Register      Login
Functional Plant Biology Functional Plant Biology Society
Plant function and evolutionary biology
RESEARCH ARTICLE

In vivo and in vitro approaches demonstrate proline is not directly involved in the protection against superoxide, nitric oxide, nitrogen dioxide and peroxynitrite

Santiago Signorelli A B D , Camila Imparatta A , Marta Rodríguez-Ruiz C , Omar Borsani A , Francisco J. Corpas C and Jorge Monza A
+ Author Affiliations
- Author Affiliations

A Laboratorio de Bioquímica, Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Av. Gral. E. Garzón 809, Montevideo 12900, Uruguay.

B School of Plant Biology and the UWA Institute of Agriculture, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia.

C Group of Antioxidants, Free Radicals and Nitric Oxide in Biotechnology, Food and Agriculture, Department of Biochemistry, Cell and Molecular Biology of Plants, Estación Experimental del Zaidín, CSIC, Prof. Albareda, 1, 18008-Granada, Spain.

D Corresponding author. Email: santiago.signorellipoppolo@uwa.edu.au

Functional Plant Biology 43(9) 870-879 https://doi.org/10.1071/FP16060
Submitted: 13 November 2015  Accepted: 15 May 2016   Published: 14 June 2016

Abstract

Plants accumulate proline under diverse types of stresses, and it has been suggested that this α-amino acid has the capacity to protect against oxidative stress. However, it is still controversial whether its protection is due to the direct scavenging of reactive oxygen species (ROS). To solve this issue and considering that nitrosative stress is directly related with an oxidative stress condition, we evaluated whether proline can protect against nitrosative damage. Using proteins of Lotus japonicus (Regel) K.Larsen leaves exposed to a peroxynitrite (ONOO/ONOOH) generator in presence and absence of 100 mM proline, the potential of proline to protect was analysed by the protein nitration profile and NADP-dependent isocitrate dehydrogenase activity, which is inhibited by nitration. In both cases, the presence of proline did not diminish the peroxynitrite effects. Additionally, proline biosynthesis Arabidopsis knockout (KO) mutant plants of Δ(1)-pyrroline-5-carboxylate synthetase1 (P5CS1) gene, designated as Atp5cs1-1 and Atp5cs1-4, showed similar protein nitration levels as wild-type plants under salinity-induced oxidative stress, despite mutants having higher levels of lipid oxidation, H2O2 and superoxide (O2·). Finally, by a fluorometric assay using specific fluorescent probes, it was determined that the presence of 100 mM proline did not affect the time-course content of peroxynitrite or nitric oxide generation in vitro. Our results reveal the relevance of proline accumulation in vivo under stress, but unequivocally demonstrate that proline is not a direct scavenger of peroxynitrite, superoxide, ·NO and nitrogen dioxide (·NO2).

Additional keywords: antioxidants, plant stress, p5cs1, RNS, ROS, scavenger.


References

Airaki M, Leterrier M, Mateos RM, Valderrama R, Chaki M, Barroso JB, Del Rio LA, Palma JM, Corpas FJ (2012) Metabolism of reactive oxygen species and reactive nitrogen species in pepper (Capsicum annuum L.) plants under low temperature stress. Plant, Cell & Environment 35, 281–295.
Metabolism of reactive oxygen species and reactive nitrogen species in pepper (Capsicum annuum L.) plants under low temperature stress.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XjtVKnsLk%3D&md5=9638f44b5944131f3a464fdf3f94ec35CAS |

Alamillo JM, García-Olmedo F (2001) Effects of urate, a natural inhibitor of peroxynitrite-mediated toxicity, in the response of Arabidopsis thaliana to the bacterial pathogen Pseudomonas syringae. The Plant Journal 25, 529–540.
Effects of urate, a natural inhibitor of peroxynitrite-mediated toxicity, in the response of Arabidopsis thaliana to the bacterial pathogen Pseudomonas syringae.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXjslChtrc%3D&md5=b1ab2beaa53246bd64e5baf1f5998808CAS | 11309143PubMed |

Alia , Mohanty P, Matysik J (2001) Effect of proline on the production of singlet oxygen. Amino Acids 21, 195–200.
Effect of proline on the production of singlet oxygen.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXotFKjsLo%3D&md5=86592f59f4668ef2d8a294819bfe7110CAS | 11665815PubMed |

Alvarez B, Radi R (2003) Peroxynitrite reactivity with amino acids and proteins. Amino Acids 25, 295–311.
Peroxynitrite reactivity with amino acids and proteins.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXpsFOntb4%3D&md5=6ed9869b5bc7116b23a623eb196122c4CAS | 14661092PubMed |

Bandurska H, Niedziela J, Chadzinikolau T (2013) Separate and combined responses to water deficit and UV-B radiation. Plant Science 213, 98–105.
Separate and combined responses to water deficit and UV-B radiation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhs1KisbjK&md5=02ac6eb839575954ab509a9429591036CAS | 24157212PubMed |

Beckman JS, Beckman TW, Chen J, Marshall PA, Freeman BA (1990) Apparent hydroxyl radical production by peroxynitrite: implications for endothelial injury from nitric oxide and superoxide. Proceedings of the National Academy of Sciences of the United States of America 87, 1620–1624.
Apparent hydroxyl radical production by peroxynitrite: implications for endothelial injury from nitric oxide and superoxide.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3cXhvFegsb4%3D&md5=22f184ddc6a2a3cc0cd2adacdf1a523fCAS | 2154753PubMed |

Begara-Morales JC, Chaki M, Sanchez-Calvo B, Mata-Perez C, Leterrier M, Palma JM, Barroso JB, Corpas FJ (2013) Protein tyrosine nitration in pea roots during development and senescence. Journal of Experimental Botany 64, 1121–1134.
Protein tyrosine nitration in pea roots during development and senescence.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXjtlGrsLY%3D&md5=06ef85067b47b36b58061ed8b7417a56CAS | 23362300PubMed |

Begara-Morales JC, Sanchez-Calvo B, Chaki M, Mata-Perez C, Valderrama R, Padilla MN, Lopez-Jaramillo J, Luque F, Corpas FJ, Barroso JB (2015) Differential molecular response of monodehydroascorbate reductase and glutathione reductase by nitration and S-nitrosylation. Journal of Experimental Botany 66, 5983–5996.
Differential molecular response of monodehydroascorbate reductase and glutathione reductase by nitration and S-nitrosylation.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXitVGju7rM&md5=f5a5c009db8326dc2445bc2532af3a9aCAS | 26116026PubMed |

Ben Rejeb K, Abdelly C, Savouré A (2014) How reactive oxygen species and proline face stress together. Plant Physiology and Biochemistry 80, 278–284.
How reactive oxygen species and proline face stress together.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXpsl2mt70%3D&md5=4de5ebfb653946936f8b1b99d6efaf19CAS | 24813727PubMed |

Büssis D, Heineke D (1998) Acclimation of potato plants to polyethylene glycol-induced water deficit. II. Contents and subcellular distribution of organic solutes. Journal of Experimental Botany 49, 1361–1370.
Acclimation of potato plants to polyethylene glycol-induced water deficit. II. Contents and subcellular distribution of organic solutes.Crossref | GoogleScholarGoogle Scholar |

Carballal S, Bartesaghi S, Radi R (2014) Kinetic and mechanistic considerations to assess the biological fate of peroxynitrite. Biochimica et Biophysica Acta 1840, 768–780.
Kinetic and mechanistic considerations to assess the biological fate of peroxynitrite.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhtlCnsLjI&md5=10bd47c39ec0ae912e5d44b9fc4ccdb2CAS | 23872352PubMed |

Chaki M, Valderrama R, Fernandez-Ocana AM, Carreras A, Gomez-Rodriguez MV, Lopez-Jaramillo J, Begara-Morales JC, Sanchez-Calvo B, Luque F, Leterrier M, Corpas FJ, Barroso JB (2011) High temperature triggers the metabolism of S-nitrosothiols in sunflower mediating a process of nitrosative stress which provokes the inhibition of ferredoxin-NADP reductase by tyrosine nitration. Plant, Cell & Environment 34, 1803–1818.
High temperature triggers the metabolism of S-nitrosothiols in sunflower mediating a process of nitrosative stress which provokes the inhibition of ferredoxin-NADP reductase by tyrosine nitration.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhsVyls77M&md5=f02b9c680c68ce2695e956af0ea4ae33CAS |

Chaki M, Alvarez de Morales P, Ruiz C, Begara-Morales JC, Barroso JB, Corpas FJ, Palma JM (2015) Ripening of pepper (Capsicum annuum) fruit is characterized by an enhancement of protein tyrosine nitration. Annals of Botany 116, 637–647.
Ripening of pepper (Capsicum annuum) fruit is characterized by an enhancement of protein tyrosine nitration.Crossref | GoogleScholarGoogle Scholar | 25814060PubMed |

Chen C, Dickman MB (2005) Proline suppresses apoptosis in the fungal pathogen Colletotrichum trifolii. Proceedings of the National Academy of Sciences of the United States of America 102, 3459–3464.
Proline suppresses apoptosis in the fungal pathogen Colletotrichum trifolii.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXitl2lu7Y%3D&md5=07125c30b98b58052e646a70b601f925CAS | 15699356PubMed |

Considine MJ, María Sandalio L, Helen Foyer C (2015) Unravelling how plants benefit from ROS and NO reactions, while resisting oxidative stress. Annals of Botany 116, 469–473.
Unravelling how plants benefit from ROS and NO reactions, while resisting oxidative stress.Crossref | GoogleScholarGoogle Scholar | 26649372PubMed |

Corpas FJ, Barroso JB (2013) Nitro-oxidative stress vs oxidative or nitrosative stress in higher plants. New Phytologist 199, 633–635.
Nitro-oxidative stress vs oxidative or nitrosative stress in higher plants.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhtFSrurfJ&md5=071b6269e5af1c1c31ae05205a0be6f3CAS | 23763656PubMed |

Corpas FJ, Hayashi M, Mano S, Nishimura M, Barroso JB (2009) Peroxisomes are required for in vivo nitric oxide accumulation in the cytosol following salinity stress of Arabidopsis plants. Plant Physiology 151, 2083–2094.
Peroxisomes are required for in vivo nitric oxide accumulation in the cytosol following salinity stress of Arabidopsis plants.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhsFOgtrjP&md5=fe721204d4f15b5241f745a1455903f1CAS | 19783645PubMed |

Daiber A, Oelze M, August M, Wendt M, Sydow K, Wieboldt H, Kleschyov AL, Munzel T (2004) Detection of superoxide and peroxynitrite in model systems and mitochondria by the luminol analogue L-012. Free Radical Research 38, 259–269.
Detection of superoxide and peroxynitrite in model systems and mitochondria by the luminol analogue L-012.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXhslOkt78%3D&md5=5d060d2e34b4b37ff40a124d2058e795CAS | 15129734PubMed |

Davies MJ (2005) The oxidative environment and protein damage. Biochimica et Biophysica Acta 1703, 93–109.
The oxidative environment and protein damage.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXmvFyjsw%3D%3D&md5=0be3c084ae60ba2c9a62fd41e1425c9aCAS | 15680218PubMed |

Denicola A, Freeman BA, Trujillo M, Radi R (1996) Peroxynitrite reaction with carbon dioxide/bicarbonate: kinetics and influence on peroxynitrite-mediated oxidations. Archives of Biochemistry and Biophysics 333, 49–58.
Peroxynitrite reaction with carbon dioxide/bicarbonate: kinetics and influence on peroxynitrite-mediated oxidations.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XltleisL4%3D&md5=1ea9c8c64b827a9dac8cac610d34072eCAS | 8806753PubMed |

Desikan R, A-H-Mackerness S, Hancock JT, Neill SJ (2001) Regulation of the Arabidopsis transcriptome by oxidative stress. Plant Physiology 127, 159–172.
Regulation of the Arabidopsis transcriptome by oxidative stress.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXmvFCrt7g%3D&md5=5c74173af4a191697180f1884925de1bCAS | 11553744PubMed |

Dinakar N, Nagajyothi PC, Suresh S, Damodharam T, Suresh C (2009) Cadmium induced changes on proline, antioxidant enzymes, nitrate and nitrite reductases in Arachis hypogaea L. Journal of environmental biology / Academy of Environmental Biology, India 30, 289–294.

Erdal S (2012) Androsterone-induced molecular and physiological changes in maize seedlings in response to chilling stress. Plant Physiology and Biochemistry 57, 1–7.
Androsterone-induced molecular and physiological changes in maize seedlings in response to chilling stress.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhtFaitL3I&md5=05b8669b737d45370b988f69f1b6d261CAS | 22634365PubMed |

Ferrer-Sueta G, Radi R (2009) Chemical biology of peroxynitrite: kinetics, diffusion, and radicals. ACS Chemical Biology 4, 161–177.
Chemical biology of peroxynitrite: kinetics, diffusion, and radicals.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXislOisbg%3D&md5=00ec5e9ba2cc63c41cc3e988cf65e352CAS | 19267456PubMed |

Foreman J, Demidchik V, Bothwell JHF, Mylona P, Miedema H, Torres MA, Linstead P, Costa S, Brownlee C, Jones JDG, Davies JM, Dolan L (2003) Reactive oxygen species produced by NADPH oxidase regulate plant cell growth. Nature 422, 442–446.
Reactive oxygen species produced by NADPH oxidase regulate plant cell growth.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXitlGgtLg%3D&md5=a7a4f2bcfd8ee509314e33a5040de58eCAS | 12660786PubMed |

Fukai E, Soyano T, Umehara Y, Nakayama S, Hirakawa H, Tabata S, Sato S, Hayashi M (2012) Establishment of a Lotus japonicus gene tagging population using the exon-targeting endogenous retrotransposon LORE1. The Plant Journal 69, 720–730.
Establishment of a Lotus japonicus gene tagging population using the exon-targeting endogenous retrotransposon LORE1.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xjt12gt7o%3D&md5=e7b1183ec12ce941644d4b129327b515CAS | 22014259PubMed |

Gaupels F, Spiazzi-Vandelle E, Yang D, Delledonne M (2011) Detection of peroxynitrite accumulation in Arabidopsis thaliana during the hypersensitive defense response. Nitric Oxide 25, 222–228.
Detection of peroxynitrite accumulation in Arabidopsis thaliana during the hypersensitive defense response.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXpvFCmt7Y%3D&md5=7bd74fa9eff0e8d7f0efa37b00444371CAS | 21296177PubMed |

Goldstein S, Czapski G (1995) The reaction of NO· with O2 · – and HO2 ·: a pulse radiolysis study. Free Radical Biology & Medicine 19, 505–510.
The reaction of NO· with O2 · and HO2 ·: a pulse radiolysis study.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXnsVynurk%3D&md5=a19dbc23ce90276a8840f743748b531cCAS |

Hare PD, Cress WA, Van Staden J (1998) Dissecting the roles of osmolyte accumulation during stress. Plant, Cell & Environment 21, 535–553.
Dissecting the roles of osmolyte accumulation during stress.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXltl2hu7s%3D&md5=245f3a011877c12f1e770d98ba009dbeCAS |

Hichri I, Boscari A, Castella C, Rovere M, Puppo A, Brouquisse R (2015) Nitric oxide: a multifaceted regulator of the nitrogen-fixing symbiosis. Journal of Experimental Botany 66, 2877–2887.
Nitric oxide: a multifaceted regulator of the nitrogen-fixing symbiosis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXitVWhtL%2FN&md5=bcc27c0e2748e72656facbfcd0b10717CAS | 25732535PubMed |

Holzmeister C, Gaupels F, Geerlof A, Sarioglu H, Sattler M, Durner J, Lindermayr C (2015) Differential inhibition of Arabidopsis superoxide dismutases by peroxynitrite-mediated tyrosine nitration. Journal of Experimental Botany 66, 989–999.
Differential inhibition of Arabidopsis superoxide dismutases by peroxynitrite-mediated tyrosine nitration.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXitVamtLvP&md5=9d3bcd25ad159fb929af0007b9b7a0c3CAS | 25428993PubMed |

Huang C, Wei G, Jie Y, Wang L, Zhou H, Ran C, Huang Z, Jia H, Anjum SA (2014) Effects of concentrations of sodium chloride on photosynthesis, antioxidative enzymes, growth and fiber yield of hybrid ramie. Plant Physiology and Biochemistry 76, 86–93.
Effects of concentrations of sodium chloride on photosynthesis, antioxidative enzymes, growth and fiber yield of hybrid ramie.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXitlCitL8%3D&md5=2aaf26dda6d08164d3f8f047aa78cda4CAS | 24486583PubMed |

Jabs T, Dietrich RA, Dangl JL (1996) Initiation of runaway cell death in an Arabidopsis mutant by extracellular superoxide. Science 273, 1853–1856.
Initiation of runaway cell death in an Arabidopsis mutant by extracellular superoxide.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XlvFCrsLk%3D&md5=2ee22a481d0da532f89c429d12078e60CAS | 8791589PubMed |

Kavi Kishor PB, Sreenivasulu N (2014) Is proline accumulation per se correlated with stress tolerance or is proline homeostasis a more critical issue? Plant, Cell & Environment 37, 300–311.
Is proline accumulation per se correlated with stress tolerance or is proline homeostasis a more critical issue?Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXlsF2itQ%3D%3D&md5=01773bd283a411a09bd1df6696983d48CAS |

Khavari-Nejad RA, Shekaste Band R, Najafi F, Nabiuni M, Gharari Z (2013) The role of Pro-P5C cycle in chs mutants of Arabidopsis under cold stress 1. Russian Journal of Plant Physiology: a Comprehensive Russian Journal on Modern Phytophysiology 60, 375–382.
The role of Pro-P5C cycle in chs mutants of Arabidopsis under cold stress 1.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXmtlCgsrs%3D&md5=5a10a33c67916cff47a39f16bf15e42fCAS |

Kishor PBK, Kumari PH, Sunita MSL, Sreenivasulu N (2015) Role of proline in cell wall synthesis and plant development and its implications in plant ontogeny. Frontiers in Plant Science 6, 1–17.

Laemmli UK (1970) Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227, 680–685.
Cleavage of structural proteins during the assembly of the head of bacteriophage T4.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXlsFags7s%3D&md5=f771fc7db2ab91c72fd2b429b6d4095aCAS | 5432063PubMed |

Mattioli R, Marchese D, D’Angeli S, Altamura MM, Costantino P, Trovato M (2008) Modulation of intracellular proline levels affects flowering time and inflorescence architecture in Arabidopsis. Plant Molecular Biology 66, 277–288.
Modulation of intracellular proline levels affects flowering time and inflorescence architecture in Arabidopsis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhsVKnsr3N&md5=74dcb1116dc44adedc74453d1ee9e6aeCAS | 18060533PubMed |

Mattioli R, Costantino P, Trovato M (2009) Proline accumulation in plants: not only stress. Plant Signaling & Behavior 4, 1016–1018.
Proline accumulation in plants: not only stress.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXms1aisr4%3D&md5=1928204f165ca6e1d59cf350fb7ff2faCAS |

Murashige T, Skoog F (1962) A revised medium for rapid growth and bio-assays with tobacco tissue cultures. Physiologia Plantarum 15, 473–497.
A revised medium for rapid growth and bio-assays with tobacco tissue cultures.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF3sXksFKm&md5=3e14ca2e1300bcfb216c06e8c97b09daCAS |

Nakatsubo N, Kojima H, Kikuchi K, Nagoshi H, Hirata Y, Maeda D, Imai Y, Irimura T, Nagano T (1998) Direct evidence of nitric oxide production from bovine aortic endothelial cells using new fluorescence indicators: diaminofluoresceins. FEBS Letters 427, 263–266.
Direct evidence of nitric oxide production from bovine aortic endothelial cells using new fluorescence indicators: diaminofluoresceins.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXjtVKju7Y%3D&md5=756706dc337598af450681d22ddea447CAS | 9607324PubMed |

Radi R (2013) Protein tyrosine nitration: biochemical mechanisms and structural basis of functional effects. Accounts of Chemical Research 46, 550–559.
Protein tyrosine nitration: biochemical mechanisms and structural basis of functional effects.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xhs12mtrvL&md5=4b1ffaec15b9018a92a1551c86e9d8aeCAS | 23157446PubMed |

Semida WM, Rady MM (2014) Presoaking application of propolis and maize grain extracts alleviates salinity stress in common bean (Phaseolus vulgaris L.). Scientia Horticulturae 168, 210–217.
Presoaking application of propolis and maize grain extracts alleviates salinity stress in common bean (Phaseolus vulgaris L.).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2cXltFCnurw%3D&md5=f9646aa458cc7173652a2efbfd5569c1CAS |

Sharma S, Villamor JG, Versules PE (2011) Essential role of tissue-specific proline synthesis and catabolism in growth and redox balance at low water potential. Plant Physiology 157, 292–304.
Essential role of tissue-specific proline synthesis and catabolism in growth and redox balance at low water potential.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXht1Sit7zP&md5=9a99fce7cd7a0303dabd863973c03656CAS | 21791601PubMed |

Shi H, Ye T, Zhu JK, Chan Z (2014) Constitutive production of nitric oxide leads to enhanced drought stress resistance and extensive transcriptional reprogramming in Arabidopsis. Journal of Experimental Botany 65, 4119–4131.
Constitutive production of nitric oxide leads to enhanced drought stress resistance and extensive transcriptional reprogramming in Arabidopsis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC2MXitVGjsr%2FF&md5=d5c614f58f400ac6a352f55ef19e1f87CAS | 24868034PubMed |

Signorelli S, Arellano JB, Melø TB, Borsani O, Monza J (2013a) Proline does not quench singlet oxygen: evidence to reconsider its protective role in plants. Plant Physiology and Biochemistry 64, 80–83.
Proline does not quench singlet oxygen: evidence to reconsider its protective role in plants.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXislWgu70%3D&md5=38d75e9a0e93cbc777fbfc05c98764b0CAS | 23384940PubMed |

Signorelli S, Casaretto E, Sainz M, Díaz P, Monza J, Borsani O (2013b) Antioxidant and photosystem II responses contribute to explain the drought-heat contrasting tolerance of two forage legumes. Plant Physiology and Biochemistry 70, 195–203.
Antioxidant and photosystem II responses contribute to explain the drought-heat contrasting tolerance of two forage legumes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhtFOkur7N&md5=a4618fe3da50bf11ce4dbcf09c6e4df4CAS | 23792824PubMed |

Signorelli S, Corpas FJ, Borsani O, Barroso JB, Monza J (2013c) Water stress induces a differential and spatially distributed nitro-oxidative stress response in roots and leaves of Lotus japonicus. Plant Science 201–202, 137–146.
Water stress induces a differential and spatially distributed nitro-oxidative stress response in roots and leaves of Lotus japonicus.Crossref | GoogleScholarGoogle Scholar | 23352412PubMed |

Signorelli S, Coitiño EL, Borsani O, Monza J (2014) Molecular mechanisms for the reaction between ·OH radicals and proline: insights on the role as reactive oxygen species scavenger in plant stress. Journal of Physical Chemistry B 118, 37–47.
Molecular mechanisms for the reaction between ·OH radicals and proline: insights on the role as reactive oxygen species scavenger in plant stress.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhvFejsbfO&md5=898a3e12b3c8e824ff4aa5a27adb4334CAS |

Signorelli S, Dans PD, Coitiño EL, Borsani O, Monza J (2015) Connecting proline and γ-aminobutyric acid in stressed plants through non-enzymatic reactions. PLoS One 10, e0115349
Connecting proline and γ-aminobutyric acid in stressed plants through non-enzymatic reactions.Crossref | GoogleScholarGoogle Scholar | 25775459PubMed |

Simic MG, Jovanovic SV (1989) Antioxidation mechanisms of uric acid. Journal of the American Chemical Society 111, 5778–5782.
Antioxidation mechanisms of uric acid.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXkslOgsb8%3D&md5=5274dba2f1df98baddd05accdca6e7a8CAS |

Smirnoff N, Cumbes QJ (1989) Hydroxyl radical scavenging activity of compatible solutes. Phytochemistry 28, 1057–1060.
Hydroxyl radical scavenging activity of compatible solutes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL1MXktlGgu7Y%3D&md5=0154766b0dd01128bbc50dc5bfaed4cfCAS |

Szabados L, Savouré A (2010) Proline: a multifunctional amino acid. Trends in Plant Science 15, 89–97.
Proline: a multifunctional amino acid.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhs1yit7s%3D&md5=512f9924f05362a33990e97c402adf34CAS | 20036181PubMed |

Székely G, Abrahám E, Cséplo A, Rigó G, Zsigmond L, Csiszár J, Ayaydin F, Strizhov N, Jásik J, Schmelzer E, Koncz C, Szabados L (2008) Duplicated P5CS genes of Arabidopsis play distinct roles in stress regulation and developmental control of proline biosynthesis. The Plant Journal 53, 11–28.
Duplicated P5CS genes of Arabidopsis play distinct roles in stress regulation and developmental control of proline biosynthesis.Crossref | GoogleScholarGoogle Scholar | 17971042PubMed |

Tanou G, Filippou P, Belghazi M, Job D, Diamantidis G, Fotopoulos V, Molassiotis A (2012) Oxidative and nitrosative-based signaling and associated post-translational modifications orchestrate the acclimation of citrus plants to salinity stress. The Plant Journal 72, 585–599.
Oxidative and nitrosative-based signaling and associated post-translational modifications orchestrate the acclimation of citrus plants to salinity stress.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xhs1Sht7nF&md5=34229e598cbc16cd9604e4fd9a05f88eCAS | 22780834PubMed |

Taubert D, Breitenbach T, Lazar A, Censarek P, Harlfinger S, Berkels R, Klaus W, Roesen R (2003) Reaction rate constants of superoxide scavenging by plant antioxidants. Free Radical Biology & Medicine 35, 1599–1607.
Reaction rate constants of superoxide scavenging by plant antioxidants.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3sXpvVenu7w%3D&md5=e7de894a9cda6c01b6f3aa4873ff74c3CAS |

Thordal-Christensen H, Zhang Z, Wei Y, Collinge DB (1997) Subcellular localization of H2O2 in plants. H2O2 accumulation in papillae and hypersensitive response during the barley-powdery mildew interaction. The Plant Journal 11, 1187–1194.
Subcellular localization of H2O2 in plants. H2O2 accumulation in papillae and hypersensitive response during the barley-powdery mildew interaction.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXkslajtLs%3D&md5=2032e3beb75dfe4525771608005f17c8CAS |

Trovato M, Mattioli R, Costantino P (2008) Multiple roles of proline in plant stress tolerance and development. Rendiconti Lincei 19, 325–346.
Multiple roles of proline in plant stress tolerance and development.Crossref | GoogleScholarGoogle Scholar |

Wang Y, Luo Z, Du R, Liu Y, Ying T, Mao L (2013) Effect of nitric oxide on antioxidative response and proline metabolism in banana during cold storage. Journal of Agricultural and Food Chemistry 61, 8880–8887.
Effect of nitric oxide on antioxidative response and proline metabolism in banana during cold storage.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXht1ymt7vJ&md5=40ca1f349f8ea967557fd8c2baf3f8aeCAS | 23952496PubMed |

Wilson RA, Sangha MK, Banga SS, Atwal A, Gupta S (2014) Heat stress tolerance in relation to oxidative stress and antioxidants in Brassica juncea. Journal of Environmental Biology 35, 383–387.

Yamamoto Y, Kobayashi Y, Matsumoto H (2001) Lipid peroxidation is an early symptom triggered by aluminum, but not the primary cause of elongation inhibition in pea roots. Plant Physiology 125, 199–208.
Lipid peroxidation is an early symptom triggered by aluminum, but not the primary cause of elongation inhibition in pea roots.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXjslymu7o%3D&md5=82078ee1027dbf770c2652532d939bb3CAS | 11154329PubMed |

Zhang L, Becker DF (2015) Connecting proline metabolism and signaling pathways in plant senescence. Frontiers in Plant Science 6, 1–8.

Zhang L, Alfano JR, Becker DF (2015) Proline metabolism increases katG expression and oxidative stress resistance in Escherichia coli. Journal of Bacteriology 197, 431–440.
Proline metabolism increases katG expression and oxidative stress resistance in Escherichia coli.Crossref | GoogleScholarGoogle Scholar | 25384482PubMed |