Supporting Tissues In Plants - SS1 Biology Lesson Note

Plants have various supporting tissues that provide structural support and stability to different parts of the plant. These tissues help the plant withstand mechanical stress, maintain its shape, and allow for upright growth. Here are some of the main supporting tissues in plants:

1.     Parenchyma: Parenchyma cells are the most common type of plant cells and are involved in many functions, including support. In some plants, specifically in herbaceous plants, the parenchyma cells in the cortex and pith regions provide support by maintaining turgidity.

2.     Collenchyma: Collenchyma cells are elongated cells with thickened cell walls. They provide flexible support to young plant organs, such as stems and petioles. Collenchyma cells are particularly abundant in regions where active growth occurs, such as the growing tips of stems and the undersides of leaf veins.

3.     Sclerenchyma: Sclerenchyma cells are highly specialized cells with thick, lignified cell walls. They provide rigid support and strength to mature plant parts. Sclerenchyma cells can be of two types:

a.     Sclereids: Sclereids are short, irregularly shaped cells that provide localized support. They are found in hard tissues like seed coats and fruit shells.

b.     Fibers: Fibers are long, slender cells that occur in groups or bundles. They provide support to plant tissues, such as the vascular bundles in stems and the phloem sieve tubes.

4.     Xylem: Xylem is a complex tissue responsible for conducting water, minerals, and providing structural support in plants. The thick-walled cells of xylem, known as tracheary elements, are involved in water transport and contribute to the rigidity of plant organs.

5.     Phloem: Phloem is another complex tissue involved in the transport of organic compounds, such as sugars, throughout the plant. The sieve elements in the phloem, including sieve tube elements and companion cells, play a role in structural support in addition to their transport functions.

These supporting tissues work together to provide strength, rigidity, and flexibility to different parts of the plant, ensuring that they can withstand environmental conditions and maintain their shape and function.

 

Figure 68 image from itsmyschoollibrary.com