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Joffe R, Tosens T, Berthe A, Jolivet Y, Niinemets Ü, Gandin A. Reduced mesophyll conductance under chronic O 3 exposure in poplar reflects thicker cell walls and increased subcellular diffusion pathway lengths according to the anatomical model. PLANT, CELL & ENVIRONMENT 2024. [PMID: 39101376 DOI: 10.1111/pce.15049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 06/23/2024] [Accepted: 07/04/2024] [Indexed: 08/06/2024]
Abstract
Ozone (O3) is one of the most harmful and widespread air pollutants, affecting crop yield and plant health worldwide. There is evidence that O3 reduces the major limiting factor of photosynthesis, namely CO2 mesophyll conductance (gm), but there is little quantitative information of O3-caused changes in key leaf anatomical traits and their impact on gm. We exposed two O3-responsive clones of the economically important tree species Populus × canadensis Moench to 120 ppb O3 for 21 days. An anatomical diffusion model within the leaf was used to analyse the entire CO2 diffusion pathway from substomatal cavities to carboxylation sites and determine the importance of each structural and subcellular component as a limiting factor. gm decreased substantially under O3 and was found to be the most important limitation of photosynthesis. This decrease was mostly driven by an increased cell wall thickness and length of subcellular diffusion pathway caused by altered interchloroplast spacing and chloroplast positioning. By contrast, the prominent leaf integrative trait leaf dry mass per area was neither affected nor related to gm under O3. The observed relationship between gm and anatomy, however, was clone-dependent, suggesting that mechanisms regulating gm may differ considerably between closely related plant lines. Our results confirm the need for further studies on factors constraining gm under stress conditions.
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Affiliation(s)
- Ricardo Joffe
- Faculté des Sciences et Technologies, Université de Lorraine, AgroParisTech, INRAE, SILVA, Nancy, France
| | - Tiina Tosens
- Department of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia
| | - Audrey Berthe
- Faculté des Sciences et Technologies, Université de Lorraine, AgroParisTech, INRAE, SILVA, Nancy, France
| | - Yves Jolivet
- Faculté des Sciences et Technologies, Université de Lorraine, AgroParisTech, INRAE, SILVA, Nancy, France
| | - Ülo Niinemets
- Department of Crop Science and Plant Biology, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, Estonia
- Estonian Academy of Sciences, Tallinn, Estonia
| | - Anthony Gandin
- Faculté des Sciences et Technologies, Université de Lorraine, AgroParisTech, INRAE, SILVA, Nancy, France
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Wu T, Song Y, Tissue D, Su W, Luo H, Li X, Yang S, Liu X, Yan J, Huang J, Liu J. Photosynthetic and biochemical responses of four subtropical tree seedlings to reduced dry season and increased wet season precipitation and variable N deposition. TREE PHYSIOLOGY 2024; 44:tpad114. [PMID: 37756634 DOI: 10.1093/treephys/tpad114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 06/27/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023]
Abstract
Interspecific variations in phenotypic plasticity of trees that are affected by climate change may alter the ecosystem function of forests. Seedlings of four common tree species (Castanopsis fissa, Michelia macclurei, Dalbergia odorifera and Ormosia pinnata) in subtropical plantations of southern China were grown in the field under rainout shelters and subjected to changing precipitation (48 L of water every 4 days in the dry season, 83 L of water every 1 day in the wet season; 4 g m-2 year-1 of nitrogen (N)), low N deposition (48 L of water every 2 days in the dry season, 71 L of water every 1 day in the wet season; 8 g m-2 year-1 N), high N deposition (48 L of water every 2 days in the dry season, 71 L of water every 1 day in the wet season; 10 g m-2 year-1 N) and their interactive effects. We found that the changes in seasonal precipitation reduced the light-saturated photosynthetic rate (Asat) for C. fissa due to declining area-based foliar N concentrations (Na). However, we also found that the interactive effects of changing precipitation and N deposition enhanced Asat for C. fissa by increasing foliar Na concentrations, suggesting that N deposition could alleviate N limitations associated with changing precipitation. Altered precipitation and high N deposition reduced Asat for D. odorifera by decreasing the maximum electron transport rate for RuBP regeneration (Jmax) and maximum rate of carboxylation of Rubisco (Vcmax). Ormosia pinnata under high N deposition exhibited increasing Asat due to higher stomatal conductance and Vcmax. The growth of D. odorifera might be inhibited by changes in seasonal precipitation and N deposition, while O. pinnata may benefit from increasing N deposition in future climates. Our study provides an important insight into the selection of tree species with high capacity to tolerate changing precipitation and N deposition in subtropical plantations.
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Affiliation(s)
- Ting Wu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW 2751, Australia
- Global Centre for Land-Based Innovation, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW 2751, Australia
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Yuting Song
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - David Tissue
- Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW 2751, Australia
- Global Centre for Land-Based Innovation, Western Sydney University, Hawkesbury Campus, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Wei Su
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Hanyu Luo
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Xu Li
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Shimin Yang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Xujun Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Junhua Yan
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China
| | - Juan Huang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China
| | - Juxiu Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China
- Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, 723 Xingke Road, Tianhe District, Guangzhou 510650, China
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Sahoo A, Madheshiya P, Mishra AK, Tiwari S. Combating ozone stress through N fertilization: A case study of Indian bean ( Dolichos lablab L.). FRONTIERS IN PLANT SCIENCE 2023; 14:1125529. [PMID: 36909422 PMCID: PMC9992209 DOI: 10.3389/fpls.2023.1125529] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/07/2023] [Indexed: 05/31/2023]
Abstract
The present study investigates the efficiency of nitrogen (N) amendments in the management of ozone (O3) stress in two varieties (Kashi Sheetal and Kashi Harittima) of Indian bean (Dolichos lablab L.). Two O3 concentrations, ambient (44.9 ppb) and elevated (74.64 ppb) were used, and each O3 concentration has 3 nitrogen (N) dose treatments viz recommended (N1), 1.5 times recommended (N2), 2 times recommended (N3) and no nitrogen, which served as control (C). The experiment concluded Kashi Sheetal as O3 tolerant, as compared to Kashi Harittima. N amendments were effective in the partial amelioration of O3 stress, with N2 being the most effective nitrogen dose, at both ambient and elevated O3 concentrations. Kashi Sheetal has been determined to be O3 tolerant due to greater endogenous levels of H2O2 accumulation and enzymatic antioxidant contents with O3 exposure. The O3-sensitive variety, Kashi Harittima, responded more positively to N treatments, at both O3 concentrations. The positive effect of N amendments is attributed to the stimulated antioxidative enzyme activity, rather than the biophysical processes like stomatal conductance. Strengthened defense upon N amendments was attributed to the enhanced activities of APX and GR in Kashi Sheetal, while in Kashi Harittima, the two enzymes (APX and GR) were coupled by SOD and CAT as well, during the reproductive phase. Yield (weight of seeds plant-1) increments upon N (N2) amendments were higher in Kashi Harittima (O3 sensitive), as compared to Kashi Sheetal (O3 tolerant) at both ambient and elevated O3 concentration, due to higher antioxidant enzymatic response and greater rate of photosynthesis in the former.
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Joffe R, Berthe A, Jolivet Y, Gandin A. The response of mesophyll conductance to ozone-induced oxidative stress is genotype-dependent in poplar. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4850-4866. [PMID: 35429268 DOI: 10.1093/jxb/erac154] [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: 10/06/2021] [Accepted: 04/14/2022] [Indexed: 06/14/2023]
Abstract
The CO2 diffusion conductance within the leaf mesophyll (gm) is considered a major limiting factor of photosynthesis. However, the effects of the major secondary air pollutant ozone (O3) on gm have been poorly investigated. Eight genotypes of the economically important tree species Populus × canadensis Moench were exposed to 120 ppb O3 for 21 d. gm showed a genotype-dependent response to O3-induced oxidative stress and was a major limiting factor of net assimilation rate (Anet), ahead of stomatal conductance to CO2 (gsc) and of the maximum carboxylation capacity of the Rubisco enzyme (Vcmax) in half of the tested genotypes. Increased leaf dry mass per area (LMA) and decreased chlorophyll content were linked to the observed gm decrease, but this relationship did not entirely explain the different genotypic gm responses. Moreover, the oxidative stress defence metabolites ascorbate and glutathione were not related to O3 tolerance of gm. However, malondialdehyde probably mitigated the observed gm decrease in some genotypes due to its oxidative stress signalling function. The large variation of gm suggests different regulation mechanisms amongst poplar genotypes under oxidative stress.
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Affiliation(s)
- Ricardo Joffe
- Université de Lorraine, AgroParisTech, INRAE, SILVA, F-54000 Nancy, France
| | - Audrey Berthe
- Université de Lorraine, AgroParisTech, INRAE, SILVA, F-54000 Nancy, France
| | - Yves Jolivet
- Université de Lorraine, AgroParisTech, INRAE, SILVA, F-54000 Nancy, France
| | - Anthony Gandin
- Université de Lorraine, AgroParisTech, INRAE, SILVA, F-54000 Nancy, France
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Watanabe M, Li J, Matsumoto M, Aoki T, Ariura R, Fuse T, Zhang Y, Kinose Y, Yamaguchi M, Izuta T. Growth and photosynthetic responses to ozone of Siebold's beech seedlings grown under elevated CO 2 and soil nitrogen supply. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 304:119233. [PMID: 35358628 DOI: 10.1016/j.envpol.2022.119233] [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: 12/14/2021] [Revised: 03/06/2022] [Accepted: 03/27/2022] [Indexed: 06/14/2023]
Abstract
Ozone (O3) is a phytotoxic air pollutant, the adverse effects of which on growth and photosynthesis are modified by other environmental factors. In this study, we examined the combined effects of O3, elevated CO2, and soil nitrogen supply on Siebold's beech seedlings. Seedlings were grown under combinations of two levels of O3 (low and two times ambient O3 concentration), two levels of CO2 (ambient and 700 ppm), and three levels of soil nitrogen supply (0, 50, and 100 kg N ha-1 year-1) during two growing seasons (2019 and 2020), with leaf photosynthetic traits being determined during the second season. We found that elevated CO2 ameliorated O3-induced reductions in photosynthetic activity, whereas the negative effects of O3 on photosynthetic traits were enhanced by soil nitrogen supply. We observed three-factor interactions in photosynthetic traits, with the ameliorative effects of elevated CO2 on O3-induced reductions in the maximum rate of carboxylation being more pronounced under high than under low soil nitrogen conditions in July. In contrast, elevated CO2-induced amelioration of the effects of O3 on stomatal function-related traits was more pronounced under low soil nitrogen conditions. Although we observed several two- or three-factor interactions of gas and soil treatments with respect to leaf photosynthetic traits, the shoot to root dry mass (S/R) ratio was the only parameter for which a significant interaction was detected among seedling growth parameters. O3 caused a significant increase in S/R under ambient CO2 conditions, whereas no similar effects were observed under elevated CO2 conditions. Collectively, our findings reveal the complex interactive effects of elevated CO2 and soil nitrogen supply on the detrimental effects of O3 on leaf photosynthetic traits, and highlight the importance of taking into consideration differences between the responses of CO2 uptake and growth to these three environmental factors.
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Affiliation(s)
- Makoto Watanabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Jing Li
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Misako Matsumoto
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Takuro Aoki
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Ryo Ariura
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Tsuyoshi Fuse
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Yazhuo Zhang
- Graduate School of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan
| | - Yoshiyuki Kinose
- Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Kofu, Yamanashi 400-8510, Japan
| | - Masahiro Yamaguchi
- Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852-8521, Japan
| | - Takeshi Izuta
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
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Responses of Growth, Oxidative Injury and Chloroplast Ultrastructure in Leaves of Lolium perenne and Festuca arundinacea to Elevated O 3 Concentrations. Int J Mol Sci 2022; 23:ijms23095153. [PMID: 35563542 PMCID: PMC9104282 DOI: 10.3390/ijms23095153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/30/2022] [Accepted: 05/01/2022] [Indexed: 11/26/2022] Open
Abstract
The effects of increasing atmospheric ozone (O3) concentrations on cool-season plant species have been well studied, but little is known about the physiological responses of cool-season turfgrass species such as Lolium perenne and Festuca arundinacea exposed to short-term acute pollution with elevated O3 concentrations (80 ppb and 160 ppb, 9 h d−1) for 14 days, which are widely planted in urban areas of Northern China. The current study aimed to investigate and compare O3 sensitivity and differential changes in growth, oxidative injury, antioxidative enzyme activities, and chloroplast ultrastructure between the two turf-type plant species. The results showed that O3 decreased significantly biomass regardless of plant species. Under 160 ppb O3, total biomass of L. perenne and F. arundinacea significantly decreased by 55.3% and 47.8% (p < 0.05), respectively. No significant changes were found in visible injury and photosynthetic pigment contents in leaves of the two grass species exposed to 80 ppb O3, except for 160 ppb O3. However, both 80 ppb and 160 ppb O3 exposure induced heavily oxidative stress by high accumulation of malondialdehyde and reactive oxygen species in leaves and damage in chloroplast ultrastructure regardless of plant species. Elevated O3 concentration (80 ppb) increased significantly the activities of superoxide dismutase, catalase and peroxidaseby 77.8%, 1.14-foil and 34.3% in L. perenne leaves, and 19.2%, 78.4% and 1.72-fold in F. arundinacea leaves, respectively. These results showed that F. arundinacea showed higher O3 tolerance than L. perenne. The damage extent by elevated O3 concentrations could be underestimated only by evaluating foliar injury or chlorophyll content without considering the internal physiological changes, especially in chloroplast ultrastructure and ROS accumulation.
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Braun S, Rihm B, Schindler C. Epidemiological Estimate of Growth Reduction by Ozone in Fagus sylvatica L. and Picea abies Karst.: Sensitivity Analysis and Comparison with Experimental Results. PLANTS (BASEL, SWITZERLAND) 2022; 11:777. [PMID: 35336659 PMCID: PMC8954156 DOI: 10.3390/plants11060777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
The critical level of ozone flux for forest trees is based entirely on biomass data from fumigation experiments with saplings, mostly in open-top chambers. Extrapolation to mature forests asks, therefore, for validation, which may be performed by epidemiological data analysis. This requires a multivariable regression analysis with a number of covariates to account for potential confounding factors. The present paper analyses the ozone sensitivity of volume increments of mature European beech (Fagus sylvatica) and Norway spruce (Picea abies), with the addition, or removal, of covariates. The comparison of the epidemiological dose-response relationship with experimental data shows very good agreement in beech and a more sensitive relationship in the epidemiological analysis of Norway spruce compared to the experiments. In Norway spruce, there was also a strong interaction between the effects of ozone and temperature; at high July temperatures, the ozone effect was stronger. This interaction may explain the disagreement between the epidemiological study and the experiments, of which the majority were performed in Sweden.
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Affiliation(s)
- Sabine Braun
- Institute for Applied Plant Biology AG, CH-4108 Witterswil, Switzerland
| | - Beat Rihm
- Meteotest AG, CH-3014 Berne, Switzerland;
| | - Christian Schindler
- Swiss Tropical and Public Health Institute, University of Basel, CH-4002 Basel, Switzerland;
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Xu Y, Feng Z, Kobayashi K. Performances of a system for free-air ozone concentration elevation with poplar plantation under increased nitrogen deposition. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:58298-58309. [PMID: 34115305 DOI: 10.1007/s11356-021-14639-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 05/26/2021] [Indexed: 06/12/2023]
Abstract
The increasing emission of nitrogen oxides exerts large impacts on vegetation by raising surface ozone (O3) concentrations and enhancing atmospheric nitrogen (N) deposition. We established a free-air O3 concentration elevation and enhanced N deposition system (O3-N-FACE) in Beijing, China, to investigate long-term effects of elevated O3 and N deposition on poplar plantation. Eight square plots with a side length of 16 m were randomly allocated to elevated O3 (E-O3) and ambient air (AA) treatments. Ozone generated by electric discharge in pure oxygen is mixed with clean and dry air, and released from small holes on the tubes installed above the plant canopy at a rate controlled to keep O3 concentration in E-O3 plots by 50% higher than that in AA plots. Each O3 treatment plot consisted of four subplots with a factorial combination of 2 lines of poplar clones and 2 levels of N deposition rate. In enhanced N deposition subplots, we sprayed urea solution on the plantation floor at a rate of 60 kg ha-1 year-1. We hereby present the system performances during the growing seasons of 2018 and 2019: the first 2 years of experiment. The mean daytime O3 concentrations of E-O3 plots were 38% and 31% higher than AA plots in 2018 and 2019, respectively. And, in 2019, the accumulated O3 exposure over 40 ppb (AOT40) in E-O3 plots was 70% higher than that in AA plots. The hourly mean O3 concentrations in E-O3 plots were within 20% of the target for 83% of time on average across the four E-O3 plots. Within the E-O3 plots, spatial distribution of the hourly O3 concentration exhibited the maximum deviation at 24% in 2019. We concluded that performance of this system is better than other similar facilities for trees and suitable for a long-term experiment of enhanced O3 and N.
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Affiliation(s)
- Yansen Xu
- School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, 210044, China
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Zhaozhong Feng
- School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, 210044, China.
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
| | - Kazuhiko Kobayashi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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Peng J, Xu Y, Shang B, Agathokleous E, Feng Z. Effects of elevated ozone on maize under varying soil nitrogen levels: Biomass, nitrogen and carbon, and their allocation to kernel. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 765:144332. [PMID: 33385814 DOI: 10.1016/j.scitotenv.2020.144332] [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: 10/29/2020] [Revised: 12/04/2020] [Accepted: 12/04/2020] [Indexed: 06/12/2023]
Abstract
Effects of ozone (O3) on maize have been increasingly studied, but only few studies have focused on the combined impacts of O3 and nitrogen (N) on this important crop with C4 carbon (C) fixation. In this study, a maize cultivar with the largest acreage in China was exposed to two O3 treatments (NF: ambient air O3 concentration; NF60: NF plus 60 ppb O3) and four N levels (farmers' N practice: 240 kg N ha-1 yr-1; 150%, 50% and 25% of farmers' N practice). Generally, O3 and N significantly influenced biomass, N and C, but did not change their allocation to kernel. There were significant interactions between O3 and N in stem biomass, C concentration and uptake, and leaf biomass and C uptake, with significant O3 effects mainly occurring at N120 and N240. Based on the coefficient of determination (R2), root C:N ratio rather than the most commonly used leaf C:N ratio was the best trait to indicate maize productivity. Furthermore, O3 significantly increased the regression slopes between root C:N ratio and kernel N uptake, kernel C uptake and plant N uptake, strengthened the correlation of C:N ratio and kernel C uptake, and weakened the correlation of C:N ratio and hundred-kernels weight. These suggest that O3 pollution can change the relationship of C:N ratio and productivity in maize. The weak correlation between kernel harvest index (HI) and N harvest index (NHI) indicated that future breeding researches should consider how to improve the coupling between biomass and N-related nutrition allocations in crop edible parts. Our results not only are helpful to accurately estimate O3 impacts on maize with consideration of N but also provide a new insight into the relationship between plant traits and its productivity under O3 pollution.
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Affiliation(s)
- Jinlong Peng
- Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yansen Xu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bo Shang
- Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Evgenios Agathokleous
- Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Zhaozhong Feng
- Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
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Sen Gupta G, Tiwari S. Role of antioxidant pool in management of ozone stress through soil nitrogen amendments in two cultivars of a tropical legume. FUNCTIONAL PLANT BIOLOGY : FPB 2021; 48:371-385. [PMID: 33256894 DOI: 10.1071/fp20159] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 10/14/2020] [Indexed: 06/12/2023]
Abstract
The present experiment was done on two different cultivars of a tropical legume, Cymopsis tetragonoloba L. Taub. (cluster bean) cvv. Pusa-Naubahar (PUSA-N) and Selection-151 (S-151). The experiment was conducted under ambient ozone (O3) conditions with inputs of three different doses of inorganic nitrogen (N1, recommended; N2, 1.5-times recommended and N3, 2-times recommended) as well as control plants. The objective of this study was to evaluate the effectiveness of soil nitrogen amendments in management of ambient ozone stress in the two cultivars of C. tetragonoloba. Our experiment showed that nitrogen amendments can be an efficient measure to manage O3 injury in plants. Stimulation of antioxidant enzyme activities under nitrogen amendments is an important feature of plants that help plants cope with ambient O3 stress. Nitrogen amendments strengthened the antioxidant machinery in a more effective way in the tolerant cultivar PUSA-N, while in the sensitive cultivar S-151, avoidance strategy marked by more reduction in stomatal conductance was more prominent. Enzymes of the Halliwell-Asada pathway, especially ascorbate peroxidase and glutathione reductase, were more responsive and synchronised in PUSA-N than S-151, under similar nitrogen amendment regimes and were responsible for the differential sensitivities of the two cultivars of C. tetragonoloba. The present study shows that 1.5-times recommended dose of soil nitrogen amendments was sufficient in partial mitigation of O3 injury and the higher nitrogen dose (2-times recommended, in our case), did not provide any extra advantage to the plant's metabolism compared with plants treated with the lower nitrogen dose (1.5-times recommended).
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Affiliation(s)
- Gereraj Sen Gupta
- Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, India
| | - Supriya Tiwari
- Department of Botany, Institute of Science, Banaras Hindu University, Varanasi, India; and Corresponding author.
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11
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Shang B, Xu Y, Peng J, Agathokleous E, Feng Z. High nitrogen addition decreases the ozone flux by reducing the maximum stomatal conductance in poplar saplings. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 272:115979. [PMID: 33168377 DOI: 10.1016/j.envpol.2020.115979] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/24/2020] [Accepted: 10/30/2020] [Indexed: 06/11/2023]
Abstract
Ground-level ozone (O3) and nitrogen (N) deposition are major environmental pollutants, often occurring concurrently. Ozone exposure- and flux-response relationships for tree biomass are used for regional O3 risk assessment. In order to investigate whether soil N addition affects stomatal O3 uptake of poplar, poplar saplings were exposed to treatment combinations of five O3 levels and four N addition levels. High N addition treatment reduced the accumulated stomatal O3 uptake in the leaf due to reduced maximum stomatal conductance (gs). Nitrogen addition also significantly reduced the steady-state light-saturated gs in August and September. Elevated O3 significantly reduced and N addition increased total plant biomass; however, there were no significant O3 × N interactions. The slopes of biomass-based O3 exposure- and flux-response relationships did not differ significantly among N treatments. The critical levels for a 5% biomass reduction were estimated at 15.4 ppm h and 17.1 mmol O3 m-2 projected leaf area (PLA) for Accumulated O3 exposure Over an hourly Threshold of 40 ppb (AOT40) and Phytotoxic Ozone Dose above a threshold 1 nmol O3 m-2 PLA s-1 (POD1). These results can facilitate the evaluations of O3 effect on the carbon-sink capacity and productivity of forest.
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Affiliation(s)
- Bo Shang
- Key Laboratory of Agrometeorology of Jiangsu Province, Institute of Ecology, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Yansen Xu
- Key Laboratory of Agrometeorology of Jiangsu Province, Institute of Ecology, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, 210044, China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China
| | - Jinlong Peng
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China
| | - 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
| | - Zhaozhong Feng
- Key Laboratory of Agrometeorology of Jiangsu Province, Institute of Ecology, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing, 210044, China.
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12
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Wang Q, Li Z, Li X, Ping Q, Yuan X, Agathokleous E, Feng Z. Interactive effects of ozone exposure and nitrogen addition on the rhizosphere bacterial community of poplar saplings. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:142134. [PMID: 33254895 DOI: 10.1016/j.scitotenv.2020.142134] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 06/12/2023]
Abstract
It is widely documented that elevated ground-level ozone (O3) has negative effects on tree physiological characteristics, and in return, affects forest ecosystem function. However, the effect may be modified by soil nitrogen (N) availability. Numerous studies have focused on the aboveground part of trees under elevated O3 alone or in combination with soil N; however, little is known about the response of soil bacterial communities. Here, we investigated the effects of O3 (charcoal-filtered air, CF, versus ambient air +40 ppb of O3, E-O3), N addition (0 kg ha-1 yr-1, N0, versus 200 kg ha-1 yr-1, N200), and their combination on rhizosphere soil bacterial communities of hybrid poplar, using an MiSeq targeted amplicon sequencing of the bacterial 16S rRNA gene. E-O3 significantly decreased bacterial abundance, and N200 significantly decreased the α-diversity. The negative impacts of N200 on α-diversity were alleviated by E-O3. Nitrogen and E-O3-N200 combination altered bacterial community composition, with a significant increase in the relative abundance of Proteobacteria and Bacteroidetes and a decrease in the abundance of Firmicutes. From an ecological network analysis, E-O3, alone and in combination with N200, complicated the co-occurrence network of bacterial communities by inducing a microbial survival strategy, shifting the hub species from RB41 to Bacillus and Blastococcus. Conversely, N200 led to simplification and decentralization of the co-occurrence network. These findings demonstrate that the rhizosphere bacterial communities exhibit divergent responses to E-O3 and N200, suggesting the need to consider the stability of the belowground ecosystem to optimize plantation management in response to environmental changes.
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Affiliation(s)
- Qi Wang
- Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Zhengzhen Li
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China
| | - Xuewei Li
- Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Qin Ping
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China
| | - Xiangyang Yuan
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China
| | - Evgenios Agathokleous
- Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Zhaozhong Feng
- Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
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13
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Kumar S, Peterson TR. Moonshots for aging. ACTA ACUST UNITED AC 2020; 5:239-246. [PMID: 33344796 PMCID: PMC7740370 DOI: 10.3233/nha-190064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
As the global population ages, there is increased interest in living longer and improving one’s quality of life in later years. However, studying aging – the decline in body function – is expensive and time-consuming. And despite research success to make model organisms live longer, there still aren’t really any feasible solutions for delaying aging in humans. With space travel, scientists and engineers couldn’t know what it would take to get to the moon. They had to extrapolate from theory and shorter-range tests. Perhaps with aging, we need a similar moonshot philosophy. And though “shot” might imply medicine, perhaps we need to think beyond medical interventions. Like the moon once was, we seem a long way away from provable therapies to increase human healthspan (the healthy period of one’s life) or lifespan (how long one lives). This review therefore focuses on radical proposals. We hope it might stimulate discussion on what we might consider doing significantly differently than ongoing aging research.
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Affiliation(s)
- Sandeep Kumar
- Department of Internal Medicine, Division of Bone and Mineral Diseases, Department of Genetics, Institute for Public Health, Washington University School of Medicine, BJC Institute of Health, MO, USA
| | - Timothy R Peterson
- Department of Internal Medicine, Division of Bone and Mineral Diseases, Department of Genetics, Institute for Public Health, Washington University School of Medicine, BJC Institute of Health, MO, USA
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14
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Yuan X, Li S, Feng Z, Xu Y, Shang B, Fares S, Paoletti E. Response of isoprene emission from poplar saplings to ozone pollution and nitrogen deposition depends on leaf position along the vertical canopy profile. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:114909. [PMID: 32540567 DOI: 10.1016/j.envpol.2020.114909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/25/2020] [Accepted: 05/28/2020] [Indexed: 06/11/2023]
Abstract
We investigated isoprene (ISO) emission and gas exchange in leaves from different positions along the vertical canopy profile of poplar saplings (Populus euramericana cv. '74/76'). For a growing season, plants were subjected to four N treatments, control (NC, no N addition), low N (LN, 50 kg N ha-1year-1), middle N (MN, 100 kg N ha-1year-1), high N (HN, 200 kg N ha-1year-1) and three O3 treatments (CF, charcoal-filtered ambient air; NF, non-filtered ambient air; NF + O3, NF + 40 ppb O3). Our results showed the effects of O3 and/or N on standardized ISO rate (ISOrate) and photosynthetic parameters differed along with the leaf position, with larger negative effects of O3 and positive effects of N on ISOrate and photosynthetic parameters in the older leaves. Expanded young leaves were insensitive to both treatments even at very high O3 concentration (67 ppb as 10-h average) and HN treatment. Significant O3 × N interactions were only found in middle and lower leaves, where ISOrate declined by O3 just when N was limited (NC and LN). With increasing light-saturated photosynthesis and chlorophyll content, ISOrate was reduced in the upper leaves but on the contrary increased in middle and lower leaves. The responses of ISOrate to AOT40 (accumulated exposure to hourly O3 concentrations > 40 ppb) and PODY (accumulative stomatal uptake of O3 > Y nmol O3 m-2 PLA s-1) were not significant in upper leaves, but ISOrate significantly decreased with increasing AOT40 or PODY under limited N supply in middle leaves but at all N levels in lower leaves. Overall, ISOrate changed along the vertical canopy profile in response to combined O3 and N exposure, a behavior that should be incorporated into multi-layer canopy models. Our results are relevant for modelling regional isoprene emissions under current and future O3 pollution and N deposition scenarios.
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Affiliation(s)
- Xiangyang Yuan
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China
| | - Shuangjiang Li
- School of Applied Meteorology, Nanjing University of Information Science & Technology, 219 Ningliu Road, Nanjing, 210044, China
| | - Zhaozhong Feng
- School of Applied Meteorology, Nanjing University of Information Science & Technology, 219 Ningliu Road, Nanjing, 210044, China; National Engineering Laboratory for VOCs Pollution Control Material & Technology, University of Chinese Academy of Sciences, Beijing, 101408, China.
| | - Yansen Xu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China
| | - Bo Shang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China
| | - Silvano Fares
- Council for Agricultural Research and Economics (CREA) - Research Centre for Forestry and Wood, Via Valle della Quistione 27, 00166, Rome, Italy
| | - Elena Paoletti
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China; Institute of Research on Terrestrial Ecosystems, National Research Council, via Madonna del Piano 10, 50019 Sesto Fiorentino, Italy
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15
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Xu Y, Shang B, Feng Z, Tarvainen L. Effect of elevated ozone, nitrogen availability and mesophyll conductance on the temperature responses of leaf photosynthetic parameters in poplar. TREE PHYSIOLOGY 2020; 40:484-497. [PMID: 32031641 DOI: 10.1093/treephys/tpaa007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 12/09/2019] [Accepted: 01/13/2020] [Indexed: 06/10/2023]
Abstract
Although ozone (O3) concentration and nitrogen (N) availability are well known to affect plant physiology, their impacts on the photosynthetic temperature response are poorly understood. We addressed this knowledge gap by exposing seedlings of hybrid poplar clone '107' (Populous euramericana cv. '74/76') to elevated O3 (E-O3) and N availability variation in a factorial experiment. E-O3 decreased light-saturated net photosynthesis (Asat), mesophyll conductance (gm) and apparent maximum rate of carboxylation (Vcmax, based on intercellular CO2 concentration) but not actual Vcmax (based on chloroplast CO2 concentration) and increased respiration in light (Rd) at 25 °C. Nitrogen fertilization increased Asat, gm, Vcmax and the maximum rate of electron transport (Jmax) and reduced Rd at 25 °C and the activation energy of actual Vcmax. No E-O3 or E-O3 x N interaction effects on the temperature response parameters were detected, simplifying the inclusion of O3 impacts on photosynthesis in vegetation models. gm peaked at 30 °C, apparent Vcmax and Jmax at 32-33 °C, while the optimum temperatures of actual Vcmax and Jmax exceeded the measured temperature range (15-35 °C). Ignoring gm would, thus, have resulted in mistakenly attributing the decrease in Asat at high temperatures to reduced biochemical capacity rather than to greater diffusion limitation.
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Affiliation(s)
- Yansen Xu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bo Shang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaozhong Feng
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Ecology, Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Lasse Tarvainen
- Department of Biological and Environmental Sciences, University of Gothenburg, 405 30 Gothenburg, Sweden
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16
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Li P, Yin R, Shang B, Agathokleous E, Zhou H, Feng Z. Interactive effects of ozone exposure and nitrogen addition on tree root traits and biomass allocation pattern: An experimental case study and a literature meta-analysis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 710:136379. [PMID: 31926420 DOI: 10.1016/j.scitotenv.2019.136379] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 11/13/2019] [Accepted: 12/26/2019] [Indexed: 06/10/2023]
Abstract
Ground-level ozone (O3) pollution often co-occurs with anthropogenic nitrogen (N) deposition. Many studies have explored how O3 and soil N affect aboveground structure and function of trees, but it remains unclear how belowground processes change over a spectrum of N addition and O3 concentrations levels. Here, we explored the interactive impact of O3 (five levels) and soil N (four levels) on fine and coarse root biomass and biomass allocation pattern in poplar clone 107 (Populus euramericana cv. '74/76'). We then evaluated the modifying effects of N on the responses of tree root biomass to O3 via a synthesis of published literature. Elevated O3 inhibited while N addition stimulated root biomass, with more pronounced effects on fine roots than on coarse root. The root:shoot (R:S) ratio was markedly decreased by N addition but remained unaffected by O3. No interactive effects between O3 and N were observed on root biomass and R:S ratio. The slope of log-log linear relationship between shoot and root biomass (i.e. scaling exponent) was increased by N, but not significantly affected by O3. The analysis of published literature further revealed that the O3-induced reduction in tree root biomass was not modified by soil N. The results suggest that higher N addition levels enhance faster allocation of shoot biomass while shoot biomass scales isometrically with root biomass across multiple O3 levels. N addition does not markedly alter the sensitivity of root biomass of trees to O3. These findings highlight that the biomass allocation exhibits a differential response to environmentally realistic levels of O3 and N, and provide an important perspective for understanding and predicting net primary productivity and carbon dynamics in O3-polluted and N-enriched environments.
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Affiliation(s)
- Pin Li
- College of Forestry, Beijing Forestry University, Beijing 100083, China; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China
| | - Rongbin Yin
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China
| | - Bo Shang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China
| | - 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
| | - Huimin Zhou
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, 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.
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Hayes F, Lloyd B, Mills G, Jones L, Dore AJ, Carnell E, Vieno M, Dise N, Fenner N. Impact of long-term nitrogen deposition on the response of dune grassland ecosystems to elevated summer ozone. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 253:821-830. [PMID: 31344543 DOI: 10.1016/j.envpol.2019.07.088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 07/04/2019] [Accepted: 07/17/2019] [Indexed: 06/10/2023]
Abstract
Nitrogen deposition and tropospheric ozone are important drivers of vegetation damage, but their interactive effects are poorly understood. This study assessed whether long-term nitrogen deposition altered sensitivity to ozone in a semi-natural vegetation community. Mesocosms were collected from sand dune grassland in the UK along a nitrogen gradient (5-25 kg N/ha/y, including two plots from a long-term experiment), and fumigated for 2.5 months to simulate medium and high ozone exposure. Ozone damage to leaves was quantified for 20 ozone-sensitive species. Soil solution dissolved organic carbon (DOC) and soil extracellular enzymes were measured to investigate secondary effects on soil processes. Mesocosms from sites receiving the highest N deposition showed the least ozone-related leaf damage, while those from the least N-polluted sites were the most damaged by ozone. This was due to differences in community-level sensitivity, rather than species-level impacts. The N-polluted sites contained fewer ozone-sensitive forbs and sedges, and a higher proportion of comparatively ozone-resistant grasses. This difference in the vegetation composition of mesocosms in relation to N deposition conveyed differential resilience to ozone. Mesocosms in the highest ozone treatment showed elevated soil solution DOC with increasing site N deposition. This suggests that, despite showing relatively little leaf damage, the 'ozone resilient' vegetation community may still sustain physiological damage through reduced capacity to assimilate photosynthate, with its subsequent loss as DOC through the roots into the soil. We conclude that for dune grassland habitats, the regions of highest risk to ozone exposure are those that have received the lowest level of long-term nitrogen deposition. This highlights the importance of considering community- and ecosystem-scale impacts of pollutants in addition to impacts on individual species. It also underscores the need for protection of 'clean' habitats from air pollution and other environmental stressors.
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Affiliation(s)
- Felicity Hayes
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK.
| | - Bethan Lloyd
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK; Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Gina Mills
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK
| | - Laurence Jones
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW, UK
| | - Anthony J Dore
- Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Edward Carnell
- Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Massimo Vieno
- Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Nancy Dise
- Centre for Ecology & Hydrology, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Nathalie Fenner
- Bangor University, School of Natural Sciences, Bangor University, Bangor, Gwynedd, LL57 2DG, UK
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Feng Z, Shang B, Li Z, Calatayud V, Agathokleous E. Ozone will remain a threat for plants independently of nitrogen load. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13422] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Zhaozhong Feng
- Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Institute of Ecology Nanjing University of Information Science & Technology Nanjing China
| | - Bo Shang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco‐Environmental Sciences Chinese Academy of Sciences Beijing China
| | - Zhengzhen Li
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco‐Environmental Sciences Chinese Academy of Sciences Beijing China
| | | | - Evgenios Agathokleous
- Key Laboratory of Agrometeorology of Jiangsu Province, School of Applied Meteorology, Institute of Ecology Nanjing University of Information Science & Technology Nanjing China
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19
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Li P, Zhou H, Xu Y, Shang B, Feng Z. The effects of elevated ozone on the accumulation and allocation of poplar biomass depend strongly on water and nitrogen availability. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 665:929-936. [PMID: 30893752 DOI: 10.1016/j.scitotenv.2019.02.182] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 02/09/2019] [Accepted: 02/12/2019] [Indexed: 06/09/2023]
Abstract
Ozone (O3) pollution can alter carbon allocation and reduce tree growth - both above and below ground, but the extent of these effects depends on the variation in soil water and nutrient availability. Here we present the accumulation and allocation of biomass in poplar clone 546 (Populus deltoides cv. '55/56' × P. deltoides cv. 'Imperial') for one growing season at two O3 concentrations (charcoal-filtered air [CF] and non-filtered air + 40 ppb of O3 [E-O3]), two watering regimes (well-watered [WW] and reduced watering at 40% of WW irrigation [RW]) and two soil nitrogen addition treatments (no addition [N0] and the addition of 50 kg N ha-1 year-1 [N50]). We found that the deleterious effects of E-O3 depended on the supply of water and nitrogen. Specifically, when the supplies of water and/or N (WW and/or N50) were abundant, E-O3 significantly reduced whole plant biomass by >15% but had no significant effect on biomass when these supplies were limited (RW and N0). A significant reduction of biomass by E-O3 occurred earlier in fine roots than in other plant organs, indicating greater sensitivity of fine root to E-O3. These results suggest that rising O3 concentrations may not ubiquitously lead to a large reduction in plant biomass since plant growth is often jointly constrained by water and nutrients.
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Affiliation(s)
- Pin Li
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Huimin Zhou
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China; Institute of Loess Plateau, Shanxi University, Taiyuan 030006, China
| | - Yansen Xu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bo Shang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaozhong Feng
- Institute of Ecology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China.
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Dai L, Hayes F, Sharps K, Harmens H, Mills G. Nitrogen availability does not affect ozone flux-effect relationships for biomass in birch (Betula pendula) saplings. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 660:1038-1046. [PMID: 30743901 DOI: 10.1016/j.scitotenv.2019.01.092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 01/07/2019] [Accepted: 01/09/2019] [Indexed: 06/09/2023]
Abstract
To investigate whether nitrogen (N) load affects the ozone (O3) stomatal flux-effect relationship for birch biomass, three-year old birch saplings were exposed to seven different O3 profiles (24 h mean of 35-66 ppb) and four different N loads (10, 30, 50 and 70 kg ha-1 yr-1) in precision-controlled hemispherical glasshouses (solardomes) in 2012 and 2013. Stomatal conductance (gs) under optimal growth conditions was stimulated by enhanced N supply but was not significantly affected by enhanced O3 exposure. Birch root, woody (stem + branches) and total biomass (root + woody) were not affected by the Phytotoxic Ozone Dose (POD1SPEC) after two seasons of O3 exposure, and enhanced N supply stimulated biomass production independent of POD1SPEC (i.e. there were no POD1SPEC × N interactions). There was a strong linear relationship between the stem cross-sectional area and tree biomass at the end of the experiment, which was not affected by O3 exposure or N load. Enhanced N supply stimulated the stem cross-sectional area at the end of season 2, but not at the end of season 1, which suggests a time lag before tree biomass responded to enhanced N supply. There was no significant effect of POD1SPEC on stem cross-sectional area after either the first or second growing season of the experiment. Contrasting results reported in the literature on the interactive impacts of O3 and N load on tree physiology and growth are likely due to species-specific responses, different duration of the experiments and/or a limitation of the number of O3 and N levels tested.
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Affiliation(s)
- Lulu Dai
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, United Kingdom; State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Shijingshan District, Beijing 100049, China
| | - Felicity Hayes
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, United Kingdom.
| | - Katrina Sharps
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, United Kingdom
| | - Harry Harmens
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, United Kingdom
| | - Gina Mills
- Centre for Ecology & Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, United Kingdom
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21
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Podda A, Pisuttu C, Hoshika Y, Pellegrini E, Carrari E, Lorenzini G, Nali C, Cotrozzi L, Zhang L, Baraldi R, Neri L, Paoletti E. Can nutrient fertilization mitigate the effects of ozone exposure on an ozone-sensitive poplar clone? THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 657:340-350. [PMID: 30550899 DOI: 10.1016/j.scitotenv.2018.11.459] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 11/28/2018] [Accepted: 11/29/2018] [Indexed: 06/09/2023]
Abstract
We tested the independent and interactive effects of nitrogen (N; 0 and 80 kg ha-1), phosphorus (P; 0, 40 and 80 kg ha-1), and ozone (O3) application/exposure [ambient concentration (AA), 1.5 × AA and 2.0 × AA] for five consecutive months on biochemical traits of the O3-sensitive Oxford poplar clone. Plants exposed to O3 showed visible injury and an alteration of membrane integrity, as confirmed by the malondialdehyde by-product accumulation (+3 and +17% under 1.5 × AA and 2.0 × AA conditions, in comparison to AA). This was probably due to O3-induced oxidative damage, as documented by the production of superoxide anion radical (O2-, +27 and +63%, respectively). Ozone per se, independently from the concentrations, induced multiple signals (e.g., alteration of cellular redox state, increase of abscisic acid/indole-3-acetic acid ratio and reduction of proline content) that might be part of premature leaf senescence processes. By contrast, nutrient fertilization (both N and P) reduced reactive oxygen species accumulation (as confirmed by the decreased O2- and hydrogen peroxide content), resulting in enhanced membrane stability. This was probably due to the simultaneous involvement of antioxidant compounds (e.g., carotenoids, ascorbate and glutathione) and osmoprotectants (e.g., proline) that regulate the detoxification processes of coping with oxidative stress by reducing the O3 sensitivity of Oxford clone. These mitigation effects were effective only under AA and 1.5 × AA conditions. Nitrogen and P supply activated a free radical scavenging system that was not able to delay leaf senescence and mitigate the adverse effects of a general peroxidation due to the highest O3 concentrations.
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Affiliation(s)
- Alessandra Podda
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy; Institute for Sustainable Plant Protection, National Research Council, Via Madonna del Piano 10, Sesto Fiorentino, Florence 50019, Italy
| | - Claudia Pisuttu
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy
| | - Yasutomo Hoshika
- Institute for Sustainable Plant Protection, National Research Council, Via Madonna del Piano 10, Sesto Fiorentino, Florence 50019, Italy
| | - Elisa Pellegrini
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy; CIRSEC, Center for Climatic Change Impact, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy.
| | - Elisa Carrari
- Institute for Sustainable Plant Protection, National Research Council, Via Madonna del Piano 10, Sesto Fiorentino, Florence 50019, Italy
| | - Giacomo Lorenzini
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy; CIRSEC, Center for Climatic Change Impact, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy
| | - Cristina Nali
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy; CIRSEC, Center for Climatic Change Impact, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy
| | - Lorenzo Cotrozzi
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, Pisa 56124, Italy
| | - Lu Zhang
- Institute for Sustainable Plant Protection, National Research Council, Via Madonna del Piano 10, Sesto Fiorentino, Florence 50019, Italy; College of Horticulture and Landscape Architecture, Northeast Agricultural University, Changjiang Road 600, Harbin 150030, China
| | - Rita Baraldi
- Institute of Biometeorology, National Research Council, Via P. Gobetti 101, Bologna 40129, Italy
| | - Luisa Neri
- Institute of Biometeorology, National Research Council, Via P. Gobetti 101, Bologna 40129, Italy
| | - Elena Paoletti
- Institute for Sustainable Plant Protection, National Research Council, Via Madonna del Piano 10, Sesto Fiorentino, Florence 50019, Italy
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22
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Wilson SR, Madronich S, Longstreth JD, Solomon KR. Interactive effects of changing stratospheric ozone and climate on tropospheric composition and air quality, and the consequences for human and ecosystem health. Photochem Photobiol Sci 2019; 18:775-803. [PMID: 30810564 DOI: 10.1039/c8pp90064g] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The composition of the air we breathe is determined by emissions, weather, and photochemical transformations induced by solar UV radiation. Photochemical reactions of many emitted chemical compounds can generate important (secondary) pollutants including ground-level ozone (O3) and some particulate matter, known to be detrimental to human health and ecosystems. Poor air quality is the major environmental cause of premature deaths globally, and even a small decrease in air quality can translate into a large increase in the number of deaths. In many regions of the globe, changes in emissions of pollutants have caused significant changes in air quality. Short-term variability in the weather as well as long-term climatic trends can affect ground-level pollution through several mechanisms. These include large-scale changes in the transport of O3 from the stratosphere to the troposphere, winds, clouds, and patterns of precipitation. Long-term trends in UV radiation, particularly related to the depletion and recovery of stratospheric ozone, are also expected to result in changes in air quality as well as the self-cleaning capacity of the global atmosphere. The increased use of substitutes for ozone-depleting substances, in response to the Montreal Protocol, does not currently pose a significant risk to the environment. This includes both the direct emissions of substitutes during use and their atmospheric degradation products (e.g. trifluoroacetic acid, TFA).
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Affiliation(s)
- S R Wilson
- Centre for Atmospheric Chemistry, School of Earth, Atmosphere and Life Sciences, University of Wollongong, NSW, Australia.
| | - S Madronich
- National Center for Atmospheric Research, Boulder, CO, USA
| | - J D Longstreth
- The Institute for Global Risk Research, LLC, Bethesda, MD, USA and Emergent BioSolutions, Gaithersburg, MD, USA
| | - K R Solomon
- Centre for Toxicology and School of Environmental Sciences, University of Guelph, ON, Canada
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23
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Meng C, Liu X, Chai Y, Xu J, Yue M. Another choice for measuring tree photosynthesis in vitro. PeerJ 2019; 7:e5933. [PMID: 30643687 PMCID: PMC6329340 DOI: 10.7717/peerj.5933] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 10/15/2018] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND In the case of tall trees in the field or in rugged terrain where an instrument cannot be placed operationally, beveling is a popular method used to measure in vitro photosynthesis. However, some studies and our own research have shown that net photosynthesis values measured in vitro are generally significantly lower than values measured in situ. METHODS To develop a more accurate and applicable method for in vitro determination of photosynthesis, we evaluated five different methods for preparing detached tree branches to measure photosynthesis and gas exchange in vitro (beveling, cracking, splitting, girdling, and immersion in salicylic acid solution). Ten common tree-species were used. RESULTS By comparing light response curves and water-status data, we found that (1) it is possible, to some extent, to substitute in vitro measurement of photosynthetic characteristics of tree species for in situ measurement, provided a suitable treatment is employed; (2) the beveling method is likely to underestimate photosynthetic potential of some trees; (3) after cracking application, most detached branches effectively continued to absorb water; and (4) measurements obtained using detached tree-branches processed by the cracking method were closer to those obtained in situ in intact trees; (5) some tree species (Diospyros kaki, Eriobotrya japonica) appeared to be particularly sensitive to the cracking method, and their in-vitro maximum net photosynthesis rate (P max) was significantly less than the in-situ value (P < 0.05). DISCUSSION Our findings provide a methodological support for comprehensive and accurate measurement of plant functional traits. The use of the cracking method contributes to feasibility and reliability of the measurement of photosynthetic parameters in tall trees, thus providing more accurate photosynthetic parameters for the analysis of trade-off strategies at the leaf level.
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Affiliation(s)
- Changjun Meng
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi’an, Shaanxi, China
- College of Biology and Environmental Engineering, Xi’an University, Xi’an, Shaanxi, China
| | - Xiao Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi’an, Shaanxi, China
- School of Life Sciences, Northwest University, Xi’an, Shaanxi, China
| | - Yongfu Chai
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi’an, Shaanxi, China
- School of Life Sciences, Northwest University, Xi’an, Shaanxi, China
| | - Jinshi Xu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi’an, Shaanxi, China
| | - Ming Yue
- Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Xi’an, Shaanxi, China
- School of Life Sciences, Northwest University, Xi’an, Shaanxi, China
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24
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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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25
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Xu W, Shang B, Xu Y, Yuan X, Dore AJ, Zhao Y, Massad RS, Feng Z. Effects of elevated ozone concentration and nitrogen addition on ammonia stomatal compensation point in a poplar clone. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 238:760-770. [PMID: 29625300 DOI: 10.1016/j.envpol.2018.03.089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 03/23/2018] [Accepted: 03/25/2018] [Indexed: 05/23/2023]
Abstract
The stomatal compensation point of ammonia (χs) is a key factor controlling plant-atmosphere NH3 exchange, which is dependent on the nitrogen (N) supply and varies among plant species. However, knowledge gaps remain concerning the effects of elevated atmospheric N deposition and ozone (O3) on χs for forest species, resulting in large uncertainties in the parameterizations of NH3 incorporated into atmospheric chemistry and transport models (CTMs). Here, we present leaf-scale measurements of χs for hybrid poplar clone '546' (Populusdeltoides cv. 55/56 x P. deltoides cv. Imperial) growing in two N treatments (N0, no N added; N50, 50 kg N ha-1 yr-1 urea fertilizer added) and two O3 treatments (CF, charcoal-filtered air; E-O3, non-filtered air plus 40 ppb) for 105 days. Our results showed that χs was significantly reduced by E-O3 (41%) and elevated N (19%). The interaction of N and O3 was significant, and N can mitigate the negative effects of O3 on χs. Elevated O3 significantly reduced the light-saturated photosynthetic rate (Asat) and chlorophyll (Chl) content and significantly increased intercellular CO2 concentrations (Ci), but had no significant effect on stomatal conductance (gs). By contrast, elevated N did not significantly affect all measured photosynthetic parameters. Overall, χs was significantly and positively correlated with Asat, gs and Chl, whereas a significant and negative relationship was observed between χs and Ci. Our results suggest that O3-induced changes in Asat, Ci and Chl may affect χs. Our findings provide a scientific basis for optimizing parameterizations of χs in CTMs in response to environmental change factors (i.e., elevated N deposition and/or O3) in the future.
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Affiliation(s)
- Wen Xu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bo Shang
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yansen Xu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xiangyang Yuan
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Anthony J Dore
- Centre for Ecology and Hydrology, Edinburgh, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
| | - Yuanhong Zhao
- Laboratory for Climate and Ocean-Atmosphere Sciences, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, 100871, China
| | - Raia-Silvia Massad
- UMR ECOSYS, INRA, Agroparistech, Université Paris-Saclay, Thiverval-Grignon, France
| | - Zhaozhong Feng
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Shuangqing Road 18, Haidian District, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
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26
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Li C, Song Y, Guo L, Gu X, Muminov MA, Wang T. Nitric oxide alleviates wheat yield reduction by protecting photosynthetic system from oxidation of ozone pollution. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 236:296-303. [PMID: 29414351 DOI: 10.1016/j.envpol.2018.01.093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/25/2018] [Accepted: 01/28/2018] [Indexed: 06/08/2023]
Abstract
Accelerated industrialization has been increasing releases of chemical precursors of ozone. Ozone concentration has risen nowadays, and it's predicted that this trend will continue in the next few decades. The yield of many ozone-sensitive crops suffers seriously from ozone pollution, and there are abundant reports exploring the damage mechanisms of ozone to these crops, such as winter wheat. However, little is known on how to alleviate these negative impacts to increase grain production under elevated ozone. Nitric oxide, as a bioactive gaseous, mediates a variety of physiological processes and plays a central role in response to biotic and abiotic stresses. In the present study, the accumulation of endogenous nitric oxide in wheat leaves was found to increase in response to ozone. To study the functions of nitric oxide, its precursor sodium nitroprusside was spayed to wheat leaves under ozone pollution. Wheat leaves spayed with sodium nitroprusside accumulated less hydrogen peroxide, malondialdehyde and electrolyte leakage under ozone pollution, which can be accounted for by the higher activities of superoxide dismutase and peroxidase than in leaves treated without sodium nitroprusside. Consequently, net photosynthetic rate of wheat treated using sodium nitroprusside was much higher, and yield reduction was alleviated under ozone fumigation. These findings are important for our understanding of the potential roles of nitric oxide in responses of crops in general and wheat in particular to ozone pollution, and provide a viable method to mitigate the detrimental effects on crop production induced by ozone pollution, which is valuable for keeping food security worldwide.
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Affiliation(s)
- Caihong Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, PR China
| | - Yanjie Song
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Liyue Guo
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, PR China
| | - Xian Gu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Mahmud A Muminov
- Laboratory of Environmental Problems, Samarkand State University, Samarkand, Uzbekistan
| | - Tianzuo Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, PR China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, PR China.
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27
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Yu H, Shang H, Cao J, Chen Z. How important is woody tissue photosynthesis in EuCahetus dunnii Maiden and Osmanthus fragrans (Thunb.) Lour. under O 3 stress? ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:2112-2120. [PMID: 29110232 DOI: 10.1007/s11356-017-0584-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Accepted: 10/24/2017] [Indexed: 06/07/2023]
Abstract
Numerous studies have demonstrated the negative effects of elevated O3 on leaf photosynthesis. Within trees, a portion of respired CO2 is assimilated by woody tissue photosynthesis, but its response to elevated O3 remains unclear. Saplings of two evergreen tree species, EuCahetus dunnii Maiden (E. dunnii) and Osmanthus fragrans (Thunb.) Lour. (O. fragrans), were exposed to non-filtered air (NF), 100 nmol mol-1 O3 air (E1) and 150 nmol mol-1 O3 air (E2) in open-top chambers from May 5 to September 5, 2016 (8 h a day; 7 days a week) in subtropical China. In this study, O3 fumigation significantly reduced leaf net photosynthesis rate in both two tree species on most measurements. However, compared with leaf net photosynthesis rate, woody tissue gross photosynthesis rate showed less negative response to O3 fumigation and was even stimulated to increase. Refixation rate reflects the utilization efficiency of the respired CO2 by woody tissue photosynthesis. During the experiment period, E1 and E2 both increased refixation rate in O. fragrans compared with NF. Whereas for E. dunnii, E1 increased refixation rate until 81 days after starting of fumigation and then decreased it, and E2 decreased it all the time. Refixation rate had a significant positive correlation with woody tissue chlorophyll contents, indicating that the response of refixation rate to elevated O3 may relate to chlorophyll contents. All these suggested that under O3 fumigation, when atmospheric CO2 uptake and fixation by leaf is limited, woody tissue photosynthesis can contribute more to the total carbon assimilation in trees. The findings help to understand the significance of woody tissue photosynthesis under elevated O3 conditions.
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Affiliation(s)
- Hao Yu
- Key Laboratory of Forest Ecology and Environment, State Forestry Administration of China, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, 100091, China
| | - He Shang
- Key Laboratory of Forest Ecology and Environment, State Forestry Administration of China, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, 100091, China.
| | - Jixin Cao
- Key Laboratory of Forest Ecology and Environment, State Forestry Administration of China, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, 100091, China
| | - Zhan Chen
- Key Laboratory of Forest Ecology and Environment, State Forestry Administration of China, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, 100091, China
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