QUESTION: Which tissue transport food in plants?
ANS:
- Phloem tissue transports food in plants
- It consists of several types of specialized cells, including sieve tube elements, companion cells, phloem fibers, and phloem parenchyma cells.
- Phloem tissue transports sugars, mainly sucrose, produced during photosynthesis in the leaves to other parts of the plant, including growing tissues, storage organs (such as roots and tubers), and reproductive structures (such as flowers and fruits).
- Phloem also transports other organic compounds, such as amino acids, hormones, and signaling molecules, ensuring their distribution to various parts of the plant where they are needed.
| Phloem tissue | Information |
| Composition | · Sieve tube elements
· Companion cells · Phloem fibers · Phloem parenchyma cells |
| Function | · Transport of sugars produced during photosynthesis, as well as other organic compounds, from source regions (e.g., leaves) to sink regions (e.g., growing tissues, storage organs and reproductive structures) throughout the plant. |
| Transport mechanism | · The movement of sugars and nutrients in the phloem is driven by the pressure flow hypothesis, where sugars are actively loaded into sieve tube elements at source regions and transported via osmotic pressure gradients towards sink regions, where they are actively unloaded. |
| Sugar transport | · The main sugar transported in the phloem is sucrose, which is produced during photosynthesis in source regions and transported to support growth, storage, and reproductive processes in sink regions. |
| Nutrient distribution | · In addition to sugars, phloem tissue transports amino acids, hormones, signaling molecules, and other organic compounds, ensuring their distribution to various parts of the plant where they are needed. |
| Research areas | · Scientists study phloem tissue to understand its role in nutrient transport, signaling, interactions with other plant systems, responses to stress and pests, and its potential applications in areas such as crop improvement and plant engineering. |