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Sperdouli I, Panteris E, Moustaka J, Aydın T, Bayçu G, Moustakas M. Mechanistic Insights on Salicylic Acid-Induced Enhancement of Photosystem II Function in Basil Plants under Non-Stress or Mild Drought Stress. Int J Mol Sci 2024; 25:5728. [PMID: 38891916 PMCID: PMC11171592 DOI: 10.3390/ijms25115728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 05/08/2024] [Accepted: 05/22/2024] [Indexed: 06/21/2024] Open
Abstract
Photosystem II (PSII) functions were investigated in basil (Ocimum basilicum L.) plants sprayed with 1 mM salicylic acid (SA) under non-stress (NS) or mild drought-stress (MiDS) conditions. Under MiDS, SA-sprayed leaves retained significantly higher (+36%) chlorophyll content compared to NS, SA-sprayed leaves. PSII efficiency in SA-sprayed leaves under NS conditions, evaluated at both low light (LL, 200 μmol photons m-2 s-1) and high light (HL, 900 μmol photons m-2 s-1), increased significantly with a parallel significant decrease in the excitation pressure at PSII (1-qL) and the excess excitation energy (EXC). This enhancement of PSII efficiency under NS conditions was induced by the mechanism of non-photochemical quenching (NPQ) that reduced singlet oxygen (1O2) production, as indicated by the reduced quantum yield of non-regulated energy loss in PSII (ΦNO). Under MiDS, the thylakoid structure of water-sprayed leaves appeared slightly dilated, and the efficiency of PSII declined, compared to NS conditions. In contrast, the thylakoid structure of SA-sprayed leaves did not change under MiDS, while PSII functionality was retained, similar to NS plants at HL. This was due to the photoprotective heat dissipation by NPQ, which was sufficient to retain the same percentage of open PSII reaction centers (qp), as in NS conditions and HL. We suggest that the redox status of the plastoquinone pool (qp) under MiDS and HL initiated the acclimation response to MiDS in SA-sprayed leaves, which retained the same electron transport rate (ETR) with control plants. Foliar spray of SA could be considered as a method to improve PSII efficiency in basil plants under NS conditions, at both LL and HL, while under MiDS and HL conditions, basil plants could retain PSII efficiency similar to control plants.
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Affiliation(s)
- Ilektra Sperdouli
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organisation–Demeter (ELGO-Dimitra), 57001 Thermi, Greece;
| | - Emmanuel Panteris
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - Julietta Moustaka
- Department of Food Science, Aarhus University, 8200 Aarhus, Denmark;
| | - Tuğba Aydın
- Department of Biology, Faculty of Science, Istanbul University, 34134 Istanbul, Turkey; (T.A.); (G.B.)
| | - Gülriz Bayçu
- Department of Biology, Faculty of Science, Istanbul University, 34134 Istanbul, Turkey; (T.A.); (G.B.)
| | - Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
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Sperdouli I, Ouzounidou G, Moustakas M. Hormesis Responses of Photosystem II in Arabidopsis thaliana under Water Deficit Stress. Int J Mol Sci 2023; 24:ijms24119573. [PMID: 37298524 DOI: 10.3390/ijms24119573] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 05/26/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Since drought stress is one of the key risks for the future of agriculture, exploring the molecular mechanisms of photosynthetic responses to water deficit stress is, therefore, fundamental. By using chlorophyll fluorescence imaging analysis, we evaluated the responses of photosystem II (PSII) photochemistry in young and mature leaves of Arabidopsis thaliana Col-0 (cv Columbia-0) at the onset of water deficit stress (OnWDS) and under mild water deficit stress (MiWDS) and moderate water deficit stress (MoWDS). Moreover, we tried to illuminate the underlying mechanisms in the differential response of PSII in young and mature leaves to water deficit stress in the model plant A. thaliana. Water deficit stress induced a hormetic dose response of PSII function in both leaf types. A U-shaped biphasic response curve of the effective quantum yield of PSII photochemistry (ΦPSII) in A. thaliana young and mature leaves was observed, with an inhibition at MiWDS that was followed by an increase in ΦPSII at MoWDS. Young leaves exhibited lower oxidative stress, evaluated by malondialdehyde (MDA), and higher levels of anthocyanin content compared to mature leaves under both MiWDS (+16%) and MoWDS (+20%). The higher ΦPSII of young leaves resulted in a decreased quantum yield of non-regulated energy loss in PSII (ΦNO), under both MiWDS (-13%) and MoWDS (-19%), compared to mature leaves. Since ΦNO represents singlet-excited oxygen (1O2) generation, this decrease resulted in lower excess excitation energy at PSII, in young leaves under both MiWDS (-10%) and MoWDS (-23%), compared to mature leaves. The hormetic response of PSII function in both young and mature leaves is suggested to be triggered, under MiWDS, by the intensified reactive oxygen species (ROS) generation, which is considered to be beneficial for activating stress defense responses. This stress defense response that was induced at MiWDS triggered an acclimation response in A. thaliana young leaves and provided tolerance to PSII when water deficit stress became more severe (MoWDS). We concluded that the hormesis responses of PSII in A. thaliana under water deficit stress are regulated by the leaf developmental stage that modulates anthocyanin accumulation in a stress-dependent dose.
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Affiliation(s)
- Ilektra Sperdouli
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organization-Dimitra, GR-57001 Thessaloniki, Greece
| | - Georgia Ouzounidou
- Institute of Food Technology, Hellenic Agricultural Organization-Dimitra, GR-14123 Lycovrissi, Greece
| | - Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
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Moustakas M, Dobrikova A, Sperdouli I, Hanć A, Adamakis IDS, Moustaka J, Apostolova E. A Hormetic Spatiotemporal Photosystem II Response Mechanism of Salvia to Excess Zinc Exposure. Int J Mol Sci 2022; 23:11232. [PMID: 36232535 PMCID: PMC9569477 DOI: 10.3390/ijms231911232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 09/14/2022] [Accepted: 09/21/2022] [Indexed: 11/17/2022] Open
Abstract
Exposure of Salvia sclarea plants to excess Zn for 8 days resulted in increased Ca, Fe, Mn, and Zn concentrations, but decreased Mg, in the aboveground tissues. The significant increase in the aboveground tissues of Mn, which is vital in the oxygen-evolving complex (OEC) of photosystem II (PSII), contributed to the higher efficiency of the OEC, and together with the increased Fe, which has a fundamental role as a component of the enzymes involved in the electron transport process, resulted in an increased electron transport rate (ETR). The decreased Mg content in the aboveground tissues contributed to decreased chlorophyll content that reduced excess absorption of sunlight and operated to improve PSII photochemistry (ΦPSII), decreasing excess energy at PSII and lowering the degree of photoinhibition, as judged from the increased maximum efficiency of PSII photochemistry (Fv/Fm). The molecular mechanism by which Zn-treated leaves displayed an improved PSII photochemistry was the increased fraction of open PSII reaction centers (qp) and, mainly, the increased efficiency of the reaction centers (Fv'/Fm') that enhanced ETR. Elemental bioimaging of Zn and Ca by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) revealed their co-localization in the mid-leaf veins. The high Zn concentration was located in the mid-leaf-vein area, while mesophyll cells accumulated small amounts of Zn, thus resembling a spatiotemporal heterogenous response and suggesting an adaptive strategy. These findings contribute to our understanding of how exposure to excess Zn triggered a hormetic response of PSII photochemistry. Exposure of aromatic and medicinal plants to excess Zn in hydroponics can be regarded as an economical approach to ameliorate the deficiency of Fe and Zn, which are essential micronutrients for human health.
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Affiliation(s)
- Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Anelia Dobrikova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Ilektra Sperdouli
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organisation-Demeter (ELGO-Demeter), 57001 Thermi, Greece
| | - Anetta Hanć
- Department of Trace Analysis, Faculty of Chemistry, Adam Mickiewicz University, 61614 Poznań, Poland
| | | | - Julietta Moustaka
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Emilia Apostolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
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Terletskaya NV, Seitimova GA, Kudrina NO, Meduntseva ND, Ashimuly K. The Reactions of Photosynthetic Capacity and Plant Metabolites of Sedum hybridum L. in Response to Mild and Moderate Abiotic Stresses. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11060828. [PMID: 35336710 PMCID: PMC8955115 DOI: 10.3390/plants11060828] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 02/26/2022] [Accepted: 03/06/2022] [Indexed: 05/17/2023]
Abstract
In this article, for the first time, an experimental study of the effect of mild and moderate osmotic stress, NaCl content and the effect of low positive temperature on photosynthetic activity and composition of metabolites of immature plants Sedum hybridum L. is reported. In this representative of the genus Sedum adapted to arid conditions and having the properties of a succulent, a change in photosynthetic activity and an increase in the level of protective metabolites in the shoots were revealed when exposed to mild and moderate stress factors. The results of this study can be used in work on the adaptation of succulent plants to arid conditions, environmental monitoring and work on the directed induction of valuable secondary metabolites in succulents to obtain new herbal medicines.
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Affiliation(s)
- Nina V. Terletskaya
- Faculty of Biology and Biotechnology and Faculty of Chemistry and Chemical Technology, Al-Farabi Kazakh National University, Al-Farabi Avenue 71, Almaty 050040, Kazakhstan; (G.A.S.); (N.D.M.); (K.A.)
- Institute of Genetic and Physiology, Al-Farabi Avenue 93, Almaty 050040, Kazakhstan
- Correspondence: (N.V.T.); (N.O.K.); Tel.: +7-(777)-2993-335 (N.V.T.); +7-(705)-1811-440 (N.O.K.)
| | - Gulnaz A. Seitimova
- Faculty of Biology and Biotechnology and Faculty of Chemistry and Chemical Technology, Al-Farabi Kazakh National University, Al-Farabi Avenue 71, Almaty 050040, Kazakhstan; (G.A.S.); (N.D.M.); (K.A.)
- Institute of Genetic and Physiology, Al-Farabi Avenue 93, Almaty 050040, Kazakhstan
| | - Nataliya O. Kudrina
- Faculty of Biology and Biotechnology and Faculty of Chemistry and Chemical Technology, Al-Farabi Kazakh National University, Al-Farabi Avenue 71, Almaty 050040, Kazakhstan; (G.A.S.); (N.D.M.); (K.A.)
- Institute of Genetic and Physiology, Al-Farabi Avenue 93, Almaty 050040, Kazakhstan
- Correspondence: (N.V.T.); (N.O.K.); Tel.: +7-(777)-2993-335 (N.V.T.); +7-(705)-1811-440 (N.O.K.)
| | - Nataliya D. Meduntseva
- Faculty of Biology and Biotechnology and Faculty of Chemistry and Chemical Technology, Al-Farabi Kazakh National University, Al-Farabi Avenue 71, Almaty 050040, Kazakhstan; (G.A.S.); (N.D.M.); (K.A.)
| | - Kazhybek Ashimuly
- Faculty of Biology and Biotechnology and Faculty of Chemistry and Chemical Technology, Al-Farabi Kazakh National University, Al-Farabi Avenue 71, Almaty 050040, Kazakhstan; (G.A.S.); (N.D.M.); (K.A.)
- Institute of Genetic and Physiology, Al-Farabi Avenue 93, Almaty 050040, Kazakhstan
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Root-Associated Entomopathogenic Fungi Modulate Their Host Plant's Photosystem II Photochemistry and Response to Herbivorous Insects. MOLECULES (BASEL, SWITZERLAND) 2021; 27:molecules27010207. [PMID: 35011439 PMCID: PMC8746981 DOI: 10.3390/molecules27010207] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/23/2021] [Accepted: 12/26/2021] [Indexed: 02/07/2023]
Abstract
The escalating food demand and loss to herbivores has led to increasing interest in using resistance-inducing microbes for pest control. Here, we evaluated whether root-inoculation with fungi that are otherwise known as entomopathogens improves tomato (Solanum lycopersicum) leaflets' reaction to herbivory by Spodoptera exigua (beet armyworm) larvae using chlorophyll fluorescence imaging. Plants were inoculated with Metarhizium brunneum or Beauveria bassiana, and photosystem II reactions were evaluated before and after larval feeding. Before herbivory, the fraction of absorbed light energy used for photochemistry (ΦPSII) was lower in M. brunneum-inoculated than in control plants, but not in B. bassiana-inoculated plants. After herbivory, however, ΦPSII increased in the fungal-inoculated plants compared with that before herbivory, similar to the reaction of control plants. At the same time, the fraction of energy dissipated as heat (ΦNPQ) decreased in the inoculated plants, resulting in an increased fraction of nonregulated energy loss (ΦNO) in M. brunneum. This indicates an increased singlet oxygen (1O2) formation not detected in B. bassiana-inoculated plants, showing that the two entomopathogenic fungi differentially modulate the leaflets' response to herbivory. Overall, our results show that M. brunneum inoculation had a negative effect on the photosynthetic efficiency before herbivory, while B. bassiana inoculation had no significant effect. However, S. exigua leaf biting activated the same compensatory PSII response mechanism in tomato plants of both fungal-inoculated treatments as in control plants.
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Harnessing Chlorophyll Fluorescence for Phenotyping Analysis of Wild and Cultivated Tomato for High Photochemical Efficiency under Water Deficit for Climate Change Resilience. CLIMATE 2021. [DOI: 10.3390/cli9110154] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Fluctuations of the weather conditions, due to global climate change, greatly influence plant growth and development, eventually affecting crop yield and quality, but also plant survival. Since water shortage is one of the key risks for the future of agriculture, exploring the capability of crop species to grow with limited water is therefore fundamental. By using chlorophyll fluorescence analysis, we evaluated the responses of wild tomato accession Solanum pennellii LA0716, Solanum lycopersicum cv. Μ82, the introgression line IL12-4 (from cv. M82 Χ LA0716), and the Greek tomato cultivars cv. Santorini and cv. Zakinthos, to moderate drought stress (MoDS) and severe drought stress (SDS), in order to identify the minimum irrigation level for efficient photosynthetic performance. Agronomic traits (plant height, number of leaves and root/shoot biomass), relative water content (RWC), and lipid peroxidation, were also measured. Under almost 50% deficit irrigation, S. pennellii exhibited an enhanced photosynthetic function by displaying a hormetic response of electron transport rate (ETR), due to an increased fraction of open reaction centers, it is suggested to be activated by the low increase of reactive oxygen species (ROS). A low increase of ROS is regarded to be beneficial by stimulating defense responses and also triggering a more oxidized redox state of quinone A (QA), corresponding in S. pennellii under 50% deficit irrigation, to the lowest stomatal opening, resulting in reduction of water loss. Solanumpennellii was the most tolerant to drought, as it was expected, and could manage to have an adequate photochemical function with almost 30% water regime of well-watered plants. With 50% deficit irrigation, cv. Μ82 and cv. Santorini did not show any difference in photochemical efficiency to control plants and are recommended to be cultivated under deficit irrigation as an effective strategy to enhance agricultural sustainability under a global climate change. We conclude that instead of the previously used Fv/Fm ratio, the redox state of QA, as it can be estimated by the chlorophyll fluorescence parameter 1 - qL, is a better indicator to evaluate photosynthetic efficiency and select drought tolerant cultivars under deficit irrigation.
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Calabrese EJ, Agathokleous E, Calabrese V. Ferulic acid and hormesis: Biomedical and environmental implications. Mech Ageing Dev 2021; 198:111544. [PMID: 34274398 DOI: 10.1016/j.mad.2021.111544] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/09/2021] [Accepted: 07/13/2021] [Indexed: 01/14/2023]
Abstract
The present paper provides the first systematic assessment of the capacity of ferulic acid to induce hormetic dose responses in biological systems. Ferulic acid induced hormetic effects in a broad range of animal models, affecting numerous biological endpoints, with particular focus on neuroprotective effects. Emerging evidence in multiple biomedical systems indicates that the hormetic effects of ferulic acid depend upon the activation of the transcription factor Nrf2. Ferulic acid was also shown to have an important role in ecological settings, being routinely released into the environment by numerous plant species, acting as an allelopathic agent affecting the growth of neighboring species via hormetic dose responses. These findings demonstrate the potential ecological and biomedical importance of ferulic acid effects and that these effects are commonly expressed via the hormetic dose response, suggesting complex multisystem evolutionary regulatory strategies.
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Affiliation(s)
- Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA.
| | - Evgenios Agathokleous
- Key Laboratory of Agrometeorology of Jiangsu Province, Department of Ecology, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, 210044, China.
| | - Vittorio Calabrese
- Department of Biomedical and Biotechnological Sciences, School of Medicine University of Catania, Via Santa Sofia 97, Catania, 95123, Italy.
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Leaf Age-Dependent Photosystem II Photochemistry and Oxidative Stress Responses to Drought Stress in Arabidopsis thaliana Are Modulated by Flavonoid Accumulation. Molecules 2021; 26:molecules26144157. [PMID: 34299433 PMCID: PMC8307756 DOI: 10.3390/molecules26144157] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/04/2021] [Accepted: 07/06/2021] [Indexed: 11/17/2022] Open
Abstract
We investigated flavonoid accumulation and lipid peroxidation in young leaves (YL) and mature leaves (ML) of Arabidopsis thaliana plants, whose watering stopped 24 h before sampling, characterized as onset of drought stress (OnDS), six days before sampling, characterized as mild drought stress (MiDS), and ten days before sampling, characterized as moderate drought stress (MoDS). The response to drought stress (DS) of photosystem II (PSII) photochemistry, in both leaf types, was evaluated by estimating the allocation of absorbed light to photochemistry (ΦPSII), to heat dissipation by regulated non-photochemical energy loss (ΦNPQ) and to non-regulated energy dissipated in PSII (ΦNO). Young leaves were better protected at MoDS than ML leaves, by having higher concentration of flavonoids that promote acclimation of YL PSII photochemistry to MoDS, showing lower lipid peroxidation and excitation pressure (1 - qp). Young leaves at MoDS possessed lower 1 - qp values and lower excess excitation energy (EXC), not only compared to MoDS ML, but even to MiDS YL. They also possessed a higher capacity to maintain low ΦNO, suggesting a lower singlet oxygen (1O2) generation. Our results highlight that leaves of different developmental stage may display different responses to DS, due to differential accumulation of metabolites, and imply that PSII photochemistry in Arabidopsis thaliana may not show a dose dependent DS response.
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Changes in Light Energy Utilization in Photosystem II and Reactive Oxygen Species Generation in Potato Leaves by the Pinworm Tuta absoluta. Molecules 2021; 26:molecules26102984. [PMID: 34069787 PMCID: PMC8157303 DOI: 10.3390/molecules26102984] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/11/2021] [Accepted: 05/14/2021] [Indexed: 12/28/2022] Open
Abstract
We evaluated photosystem II (PSII) functionality in potato plants (Solanum tuberosum L.) before and after a 15 min feeding by the leaf miner Tuta absoluta using chlorophyll a fluorescence imaging analysis combined with reactive oxygen species (ROS) detection. Fifteen minutes after feeding, we observed at the feeding zone and at the whole leaf a decrease in the effective quantum yield of photosystem II (PSII) photochemistry (ΦPSII). While at the feeding zone the quantum yield of regulated non-photochemical energy loss in PSII (ΦNPQ) did not change, at the whole leaf level there was a significant increase. As a result, at the feeding zone a significant increase in the quantum yield of non-regulated energy loss in PSII (ΦNO) occurred, but there was no change at the whole leaf level compared to that before feeding, indicating no change in singlet oxygen (1O2) formation. The decreased ΦPSII after feeding was due to a decreased fraction of open reaction centers (qp), since the efficiency of open PSII reaction centers to utilize the light energy (Fv′/Fm′) did not differ before and after feeding. The decreased fraction of open reaction centers resulted in increased excess excitation energy (EXC) at the feeding zone and at the whole leaf level, while hydrogen peroxide (H2O2) production was detected only at the feeding zone. Although the whole leaf PSII efficiency decreased compared to that before feeding, the maximum efficiency of PSII photochemistry (Fv/Fm), and the efficiency of the water-splitting complex on the donor side of PSII (Fv/Fo), did not differ to that before feeding, thus they cannot be considered as sensitive parameters to monitor biotic stress effects. Chlorophyll fluorescence imaging analysis proved to be a good indicator to monitor even short-term impacts of insect herbivory on photosynthetic function, and among the studied parameters, the reduction status of the plastoquinone pool (qp) was the most sensitive and suitable indicator to probe photosynthetic function under biotic stress.
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Stamelou ML, Sperdouli I, Pyrri I, Adamakis IDS, Moustakas M. Hormetic Responses of Photosystem II in Tomato to Botrytis cinerea. PLANTS 2021; 10:plants10030521. [PMID: 33802218 PMCID: PMC8000511 DOI: 10.3390/plants10030521] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/02/2021] [Accepted: 03/07/2021] [Indexed: 02/07/2023]
Abstract
Botrytis cinerea, a fungal pathogen that causes gray mold, is damaging more than 200 plant species, and especially tomato. Photosystem II (PSII) responses in tomato (Solanum lycopersicum L.) leaves to Botrytis cinerea spore suspension application were evaluated by chlorophyll fluorescence imaging analysis. Hydrogen peroxide (H2O2) that was detected 30 min after Botrytis application with an increasing trend up to 240 min, is possibly convening tolerance against B. cinerea at short-time exposure, but when increasing at relative longer exposure, is becoming a damaging molecule. In accordance, an enhanced photosystem II (PSII) functionality was observed 30 min after application of B. cinerea, with a higher fraction of absorbed light energy to be directed to photochemistry (ΦPSΙΙ). The concomitant increase in the photoprotective mechanism of non-photochemical quenching of photosynthesis (NPQ) resulted in a significant decrease in the dissipated non-regulated energy (ΦNO), indicating a possible decreased singlet oxygen (1O2) formation, thus specifying a modified reactive oxygen species (ROS) homeostasis. Therefore, 30 min after application of Botrytis spore suspension, before any visual symptoms appeared, defense response mechanisms were triggered, with PSII photochemistry to be adjusted by NPQ in a such way that PSII functionality to be enhanced, but being fully inhibited at the application spot and the adjacent area, after longer exposure (240 min). Hence, the response of tomato PSII to B. cinerea, indicates a hormetic temporal response in terms of “stress defense response” and “toxicity”, expanding the features of hormesis to biotic factors also. The enhanced PSII functionality 30 min after Botrytis application can possible be related with the need of an increased sugar production that is associated with a stronger plant defense potential through the induction of defense genes.
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Affiliation(s)
- Maria-Lavrentia Stamelou
- Section of Botany, Department of Biology, National and Kapodistrian University of Athens, GR-15784 Athens, Greece; (M.-L.S.); (I.-D.S.A.)
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organization–Demeter, Thermi, GR-57001 Thessaloniki, Greece;
| | - Ilektra Sperdouli
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organization–Demeter, Thermi, GR-57001 Thessaloniki, Greece;
| | - Ioanna Pyrri
- Section of Ecology & Systematics, Department of Biology, National and Kapodistrian University of Athens, GR-15784 Athens, Greece;
| | - Ioannis-Dimosthenis S. Adamakis
- Section of Botany, Department of Biology, National and Kapodistrian University of Athens, GR-15784 Athens, Greece; (M.-L.S.); (I.-D.S.A.)
| | - Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
- Correspondence:
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Babina D, Podobed M, Bondarenko E, Kazakova E, Bitarishvili S, Podlutskii M, Mitsenyk A, Prazyan A, Gorbatova I, Shesterikova E, Volkova P. Seed Gamma Irradiation of Arabidopsis thaliana ABA-Mutant Lines Alters Germination and Does Not Inhibit the Photosynthetic Efficiency of Juvenile Plants. Dose Response 2021; 18:1559325820979249. [PMID: 33456412 PMCID: PMC7783891 DOI: 10.1177/1559325820979249] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 11/16/2022] Open
Abstract
Plant growth response to γ-irradiation includes stimulating or inhibitory effects
depending on plant species, dose applied, stage of ontogeny and other factors.
Previous studies showed that responses to irradiation could depend on ABA
accumulation and signaling. To elucidate the role of ABA in growth and
photosynthetic responses to irradiation, lines Col-8, abi3-8
and aba3 -1 of Arabidopsis thaliana were used.
Seeds were γ-irradiated using 60Co in the dose range 50-150 Gy. It
was revealed that the dose of 150 Gy affected germination parameters of
aba3 -1 and Col-8 lines, while abi3-8 line
was the most resistant to the studied doses and even showed faster germination
at early hours after γ-irradiation at 50 Gy. These results suggest that
susceptibility to ABA is probably more important for growth response to
γ-irradiation than ABA synthesis. The photosynthetic functioning of 16-day-old
plants mainly was not disturbed by γ-irradiation of seeds, and no indication of
photosystem II photoinhibition was noticed, revealing the robustness of the
photosynthetic system of A. thaliana. Glutathione peroxidase
activity and ABA concentrations in plant tissues were not affected in the
studied dose range. These results contribute to the understanding of germination
and photosynthesis fine-tuning and of mechanisms of plant tolerance to ionizing
radiation.
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Affiliation(s)
- Darya Babina
- Russian Institute of Radiology and Agroecology, Obninsk, Russian Federation
| | - Marina Podobed
- Russian Institute of Radiology and Agroecology, Obninsk, Russian Federation
| | | | - Elizaveta Kazakova
- Russian Institute of Radiology and Agroecology, Obninsk, Russian Federation
| | - Sofia Bitarishvili
- Russian Institute of Radiology and Agroecology, Obninsk, Russian Federation
| | - Mikhail Podlutskii
- Russian Institute of Radiology and Agroecology, Obninsk, Russian Federation
| | - Anastasia Mitsenyk
- Russian Institute of Radiology and Agroecology, Obninsk, Russian Federation
| | - Alexander Prazyan
- Russian Institute of Radiology and Agroecology, Obninsk, Russian Federation
| | - Irina Gorbatova
- Russian Institute of Radiology and Agroecology, Obninsk, Russian Federation
| | | | - Polina Volkova
- Russian Institute of Radiology and Agroecology, Obninsk, Russian Federation
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Adamakis IDS, Sperdouli I, Hanć A, Dobrikova A, Apostolova E, Moustakas M. Rapid Hormetic Responses of Photosystem II Photochemistry of Clary Sage to Cadmium Exposure. Int J Mol Sci 2020; 22:E41. [PMID: 33375193 PMCID: PMC7793146 DOI: 10.3390/ijms22010041] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 12/11/2022] Open
Abstract
Five-day exposure of clary sage (Salvia sclarea L.) to 100 μM cadmium (Cd) in hydroponics was sufficient to increase Cd concentrations significantly in roots and aboveground parts and affect negatively whole plant levels of calcium (Ca) and magnesium (Mg), since Cd competes for Ca channels, while reduced Mg concentrations are associated with increased Cd tolerance. Total zinc (Zn), copper (Cu), and iron (Fe) uptake increased but their translocation to the aboveground parts decreased. Despite the substantial levels of Cd in leaves, without any observed defects on chloroplast ultrastructure, an enhanced photosystem II (PSII) efficiency was observed, with a higher fraction of absorbed light energy to be directed to photochemistry (ΦPSΙΙ). The concomitant increase in the photoprotective mechanism of non-photochemical quenching of photosynthesis (NPQ) resulted in an important decrease in the dissipated non-regulated energy (ΦNO), modifying the homeostasis of reactive oxygen species (ROS), through a decreased singlet oxygen (1O2) formation. A basal ROS level was detected in control plant leaves for optimal growth, while a low increased level of ROS under 5 days Cd exposure seemed to be beneficial for triggering defense responses, and a high level of ROS out of the boundaries (8 days Cd exposure), was harmful to plants. Thus, when clary sage was exposed to Cd for a short period, tolerance mechanisms were triggered. However, exposure to a combination of Cd and high light or to Cd alone (8 days) resulted in an inhibition of PSII functionality, indicating Cd toxicity. Thus, the rapid activation of PSII functionality at short time exposure and the inhibition at longer duration suggests a hormetic response and describes these effects in terms of "adaptive response" and "toxicity", respectively.
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Affiliation(s)
| | - Ilektra Sperdouli
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organization—Demeter, Thermi, 57001 Thessaloniki, Greece;
| | - Anetta Hanć
- Department of Trace Analysis, Faculty of Chemistry, Adam Mickiewicz University, 61-614 Poznań, Poland;
| | - Anelia Dobrikova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (A.D.); (E.A.)
| | - Emilia Apostolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria; (A.D.); (E.A.)
| | - Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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Agathokleous E, Kitao M, Calabrese EJ. Hormesis: Highly Generalizable and Beyond Laboratory. TRENDS IN PLANT SCIENCE 2020; 25:1076-1086. [PMID: 32546350 DOI: 10.1016/j.tplants.2020.05.006] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/13/2020] [Accepted: 05/20/2020] [Indexed: 05/17/2023]
Abstract
Hormesis is a biphasic dose-response relationship with contrasting effects of low versus high doses of stress. Hormesis is rapidly developing in plant science research and has wide implications for risk assessment, stress biology, and agriculture. Here, we explore selected areas of importance to the concept of hormesis and suggest that hormesis is a highly generalizable phenomenon. We address the questions of whether hormesis occurs in high-risk groups or in response to mixtures of stress-inducing agents, whether there is a single biological mechanism of hormesis, and what the temporal features of hormesis are.
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Affiliation(s)
- Evgenios Agathokleous
- Key Laboratory of Agrometeorology of Jiangsu Province, Institute of Ecology, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
| | - Mitsutoshi Kitao
- Hokkaido Research Center, Forestry and Forest Products Research Institute (FFPRI), Forest Research and Management Organization, 7 Hitsujigaoka, Sapporo, Hokkaido 062-8516, Japan
| | - Edward J Calabrese
- Department of Public Health, Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA 01003, USA
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15
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Alkimin GDD, Santos J, Soares AMVM, Nunes B. Ecotoxicological effects of the azole antifungal agent clotrimazole on the macrophyte species Lemna minor and Lemna gibba. Comp Biochem Physiol C Toxicol Pharmacol 2020; 237:108835. [PMID: 32585366 DOI: 10.1016/j.cbpc.2020.108835] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/16/2020] [Accepted: 06/19/2020] [Indexed: 12/11/2022]
Abstract
Pharmaceuticals are a large and diverse group of compounds used to treat, prevent and diagnose disease. Among these, a group that has been recently detected in the aquatic environment is that of the azole compounds, commonly used as antifungals. Clotrimazole (CLO) is a nonbiodegradable persistent azole compound, with broad-spectrum antifungal activity for which virtually no toxicological data are available, especially towards aquatic plants. The few existent data point to a documented interference with cytochrome P450 system of exposed organisms. Therefore, the aim of this paper was to evaluate the ecotoxicological effects of the fungicide CLO on two aquatic macrophyte species, namely, Lemna minor and Lemna gibba. To attain this purpose, an acute assay (96 h) was performed with both species being exposed to CLO, in a concentration range of 0 to 5 μg L-1. The analyzed endpoints were levels of chlorophyll a and b, total, carotenoids, catalase (CAT) and glutathione -s-transferases activities (GSTs). In general, CLO exposure caused some minor alterations in L. minor and L. gibba pigment contents. Antioxidant enzymes exhibited a different pattern in both species, since the highest concentrations of CLO caused an increase on CAT activity, and a decrease on GSTs activity in L. minor, and the opposite in L. gibba, reflected by a decrease on CAT activity and an increase on GSTs activity in all tested concentrations. These results demonstrate that CLO exposure resulted in potential deleterious effects on macrophytes, namely with the involvement of the antioxidant defense mechanisms that were likely deployed to cope with pro-oxidative conditions established by CLO.
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Affiliation(s)
- Gilberto Dias de Alkimin
- Department of Biology, Aveiro University, Campus de Santiago, 3810-193 Aveiro, Portugal; Centre for Environmental and Marine Studies (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
| | - João Santos
- Department of Biology, Aveiro University, Campus de Santiago, 3810-193 Aveiro, Portugal
| | - Amadeu M V M Soares
- Department of Biology, Aveiro University, Campus de Santiago, 3810-193 Aveiro, Portugal; Centre for Environmental and Marine Studies (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro, Portugal
| | - Bruno Nunes
- Department of Biology, Aveiro University, Campus de Santiago, 3810-193 Aveiro, Portugal; Centre for Environmental and Marine Studies (CESAM), Campus de Santiago, Universidade de Aveiro, 3810-193 Aveiro, Portugal
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16
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Agathokleous E, Feng Z, Peñuelas J. Chlorophyll hormesis: Are chlorophylls major components of stress biology in higher plants? THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 726:138637. [PMID: 32330746 DOI: 10.1016/j.scitotenv.2020.138637] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 04/09/2020] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
High oxidative stress inhibits the synthesis and accumulation of chlorophylls, the pigments that absorb and use light. We collated evidence from a diverse array of studies demonstrating that chlorophyll concentration increases in response to low-level stress and decreases in response to high-level stress. These observations were from 33 species, >20 stress-inducing agents, 43 experimental setups and 177 dose responses, suggesting generality. Data meta-analysis indicated that the maximum stimulatory response did not differ significantly among species and agents. The stimulatory response maximized within a defined time window (median = 150-160% of the control response), after which it decreased but remained elevated (median = 120-130% of control response). The common stimulation of chlorophylls by low-level stress indicates that chlorophylls are major components of stress biology, with their increased concentration at low-level stress suggestive of their requirement for normal functioning and health. Increased chlorophyll concentration in response to low-level stress may equip systems with an enhanced capacity for defense against high-level (health-threatening) challenges within defined time windows, such as pollution or herbivores. These developments have wide-ranging implications in ecophysiology, biotic interactions and evolution.
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Affiliation(s)
- Evgenios Agathokleous
- Institute of Ecology, Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
| | - ZhaoZhong Feng
- Institute of Ecology, Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, 08193 Bellaterra, Catalonia, Spain; CREAF, 08193 Cerdanyola del Vallès, Catalonia, Spain
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17
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Moustakas M, Hanć A, Dobrikova A, Sperdouli I, Adamakis IDS, Apostolova E. Spatial Heterogeneity of Cadmium Effects on Salvia sclarea Leaves Revealed by Chlorophyll Fluorescence Imaging Analysis and Laser Ablation Inductively Coupled Plasma Mass Spectrometry. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E2953. [PMID: 31547238 PMCID: PMC6766342 DOI: 10.3390/ma12182953] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 09/01/2019] [Accepted: 09/09/2019] [Indexed: 01/28/2023]
Abstract
In this study, for a first time (according to our knowledge), we couple the methodologies of chlorophyll fluorescence imaging analysis (CF-IA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), in order to investigate the effects of cadmium (Cd) accumulation on photosystem II (PSII) photochemistry. We used as plant material Salvia sclarea that grew hydroponically with or without (control) 100 μM Cd for five days. The spatial heterogeneity of a decreased effective quantum yield of electron transport (ΦPSΙΙ) that was observed after exposure to Cd was linked to the spatial pattern of high Cd accumulation. However, the high increase of non-photochemical quenching (NPQ), at the leaf part with the high Cd accumulation, resulted in the decrease of the quantum yield of non-regulated energy loss (ΦNO) even more than that of control leaves. Thus, S. sclarea leaves exposed to 100 μM Cd exhibited lower reactive oxygen species (ROS) production as singlet oxygen (1O2). In addition, the increased photoprotective heat dissipation (NPQ) in the whole leaf under Cd exposure was sufficient enough to retain the same fraction of open reaction centers (qp) with control leaves. Our results demonstrated that CF-IA and LA-ICP-MS could be successfully combined to monitor heavy metal effects and plant tolerance mechanisms.
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Affiliation(s)
- Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
| | - Anetta Hanć
- Department of Trace Element Analysis by Spectroscopy Method, Faculty of Chemistry, Adam Mickiewicz University, 61 614 Poznań, Poland.
| | - Anelia Dobrikova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Science, 1113 Sofia, Bulgaria.
| | - Ilektra Sperdouli
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organization-Demeter, Thermi, 57001 Thessaloniki, Greece.
| | | | - Emilia Apostolova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Science, 1113 Sofia, Bulgaria.
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Sperdouli I, Moustaka J, Antonoglou O, Adamakis IDS, Dendrinou-Samara C, Moustakas M. Leaf Age-Dependent Effects of Foliar-Sprayed CuZn Nanoparticles on Photosynthetic Efficiency and ROS Generation in Arabidopsis thaliana. MATERIALS (BASEL, SWITZERLAND) 2019; 12:E2498. [PMID: 31390827 PMCID: PMC6695995 DOI: 10.3390/ma12152498] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 07/27/2019] [Accepted: 08/03/2019] [Indexed: 12/15/2022]
Abstract
Young and mature leaves of Arabidopsis thaliana were exposed by foliar spray to 30 mg L-1 of CuZn nanoparticles (NPs). The NPs were synthesized by a microwave-assisted polyol process and characterized by dynamic light scattering (DLS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). CuZn NPs effects in Arabidopsis leaves were evaluated by chlorophyll fluorescence imaging analysis that revealed spatiotemporal heterogeneity of the quantum efficiency of PSII photochemistry (ΦPSΙΙ) and the redox state of the plastoquinone (PQ) pool (qp), measured 30 min, 90 min, 180 min, and 240 min after spraying. Photosystem II (PSII) function in young leaves was observed to be negatively influenced, especially 30 min after spraying, at which point increased H2O2 generation was correlated to the lower oxidized state of the PQ pool.. Recovery of young leaves photosynthetic efficiency appeared only after 240 min of NPs spray when also the level of ROS accumulation was similar to control leaves. On the contrary, a beneficial effect on PSII function in mature leaves after 30 min of the CuZn NPs spray was observed, with increased ΦPSΙΙ, an increased electron transport rate (ETR), decreased singlet oxygen (1O2) formation, and H2O2 production at the same level of control leaves.An explanation for this differential response is suggested.
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Affiliation(s)
- Ilektra Sperdouli
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organisation-Demeter, Thermi, GR-57001 Thessaloniki, Greece
| | - Julietta Moustaka
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
- Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark
| | - Orestis Antonoglou
- Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Ioannis-Dimosthenis S Adamakis
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
- Department of Botany, Faculty of Biology, National and Kapodistrian University of Athens, Athens 157 72, Greece
| | - Catherine Dendrinou-Samara
- Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
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19
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Malea P, Charitonidou K, Sperdouli I, Mylona Z, Moustakas M. Zinc Uptake, Photosynthetic Efficiency and Oxidative Stress in the Seagrass Cymodocea nodosa Exposed to ZnO Nanoparticles. MATERIALS 2019; 12:ma12132101. [PMID: 31261885 PMCID: PMC6651621 DOI: 10.3390/ma12132101] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 06/23/2019] [Accepted: 06/27/2019] [Indexed: 12/20/2022]
Abstract
We characterized zinc oxide nanoparticles (ZnO NPs) by dynamic light scattering (DLS) measurements, and transmission electron microscopy (TEM), while we evaluated photosystem II (PSII) responses, Zn uptake kinetics, and hydrogen peroxide (H2O2) accumulation, in C. nodosa exposed to 5 mg L−1 and 10 mg L−1 ZnO NPs for 4 h, 12 h, 24 h, 48 h and 72 h. Four h after exposure to 10 mg L−1 ZnO NPs, we noticed a disturbance of PSII functioning that became more severe after 12 h. However, after a 24 h exposure to 10 mg L−1 ZnO NPs, we observed a hormetic response, with both time and dose as the basal stress levels needed for induction of the adaptive response. This was achieved through the reduced plastoquinone (PQ) pool, at a 12 h exposure, which mediated the generation of chloroplastic H2O2; acting as a fast acclimation signaling molecule. Nevertheless, longer treatment (48 h and 72 h) resulted in decreasing the photoprotective mechanism to dissipate excess energy as heat (NPQ) and increasing the quantum yield of non-regulated energy loss (ΦNO). This increased the formation of singlet oxygen (1O2), and decreased the fraction of open reaction centers, mostly after a 72-h exposure at 10 mg L−1 ZnO NPs due to increased Zn uptake compared to 5 mg L−1.
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Affiliation(s)
- Paraskevi Malea
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
| | - Katerina Charitonidou
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
- School of Agricultural Sciences, University of Thessaly, GR-38446 Volos, Greece
| | - Ilektra Sperdouli
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
- Institute of Plant Breeding and Genetic Resources, Hellenic Agricultural Organisation-Demeter, Thermi, GR-57001 Thessaloniki, Greece
| | - Zoi Mylona
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece
| | - Michael Moustakas
- Department of Botany, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
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