells on the inside. The cork cells are dead at maturity and are impregnated with suberin, a waxy substance that makes them impermeable to water and gases. The phelloderm cells are living and provide metabolic support to the periderm.
What are the different layers of Periderm?
Periderm consists of three main layers of cells: cork cells (phellem), phelloderm, and cork cambium (phellogen). The cork cells are the outermost layer of the periderm and are dead at maturity. They are impregnated with suberin, which makes them impermeable to water and gases. The phelloderm is a layer of living cells located on the inner side of the cork cells and provides metabolic support to the periderm. The cork cambium is a lateral meristem that produces new cells to replace the epidermis in older parts of the plant.
What is the significance of Periderm in plants?
Periderm plays a crucial role in the survival and growth of plants by providing protection against external factors such as physical damage, pathogens, and water loss. It also helps in the exchange of gases and nutrients between the plant and its environment. Periderm is essential for the structural integrity of the plant and contributes to wound healing and tissue repair. Without periderm, plants would be more susceptible to environmental stress and would have a reduced ability to adapt to changing conditions.
How does Periderm contribute to plant growth and development?
Periderm contributes to plant growth and development by providing protection and support to the plant’s vascular system. It helps in the formation of a protective barrier that prevents the entry of pathogens and reduces water loss through transpiration. Periderm also plays a role in wound healing and tissue repair, allowing the plant to recover from injuries and continue to grow. Overall, periderm is essential for the long-term survival and success of plants in a variety of environments.