Structure that protects the plant body against the invasion of parasites

Plant Epidermis
The epidermis is the outermost layer of cells in the plant body that acts as a protective covering against the invasion of parasites. It consists of a single layer of tightly packed cells that cover the entire surface of the plant, including leaves, stems, and roots.

Structure and Function of Epidermis
The epidermal cells are covered by a waxy layer called the cuticle, which helps in reducing water loss and protects the plant from desiccation. The cuticle acts as a physical barrier and prevents the entry of parasites, pathogens, and harmful substances into the plant body.

Stomata
Stomata are small openings found on the surface of leaves and stems. They are surrounded by two specialized epidermal cells called guard cells. Stomata allow the exchange of gases, such as carbon dioxide and oxygen, between the plant and its surroundings. However, they can also act as entry points for parasites.

Structure and Function of Stomata
Stomata can regulate the opening and closing of the pore by changing the shape of the guard cells. This helps in controlling the exchange of gases and the movement of water vapor. When closed, stomata prevent the entry of parasites, pathogens, and dust particles, reducing the chances of infection or infestation.

Trichomes
Trichomes are hair-like structures that are present on the epidermis of plants. They can be found on leaves, stems, and flowers. Trichomes can have various shapes, sizes, and functions, including protection against parasites.

Structure and Function of Trichomes
Trichomes can act as a defense mechanism by physically impeding the movement of parasites and insects. Some trichomes are glandular and produce sticky substances or toxic compounds that deter herbivores and parasites. They can also reduce water loss by creating a layer of still air around the leaf surface, which decreases transpiration.

Conclusion
The plant epidermis, along with its specialized structures such as stomata and trichomes, provides a protective barrier against the invasion of parasites. The cuticle, stomata, and trichomes act as physical barriers, regulate gas exchange, and produce deterrent substances, reducing the risk of infection and infestation. These adaptations contribute to the overall defense mechanism of plants, allowing them to survive and thrive in various environments.