Differences between Xylem and Phloem (Full Details)

Both the xylem and the phloem are intricate permanent tissues. However, they have diverse functions in plants. The xylem aids in the movement of water from the roots to the rest of the plant. The phloem, on the other hand, facilitates in the movement of photosynthesized food material from the source to the other.

The flow of xylem is unidirectional and only occurs from the roots to the upper plant body. The phloem, on the other hand, transports food material in both directions, from up to down.

In this section, we will discover the distinctions between xylem and phloem.

Xylem and Phloem

What Is Xylem?

The term xylem derives from the ancient Greek term xylon, which meaning “wood.” Carl Nageli coined this phrase in the year 1858. Xylem is a complex, permanent vascular network that transports sap and water. They get hard as a plant grows and eventually change into wood.

Only from the root region to the top plant organs do the xylem tissues transport water, salt, and minerals. As a result, this flow is entirely one-way. These tissues must transport the materials against gravity.

Importance of Xylem

The primary purpose of the xylem is to transport and deliver water from the roots to the rest of the plant. Water can be a limiting factor in plant growth, development, and output. It also influences the vegetation of a certain location. As a result, we may deduce the significance of water transport in the plant.

Xylem Functioning

Water, minerals, salts, and other inorganic substances are transported from the roots to the various plant sections by xylem tissues. This fluid running through the xylem is known as xylem sap. Capillary action is the system that allows this transfer in the upward direction, i.e. against gravitational force. The surface tension of the liquid is used in this capillary action mechanism.

Note: This xylem sap movement does not require any external energy, making it a sort of passive transport.

Types of Xylem

All xylem kinds serve the same purpose. However, we can categorize xylem growth into two types: primary and secondary.

Primary Xylem

They are formed during the plant’s initial growth. It is mainly found in areas of rapid growth, such as the tips of roots and shoots, floral buds, and so on. Their function remains unchanged: they convey water and sap. They also lengthen the roots and branches to make the plant longer.

Secondary Xylem

They develop during a plant’s secondary growth. These xylems enlarge the tree trunks by increasing the girth of the plant body. These secondary meristems are responsible for the plant’s black rings, which identify its age. They are extremely common in two plant groups: angiosperms and gymnosperms.

Example: Conifers, mango tree, pines etc.]

What Is Phloem?

The term phloem, like xylem, comes from the ancient Greek language. It is derived from the Greek word pholoios, which means “bark.” Carl Nageli pioneered it in 1858.

Phloem is the complex permanent tissue of plants that is responsible for the transport of food material. During photosynthesis, green plant components synthesize organic nourishment from naturally accessible inorganic substances. Phloem acts as a conductor, transporting this food supply to the various plant components for consistent growth.

Note: The process of food transportation in plants via Phloem is called translocation.

Importance of Phloem

The Phloem is the only tissue capable of transporting food across great distances. The food produced in the source organs is efficiently transported to the sink organs for long-term growth. Different hydrostatic forces between the source and sink organs are used in the translocation mechanism. Turgor pressure primarily transports food assimilates.

Working of Phloem

The translocation mechanism is an active mode of transport that necessitates the use of ATP. The turgor pressure is used by the Phloem for transportation. The higher the solute content within the cell, the greater the osmotic gradient. To achieve equilibrium, this will suck water from the surrounding xylem. The newly formed sugar solution will impose a considerable turgor pressure on the Phloem walls. The turgor pressure causes the soluble sugar molecules to travel up the phloem tube, eventually reaching the sink organ.

As soon as the soluble sugar enters the sink, it is gathered by the component that requires it. The amount of water input from the xylem decreases as the sugar concentration decreases. As a result, the sink tissues are under pressure. As a result, the food material is constantly transferred across the plant sink organs, i.e. between higher and lower pressure zones.

Bidirectional flow in Phloem

As we all know, green plant parts synthesis food and serve as sources. Other non-green plant portions, such as roots, sink as they consume the nourishment transported by Phloem. Because the green leaves are part of the shoot system, they migrate from top to bottom.

However, the plant’s major food sources shed off in the early spring or autumn. The soluble carbohydrates found in the roots migrate upward to nourish the emerging buds and leaflets in this scenario. As a result, it is clear that phloem transport is bidirectional, i.e., from upward to downward and vice versa.

Key Differences Between Xylem and Phloem

  • The phloem is not divided into hard wood and soft wood, but the xylem is.
  • Xylem makes up most of the plant’s body, while phloem makes up most of the bark.
  • Phloem has long fibers and xylem has short ones.
  • The walls of Xylem cells are thick, while the walls of Phloem cells are thin.
  • Phloem only has one type of conducting cell, while xylem has two types.
  • Xylem’s conducting tissues are dead, while phloem’s are alive.
  • The outer vascular cambium is where the phloem is, and the inner vascular cambium is where the xylem is.
  • The xylem only moves in one direction, while the phloem moves in both directions.
  • Tyloses happen in xylem, but not often in phloem.
  • Xylem is found in a lot more plants than phloem.
  • Xylem can help support the plant’s structure, but phloem can’t.
  • The xylem is in charge of moving water and minerals, and the phloem is in charge of moving food.
  • The xylem is made up of dead cells, while the phloem is mostly made up of living cells with only a few dead cells.
  • Heartwood and sapwood are two different kinds of xylem. Phloem, on the other hand, is not different.
  • The phloem has sieve tubes, while the xylem has tracheids and vessels.
  • The cell walls of xylem are thick, while the cell walls of phloem are thin.
  • The phloem fibers are flexible and shorter, while the xylem fibers are strong and longer.
  • The roots, leaves, and stems all have xylem, while the leaves and stems have phloem.
  • The parts of phloem tissue are sieve tubes, companion cells, phloem fibers, and parenchyma. Xylem tissue is made up of xylem vessels, tracheids, and fibers.
  • Most of the plant’s body is made up of xylem, and most of the bark is made up of phloem.

Similarities

  • Both of them have cells that look like parenchyma.
  • Both of them have vascular tissue, which helps move materials around the plant.
  • Both the xylem and the phloem have cellulose in their cell walls.
  • Both xylem and phloem have chloroplasts in them.

FAQs

What is the function of xylem and?

Xylem is a special type of tissue in vascular plants that moves water and nutrients from the plant-soil interface to the stems and leaves. It also supports the plant and stores food. One of the most important things that sets vascular plants apart is that their xylem carries water.

Where are the xylem and phloem located in a plant?

Phloem is found in the bark of trees. It moves sugars and other organic compounds from the leaves to the rest of the plant. Xylem is the other type of vascular tissue in plants. The outer wood of trees is called xylem. It moves water from the roots to the leaves.

What is xylem and phloem with example?

Xylem helps move water and minerals from the root to other parts of the plant, such as the stem, leaves, and fruits. Phloem helps move food from the leaves, which make food, to other parts of the plant, like the stems, roots, and fruits. The parts of xylem are the xylem fiber, the vessels, the tracheids, and the parenchyma.

What is the role of phloem?

Through the sieve elements, the main job of phloem tissue is to move carbohydrates from sources to sinks. However, phloem is also made up of parenchyma cells, which are very important for storing water, non-structural carbohydrates, and storage proteins (Rosell 2016).

What is phloem and its function?

Phloem is the part of the plant’s blood vessels that moves and distributes organic nutrients. The phloem is a way for signaling molecules to get to other parts of the plant, and it also helps hold the plant together. Usually, it is made up of three types of cells: sieve elements, parenchyma, and sclerenchyma.

What is the role of xylem and phloem?

From the roots to the leaves, the xylem moves water and minerals that have been dissolved through the plant. The leaves send food to the roots through the phloem.

Conclusion

These are the two complicated parts of a plant’s vascular bundle that are very important to its life. Xylem is in charge of moving water and minerals from the roots, and phloem is in charge of moving food from the leaves.

So, all of these vascular vessels are just as important to a plant’s life. The above differences help you understand how each type of vessel works in its own way.