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Li G, Wu J, Kronzucker HJ, Li B, Shi W. Physiological and molecular mechanisms of plant-root responses to iron toxicity. JOURNAL OF PLANT PHYSIOLOGY 2024; 297:154257. [PMID: 38688043 DOI: 10.1016/j.jplph.2024.154257] [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: 03/29/2024] [Revised: 04/17/2024] [Accepted: 04/22/2024] [Indexed: 05/02/2024]
Abstract
The chemical form and physiological activity of iron (Fe) in soil are dependent on soil pH and redox potential (Eh), and Fe levels in soils are frequently elevated to the point of causing Fe toxicity in plants, with inhibition of normal physiological activities and of growth and development. In this review, we describe how iron toxicity triggers important physiological changes, including nitric-oxide (NO)-mediated potassium (K+) efflux at the tips of roots and accumulation of reactive oxygen species (ROS) and reactive nitrogen (RNS) in roots, resulting in physiological stress. We focus on the root system, as the first point of contact with Fe in soil, and describe the key processes engaged in Fe transport, distribution, binding, and other mechanisms that are drawn upon to defend against high-Fe stress. We describe the root-system regulation of key physiological processes and of morphological development through signaling substances such as ethylene, auxin, reactive oxygen species, and nitric oxide, and discuss gene-expression responses under high Fe. We especially focus on studies on the physiological and molecular mechanisms in rice and Arabidopsis under high Fe, hoping to provide a valuable theoretical basis for improving the ability of crop roots to adapt to soil Fe toxicity.
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Affiliation(s)
- Guangjie Li
- State Key Laboratory of Nutrient Use and Management, Institute of Agricultural Resources and Environment, Shandong Academy of Agricultural Sciences, Jinan, 250100, China.
| | - Jinlin Wu
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; University of the Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing, 100049, China
| | - Herbert J Kronzucker
- School of BioSciences, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Baohai Li
- MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Weiming Shi
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China; International Research Centre for Environmental Membrane Biology, Foshan University, Foshan, 528000, China; University of the Chinese Academy of Sciences, No. 19(A) Yuquan Road, Shijingshan District, Beijing, 100049, China.
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2
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A D, Zhang Y, Huang H, Pan Y, Di HJ, Yi Y, Zhang X, Yang J. Unraveling the mechanism of interaction: accelerated phenanthrene degradation and rhizosphere biofilm/iron plaque formation influenced by phenolic root exudates. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:35853-35863. [PMID: 38743334 DOI: 10.1007/s11356-024-33349-z] [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: 12/04/2023] [Accepted: 04/12/2024] [Indexed: 05/16/2024]
Abstract
Phenolic root exudates (PREs) secreted by wetland plants facilitate the accumulation of iron in the rhizosphere, potentially providing the essential active iron required for the generation of enzymes that degrade polycyclic aromatic hydrocarbon, thereby enhancing their biodegradation. However, the underlying mechanisms involved are yet to be elucidated. This study focuses on phenanthrene (PHE), a typical polycyclic aromatic hydrocarbon pollutant, utilizing representative PREs from wetland plants, including p-hydroxybenzoic, p-coumaric, caffeic, and ferulic acids. Using hydroponic experiments, 16S rRNA sequencing, and multiple characterization techniques, we aimed to elucidate the interaction mechanism between the accelerated degradation of PHE and the formation of rhizosphere biofilm/iron plaque influenced by PREs. Although all four types of PREs altered the biofilm composition and promoted the formation of iron plaque on the root surface, only caffeic acid, possessing a similar structure to the intermediate metabolite of PHE (catechol), could accelerate the PHE degradation rate. Caffeic acid, notable for its catechol structure, plays a significant role in enhancing PHE degradation through two main mechanisms: (a) it directly boosts PHE co-metabolism by fostering the growth of PHE-degrading bacteria, specifically Burkholderiaceae, and by facilitating the production of the key metabolic enzyme catechol 1,2-dioxygenase (C12O) and (b) it indirectly supports PHE biodegradation by promoting iron plaque formation on root surfaces, thereby enriching free iron for efficient microbial synthesis of C12O, a crucial factor in PHE decomposition.
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Affiliation(s)
- Dan A
- Guangdong Provincial Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
- Centre for Soil and Environmental Research, Lincoln University, Lincoln, 7647, Christchurch, New Zealand
| | - Yifei Zhang
- Guangdong Provincial Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Hanjie Huang
- Guangdong Provincial Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Yuan Pan
- Guangdong Provincial Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Hong J Di
- Centre for Soil and Environmental Research, Lincoln University, Lincoln, 7647, Christchurch, New Zealand
| | - Yunqiang Yi
- Guangdong Provincial Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Xiaomeng Zhang
- Department of Ecology, Jinan University, Guangzhou, 510632, China.
| | - Jiewen Yang
- Guangdong Provincial Engineering and Technology Research Center for Agricultural Land Pollution Prevention and Control, College of Resources and Environment, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
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3
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Chan CS, Dykes GE, Hoover RL, Limmer MA, Seyfferth AL. Gallionellaceae in rice root plaque: metabolic roles in iron oxidation, nutrient cycling, and plant interactions. Appl Environ Microbiol 2023; 89:e0057023. [PMID: 38009924 PMCID: PMC10734482 DOI: 10.1128/aem.00570-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 09/18/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE In waterlogged soils, iron plaque forms a reactive barrier between the root and soil, collecting phosphate and metals such as arsenic and cadmium. It is well established that iron-reducing bacteria solubilize iron, releasing these associated elements. In contrast, microbial roles in plaque formation have not been clear. Here, we show that there is a substantial population of iron oxidizers in plaque, and furthermore, that these organisms (Sideroxydans and Gallionella) are distinguished by genes for plant colonization and nutrient fixation. Our results suggest that iron-oxidizing and iron-reducing bacteria form and remodel iron plaque, making it a dynamic system that represents both a temporary sink for elements (P, As, Cd, C, etc.) as well as a source. In contrast to abiotic iron oxidation, microbial iron oxidation results in coupled Fe-C-N cycling, as well as microbe-microbe and microbe-plant ecological interactions that need to be considered in soil biogeochemistry, ecosystem dynamics, and crop management.
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Affiliation(s)
- Clara S. Chan
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
- School of Marine Science and Policy, University of Delaware, Newark, Delaware, USA
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Delaware Biotechnology Institute, Newark, Delaware, USA
| | - Gretchen E. Dykes
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Delaware Biotechnology Institute, Newark, Delaware, USA
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, USA
| | - Rene L. Hoover
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
- Microbiology Graduate Program, University of Delaware, Newark, Delaware, USA
- Delaware Biotechnology Institute, Newark, Delaware, USA
| | - Matt A. Limmer
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, USA
| | - Angelia L. Seyfferth
- Department of Earth Sciences, University of Delaware, Newark, Delaware, USA
- Department of Plant and Soil Sciences, University of Delaware, Newark, Delaware, USA
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4
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Shi J, Wang Z, Peng Y, Fan Z, Zhang Z, Wang X, Zhu K, Shang J, Wang J. Effects of Microplastics on Soil Carbon Mineralization: The Crucial Role of Oxygen Dynamics and Electron Transfer. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:13588-13600. [PMID: 37647508 DOI: 10.1021/acs.est.3c02133] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Although our understanding of the effects of microplastics on the dynamics of soil organic matter (SOM) has considerably advanced in recent years, the fundamental mechanisms remain unclear. In this study, we examine the effects of polyethylene and poly(lactic acid) microplastics on SOM processes via mineralization incubation. Accordingly, we evaluated the changes in carbon dioxide (CO2) and methane (CH4) production. An O2 planar optical sensor was used to detect the temporal behavior of dissolved O2 during incubation to determine the microscale oxygen heterogeneity caused by microplastics. Additionally, the changes in soil dissolved organic matter (DOM) were evaluated using a combination of spectroscopic approaches and ultrahigh-resolution mass spectrometry. Microplastics increased cumulative CO2 emissions by 160-613%, whereas CH4 emissions dropped by 45-503%, which may be attributed to the oxygenated porous habitats surrounding microplastics. Conventional and biodegradable microplastics changed the quantities of soil dissolved organic carbon. In the microplastic treatments, DOM with more polar groups was detected, suggesting a higher level of electron transport. In addition, there was a positive correlation between the carbon concentration, electron-donating ability, and CO2 emission. These findings suggest that microplastics may facilitate the mineralization of SOM by modifying O2 microenvironments, DOM concentration, and DOM electron transport capability. Accordingly, this study provides new insights into the impact of microplastics on soil carbon dynamics.
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Affiliation(s)
- Jia Shi
- Key Laboratory of Arable Land Conservation (North China), College of Land Science and Technology, China Agricultural University, Beijing 100193, People's Republic of China
| | - Zi Wang
- Key Laboratory of Arable Land Conservation (North China), College of Land Science and Technology, China Agricultural University, Beijing 100193, People's Republic of China
| | - Yumei Peng
- Key Laboratory of Arable Land Conservation (North China), College of Land Science and Technology, China Agricultural University, Beijing 100193, People's Republic of China
| | - Zhongmin Fan
- Key Laboratory of Arable Land Conservation (North China), College of Land Science and Technology, China Agricultural University, Beijing 100193, People's Republic of China
| | - Ziyun Zhang
- Key Laboratory of Arable Land Conservation (North China), College of Land Science and Technology, China Agricultural University, Beijing 100193, People's Republic of China
| | - Xiang Wang
- Key Laboratory of Arable Land Conservation (North China), College of Land Science and Technology, China Agricultural University, Beijing 100193, People's Republic of China
| | - Kun Zhu
- Key Laboratory of Arable Land Conservation (North China), College of Land Science and Technology, China Agricultural University, Beijing 100193, People's Republic of China
| | - Jianying Shang
- Key Laboratory of Arable Land Conservation (North China), College of Land Science and Technology, China Agricultural University, Beijing 100193, People's Republic of China
| | - Jie Wang
- Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, People's Republic of China
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5
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Bhattacharyya A, Mavrodi O, Bhowmik N, Weller D, Thomashow L, Mavrodi D. Bacterial biofilms as an essential component of rhizosphere plant-microbe interactions. METHODS IN MICROBIOLOGY 2023; 53:3-48. [PMID: 38415193 PMCID: PMC10898258 DOI: 10.1016/bs.mim.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Affiliation(s)
- Ankita Bhattacharyya
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Olga Mavrodi
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Niladri Bhowmik
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - David Weller
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA, United States
| | - Linda Thomashow
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA, United States
| | - Dmitri Mavrodi
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
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6
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Jiménez JDLC, Pedersen O. Mitigation of Greenhouse Gas Emissions from Rice via Manipulation of Key Root Traits. RICE (NEW YORK, N.Y.) 2023; 16:24. [PMID: 37160782 PMCID: PMC10169991 DOI: 10.1186/s12284-023-00638-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 04/18/2023] [Indexed: 05/11/2023]
Abstract
Rice production worldwide represents a major anthropogenic source of greenhouse gas emissions. Nitrogen fertilization and irrigation practices have been fundamental to achieve optimal rice yields, but these agricultural practices together with by-products from plants and microorganisms, facilitate the production, accumulation and venting of vast amounts of CO2, CH4 and N2O. We propose that the development of elite rice varieties should target root traits enabling an effective internal O2 diffusion, via enlarged aerenchyma channels. Moreover, gas tight barriers impeding radial O2 loss in basal parts of the roots will increase O2 diffusion to the root apex where molecular O2 diffuses into the rhizosphere. These developments result in plants with roots penetrating deeper into the flooded anoxic soils, producing higher volumes of oxic conditions in the interface between roots and rhizosphere. Molecular O2 in these zones promotes CH4 oxidation into CO2 by methanotrophs and nitrification (conversion of NH4+ into NO3-), reducing greenhouse gas production and at the same time improving plant nutrition. Moreover, roots with tight barriers to radial O2 loss will have restricted diffusional entry of CH4 produced in the anoxic parts of the rhizosphere and therefore plant-mediated diffusion will be reduced. In this review, we describe how the exploitation of these key root traits in rice can potentially reduce greenhouse gas emissions from paddy fields.
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Affiliation(s)
- Juan de la Cruz Jiménez
- Department of Biology, University of Copenhagen, Universitetsparken 4, 3rd floor, Copenhagen, 2100, Denmark.
| | - Ole Pedersen
- Department of Biology, University of Copenhagen, Universitetsparken 4, 3rd floor, Copenhagen, 2100, Denmark.
- School of Agriculture and Environment, The University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
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7
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He Y, Ding N, Yu G, Sunahara GI, Lin H, Zhang X, Ullah H, Liu J. High-resolution imaging of O 2 dynamics and metal solubilization in the rhizosphere of the hyperaccumulator Leersia hexandra Swartz. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131580. [PMID: 37167872 DOI: 10.1016/j.jhazmat.2023.131580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 04/25/2023] [Accepted: 05/03/2023] [Indexed: 05/13/2023]
Abstract
The mobilization of trace metals in the rhizosphere can be affected by the redox potential, which is closely related to the O2 dynamics. This study examined the distributions of O2 and trace metals in the rhizosphere of the subaquatic hyperaccumulator Leersia hexandra Swartz under chromium (Cr) stress using planar optodes and the diffusive gradients in thin films technique coupled with laser ablation inductively coupled plasma mass spectrometry. The O2 concentrations and oxidized areas in the rhizosphere significantly increased with increases in the light intensity, air humidity, and atmospheric CO2 concentrations (p < 0.05). The O2 concentration first increased with increasing ambient temperatures, then decreased when the temperature increased from 25 to 32 ℃. The O2 concentration in the rhizosphere was significantly decreased under Cr stress (p < 0.05), with a prolonged response time to the altered ambient temperature. Cr stress led to decreased mobilities of As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Sb, V, W, and Zn in the rhizosphere, which were negatively correlated with the concentrations of O2. These results provide new insights into the role of changes in the O2 concentration induced by the roots of hyperaccumulator plants in controlling the mobility of trace metals in soils.
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Affiliation(s)
- Yao He
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China
| | - Na Ding
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China
| | - Guo Yu
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 541000 Guilin, China.
| | - Geoffrey I Sunahara
- Department of Natural Resource Sciences, McGill University, Montreal, Quebec, Canada
| | - Hua Lin
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 541000 Guilin, China.
| | - Xuehong Zhang
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 541000 Guilin, China
| | - Habib Ullah
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jie Liu
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 541000 Guilin, China
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8
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Yan W, He X, Wu T, Chen M, Lin J, Chen X, Li Q, Li M, Yan Y, Yao Q. A combined study on Vallisneria spiralis and lanthanum modified bentonite to immobilize arsenic in sediments. ENVIRONMENTAL RESEARCH 2023; 216:114689. [PMID: 36323350 DOI: 10.1016/j.envres.2022.114689] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/09/2022] [Accepted: 10/26/2022] [Indexed: 06/16/2023]
Abstract
Submerged plants and lanthanum-modified bentonite (LMB) have important applications for the remediation of contaminated sediments; however, their combined effect on arsenic (As) removal has not been comprehensively evaluated. In this study, the physicochemical properties and changes in soluble As in sediments treated with LMB, Vallisneria spiralis (V. spiralis), and LMB + V. spiralis were observed at three time points (days 15, 35, and 66), and the changes in microbial and As species in sediments on day 66 were analyzed. LMB + V. spiralis treatment was the most effective for As removal. On day 66, the average concentrations of soluble As at a depth of 0-100 mm decreased by 12.71%, 48.81%, and 59.73% following treatment with LMB, V. spiralis, and LMB + V. spiralis, respectively. Further analysis showed that LMB is more effective at removing As(V) than V. spiralis, while V. spiralis is more effective at removing As(III), and the combination of LMB + V. spiralis is more effective for removing both As(III) and As(V) than individual LMB and V. spiralis treatments. LMB + V. spiralis enhanced the transformation of mobile As to Fe2O3/oxyhydroxide-bound As in sediments and the activity of As-oxidizing microorganisms. LMB promoted the growth of V. spiralis and enhanced the removal of As. This study indicates that this combination is an effective method for removing mobile As from sediments, and could effectively inhibit the release of As from sediments to overlying water.
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Affiliation(s)
- Wenming Yan
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China.
| | - Xiangyu He
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China
| | - Tingfeng Wu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Musong Chen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Juan Lin
- School of Geographic Science, Nantong University, Nantong, 226000, China
| | - Xiang Chen
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China
| | - Qi Li
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China
| | - Minjuan Li
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China
| | - Yulin Yan
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China
| | - Qi Yao
- State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing, 210098, China
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9
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Wang C, Bilyera N, Blagodatskaya E, Zhang X, Dippold MA, Dorodnikov M. Keep oxygen in check: An improved in-situ zymography approach for mapping anoxic hydrolytic enzyme activities in a paddy soil. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 850:158118. [PMID: 35987234 DOI: 10.1016/j.scitotenv.2022.158118] [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: 06/18/2022] [Revised: 07/31/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
Paddy soils regularly experience redox oscillations during the wetting and draining stages, yet the effects of short-term presence of oxygen (O2) on in-situ microbial hotspots and enzyme activities in anoxic ecosystems remain unclear. To fill this knowledge gap, we applied soil zymography to localize hotspots and activities of phosphomonoesterase (PME), β-glucosidase (BG), and leucine aminopeptidase (LAP) in three compartments of rice-planted rhizoboxes (top bulk, rooted, and bottom bulk paddy soil) under oxic (+O2) and anoxic (O2) conditions. Short-term (35 min) aeration decreased PME activity by 13-49 %, BG by 4-52 %, and LAP by 12-61 % as compared with O2 in three soil compartments. The percentage of hotspot area was higher by 3-110 % for PME, by 10-60 % for BG, and by 12-158 % for LAP under +O2 vs. O2 conditions depending on a rice growth stage. Irrespective of the aeration conditions, the rhizosphere extent of rice plants for three enzymes was generally greater under higher moisture conditions and at earlier growth stage. Higher O2 sensitivity for the tested enzymes at bottom bulk soil versus other compartments suggested that short-term aeration during conventional zymography may lead to underestimation of nutrient mobilization in subsoil compared to top bulk soil. The intolerance of anaerobic microorganisms against the toxicity of O2 in the cells and the shift of microbial metabolic pathways may explain such a short-term suppression by O2. Our findings, therefore, show that anoxic conditions and soil moisture should be kept during zymography and probably other in-situ soil imaging methods when studying anoxic systems.
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Affiliation(s)
- Chaoqun Wang
- Biogeochemistry of Agroecosystems, University of Goettingen, 37077 Goettingen, Germany.
| | - Nataliya Bilyera
- Geo-Biosphere Interactions, University of Tuebingen, 72076 Tuebingen, Germany
| | - Evgenia Blagodatskaya
- Department of Soil Ecology, Helmholtz Center for Environmental Research, 06120 Halle/Saale, Germany
| | - Xuechen Zhang
- College of Resources and Environment, Northwest A&F University, 712100 Yangling, China
| | - Michaela A Dippold
- Biogeochemistry of Agroecosystems, University of Goettingen, 37077 Goettingen, Germany; Geo-Biosphere Interactions, University of Tuebingen, 72076 Tuebingen, Germany
| | - Maxim Dorodnikov
- Biogeochemistry of Agroecosystems, University of Goettingen, 37077 Goettingen, Germany; Department of Soil Science of Temperate Ecosystems, University of Goettingen, 37077 Goettingen, Germany; Institute of Landscape Ecology, University of Muenster, 48149 Muenster, Germany
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10
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Shiono K, Koshide A, Iwasaki K, Oguri K, Fukao T, Larsen M, Glud RN. Imaging the snorkel effect during submerged germination in rice: Oxygen supply via the coleoptile triggers seminal root emergence underwater. FRONTIERS IN PLANT SCIENCE 2022; 13:946776. [PMID: 35968087 PMCID: PMC9372499 DOI: 10.3389/fpls.2022.946776] [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: 05/18/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Submergence during germination impedes aerobic metabolisms and limits the growth of most higher plants. However, some wetland plants including rice can germinate under submerged conditions. It has long been hypothesized that the first elongating shoot tissue, the coleoptile, acts as a snorkel to acquire atmospheric oxygen (O2) to initiate the first leaf elongation and seminal root emergence. Here, we obtained direct evidence for this hypothesis by visualizing the spatiotemporal O2 dynamics during submerged germination in rice using a planar O2 optode system. In parallel with the O2 imaging, we tracked the anatomical development of shoot and root tissues in real-time using an automated flatbed scanner. Three hours after the coleoptile tip reached the water surface, O2 levels around the embryo transiently increased. At this time, the activity of alcohol dehydrogenase (ADH), an enzyme critical for anaerobic metabolism, was significantly reduced, and the coleorhiza covering the seminal roots in the embryo was broken. Approximately 10 h after the transient burst in O2, seminal roots emerged. A transient O2 burst around the embryo was shown to be essential for seminal root emergence during submerged rice germination. The parallel application of a planar O2 optode system and automated scanning system can be a powerful tool for examining how environmental conditions affect germination in rice and other plants.
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Affiliation(s)
- Katsuhiro Shiono
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui, Japan
| | - Akiko Koshide
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui, Japan
| | - Kazunari Iwasaki
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui, Japan
| | - Kazumasa Oguri
- HADAL and Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
- Research Institute of Global Change, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan
| | - Takeshi Fukao
- Department of Bioscience and Biotechnology, Fukui Prefectural University, Fukui, Japan
| | - Morten Larsen
- HADAL and Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
| | - Ronnie N. Glud
- HADAL and Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
- Department of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, Minato, Japan
- Danish Institute of Advanced Studies, University of Southern Denmark, Odense, Denmark
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11
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Nyer SC, Volkenborn N, Aller RC, Graffam M, Zhu Q, Price RE. Nitrogen transformations in constructed wetlands: A closer look at plant-soil interactions using chemical imaging. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 816:151560. [PMID: 34785218 DOI: 10.1016/j.scitotenv.2021.151560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/24/2021] [Accepted: 11/05/2021] [Indexed: 06/13/2023]
Abstract
Constructed wetlands have long been used for domestic wastewater treatment. Despite the widespread application of constructed wetlands for wastewater remediation, they are still regarded as a black box in terms of the complex biogeochemical processes occurring internally, particularly with respect to plant-soil (and nitrogen) interactions. Additionally, many critical processes pertaining to nitrogen transformations in constructed wetlands are thought to occur in microzones within the rhizosphere, highlighting the need for studies with sub-cm spatial resolution. In this study we coupled nitrogen porewater measurements with chemical imaging to determine spatio-temporal patterns in porewater O2 and pH to assess the extent of plant-induced changes in soil redox dynamics that influence nitrogen biogeochemical cycling during dosed application of nitrogen-rich artificial wastewater. Planar optode imaging revealed extensive O2 fluxes to otherwise anoxic sediment via radial oxygen loss (ROL) from Typha latifolia roots. The contribution of photosynthetic O2 from this plant species was minimal as a strong oxic signal persisted in darkness (diel cycles). NH4+ and NOx- removal were strongly correlated with the extent of oxic and anoxic areas, a function largely attributed to the presence of plants and the associated enhanced microbial communities supported. The distribution of nitrogen species within the Typha rhizosphere exhibited reproducible trends as a function of distance from roots, with concentrations highest close to roots (1-5 mm from root surface) and subsequently decreasing at greater distances. Microscale spatio-temporal redox heterogeneity within the rhizosphere due to ROL imposed by plants promoted nitrogen removal likely by stimulating the coupling between nitrification and denitrification in these systems. Collectively, this study highlights the profound importance of plants in exerting controls on soil conditions and nitrogen cycling in constructed wetland systems. With careful considerations, constructed wetlands designed to promote wetland plants' functions may enhance nitrogen removal and mitigate nitrogen pollution.
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Affiliation(s)
- Samantha C Nyer
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA; The New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY 11794, USA.
| | - Nils Volkenborn
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA; The New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Robert C Aller
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Molly Graffam
- Cornell Cooperative Extension of Suffolk County, Riverhead, NY 11901, USA
| | - Qingzhi Zhu
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA; The New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY 11794, USA
| | - Roy E Price
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA; The New York State Center for Clean Water Technology, Stony Brook University, Stony Brook, NY 11794, USA
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12
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Li C, Ding S, Chen M, Sun Q, Zhang Y, Ma X, Zhong Z, Tsang DCW, Wang Y. Mechanistic insights into trace metal mobilization at the micro-scale in the rhizosphere of Vallisneria spiralis. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150735. [PMID: 34606867 DOI: 10.1016/j.scitotenv.2021.150735] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/28/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
Mobilization of trace metals in the rhizosphere of macrophytes is controlled by root-driven chemical changes, especially the steep gradients of O2 and pH from the rhizosphere to bulk sediments. Here, the O2 and pH dynamics, and the distribution of trace metal, in the rhizosphere of Vallisneria spiralis were obtained using planar optodes and diffusive gradients in thin films, respectively. Radial O2 loss (ROL) and acidification occurred on all visible roots of V. spiralis and exhibited highly spatiotemporal dynamics depending on the root growth and various environmental conditions. Trace metals showed different mobilization mechanisms in the rhizosphere. ROL and produced Fe(III) (oxyhydr)oxides decreased the mobility of Fe, As, Co, V and W in the rhizosphere. However, Mn, Ni and Cu exhibited greater mobility in the rhizosphere than bulk sediments as a result of the oxidation of metal sulfide and proton-induced dissolution of minerals. In particular, Co and Ni presented increased activity at the interface between rhizosphere and bulk sediment, which was attributed to the redox dissolution processes of Fe and Mn as a result of ROL and rhizosphere acidification. These results provide new insights into the roles of macrophyte root-induced O2 and pH changes in controlling trace metal mobility in sediments.
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Affiliation(s)
- Cai Li
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shiming Ding
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Musong Chen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Qin Sun
- College of Environment, Hohai University, Nanjing 210098, China
| | - Yi Zhang
- School of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| | - Xin Ma
- School of Hydrology and Water Resources, Hohai University, Nanjing 210098, China
| | - Zhilin Zhong
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Daniel C W Tsang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China
| | - Yan Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
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13
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Jiménez JDLC, Pellegrini E, Pedersen O, Nakazono M. Radial Oxygen Loss from Plant Roots—Methods. PLANTS 2021; 10:plants10112322. [PMID: 34834684 PMCID: PMC8622749 DOI: 10.3390/plants10112322] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 10/26/2021] [Accepted: 10/26/2021] [Indexed: 11/16/2022]
Abstract
In flooded soils, an efficient internal aeration system is essential for root growth and plant survival. Roots of many wetland species form barriers to restrict radial O2 loss (ROL) to the rhizosphere. The formation of such barriers greatly enhances longitudinal O2 diffusion from basal parts towards the root tip, and the barrier also impedes the entry of phytotoxic compounds produced in flooded soils into the root. Nevertheless, ROL from roots is an important source of O2 for rhizosphere oxygenation and the oxidation of toxic compounds. In this paper, we review the methodological aspects for the most widely used techniques for the qualitative visualization and quantitative determination of ROL from roots. Detailed methodological approaches, practical set-ups and examples of ROL from roots with or without barriers to ROL are included. This paper provides practical knowledge relevant to several disciplines, including plant–soil interactions, biogeochemistry and eco-physiological aspects of roots and soil biota.
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Affiliation(s)
- Juan de la Cruz Jiménez
- Laboratory of Plant Genetics and Breeding, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan;
- Correspondence:
| | - Elisa Pellegrini
- Department of Agricultural, Food, Environmental and Animal Sciences, University of Udine, Via delle Scienze 206, 33100 Udine, Italy;
- The Freshwater Biological Laboratory, Department of Biology, University of Copenhagen, Universitetsparken 4, DK2100 Copenhagen, Denmark;
| | - Ole Pedersen
- The Freshwater Biological Laboratory, Department of Biology, University of Copenhagen, Universitetsparken 4, DK2100 Copenhagen, Denmark;
- UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, Perth, WA 6009, Australia
| | - Mikio Nakazono
- Laboratory of Plant Genetics and Breeding, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan;
- UWA School of Agriculture and Environment, Faculty of Science, The University of Western Australia, Perth, WA 6009, Australia
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14
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Li C, Ding S, Ma X, Chen M, Zhong Z, Zhang Y, Ren M, Zhang M, Yang L, Rong N, Wang Y. O 2 distribution and dynamics in the rhizosphere of Phragmites australis, and implications for nutrient removal in sediments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 287:117193. [PMID: 33989948 DOI: 10.1016/j.envpol.2021.117193] [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: 12/28/2020] [Revised: 04/08/2021] [Accepted: 04/17/2021] [Indexed: 06/12/2023]
Abstract
Root-triggered microscale variations in O2 distribution in the rhizosphere of young Phragmites australis are important for nutrient removal in sediments. In this study, the micro-scale O2 dynamics and the small-scale changes of soluble reactive phosphorus (SRP) and ammonium (NH4+) in the rhizosphere of P. australis were investigated using planar optodes and high-resolution dialysis (HR-Peeper), respectively. Results suggested that root O2 leakage has a highly variable distribution depending on the stage of root growth, the site of O2 leakage gradually shift from the entire emerging main roots to the main root tip and subsequently shifted the emerging lateral roots. The O2 concentration increased in the rhizosphere with increasing light intensity and O2 levels in the overlying water. Continuous O2 release from the lateral roots causes the formation of iron plaque on the surface of lateral roots, which reduce the mobility of P by adsorption of iron plaque in the rhizosphere. The oscillation of oxic-anoxic root zones improves nitrogen removal through the processes of anammox, heterotrophic denitrification and nitrification. This work from the micro-scale demonstrates that the O2 concentration is the spatio-temporal variations in the rhizosphere, and it presents an important role for nutrient removal in sediments.
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Affiliation(s)
- Cai Li
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shiming Ding
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Xin Ma
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; School of Water Conservancy and Environment, University of Jinan, Jinan, 250022, China
| | - Musong Chen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Zhilin Zhong
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yi Zhang
- School of Hydrology and Water Resources, Hohai University, Nanjing, 210098, China
| | - Mingyi Ren
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Min Zhang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; School of Water Conservancy and Environment, University of Jinan, Jinan, 250022, China
| | - Liyuan Yang
- School of Water Conservancy and Environment, University of Jinan, Jinan, 250022, China
| | - Nan Rong
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510530, China
| | - Yan Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China; Nanjing EasySensor Environmental Technology Co., Ltd, Nanjing, 210018, China
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15
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Zhao Z, Ozcan EE, VanArsdale E, Li J, Kim E, Sandler AD, Kelly DL, Bentley WE, Payne GF. Mediated Electrochemical Probing: A Systems-Level Tool for Redox Biology. ACS Chem Biol 2021; 16:1099-1110. [PMID: 34156828 DOI: 10.1021/acschembio.1c00267] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Biology uses well-known redox mechanisms for energy harvesting (e.g., respiration), biosynthesis, and immune defense (e.g., oxidative burst), and now we know biology uses redox for systems-level communication. Currently, we have limited abilities to "eavesdrop" on this redox modality, which can be contrasted with our abilities to observe and actuate biology through its more familiar ionic electrical modality. In this Perspective, we argue that the coupling of electrochemistry with diffusible mediators (electron shuttles) provides a unique opportunity to access the redox communication modality through its electrical features. We highlight previous studies showing that mediated electrochemical probing (MEP) can "communicate" with biology to acquire information and even to actuate specific biological responses (i.e., targeted gene expression). We suggest that MEP may reveal an extent of redox-based communication that has remained underappreciated in nature and that MEP could provide new technological approaches for redox biology, bioelectronics, clinical care, and environmental sciences.
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Affiliation(s)
- Zhiling Zhao
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, Maryland 20742, United States
- Robert E. Fischell Biomedical Device Institute, University of Maryland, College Park, Maryland 20742, United States
| | - Evrim E. Ozcan
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, Maryland 20742, United States
| | - Eric VanArsdale
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, Maryland 20742, United States
- Robert E. Fischell Biomedical Device Institute, University of Maryland, College Park, Maryland 20742, United States
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Jinyang Li
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, Maryland 20742, United States
- Robert E. Fischell Biomedical Device Institute, University of Maryland, College Park, Maryland 20742, United States
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Eunkyoung Kim
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, Maryland 20742, United States
- Robert E. Fischell Biomedical Device Institute, University of Maryland, College Park, Maryland 20742, United States
| | - Anthony D. Sandler
- Department of General and Thoracic Surgery, Children’s National Hospital, Washington, D.C. 20010, United States
| | - Deanna L. Kelly
- Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, Maryland 21228, United States
| | - William E. Bentley
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, Maryland 20742, United States
- Robert E. Fischell Biomedical Device Institute, University of Maryland, College Park, Maryland 20742, United States
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland 20742, United States
| | - Gregory F. Payne
- Institute for Bioscience & Biotechnology Research, University of Maryland, College Park, Maryland 20742, United States
- Robert E. Fischell Biomedical Device Institute, University of Maryland, College Park, Maryland 20742, United States
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16
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Koop-Jakobsen K, Meier RJ, Mueller P. Plant-Mediated Rhizosphere Oxygenation in the Native Invasive Salt Marsh Grass Elymus athericus. FRONTIERS IN PLANT SCIENCE 2021; 12:669751. [PMID: 34177984 PMCID: PMC8222977 DOI: 10.3389/fpls.2021.669751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 05/03/2021] [Indexed: 06/13/2023]
Abstract
In the last decades, the spread of Elymus athericus has caused significant changes to the plant community composition and ecosystem services of European marshes. The distribution of E. athericus was typically limited by soil conditions characteristic for high marshes, such as low flooding frequency and high soil aeration. However, recently the spread of E. athericus has begun to also include low-marsh environments. A high-marsh ecotype and a low-marsh ecotype of E. athericus have been described, where the latter possess habitat-specific phenotypic traits facilitating a better adaption for inhabiting low-marsh areas. In this study, planar optodes were applied to investigate plant-mediated sediment oxygenation in E. athericus, which is a characteristic trait for marsh plants inhabiting frequently flooded environments. Under waterlogged conditions, oxygen (O2) was translocated from aboveground sources to the roots, where it leaked out into the surrounding sediment generating oxic root zones below the sediment surface. Oxic root zones were clearly visible in the optode images, and no differences were found in the O2-leaking capacity between ecotypes. Concentration profiles measured perpendicular to the roots revealed that the radius of the oxic root zones ranged from 0.5 to 2.6 mm measured from the root surface to the bulk anoxic sediment. The variation of oxic root zones was monitored over three consecutive light-dark cycles (12 h/12 h). The O2 concentration of the oxic root zones was markedly reduced in darkness, yet the sediment still remained oxic in the immediate vicinity of the roots. Increased stomatal conductance improving the access to atmospheric O2 as well as photosynthetic O2 production are likely factors facilitating the improved rhizosphere oxygenation during light exposure of the aboveground biomass. E. athericus' capacity to oxygenate its rhizosphere is an inheritable trait that may facilitate its spread into low-marsh areas. Furthermore, this trait makes E. athericus a highly competitive species in marshes facing the effects of accelerated sea-level rise, where waterlogged sediment conditions could become increasingly pronounced.
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Affiliation(s)
- Ketil Koop-Jakobsen
- Wadden Sea Station, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), List/Sylt, Germany
| | | | - Peter Mueller
- Institute of Soil Science, Center for Earth System Research and Sustainability, Universität Hamburg, Hamburg, Germany
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17
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Ejiri M, Fukao T, Miyashita T, Shiono K. A barrier to radial oxygen loss helps the root system cope with waterlogging-induced hypoxia. BREEDING SCIENCE 2021; 71:40-50. [PMID: 33762875 PMCID: PMC7973497 DOI: 10.1270/jsbbs.20110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 12/14/2020] [Indexed: 05/04/2023]
Abstract
Internal aeration is crucial for root growth under waterlogged conditions. Many wetland plants have a structural barrier that impedes oxygen leakage from the basal part of roots called a radial oxygen loss (ROL) barrier. ROL barriers reduce the loss of oxygen transported via the aerenchyma to the root tips, enabling long-distance oxygen transport for cell respiration at the root tip. Because the root tip does not have an ROL barrier, some of the transferred oxygen is released into the waterlogged soil, where it oxidizes and detoxifies toxic substances (e.g., sulfate and Fe2+) around the root tip. ROL barriers are located at the outer part of roots (OPRs). Their main component is thought to be suberin. Suberin deposits may block the entry of potentially toxic compounds in highly reduced soils. The amount of ROL from the roots depends on the strength of the ROL barrier, the length of the roots, and environmental conditions, which causes spatiotemporal changes in the root system's oxidization pattern. We summarize recent achievements in understanding how ROL barrier formation is regulated and discuss opportunities for breeding waterlogging-tolerant crops.
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Affiliation(s)
- Masato Ejiri
- Graduate School of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji, Fukui 910-1195,
Japan
| | - Takeshi Fukao
- Graduate School of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji, Fukui 910-1195,
Japan
| | - Tomoki Miyashita
- Graduate School of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji, Fukui 910-1195,
Japan
| | - Katsuhiro Shiono
- Graduate School of Bioscience and Biotechnology, Fukui Prefectural University, 4-1-1 Matsuoka-Kenjojima, Eiheiji, Fukui 910-1195,
Japan
- Corresponding author (e-mail: )
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18
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Ultee E, Zhong X, Shitut S, Briegel A, Claessen D. Formation of wall-less cells in Kitasatospora viridifaciens requires cytoskeletal protein FilP in oxygen-limiting conditions. Mol Microbiol 2020; 115:1181-1190. [PMID: 33278050 PMCID: PMC8359286 DOI: 10.1111/mmi.14662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 12/01/2020] [Accepted: 12/01/2020] [Indexed: 02/07/2023]
Abstract
The cell wall is considered an essential component for bacterial survival, providing structural support, and protection from environmental insults. Under normal growth conditions, filamentous actinobacteria insert new cell wall material at the hyphal tips regulated by the coordinated activity of cytoskeletal proteins and cell wall biosynthetic enzymes. Despite the importance of the cell wall, some filamentous actinobacteria can produce wall‐deficient S‐cells upon prolonged exposure to hyperosmotic stress. Here, we performed cryo‐electron tomography and live cell imaging to further characterize S‐cell extrusion in Kitasatospora viridifaciens. We show that exposure to hyperosmotic stress leads to DNA compaction, membrane and S‐cell extrusion, and thinning of the cell wall at hyphal tips. Additionally, we find that the extrusion of S‐cells is abolished in a cytoskeletal mutant strain that lacks the intermediate filament‐like protein FilP. Furthermore, micro‐aerobic culturing promotes the formation of S‐cells in the wild type, but the limited oxygen still impedes S‐cell formation in the ΔfilP mutant. These results demonstrate that S‐cell formation is stimulated by oxygen‐limiting conditions and dependent on functional cytoskeleton remodeling.
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Affiliation(s)
- Eveline Ultee
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands.,Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Xiaobo Zhong
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands.,Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Shraddha Shitut
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands.,Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Ariane Briegel
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands.,Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
| | - Dennis Claessen
- Department of Molecular Biotechnology, Institute of Biology, Leiden University, Leiden, The Netherlands.,Centre for Microbial Cell Biology, Leiden University, Leiden, The Netherlands
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19
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Scholz VV, Müller H, Koren K, Nielsen LP, Meckenstock RU. The rhizosphere of aquatic plants is a habitat for cable bacteria. FEMS Microbiol Ecol 2020; 95:5485638. [PMID: 31054245 PMCID: PMC6510695 DOI: 10.1093/femsec/fiz062] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 05/03/2019] [Indexed: 11/15/2022] Open
Abstract
Cable bacteria belonging to the family Desulfobulbaceae couple sulfide oxidation and oxygen reduction by long-distance electron transfer over centimeter distances in marine and freshwater sediments. In such habitats, aquatic plants can release oxygen into the rhizosphere. Hence, the rhizosphere constitutes an ideal habitat for cable bacteria, which have been reported on seagrass roots recently. Here, we employ experimental approaches to investigate activity, abundance, and spatial orientation of cable bacteria next to the roots of the freshwater plant Littorella uniflora. Fluorescence in situ hybridization (FISH), in combination with oxygen-sensitive planar optodes, demonstrated that cable bacteria densities are enriched at the oxic–anoxic transition zone next to roots compared to the bulk sediment in the same depth. Scanning electron microscopy showed cable bacteria along root hairs. Electric potential measurements showed a lateral electric field over centimeters from the roots, indicating cable bacteria activity. In addition, FISH revealed that cable bacteria were present in the rhizosphere of Oryza sativa (rice), Lobelia cardinalis and Salicornia europaea. Hence, the interaction of cable bacteria with aquatic plants of different growth forms and habitats indicates that the plant root–cable bacteria interaction might be a common property of aquatic plant rhizospheres.
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Affiliation(s)
- Vincent V Scholz
- Biofilm Centre, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany.,Center for Electromicrobiology, Aarhus University, Ny Munkegade 116, DK-8000 Aarhus C, Denmark
| | - Hubert Müller
- Biofilm Centre, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
| | - Klaus Koren
- Aarhus University Centre for Water Technology, Section for Microbiology, Department of Bioscience, Aarhus University, Ny Munkegade 116, DK-8000 Aarhus C, Denmark
| | - Lars Peter Nielsen
- Center for Electromicrobiology, Aarhus University, Ny Munkegade 116, DK-8000 Aarhus C, Denmark
| | - Rainer U Meckenstock
- Biofilm Centre, University of Duisburg-Essen, Universitätsstr. 5, 45141 Essen, Germany
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20
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Cable bacteria reduce methane emissions from rice-vegetated soils. Nat Commun 2020; 11:1878. [PMID: 32313021 PMCID: PMC7171082 DOI: 10.1038/s41467-020-15812-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 03/30/2020] [Indexed: 11/25/2022] Open
Abstract
Methane is the second most important greenhouse gas after carbon dioxide and approximately 11% of the global anthropogenic methane emissions originate from rice fields. Sulfate amendment is a mitigation strategy to reduce methane emissions from rice fields because sulfate reducers and methanogens compete for the same substrates. Cable bacteria are filamentous bacteria known to increase sulfate levels via electrogenic sulfide oxidation. Here we show that one-time inoculation of rice-vegetated soil pots with cable bacteria increases the sulfate inventory 5-fold, which leads to the reduction of methane emissions by 93%, compared to control pots lacking cable bacteria. Promoting cable bacteria in rice fields by enrichment or sensible management may thus become a strategy to reduce anthropogenic methane emissions. Rice paddies are a major source of the Earth’s atmospheric methane, making these important food crops potent contributors to greenhouse gas emissions. Here the authors show that inoculation of paddies with a particular bacterium could significantly curb methane production.
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21
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Ma H, Gao F, Zhang X, Cui B, Liu Y, Li Z. Formation of iron plaque on roots of Iris pseudacorus and its consequence for cadmium immobilization is impacted by zinc concentration. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 193:110306. [PMID: 32109586 DOI: 10.1016/j.ecoenv.2020.110306] [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: 10/18/2019] [Revised: 01/30/2020] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
The impact of iron plaque (IP) on bioavailability of heavy metals to plants has been well documented, but the role of zinc (Zn) in modulating the associated processes remains elusive. We took Iris pseudacorus used in wetland for remediating Cd-contaminated water as an example and systematically studied the combined influence of Cd and Zn concentration on formation of IP and its consequence for immobilization and plant uptake of Cd. The experiment was conducted in hydroponic culture and in each treatment, we measured the physiological traits, activity of antioxidant enzymes (SOD, POD, CAT), mass of the IP, as well as the Cd content in both plant tissues and IP. The results showed that increasing Cd concentration resulted in a steady reduction in IP while the impact of zinc on IP was complicated and appeared to be coupled with Cd. When the Cd concentration was low (0.5 mg L-1 measured as CdCl2 2·5H2O) increasing Zn concentration reduced IP, while when the Cd concentration was increased to 5 mg L-1 increasing zinc concentration led to an increase in IP mass first followed by a decline after Zn concentration exceeded 100 mg L-1 (measured as ZnSO4·7H2O). The change in IP as affected by Zn had a strong consequence for immobilization and plant uptake of Cd. When Cd concentration was low, the IP was comparatively abundant and hence adsorbed most Cd. In contrast, when Cd concentration was high, the IP reduced and the amount of Cd taken up by plant roots and translocated to shoots and leaves increased. Both Cd immobilization and its plant uptake were modulated by Zn concentration. At low Cd concentration the combined Cd immobilized and taken up by plant peaked when the Zn concentration was 50 mg L-1, while at high Cd concentration the combined Cd reached maxima when theZn concentration was 100 mg L-1. The activity of the antioxidant enzymes changed significantly with Zn rather than with Cd. Regardless of Cd concentration, the activity of all three antioxidant enzymes increased first with zinc concentration before declining when the Zn concentration exceeded approximately 100 mg L-1 in all treatments, comparable with the change in immobilization and plant uptake of Cd as the Zn concentration increased. SEM analysis did prove the formation and variation of IP on the root surface of Iris pseudacorus in different treatments. We also found that the plant developed a survival strategy by scarifying its leaves with high Cd content. The results presented in this paper has wide implications as it revealed that care needs to be taken in applying Zn to enhance Cd immobilization and its plant uptake as exceeding the optimal application rate might reduce remediating efficiency rather than increase it.
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Affiliation(s)
- Huanhuan Ma
- Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang, Henan Province, 453002, China.
| | - Feng Gao
- Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang, Henan Province, 453002, China.
| | - Xiaoxian Zhang
- Sustiainable Agriculture Sciences, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom.
| | - Bingjian Cui
- Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang, Henan Province, 453002, China.
| | - Yuan Liu
- Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang, Henan Province, 453002, China.
| | - Zhongyang Li
- Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang, Henan Province, 453002, China.
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22
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Yin DX, Fang W, Guan DX, Williams PN, Moreno-Jimenez E, Gao Y, Zhao FJ, Ma LQ, Zhang H, Luo J. Localized Intensification of Arsenic Release within the Emergent Rice Rhizosphere. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:3138-3147. [PMID: 31968168 DOI: 10.1021/acs.est.9b04819] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Behavior of trace elements in flooded/lowland rice soils is controlled by root-zone iron oxidation. Insoluble iron species bind/capture toxic elements, i.e., arsenic. However, it was recently observed that within this territory of arsenic immobilization lies a zone of prolific iron release, accompanied by a significant flux of arsenic in close proximity to rice root apices. Questions still remain on how common this phenomenon is and whether the chemical imaging approaches or soils/cultivars used influence this event. Here, three types of ultrathin/high-resolution diffusive gradient in thin films (DGT) substrates were integrated with oxygen planar optodes in a multilayer system, providing two-dimensional mapping of solute fluxes. The three DGT approaches revealed a consistent/overlapping spatial distribution with localized flux maxima for arsenic, which occurred in all experiments, concomitant with iron mobilization. Soil/porewater microsampling within the rhizosphere revealed no significant elevation in the solid phase's total iron and arsenic concentrations between aerobic and anaerobic zones. Contrary to arsenic, phosphorus bioavailability was shown to decrease in the arsenic/iron flux maxima. Rice roots, in addition to their role in nutrient acquisition, also perform a key sensory function. Flux maxima represent a significant departure from the chemical conditions of the bulk/field environment, but our observations of a complete rhizosphere reveal a mixed mode of root-soil interactions.
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Affiliation(s)
- Dai-Xia Yin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Wen Fang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Dong-Xing Guan
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
| | - Paul N Williams
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, Northern Ireland, United Kingdom
| | - Eduardo Moreno-Jimenez
- Department of Agricultural and Food Chemistry, Universidad Autónoma de Madrid, Madrid E-28049, Spain
| | - Yue Gao
- Analytical, Environmental and Geochemistry (AMGC), Faculty of Science, Vrije Universiteit Brussel, Pleinlaan 2, Brussels 1050, Belgium
| | - Fang-Jie Zhao
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China
| | - Lena Q Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
- Soil and Water Science Department, University of Florida, Gainesville, Florida 32611, United States
| | - Hao Zhang
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, U.K
| | - Jun Luo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
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23
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Murphy T, Irvine K, Phan K, Lean D, Wilson K. Environmental and Health Implications of the Correlation Between Arsenic and Zinc Levels in Rice from an Arsenic-Rich Zone in Cambodia. J Health Pollut 2019; 9:190603. [PMID: 31259079 PMCID: PMC6555249 DOI: 10.5696/2156-9614-9.22.190603] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 04/01/2019] [Indexed: 04/29/2023]
Abstract
BACKGROUND In parts of Cambodia, irrigation of rice with groundwater results in arsenic accumulation in soils and rice, leading to health concerns associated with rice consumption. In Bangladesh and China, low zinc levels in rice have been found in regions where arsenic levels in rice are high. Furthermore, there have been claims that zinc deficiency is responsible for stunting of children in Cambodia. There are limited data on zinc in Cambodian rice, but in rural Asia, rice is the major source of zinc. OBJECTIVES To provide a preliminary evaluation of the zinc content in rice grain in Preak Russey, an area with elevated levels of arsenic. The importance of zinc in rice for infants was also assessed. METHODS Rice cultivation was evaluated in sixty farms along the Mekong River in Cambodia. Analyses for metals, total arsenic, and arsenic species in the water and rice were conducted at the University of Ottawa, Canada by inductively coupled plasma - mass spectrometry. Analysis of total zinc and arsenic in soils were analyzed in Phnom Penh using X-ray fluorescence spectrometry (XRF). Total zinc in rice was also measured by XRF analysis. RESULTS Rice in the Preak Russey area contained zinc with ½ to ¼ of the 1987 Codex standard for rice in Infant Formula. Moreover, our average zinc concentration in rice samples was less than a third that recommended for zinc fortification in rice by the United Nations World Food Programme. There was a significant (α=0.05) negative correlation between the arsenic and zinc content of rice with the lowest zinc levels occurring near the irrigation wells, the source of arsenic. There was a significantly higher content of zinc in rice from farms that fertilized with cow manure. CONCLUSIONS Handheld XRF spectrometers are useful tools for detection of zinc levels in rice. The potential for zinc deficiency in farmers in areas of Cambodia with arsenic toxicity is high. COMPETING INTERESTS The authors declare no competing financial interests.
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Affiliation(s)
- Tom Murphy
- International University, Phnom Penh, Cambodia
| | - Kim Irvine
- Nanyang Technological University, Singapore
| | | | - David Lean
- Lean Environmental, Apsley, Ontario, Canada
| | - Ken Wilson
- Texas State University, San Marcos, Texas, USA
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24
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Sakpirom J, Kantachote D, Siripattanakul-Ratpukdi S, McEvoy J, Khan E. Simultaneous bioprecipitation of cadmium to cadmium sulfide nanoparticles and nitrogen fixation by Rhodopseudomonas palustris TN110. CHEMOSPHERE 2019; 223:455-464. [PMID: 30784752 DOI: 10.1016/j.chemosphere.2019.02.051] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 02/05/2019] [Accepted: 02/09/2019] [Indexed: 05/27/2023]
Abstract
This study investigated the abilities of a purple non-sulfur bacterium, Rhodopseudomonas palustris TN110 to bioremediate cadmium through the biosynthesis of CdS nanoparticles and to fix nitrogen simultaneously. Under microaerobic-light conditions, R. palustris TN110 synthesized CdS nanoparticles. The produced CdS nanoparticles had a spherical shape and an average size of 4.85 nm. The Fourier transform infrared spectrum of the nanoparticles reveals the carbonyl groups, bending vibrations of the amide I and II bands of proteins, and CN stretching vibrations of aromatic and aliphatic amines. These bands and groups suggest protein capping/binding on the surface of the nanoparticles. R. palustris TN110 converted 25.61% of 0.2 mM CdCl2 to CdS nanoparticles under optimal conditions (pH 7.5, 30 °C and 3000 lux). The half maximal inhibitory concentration (IC50) value of the produced CdS nanoparticles was 1.76 mM. The produced CdS nanoparticles at IC50 up-regulated two genes associated with nitrogen fixation: Mo-Fe nitrogenase gene (nifH) and V-Fe nitrogenase gene (vnfG) at 2.83 and 2.27 fold changes, respectively. On the contrary, the produced CdS nanoparticles slightly down-regulated Fe-Fe nitrogenase gene (anfG). The amounts of ammonia released by the strain support the gene expression results. R. palustris TN110 has great potential to serve concurrently as a cadmium bioremediation agent and a nitrogen fixer. The strain could be beneficial to paddy fields that are contaminated with Cd through run off from mining and chemical fertilizer applications.
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Affiliation(s)
- Jakkapan Sakpirom
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, 90112, Thailand.
| | - Duangporn Kantachote
- Department of Microbiology, Faculty of Science, Prince of Songkla University, Hat Yai, 90112, Thailand; Center of Excellence on Hazardous Substance Management (HSM), Bangkok, 10330, Thailand.
| | - Sumana Siripattanakul-Ratpukdi
- Center of Excellence on Hazardous Substance Management (HSM), Bangkok, 10330, Thailand; Department of Environmental Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen, 40002, Thailand.
| | - John McEvoy
- Department of Microbiological Sciences, North Dakota State University, Fargo, ND 58108, USA.
| | - Eakalak Khan
- Department of Civil and Environmental Engineering and Construction, University of Nevada, Las Vegas, NV 89154, USA.
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25
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Koren K, Moßhammer M, Scholz VV, Borisov SM, Holst G, Kühl M. Luminescence Lifetime Imaging of Chemical Sensors-A Comparison between Time-Domain and Frequency-Domain Based Camera Systems. Anal Chem 2019; 91:3233-3238. [PMID: 30758940 DOI: 10.1021/acs.analchem.8b05869] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Luminescence lifetime based imaging is still the most reliable method for generating chemical images using chemical sensor technology. However, only few commercial systems are available that enable imaging lifetimes within the relevant nanosecond to microsecond range. In this technical note we compare the performance of an older time-domain (TD) based camera system with a frequency-domain (FD) based camera system regarding their measuring characteristics and applicability for O2 and pH imaging in environmental samples and with different indicator dye systems emitting in the visible and near-infrared part of the spectrum. We conclude that the newly introduced FD imaging system delivers comparable if not better results than its predecessor, now enabling robust and simple chemical imaging based on FD luminescence lifetime measurements.
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Affiliation(s)
- Klaus Koren
- Aarhus University Centre for Water Technology, Section for Microbiology, Department of Bioscience , Aarhus University , Ny Munkegade , DK-8000 Aarhus C , Denmark
| | - Maria Moßhammer
- Marine Biological Section, Department of Biology , University of Copenhagen , Strandpromenaden 5 , DK-3000 Helsingør , Denmark
| | - Vincent V Scholz
- Center for Electromicrobiology , Aarhus University , DK-8000 Aarhus , Denmark
| | - Sergey M Borisov
- Institute of Analytical Chemistry and Food Chemistry , Graz University of Technology , Stremayrgasse 9 , AT-8010 Graz , Austria
| | | | - Michael Kühl
- Marine Biological Section, Department of Biology , University of Copenhagen , Strandpromenaden 5 , DK-3000 Helsingør , Denmark.,Climate Change Cluster , University of Technology Sydney , Ultimo , NSW 2007 , Australia
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26
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Moßhammer M, Brodersen KE, Kühl M, Koren K. Nanoparticle- and microparticle-based luminescence imaging of chemical species and temperature in aquatic systems: a review. Mikrochim Acta 2019; 186:126. [PMID: 30680465 DOI: 10.1007/s00604-018-3202-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 12/20/2018] [Indexed: 11/25/2022]
Abstract
Most aquatic systems rely on a multitude of biogeochemical processes that are coupled with each other in a complex and dynamic manner. To understand such processes, minimally invasive analytical tools are required that allow continuous, real-time measurements of individual reactions in these complex systems. Optical chemical sensors can be used in the form of fiber-optic sensors, planar sensors, or as micro- and nanoparticles (MPs and NPs). All have their specific merits, but only the latter allow for visualization and quantification of chemical gradients over 3D structures. This review (with 147 references) summarizes recent developments mainly in the field of optical NP sensors relevant for chemical imaging in aquatic science. The review encompasses methods for signal read-out and imaging, preparation of NPs and MPs, and an overview of relevant MP/NP-based sensors. Additionally, examples of MP/NP-based sensors in aquatic systems such as corals, plant tissue, biofilms, sediments and water-sediment interfaces, marine snow and in 3D bioprinting are given. We also address current challenges and future perspectives of NP-based sensing in aquatic systems in a concluding section. Graphical abstract ᅟ.
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Affiliation(s)
- Maria Moßhammer
- Marine Biological Section, Department of Biology, University of Copenhagen, 3000, Helsingør, Denmark
| | - Kasper Elgetti Brodersen
- Marine Biological Section, Department of Biology, University of Copenhagen, 3000, Helsingør, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, 3000, Helsingør, Denmark.
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
| | - Klaus Koren
- Aarhus University Center for Water Technology, Department of Bioscience - Microbiology, Aarhus University, 8000, Aarhus, Denmark.
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27
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Shi X, Fang W, Tang N, Williams PN, Hu X, Liu Z, Yin D, Ma LQ, Luo J. In Situ Selective Measurement of Se IV in Waters and Soils: Diffusive Gradients in Thin-Films with Bi-Functionalized Silica Nanoparticles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:14140-14148. [PMID: 30431268 DOI: 10.1021/acs.est.8b03671] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The speciation of selenium (Se) controls its fate and behavior, determining both its biological and environmental activities. However, in situ monitoring of SeIV presents a significant challenge due to its sensitivity to redox change. A novel diffusive gradients in thin films (DGT) technique containing mercapto-, amino-bifunctionalized SBA15 mesoporous silica nanoparticles was developed and evaluated in a series of laboratory and field deployment tests. The SBA-DGT exhibited a linear accumulation of SeIV ( r2 > 0.997) over a 72 h deployment, with negligible accumulation of SeVI(<5%). Consistent prediction of SeIV occurred within ionic strength and pH ranges of 0.1-200 mmol L-1 and 3.6-8, respectively. Limits of detection of the SBA-DGT were 0.03 μg SeIV L-1, which is suitable for natural waters. Moreover, the properties of the bifunctionalized SBA15 enable it to be fabricated within ultrathin (0.05 mm) gel layers for use in conjunction with O2 planar optode imaging. This new sandwich sensor technology with SBA-DGT was validated by mapping the two-dimensional distribution of SeIV and oxygen simultaneously in rice rhizospheres. This study shows that SBA-DGT provides a selective measurement of SeIV in situ, demonstrating its potential for both environmental monitoring and as a research tool for improving our understanding of Se biogeochemical processes.
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Affiliation(s)
- Xinyao Shi
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Jiangsu 210023 , China
| | - Wen Fang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Jiangsu 210023 , China
| | - Ni Tang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Jiangsu 210023 , China
| | - Paul N Williams
- Institute for Global Food Security, School of Biological Sciences , Queen's University Belfast , Belfast BT9 7BL , United Kingdom
| | - Xuan Hu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Jiangsu 210023 , China
| | - Zhaodong Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Jiangsu 210023 , China
| | - Daixia Yin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Jiangsu 210023 , China
| | - Lena Q Ma
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Jiangsu 210023 , China
- Soil and Water Science Department , University of Florida , Gainesville , Florida 32611 , United States
| | - Jun Luo
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Jiangsu 210023 , China
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28
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Han C, Ren J, Wang Z, Yang S, Ke F, Xu D, Xie X. Characterization of phosphorus availability in response to radial oxygen losses in the rhizosphere of Vallisneria spiralis. CHEMOSPHERE 2018; 208:740-748. [PMID: 29902758 DOI: 10.1016/j.chemosphere.2018.05.180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 05/23/2018] [Accepted: 05/29/2018] [Indexed: 06/08/2023]
Abstract
The viewpoint that radial oxygen loss (ROL) of submerged macrophytes induces changes in redox conditions and the associated phosphorus (P) availability has been indirectly confirmed at larger spatial scales using conventional, destructive techniques. However, critical information about microniches has largely been overlooked due to the lack of satisfactory in situ mapping technologies. In this study, we deployed a recently developed hybrid sensor in the rhizosphere of Vallisneria spiralis (V. spiralis) during two vegetation periods to provide 2-D imaging of the spatiotemporal co-distribution of oxygen (O2) and P from a fixed observation point. Overall, the images of O2 and P showed a high degree of spatiotemporal heterogeneity throughout the rhizosphere at the sub-mm scale. A clear decrease in the P mobilization corresponded well to the steep O2 enhancement within a 2-mm-thick zone around younger V. spiralis root, indicating a significant coupling relationship between ROL and P availability. Surprisingly, despite significant diurnal shifts in ROL along the older V. spiralis roots, P availability did not fluctuate in a substantial part of the rhizosphere throughout the day; however, ROL increased the P immobilization significantly by changing the redox gradients at the outer rhizosphere. This study clearly demonstrates how continuous ROL of V. spiralis can play a major role in regulating P availability within the rhizosphere. The premise behind this statement is the discovery of how this continuous ROL can lead to the formation of three distinctive redox landscapes in the rooting sediment (oxic, suboxic, or anaerobic layers).
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Affiliation(s)
- Chao Han
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Jinghua Ren
- Geological Survey of Jiangsu Province, Nanjing, 210018, China
| | - Zhaode Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Shika Yang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Fan Ke
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Di Xu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Xianchuan Xie
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093, China.
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29
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Huang G, Ding C, Hu Z, Cui C, Zhang T, Wang X. Topdressing iron fertilizer coupled with pre-immobilization in acidic paddy fields reduced cadmium uptake by rice (Oryza sativa L.). THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 636:1040-1047. [PMID: 29913566 DOI: 10.1016/j.scitotenv.2018.04.369] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 04/20/2018] [Accepted: 04/26/2018] [Indexed: 06/08/2023]
Abstract
Soil cadmium (Cd) contamination has become a serious problem in China. This study was conducted to test the effects of basal application of hydrated lime and iron fertilizer alone or together and topdressing of iron fertilizer at the tillering stage alone or coupled with basal application of hydrated lime, on reducing the accumulation of Cd in brown rice grown in an acidic paddy field slightly contaminated with Cd. The results showed that Cd in brown rice (BR-Cd) was dependent on not only the pH increase and CaCl2-extractable Cd reduction in the soil due to lime amendment but also Cd sequestration by the iron plaque on root surfaces. However, lime significantly decreased the amounts of Fe and Cd in the iron plaque on the surface of rice root. Topdressing of ferrous sulfate at the tillering stage resulted in the highest Fe and Cd sequestration in the iron plaque. Compared with the control (0.71 mg kg-1 BR-Cd), the basal application of lime and ferrous sulfate alone or together reduced BR-Cd by 45.8%, 18.3%, and 53.1%, respectively; topdressing of ferrous sulfate alone reduced BR-Cd by 23.6%, and topdressing of ferrous sulfate at the tillering stage coupled with basal application of lime yielded the lowest BR-Cd level with a 74.6% reduction. This result was further confirmed by field experiments at two sites in the following year.
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Affiliation(s)
- Gaoxiang Huang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Changfeng Ding
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Zhaoyun Hu
- Agricultural Technology Extension Center of Yi'an District, Tongling 244100, China
| | - Caihong Cui
- Agricultural Technology Extension Center of Yi'an District, Tongling 244100, China
| | - Taolin Zhang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
| | - Xingxiang Wang
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; Ecological Experimental Station of Red Soil, Chinese Academy of Sciences, Yingtan 335211, China.
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30
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Rodeghiero M, Rubol S, Bellin A, Turco E, Molinatto G, Gianelle D, Pertot I. High Resolution Assessment of Spatio-Temporal Changes in O 2 Concentration in Root-Pathogen Interaction. Front Microbiol 2018; 9:1491. [PMID: 30026738 PMCID: PMC6041416 DOI: 10.3389/fmicb.2018.01491] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 06/15/2018] [Indexed: 01/19/2023] Open
Abstract
Fusarium wilt, caused by the fungus Fusarium oxysporum f. sp. lycopersici (Fol), is one of the most destructive soil-borne diseases of tomatoes. Infection takes place on the roots and the process starts with contact between the fungus and the roots hairs. To date, no detailed studies are available on metabolic activity in the early stages of the Fol and tomato root interaction. Spatial and temporal patterns of oxygen consumption could provide new insights into the dynamics of early colonization. Here, we combined planar optodes and spatial analysis to assess how tomato roots influence the metabolic activity and growth patterns of Fol. The results shows that the fungal metabolism, measured as oxygen consumption, increases within a few hours after the inoculation. Statistical analysis revealed that the fungus tends to growth toward the root, whereas, when the root is not present, the single elements of the fungus move with a Brownian motion (random). The combination of planar optodes and spatial analysis is a powerful new tool for assessing temporal and spatial dynamics in the early stages of root-pathogen interaction.
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Affiliation(s)
- Mirco Rodeghiero
- Sustainable Agro-Ecosystems and Bioresources Department, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Simonetta Rubol
- Energy Resources Engineering, Stanford University, Stanford, CA, United States
| | - Alberto Bellin
- Department of Civil, Environmental and Mechanical Engineering, University of Trento, Trento, Italy.,Agriculture, Food and Environment Centre (C3A), University of Trento, San Michele all'Adige, Italy
| | - Elena Turco
- Sustainable Agro-Ecosystems and Bioresources Department, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Giulia Molinatto
- Department of Agricultural, Forest and Food Sciences, University of Turin, Turin, Italy
| | - Damiano Gianelle
- Sustainable Agro-Ecosystems and Bioresources Department, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
| | - Ilaria Pertot
- Sustainable Agro-Ecosystems and Bioresources Department, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy.,Agriculture, Food and Environment Centre (C3A), University of Trento, San Michele all'Adige, Italy
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31
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Koop-Jakobsen K, Mueller P, Meier RJ, Liebsch G, Jensen K. Plant-Sediment Interactions in Salt Marshes - An Optode Imaging Study of O 2, pH, and CO 2 Gradients in the Rhizosphere. FRONTIERS IN PLANT SCIENCE 2018; 9:541. [PMID: 29774037 PMCID: PMC5943611 DOI: 10.3389/fpls.2018.00541] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 04/06/2018] [Indexed: 05/26/2023]
Abstract
In many wetland plants, belowground transport of O2 via aerenchyma tissue and subsequent O2 loss across root surfaces generates small oxic root zones at depth in the rhizosphere with important consequences for carbon and nutrient cycling. This study demonstrates how roots of the intertidal salt-marsh plant Spartina anglica affect not only O2, but also pH and CO2 dynamics, resulting in distinct gradients of O2, pH, and CO2 in the rhizosphere. A novel planar optode system (VisiSens TD®, PreSens GmbH) was used for taking high-resolution 2D-images of the O2, pH, and CO2 distribution around roots during alternating light-dark cycles. Belowground sediment oxygenation was detected in the immediate vicinity of the roots, resulting in oxic root zones with a 1.7 mm radius from the root surface. CO2 accumulated around the roots, reaching a concentration up to threefold higher than the background concentration, and generally affected a larger area within a radius of 12.6 mm from the root surface. This contributed to a lowering of pH by 0.6 units around the roots. The O2, pH, and CO2 distribution was recorded on the same individual roots over diurnal light cycles in order to investigate the interlinkage between sediment oxygenation and CO2 and pH patterns. In the rhizosphere, oxic root zones showed higher oxygen concentrations during illumination of the aboveground biomass. In darkness, intraspecific differences were observed, where some plants maintained oxic root zones in darkness, while others did not. However, the temporal variation in sediment oxygenation was not reflected in the temporal variations of pH and CO2 around the roots, which were unaffected by changing light conditions at all times. This demonstrates that plant-mediated sediment oxygenation fueling microbial decomposition and chemical oxidation has limited impact on the dynamics of pH and CO2 in S. anglica rhizospheres, which may in turn be controlled by other processes such as root respiration and root exudation.
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Affiliation(s)
- Ketil Koop-Jakobsen
- MARUM – Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany
| | - Peter Mueller
- Applied Plant Ecology, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
| | | | | | - Kai Jensen
- Applied Plant Ecology, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
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Lenzewski N, Mueller P, Meier RJ, Liebsch G, Jensen K, Koop-Jakobsen K. Dynamics of oxygen and carbon dioxide in rhizospheres of Lobelia dortmanna - a planar optode study of belowground gas exchange between plants and sediment. THE NEW PHYTOLOGIST 2018; 218:131-141. [PMID: 29314005 DOI: 10.1111/nph.14973] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 11/21/2017] [Indexed: 05/24/2023]
Abstract
Root-mediated CO2 uptake, O2 release and their effects on O2 and CO2 dynamics in the rhizosphere of Lobelia dortmanna were investigated. Novel planar optode technology, imaging CO2 and O2 distribution around single roots, provided insights into the spatiotemporal patterns of gas exchange between roots, sediment and microbial community. In light, O2 release and CO2 uptake were pronounced, resulting in a distinct oxygenated zone (radius: c. 3 mm) and a CO2 -depleted zone (radius: c. 2 mm) around roots. Simultaneously, however, microbial CO2 production was stimulated within a larger zone around the roots (radius: c. 10 mm). This gave rise to a distinct pattern with a CO2 minimum at the root surface and a CO2 maximum c. 2 mm away from the root. In darkness, CO2 uptake ceased, and the CO2 -depleted zone disappeared within 2 h. By contrast, the oxygenated root zone remained even after 8 h, but diminished markedly over time. A tight coupling between photosynthetic processes and the spatiotemporal dynamics of O2 and CO2 in the rhizosphere of Lobelia was demonstrated, and we suggest that O2 -induced stimulation of the microbial community in the sediment increases the supply of inorganic carbon for photosynthesis by building up a CO2 reservoir in the rhizosphere.
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Affiliation(s)
- Nikola Lenzewski
- Applied Plant Ecology, Biocenter Klein Flottbek, Universität Hamburg, Ohnhorststrasse 18, 22609, Hamburg, Germany
| | - Peter Mueller
- Applied Plant Ecology, Biocenter Klein Flottbek, Universität Hamburg, Ohnhorststrasse 18, 22609, Hamburg, Germany
| | | | - Gregor Liebsch
- PreSens, Precision Sensing GmbH, Am BioPark 11, 93053, Regensburg, Germany
| | - Kai Jensen
- Applied Plant Ecology, Biocenter Klein Flottbek, Universität Hamburg, Ohnhorststrasse 18, 22609, Hamburg, Germany
| | - Ketil Koop-Jakobsen
- MARUM - Center for Marine Environmental Sciences, University of Bremen, Leobener Strasse 8, 28359, Bremen, Germany
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Sakpirom J, Kantachote D, Nunkaew T, Khan E. Characterizations of purple non-sulfur bacteria isolated from paddy fields, and identification of strains with potential for plant growth-promotion, greenhouse gas mitigation and heavy metal bioremediation. Res Microbiol 2017; 168:266-275. [DOI: 10.1016/j.resmic.2016.12.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 12/14/2016] [Accepted: 12/15/2016] [Indexed: 10/20/2022]
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Han C, Ren J, Tang H, Xu D, Xie X. Quantitative imaging of radial oxygen loss from Valisneria spiralis roots with a fluorescent planar optode. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 569-570:1232-1240. [PMID: 27387799 DOI: 10.1016/j.scitotenv.2016.06.198] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 06/25/2016] [Accepted: 06/25/2016] [Indexed: 06/06/2023]
Abstract
Oxygen (O2) availability within the sediment-root interface is critical to the survival of macrophytes in O2-deficient sediment; however, our knowledge of the fine-scale impact of macrophyte roots upon the spatiotemporal dynamics of O2 is relatively limited. In this study, a non-invasive imaging technology was utilized to map O2 micro-distribution around Vallisneria spiralis. Long-term imaging results gathered during a 36day-period revealed an abundance of O2 spatiotemporal patterns ranging from 0 to 250μmolL(-1). The root-induced O2 leakage and consequent oxygenated area were stronger in the vicinity of the basal root compared to that found in the root tip. The O2 images revealed V. spiralis exhibited radial O2 loss (ROL) along the entire root, and the O2 distribution along the root length showed a high degree of small-scale spatial heterogeneity decreasing from 80% at the basal root surface to 10% at the root tip. The oxygenated zone area around the roots increased as O2 levels increased with root growth and irradiance intensities ranging from 0 to 216μmol photons m(-2)s(-1). A weak ROL measuring <20% air saturation around the basal root surface was maintained in darkness, which was presumably attributed to the O2 supply from overlying water via plant aerenchyma. The estimated total O2 release to the rhizosphere of V. spiralis was determined to range from 8.80±7.32 to 30.34±17.71nmolm(-2)s(-1), which is much higher than many other macrophyte species. This O2 release may be an important contribution to the high-capacity of V. spiralis for quickly colonizing anaerobic sediment.
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Affiliation(s)
- Chao Han
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Jinghua Ren
- Geological Survey of Jiangsu Province, Nanjing 210018, China
| | - Hao Tang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Di Xu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
| | - Xianchuan Xie
- State Key Laboratory of Pollution Control and Resource Reuse, Center for Hydroscience Research, School of the Environment, Nanjing University, Nanjing 210093, China.
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Musilova L, Ridl J, Polivkova M, Macek T, Uhlik O. Effects of Secondary Plant Metabolites on Microbial Populations: Changes in Community Structure and Metabolic Activity in Contaminated Environments. Int J Mol Sci 2016; 17:E1205. [PMID: 27483244 PMCID: PMC5000603 DOI: 10.3390/ijms17081205] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 06/20/2016] [Accepted: 07/15/2016] [Indexed: 12/19/2022] Open
Abstract
Secondary plant metabolites (SPMEs) play an important role in plant survival in the environment and serve to establish ecological relationships between plants and other organisms. Communication between plants and microorganisms via SPMEs contained in root exudates or derived from litter decomposition is an example of this phenomenon. In this review, the general aspects of rhizodeposition together with the significance of terpenes and phenolic compounds are discussed in detail. We focus specifically on the effect of SPMEs on microbial community structure and metabolic activity in environments contaminated by polychlorinated biphenyls (PCBs) and polyaromatic hydrocarbons (PAHs). Furthermore, a section is devoted to a complex effect of plants and/or their metabolites contained in litter on bioremediation of contaminated sites. New insights are introduced from a study evaluating the effects of SPMEs derived during decomposition of grapefruit peel, lemon peel, and pears on bacterial communities and their ability to degrade PCBs in a long-term contaminated soil. The presented review supports the "secondary compound hypothesis" and demonstrates the potential of SPMEs for increasing the effectiveness of bioremediation processes.
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Affiliation(s)
- Lucie Musilova
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Technicka 3, 166 28 Prague, Czech Republic.
| | - Jakub Ridl
- Department of Genomics and Bioinformatics, Institute of Molecular Genetics of the Czech Academy of Sciences, Videnska 1083, 142 20 Prague, Czech Republic.
| | - Marketa Polivkova
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Technicka 3, 166 28 Prague, Czech Republic.
| | - Tomas Macek
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Technicka 3, 166 28 Prague, Czech Republic.
| | - Ondrej Uhlik
- Department of Biochemistry and Microbiology, Faculty of Food and Biochemical Technology, University of Chemistry and Technology Prague, Technicka 3, 166 28 Prague, Czech Republic.
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Li G, Kronzucker HJ, Shi W. The Response of the Root Apex in Plant Adaptation to Iron Heterogeneity in Soil. FRONTIERS IN PLANT SCIENCE 2016; 7:344. [PMID: 27047521 PMCID: PMC4800179 DOI: 10.3389/fpls.2016.00344] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 03/07/2016] [Indexed: 05/30/2023]
Abstract
Iron (Fe) is an essential micronutrient for plant growth and development, and is frequently limiting. By contrast, over-accumulation of Fe in plant tissues leads to toxicity. In soils, the distribution of Fe is highly heterogeneous. To cope with this heterogeneity, plant roots engage an array of adaptive responses to adjust their morphology and physiology. In this article, we review root morphological and physiological changes in response to low- and high-Fe conditions and highlight differences between these responses. We especially focus on the role of the root apex in dealing with the stresses resulting from Fe shortage and excess.
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Affiliation(s)
- Guangjie Li
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of SciencesNanjing, China
| | | | - Weiming Shi
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of SciencesNanjing, China
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Oburger E, Schmidt H. New Methods To Unravel Rhizosphere Processes. TRENDS IN PLANT SCIENCE 2016; 21:243-255. [PMID: 26776474 DOI: 10.1016/j.tplants.2015.12.005] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Revised: 12/01/2015] [Accepted: 12/09/2015] [Indexed: 05/19/2023]
Abstract
Root-triggered processes (growth, uptake and release of solutes) vary in space and time, and interact with heterogeneous soil microenvironments that provide habitats for (micro)biota on various scales. Despite tremendous progress in method development in the past decades, finding a suitable experimental set-up to investigate processes occurring at the dynamic conjunction of biosphere, hydrosphere, and pedosphere in the close vicinity of active plant roots still represents a major challenge. We discuss recent methodological developments in rhizosphere research with a focus on imaging techniques. We further review established concepts that have been updated with novel techniques, highlighting the need for combinatorial approaches to disentangle rhizosphere processes on relevant scales.
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Affiliation(s)
- Eva Oburger
- University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences, Institute of Soil Research, Konrad-Lorenz Strasse 24, 3430 Tulln, Austria.
| | - Hannes Schmidt
- University of Vienna, Research Network 'Chemistry meets Microbiology', Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, Althanstrasse 14, 1090 Vienna, Austria.
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Santner J, Larsen M, Kreuzeder A, Glud RN. Two decades of chemical imaging of solutes in sediments and soils--a review. Anal Chim Acta 2015; 878:9-42. [PMID: 26002324 DOI: 10.1016/j.aca.2015.02.006] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 02/03/2015] [Accepted: 02/05/2015] [Indexed: 01/08/2023]
Abstract
The increasing appreciation of the small-scale (sub-mm) heterogeneity of biogeochemical processes in sediments, wetlands and soils has led to the development of several methods for high-resolution two-dimensional imaging of solute distribution in porewaters. Over the past decades, localised sampling of solutes (diffusive equilibration in thin films, diffusive gradients in thin films) followed by planar luminescent sensors (planar optodes) have been used as analytical tools for studies on solute distribution and dynamics. These approaches have provided new conceptual and quantitative understanding of biogeochemical processes regulating the distribution of key elements and solutes including O2, CO2, pH, redox conditions as well as nutrient and contaminant ion species in structurally complex soils and sediments. Recently these methods have been applied in parallel or integrated as so-called sandwich sensors for multianalyte measurements. Here we review the capabilities and limitations of the chemical imaging methods that are currently at hand, using a number of case studies, and provide an outlook on potential future developments for two-dimensional solute imaging in soils and sediments.
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Affiliation(s)
- Jakob Santner
- Rhizosphere Ecology and Biogeochemistry Group, Department of Forest and Soil Sciences, Institute of Soil Research, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz-Strasse 24, 3430 Tulln, Austria.
| | - Morten Larsen
- Nordic Center for Earth Evolution (NordCEE), University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark
| | - Andreas Kreuzeder
- Rhizosphere Ecology and Biogeochemistry Group, Department of Forest and Soil Sciences, Institute of Soil Research, University of Natural Resources and Life Sciences Vienna, Konrad Lorenz-Strasse 24, 3430 Tulln, Austria
| | - Ronnie N Glud
- Nordic Center for Earth Evolution (NordCEE), University of Southern Denmark, Campusvej 55, 5230 Odense, Denmark; Scottish Marine Institute, Scottish Association for Marine Science, Oban, Scotland, PA37 1QA, UK; Greenland Climate Research Centre (CO Greenland Institute of Natural Resources), Kivioq 2, Box 570, 3900 Nuuk, Greenland; Arctic Research Centre, Aarhus University, 8000 Aarhus, Denmark
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