Phloem Tissue
4 Minutes
Phloem tissue in plants for kids: learn how companion cells, sieve elements, fibers, and parenchyma transport food. An English science lesson.
- How phloem carries food from leaves to plant parts like roots
- The roles of companion cells and sieve elements in delivery
- How phloem fibers provide support and parenchyma stores food
What this lesson teaches
Phloem tissue is a specialized plant tissue located in the inner bark that carries food prepared in the leaves to other parts of the plant, such as the roots, stems, flowers, and fruits. It is made of four distinct parts that coordinate to power, transport, support, and store nutrients like glucose.
The four parts of phloem
- Companion cells are living, spindle-shaped cells attached to sieve elements that decide where food must go and supply the energy needed for transport.
- Sieve elements are living cells shaped like household strainers that act as delivery pathways to carry glucose to various plant parts.
- Phloem fibers provide strong physical support to both the sieve elements and the whole tree, forming a clear path for food movement.
- Phloem parenchyma cells are living storage cells that keep reserve food safe whenever plant organs receive more glucose than they can immediately use.
How food moves through the plant
Leaves make glucose through the process of photosynthesis, but other parts of the plant, including roots, stems, flowers, and fruits, cannot make their own food. To receive nourishment, these parts depend on phloem tissue to deliver glucose from the leaves. Companion cells coordinate the delivery process by supplying energy and directing where the food should travel. Sieve elements then carry the glucose along supportive fiber pathways directly to the destination, ensuring the plant stays properly nourished.
Food storage in parenchyma cells
Plants do not waste the food delivered to their different parts. When glucose reaches an organ like a root, the root consumes only the exact amount of food it needs to function. The remaining unused food is transferred to phloem parenchyma cells, which act like storage units for future survival. These living parenchyma cells allow the plant to hold on to valuable nutrients rather than letting them go to waste.
Phloem fibers and their uses
Phloem fibers provide the rigid structural support needed by sieve elements to transport nutrients smoothly without disruption. In addition to assisting the transport system, these tough fibers provide structural support to the whole tree. Because phloem fibers are durable and flexible, humans harvest them from plants like flax and jute to produce everyday materials, such as the jute ropes used to tie rice sacks.