Editing Sodium (section)

=== Biological role in plants ===
In [[C4 plants]], sodium is a [[micronutrient]] that aids metabolism, specifically in regeneration of [[phosphoenolpyruvic acid|phosphoenolpyruvate]] and synthesis of [[chlorophyll]].<ref>{{cite web|last=Kering|first=M. K.|url=https://mospace.umsystem.edu/xmlui/bitstream/handle/10355/7201/research.pdf?sequence=3|title=Manganese Nutrition and Photosynthesis in NAD-malic enzyme C4 plants PhD dissertation|publisher=University of Missouri-Columbia|date=2008|access-date=9 November 2011|archive-date=25 April 2012|archive-url=https://web.archive.org/web/20120425152651/https://mospace.umsystem.edu/xmlui/bitstream/handle/10355/7201/research.pdf?sequence=3|url-status=live}}</ref> In others, it substitutes for [[potassium]] in several roles, such as maintaining [[turgor pressure]] and aiding in the opening and closing of [[stoma]]ta.<ref>{{cite journal|last1=Subbarao|first1=G. V.|last2=Ito|first2=O.|last3=Berry|first3=W. L.|last4=Wheeler|first4=R. M.|title=Sodium—A Functional Plant Nutrient|journal=Critical Reviews in Plant Sciences| volume=22| pages=391–416| date=2003|doi=10.1080/07352680390243495|issue=5|s2cid=85111284}}</ref> Excess sodium in the soil can limit the uptake of water by decreasing the [[water potential]], which may result in plant wilting; excess concentrations in the [[cytoplasm]] can lead to enzyme inhibition, which in turn causes necrosis and chlorosis.<ref>{{cite journal| last1=Zhu|first1=J. K.|title=Plant salt tolerance|journal=Trends in Plant Science|volume=6|issue=2|pages=66–71|date=2001|pmid=11173290|doi=10.1016/S1360-1385(00)01838-0|bibcode=2001TPS.....6...66Z }}</ref>

In response, some plants have developed mechanisms to limit sodium uptake in the roots, to store it in cell [[vacuole]]s, and restrict salt transport from roots to leaves.<ref name="halo">{{cite web|url=http://www.plant-biology.com/salt-ion-toxicity.php|title=Plants and salt ion toxicity|publisher=Plant Biology|access-date=2 November 2010|archive-date=3 April 2012|archive-url=https://web.archive.org/web/20120403032507/http://www.plant-biology.com/salt-ion-toxicity.php|url-status=live}}</ref> Excess sodium may also be stored in old plant tissue, limiting the damage to new growth. [[Halophytes]] have adapted to be able to flourish in sodium rich environments.<ref name="halo" />