There are two types of tissues to perform the function of transport system in plants; Xylem and Phloem. These are components of the Vascular Tissue System in plants. Let us study through this article about what is the difference between them.
There are two types of tissues to perform the function of transport system in plants; Xylem and Phloem . These are components of the vascular tissue system in plants. In the young parts of the stem, the xylem and phloem are arranged together as vascular bundles. Both xylem and phloem are complex tissues made up of more than one type of cells.
What is the transport system in plants?
The transport of substances absorbed or produced by any plant to all other parts of the plant is called transport system. As we know that plants need to transport water and minerals to its other parts. Similarly, it is necessary to transport the food made in the leaves of plants to other parts of the plant. Plants have branches so that they can get carbon dioxide for photosynthesis and oxygen directly from the air through diffusion .
Let us tell you right here that plants need water to make food through photosynthesis and minerals to manufacture proteins. For this reason, plants absorb water and minerals from their roots and transport it to the rest of the plant’s stem, leaves, flowers, etc.
What is the difference between Xylem and Phloem?
There are two types of tissues to perform the function of transport system in plants; Xylem and Phloem. These are components of the Vascular Tissue System in plants. Let us study through this article about what is the difference between them.
There are two types of tissues to perform the function of transport system in plants; Xylem and Phloem . These are components of the vascular tissue system in plants. In the young parts of the stem, the xylem and phloem are arranged together as vascular bundles. Both xylem and phloem are complex tissues made up of more than one type of cells.
Therefore it would not be wrong to say that xylem and phloem are two different types of vascular tissue , which are mainly involved in the transport process. These tissues form the vascular bundle and they work together as a unit. The movement of xylem is unidirectional, while that of phloem is bidirectional.
The difference between Xylem and Phloem are as follows:
1. Tissues of xylem are tubular shaped structure, in which there is absence of cross walls. This tissue resembles the shape of a star. Whereas phloem tissues are tubular shaped, elongated, having structures with presence of walls with thin sieve tubes.
2. Xylem is a vascular tissue that absorbs water and dissolved minerals from the root and transports it to the rest of the plant and Phloem is a vascular tissue that transports soluble organic compounds produced during photosynthesis from the green parts of the plant to the rest of the plant. is.
3. The xylem is mainly located at the center of the vascular bundles and the phloem is mainly localized towards the periphery of the vascular bundles.
4. The fibers of xylem are short and the fibers of phloem are large.
5. Xylem is present in roots, stem and leaves and phloem is present in stem and leaves, which later transfer and develop into roots, fruits and seeds.
6. The movement of xylem is in one direction i.e. unidirectional upwards while that of phloem is bidirectional (up and down).
7. Xylem includes Tracheids, Vessel Elements, Xylem Parenchyma, and Xylem Fibers. Whereas phloem includes: Companion Cells, Sieve Tubes, Bast Fibres, Phloem Fibers, and Phloem Parenchyma.
8. Cells of xylem tissue are dead cells except parenchyma cells and cells of phloem tissue are living cells except bast fibers.
9. Cell wall of cells in xylem is thick and cell wall of cells of phloem is thin.
10. Lignified cell wall is present in xylem and cell wall is not lignified in phloem.
11. Vascular bundles contain more xylem tissue than phloem tissue i.e. vascular tissue has comparatively less amount of phloem tissue.
12. Water and minerals are carried from the roots of the plant to its leaves through two types of elements of xylem tissue i.e. Xylem Vessels and Tracheid and the living cells of the phloem are called ‘Sieve Tubes’. ) are called. Sieve plates are found on the end wall of cells in phloem, in which small pores are made.
13. The xylem transports soluble mineral nutrients and water molecules from the roots to other parts of the plant and the phloem transports food and other nutrients including sugar and amino acids from the leaves to the storage organs and growing parts of the plant.
14. Xylem provides mechanical strength to the plant and helps the stem to stay strong while circulating sugars synthesized by the photosynthetic regions of plants for storage of organs such as roots, bulbs and tubes. is.
15. Xylem replenishes the total amount of water molecules lost through transpiration and photosynthesis and is responsible for the transport of proteins and mRNAs throughout the plant.
xylem
1). Xylem transports water and dissolved salts from the root to the leaves and other parts.
2). Materials are transported in the xylem by vessels and ducts, which is dead tissue.
3). Due to the transpiration bridge, it is possible for water and dissolved salts to rise upwards. This is due to the pull caused by evaporation of water molecules from the leaf cells.
4). Transport of water takes place under simple physical motion. Energy is not spent. Hence ATP is not required.
Phloem
1). Phloem transports food substances in dissolved form from leaves to other parts of the plant.
2). The transport of materials in the phloem takes place through sieve tubules with the help of companion cells, which are biological cells.
3). In transfer, matter is carried in the phloem tissue using ATP energy. This increases the osmotic pressure, which sends substances from the phloem to the tissues, which have less pressure.
4). Transfer to the phloem is an active process and requires energy. This energy is obtained from ATP.
Xylem: This tissue is found in the root, stem and leaves of plants. It is also called conducting tissue. It is made up of four different types of elements. These are
(a) Tracheids, (b) Vessels (c) Xylem fibers and (d) Xylem parenchyma.
(a) Tracheids: Their cells are elongated, without protoplasm, pointed at both ends and are dead. Their cell wall is thick and voluminous. Vessels are found in both primary and secondary xylem of vascular plants. They provide mechanical support to the plants and transport water from the root to the leaves through the stem.
(b) Vessels: Their cells are dead and long like tubes. Sometimes the corpuscles thicken in different ways to form annular, spiral, stair-like, pitted, reticulate vessels. These vessels are found in the primary and secondary xylem of angiosperm plants. They transport water and mineral salts from the roots of plants to the leaves.
(c) Xylem fibres: These are long, conical shaped dead cells with thick walls. They are often found in woody dicot plants. They mainly provide mechanical support to the plants.
(d) Xylem parenchyma: Their cells are usually parenchymatous and live. It serves as a food store. It helps in vegetative convection of water towards the shore.
(ii) Phloem: Like xylem, phloem is also found in the root, stem and leaves of plants. It transports the food prepared by the leaves to the different parts of the plant. It is a storage tissue that provides mechanical storage to plants. Phloem is made up of the following four elements- (a) sieve tubes, (b) companion cells (c) phloem fibers and (d) phloem parenchyma.
(a) Sieve tubes: These are cells with long, cylindrical and perforated walls. They are layered on each other. The division wall of two cells is porous, which is called sieve plate. The nucleus is absent in the adult stage of the sieve tube. The cytoplasm of a sieve tube is connected to the top and bottom sieve tubes through the pores of the sieve plate. Sieve tubes are found in the phloem of vascular plants. The food prepared by this tube travels from the leaves to the storage organ and from the storage organ to the growth zone of the plant.
(b) Companion Cells: These are located on the side of the sieve tubules. Each co-cell is elongated and living having nucleus and protoplasm. It is found only in the phloem of angiosperms. It helps in the transportation of food through the sieve tubes.
(c) Phloem fibres: These are long, rigid and made up of sclerenchymatous cells. It provides mechanical support to the phloem tissue.
(a) Phloemparenchyma: These are living, elongated and nucleated cells located near co-cells. They help in the transportation of food items.
What are the main functions of xylem and phloem?
The tracheids and vessels act as the flow of water and minerals from the roots of the plant to the leaves. These help in the formation of soft and hard wood respectively. Xylem Parenchyma stores food. Xylem fibers provide mechanical support.
