Transfer cells are specialized
parenchyma cells that have an increased
surface area
The surface area of a solid object is a measure of the total area that the surface of the object occupies. The mathematical definition of surface area in the presence of curved surfaces is considerably more involved than the definition of arc ...
, due to infoldings of the
plasma membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (t ...
. They facilitate the transport of sugars from a sugar source, mainly mature leaves, to a sugar sink, often developing leaves or fruits. They are found in nectaries of flowers and some carnivorous plants.
Transfer cells are specially found in plants in the region of absorption or secretion of nutrients.
[Stern's Introductory Plant Biology, 13th Ed. Bidlack, James E., and Jansky, Shelley H. p. 56]
The term transfer cell was coined by
B. E. S. Gunning and J. S. Pate. Their presence is generally correlated with the existence of extensive solute influxes across the plasma membrane.
References
Plant cells
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