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Nowroz F, Hasanuzzaman M, Siddika A, Parvin K, Caparros PG, Nahar K, Prasad PV. Elevated tropospheric ozone and crop production: potential negative effects and plant defense mechanisms. FRONTIERS IN PLANT SCIENCE 2024; 14:1244515. [PMID: 38264020 PMCID: PMC10803661 DOI: 10.3389/fpls.2023.1244515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 12/15/2023] [Indexed: 01/25/2024]
Abstract
Ozone (O3) levels on Earth are increasing because of anthropogenic activities and natural processes. Ozone enters plants through the leaves, leading to the overgeneration of reactive oxygen species (ROS) in the mesophyll and guard cell walls. ROS can damage chloroplast ultrastructure and block photosynthetic electron transport. Ozone can lead to stomatal closure and alter stomatal conductance, thereby hindering carbon dioxide (CO2) fixation. Ozone-induced leaf chlorosis is common. All of these factors lead to a reduction in photosynthesis under O3 stress. Long-term exposure to high concentrations of O3 disrupts plant physiological processes, including water and nutrient uptake, respiration, and translocation of assimilates and metabolites. As a result, plant growth and reproductive performance are negatively affected. Thus, reduction in crop yield and deterioration of crop quality are the greatest effects of O3 stress on plants. Increased rates of hydrogen peroxide accumulation, lipid peroxidation, and ion leakage are the common indicators of oxidative damage in plants exposed to O3 stress. Ozone disrupts the antioxidant defense system of plants by disturbing enzymatic activity and non-enzymatic antioxidant content. Improving photosynthetic pathways, various physiological processes, antioxidant defense, and phytohormone regulation, which can be achieved through various approaches, have been reported as vital strategies for improving O3 stress tolerance in plants. In plants, O3 stress can be mitigated in several ways. However, improvements in crop management practices, CO2 fertilization, using chemical elicitors, nutrient management, and the selection of tolerant crop varieties have been documented to mitigate O3 stress in different plant species. In this review, the responses of O3-exposed plants are summarized, and different mitigation strategies to decrease O3 stress-induced damage and crop losses are discussed. Further research should be conducted to determine methods to mitigate crop loss, enhance plant antioxidant defenses, modify physiological characteristics, and apply protectants.
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Affiliation(s)
- Farzana Nowroz
- Department of Agronomy, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Mirza Hasanuzzaman
- Department of Agronomy, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Ayesha Siddika
- Department of Agronomy, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Khursheda Parvin
- Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Pedro Garcia Caparros
- Agronomy Department of Superior School Engineering, University of Almería, Almería, Spain
| | - Kamrun Nahar
- Department of Agricultural Botany, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - P.V. Vara Prasad
- Department of Agronomy, Kansas State University, Manhattan, KS, United States
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Ramya A, Dhevagi P, Poornima R, Avudainayagam S, Watanabe M, Agathokleous E. Effect of ozone stress on crop productivity: A threat to food security. ENVIRONMENTAL RESEARCH 2023; 236:116816. [PMID: 37543123 DOI: 10.1016/j.envres.2023.116816] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/29/2023] [Accepted: 08/01/2023] [Indexed: 08/07/2023]
Abstract
Tropospheric ozone (O3), the most important phytotoxic air pollutant, can deteriorate crop quality and productivity. Notably, satellite and ground-level observations-based multimodel simulations demonstrate that the present and future predicted O3 exposures could threaten food security. Hence, the present study aims at reviewing the phytotoxicity caused by O3 pollution, which threatens the food security. The present review encompasses three major aspects; wherein the past and prevailing O3 concentrations in various regions were compiled at first, followed by discussing the physiological, biochemical and yield responses of economically important crop species, and considering the potential of O3 protectants to alleviate O3-induced phytotoxicity. Finally, the empirical data reported in the literature were quantitatively analysed to show that O3 causes detrimental effect on physiological traits, photosynthetic pigments, growth and yield attributes. The review on prevailing O3 concentrations over various regions, where economically important crop are grown, and their negative impact would support policy makers to implement air pollution regulations and the scientific community to develop countermeasures against O3 phytotoxicity for maintaining food security.
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Affiliation(s)
- Ambikapathi Ramya
- Department of Environmental Sciences, Tamil Nadu Agricultural University, Tamil Nadu, 641003, India
| | - Periyasamy Dhevagi
- Department of Environmental Sciences, Tamil Nadu Agricultural University, Tamil Nadu, 641003, India.
| | - Ramesh Poornima
- Department of Environmental Sciences, Tamil Nadu Agricultural University, Tamil Nadu, 641003, India
| | - S Avudainayagam
- Department of Environmental Sciences, Tamil Nadu Agricultural University, Tamil Nadu, 641003, India
| | - Makoto Watanabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan
| | - Evgenios Agathokleous
- Department of Ecology, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, 210044, China.
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O’Rourke JA, Graham MA. Coupling VIGS with Short- and Long-Term Stress Exposure to Understand the Fiskeby III Iron Deficiency Stress Response. Int J Mol Sci 2022; 24:ijms24010647. [PMID: 36614091 PMCID: PMC9820625 DOI: 10.3390/ijms24010647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/19/2022] [Accepted: 12/26/2022] [Indexed: 12/31/2022] Open
Abstract
Yield loss due to abiotic stress is an increasing problem in agriculture. Soybean is a major crop for the upper Midwestern United States and calcareous soils exacerbate iron deficiency for growers, resulting in substantial yield losses. Fiskeby III is a soybean variety uniquely resistant to a variety of abiotic stresses, including iron deficiency. Previous studies identified a MATE transporter (Glyma.05G001700) associated with iron stress tolerance in Fiskeby III. To understand the function of this gene in the Fiskeby III response to iron deficiency, we coupled its silencing using virus-induced gene silencing with RNAseq analyses at two timepoints. Analyses of these data confirm a role for the MATE transporter in Fiskeby III iron stress responses. Further, they reveal that Fiskeby III induces transcriptional reprogramming within 24 h of iron deficiency stress, confirming that like other soybean varieties, Fiskeby III is able to quickly respond to stress. However, Fiskeby III utilizes novel genes and pathways in its iron deficiency response. Identifying and characterizing these genes and pathways in Fiskeby III provides novel targets for improving abiotic stress tolerance in elite soybean lines.
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Jamal R, Narayan S, Dubey R, Kannaujia R, Rai R, Behera SK, Behera SK, Shirke PA, Pandey V, Barik SK. Response of tropical trees to elevated Ozone: a Free Air Ozone Enrichment study. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 195:238. [PMID: 36574061 DOI: 10.1007/s10661-022-10713-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 08/30/2022] [Indexed: 06/17/2023]
Abstract
Tropospheric ozone (O3) has become one of the main urban air pollutants. In the present study, we assessed impact of ambient and future ground-level O3 on nine commonly growing urban tree species under Free Air Ozone Enrichment (FAOE) condition. During the study period, mean ambient and elevated ozone (EO3) concentrations were 48.59 and 69.62 ppb, respectively. Under EO3 treatment, stomatal density (SD) significantly decreased and guard cell length (GCL) increased in Azadirachta indica, Bougainvillea spectabilis, Plumeria rubra, Saraca asoca and Tabernaemontana divaricata, while SD increased and GCL decreased in Ficus benghalensis and Terminalia arjuna. Proline levels increased in all the nine plant species under EO3 condition. EO3 significantly reduced photosynthetic rate, stomatal conductance (gs), and transpiration rates (E). Only A. indica and N. indicum showed higher gs and E under EO3 treatment. Water use efficiency (WUE) significantly increased in F. benghalensis and decreased in A. indica and T. divaricata. Air Pollution Tolerance Index (APTI) significantly increased in Ficus religiosa and S. asoca whereas it decreased in B. spectabilis and A. indica. Of all the plant species B. spectabilis and A. indica were the most sensitive to EO3 (high gs and less ascorbic acid content) while S. asoca and F. religiosa were the most tolerant (lowgs and more ascorbic acid content). The sensitivity of urban tree species to EO3 is a cause of concern and should be considered for future urban forestry programmes. Our study should guide more such studies to identify tolerant trees for urban air pollution abatement.
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Affiliation(s)
- Rushna Jamal
- Plant Ecology and Climate Change Sciences Division, CSIR-National Botanical Research Institute (CSIR-NBRI), Uttar Pradesh, Rana Pratap Marg, Lucknow, 226001, India
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, India, 201 002
| | - Shiv Narayan
- Plant Ecology and Climate Change Sciences Division, CSIR-National Botanical Research Institute (CSIR-NBRI), Uttar Pradesh, Rana Pratap Marg, Lucknow, 226001, India
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, India, 201 002
| | - Raghvendra Dubey
- Plant Ecology and Climate Change Sciences Division, CSIR-National Botanical Research Institute (CSIR-NBRI), Uttar Pradesh, Rana Pratap Marg, Lucknow, 226001, India
| | - Rekha Kannaujia
- Plant Ecology and Climate Change Sciences Division, CSIR-National Botanical Research Institute (CSIR-NBRI), Uttar Pradesh, Rana Pratap Marg, Lucknow, 226001, India
| | - Richa Rai
- Plant Ecology and Climate Change Sciences Division, CSIR-National Botanical Research Institute (CSIR-NBRI), Uttar Pradesh, Rana Pratap Marg, Lucknow, 226001, India
| | | | - Soumit K Behera
- Plant Ecology and Climate Change Sciences Division, CSIR-National Botanical Research Institute (CSIR-NBRI), Uttar Pradesh, Rana Pratap Marg, Lucknow, 226001, India
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, India, 201 002
| | - Pramod A Shirke
- Plant Ecology and Climate Change Sciences Division, CSIR-National Botanical Research Institute (CSIR-NBRI), Uttar Pradesh, Rana Pratap Marg, Lucknow, 226001, India
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, India, 201 002
| | - Vivek Pandey
- Plant Ecology and Climate Change Sciences Division, CSIR-National Botanical Research Institute (CSIR-NBRI), Uttar Pradesh, Rana Pratap Marg, Lucknow, 226001, India.
- Academy of Scientific and Innovative Research (AcSIR), Uttar Pradesh, Ghaziabad, India, 201 002.
| | - Saroj K Barik
- Plant Ecology and Climate Change Sciences Division, CSIR-National Botanical Research Institute (CSIR-NBRI), Uttar Pradesh, Rana Pratap Marg, Lucknow, 226001, India.
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Lee JH, Goto E. Ozone control as a novel method to improve health-promoting bioactive compounds in red leaf lettuce ( Lactuca sativa L.). FRONTIERS IN PLANT SCIENCE 2022; 13:1045239. [PMID: 36544872 PMCID: PMC9760822 DOI: 10.3389/fpls.2022.1045239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 11/07/2022] [Indexed: 06/17/2023]
Abstract
In this study, we determined the short-term effects of ozone exposure on the growth and accumulation of bioactive compounds in red lettuce leaves grown in a controlled environment plant factory with artificial light, also known as a vertical farm. During cultivation, twenty-day-old lettuce (Lactuca sativa L. var. Redfire) seedlings were exposed to 100 and 200 ppb of ozone concentrations for 72 h. To find out how plants react to ozone and light, complex treatments were done with light and ozone concentrations (100 ppb; 16 h and 200 ppb; 24 h). Ozone treatment with 100 ppb did not show any significant difference in shoot fresh weight compared to that of the control, but the plants exposed to the 200 ppb treatment showed a significant reduction in fresh weight by 1.3 fold compared to the control. The expression of most genes in lettuce plants exposed to 100 and 200 ppb of ozone increased rapidly after 0.5 h and showed a decreasing trend after reaching a peak. Even when exposed to a uniform ozone concentration, the pattern of accumulating bioactive compounds such as total phenolics, antioxidant capacity and total flavonoids varied based on leaf age. At a concentration of 200 ppb, a greater accumulation was found in the third (older) leaf than in the fourth leaf (younger). The anthocyanin of lettuce plants subjected to 100 and 200 ppb concentrations increased continuously for 48 h. Our results suggest that ozone control is a novel method that can effectively increase the accumulation of bioactive compounds in lettuce in a plant factory.
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Affiliation(s)
- Jin-Hui Lee
- Graduate School of Horticulture, Chiba University, Chiba, Japan
| | - Eiji Goto
- Graduate School of Horticulture, Chiba University, Chiba, Japan
- Plant Molecular Research Center, Chiba University, Chiba, Japan
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O’Rourke JA, Morrisey MJ, Merry R, Espina MJ, Lorenz AJ, Stupar RM, Graham MA. Mining Fiskeby III and Mandarin (Ottawa) Expression Profiles to Understand Iron Stress Tolerant Responses in Soybean. Int J Mol Sci 2021; 22:11032. [PMID: 34681702 PMCID: PMC8537376 DOI: 10.3390/ijms222011032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/06/2021] [Accepted: 10/10/2021] [Indexed: 12/13/2022] Open
Abstract
The soybean (Glycine max L. merr) genotype Fiskeby III is highly resistant to a multitude of abiotic stresses, including iron deficiency, incurring only mild yield loss during stress conditions. Conversely, Mandarin (Ottawa) is highly susceptible to disease and suffers severe phenotypic damage and yield loss when exposed to abiotic stresses such as iron deficiency, a major challenge to soybean production in the northern Midwestern United States. Using RNA-seq, we characterize the transcriptional response to iron deficiency in both Fiskeby III and Mandarin (Ottawa) to better understand abiotic stress tolerance. Previous work by our group identified a quantitative trait locus (QTL) on chromosome 5 associated with Fiskeby III iron efficiency, indicating Fiskeby III utilizes iron deficiency stress mechanisms not previously characterized in soybean. We targeted 10 of the potential candidate genes in the Williams 82 genome sequence associated with the QTL using virus-induced gene silencing. Coupling virus-induced gene silencing with RNA-seq, we identified a single high priority candidate gene with a significant impact on iron deficiency response pathways. Characterization of the Fiskeby III responses to iron stress and the genes underlying the chromosome 5 QTL provides novel targets for improved abiotic stress tolerance in soybean.
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Affiliation(s)
| | | | - Ryan Merry
- Department of Genetics and Agronomy, University of Minnesota, St. Paul, MN 55108, USA; (R.M.); (M.J.E.); (A.J.L.); (R.M.S.)
| | - Mary Jane Espina
- Department of Genetics and Agronomy, University of Minnesota, St. Paul, MN 55108, USA; (R.M.); (M.J.E.); (A.J.L.); (R.M.S.)
| | - Aaron J. Lorenz
- Department of Genetics and Agronomy, University of Minnesota, St. Paul, MN 55108, USA; (R.M.); (M.J.E.); (A.J.L.); (R.M.S.)
| | - Robert M. Stupar
- Department of Genetics and Agronomy, University of Minnesota, St. Paul, MN 55108, USA; (R.M.); (M.J.E.); (A.J.L.); (R.M.S.)
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Kask K, Kaurilind E, Talts E, Kännaste A, Niinemets Ü. Combined Acute Ozone and Water Stress Alters the Quantitative Relationships between O 3 Uptake, Photosynthetic Characteristics and Volatile Emissions in Brassica nigra. Molecules 2021; 26:molecules26113114. [PMID: 34070994 PMCID: PMC8197083 DOI: 10.3390/molecules26113114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/20/2021] [Accepted: 05/21/2021] [Indexed: 11/16/2022] Open
Abstract
Ozone (O3) entry into plant leaves depends on atmospheric O3 concentration, exposure time and openness of stomata. O3 negatively impacts photosynthesis rate (A) and might induce the release of reactive volatile organic compounds (VOCs) that can quench O3, and thereby partly ameliorate O3 stress. Water stress reduces stomatal conductance (gs) and O3 uptake and can affect VOC release and O3 quenching by VOC, but the interactive effects of O3 exposure and water stress, as possibly mediated by VOC, are poorly understood. Well-watered (WW) and water-stressed (WS) Brassica nigra plants were exposed to 250 and 550 ppb O3 for 1 h, and O3 uptake rates, photosynthetic characteristics and VOC emissions were measured through 22 h recovery. The highest O3 uptake was observed in WW plants exposed to 550 ppb O3 with the greatest reduction and poorest recovery of gs and A, and elicitation of lipoxygenase (LOX) pathway volatiles 10 min-1.5 h after exposure indicating cellular damage. Ozone uptake was similar in 250 ppb WW and 550 ppb WS plants and, in both treatments, O3-dependent reduction in photosynthetic characteristics was moderate and fully reversible, and VOC emissions were little affected. Water stress alone did not affect the total amount and composition of VOC emissions. The results indicate that drought ameliorated O3 stress by reducing O3 uptake through stomatal closure and the two stresses operated in an antagonistic manner in B. nigra.
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Affiliation(s)
- Kaia Kask
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51006 Tartu, Estonia; (E.K.); (E.T.); (A.K.); (Ü.N.)
- Correspondence:
| | - Eve Kaurilind
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51006 Tartu, Estonia; (E.K.); (E.T.); (A.K.); (Ü.N.)
| | - Eero Talts
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51006 Tartu, Estonia; (E.K.); (E.T.); (A.K.); (Ü.N.)
| | - Astrid Kännaste
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51006 Tartu, Estonia; (E.K.); (E.T.); (A.K.); (Ü.N.)
| | - Ülo Niinemets
- Chair of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51006 Tartu, Estonia; (E.K.); (E.T.); (A.K.); (Ü.N.)
- Estonian Academy of Sciences, Kohtu 6, 10130 Tallinn, Estonia
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Tisdale RH, Zobel RW, Burkey KO. Tropospheric ozone rapidly decreases root growth by altering carbon metabolism and detoxification capability in growing soybean roots. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 766:144292. [PMID: 33418251 DOI: 10.1016/j.scitotenv.2020.144292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 11/27/2020] [Accepted: 11/28/2020] [Indexed: 06/12/2023]
Abstract
High tropospheric ozone (O3) concentrations lead to significant global soybean (Glycine max) yield reductions. Research concerning O3 impacts on soybean has focused on the contributions of above-ground tissues. In this study, Mandarin (Ottawa) (O3-sensitive) and Fiskeby III (O3-tolerant) soybean genotypes provide contrasting materials to investigate O3 effects on root growth. We compared root morphological and proteomic changes when 16-day-old plants were treated with charcoal-filtered (CF) air or elevated O3 (80 ppb O3 for 7 h/day) in continuously stirred-tank reactors (CSTR) for 7 days. Our results showed that in Mandarin (Ottawa), decreased expression of enzymes involved in the tricarboxylic acid (TCA) cycle contributes to reduction of root biomass and diameter under elevated O3. In contrast, O3 tolerance in Fiskeby III roots was associated with O3-dependent induction of enzymes involved in glycolysis and O3-independent expression of enzymes involved in the ascorbate-glutathione cycle. We conclude that a decreased abundance of key redox enzymes in roots due to limited carbon availability rapidly alters root growth under O3 stress. However, maintaining a high abundance of enzymes associated with redox status and detoxification capability contributes to overall O3 tolerance in roots.
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Affiliation(s)
- Ripley H Tisdale
- U.S. Department of Agriculture, Agricultural Research Service, Plant Science Research Unit, Raleigh, 27607, NC, USA; Department of Crop and Soil Sciences, North Carolina State University, Raleigh, 27695, NC, USA.
| | - Richard W Zobel
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, 27695, NC, USA
| | - Kent O Burkey
- U.S. Department of Agriculture, Agricultural Research Service, Plant Science Research Unit, Raleigh, 27607, NC, USA; Department of Crop and Soil Sciences, North Carolina State University, Raleigh, 27695, NC, USA
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Goumenaki E, González-Fernández I, Barnes JD. Ozone uptake at night is more damaging to plants than equivalent day-time flux. PLANTA 2021; 253:75. [PMID: 33629150 PMCID: PMC7904732 DOI: 10.1007/s00425-021-03580-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 01/30/2021] [Indexed: 05/21/2023]
Abstract
MAIN CONCLUSION Plants exposed to equivalent ozone fluxes administered during day-time versus night-time exhibited greater losses in biomass at night and this finding is attributed to night-time depletion of cell wall-localised ascorbate. The present study employed Lactuca sativa and its closest wild relative, L. serriola, to explore the relative sensitivity of plants to ozone-induced oxidative stress during day-time versus night-time. By controlling atmospheric ozone concentration and measuring stomatal conductance, equivalent ozone uptake into leaves was engineered during day and night, and consequences on productivity and net CO2 assimilation rate were determined. Biomass losses attributable to ozone were significantly greater when an equivalent dose of ozone was taken-up by foliage at night compared to the day. Linkages between ozone impacts and ascorbic acid (AA) content, redox status and cellular compartmentation were probed in both species. Leaf AA pools were depleted by exposure of plants to darkness, and then AA levels in the apoplast and symplast were monitored on subsequent transfer of plants to the light. Apoplast AA appeared to be more affected by light-dark transition than the symplast pool. Moreover, equivalent ozone fluxes administered to leaves with contrasting AA levels resulted in contrasting effects on the light-saturated rate of CO2 assimilation (Asat) in both species. Once apoplast AA content recovered to pre-treatment levels, the same ozone flux resulted in no impacts on Asat. The results of the present investigation reveal that plants are significantly more sensitive to equivalent ozone fluxes taken-up at night compared with those during the day and were consistent with diel shifts in apoplast AA content and/or redox status. Furthermore, findings suggest that some thought should be given to weighing regional models of ozone impacts for extraordinary night-time ozone impacts.
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Affiliation(s)
- Eleni Goumenaki
- Plant and Microbial Biology, School of Natural and Environmental Science [SNES], Devonshire Building, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK.
- School of Agricultural Sciences, Hellenic Mediterranean University, P.O. Box 1939, GR-71004, Heraklion, Crete, Greece.
| | - Ignacio González-Fernández
- Plant and Microbial Biology, School of Natural and Environmental Science [SNES], Devonshire Building, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK
- Ecotoxicology of Air Pollution, CIEMAT, Avda. Complutense, 40.28040, Madrid, Spain
| | - Jeremy D Barnes
- Plant and Microbial Biology, School of Natural and Environmental Science [SNES], Devonshire Building, Newcastle University, Newcastle Upon Tyne, NE1 7RU, UK
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