Editing Reactive oxygen species (section)

==Biological function==
In a biological context, ROS are byproducts of the normal metabolism of [[oxygen]]. ROS have roles in [[cell signaling]] and [[homeostasis]].<ref>{{Cite journal |last1=Apel |first1=Klaus |last2=Hirt |first2=Heribert |date=2004 |title=Reactive Oxygen Specues: Metabolism, Oxidative Stress, and Signal Transduction |journal=Annual Review of Plant Biology |volume=55 |issue=1 |pages=373–399 |doi=10.1146/annurev.arplant.55.031903.141701 |pmid=15377225|bibcode=2004AnRPB..55..373A }}</ref><ref name="ReferenceB">{{Cite journal |vauthors=Waszczak C, Carmody M, Kangasjärvi J |date=April 2018 |title=Reactive Oxygen Species in Plant Signaling |journal=Annual Review of Plant Biology |volume=69 |issue=1 |pages=209–236 |doi=10.1146/annurev-arplant-042817-040322 |pmid=29489394 |doi-access=free|bibcode=2018AnRPB..69..209W }}</ref><ref name="Devasagayam 2004 796">{{Cite journal |vauthors=Devasagayam TP, Tilak JC, Boloor KK, Sane KS, Ghaskadbi SS, Lele RD |date=October 2004 |title=Free radicals and antioxidants in human health: current status and future prospects |journal=The Journal of the Association of Physicians of India |volume=52 |pages=794–804 |pmid=15909857}}</ref><ref>{{Cite journal |vauthors=Edreva A |date=2 April 2005 |title=Generation and scavenging of reactive oxygen species in chloroplasts: a submolecular approach |url=https://www.sciencedirect.com/science/article/pii/S0167880904002889 |journal=Agriculture, Ecosystems & Environment |language=en |volume=106 |issue=2 |pages=119–133 |bibcode=2005AgEE..106..119E |doi=10.1016/j.agee.2004.10.022 |issn=0167-8809 |access-date=3 November 2020}}</ref> ROS are intrinsic to cellular functioning, and are present at low and stationary levels in normal cells.<ref>{{Cite journal |vauthors=Herb M, Gluschko A, Schramm M |date=September 2021 |title=Reactive Oxygen Species: Not Omnipresent but Important in Many Locations |journal=Frontiers in Cell and Developmental Biology |volume=9 |pages=716406 |doi=10.3389/fcell.2021.716406 |pmc=8452931 |pmid=34557488 |doi-access=free |number=716406}}</ref> In plants, ROS are involved in metabolic processes related to photoprotection and tolerance to various types of stress.<ref>{{Cite journal |vauthors=Grant JJ, Loake GJ |date=September 2000 |title=Role of reactive oxygen intermediates and cognate redox signaling in disease resistance |journal=Plant Physiology |volume=124 |issue=1 |pages=21–29 |doi=10.1104/pp.124.1.21 |pmc=1539275 |pmid=10982418}}</ref> However, ROS can cause irreversible damage to DNA as they oxidize and modify some cellular components and prevent them from performing their original functions. This suggests that ROS has a dual role; whether they will act as harmful, protective or signaling factors depends on the balance between ROS production and disposal at the right time and place.<ref>{{Cite journal |vauthors=Herb M, Gluschko A, Schramm M |date=September 2021 |title=Reactive Oxygen Species: Not Omnipresent but Important in Many Locations |journal=Frontiers in Cell and Developmental Biology |volume=9 |pages=716406 |doi=10.3389/fcell.2021.716406 |pmc=8452931 |pmid=34557488 |doi-access=free}}</ref><ref name="ReferenceB"/><ref name="auto">{{Cite journal |vauthors=Edreva A |date=2 April 2005 |title=Generation and scavenging of reactive oxygen species in chloroplasts: a submolecular approach |url=https://doi.org/10.1016/j.agee.2004.10.022 |journal=Agriculture, Ecosystems & Environment |language=en |volume=106 |issue=2 |pages=119–133 |bibcode=2005AgEE..106..119E |doi=10.1016/j.agee.2004.10.022 |issn=0167-8809}}</ref> In other words, oxygen toxicity can arise both from uncontrolled production and from the inefficient elimination of ROS by the antioxidant system. ROS were also demonstrated to modify the visual appearance of [[fish]].<ref name="FishInteguments">{{Cite journal |vauthors=Mouchet SR, Cortesi F, Bokic B, Lazovic V, Vukusic P, Marshall NJ, Kolaric B |date=November 2023 |title=Morphological and Optical Modification of Melanosomes in Fish Integuments upon Oxidation |journal=Optics |volume=4 |issue=4 |pages=563–562 |doi=10.3390/opt4040041 |doi-access=free}}</ref> This potentially affects their behavior and ecology, such as their temperature control, their visual communication, their reproduction and survival.
During times of environmental stress (e.g., [[ultraviolet light|UV]] or heat exposure), ROS levels can increase dramatically.<ref name="Devasagayam 2004 796" /> This may result in significant damage to cell structures. Cumulatively, this is known as [[oxidative stress]]. The production of ROS is strongly influenced by stress factor responses in plants, these factors that increase ROS production include drought, salinity, chilling, defense of pathogens, nutrient deficiency, metal toxicity and [[UV-B]] radiation. ROS are also generated by exogenous sources such as [[ionizing radiation]]<ref>{{Cite book |title=Sustaining Life on Planet Earth: Metalloenzymes Mastering Dioxygen and Other Chewy Gases |vauthors=Sosa Torres ME, Saucedo-Vázquez JP, Kroneck P |publisher=Springer |year=2015 |isbn=978-3-319-12414-8 |veditors=Kroneck PM, Torres ME |series=Metal Ions in Life Sciences |volume=15 |pages=1–12 |chapter=Chapter 1, Section 3 ''The dark side of dioxygen'' |doi=10.1007/978-3-319-12415-5_1 |pmid=25707464 |name-list-style=vanc}}</ref> generating irreversible effects in the development of tissues in both animals and plants.<ref>{{Cite journal |vauthors=Mittler R |date=January 2017 |title=ROS Are Good |journal=Trends in Plant Science |volume=22 |issue=1 |pages=11–19 |bibcode=2017TPS....22...11M |doi=10.1016/j.tplants.2016.08.002 |pmid=27666517 |doi-access=free}}</ref>