Ozone and Reactive Oxygen Species


High tropospheric ozone (O3) concentrations affect plant growth and crop yield. O3 enters leaves through stomata and rapidly degrades in the apoplast into other reactive oxygen species (ROS), which readily interact with surrounding biomolecules. Due to their high reactivity, ROS act as important signalling molecules. Apoplastic ROS perception induces secondary ROS production in other cellular compartments and activates interorganelle signalling pathways towards stress defence. Defence responses include activation of hormonal signalling, the enhancement of antioxidative defence responses, protection of the photosynthetic machinery and induction of cell death processes. Different species prioritise different defence strategies and population studies towards the identification of genetic loci associated with O3 tolerance are currently the most promising approach for identifying genes involved in O3 tolerance.

Key Concepts

  • While the stratospheric O3 layer has protective UV‐B screening properties, tropospheric O3 accumulation near the earth's surface is a health hazard to living organisms.
  • Ozone enters through open stomatal pores in the leaf epidermis and triggers rapid ROS accumulation and complex signalling pathways originating from the apoplastic space between cells.
  • Acute O3 exposure in sensitive plants results in visible cell death lesions; long‐term chronic exposures to O3 levels above 40 ppb leads to a reduction in crop yields due to reduced photosynthesis and disruption to metabolism.
  • The photosynthetic activity decreases under O3 exposure and subsequently causes a reduction in CO2 fixation and central carbohydrate metabolism. Subsequently, catabolic processes are enhanced to re‐mobilise resources, causing early senescence and a shift in source‐sink relations.
  • ROS are continuously produced during photosynthesis and respiration and ROS production increases under stress conditions. This serves as an important signalling mechanism that initiates defence and acclimation processes.
  • ROS, calcium and hormones accumulate within different intra‐ and extracellular compartments and act together as signals in a dense and complex signalling network under stress conditions.
  • Stomatal closure physically blocks the entry of air pollutants or pathogens. Stomatal closure is a defence response, triggered by O3 and other types of abiotic and biotic stress, measured through stomatal conductance (gs).
  • While harsh stress results in passive cell death, programmed cell death (PCD) is an active defence mechanism that can isolate and contain the spread of diseases to smaller areas of tissue in the plant.
  • Strategies to increase the tolerance of plants to O3 include population studies, transgenic approaches as well as the application of protective chemicals.

Keywords: reactive oxygen species (ROS); plant stress response; pollution; ozone; plant signalling

Figure 1. Global distribution of tropospheric O3. Global maps of OMI/MLS tropospheric ozone Aura O3 Monitoring Instrument (OMI) in combination with Aura Microwave Limb Sounder (MLS). Image from http://acd‐ext.gsfc.nasa.gov/Data_services/cloud_slice/gif/May16.gif. NASA tropospheric O3 concentrations, monthly average May 16th 2016. Where 40 ppb tropospheric O3 concentrations or more are associated with crop damage.
Figure 2. Ozone‐induced signaling pathways and components. Once O3 enters the apoplastic space through open stomata this is followed by a series of events. (1) O3 sensing in the apoplast and signal transduction into the cytosol via still unidentified mechanisms: (a) receptor like kinases (RLKs), (b) redox‐sensitive membrane‐bound proteins, (c) ROS transport across membranes through channels such as aquaporins, (d) membrane lipid oxidation, (2) The first biphasic ROS burst occurs in the chloroplast; (3) rapid stomatal closure defence response; (4) Second ROS burst in the apoplast via MAPK triggered phosphorylation of NADPH oxidases that generates apoplastic superoxide. (5) Downstream signalling events on PCD (HR and senescence) and acclimation via SIMR such as reduced growth and increased defence. ‘P’ surrounded by red circle indicates activation of membrane protein through phosphorylation. Purple indicates redox regulation or ROS scavenging capability. Dotted arrows indicate hypothetical pathways, solid arrows indicate connections supported by experimental evidence. ROS, reactive oxygen species; Ca2+, calcium molecules; CPK, cysteine protein kinases; NADPH oxidase, nicotinaminde adenine dinucleotide phosphate oxidase; SLAC1, slow anion channel 1; MAPK, mitogen‐activated protein kinase; O2, oxygen; O2, superoxide; H2O2, hydrogen peroxide; ABA, abscisic acid; SIMR, stress‐induced morphological response; HR, hypersensitive response; RLK, receptor‐like kinase; AsA, ascorbate; DHA, dehydroascorbate; GST, glutathione‐S‐transferase; SOD, superoxide dismutase; CAT, catalase; APX, ascorbate peroxidase; GSH, glutathione; GSSG, oxidised glutathione.


Agrawal GK, Rakwal R, Yonekura M, Kubo A and Saji H (2002) Proteome analysis of differentially displayed proteins as a tool for investigating ozone stress in rice (Oryza sativa L.) seedlings. Proteomics 2: 947–959.

Ahlfors R, Brosché M, Kollist H and Kangasjärvi J (2009) Nitric oxide modulates ozone‐induced cell death, hormone biosynthesis and gene expression in Arabidopsis thaliana. Plant Journal 58: 1–12.

Ainsworth EA, Yendrek CR, Sitch S, Collins WJ and Emberson LD (2012) The effects of tropospheric ozone on net primary productivity and implications for climate change. Annual Review of Plant Biology 63: 637–661.

Apel K and Hirt H (2004) Reactive oxygen species: metabolism, oxidative stress, and signal transduction. Annual Review of Plant Biology 55: 373–399.

Bagard M, Jolivet Y, Hasenfratz‐Sauder MP, et al. (2015) Ozone exposure and flux‐based response functions for photosynthetic traits in wheat, maize and poplar. Environmental Pollution 206: 411–420.

Biswas DK, Xu H, Li YG, et al. (2008) Genotypic differences in leaf biochemical, physiological and growth responses to ozone in 20 winter wheat cultivars released over the past 60 years. Global Change Biology 14: 46–59.

Biswas DK and Jiang GM (2011) Differential drought‐induced modulation of ozone tolerance in winter wheat species. Journal of Experimental Botany 62: 4153–4162.

Blomster T, Salojärvi J, Sipari N, et al. (2011) Apoplastic reactive oxygen species transiently decrease auxin signaling and cause stress‐induced morphogenic response in Arabidopsis. Plant Physiology 157: 1866–1883.

Brosché M, Merilo E, Mayer F, et al. (2010) Natural variation in ozone sensitivity among Arabidopsis thaliana accessions and its relation to stomatal conductance. Plant, Cell & Environment 33: 914–925.

Cheng FY, Burkey KO, Robinson JM and Booker FL (2007) Leaf extracellular ascorbate in relation to O3 tolerance of two soybean cultivars. Environmental Pollution 150: 355–362.

Cho K, Tiwari S, Agrawal SB, et al. (2011) Tropospheric ozone and plants: absorption, responses, and consequences. Reviews of Environmental Contamination and Toxicology 212: 61–111.

Chutteang C, Booker FL, Na‐Ngern P, et al. (2016) Biochemical and physiological processes associated with the differential ozone response in ozone‐tolerant and sensitive soybean genotypes. Plant Biology 18 (Suppl 1): 28–36.

Conklin PL, Williams EH and Last RL (1996) Environmental stress sensitivity of an ascorbic acid‐deficient Arabidopsis mutant. Proceedings of the National Academy of Sciences of the United States of America 93: 9970–9974.

Dghim AA, Dumont J, Hasenfratz‐Sauder MP, et al. (2013a) Capacity for NADPH regeneration in the leaves of two poplar genotypes differing in ozone sensitivity. Physiologia Plantarum 148: 36–50.

Dghim AA, Mhamdi A, Vaultier MN, et al. (2013b) Analysis of cytosolic isocitrate dehydrogenase and glutathione reductase 1 in photoperiod‐influenced responses to ozone using Arabidopsis knockout mutants. Plant, Cell & Environment 36: 1981–1991.

Dietz KJ (2003) Redox control, redox signaling, and redox homeostasis in plant cells. International Review of Cytology 228: 141–193.

Dodds PN and Rathjen JP (2010) Plant immunity: towards an integrated view of plant‐pathogen interactions. Nature Reviews Genetics 11: 539–548.

Dumont J, Keski‐Saari S, Keinänen M, et al. (2014) Ozone affects ascorbate and glutathione biosynthesis as well as amino acid contents in three Euramerican poplar genotypes. Tree Physiology 34: 253–266.

Feng Z, Pang J, Nouchi I, et al. (2010) Apoplastic ascorbate contributes to the differential ozone sensitivity in two varieties of winter wheat under fully open‐air field conditions. Environmental Pollution 158: 3539–3545.

Foyer CH and Shigeoka S (2011) Understanding oxidative stress and antioxidant functions to enhance photosynthesis. Plant Physiology 155: 93–100.

Foyer CH and Noctor G (2016) Stress‐triggered redox signalling: what's in pROSpect? Plant, Cell & Environment 39: 951–964.

Frei M, Wissuwa M, Pariasca‐Tanaka J, et al. (2012) Leaf ascorbic acid level‐‐is it really important for ozone tolerance in rice? Plant Physiology and Biochemistry 59: 63–70.

Frei M (2015) Breeding of ozone resistant rice: relevance, approaches and challenges. Environmental Pollution 197: 144–155.

Gechev TS, Van Breusegem F, Stone JM, Denev I and Laloi C (2006) Reactive oxygen species as signals that modulate plant stress responses and programmed cell death. BioEssays 28: 1091–1101.

Guidi L, Degl'Innocenti E, Giordano C, Biricolti S and Tattini M (2010) Ozone tolerance in Phaseolus vulgaris depends on more than one mechanism. Environmental Pollution 158: 3164–3171.

Hill AC and Littlefield N (1969) Ozone. Effect on apparent photosynthesis rate of transpiration and stomatal closure in plants. Environmental Science & Technology 3: 52–56.

Joo JH, Wang S, Chen JG, Jones AM and Fedoroff NV (2005) Different signaling and cell death roles of heterotrimeric G protein alpha and beta subunits in the Arabidopsis oxidative stress response to ozone. Plant Cell 17: 957–970.

Kangasjärvi S and Kangasjärvi J (2014) Towards understanding extracellular ROS sensory and signaling systems in plants. Advances in Botany 2014: 10.

Kollist H, Moldau H, Mortensen L, Rasmussen SK and Jorgensen LB (2000) Ozone flux to plasmalemma in barley and wheat is controlled by stomata rather than by direct reaction of ozone with cell wall ascorbate. Journal of Plant Physiology 156: 645–651.

Kollist T, Moldau H, Rasulov B, et al. (2007) A novel device detects a rapid ozone‐induced transient stomatal closure in intact Arabidopsis and its absence in abi2 mutant. Physiologia Plantarum 129: 796–803.

Merilo E, Laanemets K, Hu H, et al. (2013) PYR/RCAR receptors contribute to ozone‐, reduced air humidity‐, darkness‐, and CO2‐induced stomatal regulation. Plant Physiology 162: 1652–1668.

Mhamdi A, Queval G, Chaouch S, et al. (2010) Catalase function in plants: a focus on Arabidopsis mutants as stress‐mimic models. Journal of Experimental Botany 61: 4197–4220.

Munemasa S, Hauser F, Park J, et al. (2015) Mechanisms of abscisic acid‐mediated control of stomatal aperture. Current Opinion in Plant Biology 28: 154–162.

Orvar BL and Ellis BE (1997) Transgenic tobacco plants expressing antisense RNA for cytosolic ascorbate peroxidase show increased susceptibility to ozone injury. Plant Journal 11: 1297–1305.

Ou X, Gan Y, Chen P, et al. (2014) Stomata prioritize their responses to multiple biotic and abiotic signal inputs. PLoS One 9: e101587.

Overmyer K, Brosché M and Kangasjärvi J (2003) Reactive oxygen species and hormonal control of cell death. Trends in Plant Science 8: 335–342.

Pavet V, Olmos E, Kiddle G, et al. (2005) Ascorbic acid deficiency activates cell death and disease resistance responses in Arabidopsis. Plant Physiology 139: 1291–1303.

Petrov V, Hille J, Mueller‐Roeber B and Gechev TS (2015) ROS‐mediated abiotic stress‐induced programmed cell death in plants. Frontiers in Plant Science 6: 69.

Potters G, Pasternak TP, Guisez Y, Palme KJ and Jansen MA (2007) Stress‐induced morphogenic responses: growing out of trouble? Trends in Plant Science 12: 98–105.

Rao MV and Davis KR (1999) Ozone‐induced cell death occurs via two distinct mechanisms in Arabidopsis: the role of salicylic acid. Plant Journal 17: 603–614.

Ryan A, Cojocariu C, Possell M, Davies WJ and Hewitt CN (2009) Defining hybrid poplar (Populus deltoides x Populus trichocarpa) tolerance to ozone: identifying key parameters. Plant, Cell & Environment 32: 31–45.

Sarkar A, Rakwal R, Bhushan Agrawal S, et al. (2010) Investigating the impact of elevated levels of ozone on tropical wheat using integrated phenotypical, physiological, biochemical, and proteomics approaches. Journal of Proteome Research 9: 4565–4584.

Short EF, North KA, Roberts MR, et al. (2012) A stress‐specific calcium signature regulating an ozone‐responsive gene expression network in Arabidopsis. Plant Journal 71: 948–961.

Siefermann‐Harms D, Payer HD, Schramel P and Lutz C (2005) The effect of ozone on the yellowing process of magnesium‐deficient clonal Norway spruce grown under defined conditions. Journal of Plant Physiology 162: 195–206.

Sierla M, Waszczak C, Vahisalu T and Kangasjärvi J (2016) Reactive oxygen species in the regulation of stomatal movements. Plant Physiology 171: 1569–1580.

Street NR, Tallis MJ, Tucker J, et al. (2011) The physiological, transcriptional and genetic responses of an ozone‐sensitive and an ozone tolerant poplar and selected extremes of their F2 progeny. Environmental Pollution 159: 45–54.

Vahisalu T, Kollist H, Wang YF, et al. (2008) SLAC1 is required for plant guard cell S‐type anion channel function in stomatal signalling. Nature 452: 487–491.

Vahisalu T, Puzorjova I, Brosché M, et al. (2010) Ozone‐triggered rapid stomatal response involves the production of reactive oxygen species, and is controlled by SLAC1 and OST1. Plant Journal 62: 442–453.

Vainonen JP and Kangasjärvi J (2015) Plant signalling in acute ozone exposure. Plant, Cell & Environment 38: 240–252.

Wang J, Zeng Q, Zhu J, et al. (2014) Apoplastic antioxidant enzyme responses to chronic free‐air ozone exposure in two different ozone‐sensitive wheat cultivars. Plant Physiology and Biochemistry 82: 183–193.

Wilkinson S and Davies WJ (2010) Drought, ozone, ABA and ethylene: new insights from cell to plant to community. Plant, Cell & Environment 33: 510–525.

Wittig VE, Ainsworth EA and Long SP (2007) To what extent do current and projected increases in surface ozone affect photosynthesis and stomatal conductance of trees? A meta‐analytic review of the last 3 decades of experiments. Plant, Cell & Environment 30: 1150–1162.

Wrzaczek M, Brosché M, Salojärvi J, et al. (2010) Transcriptional regulation of the CRK/DUF26 group of receptor‐like protein kinases by ozone and plant hormones in Arabidopsis. BMC Plant Biology 10: 95.

Xu E, Vaahtera L, Horak H, et al. (2015) Quantitative trait loci mapping and transcriptome analysis reveal candidate genes regulating the response to ozone in Arabidopsis thaliana. Plant, Cell & Environment 38: 1418–1433.

Yalpani N, Enyedi AJ, Leon J and Raskin I (1994) Ultraviolet‐light and ozone stimulate accumulation of salicylic‐acid, pathogenesis‐related proteins and virus‐resistance in Tobacco. Planta 193: 372–376.

Yamaji K, Ohara T, Uno I, et al. (2008) Future prediction of surface ozone over east Asia using models‐3 community multiscale air quality modeling system and regional emission inventory in Asia. Journal of Geophysical Research 113 (D8): D08306.

Yoshida S, Tamaoki M, Shikano T, et al. (2006) Cytosolic dehydroascorbate reductase is important for ozone tolerance in Arabidopsis thaliana. Plant Cell Physiology 47: 304–308.

Yoshida S, Tamaoki M, Ioki M, et al. (2009) Ethylene and salicylic acid control glutathione biosynthesis in ozone‐exposed Arabidopsis thaliana. Physiologia Plantarum 136: 284–298.

Zheng YH, Li X, Li YG, et al. (2012) Contrasting responses of salinity‐stressed salt‐tolerant and intolerant winter wheat (Triticum aestivum L.) cultivars to ozone pollution. Plant Physiology and Biochemistry 52: 169–178.

Further Reading

Ainsworth EA (2016) Understanding and improving global crop response to ozone pollution. Plant Journal. DOI: 10.1111/tpj.13298.

Dentener F, Kinne S, Bond T, et al. (2006) Emissions of primary aerosol and precursor gases in the years 2000 and 1750 prescribed data‐sets for AeroCom. Atmospheric Chemistry and Physics 6: 4321–4344.

Dizengremel P, Vaultier MN, Le Thiec D, et al. (2012) Phosphoenolpyruvate is at the crossroads of leaf metabolic responses to ozone stress. New Phytologist 195: 512–517.

Donahue NM, Drozd GT, Epstein SA, Presto AA and Kroll JH (2011) Adventures in ozoneland: down the rabbit‐hole. Physical Chemistry Chemical Physics: PCCP 13: 10848–10857.

Kollist H, Nuhkat M and Roelfsema MRG (2014) Closing gaps: linking elements that control stomatal movement. New Phytologist 203: 44–62.

Lim PO, Kim HJ and Nam HG (2007) Leaf senescence. Annual Review of Plant Biology 58: 115–136.

Song Y, Miao Y and Song CP (2014) Behind the scenes: the roles of reactive oxygen species in guard cells. New Phytologist 201: 1121–1140.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Krasensky, Julia, Carmody, Melanie, Sierla, Maija, and Kangasjärvi, Jaakko(Mar 2017) Ozone and Reactive Oxygen Species. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0001299.pub3]