Diagram of Phloem Tissue (original) (raw)

Last Updated : 23 Jul, 2025

The Diagram of Phloem Tissue helps us understand the structure and function of the phloem tissue. Phloem tissue is a vascular plant tissue responsible for transporting sugars, amino acids, and other organic nutrients. The labelled diagram of phloem tissue shows that it consists of sieve tube elements, companion cells, and phloem parenchyma. The phloem plays an essential role in the distribution of nutrients throughout the plant. In this article, we will learn about the phloem tissue and its structure with the help of a diagram of the phloem.

Table of Content

What is Phloem Tissue?

**Definition of Phloem: A phloem is a vascular tissue in plants that transports nutrients and minerals throughout the plant.

Pholem is one of the two conducting tissues in plants and comprises of four main cell types: **sieve tubes, companion cells, fibers, and parenchyma cells. Sieve tubes, connected by sieve plates, form the primary channels for nutrient flow. Companion cells, closely associated with sieve tubes, provide support and help in metabolic functions. Fibers provide structural support, while parenchyma cells store and metabolize various substances. This complex network enables the bidirectional movement of sap, playing an essential role in nutrient distribution and overall plant growth.

Also Read: Types of Plant Tissue System and their Functions

Labelled Diagram of Phloem

The longitudinal section of phloem tissue diagram is given below:
Structure-of-Phloem-Diagra,

Structure of Phloem Tissue

The phloem is a specialized vascular tissue in plants. It is **responsible for the transport of organic nutrients, primarily sugars, from the site of photosynthesis to other parts of the plant. The diagram of phloem shows the structure as follows:

  1. **Sieve Tubes: Sieve tubes are the primary cells responsible for transporting nutrients.
    • They are elongated, tube-like structures with perforated end walls called sieve plates.
    • Sieve tubes lack a nucleus, ribosomes, and a vacuole. It form a continuous channel for efficient sap flow.
    • The sieve plates allow the movement of sap from one sieve tube to another.
  2. **Companion Cells: Companion cells are closely associated with sieve tubes. It provide essential support and metabolic functions.
    • They contain a nucleus and numerous organelles that supports the metabolic needs of both the companion cell and the adjacent sieve tube.
    • **Plasmodesmata connects the sieve tubes to companion cells. It carry out the exchange of substances.
  3. **Parenchyma Cells: Parenchyma cells are loosely packed, living cells with a variety of functions.
    • They store and metabolize various substances, including starch and lipids.
    • Parenchyma cells are involved in the **repair and regeneration of phloem tissue.
  4. **Fibers: Fibers are long, slender cells that provide **structural support to the phloem.
    • They are often found on the outer side of the phloem. It add strength to the tissue.
    • The fibers provides rigidity and strength to the plant.
  5. **Phloem Parenchyma: Phloem parenchyma cells are specialized parenchyma cells associated with the phloem.
    • They play a role in **nutrient storage, particularly in the form of starch grains.
    • Phloem parenchyma cells may also be involved in the **repair and regeneration of phloem tissue.

Also Read: Difference Between Xylem And Phloem

Phloem Function

Phloem functions primarily in transport of sugars. The various other phloem functions are given below:

  1. Phloem is primarily responsible for the **transport of organic nutrients, such as sugars produced through photosynthesis, from leaves to areas of active growth or storage in the plant.
  2. Phloem parenchyma cells **store surplus nutrients and can redistribute them to other parts of the plant when needed. It help in maintaining the overall nutrient balance.
  3. Companion cells associated with sieve tubes in the phloem **provide metabolic support. It ensure the energy and resources required for efficient nutrient transport.
  4. Phloem sap contains signaling molecules that can convey information over long distances within the plant. It help coordinate responses to environmental changes or stress.
  5. Phloem **facilitates the transport of plant hormones, such as **auxins and gibberellins. It regulates various physiological processes such as growth, development, and response to environmental stimuli.
  6. Some components in the phloem sap, including secondary metabolites and defensive proteins, **contribute to the plant's defense against pathogens by deterring or inhibiting the activities of herbivores or microorganisms.

Also Read: Difference Between Auxin and Gibberellin

Conclusion: Diagram of Phloem Tissue

In conclusion, the diagram of phloem tissue helps us fully understand its structure. Phloem in vascular plants facilitates the transport of organic nutrients, primarily sugars, from photosynthetic sources to other plant parts through the process of **translocation. Phloem cells include sieve elements, companion cells, and parenchyma cells. The phloem tissue functions in the distribution of essential nutrients throughout the plant, supporting growth and metabolic processes.

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