sieve tube
Noun: A sieve tube is a tube formed by a vertical series of elongated plant cells (sieve-tube elements) joined end-to-end. These cells have perforated end walls (sieve plates) that allow nutrients, primarily sugars produced by photosynthesis, to flow through them. Sieve tubes are the main conducting elements of the phloem tissue in vascular plants, responsible for transporting organic nutrients throughout the plant.
Sieve tubes are a specific anatomical structure found in the phloem of flowering plants (angiosperms) and brown algae. * The sieve tube is essential for the long-distance transport of sugars from leaves to roots and fruits. * Damage to the sieve tubes can disrupt the flow of nutrients within the plant.
- In a leaf, sugars are loaded into the sieve tubes for distribution to the rest of the plant.
- The functioning of a sieve tube relies on living companion cells adjacent to it.
- Researchers studied the flow rate within the sieve tube to understand phloem transport.
- Sieve-tube element: Refers to an individual cell that makes up part of a sieve tube. These cells lose their nuclei at maturity but remain alive and metabolically active.
- Sieve plate: The perforated end wall of a sieve-tube element where the cells connect, allowing cytoplasmic continuity and flow between elements.
- Phloem (noun): The vascular plant tissue in which sieve tubes are found. It is responsible for transporting sugars and other metabolic products.
- Companion cell (noun): A specialized parenchyma cell associated with a sieve-tube element, believed to regulate its activity and provide metabolic support.
- Phloem conduit (a more general term for a channel within the phloem).
The term "sieve tube" is highly specific to botany and plant anatomy. It does not have common alternative meanings in general English. It should not be confused with "xylem vessel," which is a tube for water transport in plants.
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tube formed by cells joined end-to-end through which nutrients flow in flowering plants and brown algae
