Companion cells

Companion cells move sugars and amino acids into and out of the sieve elements.

companion cells Specialized cells in the phloem that load sugars into the sieve elements and help maintain a functional plasma membrane in the sieve elements. PICTURE 1 PICTURE 2 ...

companion cells
A type of plant cell that is connected to a sieve-tube member, making up the phloem tissue.

[edit] Companion Cells
The survival of sieve-tube members depends on a close association with the companion cells.

Companion cells load sugar into the sieve element (sieve elements are connected into sieve tubes). Fluids can move up or down within the phloem, and are translocated from one place to another. Sources are places where sugars are being produced.

Phloem tissue consists of sieve-tube members and companion cells . The sieve-tube elements are large, cylindrical cells, with large pores in the cell wall at either end. They are almost entirely dead, and have no organelles.

phloem. The food-conducting tissue of a plant, made up of sieve tubes, companion cells, phloem parenchyma, and fibers.
phloem-feeding. An organism that withdraws nutrients from the food-conducting tissue of a plant's vascular system.

phloem - living conducting tissue of a plant, a system basically composed of sieve tubes, companion cells, fibers and sclereids to convey the products of photosynthesis, particularly sucrose, from the leaves to growing tissues.

See also: Xylem, Tissue, Cells, Trans, Phloem