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Hoshika Y, Agathokleous E, Moura BB, Paoletti E. Ozone risk assessment with free-air controlled exposure (FACE) experiments: A critical revisit. ENVIRONMENTAL RESEARCH 2024; 255:119215. [PMID: 38782333 DOI: 10.1016/j.envres.2024.119215] [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: 02/05/2024] [Revised: 05/03/2024] [Accepted: 05/21/2024] [Indexed: 05/25/2024]
Abstract
Since risk assessments of tropospheric ozone (O3) are crucial for agricultural and forestry sectors, there is a growing body for realistic assessments by a stomatal flux-based approach in Free-Air Controlled Exposure (FACE) facilities. Ozone risks are normally described as relative risks (RRs), which are calculated by assuming the biomass or yield at zero O3 dose as "reference". However, the estimation of the reference biomass or yield is challenging due to a lack of O3-clean-air treatment at the FACEs and the extrapolation without data in a low O3 range increases the bias for estimating the reference values. Here, we reviewed a current methodology for the risk assessment at FACEs and presented a simple and effective way ("modified Paoletti's approach") of defining RRs just using biomass or yield data with a range of expected impacts under the FACE conditions hypothesizing three possible scenarios based on prediction limits using 95% credible intervals (CI) (1. Best fit using the intercept as reference, 2. Optimistic scenario using a lower CI and 3. Worst scenario using an upper CI). As a result, O3-sensitive species show a relatively narrow effect range (optimistic vs. worst scenario) whereas a wide range of response may be possibly taken in resistant species. Showing a possible effect range allows for a comprehensive understanding of the potential risks and its uncertainties related to a species sensitivity to O3. As a supporting approach, we also recommend to use scientifically relevant tools (i.e., ethylenediurea treatments; mechanistic plant models) for strengthening the obtained results for the RRs against O3. Interestingly, the moderately sensitive or resistant species showed non-linear rather than linear dose-response relationships, suggesting a need for the flexible functional form for the risk assessment to properly describe the complex plant response such as hormesis, which depends on their plasticity to O3 stress.
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Affiliation(s)
- Yasutomo Hoshika
- Institute of Research on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Via Madonna del Piano, I-50019, Sesto Fiorentino, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy.
| | - Evgenios Agathokleous
- School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology (NUIST), Ningliu Rd. 219, Nanjing, Jiangsu, 210044, China
| | - Barbara Baesso Moura
- Institute of Research on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Via Madonna del Piano, I-50019, Sesto Fiorentino, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy
| | - Elena Paoletti
- Institute of Research on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Via Madonna del Piano, I-50019, Sesto Fiorentino, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy
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Tanaka R, Kawamata K, Urashima M, Matsuda K, Izuta T, Watanabe M. Vertical gradient of needle ozone uptake within the canopy of Cryptomeria japonica. ENVIRONMENTAL RESEARCH 2024; 258:119464. [PMID: 38908659 DOI: 10.1016/j.envres.2024.119464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 06/10/2024] [Accepted: 06/19/2024] [Indexed: 06/24/2024]
Abstract
Leaf ozone uptake through the stomata is an important index for the ozone risk assessments on trees. Stomatal conductance (gs) and ozone concentration ([O3]), determinants of the leaf ozone uptake, are known to show vertical gradients within a tree canopy. However, less is known about the within-canopy vertical gradient of leaf ozone uptake. This study was aimed to elucidate how the vertical gradient of [O3] and gs affect needle ozone uptake within a canopy of mature Cryptomeria japonica trees in a suburban forest at Tokyo, Japan. For this purpose, a multilayer gas exchange model was applied to estimate the vertical gradient of needle gs and the accumulated ozone uptake during the study period (POD1, Phytotoxic Ozone Dose above a threshold of 1 nmol m-2 s-1). In addition, we also tested several scenarios of vertical gradient of [O3] within the canopy for sensitivity analysis. The POD1 was declined from the top to the bottom of the canopy. This tendency strongly depended on the vertical gradient of gs and was hardly affected by the changes in simulated vertical reductions of the [O3]. We further assessed the photosynthesis of sunlit needles (needles absorbing both direct and diffuse light) and shaded needles (needles only absorbing diffuse light). The photosynthesis of shaded needles in the upper half of the canopy made a great contribution to the entire canopy photosynthesis. In addition, given that their POD1 was lower than that of sunlit needles, ozone may affect sunlit and shaded needles differently. We concluded that these considerations should be incorporated into modeling of the calculation of ozone uptake for mature trees to make accurate predictions of the ozone effects on trees at the canopy scale.
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Affiliation(s)
- Ryoji Tanaka
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan
| | - Kenta Kawamata
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan
| | - Miyu Urashima
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan
| | - Kazuhide Matsuda
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan
| | - Takeshi Izuta
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan
| | - Makoto Watanabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509, Japan.
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Hoshika Y, Moura BB, Cotrozzi L, Nali C, Alfarraj S, Rennenberg H, Paoletti E. An assessment of ozone risk for date palm suggests that phytotoxic ozone dose nonlinearly affects carbon gain. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 342:123143. [PMID: 38097156 DOI: 10.1016/j.envpol.2023.123143] [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: 08/23/2023] [Revised: 12/05/2023] [Accepted: 12/10/2023] [Indexed: 12/17/2023]
Abstract
Tropospheric ozone (O3) is a significant phytotoxic air pollutant that has a negative impact on plant carbon gain. Although date palm (Phoenix dactylifera L.) is a globally important crop in arid or semi-arid regions, so far O3 risk assessment for this species has not been reported. This study estimated leaf- and plant-level photosynthetic CO2 uptake for understanding how elevated levels of O3 affects date palm biomass growth. Ozone risks to date palm plants were assessed based on exposure- (AOT40) or flux-based indices (Phytotoxic Ozone Dose, PODy, where y is a threshold of uptake). For this purpose, plants were exposed to three levels of O3 [ambient air, AA (45 ppb as daily average); 1.5 × AA; 2.0 × AA] for 92 days in an O3 Free-Air Controlled Exposure facility. According to the model simulations, the negative effects of O3 on plant-level net photosynthetic CO2 uptake were attributed to reduced gross photosynthetic carbon gain and increased respiratory carbon loss. Season-long O3 exposure and elevated temperatures promoted the negative O3 effect because of a further increase of respiratory carbon loss, which was caused by increased leaf temperature due to stomatal closure. POD1 nonlinearly affected the photosynthetic CO2 uptake, which was closely related to the variation of dry mass increment during the experiment. Although the dose-response relationship suggested that a low O3 dose (POD1 < 5.2 mmol m-2) may even positively affect photosynthetic CO2 uptake in date palms, stomatal O3 uptake at the current ambient O3 levels has potentially a negative impact on date palm growth. The results indicate 5.8 mmol m-2 POD1 or 21.1 ppm h AOT40 as critical levels corresponding to a 4% reduction of net CO2 uptake for date palm, suggesting that this species can be identified as a species moderately sensitive to O3.
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Affiliation(s)
- Yasutomo Hoshika
- Institute of Research on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Sede Secondaria di Firenze, Via Madonna del Piano, 50019, Sesto Fiorentino, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy.
| | - Barbara Baesso Moura
- Institute of Research on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Sede Secondaria di Firenze, Via Madonna del Piano, 50019, Sesto Fiorentino, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy
| | - Lorenzo Cotrozzi
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy; CIRSEC, Centre for Climate Change Impact, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy
| | - Cristina Nali
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy; CIRSEC, Centre for Climate Change Impact, University of Pisa, Via del Borghetto 80, 56124, Pisa, Italy
| | - Saleh Alfarraj
- College of Sciences, King Saud University, PO Box 2455, Riyad, 11451, Saudi Arabia
| | - Heinz Rennenberg
- College of Sciences, King Saud University, PO Box 2455, Riyad, 11451, Saudi Arabia; Chair of Tree Physiology, Faculty of Environment and Natural Resources, Institute of Forest Sciences, Albert-Ludwigs-University Freiburg, Georges-Köhler-Allee 53, 79110, Freiburg, Germany; Center of Molecular Ecophysiology (CMEP), College of Resources and Environment, Southwest University No. 2, Tiansheng Road, Beibei District, 400715, Chongqing, PR China
| | - Elena Paoletti
- Institute of Research on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Sede Secondaria di Firenze, Via Madonna del Piano, 50019, Sesto Fiorentino, Italy; NBFC, National Biodiversity Future Center, Palermo, 90133, Italy
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4
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Hoshika Y, Haworth M, Watanabe M, Koike T. Interactive effect of leaf age and ozone on mesophyll conductance in Siebold's beech. PHYSIOLOGIA PLANTARUM 2020; 170:172-186. [PMID: 32394437 DOI: 10.1111/ppl.13121] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 05/01/2020] [Accepted: 05/07/2020] [Indexed: 06/11/2023]
Abstract
Mesophyll conductance (Gm ) is one of the most important factors determining photosynthesis. Tropospheric ozone (O3 ) is known to accelerate leaf senescence and causes a decline of photosynthetic activity in leaves. However, the effects of age-related variation of O3 on Gm have not been well investigated, and we, therefore, analysed leaf gas exchange data in a free-air O3 exposure experiment on Siebold's beech with two levels (ambient and elevated O3 : 28 and 62 nmol mol-1 as daylight average, respectively). In addition, we examined whether O3 -induced changes on leaf morphology (leaf mass per area, leaf density and leaf thickness) may affect CO2 diffusion inside leaves. We found that O3 damaged the photosynthetic biochemistry progressively during the growing season. The Gm was associated with a reduced photosynthesis in O3 -fumigated Siebold's beech in August. The O3 -induced reduction of Gm was negatively correlated with leaf density, which was increased by elevated O3 , suggesting that the reduction of Gm was accompanied by changes in the physical structure of mesophyll cells. On the other hand, in October, the O3 -induced decrease of Gm was diminished because Gm decreased due to leaf senescence regardless of O3 treatment. The reduction of photosynthesis in senescent leaves after O3 exposure was mainly due to a decrease of maximum carboxylation rate (Vcmax ) and/or maximum electron transport rate (Jmax ) rather than diffusive limitations to CO2 transport such as Gm . A leaf age×O3 interaction of photosynthetic response will be a key for modelling photosynthesis in O3 -polluted environments.
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Affiliation(s)
- Yasutomo Hoshika
- Institute of Research on Terrestrial Ecosystems (IRET), National Research Council of Italy (CNR), Via Madonna del Piano, Sesto Fiorentino, I-50019, Italy
| | - Matthew Haworth
- Institute of Sustainable Plant Protection (IPSP), National Research Council of Italy (CNR), Via Madonna del Piano, Sesto Fiorentino, I-50019, Italy
| | - Makoto Watanabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, 183-8509, Japan
| | - Takayoshi Koike
- Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8689, Japan
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5
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Kinose Y, Fukamachi Y, Okabe S, Hiroshima H, Watanabe M, Izuta T. Toward an impact assessment of ozone on plant carbon fixation using a process-based plant growth model: A case study of Fagus crenata grown under different soil nutrient levels. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 716:137008. [PMID: 32059294 DOI: 10.1016/j.scitotenv.2020.137008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/28/2020] [Accepted: 01/28/2020] [Indexed: 06/10/2023]
Abstract
Ozone (O3) in the troposphere, an air pollutant with phytotoxicity, is considered as a driver of global warming, because it reduces plant carbon fixation. Recently, a process-based plant growth model has been used in evaluating the O3 impacts on plants (Schauberger et al., 2019). To make the evaluation more rigorous, we developed a plant growth model and clarified the key factors driving O3-induced change in the whole-plant carbon fixation amount (Cfix). Fagus crenata seedlings were exposed to three O3 levels (charcoal-filtered air or 1.0- or 1.5-folds ambient [O3]) with three soil fertilization levels (non-, low-, or high-fertilized), i.e., a total of nine treatments. The Cfix was reduced in non- and low-fertilized treatments but was unaffected in high-fertilized treatment by O3 fumigation. Our plant growth model could simulate Cfix accurately (<10% error) by considering the impacts of O3 on plant leaf area and photosynthetic capacities, including maximum velocities of carboxylation and electron transport (Vcmax and Jmax, respectively), and the initial slope and convexity of the curve of the electron transport velocity response to photosynthetic photon flux density (φ and θ, respectively). Furthermore, the model revealed that changes in Vcmax and Jmax, φ and θ, or leaf area, caused by 1.5-folds the ambient [O3] fumigation resulted in the following Cfix changes: -1.6, -5.8, or -16.4% in non-fertilized seedlings, -4.1, -4.4, or -9.3% in low-fertilized seedlings, and -4.6, -7.6, or +5.8% in high-fertilized seedlings. Therefore, photosynthetic capacities (particularly φ and θ) and leaf area are important factors influencing the impact of O3 on Cfix of F. crenata seedlings grown under various fertilization levels. Further, the impacts of O3 and soil nutrient on these photosynthetic capacities and plant leaf area should be considered to predict O3-induced changes in carbon fixation by forest tree species using the process-based plant growth model.
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Affiliation(s)
- Yoshiyuki Kinose
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Yoshinobu Fukamachi
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Shigeaki Okabe
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Hiroka Hiroshima
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Makoto Watanabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Takeshi Izuta
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
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6
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Zhang L, Hoshika Y, Carrari E, Cotrozzi L, Pellegrini E, Paoletti E. Effects of nitrogen and phosphorus imbalance on photosynthetic traits of poplar Oxford clone under ozone pollution. JOURNAL OF PLANT RESEARCH 2018; 131:915-924. [PMID: 30426334 DOI: 10.1007/s10265-018-1071-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 10/05/2018] [Indexed: 05/28/2023]
Abstract
Ozone (O3) pollution and the availability of nitrogen (N) and phosphorus (P) in the soil both affect plant photosynthesis and chlorophyll (Chl) content, but the interaction of O3 and nutrition is unclear. We postulated that the nutritional condition changes plant photosynthetic responses to O3. An O3-sensitive poplar clone (Oxford) was subject to two N levels (N0, 0 kg N ha- 1; N80, 80 kg N ha- 1), two P levels (P0, 0 kg P ha- 1; P80, 80 kg P ha- 1) and three levels of O3 exposure (ambient concentration, AA; 1.5 × AA; 2.0 × AA) over a growing season in an O3 free air controlled exposure (FACE) facility. The daily change of leaf gas exchange and dark respiration (Rd) were investigated at mid-summer (August). Chl a fluorescence was measured three times in July, August and September. At the end of the growing season, Chl content was measured. It was found that Chl content, the maximum quantum yield (Fv/Fm), Chl a fluorescence performance index (PI) and gas exchange were negatively affected by elevated O3. Phosphorus may mitigate the O3-induced reduction of the ratio of photosynthesis to stomatal conductance, while it exacerbated the O3-induced loss of Fv/Fm. Nitrogen alleviated negative effects of O3 on Fv/Fm and PI in July. Ozone-induced loss of net photosynthetic rate was mitigated by N in medium O3 exposure (1.5 × AA). However, such a mitigation effect was not observed in the higher O3 level (2.0 × AA). Nitrogen addition exacerbated O3-induced increase of Rd suggesting an increased respiratory carbon loss in the presence of O3 and N. This may result in a further reduction of the net carbon gain for poplars exposed to O3.
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Affiliation(s)
- Lu Zhang
- College of Horticulture and Landscape Architecture, Northeast Agricultural University, Changjiang Road 600, Harbin, 150030, China
| | - Yasutomo Hoshika
- National Research Council of Italy, Via Madonna del Piano 10, 50019, Florence, Italy.
| | - Elisa Carrari
- National Research Council of Italy, Via Madonna del Piano 10, 50019, Florence, Italy
| | - Lorenzo Cotrozzi
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80, 56124, Pisa, Italy
| | - Elisa Pellegrini
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto, 80, 56124, Pisa, Italy
| | - Elena Paoletti
- National Research Council of Italy, Via Madonna del Piano 10, 50019, Florence, Italy
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Watanabe M, Hoshika Y, Inada N, Koike T. Photosynthetic activity in relation to a gradient of leaf nitrogen content within a canopy of Siebold's beech and Japanese oak saplings under elevated ozone. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 636:1455-1462. [PMID: 29913605 DOI: 10.1016/j.scitotenv.2018.04.423] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/24/2018] [Accepted: 04/30/2018] [Indexed: 06/08/2023]
Abstract
The primary objective of this study was to describe parameters related to the leaf biochemical assimilation capacity of photosynthesis, such as the maximum rates of carboxylation (Vcmax) and electron transport (Jmax), as a function of the leaf nitrogen content throughout a canopy of Siebold's beech and Japanese oak grown under elevated ozone (O3) conditions during a growing season. To this end, we investigated the relationship between photosynthetic traits and leaf nitrogen content in various canopy positions of two tree species under free-air O3 exposure (60 nmol mol-1, during daylight hours) in June, August, and October 2012. We observed O3-induced reduction in Vcmax and Jmax without reduction of leaf nitrogen content in both tree species. In Siebold's beech, Vcmax and Jmax in leaves with higher Narea were largely decreased by O3 from August, while little effect of O3 was observed in leaves with lower Narea. On the other hand, there was no difference in the extent of O3-induced reduction in Vcmax and Jmax across the range of Narea in leaves of Japanese oak. Reduction of leaf nitrogen content under elevated O3 conditions was observed only in Siebold's beech in October. These results indicated that the decrease in the efficiency of photosynthetic nitrogen use is in an earlier step in O3-induced decline of photosynthesis in Siebold's beech and Japanese oak. Based on these results, we emphasize the importance of integration of O3 effects into the conventional estimation of Vcmax and Jmax from leaf nitrogen content for evaluating canopy photosynthesis under current and future elevated O3 conditions.
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Affiliation(s)
- Makoto Watanabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Yasutomo Hoshika
- Institute of Sustainable Plant Protection, National Research Council of Italy, Via Madonna del Piano, I-50019 Sesto Fiorentino, Italy
| | - Naoki Inada
- Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo, Hokkaido 0608589, Japan
| | - Takayoshi Koike
- Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo, Hokkaido 0608589, Japan.
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8
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Kinose Y, Fukamachi Y, Okabe S, Hiroshima H, Watanabe M, Izuta T. Photosynthetic responses to ozone of upper and lower canopy leaves of Fagus crenata Blume seedlings grown under different soil nutrient conditions. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 223:213-222. [PMID: 28162800 DOI: 10.1016/j.envpol.2017.01.014] [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: 07/25/2016] [Revised: 01/09/2017] [Accepted: 01/09/2017] [Indexed: 06/06/2023]
Abstract
We aimed to clarify the effects of ozone (O3) on photosynthetic ability of upper and lower canopy leaves of Fagus crenata Blume seedlings grown under different soil nutrient conditions. To accomplish this objective, we analyzed the response of photosynthetic parameters such as maximum carboxylation rate (Vcmax) to cumulative stomatal O3 uptake (ΣFst) and reduction rate of Vcmax per unit ΣFst as an index of detoxification capacity for O3. The seedlings of Fagus crenata were grown for two growing seasons (2014-2015) in nine treatments comprised of a combination of three levels of gas treatments (charcoal-filtered air or 1.0- or 1.5-times ambient O3 concentration) and three levels of soil nutrient treatments (non-fertilized or a supply of relatively low or high concentrations of compound fertilizer). The nutrient supply significantly increased the degree of O3-induced reduction in Vcmax in September. However, nutrient supply did not significantly increase ΣFst and reduce the detoxification capacity for O3. On the other hand, the degree of O3-induced reduction in Vcmax of upper canopy leaves was higher as compared with that of lower canopy leaves in August due to the higher ΣFst. However, the reduction rate of Vcmax per unit ΣFst in lower canopy leaves was higher than that in upper canopy leaves, indicating lower detoxification capacity for O3 in lower canopy leaves. Reduction rate of Vcmax per unit ΣFst over the threshold, which is assumed to be proportional to gross photosynthetic rate, was similar between upper and lower canopy leaves. Therefore, capacity of photosynthetic CO2 assimilation is likely to be associated with detoxification capacity for O3 in upper and lower canopy leaves of F. crenata seedlings grown under different soil nutrient conditions.
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Affiliation(s)
- Yoshiyuki Kinose
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Yoshinobu Fukamachi
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Shigeaki Okabe
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Hiroka Hiroshima
- Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Makoto Watanabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Takeshi Izuta
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
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Watanabe M, Kitaoka S, Eguchi N, Watanabe Y, Satomura T, Takagi K, Satoh F, Koike T. Photosynthetic traits of Siebold's beech seedlings in changing light conditions by removal of shading trees under elevated CO₂. PLANT BIOLOGY (STUTTGART, GERMANY) 2016; 18 Suppl 1:56-62. [PMID: 26307372 DOI: 10.1111/plb.12382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 08/15/2015] [Indexed: 06/04/2023]
Abstract
The purpose of this study was to obtain basic information on acclimation capacity of photosynthesis in Siebold's beech seedlings to increasing light intensity under future elevated CO2 conditions. We monitored leaf photosynthetic traits of these seedlings in changing light conditions (before removal of shade trees, the year after removal of shade trees and after acclimation to open conditions) in a 10-year free air CO2 enrichment experiment in northern Japan. Elevated CO2 did not affect photosynthetic traits such as leaf mass per area, nitrogen content and biochemical photosynthetic capacity of chloroplasts (i.e. maximum rate of carboxylation and maximum rate of electron transport) before removal of the shade trees and after acclimation to open conditions; in fact, a higher net photosynthetic rate was maintained under elevated CO2 . However, in the year after removal of the shade trees, there was no increase in photosynthesis rate under elevated CO2 conditions. This was not due to photoinhibition. In ambient CO2 conditions, leaf mass per area and nitrogen content were higher in the year after removal of shade trees than before, whereas there was no increase under elevated CO2 conditions. These results indicate that elevated CO2 delays the acclimation of photosynthetic traits of Siebold's beech seedlings to increasing light intensity.
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Affiliation(s)
- M Watanabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, Japan
- Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo, Japan
| | - S Kitaoka
- Forestry and Forest Products Research Institute, Tsukuba, Japan
| | - N Eguchi
- Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo, Japan
| | - Y Watanabe
- Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo, Japan
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan
| | - T Satomura
- Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo, Japan
- Faculty of Agriculture, Kagawa University, Miki, Kagawa, Japan
| | - K Takagi
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan
| | - F Satoh
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Japan
| | - T Koike
- Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo, Japan
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Hoshika Y, Watanabe M, Kitao M, Häberle KH, Grams TEE, Koike T, Matyssek R. Ozone induces stomatal narrowing in European and Siebold's beeches: a comparison between two experiments of free-air ozone exposure. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2015; 196:527-33. [PMID: 25156633 DOI: 10.1016/j.envpol.2014.07.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 07/26/2014] [Accepted: 07/31/2014] [Indexed: 05/19/2023]
Abstract
Stomata tend to narrow under ozone (O(3)) impact, leading to limitation of stomatal O(3) influx. Here, we review stomatal response under recently conducted free-air O(3) exposure experiments on two species of the same tree genus: Fagus sylvatica at Kranzberg Forest (Germany) and F. crenata at Sapporo Experimental Forest (Japan). Both beeches exhibited reduction in stomatal conductance (gs) by 10-20% under experimentally enhanced O(3) regimes throughout the summer relative to ambient-air controls. Stomatal narrowing occurred, in early summer, in the absence of reduced carboxylation capacity of Rubisco, although photosynthetic net CO(2) uptake rate temporarily reflected restriction to some minor extent. Observed stomatal narrowing was, however, diminished in autumn, suggesting gradual loss of stomatal regulation by O(3). Monotonic decline in gs with cumulative O(3) exposure or flux in current modeling concepts appear to be unrealistic in beech.
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Affiliation(s)
- Yasutomo Hoshika
- Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo 060-8689, Japan.
| | - Makoto Watanabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu 183-8509, Japan
| | - Mitsutoshi Kitao
- Department of Plant Ecology, Forestry and Forest Products Research Institute, Tsukuba 305-8687, Japan
| | - Karl-Heinz Häberle
- Ecophysiology of Plants, Technische Universität München, Von-Carlowitz-Platz 2, D-85354 Freising, Germany
| | - Thorsten E E Grams
- Ecophysiology of Plants, Technische Universität München, Von-Carlowitz-Platz 2, D-85354 Freising, Germany
| | - Takayoshi Koike
- Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo 060-8689, Japan.
| | - Rainer Matyssek
- Ecophysiology of Plants, Technische Universität München, Von-Carlowitz-Platz 2, D-85354 Freising, Germany.
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Paoletti E, Castagna A, Ederli L, Pasqualini S, Ranieri A, Manning WJ. Gene expression in snapbeans exposed to ozone and protected by ethylenediurea. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 193:1-5. [PMID: 24975117 DOI: 10.1016/j.envpol.2014.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 05/29/2014] [Accepted: 06/03/2014] [Indexed: 06/03/2023]
Abstract
Ethylenediurea (EDU) is the most common chemical used to prevent ozone (O3) injury on vegetation. Despite considerable research, its mode of action remains elusive and gene expression has not been studied. Transcripts of major antioxidant enzymes (catalase, glutathione reductase, glutathione peroxidase) were measured for the first time in a model plant (Phaseolus vulgaris cv S156) after short-term O3 exposure (0 or 90 ppb, 5 h/d, 4 days) and a single spray with EDU (0 or 300 ppm). Visible, physiological and biochemical parameters were assessed as indices of O3-induced stress. In O3-exposed EDU-protected plants, levels of transcript, enzyme activity, H2O2 accumulation, gas exchange and foliar visible injury were similar to those in control plants. These results suggest that EDU may halt the O3-induced ROS generation within 24 h from the exposure, and thus the downstream cascade mechanisms leading to increased H2O2 production, impaired gas exchange, and occurrence of leaf lesions.
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Affiliation(s)
- E Paoletti
- Institute of Sustainable Plant Protection, National Council of Research, Via Madonna del Piano 10, 50019, Sesto Fiorentino, Firenze, Italy.
| | - A Castagna
- Department of Agricultural, Ambient and Agro-Food Sciences, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
| | - L Ederli
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Borgo XX Giugno 74, I-06121 Perugia, Italy
| | - S Pasqualini
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Borgo XX Giugno 74, I-06121 Perugia, Italy
| | - A Ranieri
- Department of Agricultural, Ambient and Agro-Food Sciences, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
| | - W J Manning
- Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA, USA
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Hoshika Y, Watanabe M, Inada N, Koike T. Model-based analysis of avoidance of ozone stress by stomatal closure in Siebold's beech (Fagus crenata). ANNALS OF BOTANY 2013; 112:1149-58. [PMID: 23904447 PMCID: PMC3783231 DOI: 10.1093/aob/mct166] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 06/04/2013] [Indexed: 05/13/2023]
Abstract
BACKGROUND AND AIMS Resistance of plants to ozone stress can be classified as either avoidance or tolerance. Avoidance of ozone stress may be explained by decreased stomatal conductance during ozone exposure because stomata are the principal interface for entry of ozone into plants. In this study, a coupled photosynthesis-stomatal model was modified to test whether the presence of ozone can induce avoidance of ozone stress by stomatal closure. METHODS The response of Siebold's beech (Fagus crenata), a representative deciduous tree species, to ozone was studied in a free-air ozone exposure experiment in Japan. Photosynthesis and stomatal conductance were measured under ambient and elevated ozone. An optimization model of stomata involving water, CO2 and ozone flux was tested using the leaf gas exchange data. KEY RESULTS The data suggest that there are two phases in the avoidance of ozone stress via stomatal closure for Siebold's beech: (1) in early summer ozone influx is efficiently limited by a reduction in stomatal conductance, without any clear effect on photosynthetic capacity; and (2) in late summer and autumn the efficiency of ozone stress avoidance was decreased because the decrease in stomatal conductance was small and accompanied by an ozone-induced decline of photosynthetic capacity. CONCLUSIONS Ozone-induced stomatal closure in Siebold's beech during early summer reduces ozone influx and allows the maximum photosynthetic capacity to be reached, but is not sufficient in older leaves to protect the photosynthetic system.
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Affiliation(s)
| | | | | | - Takayoshi Koike
- Silviculture and Forest Ecological Studies, Hokkaido University, Sapporo 060-8689, Japan
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