The dermal tissue functions to protect the plant.
The dermal tissue system is the plant's outer protective covering, much like skin in animals. It's crucial for shielding the plant from various environmental stressors. Let's break down its key components and functions:
- Epidermis: This is the outermost layer of the dermal tissue system in young plants.
- It provides a protective barrier against physical damage, pathogens, and water loss.
- Epidermal cells often secrete a waxy coating called the cuticle.
- Cuticle: This waxy layer is secreted by epidermal cells.
- It's primarily composed of cutin, a fatty substance.
- The cuticle's main function is to prevent excessive water loss from the plant's surface. This is particularly important in terrestrial plants.
- Periderm: In woody plants, the epidermis is replaced by the periderm as the plant matures.
- The periderm is thicker and more robust than the epidermis.
- It provides even greater protection against damage, infection, and dehydration.
- It forms the outer bark of trees.
- Specialized Cells: The dermal tissue also contains specialized cells with specific functions:
- Trichomes: Hair-like outgrowths that can protect against herbivores, reduce water loss, or secrete substances.
- Guard cells: These cells surround stomata, which are pores in the epidermis that allow for gas exchange. Guard cells regulate the opening and closing of stomata.
In summary, the dermal tissue acts as the plant's first line of defense, protecting it from the environment and helping it to regulate water loss and gas exchange.
