Plant Tissue System

Plant tissue is a group of cells that work together to perform specific functions. In plants, these tissues, based on their structure and function, are organized into plant tissue systems, each dedicated to specialized functions. This article delves into the significance of plant tissues and their types including- meristematic, permanent, complex, and protective tissues, each with distinct characteristics and functions. The article also provides insights into the functions, structure, and differences among various plant tissues, highlighting their vital roles in agriculture, horticulture, and ecological studies.

What is Plant Tissue?

Plant tissue is an arrangement of similar cells that helps a plant body survive. The arrangement and organization of these tissues vary throughout different parts of the plant. These tissues are responsible for the plant’s growth, strength, and protection.

Types of Plant Tissues

Plant Tissues, based on their physical structure and functionality, can be grouped into- meristematic, permanent, complex, and protective tissues.

1. Meristematic Tissues
2. Permanent Tissues
3. Complex Tissues
4. Protective Tissues

Meristematic Tissues

These cells undergo continuous division, contributing to the increase in both- the length and girth of the plant. Upon maturation, these tissues have the ability to stretch, elongate, and differentiate into other types of tissues. Meristematic tissues can be categorized into three types: apical meristems, lateral meristems, and intercalary meristems.

• Apical Meristem: These tissues are found at the tips of shoots and roots, which aid in the increase of plant length.
• Lateral Meristem: These tissues are found at the radial fractions or a root. This meristem helps in the structural development of the plant.
• Intercalary Meristem: These tissues are located at certain points along the stems or internodes of plants. These meristems play a crucial role in plant growth and development, contributing to the lengthening and branching of the plant.

Permanent Tissues

These tissues are also known as non-meristematic tissues, consisting of cells that have undergone differentiation and have attained a permanent form and function. There are three kinds of permanent tissues – parenchyma, collenchyma, and sclerenchyma.

• Parenchyma: These consist of living cells polygonal in shape with a large vacuole in the center. The parenchyma tissues perform the following functions including storage, photosynthesis, and buoyancy (flotation of plant on water). Additionally, they have large intercellular spaces in between them.
• Collenchyma: These tissues consist of living cells and elongated in shape, and have no intercellular space between them. These provide mechanical support and flexibility; they allow different parts of the plant easy-bending properties.
• Sclerenchyma: This tissue is made up of dead cells that have lignin deposits on their cell wall. These provide the plant with mechanical strength thus aiding the plant to survive severe strains.

Complex Tissues

These tissues are made up of a combination of cell types. These cells work together to perform specialized functions. There are two types of complex tissues- xylem and phloem.

• Xylem: This tissue is vascular & mechanical in form. Its primary function is the transportation of water and minerals upwards from the roots to other parts of the plant also, the xylem functions in only one direction i.e. vertical. Its secondary function is to provide structural support. The xylem is composed of four components- tracheid, vessels, xylem parenchyma, and xylem fibers.
• Phloem: Unlike the xylem, the phloem is bidirectional i.e. it can function upwards as well as downwards. Phloem transports the food prepared via photosynthesis from the leaves to the whole plant body.

Protective Tissues

These tissues offer support to a plant. These are mainly of two types: cork and epidermis.

• Cork: This tissue is made up of dead cells and acts as an outer protective layer of the plant. Additionally, this tissue lacks intercellular gaps and is therefore impenetrable to gas and water molecules.
• Epidermis: Present in the outermost layer of the plant i.e. on flowers, roots, stem, etc., this layer protects the plant from physical damage. Epidermis tissues are covered with cuticle, a waxy, water-proof substance secreted by epidermal cells. Cuticle helps reduce evaporation of water from the plant and entry of pathogens thus protecting the plant from desiccation & infection.

Vascular Cambium

The vascular cambium is a meristematic tissue layer found in the stems and roots of many vascular plants, and is responsible for secondary growth or increase in girth. It is generally located between the xylem and phloem in the stem and vascular bundles of the root. The primary function of the vascular cambium is to produce secondary xylem (wood) and secondary phloem (inner bark), thereby contributing to secondary growth. In addition to the vascular cambium, several plants have a cork cambium (phellogen) that produces cork cells towards the exterior, forming the protective outer bark layer.

Conclusion – Plant Tissue

Plant tissues are fundamental building blocks that contribute to the structure, growth, and functionality of plants. These tissues, organized into various systems, play specific roles in supporting the plant’s overall well-being. The classification of plant tissues into meristematic, permanent, complex, and protective categories highlights their diverse functions and characteristics. Plant tissues put emphasis on the diverse cell types that can adapt and function together to sustain life and growth. Understanding these tissues provides valuable insights for researchers, scientists, and agriculturists alike, paving the way for advancements in agriculture, horticulture, and ecological studies.

FAQs on Plant Tissue System

In which parts of the Plant are Parenchyma, Collenchyma, and Sclerenchyma present?

Parenchyma cells are distributed throughout the plant, including the roots, stems, leaves, fruits. Collenchyma cells are located in the stems and leaves. Sclerenchyma cells are present in plant parts, such as the stems, roots, leaves.

What is the Difference between Collenchyma and Sclerenchyma?

Sclerenchyma cells have a thick, rigid secondary cell wall which is absent in collenchyma, and collenchyma cells are relatively flexible and can elongate as the plant grows while sclerenchyma cells are rigid and lack flexibility .

What is the Difference between Cork and Epidermis Tissue?

The cork and epidermis are both protective tissues in plants, but the cork is a specialized tissue found in the outer bark of woody plants, while the epidermis is the outermost layer in young plant organs, made up of living cells.

Where are Meristematic Tissues found?

Meristematic Tissue is present at all growth points, including the tips of roots, stems, and branches. Its function is to generate new cells that aid in the expansion of the plant’s body.

What Function Dead Tissues perform?

Dead tissues in plants provide support and protection. For example, the dead cells in the outer bark of trees, like cork cells, act as a protective barrier against physical damage, pathogens, and water loss.

What is the Plant Tissue?

Plant tissue refers to a group of similar cells that work together and contribute to a plant’s growth, development, support, and protection.

Who Discovered Tissue?

Xavier Bichata, a French anatomist and pathologist, discovered tissues in 1801. He suggested that tissues play a crucial role in human anatomy, determining that organs are essentially comprised of various distinct tissues.