How the process of transportation is useful to plants?
Answers
Explanation:
Transportation is a vital process in plants. Trees transport all the nutrients and water it needs for survival from its roots to the tips of the leaves.
In the case of transportation in plants, the biggest constraint is water as it ends up being a limiting factor in growth. To overcome this problem, trees and other plants have the perfect system for the absorption and translocation of water.
Plants contain a vast network of conduits which consist of xylem and phloem. This is more like the circulatory system that transports blood throughout the human body. Similar to the circulatory system in humans, the xylem and phloem tissues extend throughout the plant. These conducting tissues originate from the roots and move up through the trunks of trees. Later they branch off into the branches and then branching even further into every leaf, like spider webs.
Transportation occurs in three levels in the case of plants:
Transportation of substance from one cell to another.
Long-Distance transport of sap within phloem and xylem.
The release and uptake of solute and water by individual cells.
Let us have a detailed look at the process of absorption and transportation in plants.
Also Read: Difference between Tracheids and Vessels
Water Absorption In Plants
The water is absorbed in two ways by the plants:
In the case of active absorption, water moves through symplast and it is absorbed according to the Diffusion Pressure Deficit changes. The rate of absorption is slow. It comprises of osmotic and non-osmotic forces.
The rate of absorption does not significantly depend on humidity and temperature. It mainly depends on humidity and temperature. The force required for the absorption of water mainly generated in the root cells itself. There would be a decrease in the rate of water absorption if the metabolic inhibitors are applied.
Passive Absorption
The rate of absorption is fast. It occurs in rapidly transpiring plants. The movement of plants is through apoplast and it is absorbed due to transpiration pull and it is created due to the stress created in xylem sap. The rate of absorption significantly depends upon the rate of transpiration. The force required for the absorption of water mainly generated in the mesophyll cells.
Also Read: Difference between active and passive transport
Transportation in Plants
The water and minerals are transported in plants by two types of conducting tissues:
Xylem
Phloem
Xylem
Xylem is a long, non-living tube running from the roots to the leaves through the stem. The water is absorbed by the root hair and undergoes cell to cell movement by osmosis until it reaches the xylem. This water is then transported through the xylem vessels to the leaves and is evaporated by the process of transpiration.
The xylem is also composed of elongated cells like the phloem. However, xylem is especially accountable for transporting water to all parts of the plants from the roots. Since they serve such an important function, a single tree would have a lot of xylem tissues.
Phloem
The phloem is responsible for translocation of nutrients and sugar like carbohydrates, produced by the leaves to areas of the plant that are metabolically active. It is made up of living cells. The cells walls of these cells form small holes at the ends of the cells known as sieve plates