Materials for transportation in plants - SS2 Biology Lesson Note

The plant transport system, which consists of xylem and phloem tissues, transports various materials throughout the plant. Here are the main materials transported by the plant transport system:

1.       Water: The xylem tissue primarily transports water from the roots to the rest of the plant. This water is essential for photosynthesis, cell turgidity, and nutrient uptake.

2.       Nutrients and Minerals: Along with water, the xylem also transports dissolved nutrients and minerals absorbed by the roots. These include essential elements such as nitrogen, phosphorus, potassium, calcium, and magnesium, which are necessary for plant growth and development.

3.       Sugars: The phloem tissue transports sugars, primarily in the form of sucrose, from the sites of photosynthesis (usually leaves) to other parts of the plant where they are used for energy production, growth, and storage. This movement of sugars is known as translocation.

4.       Amino Acids: Along with sugars, the phloem transports amino acids, which are the building blocks of proteins. Amino acids are either produced during photosynthesis or obtained from the breakdown of proteins in leaves, and they are transported to growing regions or storage tissues.

5.       Hormones: The plant transport system also moves hormones throughout the plant. Hormones, such as auxins, gibberellins, cytokinins, and abscisic acid, regulate various physiological processes, including growth, development, flowering, and stress responses.

6.       Defense Signals: The plant transport system can transport signaling molecules involved in defense responses. When a part of the plant is attacked by pests or pathogens, defense signals can be transported to other parts of the plant to trigger defense mechanisms.

It's important to note that while water, nutrients, sugars, amino acids, hormones, and defense signals are the main materials transported by the plant transport system, other substances like lipids, gases (such as oxygen and carbon dioxide), secondary metabolites, and signaling molecules can also be transported to fulfill various physiological functions within the plant.