Editing Abiotic stress (section)

=== Salt stress in plants ===
Soil salinization, the accumulation of water-soluble salts to levels that negatively impact plant production, is a global phenomenon affecting approximately 831 million hectares of land.<ref>Martinez-Beltran J, Manzur CL. (2005). Overview of salinity problems in the world and FAO strategies to address the problem. Proceedings of the international salinity forum, Riverside, California, April 2005, 311–313.</ref> More specifically, the phenomenon threatens 19.5% of the world's irrigated agricultural land and 2.1% of the world's non-irrigated (dry-land) agricultural lands.<ref name=":0">{{Cite journal|last1=Neto|first1=Azevedo|last2=De|first2=André Dias|last3=Prisco|first3=José Tarquinio|last4=Enéas-Filho|first4=Joaquim|last5=Lacerda|first5=Claudivan Feitosa de|last6=Silva|first6=José Vieira|last7=Costa|first7=Paulo Henrique Alves da|last8=Gomes-Filho|first8=Enéas|date=2004-04-01|title=Effects of salt stress on plant growth, stomatal response and solute accumulation of different maize genotypes|journal=Brazilian Journal of Plant Physiology|volume=16|issue=1|pages=31–38|doi=10.1590/S1677-04202004000100005|issn=1677-0420|doi-access=free}}</ref> High [[soil salinity]] content can be harmful to plants because water-soluble salts can alter osmotic potential gradients and consequently inhibit many cellular functions.<ref name=":0" /><ref>Zhu, J.-K. (2001). Plant Salt Stress. eLS.</ref> For example, high soil salinity content can inhibit the process of photosynthesis by limiting a plant's water uptake; high levels of water-soluble salts in the soil can decrease the osmotic potential of the soil and consequently decrease the difference in water potential between the soil and the plant's roots, thereby limiting electron flow from H<sub>2</sub>O to P680 in [[Photosystem II|Photosystem II's]] reaction center.<ref>Lu. Congming, A. Vonshak. (2002). Effects of salinity stress on photosystem II function in cyanobacterial Spirulina platensis cells. Physiol. Plant 114 405-413.</ref>

Over generations, many plants have mutated and built different mechanisms to counter salinity effects.<ref name=":0" /> A good combatant of salinity in plants is the hormone [[ethylene]]. Ethylene is known for regulating plant growth and development and dealing with stress conditions. Many central membrane proteins in plants, such as ETO2, ERS1 and EIN2, are used for ethylene signaling in many plant growth processes. Mutations in these proteins can lead to heightened salt sensitivity and can limit plant growth. The effects of salinity has been studied on ''[[Arabidopsis]]'' plants that have mutated ERS1, ERS2, ETR1, ETR2 and EIN4 proteins. These proteins are used for ethylene signaling against certain stress conditions, such as salt and the ethylene precursor ACC is used to suppress any sensitivity to the salt stress.<ref>{{Cite journal|last1=Lei|first1=Gang|last2=Shen|first2=Ming|last3=Li|first3=Zhi-Gang|last4=Zhang|first4=Bo|last5=Duan|first5=Kai-Xuan|last6=Wang|first6=Ning|last7=Cao|first7=Yang-Rong|last8=Zhang|first8=Wan-Ke|last9=Ma|first9=Biao|date=2011-10-01|title=EIN2 regulates salt stress response and interacts with a MA3 domain-containing protein ECIP1 in Arabidopsis|journal=Plant, Cell & Environment|language=en|volume=34|issue=10|pages=1678–1692|doi=10.1111/j.1365-3040.2011.02363.x|pmid=21631530|issn=1365-3040|doi-access=free|bibcode=2011PCEnv..34.1678L }}</ref>