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Rolando JL, Kolton M, Song T, Liu Y, Pinamang P, Conrad R, Morris JT, Konstantinidis KT, Kostka JE. Sulfur oxidation and reduction are coupled to nitrogen fixation in the roots of the salt marsh foundation plant Spartina alterniflora. Nat Commun 2024; 15:3607. [PMID: 38684658 PMCID: PMC11059160 DOI: 10.1038/s41467-024-47646-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 04/09/2024] [Indexed: 05/02/2024] Open
Abstract
Heterotrophic activity, primarily driven by sulfate-reducing prokaryotes, has traditionally been linked to nitrogen fixation in the root zone of coastal marine plants, leaving the role of chemolithoautotrophy in this process unexplored. Here, we show that sulfur oxidation coupled to nitrogen fixation is a previously overlooked process providing nitrogen to coastal marine macrophytes. In this study, we recovered 239 metagenome-assembled genomes from a salt marsh dominated by the foundation plant Spartina alterniflora, including diazotrophic sulfate-reducing and sulfur-oxidizing bacteria. Abundant sulfur-oxidizing bacteria encode and highly express genes for carbon fixation (RuBisCO), nitrogen fixation (nifHDK) and sulfur oxidation (oxidative-dsrAB), especially in roots stressed by sulfidic and reduced sediment conditions. Stressed roots exhibited the highest rates of nitrogen fixation and expression level of sulfur oxidation and sulfate reduction genes. Close relatives of marine symbionts from the Candidatus Thiodiazotropha genus contributed ~30% and ~20% of all sulfur-oxidizing dsrA and nitrogen-fixing nifK transcripts in stressed roots, respectively. Based on these findings, we propose that the symbiosis between S. alterniflora and sulfur-oxidizing bacteria is key to ecosystem functioning of coastal salt marshes.
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Affiliation(s)
- J L Rolando
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
| | - M Kolton
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
- French Associates Institute for Agriculture and Biotechnology of Drylands, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - T Song
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
| | - Y Liu
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
- The Pennsylvania State University, Department of Civil & Environmental Engineering, University Park, PA, 16802, USA
| | - P Pinamang
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
| | - R Conrad
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
| | - J T Morris
- Belle Baruch Institute for Marine & Coastal Sciences, University of South Carolina, Columbia, SC, 29201, USA
| | - K T Konstantinidis
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
- Georgia Institute of Technology, School of Civil and Environmental Engineering, Atlanta, GA, 30332, USA
| | - J E Kostka
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA.
- Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA, 30332, USA.
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
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Song T, Liu Y, Kolton M, Wilson RM, Keller JK, Rolando JL, Chanton JP, Kostka JE. Porewater constituents inhibit microbially mediated greenhouse gas production (GHG) and regulate the response of soil organic matter decomposition to warming in anoxic peat from a Sphagnum-dominated bog. FEMS Microbiol Ecol 2023; 99:fiad060. [PMID: 37280172 DOI: 10.1093/femsec/fiad060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 05/16/2023] [Accepted: 06/05/2023] [Indexed: 06/08/2023] Open
Abstract
Northern peatlands store approximately one-third of terrestrial soil carbon. Climate warming is expected to stimulate the microbially mediated degradation of peat soil organic matter (SOM), leading to increasing greenhouse gas (GHG; carbon dioxide, CO2; methane, CH4) production and emission. Porewater dissolved organic matter (DOM) plays a key role in SOM decomposition; however, the mechanisms controlling SOM decomposition and its response to warming remain unclear. The temperature dependence of GHG production and microbial community dynamics were investigated in anoxic peat from a Sphagnum-dominated peatland. In this study, peat decomposition, which was quantified by GHG production and carbon substrate utilization is limited by terminal electron acceptors (TEA) and DOM, and these controls of microbially mediated SOM degradation are temperature-dependent. Elevated temperature led to a slight decrease in microbial diversity, and stimulated the growth of specific methanotrophic and syntrophic taxa. These results confirm that DOM is a major driver of decomposition in peatland soils contains inhibitory compounds, but the inhibitory effect is alleviated by warming.
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Affiliation(s)
- Tianze Song
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States
| | - Yutong Liu
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States
- Department of Civil & Environmental Engineering, Pennsylvania State University, University Park, University Park, PA 16802, United States
| | - Max Kolton
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States
- French Associates Institute for Agriculture and Biotechnology of Drylands, Ben-Gurion, University of the Negev, Beer Sheva, 8499000, Israel
| | - Rachel M Wilson
- Department of Earth, Ocean & Atmospheric Science, Florida State University, Tallahassee, FL 32304, United States
| | - Jason K Keller
- Schmid College of Science and Technology, Chapman University, 1 University Dr, Orange, CA 92866, United States
| | - Jose L Rolando
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States
| | - Jeffrey P Chanton
- Department of Earth, Ocean & Atmospheric Science, Florida State University, Tallahassee, FL 32304, United States
| | - Joel E Kostka
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, United States
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30318, United States
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30332, United States
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Rolando JL, Kolton M, Song T, Kostka JE. The core root microbiome of Spartina alterniflora is predominated by sulfur-oxidizing and sulfate-reducing bacteria in Georgia salt marshes, USA. Microbiome 2022; 10:37. [PMID: 35227326 PMCID: PMC8886783 DOI: 10.1186/s40168-021-01187-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/25/2021] [Indexed: 05/12/2023]
Abstract
BACKGROUND Salt marshes are dominated by the smooth cordgrass Spartina alterniflora on the US Atlantic and Gulf of Mexico coastlines. Although soil microorganisms are well known to mediate important biogeochemical cycles in salt marshes, little is known about the role of root microbiomes in supporting the health and productivity of marsh plant hosts. Leveraging in situ gradients in aboveground plant biomass as a natural laboratory, we investigated the relationships between S. alterniflora primary productivity, sediment redox potential, and the physiological ecology of bulk sediment, rhizosphere, and root microbial communities at two Georgia barrier islands over two growing seasons. RESULTS A marked decrease in prokaryotic alpha diversity with high abundance and increased phylogenetic dispersion was found in the S. alterniflora root microbiome. Significantly higher rates of enzymatic organic matter decomposition, as well as the relative abundances of putative sulfur (S)-oxidizing, sulfate-reducing, and nitrifying prokaryotes correlated with plant productivity. Moreover, these functional guilds were overrepresented in the S. alterniflora rhizosphere and root core microbiomes. Core microbiome bacteria from the Candidatus Thiodiazotropha genus, with the metabolic potential to couple S oxidation with C and N fixation, were shown to be highly abundant in the root and rhizosphere of S. alterniflora. CONCLUSIONS The S. alterniflora root microbiome is dominated by highly active and competitive species taking advantage of available carbon substrates in the oxidized root zone. Two microbially mediated mechanisms are proposed to stimulate S. alterniflora primary productivity: (i) enhanced microbial activity replenishes nutrients and terminal electron acceptors in higher biomass stands, and (ii) coupling of chemolithotrophic S oxidation with carbon (C) and nitrogen (N) fixation by root- and rhizosphere-associated prokaryotes detoxifies sulfide in the root zone while potentially transferring fixed C and N to the host plant. Video Abstract.
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Affiliation(s)
- Jose L Rolando
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
| | - Max Kolton
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
- French Associates Institute for Agriculture and Biotechnology of Drylands, Ben-Gurion, University of the Negev, Beer Sheva, Israel
| | - Tianze Song
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA
| | - Joel E Kostka
- Georgia Institute of Technology, School of Biological Sciences, Atlanta, GA, 30332, USA.
- Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA, 30332, USA.
- Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
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Ramírez DA, Rolando JL, Yactayo W, Monneveux P, Mares V, Quiroz R. Improving potato drought tolerance through the induction of long-term water stress memory. Plant Sci 2015; 238:26-32. [PMID: 26259171 DOI: 10.1016/j.plantsci.2015.05.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/17/2015] [Accepted: 05/21/2015] [Indexed: 05/22/2023]
Abstract
Knowledge of drought tolerance in potato is limited and very little is known about stress memory in this crop. In the present study, long-term stress memory was tested on tuber yield and drought tolerance related traits in three potato varieties (Unica, Désirée and Sarnav) with contrasted yields under water restriction. Seed tubers produced by plants grown under non-restricted (non-primed tubers) and restricted (primed tubers) water conditions were sown and exposed to similar watering treatments. Tuber yield and leaf greenness of plants from primed and non-primed seeds as well as tuber carbon isotope discrimination (Δ(13)C) and antioxidant activity (AA) responses to watering treatments were compared. Higher tuber yield, both under non-restricted and restricted water regimes, was produced by primed Sarnav plants. The decrease of tuber yield and Δ(13)C with water restriction was lower in primed Unica plants. Long-term stress memory consequently appears to be highly genotype-dependent in potato. Its expression in plants originated from primed tubers and facing water restriction seems to be positively associated to the degree of inherent capability of the cultivar to yield under water restriction. However, other effects of priming appear to be genotype-independent as priming enhanced the tuber AA in response to water restriction in the three varieties.
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Affiliation(s)
- D A Ramírez
- International Potato Center (CIP), Apartado 1558, Lima 12, Peru; Water Resources PhD Program, Universidad Nacional Agraria La Molina, Av. La Molina s/n, Lima, Peru.
| | - J L Rolando
- International Potato Center (CIP), Apartado 1558, Lima 12, Peru
| | - W Yactayo
- International Potato Center (CIP), Apartado 1558, Lima 12, Peru
| | - P Monneveux
- International Potato Center (CIP), Apartado 1558, Lima 12, Peru
| | - V Mares
- International Potato Center (CIP), Apartado 1558, Lima 12, Peru
| | - R Quiroz
- International Potato Center (CIP), Apartado 1558, Lima 12, Peru
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