Editing Symplast

{{Short description|Interconnected intracellular space of a plant}}
{{expert|Plants|reason=multiple errors of fact and interpretation|date=April 2023}}
{{Refimprove|date=March 2016}}
[[Image:Apoplast and symplast pathways.svg|thumb|300px|The apoplastic and symplastic pathways]]
The '''symplast''' of a [[plant]] is the region enclosed by the [[cell membrane]]s, within which water and [[solutes]] can [[diffusion|diffuse]] freely. 
By contrast the [[apoplast]] is any fluid-filled space within the cell wall and extracellular space.<ref>{{Cite book |title=Biological Science |last=Freeman |first=Scott |publisher=Benjamin Cummings |year=2014 |isbn=9780321743671 |location=Boston}}</ref> Neighbouring cells are interconnected by microscopic channels known as [[Plasmodesma|plasmodesmata]] that traverse the cell walls. These channels, allow the flow of small molecules such as sugars, amino acids, and ions between cells (from the inner part of one cell to the inner part of the next cell). Larger molecules, including [[transcription factor]]s and [[plant virus]]es, can also be transported through with the help of [[actin]] structures. The symplast allows direct cytoplasm-to-cytoplasm flow of water and other nutrients along [[concentration gradients]]. In particular, symplastic flow is used in the root systems to bring in nutrients from soil.{{clarification needed|reason=how does it achieve this?|date=April 2023}} Nutrient solutes move in this way through three skin layers of the roots: from cells of the [[epidermis (botany)|''epidermis'']], the outermost layer, through the [[cortex (botany)|''cortex'']] into the ''[[endodermis]]''. 

Once solutes in the soil water reach the endodermal cells through [[Apoplast|apoplastic flow]], they are forced into the symplastic pathway due to the presence of the [[Casparian strip]]. Once the solutes are passively filtered{{clarification needed|reason=by what are they filtered?|date=April 2023}}, they eventually reach the [[pericycle]], where they can be moved into the [[xylem]] for long-distance transport.

==History==
Symplastic transport was first realized by Eduard Tangl in 1879, who also discovered [[plasmodesmata]],<ref>{{cite journal |last1=Köhler |first1=Piotr |last2=Carr |first2=Denis J. |title=Eduard Tangl (1848-1905) - discoverer of plasmodesmata. |journal=[[Huntia (journal)|Huntia]] |date=2006 |volume=12 |issue=2 |pages=169–172}}</ref> a term coined by [[Eduard Strasburger]], 1901.<ref>Tangl, E. (1879). Ueber offene Communicationen zwischen den Zellen des Endosperms einiger Samen. ''Jahrbüecherfüer Wissenschaftliche Botanik'' 12: 170–190.</ref><ref>Strasburger, E. (1901). Über plasmaverbindungen pflanzlicher zellen. ''Jahrbücher für Wissenschaftliche Botanik'' 36: 493–610.</ref> In 1880, [[Johannes von Hanstein|Hanstein]] coined the term symplast.<ref>Hanstein, J. 1880. ''[https://archive.org/details/DasProtoplasma Das Protoplasma]''. Heidelberg.</ref> The contrasting terms apoplast and symplast were used together in 1930 by [[Ernst Münch|Münch]].<ref>Münch, E (1930). ''Die Stoffbewegungen in der Pflanze''. Verlag von Gustav Fischer, Jena.</ref><ref>Pickard, W. F. (2003). The role of cytoplasmic streaming in symplastic transport. ''Plant, Cell & Environment'' 26: 1-15, [http://onlinelibrary.wiley.com/doi/10.1046/j.1365-3040.2003.00845.x/full].</ref>

==References==
{{reflist}}

==See also==
*[[Apoplast]]
*[[Plant sap]]
*[[Polar auxin transport]], a type of cell-to-cell transport 
*[[Protoplast]]
*[[Tonoplast]]

[[Category:Plant anatomy]]


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