Editing Nutrient sensing (section)

==Nutrient sensing in plants==

Higher plants require a number of essential nutrient elements for completing their life cycles. Mineral nutrients are mainly acquired by roots from the [[rhizosphere]] and are subsequently distributed to shoots. To overcome with nutrient limitations, plants have evolved a set of elaborate responses consisting of sensing mechanisms and signaling processes to perceive and adapt to external nutrient availability.<ref name=Cui2012 />

Plants obtain most necessary nutrients by taking them up from the soil into their roots. Although plants cannot move to a new environment when nutrient availability is less than favorable, they can modify their development to favor root colonization of soil areas where nutrients are abundant. Therefore, plants perceive the availability of external nutrients, like nitrogen, and couple this nutrient sensing to an appropriate adaptive response.

===Types of nutrients in plants===

Potassium (K<sup>+</sup>) and phosphorus (P<sup>+</sup>) are important macronutrients for crops but are often deficient in the field. Very little is known about how plants sense fluctuations in concentrations of K<sup>+</sup> and P<sup>+</sup>, and how such sensing is integrated at the organismic level into physiological and metabolic adaptations.<ref>{{Cite web |last=Press |first=Cell |title=Getting to the root of nutrient sensing |url=https://phys.org/news/2010-06-root-nutrient.html |access-date=2023-12-30 |website=phys.org |language=en}}</ref><ref>{{Citation |last=Amtmann |first=Anna |title=Nutrient Sensing and Signalling in Plants: Potassium and Phosphorus |date=2005-01-01 |url=https://www.sciencedirect.com/science/article/pii/S0065229605430050 |work=Advances in Botanical Research |volume=43 |pages=209–257 |access-date=2023-12-30 |series=Incorporating Advances in Plant Pathology |publisher=Academic Press |last2=Hammond |first2=John P. |last3=Armengaud |first3=Patrick |last4=White |first4=Philip J.}}</ref> Smaller amounts of other [[Nutrient|micronutrients]] are also important for the growth of the crop. All of these nutrients are equally important for the growth of the plant and lack of one nutrient can result in poor growth of the plant as well as becoming more vulnerable to diseases or can lead to death.<ref name=":02">{{Cite web |date=2002 |title=What Nutrients do Plants need? |url=http://www.agroservicesinternational.com/Education/Fert1.html |url-status=dead |archive-url=https://web.archive.org/web/20210427071459/https://www.agroservicesinternational.com/Education/Fert1.html |archive-date=2021-04-27 |website=Agro Services International}}</ref> These nutrients along with {{CO2}} and energy from the sun aids in the development of the plant.<ref name=":12">{{Cite book |url=http://www.mhhe.com/biosci/genbio/raven6b/graphics/raven06b/other/raven06_39.pdf |archive-url=https://web.archive.org/web/20041122052625/http://www.mhhe.com/biosci/genbio/raven6b/graphics/raven06b/other/raven06_39.pdf |url-status=dead |archive-date=22 November 2004 |title=Higher Education Support {{!}} McGraw Hill Higher Education}}</ref>

===Nitrogen sensing===
As one of the most vital nutrients for the development and growth of all plants, [[nitrogen]] sensing and the signalling response are vital for plants to live.<ref>{{cite journal|last1=Kruok|first1=Gabriel|last2=Benoît|first2=Lacombe|last3=Agnieszka|first3=Bielach|last4=Perrine-Walker|first4=Francine|last5=Malinska|first5=Katerina|last6=Mounier|first6=Emmanuelle|last7=Hoyerova|first7=Klara|last8=Tillard|first8=Pascal|last9=Leon|first9=Sarah|last10=Ljung|first10=Karin|last11=Zazimalova|first11=Eva|title=Nitrate-Regulated Auxin Transport by NRT1.1 Defines a Mechanism for Nutrient Sensing in Plants|journal=Developmental Cell|date=June 15, 2010|volume=18|issue=6|pages=927–937|doi=10.1016/j.devcel.2010.05.008|pmid=20627075|doi-access=free}}</ref> Plants absorb nitrogen through the soil in the form of either [[nitrate]] or [[ammonia]].<ref name=":0">{{cite journal|last1=Ho|first1=Cheng-Hsun|last2=Tsay|first2=Yi-Fang|title=Nitrate, ammonium, and potassium sensing and signaling|journal=Current Opinion in Plant Biology|date=October 2010|volume=13|issue=5|pages=604–610|doi=10.1016/j.pbi.2010.08.005|pmid=20833581|doi-access=free}}</ref> In soil with low oxygen levels, ammonia is the primary nitrogen source, but toxicity is carefully controlled for with the transcription of ammonium transporters (AMTs).<ref name=":0" /> This metabolite and others including glutamate and glutamine have been shown to act as a signal of low nitrogen through regulation of nitrogen transporter gene transcription.<ref name=":1">{{Cite journal|last1=Coruzzi|first1=Gloria M|last2=Zhou|first2=Li|date=2001-06-01|title=Carbon and nitrogen sensing and signaling in plants: emerging 'matrix effects'|journal=Current Opinion in Plant Biology|volume=4|issue=3|pages=247–253|doi=10.1016/s1369-5266(00)00168-0|pmid=11312136}}</ref> NRT1.1, also known as CHL1, is the nitrate transceptor (transporter and receptor) found on the plasma membrane of plants.<ref name=":0" /> This is both a high and low affinity transceptor that senses varying concentrations of nitrate depending on its T101 residue phosphorylation.<ref name=":0" /> It has been shown that nitrate can also act as just a signal for plants, since [[mutants]] unable to metabolize are still able to sense the [[ion]].<ref name=":1" /> For example, many plants show the increase of nitrate-regulated genes in low nitrate conditions and consistent [[mRNA]] transcription of such genes in soil high in nitrate.<ref name=":1" /> This demonstrates the ability to sense nitrate soil concentrations without [[metabolic]] products of nitrate and still exhibit downstream genetic effects.<ref name=":1" />

=== Potassium Sensing ===
[[Potassium]] (K+), one of the essential [[Nutrient|macronutrients]] is found in plant soil. K+ is the most abundant cation and it is very limited in plant soil. Plants absorb K+ from the soil through channels that are found at the [[Plasma membrane Ca2+ ATPase|plasma membrane]] of root cells. Potassium is not assimilated into organic matter like other nutrients such as [[nitrate]] and [[ammonium]] but serves as a major osmoticum.<ref name=Cui2012>{{cite journal|title=Nutrient Sensing in Plants | doi=10.1093/mp/sss107 |pmid=23024206 | volume=5|issue=6 |journal=Molecular Plant|pages=1167–1169 | last1 = Cui | first1 = Xiaofeng|year=2012 |doi-access=free }}</ref>