In this article, we will consider what root pressure is and its effect on plants. All plant life, even the tallest trees, has gravitational properties that allow nutrients to be absorbed from the deepest soil depths and transported to the highest branches. We will consider that plants have an amazing ability to transport water and nutrients upwards using a complex set of biological processes.
The concept of root pressure
Let's consider what root pressure is, definition. This is the force that helps push fluids up into the water vessels (xylems). Xylem is the plant's vascular tissue that transfers water and dissolved minerals from the roots to the rest of the plant, as well as providing physical support. The xylem is made up of many specialized water-conducting cells. She is basicallygenerated by osmotic pressure in root cells.
Water spreading into the roots from the surrounding soil rises through the trunk and branches of the tree before penetrating the leaves. The pressure on the trees is several times higher than atmospheric pressure. And this is not enough to carry water to the top of the tallest trees. In addition, root pressure tends to be lowest at leaf water loss (transpiration) and is highest when trees need water the most.
The lifting force generated by the evaporation and transpiration of water from leaves, as well as the cohesive forces of molecules in vessels and possibly other factors contribute to the growth of sap in plants.
Pressure of the root system of plants. Details
Not everyone knows what root pressure is. Plants are complex organisms, and one of the many intriguing processes of a plant is root pressure. It is this that allows water and nutrients to rise to all parts of the plant. So what is root pressure? It is necessary in order to promote or hinder the absorption of nutrients.
In other words, the root system of a plant can change its pressure:
- help water or nutrients rise throughout the plant;
- push water or nutrients out of the plant.
Biologists are usually concerned about how this affects the rise of water and nutrients in the plant. Root pressure istransverse osmotic pressure in the cells of the root system. It causes the juice to rise through the stem of the plant to the leaves.
Operation principle
What is root pressure and how does it appear? It occurs in the xylem of vascular plants when soil moisture levels are high, either at night or when transpiration is low during the day. It is studied by removing the shoot of the plant near the soil level. Xylem sap will ooze out of the cut within hours or days due to root pressure. If a manometer is attached to the cut stem, the root pressure can be measured. Root pressure is due to the active distribution of mineral nutrient ions into the root xylem.
It is caused by the accumulation of water in the xylem. This water puts pressure on the cells. Root pressure provides the force that pushes water up the stem, but not enough to account for the movement of water towards the leaves at the top of the tallest trees. The maximum root pressure measured in some plants can only raise water up to 6.87 meters. And the tallest trees - over 100 meters.
Root pressure value
Root pressure is very important in plants of any size, as the endoderm - the inner layer of cortex cells - will only transport water and nutrients up the stem or stem of the plant. Water and nutrients are taken up by the root system from the ground and driven by osmosis combined with pressure from the root system up the stem of the plant. Further, nutrients and water are sent to the leaves.plants to provide the raw materials needed for the photosynthesis process.
During photosynthesis, water and carbon dioxide are absorbed by the radiant energy of the sun to produce glucose, necessary for the life processes of plant cells. Generally, the larger the plant, the greater the root pressure. Plants such as trees can reach hundreds of meters in height, so increased root pressure is needed to get water and nutrients to the topmost areas of the tree.
