The structural features of the columnar tissue of the leaf determine the fulfillment of its most important functions. Thanks to this, the vital activity of the entire plant organism is carried out. In our article, we will consider the distinguishing features of the anatomy and physiology of columnar tissue.
Features of the internal structure of the sheet
In a plant, columnar tissue is located in the leaf. How does this organ work? Outside it is covered with skin. This variety of integumentary tissue consists of tightly fitting living cells, among which are the stomata. Due to these structures, molecules of gaseous substances penetrate: oxygen - into the plant, and carbon dioxide and water vapor - in the opposite direction.
Under the skin are the cells of the main photosynthetic tissue. They are large, loosely located, so they form the basis of the sheet. The conductive and supporting function is performed by the veins - a combination of elements of the conductive and mechanical tissue. Together they form vascular fibrous bundles.
Main sheet fabric
The main tissue consists of two types of cells: columnar and spongy. The latter are oval in shape, and intercellular spaces are located between them. These structures occupy up to a quarter of the sheet. Elements of the main tissue with intercellular spaces form the basis of the sheet, store various substances, participate in gas exchange. The structural features of the columnar tissue make it the main photosynthetic structure of the leaf.
Column Fabric: Location
The figure of the columnar cell tissue of the leaf illustrates the features of its location. It is located directly under the skin on the upper side of the leaves. Cells of this tissue, really resembling columns, can be placed in one or more rows. This arrangement is explained by its main function - the implementation of photosynthesis. It is optimal for the absorption of oxygen and sunlight.
Features of the structure of columnar tissue
Columnar is a type of plant tissue. Its cells are cylindrical in shape, arranged vertically and fit snugly against each other. The number of layers of columnar tissue directly depends on the intensity of solar radiation. So, in the leaves of plants that grow in the light, there may be several. And in shade-tolerant species, this tissue is poorly developed.
The columnar cell pattern of leaf tissue demonstrates its basic structure. This is a thin shell, nucleus, mitochondria, Golgi complex, EPS. The central position and the main volume of the cell is vacuole. This cavity, filled with cellular juice, is a kind of reservoir for the supply of water and substances dissolved in it. Due to the presence of chloroplasts, the cells of the columnar tissue are green, giving it and the entire sheet.
Different parts of plants can be photosynthesizing. For example, in cacti, the leaves of which are reduced to thorns, the fleshy stem performs this function. Many unicellular organisms are also capable of photosynthesis: chlamydomonas, green euglena, cyanobacteria.
Column cloth: functions performed
Columnar cells contain the largest number of chloroplasts compared to other elements of the underlying tissue. Therefore, their main function is the implementation of photosynthesis. It is difficult to overestimate its value, therefore, its scale is often called planetary.
This photochemical process occurs on the inner membrane of chloroplasts, subject to the presence of sunlight, carbon dioxide and water. The products of this reaction are glucose monosaccharide. His plant uses as a source of energy necessary for its growth and development. When combined in chains, glucose forms a complex carbohydrate starch. Its granules are deposited in reserve in the cytoplasm in the form of inclusions.
The second product of the photosynthesis reaction is oxygen. This gas is a necessary condition for aerobic respiration, which is the main sign of all life on the planet. The essence of this process is the oxidation of organic substances with the release of energy from their chemical bonds. The structural features of the columnar tissue provide the orientation of chloroplasts, which allows them to capture sunlight as efficiently as possible.
So, columnar tissue is a kind of core. Its cells have a cylindrical elongated shape and are vertically located under the upper skin of the sheet. The functions of columnar tissue are determined by structural features: its cells contain green chloroplast plastids and provide photosynthesis. This process of planetary significance provides the main conditions of life. As a result, plants are provided with organic substances, due to which they feed, and all other organisms are provided with oxygen necessary for respiration.