Leaf Epidermis
The epidermis is a single-layered group of cells that covers the leaves, flowers, roots and stems of a plant. It acts as a boundary between the plant and its outer environment. The epidermis has many functions; it protects against water loss, controls the gas exchange, lets out metabolic compounds, and absorbs water and mineral nutrients (especially in roots). The epidermis is the outermost cell layer of the primary plant body. In some older works, the cells of the leaf epidermis have been regarded as parenchyma cells, but the modernized preference has classified the epidermis as dermal tissue, whereas parenchyma is classified as ground tissue. The epidermis is the main component of the dermal tissue system of leaves, stems, roots, flowers, fruits and seeds; it is usually transparent.
The cells of the epidermis are structurally and functionally variable. Most plants have an epidermis that is a single cell layer thick. Some plants have an epidermis with multiple cell layers. Epidermal cells are tightly linked to each other and provide
mechanical strength and protection to the plant. The walls of the epidermal cells of the above ground parts of plants contain something called cutin, and are covered with a cuticle. The cuticle reduces water loss to the atmosphere, it is sometimes covered with wax in smooth sheets, granules, plates, tubes or filaments. The wax layers give some plants a whitish or bluish surface color.
Surface wax acts as a moisturizer and protects the plant from intense sunlight and wind. The under-side of many leaves have a thinner cuticle than the top side, and leaves of plants from dry climates often have thickened cuticles to conserve water by reducing transpiration. The epidermal tissue includes many different cells; epidermal cells, guard cells and epidermal hairs. The epidermal cells are the largest and least specialized.
The cells of the epidermis are structurally and functionally variable. Most plants have an epidermis that is a single cell layer thick. Some plants have an epidermis with multiple cell layers. Epidermal cells are tightly linked to each other and provide
mechanical strength and protection to the plant. The walls of the epidermal cells of the above ground parts of plants contain something called cutin, and are covered with a cuticle. The cuticle reduces water loss to the atmosphere, it is sometimes covered with wax in smooth sheets, granules, plates, tubes or filaments. The wax layers give some plants a whitish or bluish surface color.
Surface wax acts as a moisturizer and protects the plant from intense sunlight and wind. The under-side of many leaves have a thinner cuticle than the top side, and leaves of plants from dry climates often have thickened cuticles to conserve water by reducing transpiration. The epidermal tissue includes many different cells; epidermal cells, guard cells and epidermal hairs. The epidermal cells are the largest and least specialized.
Tricomes or hairs grow out from the epidermis in many species. In root epidermis, epidermal hairs also called root hairs are common and are specialized for absorbption of water and mineral nutrients.
The plant epidermis consists of three main cell types: pavement cells, guard cells and their useful cells that surround the stomata and trichomes, otherwise known as leaf hairs. The epidermis of petals also form a variety of trichomes called conical cells. These cells all develop from the pavement cells, which make up the majority of the plants surface cells. In addition, original seperation of the epidermal cells is controlled by two major factors: genetics and environmental conditions.
The plant epidermis consists of three main cell types: pavement cells, guard cells and their useful cells that surround the stomata and trichomes, otherwise known as leaf hairs. The epidermis of petals also form a variety of trichomes called conical cells. These cells all develop from the pavement cells, which make up the majority of the plants surface cells. In addition, original seperation of the epidermal cells is controlled by two major factors: genetics and environmental conditions.