Introduction

Plants rely heavily on water to survive and thrive. Water is known to reach various parts of a plant via a mechanism called diffusion. Diffusion is the movement of molecules from an area of high concentration to an area of low concentration. In the case of plants, it is the movement of water from a region of higher concentration of water to an area of lower concentration. The following discussion will outline the various ways in which the process of diffusion moves water within a plant.

Diffusion through Roots

The first stage of water movement in plants occurs when the concentration of water within the soil is greater than that within the plant. Water then flows into the plant through the roots, in a process referred to as osmosis. Osmosis is a subset of diffusion, whereby water molecules move from a region of high concentration to an area of low concentration through a semi-permeable membrane, in this case, the root surface. The plant root is much like a sponge, and it absorbs the water until the concentration of water inside the plant is equal to that outside.

Diffusion through Xylem

The next stage of water movement is through the plant's xylem. The xylem is the plant's system of tubes that run from the roots to the rest of the plant. Water moves through the xylem via a suction mechanism created by transpiration, which is the process of water loss from the leaves. When water evaporates from the leaves, it creates a suction force that pulls water up from the roots, through the xylem, and into the stem and leaves. This process continues as long as the concentration of water in the leaves is less than that within the xylem.

Diffusion through Capillary Action

Capillary action is yet another mode of water movement in plants. Capillary action results from the adhesion of water molecules to the xylem walls, which means that the water molecules will "stick" to the walls of the tubes. Through this process, the water molecules form a chain-like structure that stretches from the roots to the leaves. As the chain of water molecules moves upwards due to the suction force of transpiration, the water in the xylem pulls through the chain of molecules, almost like a straw, until it reaches the places where it is needed in the plant.

Conclusion

Water is literally the life of a plant, and without it, a plant cannot survive. Fortunately, diffusion ensures that water will flow within a plant from regions of high concentrations to areas of lower concentrations. Diffusion happens at different stages of a plant's growth cycle, through roots, xylem, and capillary action. Understanding how diffusion moves water through a plant is essential to grow healthy plants and increase yields in agriculture.