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Hasler-Sheetal H. Detrimental impact of sulfide on the seagrass Zostera marina in dark hypoxia. PLoS One 2023; 18:e0295450. [PMID: 38060512 PMCID: PMC10703230 DOI: 10.1371/journal.pone.0295450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023] Open
Abstract
Sulfide poisoning, hypoxia events, and reduced light availability pose threats to marine ecosystems such as seagrass meadows. These threats are projected to intensify globally, largely due to accelerating eutrophication of estuaries and coastal environments. Despite the urgency, our current comprehension of the metabolic pathways that underlie the deleterious effects of sulfide toxicity and hypoxia on seagrasses remains inadequate. To address this knowledge gap, I conducted metabolomic analyses to investigate the impact of sulfide poisoning under dark-hypoxia in vitro conditions on Zostera marina, a vital habitat-forming marine plant. During the initial 45 minutes of dark-hypoxia exposure, I detected an acclimation phase characterized by the activation of anaerobic metabolic pathways and specific biochemical routes that mitigated hypoxia and sulfide toxicity. These pathways served to offset energy imbalances, cytosolic acidosis, and sulfide toxicity. Notably, one such route facilitated the transformation of toxic sulfide into non-toxic organic sulfur compounds, including cysteine and glutathione. However, this sulfide tolerance mechanism exhibited exhaustion post the initial 45-minute acclimation phase. Consequently, after 60 minutes of continuous sulfide exposure, the sulfide toxicity began to inhibit the hypoxia-mitigating pathways, culminating in leaf senescence and tissue degradation. Utilizing metabolomic approaches, I elucidated the intricate metabolic responses of seagrasses to sulfide toxicity under in vitro dark-hypoxic conditions. My findings suggest that future increases in coastal eutrophication will compromise the resilience of seagrass ecosystems to hypoxia, primarily due to the exacerbating influence of sulfide.
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Affiliation(s)
- Harald Hasler-Sheetal
- Nordcee, University of Southern Denmark, Odense M, Denmark
- VILLUM Center for Bioanalytical Sciences, University of Southern Denmark, Odense M, Denmark
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Lamb AL, Chenery CA, Madgwick R, Evans JA. Wet feet: developing sulfur isotope provenance methods to identify wetland inhabitants. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230391. [PMID: 37830031 PMCID: PMC10565411 DOI: 10.1098/rsos.230391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 09/14/2023] [Indexed: 10/14/2023]
Abstract
The stable isotopes of sulfur provide a distinctive signature for marine proximity and interaction. Exploring coastal proximity has been the principal application of sulfur isotopes in archaeology and palaeoecology, but this deals only with high (greater than 14‰) isotope values, meaning little interpretation has been gained from lower values. Progress has been hindered by issues with biosphere mapping. Air pollution can impact modern landscapes, significantly lowering sulfur isotope baselines, leading to the assumption that modern vegetation-based sulfur maps are not reliable. This research explores the potential of previously undiagnostic low, and often, negative sulfur isotope values for identifying wetland dwellers. Impervious clays that support wetlands are distinctive ecosystems and this study tests the hypothesis that they will produce low isotope values owing to both the underlying substrate and to redox conditions. Primary mapping of targeted areas using modern plants highlights zones with natural negative sulfur values and demonstrates that this constitutes a distinctive wetland signature. Analysis of modern and archaeological fauna demonstrates that these distinctive isotope compositions are transferred into the food chain. These findings propel the interpretative potential of sulfur isotopes forward and add to the growing knowledge to provide means for identifying archaeological humans and animals raised in wetlands.
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Affiliation(s)
- Angela L. Lamb
- National Environmental Isotope Facility, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
| | - Carolyn A. Chenery
- National Environmental Isotope Facility, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
| | - Richard Madgwick
- School of History, Archaeology and Religion, Cardiff University, Cardiff CF10 3EU, UK
| | - Jane A. Evans
- National Environmental Isotope Facility, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
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Guiry EJ, Orchard TJ, Needs-Howarth S, Szpak P. Freshwater wetland–driven variation in sulfur isotope compositions: Implications for human paleodiet and ecological research. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.953042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Sulfur isotope (δ34S) analyses are an important archaeological and ecological tool for understanding human and animal migration and diet, but δ34S can be difficult to interpret, particularly in archaeological human-mobility studies, when measured isotope compositions are strongly 34S-depleted relative to regional baselines. Sulfides, which accumulate under anoxic conditions and have distinctively low δ34S, are potentially key for understanding this but are often overlooked in studies of vertebrate δ34S. We analyze an ecologically wide range of archaeological taxa to build an interpretive framework for understanding the impact of sulfide-influenced δ34S on vertebrate consumers. Results provide the first demonstration that δ34S of higher-level consumers can be heavily impacted by freshwater wetland resource use. This source of δ34S variation is significant because it is linked to a globally distributed habitat and occurs at the bottom of the δ34S spectrum, which, for archaeologists, is primarily used for assessing human mobility. Our findings have significant implications for rethinking traditional interpretive frameworks of human mobility and diet, and for exploring the historical ecology of past freshwater wetland ecosystems. Given the tremendous importance of wetlands’ ecosystem services today, such insights on the structure and human dynamics of past wetlands could be valuable for guiding restoration work.
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Spartina alterniflora Invaded Coastal Wetlands by Raising Soil Sulfur Contents: A Meta-Analysis. WATER 2022. [DOI: 10.3390/w14101633] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Nowadays, plant invasion has become a global ecological threat to local biodiversity and ecosystem stability. Spartina alterniflora encroaches on the ecological niches of local species and changes the soil’s nutrient cycle. However, few comprehensive assessments focus on the effects of S. alterniflora invasion. Here, we investigated how soil sulfur changed with spatiotemporal variation and life forms of native species after S. alterniflora invasion and speculated the possible mechanism of the sulfur increase based on the references. The invasion of S. alterniflora increased soil total sulfur by 57.29% and phytotoxic sulfide by 193.29%. In general, the invasion of S. alterniflora enhanced the total plant biomass and soil nutrients, e.g., soil organic carbon, total nitrogen, and soil microbial biomass carbon, further increasing soil sulfur content. The sulfur accumulation caused by S. alterniflora might result in the poisoning of native species. Thus, we hypothesized that the success of S. alterniflora invasion was closely connected with soil sulfur, especially toxic sulfide. Our study suggests that researchers should give more attention to the correlation between S. alterniflora invasion and the soil sulfur increase. More research is needed to investigate the mechanisms of the successful invasion by accumulating phytotoxic sulfide.
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Rolando JL, Kolton M, Song T, Kostka JE. The core root microbiome of Spartina alterniflora is predominated by sulfur-oxidizing and sulfate-reducing bacteria in Georgia salt marshes, USA. MICROBIOME 2022; 10:37. [PMID: 35227326 PMCID: PMC8886783 DOI: 10.1186/s40168-021-01187-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/25/2021] [Indexed: 05/12/2023]
Abstract
BACKGROUND Salt marshes are dominated by the smooth cordgrass Spartina alterniflora on the US Atlantic and Gulf of Mexico coastlines. Although soil microorganisms are well known to mediate important biogeochemical cycles in salt marshes, little is known about the role of root microbiomes in supporting the health and productivity of marsh plant hosts. Leveraging in situ gradients in aboveground plant biomass as a natural laboratory, we investigated the relationships between S. alterniflora primary productivity, sediment redox potential, and the physiological ecology of bulk sediment, rhizosphere, and root microbial communities at two Georgia barrier islands over two growing seasons. RESULTS A marked decrease in prokaryotic alpha diversity with high abundance and increased phylogenetic dispersion was found in the S. alterniflora root microbiome. Significantly higher rates of enzymatic organic matter decomposition, as well as the relative abundances of putative sulfur (S)-oxidizing, sulfate-reducing, and nitrifying prokaryotes correlated with plant productivity. Moreover, these functional guilds were overrepresented in the S. alterniflora rhizosphere and root core microbiomes. Core microbiome bacteria from the Candidatus Thiodiazotropha genus, with the metabolic potential to couple S oxidation with C and N fixation, were shown to be highly abundant in the root and rhizosphere of S. alterniflora. CONCLUSIONS The S. alterniflora root microbiome is dominated by highly active and competitive species taking advantage of available carbon substrates in the oxidized root zone. Two microbially mediated mechanisms are proposed to stimulate S. alterniflora primary productivity: (i) enhanced microbial activity replenishes nutrients and terminal electron acceptors in higher biomass stands, and (ii) coupling of chemolithotrophic S oxidation with carbon (C) and nitrogen (N) fixation by root- and rhizosphere-associated prokaryotes detoxifies sulfide in the root zone while potentially transferring fixed C and N to the host plant. Video Abstract.
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Affiliation(s)
- Jose L Rolando
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
| | - Max Kolton
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
- French Associates Institute for Agriculture and Biotechnology of Drylands, Ben-Gurion, University of the Negev, Beer Sheva, Israel
| | - Tianze Song
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
| | - Joel E Kostka
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA.
- Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA, 30332, USA.
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
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Kolton M, Rolando JL, Kostka JE. Elucidation of the rhizosphere microbiome linked to Spartina alterniflora phenotype in a salt marsh on Skidaway Island, Georgia, USA. FEMS Microbiol Ecol 2020; 96:5813622. [PMID: 32227167 DOI: 10.1093/femsec/fiaa026] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 03/23/2020] [Indexed: 01/04/2023] Open
Abstract
Smooth cordgrass, Spartina alterniflora, dominates salt marshes on the east coast of the United States. While the physicochemical cues affecting S. alterniflora productivity have been studied intensively, the role of plant-microbe interactions in ecosystem functioning remains poorly understood. Thus, in this study, the effects of S. alterniflora phenotype on the composition of archaeal, bacterial, diazotrophic and fungal communities were investigated. Overall, prokaryotic communities were more diverse and bacteria were more abundant in the areas colonized by the tall plant phenotype in comparison to those of short plant phenotype. Diazotrophic methanogens (Methanomicrobia) preferentially colonized the area of the short plant phenotype. Putative iron-oxidizing Zetaproteobacteria and sulfur-oxidizing Campylobacteria were identified as indicator species in the rhizosphere of tall and short plant phenotypes, respectively. Finally, while diazotrophic populations shaped microbial interactions in the areas colonized by the tall plant phenotype, fungal populations filled this role in the areas occupied by the short plant phenotype. The results here demonstrate that S. alterniflora phenotype and proximity to the root zone are selective forces dictating microbial community assembly. Results further reveal that reduction-oxidation chemistry is a major factor driving the selection of belowground microbial populations in salt marsh habitats.
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Affiliation(s)
- Max Kolton
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - José L Rolando
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Joel E Kostka
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.,School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
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Reijers VC, Akker M, Cruijsen PMJM, Lamers LPM, Heide T. Intraspecific facilitation explains the persistence of
Phragmites australis
in modified coastal wetlands. Ecosphere 2019. [DOI: 10.1002/ecs2.2842] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Valérie C. Reijers
- Department of Aquatic Ecology & Environmental Biology Faculty of Science Institute for Water and Wetland Research Radboud University Nijmegen 6525 AJ The Netherlands
| | - Marloes Akker
- Department of Aquatic Ecology & Environmental Biology Faculty of Science Institute for Water and Wetland Research Radboud University Nijmegen 6525 AJ The Netherlands
| | - Peter M. J. M. Cruijsen
- Department of Aquatic Ecology & Environmental Biology Faculty of Science Institute for Water and Wetland Research Radboud University Nijmegen 6525 AJ The Netherlands
| | - Leon P. M. Lamers
- Department of Aquatic Ecology & Environmental Biology Faculty of Science Institute for Water and Wetland Research Radboud University Nijmegen 6525 AJ The Netherlands
| | - Tjisse Heide
- Department of Aquatic Ecology & Environmental Biology Faculty of Science Institute for Water and Wetland Research Radboud University Nijmegen 6525 AJ The Netherlands
- Conservation Ecology Group Groningen Institute for Evolutionary Life Sciences University of Groningen Groningen 9700 CC The Netherlands
- Department Coastal Systems Royal Netherlands Institute for Sea Research and Utrecht University Den Burg 1790 AB The Netherlands
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8
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Yuan J, Ding W, Liu D, Kang H, Xiang J, Lin Y. Shifts in methanogen community structure and function across a coastal marsh transect: effects of exotic Spartina alterniflora invasion. Sci Rep 2016; 6:18777. [PMID: 26728134 PMCID: PMC4700438 DOI: 10.1038/srep18777] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 11/26/2015] [Indexed: 11/08/2022] Open
Abstract
Invasion of Spartina alterniflora in coastal areas of China increased methane (CH4) emissions. To elucidate the underlying mechanisms, we measured CH4 production potential, methanogen community structure and biogeochemical factors along a coastal wetland transect comprised of five habitat regions: open water, bare tidal flat, invasive S. alterniflora marsh and native Suaeda salsa and Phragmites australis marshes. CH4 production potential in S. alterniflora marsh was 10 times higher than that in other regions, and it was significantly correlated with soil organic carbon, dissolved organic carbon and trimethylamine concentrations, but was not correlated with acetate or formate concentrations. Although the diversity of methanogens was lowest in S. alterniflora marsh, invasion increased methanogen abundance by 3.48-fold, compared with native S. salsa and P. australis marshes due to increase of facultative Methanosarcinaceae rather than acetotrophic and hydrogenotrophic methanogens. Ordination analyses suggested that trimethylamine was the primary factor regulating shift in methanogen community structure. Addition of trimethylamine increased CH4 production rates by 1255-fold but only by 5.61- and 11.4-fold for acetate and H2/CO2, respectively. S. alterniflora invasion elevated concentration of non-competitive trimethylamine, and shifted methanogen community from acetotrophic to facultative methanogens, which together facilitated increased CH4 production potential.
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Affiliation(s)
- Junji Yuan
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 10049, China
| | - Weixin Ding
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Deyan Liu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Hojeong Kang
- School of Civil and Environmental Engineering, Yonsei University, Seoul 120–749, Korea
| | - Jian Xiang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 10049, China
| | - Yongxin Lin
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
- University of Chinese Academy of Sciences, Beijing 10049, China
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9
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Lamers LPM, Govers LL, Janssen ICJM, Geurts JJM, Van der Welle MEW, Van Katwijk MM, Van der Heide T, Roelofs JGM, Smolders AJP. Sulfide as a soil phytotoxin-a review. FRONTIERS IN PLANT SCIENCE 2013; 4:268. [PMID: 23885259 PMCID: PMC3717504 DOI: 10.3389/fpls.2013.00268] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Accepted: 07/02/2013] [Indexed: 05/17/2023]
Abstract
In wetland soils and underwater sediments of marine, brackish and freshwater systems, the strong phytotoxin sulfide may accumulate as a result of microbial reduction of sulfate during anaerobiosis, its level depending on prevailing edaphic conditions. In this review, we compare an extensive body of literature on phytotoxic effects of this reduced sulfur compound in different ecosystem types, and review the effects of sulfide at multiple ecosystem levels: the ecophysiological functioning of individual plants, plant-microbe associations, and community effects including competition and facilitation interactions. Recent publications on multi-species interactions in the rhizosphere show even more complex mechanisms explaining sulfide resistance. It is concluded that sulfide is a potent phytotoxin, profoundly affecting plant fitness and ecosystem functioning in the full range of wetland types including coastal systems, and at several levels. Traditional toxicity testing including hydroponic approaches generally neglect rhizospheric effects, which makes it difficult to extrapolate results to real ecosystem processes. To explain the differential effects of sulfide at the different organizational levels, profound knowledge about the biogeochemical, plant physiological and ecological rhizosphere processes is vital. This information is even more important, as anthropogenic inputs of sulfur into freshwater ecosystems and organic loads into freshwater and marine systems are still much higher than natural levels, and are steeply increasing in Asia. In addition, higher temperatures as a result of global climate change may lead to higher sulfide production rates in shallow waters.
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Affiliation(s)
- Leon P. M. Lamers
- Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland Research, Radboud University NijmegenNijmegen, Netherlands
| | - Laura L. Govers
- Department of Environmental Science, Institute for Water and Wetland Research, Radboud University NijmegenNijmegen, Netherlands
| | | | | | | | - Marieke M. Van Katwijk
- Department of Environmental Science, Institute for Water and Wetland Research, Radboud University NijmegenNijmegen, Netherlands
| | - Tjisse Van der Heide
- Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland Research, Radboud University NijmegenNijmegen, Netherlands
- Community and Conservation Ecology Group, Centre for Ecological and Evolutionary Studies, University of GroningenGroningen, Netherlands
| | - Jan G. M. Roelofs
- Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland Research, Radboud University NijmegenNijmegen, Netherlands
| | - Alfons J. P. Smolders
- Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland Research, Radboud University NijmegenNijmegen, Netherlands
- B-WARE Research Centre, Radboud University NijmegenNijmegen, Netherlands
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10
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Lamers LPM, Govers LL, Janssen ICJM, Geurts JJM, Van der Welle MEW, Van Katwijk MM, Van der Heide T, Roelofs JGM, Smolders AJP. Sulfide as a soil phytotoxin-a review. FRONTIERS IN PLANT SCIENCE 2013. [PMID: 23885259 DOI: 10.3389/fpls2013.00268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
In wetland soils and underwater sediments of marine, brackish and freshwater systems, the strong phytotoxin sulfide may accumulate as a result of microbial reduction of sulfate during anaerobiosis, its level depending on prevailing edaphic conditions. In this review, we compare an extensive body of literature on phytotoxic effects of this reduced sulfur compound in different ecosystem types, and review the effects of sulfide at multiple ecosystem levels: the ecophysiological functioning of individual plants, plant-microbe associations, and community effects including competition and facilitation interactions. Recent publications on multi-species interactions in the rhizosphere show even more complex mechanisms explaining sulfide resistance. It is concluded that sulfide is a potent phytotoxin, profoundly affecting plant fitness and ecosystem functioning in the full range of wetland types including coastal systems, and at several levels. Traditional toxicity testing including hydroponic approaches generally neglect rhizospheric effects, which makes it difficult to extrapolate results to real ecosystem processes. To explain the differential effects of sulfide at the different organizational levels, profound knowledge about the biogeochemical, plant physiological and ecological rhizosphere processes is vital. This information is even more important, as anthropogenic inputs of sulfur into freshwater ecosystems and organic loads into freshwater and marine systems are still much higher than natural levels, and are steeply increasing in Asia. In addition, higher temperatures as a result of global climate change may lead to higher sulfide production rates in shallow waters.
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Affiliation(s)
- Leon P M Lamers
- Department of Aquatic Ecology and Environmental Biology, Institute for Water and Wetland Research, Radboud University Nijmegen Nijmegen, Netherlands
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11
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Pezeshki SR, DeLaune RD. Soil oxidation-reduction in wetlands and its impact on plant functioning. BIOLOGY 2012; 1:196-221. [PMID: 24832223 PMCID: PMC4009779 DOI: 10.3390/biology1020196] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Revised: 06/28/2012] [Accepted: 06/29/2012] [Indexed: 11/16/2022]
Abstract
Soil flooding in wetlands is accompanied by changes in soil physical and chemical characteristics. These changes include the lowering of soil redox potential (Eh) leading to increasing demand for oxygen within the soil profile as well as production of soil phytotoxins that are by-products of soil reduction and thus, imposing potentially severe stress on plant roots. Various methods are utilized for quantifying plant responses to reducing soil conditions that include measurement of radial oxygen transport, plant enzymatic responses, and assessment of anatomical/morphological changes. However, the chemical properties and reducing nature of soil environment in which plant roots are grown, including oxygen demand, and other associated processes that occur in wetland soils, pose a challenge to evaluation and comparison of plant responses that are reported in the literature. This review emphasizes soil-plant interactions in wetlands, drawing attention to the importance of quantifying the intensity and capacity of soil reduction for proper evaluation of wetland plant responses, particularly at the process and whole-plant levels. Furthermore, while root oxygen-deficiency may partially account for plant stress responses, the importance of soil phytotoxins, produced as by-products of low soil Eh conditions, is discussed and the need for development of methods to allow differentiation of plant responses to reduced or anaerobic soil conditions vs. soil phytotoxins is emphasized.
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Affiliation(s)
- S R Pezeshki
- Department of Biological Sciences, University of Memphis, Memphis, TN 38152, USA.
| | - R D DeLaune
- Department of Oceanography of Coastal Sciences, School of Coast & Environment, Louisiana State University, Baton Rouge, LA 70803, USA.
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12
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13
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Zhao FJ, Tausz M, De Kok LJ. Role of Sulfur for Plant Production in Agricultural and Natural Ecosystems. SULFUR METABOLISM IN PHOTOTROPHIC ORGANISMS 2008. [DOI: 10.1007/978-1-4020-6863-8_21] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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14
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Miller HL, Meile C, Burd AB. A novel 2D model of internal O2 dynamics and H2S intrusion in seagrasses. Ecol Modell 2007. [DOI: 10.1016/j.ecolmodel.2007.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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15
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Elliott EM, Brush GS. Sedimented organic nitrogen isotopes in freshwater wetlands record long-term changes in watershed nitrogen source and land use. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2006; 40:2910-6. [PMID: 16719090 DOI: 10.1021/es051587q] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Although historic land use is widely recognized as an important determinant of watershed N cycling, efforts to examine land use legacy effects are limited by incomplete historical data. This research evaluates N isotopes of sedimented organic matter (delta15N(org)), in a palynological context, as a long-term proxy of changes in N source to wetland biota. N and S isotope measurements of organic sediments, fossil plant fragments, and living plants are used to explore isotope stratigraphies of wetland sediment cores. Processes potentially contributing to isotope stratigraphies are investigated including the following: a change in N source, diagenesis, and denitrification. We document the delta15N(org) stratigraphy of a core from the Smithsonian Environmental Research Center, MD, U.S.A. spans approximately 350 years, during which time delta15N(org) increases from +2 per thousand to +7 per thousand. Reconstructed population density and wastewater inputs to the watershed suggest that the increase in delta15N reflects changing land use from forested conditions to increasing nutrient inputs from human waste. Our results illustrate the importance of hydrologic connectivity in delivering waste-derived N in a watershed characterized by relatively low human population density. These results also demonstrate how this approach can expand the temporal horizon over which we can assess human impacts to watershed N dynamics.
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Affiliation(s)
- Emily M Elliott
- Department of Geography and Environmental Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
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16
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Devereux R. Seagrass rhizosphere microbial communities. COASTAL AND ESTUARINE STUDIES 2005. [DOI: 10.1029/ce060p0199] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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17
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Jędrysek MO. Sulphur and oxygen isotope ratios in spruce needles as a tracer of atmospheric pollution. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2001jd000527] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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18
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Küsel K, Pinkart HC, Drake HL, Devereux R. Acetogenic and sulfate-reducing bacteria inhabiting the rhizoplane and deep cortex cells of the sea grass Halodule wrightii. Appl Environ Microbiol 1999; 65:5117-23. [PMID: 10543830 PMCID: PMC91688 DOI: 10.1128/aem.65.11.5117-5123.1999] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent declines in sea grass distribution underscore the importance of understanding microbial community structure-function relationships in sea grass rhizospheres that might affect the viability of these plants. Phospholipid fatty acid analyses showed that sulfate-reducing bacteria and clostridia were enriched in sediments colonized by the sea grasses Halodule wrightii and Thalassia testudinum compared to an adjacent unvegetated sediment. Most-probable-number analyses found that in contrast to butyrate-producing clostridia, acetogens and acetate-utilizing sulfate reducers were enriched by an order of magnitude in rhizosphere sediments. Although sea grass roots are oxygenated in the daytime, colorimetric root incubation studies demonstrated that acetogenic O-demethylation and sulfidogenic iron precipitation activities were tightly associated with washed, sediment-free H. wrightii roots. This suggests that the associated anaerobes are able to tolerate exposure to oxygen. To localize and quantify the anaerobic microbial colonization, root thin sections were hybridized with newly developed (33)P-labeled probes that targeted (i) low-G+C-content gram-positive bacteria, (ii) cluster I species of clostridia, (iii) species of Acetobacterium, and (iv) species of Desulfovibrio. Microautoradiography revealed intercellular colonization of the roots by Acetobacterium and Desulfovibrio species. Acetogenic bacteria occurred mostly in the rhizoplane and outermost cortex cell layers, and high numbers of sulfate reducers were detected on all epidermal cells and inward, colonizing some 60% of the deepest cortex cells. Approximately 30% of epidermal cells were colonized by bacteria that hybridized with an archaeal probe, strongly suggesting the presence of methanogens. Obligate anaerobes within the roots might contribute to the vitality of sea grasses and other aquatic plants and to the biogeochemistry of the surrounding sediment.
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Affiliation(s)
- K Küsel
- Gulf Ecology Division, U.S. EPA/National Health and Environmental Effects Research Laboratory, Gulf Breeze, Florida 32561, USA
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King GM, Garey MA. Ferric iron reduction by bacteria associated with the roots of freshwater and marine macrophytes. Appl Environ Microbiol 1999; 65:4393-8. [PMID: 10508065 PMCID: PMC91583 DOI: 10.1128/aem.65.10.4393-4398.1999] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In vitro assays of washed, excised roots revealed maximum potential ferric iron reduction rates of >100 micromol g (dry weight)(-1) day(-1) for three freshwater macrophytes and rates between 15 and 83 micromol (dry weight)(-1) day(-1) for two marine species. The rates varied with root morphology but not consistently (fine root activity exceeded smooth root activity in some but not all cases). Sodium molybdate added at final concentrations of 0.2 to 20 mM did not inhibit iron reduction by roots of marine macrophytes (Spartina alterniflora and Zostera marina). Roots of a freshwater macrophyte, Sparganium eurycarpum, that were incubated with an analog of humic acid precursors, anthroquinone disulfate (AQDS), reduced freshly precipitated iron oxyhydroxide contained in dialysis bags that excluded solutes with molecular weights of >1,000; no reduction occurred in the absence of AQDS. Bacterial enrichment cultures and isolates from freshwater and marine roots used a variety of carbon and energy sources (e.g., acetate, ethanol, succinate, toluene, and yeast extract) and ferric oxyhydroxide, ferric citrate, uranate, and AQDS as terminal electron acceptors. The temperature optima for a freshwater isolate and a marine isolate were equivalent (approximately 32 degrees C). However, iron reduction by the freshwater isolate decreased with increasing salinity, while reduction by the marine isolate displayed a relatively broad optimum salinity between 20 and 35 ppt. Our results suggest that by participating in an active iron cycle and perhaps by reducing humic acids, iron reducers in the rhizoplane of aquatic macrophytes limit organic availability to other heterotrophs (including methanogens) in the rhizosphere and bulk sediments.
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Affiliation(s)
- G M King
- Darling Marine Center, University of Maine, Walpole, Maine 04573, USA.
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Peterson BJ. Stable isotopes as tracers of organic matter input and transfer in benthic food webs: A review. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 1999. [DOI: 10.1016/s1146-609x(99)00120-4] [Citation(s) in RCA: 215] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Okada N, Sasaki A. Sulfur isotopic composition of mangroves. ISOTOPES IN ENVIRONMENTAL AND HEALTH STUDIES 1997; 33:61-65. [PMID: 22087482 DOI: 10.1080/10256019708036332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Abstract Sulfur isotope ratios of mangrove leaves of 19 species were compared to discuss the species-specific characteristics of sulfur uptake and assimilation. The members of Rhizophora and Bruguiera always show remarkable enrichments of the light isotope, giving negative δ(34)S values in most cases. The elaborated root systems of such species seem to be closely related to their sulfur absorbing systems as an adaptation to their anaerobic soil conditions.
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Affiliation(s)
- N Okada
- a Forestry and Forest Products Research Institute, Tsukuba Norin Kenkyu Danchi-nai , Ibaraki , Japan
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Howes BL, Teal JM. Oxygen loss from Spartina alterniflora and its relationship to salt marsh oxygen balance. Oecologia 1994; 97:431-438. [PMID: 28313730 DOI: 10.1007/bf00325879] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/1993] [Accepted: 11/30/1993] [Indexed: 11/25/2022]
Abstract
Spartina alterniflora has been reported to lose significant amounts of oxygen to its rhizosphere with potentially important effects on salt-marsh biogeochemical cycling and plant productivity. The potential significance of this oxidative pathway was evaluated using laboratory split-chamber experiments to quantify oxygen loss from intact root systems under a wide variety of pre-treatment and incubation conditions including antibiotics to inhibit microbial respiration. The aerenchyma system of S. alterniflora was found to transport O2, N2, Ar, and CH4 from above-ground sources to its below-ground roots and rhizomes. While non-respiratory gases were observed to move from the lacunae to water bathing the root systems, net O2 loss did not occur; instead oxygen present outside of the roots/rhizomes was consumed. Net oxygen loss was found when resistance to gas transport was reduced in the lacunae-rhizosphere pathway by placing the root systems in a gas phase and when plant respiration was significantly reduced. Root system respiration appeared to be the major variable in the plant oxygen balance. When root and rhizome respiration was inhibited using poisons or lowered by cooling, the oxygen deficit was greatly reduced and oxygen loss was indicated. The effect of seasonal temperature changes on root system "oxygen deficit" presents a possible explanation as to why Spartina produces root systems with respiration rates that cannot be supported by gas transport. Overall, while oxygen loss from individual plant roots is likely, integrating measured root system oxygen loss with geochemical data indicates that the mass amount of oxygen lost from S. alterniflora root systems is small compared to the total oxygen balance of vegetated salt marsh sediments.
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Affiliation(s)
- B L Howes
- Biology Department, Woods Hole Oceanographic Institution, 02543, Woods Hole, MA, USA
| | - J M Teal
- Biology Department, Woods Hole Oceanographic Institution, 02543, Woods Hole, MA, USA
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TRUST BA, FRY B. Stable sulphur isotopes in plants: a review. PLANT, CELL AND ENVIRONMENT 1992; 15:1105-1110. [PMID: 0 DOI: 10.1111/j.1365-3040.1992.tb01661.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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Arenovski AL, Howes BL. Lacunal allocation and gas transport capacity in the salt marsh grass Spartina alterniflora. Oecologia 1992; 90:316-322. [DOI: 10.1007/bf00317687] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/1991] [Accepted: 01/09/1992] [Indexed: 11/30/2022]
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δ13C Measurements as Indicators of Carbon Flow in Marine and Freshwater Ecosystems. STABLE ISOTOPES IN ECOLOGICAL RESEARCH 1989. [DOI: 10.1007/978-1-4612-3498-2_12] [Citation(s) in RCA: 127] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
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The Use of Stable Sulfur Isotope Ratios in Air Pollution Studies: An Ecosystem Approach in South Florida. ACTA ACUST UNITED AC 1989. [DOI: 10.1007/978-1-4612-3498-2_27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Krouse HR. Sulfur Isotope Studies of the Pedosphere and Biosphere. STABLE ISOTOPES IN ECOLOGICAL RESEARCH 1989. [DOI: 10.1007/978-1-4612-3498-2_24] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Peterson BJ, Howarth RW, Garritt RH. Multiple Stable Isotopes Used to Trace the Flow of Organic Matter in Estuarine Food Webs. Science 1985; 227:1361-3. [PMID: 17793771 DOI: 10.1126/science.227.4692.1361] [Citation(s) in RCA: 132] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The use of a combination of the stable isotopes of sulfur, carbon, and nitrogen allows the flow of organic matter and trophic relations in salt marshes and estuaries to be traced while eliminating many ambiguities that accompany the use of a single isotopic tracer. Salt-marsh grasses take up the isotopically light sulfides formed during sulfate reduction, and the transfer of this light sulfur through the marsh food web is illustrated with data on the ribbed mussel (Geukensia demissa) from various locations in a New England marsh. The multiple isotope approach shows that this filter feeder consumes both marsh grass ( Spartina) detritus and plankton, with the relative proportions of each determined by the location of the mussels in the marsh.
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Hitchcock D, Black M. 34S/32S Evidence of biogenic sulfur oxides in a salt marsh atmosphere. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/0004-6981(84)90224-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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King GM, Klug MJ, Wiegert RG, Chalmers AG. Relation of Soil Water Movement and Sulfide Concentration to Spartina alterniflora Production in a Georgia Salt Marsh. Science 1982; 218:61-3. [PMID: 17776710 DOI: 10.1126/science.218.4567.61] [Citation(s) in RCA: 160] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
It is proposed that differences in plant height and productivity of the salt-marsh cordgrass Spartina alterniflora are the result of a dynamic interaction among tidal water movement, dissolved iron and sulfide concentrations in marsh soils, and bacterial sulfate reduction. Tidal water movement regulates the input of iron into marsh soils and the drainage of sulfide-containing interstitial water, and thereby controls the concentration of dissolved sulfide formed as a result of bacterial sulfate reduction. Near tidal creeks, where water movement and plant height and production are greatest, sulfide concentrations are lowest; in more elevated regions of marsh, where water movement andplant production are least, sulfide concentrations are highest. Plant height and productivity may be limited by the effects of sulfide on nutrient uptake.
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