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Ren J, Cui Z, Wang Y, Ning Q, Gao Y. Transcriptomic insights into the potential impacts of flavonoids and nodule-specific cysteine-rich peptides on nitrogen fixation in Vicia villosa and Vicia sativa. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 214:108936. [PMID: 39018775 DOI: 10.1016/j.plaphy.2024.108936] [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: 06/16/2024] [Accepted: 07/12/2024] [Indexed: 07/19/2024]
Abstract
Vicia villosa (VV) and Vicia sativa (VS) are legume forages highly valued for their excellent nitrogen fixation. However, no research has addressed the mechanisms underlying their differences in nitrogen fixation. This study employed physiological, cytological, and comparative transcriptomic approaches to elucidate the disparities in nitrogen fixation between them. Our results showed that the total amount of nitrogen fixed was 60.45% greater in VV than in VS, and the comprehensive nitrogen response performance was 94.19% greater, while the nitrogen fixation efficiency was the same. The infection zone and differentiated bacteroid proportion in mature VV root nodules were 33.76% and 19.35% greater, respectively, than those in VS. The size of the VV genome was 15.16% larger than that of the VS genome, consistent with its greater biomass. A significant enrichment of the flavonoid biosynthetic pathway was found only for VV-specific genes, among which chalcone-flavonone isomerase, caffeoyl-CoA-O-methyltransferase and stilbene synthase were extremely highly expressed. The VV-specific genes also exhibited significant enrichment in symbiotic nodulation; genes related to nodule-specific cysteine-rich peptides (NCRs) comprised 61.11% of the highly expressed genes. qRT‒PCR demonstrated that greater enrichment and expression of the dominant NCR (Unigene0004451) were associated with greater nodule bacteroid differentiation and greater nitrogen fixation in VV. Our findings suggest that the greater total nitrogen fixation of VV was attributed to its larger biomass, leading to a greater nitrogen demand and enhanced fixation physiology. This process is likely achieved by the synergistic effects of high bacteroid differentiation along with high expression of flavonoid and NCR genes.
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Affiliation(s)
- Jian Ren
- Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Institute of Grassland Science, Northeast Normal University, Changchun, 130024, China; Xinjiang Agricultural University, Key Laboratory of Grassland Resources and Ecology of Western Arid Desert Area of the Ministry of Education, College of Grassland Science, Urumqi, 830052, China
| | - Zhengguo Cui
- Soybean Research Institute, Jilin Academy of Agricultural Sciences/National Engineering Research Center for Soybean, Changchun, 130033, China
| | - Yueqiang Wang
- Soybean Research Institute, Jilin Academy of Agricultural Sciences/National Engineering Research Center for Soybean, Changchun, 130033, China
| | - Qiushi Ning
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yingzhi Gao
- Key Laboratory of Vegetation Ecology of the Ministry of Education, Jilin Songnen Grassland Ecosystem National Observation and Research Station, State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, Institute of Grassland Science, Northeast Normal University, Changchun, 130024, China; Xinjiang Agricultural University, Key Laboratory of Grassland Resources and Ecology of Western Arid Desert Area of the Ministry of Education, College of Grassland Science, Urumqi, 830052, China.
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2
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Zhang X, Wu J, Kong Z. Cellular basis of legume-rhizobium symbiosis. PLANT COMMUNICATIONS 2024:101045. [PMID: 39099171 DOI: 10.1016/j.xplc.2024.101045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 07/30/2024] [Accepted: 07/31/2024] [Indexed: 08/06/2024]
Abstract
The legume-rhizobium symbiosis represents the most important system for terrestrial biological nitrogen fixation on land. Efficient nitrogen fixation during this symbiosis depends on successful rhizobial infection and complete endosymbiosis, which are achieved by complex cellular events including cell-wall remodeling, cytoskeletal reorganizations, and extensive membrane expansion and trafficking. In this review, we explore the dynamic remodeling of the plant-specific cell wall-membrane system-cytoskeleton (WMC) continuum during symbiotic nitrogen fixation. We focus on key processes linked to efficient nitrogen fixation, including rhizobial uptake, infection thread formation and elongation, rhizobial droplet release, cytoplasmic bridge formation, and rhizobial endosymbiosis. Additionally, we discuss the advanced techniques for investigating the cellular basis of root-nodule symbiosis and provide insights into the unsolved mysteries of robust symbiotic nitrogen fixation.
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Affiliation(s)
- Xiaxia Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jingxia Wu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhaosheng Kong
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; Houji Laboratory in Shanxi Province, Academy of Agronomy, Shanxi, China.
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3
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Ghosh P, Chakraborty J. Exploring the role of symbiotic modifier peptidases in the legume - rhizobium symbiosis. Arch Microbiol 2024; 206:147. [PMID: 38462552 DOI: 10.1007/s00203-024-03920-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 03/12/2024]
Abstract
Legumes can establish a mutual association with soil-derived nitrogen-fixing bacteria called 'rhizobia' forming lateral root organs called root nodules. Rhizobia inside the root nodules get transformed into 'bacteroids' that can fix atmospheric nitrogen to ammonia for host plants in return for nutrients and shelter. A substantial 200 million tons of nitrogen is fixed annually through biological nitrogen fixation. Consequently, the symbiotic mechanism of nitrogen fixation is utilized worldwide for sustainable agriculture and plays a crucial role in the Earth's ecosystem. The development of effective nitrogen-fixing symbiosis between legumes and rhizobia is very specialized and requires coordinated signaling. A plethora of plant-derived nodule-specific cysteine-rich (NCR or NCR-like) peptides get actively involved in this complex and tightly regulated signaling process of symbiosis between some legumes of the IRLC (Inverted Repeat-Lacking Clade) and Dalbergioid clades and nitrogen-fixing rhizobia. Recent progress has been made in identifying two such peptidases that actively prevent bacterial differentiation, leading to symbiotic incompatibility. In this review, we outlined the functions of NCRs and two nitrogen-fixing blocking peptidases: HrrP (host range restriction peptidase) and SapA (symbiosis-associated peptidase A). SapA was identified through an overexpression screen from the Sinorhizobium meliloti 1021 core genome, whereas HrrP is inherited extra-chromosomally. Interestingly, both peptidases affect the symbiotic outcome by degrading the NCR peptides generated from the host plants. These NCR-degrading peptidases can shed light on symbiotic incompatibility, helping to elucidate the reasons behind the inefficiency of nitrogen fixation observed in certain groups of rhizobia with specific legumes.
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Affiliation(s)
- Prithwi Ghosh
- Department of Botany, Narajole Raj College, Vidyasagar University, Midnapore, 721211, India.
| | - Joydeep Chakraborty
- School of Plant Sciences and Food Security, Tel Aviv University, Tel-Aviv, Israel
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4
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Ayala-García P, Jiménez-Guerrero I, Müsken M, Ollero FJ, Borrero-De Acuña JM, Pérez-Montaño F. Isolation of Rhizobial Extracellular Membrane Vesicles from Bacteroids. Methods Mol Biol 2024; 2751:229-236. [PMID: 38265720 DOI: 10.1007/978-1-0716-3617-6_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
Extracellular-membrane vesicles (EMVs) are spherical buds of the extracellular membrane, commonly produced by Gram-negative bacteria, known to mediate intricate inter-kingdom communication. In this context, comprehensive research dissecting the role of EMVs in one of the most complex nature-occurring molecular dialogues, rhizobium-legume symbiosis, has been so far neglected. During the different stages of the symbiotic process, rhizobia and their host plants establish a very specific and controlled intercellular trafficking of signal molecules. Thus, as conveyors of a broad range of molecules into the target cell, EMVs are gaining weight in the field. Here, we describe a detailed protocol to isolate EMVs from bacteroids of legume nodules, opening a new door for discovering new authors of the symbiotic process.
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Affiliation(s)
| | | | - Mathias Müsken
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
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5
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Alleman AB, Peters JW. Mechanisms for Generating Low Potential Electrons across the Metabolic Diversity of Nitrogen-Fixing Bacteria. Appl Environ Microbiol 2023; 89:e0037823. [PMID: 37154716 PMCID: PMC10231201 DOI: 10.1128/aem.00378-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023] Open
Abstract
The availability of fixed nitrogen is a limiting factor in the net primary production of all ecosystems. Diazotrophs overcome this limit through the conversion of atmospheric dinitrogen to ammonia. Diazotrophs are phylogenetically diverse bacteria and archaea that exhibit a wide range of lifestyles and metabolisms, including obligate anaerobes and aerobes that generate energy through heterotrophic or autotrophic metabolisms. Despite the diversity of metabolisms, all diazotrophs use the same enzyme, nitrogenase, to reduce N2. Nitrogenase is an O2-sensitive enzyme that requires a high amount of energy in the form of ATP and low potential electrons carried by ferredoxin (Fd) or flavodoxin (Fld). This review summarizes how the diverse metabolisms of diazotrophs utilize different enzymes to generate low potential reducing equivalents for nitrogenase catalysis. These enzymes include substrate-level Fd oxidoreductases, hydrogenases, photosystem I or other light-driven reaction centers, electron bifurcating Fix complexes, proton motive force-driven Rnf complexes, and Fd:NAD(P)H oxidoreductases. Each of these enzymes is critical for generating low potential electrons while simultaneously integrating the native metabolism to balance nitrogenase's overall energy needs. Understanding the diversity of electron transport systems to nitrogenase in various diazotrophs will be essential to guide future engineering strategies aimed at expanding the contributions of biological nitrogen fixation in agriculture.
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Affiliation(s)
- Alexander B. Alleman
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, USA
| | - John W. Peters
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, Oklahoma, USA
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Paries M, Gutjahr C. The good, the bad, and the phosphate: regulation of beneficial and detrimental plant-microbe interactions by the plant phosphate status. THE NEW PHYTOLOGIST 2023. [PMID: 37145847 DOI: 10.1111/nph.18933] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 03/21/2023] [Indexed: 05/06/2023]
Abstract
Phosphate (Pi ) is indispensable for life on this planet. However, for sessile land plants it is poorly accessible. Therefore, plants have developed a variety of strategies for enhanced acquisition and recycling of Pi . The mechanisms to cope with Pi limitation as well as direct uptake of Pi from the substrate via the root epidermis are regulated by a conserved Pi starvation response (PSR) system based on a family of key transcription factors (TFs) and their inhibitors. Furthermore, plants obtain Pi indirectly through symbiosis with mycorrhiza fungi, which employ their extensive hyphal network to drastically increase the soil volume that can be explored by plants for Pi . Besides mycorrhizal symbiosis, there is also a variety of other interactions with epiphytic, endophytic, and rhizospheric microbes that can indirectly or directly influence plant Pi uptake. It was recently discovered that the PSR pathway is involved in the regulation of genes that promote formation and maintenance of AM symbiosis. Furthermore, the PSR system influences plant immunity and can also be a target of microbial manipulation. It is known for decades that the nutritional status of plants influences the outcome of plant-microbe interactions. The first molecular explanations for these observations are now emerging.
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Affiliation(s)
- Michael Paries
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, Freising, 85354, Germany
| | - Caroline Gutjahr
- Plant Genetics, TUM School of Life Sciences, Technical University of Munich (TUM), Emil Ramann Str. 4, Freising, 85354, Germany
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
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7
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Han K, Li Y, Zhang Z, Sun L, Wang ET, Li Y. Comparative genome analysis of Sesbania cannabina-nodulating Rhizobium spp. revealing the symbiotic and transferrable characteristics of symbiosis plasmids. Microb Genom 2023; 9. [PMID: 37133904 DOI: 10.1099/mgen.0.001004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023] Open
Abstract
Symbiotic nitrogen fixation between legumes and rhizobia makes a great contribution to the terrestrial ecosystem. The successful symbiosis between the partners mainly depends on the nod and nif genes in rhizobia, while the specific symbiosis is mainly determined by the structure of Nod factors and the corresponding secretion systems (type III secretion system; T3SS), etc. These symbiosis genes are usually located on symbiotic plasmids or a chromosomal symbiotic island, both could be transferred interspecies. In our previous studies, Sesbania cannabina-nodulating rhizobia across the world were classified into 16 species of four genera and all the strains, especially those of Rhizobium spp., harboured extraordinarily highly conserved symbiosis genes, suggesting that horizontal transfer of symbiosis genes might have happened among them. In order to learn the genomic basis of diversification of rhizobia under the selection of host specificity, we performed this study to compare the complete genome sequences of four Rhizobium strains associated with S. cannabina, YTUBH007, YTUZZ027, YTUHZ044 and YTUHZ045. Their complete genomes were sequenced and assembled at the replicon level. Each strain represents a different species according to the average nucleotide identity (ANI) values calculated using the whole-genome sequences; furthermore, except for YTUBH007, which was classified as Rhizobium binae, the remaining three strains were identified as new candidate species. A single symbiotic plasmid sized 345-402 kb containing complete nod, nif, fix, T3SS and conjugal transfer genes was detected in each strain. The high ANI and amino acid identity (AAI) values, as well as the close phylogenetic relationships among the entire symbiotic plasmid sequences, indicate that they have the same origin and the entire plasmid has been transferred among different Rhizobium species. These results indicate that S. cannabina stringently selects a certain symbiosis gene background of the rhizobia for nodulation, which might have forced the symbiosis genes to transfer from some introduced rhizobia to the related native or local-condition-adapted bacteria. The existence of almost complete conjugal transfer related elements, but not the gene virD, indicated that the self-transfer of the symbiotic plasmid in these rhizobial strains may be realized via a virD-independent pathway or through another unidentified gene. This study provides insight for the better understanding of high-frequency symbiotic plasmid transfer, host-specific nodulation and the host shift for rhizobia.
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Affiliation(s)
- Kunming Han
- Yantai Key Laboratory of Characteristic Agricultural Bioresource Conservation & Germplasm Innovative Utilization, College of Life Sciences, Yantai University, Yantai, Shandong 264005, PR China
| | - Yan Li
- Yantai Key Laboratory of Characteristic Agricultural Bioresource Conservation & Germplasm Innovative Utilization, College of Life Sciences, Yantai University, Yantai, Shandong 264005, PR China
| | - Zhenpeng Zhang
- Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, PR China
| | - Liqin Sun
- Yantai Key Laboratory of Characteristic Agricultural Bioresource Conservation & Germplasm Innovative Utilization, College of Life Sciences, Yantai University, Yantai, Shandong 264005, PR China
| | - En Tao Wang
- Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Mexico City 11340, Mexico
| | - Yan Li
- Yantai Key Laboratory of Characteristic Agricultural Bioresource Conservation & Germplasm Innovative Utilization, College of Life Sciences, Yantai University, Yantai, Shandong 264005, PR China
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8
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Mazoyon C, Hirel B, Pecourt A, Catterou M, Gutierrez L, Sarazin V, Dubois F, Duclercq J. Sphingomonas sediminicola Is an Endosymbiotic Bacterium Able to Induce the Formation of Root Nodules in Pea ( Pisum sativum L.) and to Enhance Plant Biomass Production. Microorganisms 2023; 11:microorganisms11010199. [PMID: 36677491 PMCID: PMC9861922 DOI: 10.3390/microorganisms11010199] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/13/2023] Open
Abstract
The application of bacterial bio-inputs is a very attractive alternative to the use of mineral fertilisers. In ploughed soils including a crop rotation pea, we observed an enrichment of bacterial communities with Sphingomonas (S.) sediminicola. Inoculation experiments, cytological studies, and de novo sequencing were used to investigate the beneficial role of S. sediminicola in pea. S. sediminicola is able to colonise pea plants and establish a symbiotic association that promotes plant biomass production. Sequencing of the S. sediminicola genome revealed the existence of genes involved in secretion systems, Nod factor synthesis, and nitrogenase activity. Light and electron microscopic observations allowed us to refine the different steps involved in the establishment of the symbiotic association, including the formation of infection threads, the entry of the bacteria into the root cells, and the development of differentiated bacteroids in root nodules. These results, together with phylogenetic analysis, demonstrated that S. sediminicola is a non-rhizobia that has the potential to develop a beneficial symbiotic association with a legume. Such a symbiotic association could be a promising alternative for the development of more sustainable agricultural practices, especially under reduced N fertilisation conditions.
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Affiliation(s)
- Candice Mazoyon
- Unité Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR7058 CNRS), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
| | - Bertrand Hirel
- Unité Mixte de Recherche 1318 INRA-AgroParisTech, Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique et de l'Environnement (INRAE), 78026 Versailles, France
| | - Audrey Pecourt
- Unité Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR7058 CNRS), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
| | - Manuella Catterou
- Unité Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR7058 CNRS), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
| | - Laurent Gutierrez
- Centre de Ressources Régionales en Biologie Moléculaire (CRRBM), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
| | | | - Fréderic Dubois
- Unité Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR7058 CNRS), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
| | - Jérôme Duclercq
- Unité Ecologie et Dynamique des Systèmes Anthropisés (EDYSAN, UMR7058 CNRS), Université de Picardie Jules Verne (UPJV), 80000 Amiens, France
- Correspondence: ; Tel.: +33-3-22827612
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9
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Luo Y, Liu W, Sun J, Zhang ZR, Yang WC. Quantitative proteomics reveals key pathways in the symbiotic interface and the likely extracellular property of soybean symbiosome. J Genet Genomics 2023; 50:7-19. [PMID: 35470091 DOI: 10.1016/j.jgg.2022.04.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 02/06/2023]
Abstract
An effective symbiosis between legumes and rhizobia relies largely on diverse proteins at the plant-rhizobium interface for material transportation and signal transduction during symbiotic nitrogen fixation. Here, we report a comprehensive proteome atlas of the soybean symbiosome membrane (SM), peribacteroid space (PBS), and root microsomal fraction (RMF) using state-of-the-art label-free quantitative proteomic technology. In total, 1759 soybean proteins with diverse functions are detected in the SM, and 1476 soybean proteins and 369 rhizobial proteins are detected in the PBS. The diversity of SM proteins detected suggests multiple origins of the SM. Quantitative comparative analysis highlights amino acid metabolism and nutrient uptake in the SM, indicative of the key pathways in nitrogen assimilation. The detection of soybean secretory proteins in the PBS and receptor-like kinases in the SM provides evidence for the likely extracellular property of the symbiosome and the potential signaling communication between both symbionts at the symbiotic interface. Our proteomic data provide clues for how some of the sophisticated regulation between soybean and rhizobium at the symbiotic interface is achieved, and suggest approaches for symbiosis engineering.
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Affiliation(s)
- Yu Luo
- The State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Wei Liu
- The State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Juan Sun
- The State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zheng-Rong Zhang
- The State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei-Cai Yang
- The State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
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10
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Vlk D, Trněný O, Řepková J. Genes Associated with Biological Nitrogen Fixation Efficiency Identified Using RNA Sequencing in Red Clover ( Trifolium pratense L.). LIFE (BASEL, SWITZERLAND) 2022; 12:life12121975. [PMID: 36556339 PMCID: PMC9785344 DOI: 10.3390/life12121975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/22/2022] [Accepted: 11/22/2022] [Indexed: 11/29/2022]
Abstract
Commonly studied in the context of legume-rhizobia symbiosis, biological nitrogen fixation (BNF) is a key component of the nitrogen cycle in nature. Despite its potential in plant breeding and many years of research, information is still lacking as to the regulation of hundreds of genes connected with plant-bacteria interaction, nodulation, and nitrogen fixation. Here, we compared root nodule transcriptomes of red clover (Trifolium pratense L.) genotypes with contrasting nitrogen fixation efficiency, and we found 491 differentially expressed genes (DEGs) between plants with high and low BNF efficiency. The annotation of genes expressed in nodules revealed more than 800 genes not yet experimentally confirmed. Among genes mediating nodule development, four nod-ule-specific cysteine-rich (NCR) peptides were confirmed in the nodule transcriptome. Gene duplication analyses revealed that genes originating from tandem and dispersed duplication are significantly over-represented among DEGs. Weighted correlation network analysis (WGCNA) organized expression profiles of the transcripts into 16 modules linked to the analyzed traits, such as nitrogen fixation efficiency or sample-specific modules. Overall, the results obtained broaden our knowledge about transcriptomic landscapes of red clover's root nodules and shift the phenotypic description of BNF efficiency on the level of gene expression in situ.
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Affiliation(s)
- David Vlk
- Department of Experimental Biology, Faculty of Sciences, Masaryk University, 611 37 Brno, Czech Republic
| | - Oldřich Trněný
- Agricultural Research, Ltd., Zahradní 1, 664 41 Troubsko, Czech Republic
| | - Jana Řepková
- Department of Experimental Biology, Faculty of Sciences, Masaryk University, 611 37 Brno, Czech Republic
- Correspondence: ; Tel.: +420-549-49-6895
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11
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Dinkins RD, Hancock JA, Bickhart DM, Sullivan ML, Zhu H. Expression and Variation of the Genes Involved in Rhizobium Nodulation in Red Clover. PLANTS (BASEL, SWITZERLAND) 2022; 11:2888. [PMID: 36365339 PMCID: PMC9655500 DOI: 10.3390/plants11212888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/21/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
Red clover (Trifolium pratense L.) is an important forage crop and serves as a major contributor of nitrogen input in pasture settings because of its ability to fix atmospheric nitrogen. During the legume-rhizobial symbiosis, the host plant undergoes a large number of gene expression changes, leading to development of root nodules that house the rhizobium bacteria as they are converted into nitrogen-fixing bacteroids. Many of the genes involved in symbiosis are conserved across legume species, while others are species-specific with little or no homology across species and likely regulate the specific plant genotype/symbiont strain interactions. Red clover has not been widely used for studying symbiotic nitrogen fixation, primarily due to its outcrossing nature, making genetic analysis rather complicated. With the addition of recent annotated genomic resources and use of RNA-seq tools, we annotated and characterized a number of genes that are expressed only in nodule forming roots. These genes include those encoding nodule-specific cysteine rich peptides (NCRs) and nodule-specific Polycystin-1, Lipoxygenase, Alpha toxic (PLAT) domain proteins (NPDs). Our results show that red clover encodes one of the highest number of NCRs and ATS3-like/NPDs, which are postulated to increase nitrogen fixation efficiency, in the Inverted-Repeat Lacking Clade (IRLC) of legumes. Knowledge of the variation and expression of these genes in red clover will provide more insights into the function of these genes in regulating legume-rhizobial symbiosis and aid in breeding of red clover genotypes with increased nitrogen fixation efficiency.
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Affiliation(s)
- Randy D. Dinkins
- Forage-Animal Production Research Unit, USDA-ARS, Lexington, KY 40506, USA
| | - Julie A. Hancock
- College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40508, USA
| | | | | | - Hongyan Zhu
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA
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12
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Zorin EA, Kliukova MS, Afonin AM, Gribchenko ES, Gordon ML, Sulima AS, Zhernakov AI, Kulaeva OA, Romanyuk DA, Kusakin PG, Tsyganova AV, Tsyganov VE, Tikhonovich IA, Zhukov VA. A variable gene family encoding nodule-specific cysteine-rich peptides in pea ( Pisum sativum L.). FRONTIERS IN PLANT SCIENCE 2022; 13:884726. [PMID: 36186063 PMCID: PMC9515463 DOI: 10.3389/fpls.2022.884726] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Accepted: 08/08/2022] [Indexed: 06/16/2023]
Abstract
Various legume plants form root nodules in which symbiotic bacteria (rhizobia) fix atmospheric nitrogen after differentiation into a symbiotic form named bacteroids. In some legume species, bacteroid differentiation is promoted by defensin-like nodule-specific cysteine-rich (NCR) peptides. NCR peptides have best been studied in the model legume Medicago truncatula Gaertn., while in many other legumes relevant information is still fragmentary. Here, we characterize the NCR gene family in pea (Pisum sativum L.) using genomic and transcriptomic data. We found 360 genes encoding NCR peptides that are expressed in nodules. The sequences of pea NCR genes and putative peptides are highly variable and differ significantly from NCR sequences of M. truncatula. Indeed, only one pair of orthologs (PsNCR47-MtNCR312) has been identified. The NCR genes in the pea genome are located in clusters, and the expression patterns of NCR genes from one cluster tend to be similar. These data support the idea of independent evolution of NCR genes by duplication and diversification in related legume species. We also described spatiotemporal expression profiles of NCRs and identified specific transcription factor (TF) binding sites in promoters of "early" and "late" NCR genes. Further, we studied the expression of NCR genes in nodules of Fix- mutants and predicted potential regulators of NCR gene expression, one among them being the TF ERN1 involved in the early steps of nodule organogenesis. In general, this study contributes to understanding the functions of NCRs in legume nodules and contributes to understanding the diversity and potential antibiotic properties of pea nodule-specific antimicrobial molecules.
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Affiliation(s)
- Evgeny A. Zorin
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | - Marina S. Kliukova
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | - Alexey M. Afonin
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | - Emma S. Gribchenko
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | - Mikhail L. Gordon
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | - Anton S. Sulima
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | | | - Olga A. Kulaeva
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | - Daria A. Romanyuk
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | - Pyotr G. Kusakin
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | - Anna V. Tsyganova
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | - Viktor E. Tsyganov
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
| | - Igor A. Tikhonovich
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
- Department of Genetics and Biotechnology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Vladimir A. Zhukov
- All-Russia Research Institute for Agricultural Microbiology, Saint Petersburg, Russia
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13
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Zhang Y, Gallant É, Park JD, Seyedsayamdost MR. The Small-Molecule Language of Dynamic Microbial Interactions. Annu Rev Microbiol 2022; 76:641-660. [PMID: 35679616 PMCID: PMC10171915 DOI: 10.1146/annurev-micro-042722-091052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although microbes are routinely grown in monocultures in the laboratory, they are almost never encountered as single species in the wild. Our ability to detect and identify new microorganisms has advanced significantly in recent years, but our understanding of the mechanisms that mediate microbial interactions has lagged behind. What makes this task more challenging is that microbial alliances can be dynamic, consisting of multiple phases. The transitions between phases, and the interactions in general, are often mediated by a chemical language consisting of small molecules, also referred to as secondary metabolites or natural products. In this microbial lexicon, the molecules are like words and through their effects on recipient cells they convey meaning. The current review highlights three dynamic microbial interactions in which some of the words and their meanings have been characterized, especially those that mediate transitions in selected multiphasic associations. These systems provide insights into the principles that govern microbial symbioses and a playbook for interrogating similar associations in diverse ecological niches. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Yifan Zhang
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA; ,
| | - Étienne Gallant
- Department of Chemistry, Princeton University, Princeton, New Jersey, USA; ,
| | - Jong-Duk Park
- Department of Chemistry, Princeton University, Princeton, New Jersey, USA; ,
| | - Mohammad R Seyedsayamdost
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA; , .,Department of Chemistry, Princeton University, Princeton, New Jersey, USA; ,
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14
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Eardly B, Meor Osman WA, Ardley J, Zandberg J, Gollagher M, van Berkum P, Elia P, Marinova D, Seshadri R, Reddy TBK, Ivanova N, Pati A, Woyke T, Kyrpides N, Loedolff M, Laird DW, Reeve W. The Genome of the Acid Soil-Adapted Strain Rhizobium favelukesii OR191 Encodes Determinants for Effective Symbiotic Interaction With Both an Inverted Repeat Lacking Clade and a Phaseoloid Legume Host. Front Microbiol 2022; 13:735911. [PMID: 35495676 PMCID: PMC9048898 DOI: 10.3389/fmicb.2022.735911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Accepted: 02/10/2022] [Indexed: 11/15/2022] Open
Abstract
Although Medicago sativa forms highly effective symbioses with the comparatively acid-sensitive genus Ensifer, its introduction into acid soils appears to have selected for symbiotic interactions with acid-tolerant R. favelukesii strains. Rhizobium favelukesii has the unusual ability of being able to nodulate and fix nitrogen, albeit sub-optimally, not only with M. sativa but also with the promiscuous host Phaseolus vulgaris. Here we describe the genome of R. favelukesii OR191 and genomic features important for the symbiotic interaction with both of these hosts. The OR191 draft genome contained acid adaptation loci, including the highly acid-inducible lpiA/acvB operon and olsC, required for production of lysine- and ornithine-containing membrane lipids, respectively. The olsC gene was also present in other acid-tolerant Rhizobium strains but absent from the more acid-sensitive Ensifer microsymbionts. The OR191 symbiotic genes were in general more closely related to those found in Medicago microsymbionts. OR191 contained the nodA, nodEF, nodHPQ, and nodL genes for synthesis of polyunsaturated, sulfated and acetylated Nod factors that are important for symbiosis with Medicago, but contained a truncated nodG, which may decrease nodulation efficiency with M. sativa. OR191 contained an E. meliloti type BacA, which has been shown to specifically protect Ensifer microsymbionts from Medicago nodule-specific cysteine-rich peptides. The nitrogen fixation genes nifQWZS were present in OR191 and P. vulgaris microsymbionts but absent from E. meliloti-Medicago microsymbionts. The ability of OR191 to nodulate and fix nitrogen symbiotically with P. vulgaris indicates that this host has less stringent requirements for nodulation than M. sativa but may need rhizobial strains that possess nifQWZS for N2-fixation to occur. OR191 possessed the exo genes required for the biosynthesis of succinoglycan, which is required for the Ensifer-Medicago symbiosis. However, 1H-NMR spectra revealed that, in the conditions tested, OR191 exopolysaccharide did not contain a succinyl substituent but instead contained a 3-hydroxybutyrate moiety, which may affect its symbiotic performance with Medicago hosts. These findings provide a foundation for the genetic basis of nodulation requirements and symbiotic effectiveness with different hosts.
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Affiliation(s)
- Bertrand Eardly
- Berks College, Penn State University, Reading, PA, United States
| | - Wan Adnawani Meor Osman
- Centre for Crop and Food Innovation, College of Science, Health, Engineering and Education, Food Futures Institute, Murdoch University, Murdoch, WA, Australia
| | - Julie Ardley
- Centre for Crop and Food Innovation, College of Science, Health, Engineering and Education, Food Futures Institute, Murdoch University, Murdoch, WA, Australia
| | - Jaco Zandberg
- Centre for Crop and Food Innovation, College of Science, Health, Engineering and Education, Food Futures Institute, Murdoch University, Murdoch, WA, Australia
| | - Margaret Gollagher
- Murdoch University Associate, Murdoch, WA, Australia.,Sustainability and Biosecurity, Department of Primary Industries and Regional Development, South Perth, WA, Australia
| | - Peter van Berkum
- Soybean Genomics and Improvement Laboratory, United States Department of Agriculture, Beltsville, MD, United States
| | - Patrick Elia
- Soybean Genomics and Improvement Laboratory, United States Department of Agriculture, Beltsville, MD, United States
| | - Dora Marinova
- Curtin University Sustainability Policy Institute, Curtin University, Bentley, WA, Australia
| | - Rekha Seshadri
- Department of Energy (DOE) Joint Genome Institute, Berkeley, CA, United States
| | - T B K Reddy
- Department of Energy (DOE) Joint Genome Institute, Berkeley, CA, United States
| | - Natalia Ivanova
- Department of Energy (DOE) Joint Genome Institute, Berkeley, CA, United States
| | - Amrita Pati
- Department of Energy (DOE) Joint Genome Institute, Berkeley, CA, United States
| | - Tanja Woyke
- Department of Energy (DOE) Joint Genome Institute, Berkeley, CA, United States
| | - Nikos Kyrpides
- Department of Energy (DOE) Joint Genome Institute, Berkeley, CA, United States
| | - Matthys Loedolff
- Centre for Crop and Food Innovation, College of Science, Health, Engineering and Education, Food Futures Institute, Murdoch University, Murdoch, WA, Australia
| | - Damian W Laird
- Centre for Water Energy and Waste, Harry Butler Institute, Murdoch University, Murdoch, WA, Australia
| | - Wayne Reeve
- Centre for Crop and Food Innovation, College of Science, Health, Engineering and Education, Food Futures Institute, Murdoch University, Murdoch, WA, Australia
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15
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Cangioli L, Vaccaro F, Fini M, Mengoni A, Fagorzi C. Scent of a Symbiont: The Personalized Genetic Relationships of Rhizobium-Plant Interaction. Int J Mol Sci 2022; 23:3358. [PMID: 35328782 PMCID: PMC8954435 DOI: 10.3390/ijms23063358] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 01/24/2023] Open
Abstract
Many molecular signals are exchanged between rhizobia and host legume plants, some of which are crucial for symbiosis to take place, while others are modifiers of the interaction, which have great importance in the competition with the soil microbiota and in the genotype-specific perception of host plants. Here, we review recent findings on strain-specific and host genotype-specific interactions between rhizobia and legumes, discussing the molecular actors (genes, gene products and metabolites) which play a role in the establishment of symbiosis, and highlighting the need for research including the other components of the soil (micro)biota, which could be crucial in developing rational-based strategies for bioinoculants and synthetic communities' assemblage.
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Affiliation(s)
- Lisa Cangioli
- Department of Biology, University of Florence, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
| | - Francesca Vaccaro
- Department of Biology, University of Florence, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
| | - Margherita Fini
- Department of Biology, University of Florence, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
| | - Alessio Mengoni
- Department of Biology, University of Florence, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
| | - Camilla Fagorzi
- Department of Biology, University of Florence, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
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16
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Chen W, Chi Y, Zhang J, Bai B, Ji X, Shen Y. MtWRP1, a Novel Fabacean Specific Gene, Regulates Root Nodulation and Plant Growth in Medicago truncatula. Genes (Basel) 2022; 13:genes13020193. [PMID: 35205237 PMCID: PMC8871812 DOI: 10.3390/genes13020193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 01/16/2022] [Accepted: 01/19/2022] [Indexed: 02/04/2023] Open
Abstract
Fabaceans symbiotically interact with nitrogen-fixing rhizobacteria to form root nodules. Some fabacean specific proteins play important roles in the symbiosis. WRKY-related Protein (WRP) is a novel fabacean specific protein, whose functions have not been well characterized. In this study, MtWRP1 was functionally characterized in Medicago truncatula. It contains a WRKY domain at C-terminal and a novel transmembrane (TM) domain at N-terminal, and its WRKY domain was highly similar to the N-terminal WRKY domain of the group I WRKY proteins. The TM domain was highly homologous to the eukaryotic cytochrome b561 (Cytb561) proteins from birds. Subcellular localization revealed that MtWRP1 was targeted to the Golgi apparatus through the novel TM domain. MtWRP1 was highly expressed in roots and nodules, suggesting its possible roles in the regulation of root growth and nodulation. Both MtWRP1-overexpression transgenic M. truncatula and MtWRP1 mutants showed altered root nodulation and plant growth performance. Specifically, the formation of root nodules was significantly reduced in the absence of MtWRP1. These results demonstrated that MtWRP1 plays critical roles in root nodulation and plant growth.
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17
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Yurgel SN, Qu Y, Rice JT, Ajeethan N, Zink EM, Brown JM, Purvine S, Lipton MS, Kahn ML. Specialization in a Nitrogen-Fixing Symbiosis: Proteome Differences Between Sinorhizobium medicae Bacteria and Bacteroids. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:1409-1422. [PMID: 34402628 DOI: 10.1094/mpmi-07-21-0180-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Using tandem mass spectrometry (MS/MS), we analyzed the proteome of Sinorhizobium medicae WSM419 growing as free-living cells and in symbiosis with Medicago truncatula. In all, 3,215 proteins were identified, over half of the open reading frames predicted from the genomic sequence. The abundance of 1,361 proteins displayed strong lifestyle bias. In total, 1,131 proteins had similar levels in bacteroids and free-living cells, and the low levels of 723 proteins prevented statistically significant assignments. Nitrogenase subunits comprised approximately 12% of quantified bacteroid proteins. Other major bacteroid proteins included symbiosis-specific cytochromes and FixABCX, which transfer electrons to nitrogenase. Bacteroids had normal levels of proteins involved in amino acid biosynthesis, glycolysis or gluconeogenesis, and the pentose phosphate pathway; however, several amino acid degradation pathways were repressed. This suggests that bacteroids maintain a relatively independent anabolic metabolism. Tricarboxylic acid cycle proteins were highly expressed in bacteroids and no other catabolic pathway emerged as an obvious candidate to supply energy and reductant to nitrogen fixation. Bacterial stress response proteins were induced in bacteroids. Many WSM419 proteins that are not encoded in S. meliloti Rm1021 were detected, and understanding the functions of these proteins might clarify why S. medicae WSM419 forms a more effective symbiosis with M. truncatula than S. meliloti Rm1021.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Svetlana N Yurgel
- Department of Plant, Food and Environmental Sciences, Faculty of Agriculture, Dalhousie University, P.O. Box 550, Truro, Nova Scotia, B2N 5E3, Canada
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, U.S.A
| | - Yi Qu
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, U.S.A
| | - Jennifer T Rice
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, U.S.A
| | - Nivethika Ajeethan
- Department of Plant, Food and Environmental Sciences, Faculty of Agriculture, Dalhousie University, P.O. Box 550, Truro, Nova Scotia, B2N 5E3, Canada
- Faculty of Technology, University of Jaffna, Sri Lanka
| | - Erika M Zink
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, U.S.A
| | - Joseph M Brown
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, U.S.A
| | - Sam Purvine
- Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, U.S.A
| | - Mary S Lipton
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, U.S.A
| | - Michael L Kahn
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, U.S.A
- School of Molecular Biosciences, Washington State University, Pullman, WA 99164-6340, U.S.A
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18
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Identification of a Novel Pyruvyltransferase Using 13C Solid-State Nuclear Magnetic Resonance To Analyze Rhizobial Exopolysaccharides. J Bacteriol 2021; 203:e0040321. [PMID: 34606371 DOI: 10.1128/jb.00403-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The alphaproteobacterium Sinorhizobium meliloti secretes two acidic exopolysaccharides (EPSs), succinoglycan (EPSI) and galactoglucan (EPSII), which differentially enable it to adapt to a changing environment. Succinoglycan is essential for invasion of plant hosts and, thus, for the formation of nitrogen-fixing root nodules. Galactoglucan is critical for population-based behaviors such as swarming and biofilm formation and can facilitate invasion in the absence of succinoglycan on some host plants. The biosynthesis of galactoglucan is not as completely understood as that of succinoglycan. We devised a pipeline to identify putative pyruvyltransferase and acetyltransferase genes, construct genomic deletions in strains engineered to produce either succinoglycan or galactoglucan, and analyze EPS from mutant bacterial strains. EPS samples were examined by 13C cross-polarization magic-angle spinning (CPMAS) solid-state nuclear magnetic resonance (NMR). CPMAS NMR is uniquely suited to defining chemical composition in complex samples and enables the detection and quantification of distinct EPS functional groups. Galactoglucan was isolated from mutant strains with deletions in five candidate acyl/acetyltransferase genes (exoZ, exoH, SMb20810, SMb21188, and SMa1016) and a putative pyruvyltransferase (wgaE or SMb21322). Most samples were similar in composition to wild-type EPSII by CPMAS NMR analysis. However, galactoglucan produced from a strain lacking wgaE exhibited a significant reduction in pyruvylation. Pyruvylation was restored through the ectopic expression of plasmid-borne wgaE. Our work has thus identified WgaE as a galactoglucan pyruvyltransferase. This exemplifies how the systematic combination of genetic analyses and solid-state NMR detection is a rapid means to identify genes responsible for modification of rhizobial exopolysaccharides. IMPORTANCE Nitrogen-fixing bacteria are crucial for geochemical cycles and global nitrogen nutrition. Symbioses between legumes and rhizobial bacteria establish root nodules, where bacteria convert dinitrogen to ammonia for plant utilization. Secreted exopolysaccharides (EPSs) produced by Sinorhizobium meliloti (succinoglycan and galactoglucan) play important roles in soil and plant environments. The biosynthesis of galactoglucan is not as well characterized as that of succinoglycan. We employed solid-state nuclear magnetic resonance (NMR) to examine intact EPS from wild-type and mutant S. meliloti strains. NMR analysis of EPS isolated from a wgaE gene mutant revealed a novel pyruvyltransferase that modifies galactoglucan. Few EPS pyruvyltransferases have been characterized. Our work provides insight into the biosynthesis of an important S. meliloti EPS and expands the knowledge of enzymes that modify polysaccharides.
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19
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Maire J, Blackall LL, van Oppen MJH. Intracellular Bacterial Symbionts in Corals: Challenges and Future Directions. Microorganisms 2021; 9:2209. [PMID: 34835335 PMCID: PMC8619543 DOI: 10.3390/microorganisms9112209] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/21/2021] [Accepted: 10/21/2021] [Indexed: 02/07/2023] Open
Abstract
Corals are the main primary producers of coral reefs and build the three-dimensional reef structure that provides habitat to more than 25% of all marine eukaryotes. They harbor a complex consortium of microorganisms, including bacteria, archaea, fungi, viruses, and protists, which they rely on for their survival. The symbiosis between corals and bacteria is poorly studied, and their symbiotic relationships with intracellular bacteria are only just beginning to be acknowledged. In this review, we emphasize the importance of characterizing intracellular bacteria associated with corals and explore how successful approaches used to study such microorganisms in other systems could be adapted for research on corals. We propose a framework for the description, identification, and functional characterization of coral-associated intracellular bacterial symbionts. Finally, we highlight the possible value of intracellular bacteria in microbiome manipulation and mitigating coral bleaching.
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Affiliation(s)
- Justin Maire
- School of Biosciences, The University of Melbourne, Melbourne, VIC 3010, Australia; (L.L.B.); (M.J.H.v.O.)
| | - Linda L. Blackall
- School of Biosciences, The University of Melbourne, Melbourne, VIC 3010, Australia; (L.L.B.); (M.J.H.v.O.)
| | - Madeleine J. H. van Oppen
- School of Biosciences, The University of Melbourne, Melbourne, VIC 3010, Australia; (L.L.B.); (M.J.H.v.O.)
- Australian Institute of Marine Science, Townsville, QLD 4810, Australia
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20
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Bellabarba A, Bacci G, Decorosi F, Aun E, Azzarello E, Remm M, Giovannetti L, Viti C, Mengoni A, Pini F. Competitiveness for Nodule Colonization in Sinorhizobium meliloti: Combined In Vitro-Tagged Strain Competition and Genome-Wide Association Analysis. mSystems 2021. [PMID: 34313466 DOI: 10.1101/2020.09.15.298034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023] Open
Abstract
Associations between leguminous plants and symbiotic nitrogen-fixing rhizobia are a classic example of mutualism between a eukaryotic host and a specific group of prokaryotic microbes. Although this symbiosis is in part species specific, different rhizobial strains may colonize the same nodule. Some rhizobial strains are commonly known as better competitors than others, but detailed analyses that aim to predict rhizobial competitive abilities based on genomes are still scarce. Here, we performed a bacterial genome-wide association (GWAS) analysis to define the genomic determinants related to the competitive capabilities in the model rhizobial species Sinorhizobium meliloti. For this, 13 tester strains were green fluorescent protein (GFP) tagged and assayed versus 3 red fluorescent protein (RFP)-tagged reference competitor strains (Rm1021, AK83, and BL225C) in a Medicago sativa nodule occupancy test. Competition data and strain genomic sequences were employed to build a model for GWAS based on k-mers. Among the k-mers with the highest scores, 51 k-mers mapped on the genomes of four strains showing the highest competition phenotypes (>60% single strain nodule occupancy; GR4, KH35c, KH46, and SM11) versus BL225C. These k-mers were mainly located on the symbiosis-related megaplasmid pSymA, specifically on genes coding for transporters, proteins involved in the biosynthesis of cofactors, and proteins related to metabolism (e.g., fatty acids). The same analysis was performed considering the sum of single and mixed nodules obtained in the competition assays versus BL225C, retrieving k-mers mapped on the genes previously found and on vir genes. Therefore, the competition abilities seem to be linked to multiple genetic determinants and comprise several cellular components. IMPORTANCE Decoding the competitive pattern that occurs in the rhizosphere is challenging in the study of bacterial social interaction strategies. To date, the single-gene approach has mainly been used to uncover the bases of nodulation, but there is still a knowledge gap regarding the main features that a priori characterize rhizobial strains able to outcompete indigenous rhizobia. Therefore, tracking down which traits make different rhizobial strains able to win the competition for plant infection over other indigenous rhizobia will improve the strain selection process and, consequently, plant yield in sustainable agricultural production systems. We proved that a k-mer-based GWAS approach can efficiently identify the competition determinants of a panel of strains previously analyzed for their plant tissue occupancy using double fluorescent labeling. The reported strategy will be useful for detailed studies on the genomic aspects of the evolution of bacterial symbiosis and for an extensive evaluation of rhizobial inoculants.
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Affiliation(s)
- Agnese Bellabarba
- Department of Agronomy, Food, Environmental and Forestry (DAGRI), University of Florencegrid.8404.8, Sesto Fiorentino, Italy
- Genexpress Laboratory, Department of Agronomy, Food, Environmental and Forestry (DAGRI), University of Florencegrid.8404.8, Sesto Fiorentino, Italy
| | - Giovanni Bacci
- Department of Biology, University of Florencegrid.8404.8, Sesto Fiorentino, Italy
| | - Francesca Decorosi
- Department of Agronomy, Food, Environmental and Forestry (DAGRI), University of Florencegrid.8404.8, Sesto Fiorentino, Italy
- Genexpress Laboratory, Department of Agronomy, Food, Environmental and Forestry (DAGRI), University of Florencegrid.8404.8, Sesto Fiorentino, Italy
| | - Erki Aun
- Department of Bioinformatics, Institute of Molecular and Cell Biology, University of Tartugrid.10939.32, Tartu, Estonia
| | - Elisa Azzarello
- Department of Agronomy, Food, Environmental and Forestry (DAGRI), University of Florencegrid.8404.8, Sesto Fiorentino, Italy
| | - Maido Remm
- Department of Bioinformatics, Institute of Molecular and Cell Biology, University of Tartugrid.10939.32, Tartu, Estonia
| | - Luciana Giovannetti
- Department of Agronomy, Food, Environmental and Forestry (DAGRI), University of Florencegrid.8404.8, Sesto Fiorentino, Italy
- Genexpress Laboratory, Department of Agronomy, Food, Environmental and Forestry (DAGRI), University of Florencegrid.8404.8, Sesto Fiorentino, Italy
| | - Carlo Viti
- Department of Agronomy, Food, Environmental and Forestry (DAGRI), University of Florencegrid.8404.8, Sesto Fiorentino, Italy
- Genexpress Laboratory, Department of Agronomy, Food, Environmental and Forestry (DAGRI), University of Florencegrid.8404.8, Sesto Fiorentino, Italy
| | - Alessio Mengoni
- Department of Biology, University of Florencegrid.8404.8, Sesto Fiorentino, Italy
| | - Francesco Pini
- Department of Biology, University of Bari Aldo Morogrid.7644.1, Bari, Italy
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21
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Competitiveness for Nodule Colonization in Sinorhizobium meliloti: Combined In Vitro-Tagged Strain Competition and Genome-Wide Association Analysis. mSystems 2021; 6:e0055021. [PMID: 34313466 PMCID: PMC8407117 DOI: 10.1128/msystems.00550-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Associations between leguminous plants and symbiotic nitrogen-fixing rhizobia are a classic example of mutualism between a eukaryotic host and a specific group of prokaryotic microbes. Although this symbiosis is in part species specific, different rhizobial strains may colonize the same nodule. Some rhizobial strains are commonly known as better competitors than others, but detailed analyses that aim to predict rhizobial competitive abilities based on genomes are still scarce. Here, we performed a bacterial genome-wide association (GWAS) analysis to define the genomic determinants related to the competitive capabilities in the model rhizobial species Sinorhizobium meliloti. For this, 13 tester strains were green fluorescent protein (GFP) tagged and assayed versus 3 red fluorescent protein (RFP)-tagged reference competitor strains (Rm1021, AK83, and BL225C) in a Medicago sativa nodule occupancy test. Competition data and strain genomic sequences were employed to build a model for GWAS based on k-mers. Among the k-mers with the highest scores, 51 k-mers mapped on the genomes of four strains showing the highest competition phenotypes (>60% single strain nodule occupancy; GR4, KH35c, KH46, and SM11) versus BL225C. These k-mers were mainly located on the symbiosis-related megaplasmid pSymA, specifically on genes coding for transporters, proteins involved in the biosynthesis of cofactors, and proteins related to metabolism (e.g., fatty acids). The same analysis was performed considering the sum of single and mixed nodules obtained in the competition assays versus BL225C, retrieving k-mers mapped on the genes previously found and on vir genes. Therefore, the competition abilities seem to be linked to multiple genetic determinants and comprise several cellular components. IMPORTANCE Decoding the competitive pattern that occurs in the rhizosphere is challenging in the study of bacterial social interaction strategies. To date, the single-gene approach has mainly been used to uncover the bases of nodulation, but there is still a knowledge gap regarding the main features that a priori characterize rhizobial strains able to outcompete indigenous rhizobia. Therefore, tracking down which traits make different rhizobial strains able to win the competition for plant infection over other indigenous rhizobia will improve the strain selection process and, consequently, plant yield in sustainable agricultural production systems. We proved that a k-mer-based GWAS approach can efficiently identify the competition determinants of a panel of strains previously analyzed for their plant tissue occupancy using double fluorescent labeling. The reported strategy will be useful for detailed studies on the genomic aspects of the evolution of bacterial symbiosis and for an extensive evaluation of rhizobial inoculants.
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Antunes VDC, Freitag D, Serrato RV. Differential exopolysaccharide production and composition by Herbaspirillum strains from diverse ecological environments. Arch Microbiol 2021; 203:3883-3892. [PMID: 34009446 DOI: 10.1007/s00203-021-02371-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/22/2021] [Accepted: 05/08/2021] [Indexed: 11/26/2022]
Abstract
Bacteria belonging to the genus Herbaspirillum are found in many different ecological niches. Some species are typically endophytic, while others were reported as free-living organisms that occupy various environments. Also, opportunistic herbaspirilli have been found infecting humans affected by several diseases. We have analyzed the production of exopolysaccharides (EPS) by Herbaspirillum strains isolated from different sources and with distinct ecological characteristics. The monosaccharide composition was determined for the EPS obtained for selected strains including free-living, plant-associated and clinical isolates, and the relationship with the ecological niches occupied by Herbaspirillum spp. is proposed.
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Affiliation(s)
- Valquíria D C Antunes
- Department of Biochemistry and Molecular Biology, Setor de Ciências Biológicas-Centro Politécnico, Universidade Federal do Paraná , R. Francisco H. dos Santos, 100 , PO Box 19046, Curitiba, PR, 81531-980, Brazil
| | - Daniela Freitag
- Department of Biochemistry and Molecular Biology, Setor de Ciências Biológicas-Centro Politécnico, Universidade Federal do Paraná , R. Francisco H. dos Santos, 100 , PO Box 19046, Curitiba, PR, 81531-980, Brazil
| | - Rodrigo V Serrato
- Department of Biochemistry and Molecular Biology, Setor de Ciências Biológicas-Centro Politécnico, Universidade Federal do Paraná , R. Francisco H. dos Santos, 100 , PO Box 19046, Curitiba, PR, 81531-980, Brazil.
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Liu F, Yi M, Liu X, Shen Y, Li J, Wang H, Yang D, Sun Z. Symbiotic Performances of Three Mesorhizobium huakuii Strains Inoculated to Chinese Milk Vetch Varieties. FRONTIERS IN PLANT SCIENCE 2020; 11:599400. [PMID: 33391311 PMCID: PMC7773693 DOI: 10.3389/fpls.2020.599400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 11/20/2020] [Indexed: 06/12/2023]
Abstract
In this experiment, 4 varieties of Chinese milk vetch (Xinyang, Minzi No. 6, Minzi 8487711, and Shishou) were used as host plants and inoculated with 3 strains of rhizobium (CCBAU 2609, M. h 93, and 7653R). The differences in their morphology, yield, and nodule characteristics at different growth stages were studied and the reasons for these differences were analyzed to explore the exclusivity between different varieties of Chinese milk vetch and strains of rhizobium. Results showed no significant difference in plant height and whole-plant dry weight at seedling stage under different treatments but significant differences in these characteristics at full flowering stage. The results indicated that Minzi 8487711 and Shishou were significantly better than the other varieties. During the whole growth period, the growth indexes and nodule characteristics of the 4 varieties inoculated with strain 7653R were better than those of the varieties inoculated with other strains. At full flowering stage, compared with that of the control group, the biomasses of Xinyang, Minzi No.6, Minzi 8487711, and Shishou had increased by 2.04, 2.84, 1.56, and 2.69-fold, respectively, and nitrogenase activities increased by 3.82, 9.60, 6.21, and 15.18%, respectively. Significant differences in the exclusivity between varieties and strains were observed. Minzi No.6-7653R and Shishou variety-7653R had the strongest exclusivity. The results showed that 7653R was a broad-spectrum and high-efficiency rhizobium strain. 7653R is recommended to be used in combination with Chinese milk vetch varieties, such as Minzi 8487711 and Shishou, to obtain advantages in yield and nitrogen fixation in production.
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Affiliation(s)
- Fang Liu
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
- Sheep Industry Development Center of Yulin City, Yulin, China
| | - Mingxuan Yi
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Xinbao Liu
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Yixin Shen
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Jianlong Li
- School of Life Sciences, Nanjing University, Nanjing, China
| | - Hui Wang
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, China
| | - Dianlin Yang
- Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Key Laboratory of Original Agro-Environmental Pollution Prevention and Control, Tianjin Key Laboratory of Agro-Environment and Agro-Product Safety, Tianjin, China
| | - Zhengguo Sun
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
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Compton KK, Hildreth SB, Helm RF, Scharf BE. An Updated Perspective on Sinorhizobium meliloti Chemotaxis to Alfalfa Flavonoids. Front Microbiol 2020; 11:581482. [PMID: 33193213 PMCID: PMC7644916 DOI: 10.3389/fmicb.2020.581482] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/30/2020] [Indexed: 12/25/2022] Open
Abstract
The symbiotic interaction between leguminous plants and their cognate rhizobia allows for the fixation of gaseous dinitrogen into bioavailable ammonia. The perception of host-derived flavonoids is a key initial step for the signaling events that must occur preceding the formation of the nitrogen-fixing organ. Past work investigating chemotaxis – the directed movement of bacteria through chemical gradients – of Bradyrhizobium japonicum, Rhizobium leguminosarum, and Rhizobium meliloti discovered chemotaxis to various organic compounds, but focused on chemotaxis to flavonoids because of their relevance to the symbiosis biochemistry. The current work sought to replicate and further examine Sinorhizobium (Ensifer) meliloti chemotaxis to the flavonoids previously thought to act as the principal attractant molecules prior to the initial signaling stage. Exudate from germinating alfalfa seedlings was analyzed for composition and quantities of different flavonoid compounds using mass spectrometry. The abundance of four prevalent flavonoids in germinating alfalfa seed exudates (SEs) was at a ratio of 200:5:5:1 for hyperoside, luteolin, luteolin-7-glucoside, and chrysoeriol. Using quantitative chemotaxis capillary assays, we did not detect chemotaxis of motile S. meliloti cells to these, and two other flavonoids identified in seed exudates. In support of these findings, the flavonoid fraction of seed exudates was found to be an insignificant attractant relative to the more hydrophilic fraction. Additionally, we observed that cosolvents commonly used to dissolve flavonoids confound the results. We propose that the role flavonoids play in S. meliloti chemotaxis is insignificant relative to other components released by alfalfa seeds.
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Affiliation(s)
- K Karl Compton
- Department of Biological Sciences, Life Sciences I, Virginia Tech, Blacksburg, VA, United States
| | - Sherry B Hildreth
- Department of Biological Sciences, Life Sciences I, Virginia Tech, Blacksburg, VA, United States
| | - Richard F Helm
- Department of Biochemistry, Fralin Life Science Institute, Virginia Tech, Blacksburg, VA, United States
| | - Birgit E Scharf
- Department of Biological Sciences, Life Sciences I, Virginia Tech, Blacksburg, VA, United States
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Fagorzi C, Ilie A, Decorosi F, Cangioli L, Viti C, Mengoni A, diCenzo GC. Symbiotic and Nonsymbiotic Members of the Genus Ensifer (syn. Sinorhizobium) Are Separated into Two Clades Based on Comparative Genomics and High-Throughput Phenotyping. Genome Biol Evol 2020; 12:2521-2534. [PMID: 33283865 PMCID: PMC7719227 DOI: 10.1093/gbe/evaa221] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2020] [Indexed: 01/03/2023] Open
Abstract
Rhizobium–legume symbioses serve as paradigmatic examples for the study of mutualism evolution. The genus Ensifer (syn. Sinorhizobium) contains diverse plant-associated bacteria, a subset of which can fix nitrogen in symbiosis with legumes. To gain insights into the evolution of symbiotic nitrogen fixation (SNF), and interkingdom mutualisms more generally, we performed extensive phenotypic, genomic, and phylogenetic analyses of the genus Ensifer. The data suggest that SNF likely emerged several times within the genus Ensifer through independent horizontal gene transfer events. Yet, the majority (105 of 106) of the Ensifer strains with the nodABC and nifHDK nodulation and nitrogen fixation genes were found within a single, monophyletic clade. Comparative genomics highlighted several differences between the “symbiotic” and “nonsymbiotic” clades, including divergences in their pangenome content. Additionally, strains of the symbiotic clade carried 325 fewer genes, on average, and appeared to have fewer rRNA operons than strains of the nonsymbiotic clade. Initial characterization of a subset of ten Ensifer strains identified several putative phenotypic differences between the clades. Tested strains of the nonsymbiotic clade could catabolize 25% more carbon sources, on average, than strains of the symbiotic clade, and they were better able to grow in LB medium and tolerate alkaline conditions. On the other hand, the tested strains of the symbiotic clade were better able to tolerate heat stress and acidic conditions. We suggest that these data support the division of the genus Ensifer into two main subgroups, as well as the hypothesis that pre-existing genetic features are required to facilitate the evolution of SNF in bacteria.
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Affiliation(s)
- Camilla Fagorzi
- Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - Alexandru Ilie
- Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - Francesca Decorosi
- Genexpress Laboratory, Department of Agriculture, Food, Environment and Forestry, University of Florence, Sesto Fiorentino, Italy
| | - Lisa Cangioli
- Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - Carlo Viti
- Genexpress Laboratory, Department of Agriculture, Food, Environment and Forestry, University of Florence, Sesto Fiorentino, Italy
| | - Alessio Mengoni
- Department of Biology, University of Florence, Sesto Fiorentino, Italy
| | - George C diCenzo
- Department of Biology, University of Florence, Sesto Fiorentino, Italy.,Department of Biology, Queen's University, Kingston, Ontario, Canada
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Abstract
By analyzing successive lifestyle stages of a model Rhizobium-legume symbiosis using mariner-based transposon insertion sequencing (INSeq), we have defined the genes required for rhizosphere growth, root colonization, bacterial infection, N2-fixing bacteroids, and release from legume (pea) nodules. While only 27 genes are annotated as nif and fix in Rhizobium leguminosarum, we show 603 genetic regions (593 genes, 5 transfer RNAs, and 5 RNA features) are required for the competitive ability to nodulate pea and fix N2 Of these, 146 are common to rhizosphere growth through to bacteroids. This large number of genes, defined as rhizosphere-progressive, highlights how critical successful competition in the rhizosphere is to subsequent infection and nodulation. As expected, there is also a large group (211) specific for nodule bacteria and bacteroid function. Nodule infection and bacteroid formation require genes for motility, cell envelope restructuring, nodulation signaling, N2 fixation, and metabolic adaptation. Metabolic adaptation includes urea, erythritol and aldehyde metabolism, glycogen synthesis, dicarboxylate metabolism, and glutamine synthesis (GlnII). There are 17 separate lifestyle adaptations specific to rhizosphere growth and 23 to root colonization, distinct from infection and nodule formation. These results dramatically highlight the importance of competition at multiple stages of a Rhizobium-legume symbiosis.
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Schwember AR, Schulze J, Del Pozo A, Cabeza RA. Regulation of Symbiotic Nitrogen Fixation in Legume Root Nodules. PLANTS (BASEL, SWITZERLAND) 2019; 8:E333. [PMID: 31489914 PMCID: PMC6784058 DOI: 10.3390/plants8090333] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 08/30/2019] [Accepted: 09/04/2019] [Indexed: 12/11/2022]
Abstract
In most legume nodules, the di-nitrogen (N2)-fixing rhizobia are present as organelle-like structures inside their root host cells. Many processes operate and interact within the symbiotic relationship between plants and nodules, including nitrogen (N)/carbon (C) metabolisms, oxygen flow through nodules, oxidative stress, and phosphorous (P) levels. These processes, which influence the regulation of N2 fixation and are finely tuned on a whole-plant basis, are extensively reviewed in this paper. The carbonic anhydrase (CA)-phosphoenolpyruvate carboxylase (PEPC)-malate dehydrogenase (MDH) is a key pathway inside nodules involved in this regulation, and malate seems to play a crucial role in many aspects of symbiotic N2 fixation control. How legumes specifically sense N-status and how this stimulates all of the regulatory factors are key issues for understanding N2 fixation regulation on a whole-plant basis. This must be thoroughly studied in the future since there is no unifying theory that explains all of the aspects involved in regulating N2 fixation rates to date. Finally, high-throughput functional genomics and molecular tools (i.e., miRNAs) are currently very valuable for the identification of many regulatory elements that are good candidates for accurately dissecting the particular N2 fixation control mechanisms associated with physiological responses to abiotic stresses. In combination with existing information, utilizing these abundant genetic molecular tools will enable us to identify the specific mechanisms underlying the regulation of N2 fixation.
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Affiliation(s)
- Andrés R Schwember
- Departamento de Ciencias Vegetales, Facultad de Agronomía e Ingeniería Forestal, Pontificia Universidad Católica de Chile, Santiago 306-22, Chile.
| | - Joachim Schulze
- Department of Crop Science, Section for Plant Nutrition and Crop Physiology, Faculty of Agriculture, University of Goettingen, Carl-Sprengel-Weg 1, 37075 Goettingen, Germany.
| | - Alejandro Del Pozo
- Centro de Mejoramiento Genético y Fenómica Vegetal, Facultad de Ciencias Agrarias, Universidad de Talca, Talca 3460000, Chile.
- Departamento de Producción Agrícola, Facultad de Ciencias Agrarias, Universidad de Talca, Campus Talca, Talca 3460000, Chile.
| | - Ricardo A Cabeza
- Departamento de Producción Agrícola, Facultad de Ciencias Agrarias, Universidad de Talca, Campus Talca, Talca 3460000, Chile.
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Bañuelos-Vazquez LA, Torres Tejerizo G, Cervantes-De La Luz L, Girard L, Romero D, Brom S. Conjugative transfer between Rhizobium etli endosymbionts inside the root nodule. Environ Microbiol 2019; 21:3430-3441. [PMID: 31037804 DOI: 10.1111/1462-2920.14645] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 04/05/2019] [Accepted: 04/26/2019] [Indexed: 11/30/2022]
Abstract
Since the discovery that biological nitrogen fixation ensues in nodules resulting from the interaction of rhizobia with legumes, nodules were thought to be exclusive for hosting nitrogen-fixing and plant growth promoting bacteria. In this work, we uncover a novel function of nodules, as a niche permissive to acquisition of plasmids via conjugative transfer. We used Rhizobium etli CFN42, which nodulates Phaseolus vulgaris. The genome of R. etli CFN42 contains a chromosome and six plasmids. pRet42a is a conjugative plasmid regulated by Quorum-Sensing (QS), and pRet42d is the symbiotic plasmid. Here, using confocal microscopy and flow cytometry, we show that pRet42a transfers on the root's surface, and unexpectedly, inside the nodules. Conjugation still took place inside nodules, even when it was restricted on the plant surface by placing the QS traI regulator under the promoter of the nitrogenase gene, which is only expressed inside the nodules, or by inhibiting the QS transcriptional induction of transfer genes with a traM antiactivator on an unstable vector maintained on the plant surface and lost inside the nodules. These results conclusively confirm the occurrence of conjugation in these structures, defining them as a protected environment for bacterial diversification.
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Affiliation(s)
- Luis Alfredo Bañuelos-Vazquez
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Gonzalo Torres Tejerizo
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Laura Cervantes-De La Luz
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Lourdes Girard
- Programa de Biología de Sistemas y Biología Sintética, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - David Romero
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| | - Susana Brom
- Programa de Ingeniería Genómica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
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Berger A, Boscari A, Frendo P, Brouquisse R. Nitric oxide signaling, metabolism and toxicity in nitrogen-fixing symbiosis. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:4505-4520. [PMID: 30968126 DOI: 10.1093/jxb/erz159] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/28/2019] [Indexed: 05/13/2023]
Abstract
Interactions between legumes and rhizobia lead to the establishment of a symbiotic relationship characterized by the formation of a new organ, the nodule, which facilitates the fixation of atmospheric nitrogen (N2) by nitrogenase through the creation of a hypoxic environment. Significant amounts of nitric oxide (NO) accumulate at different stages of nodule development, suggesting that NO performs specific signaling and/or metabolic functions during symbiosis. NO, which regulates nodule gene expression, accumulates to high levels in hypoxic nodules. NO accumulation is considered to assist energy metabolism within the hypoxic environment of the nodule via a phytoglobin-NO-mediated respiration process. NO is a potent inhibitor of the activity of nitrogenase and other plant and bacterial enzymes, acting as a developmental signal in the induction of nodule senescence. Hence, key questions concern the relative importance of the signaling and metabolic functions of NO versus its toxic action and how NO levels are regulated to be compatible with nitrogen fixation functions. This review analyses these paradoxical roles of NO at various stages of symbiosis, and highlights the role of plant phytoglobins and bacterial hemoproteins in the control of NO accumulation.
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Becerra-Rivera VA, Dunn MF. Polyamine biosynthesis and biological roles in rhizobia. FEMS Microbiol Lett 2019; 366:5476500. [DOI: 10.1093/femsle/fnz084] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 04/22/2019] [Indexed: 12/31/2022] Open
Abstract
ABSTRACTPolyamines are ubiquitous molecules containing two or more amino groups that fulfill varied and often essential physiological and regulatory roles in all organisms. In the symbiotic nitrogen-fixing bacteria known as rhizobia, putrescine and homospermidine are invariably produced while spermidine and norspermidine synthesis appears to be restricted to the alfalfa microsymbiont Sinorhizobium meliloti. Studies with rhizobial mutants deficient in the synthesis of one or more polyamines have shown that these compounds are important for growth, stress resistance, motility, exopolysaccharide production and biofilm formation. In this review, we describe these studies and examine how polyamines are synthesized and regulated in rhizobia.
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Affiliation(s)
- Victor A Becerra-Rivera
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas-Universidad Nacional Autónoma de México, Cuernavaca, Morelos, C.P. 62210, Mexico
| | - Michael F Dunn
- Programa de Genómica Funcional de Procariotes, Centro de Ciencias Genómicas-Universidad Nacional Autónoma de México, Cuernavaca, Morelos, C.P. 62210, Mexico
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31
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diCenzo GC, Zamani M, Checcucci A, Fondi M, Griffitts JS, Finan TM, Mengoni A. Multidisciplinary approaches for studying rhizobium–legume symbioses. Can J Microbiol 2019; 65:1-33. [DOI: 10.1139/cjm-2018-0377] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The rhizobium–legume symbiosis is a major source of fixed nitrogen (ammonia) in the biosphere. The potential for this process to increase agricultural yield while reducing the reliance on nitrogen-based fertilizers has generated interest in understanding and manipulating this process. For decades, rhizobium research has benefited from the use of leading techniques from a very broad set of fields, including population genetics, molecular genetics, genomics, and systems biology. In this review, we summarize many of the research strategies that have been employed in the study of rhizobia and the unique knowledge gained from these diverse tools, with a focus on genome- and systems-level approaches. We then describe ongoing synthetic biology approaches aimed at improving existing symbioses or engineering completely new symbiotic interactions. The review concludes with our perspective of the future directions and challenges of the field, with an emphasis on how the application of a multidisciplinary approach and the development of new methods will be necessary to ensure successful biotechnological manipulation of the symbiosis.
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Affiliation(s)
- George C. diCenzo
- Department of Biology, University of Florence, Sesto Fiorentino, FI 50019, Italy
| | - Maryam Zamani
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Alice Checcucci
- Department of Biology, University of Florence, Sesto Fiorentino, FI 50019, Italy
| | - Marco Fondi
- Department of Biology, University of Florence, Sesto Fiorentino, FI 50019, Italy
| | - Joel S. Griffitts
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602, USA
| | - Turlough M. Finan
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Alessio Mengoni
- Department of Biology, University of Florence, Sesto Fiorentino, FI 50019, Italy
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Revealing the roles of y4wF and tidC genes in Rhizobium tropici CIAT 899: biosynthesis of indolic compounds and impact on symbiotic properties. Arch Microbiol 2018; 201:171-183. [PMID: 30535938 DOI: 10.1007/s00203-018-1607-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Revised: 11/26/2018] [Accepted: 12/03/2018] [Indexed: 01/06/2023]
Abstract
Rhizobium tropici CIAT 899 is a strain known by its ability to nodulate a broad range of legume species, to synthesize a variety of Nod factors, its tolerance of abiotic stresses, and its high capacity to fix atmospheric N2, especially in symbiosis with common bean (Phaseolus vulgaris L.). Genes putatively related to the synthesis of indole acetic acid (IAA) have been found in the symbiotic plasmid of CIAT 899, in the vicinity of the regulatory nodulation gene nodD5, and, in this study, we obtained mutants for two of these genes, y4wF and tidC (R. tropiciindole-3-pyruvic acid decarboxylase), and investigated their expression in the absence and presence of tryptophan (TRP) and apigenin (API). In general, mutations of both genes increased exopolysaccharide (EPS) synthesis and did not affect swimming or surface motility; mutations also delayed nodule formation, but increased competitiveness. We found that the indole-3-acetamide (IAM) pathway was active in CIAT 899 and not affected by the mutations, and-noteworthy-that API was required to activate the tryptamine (TAM) and the indol-3-pyruvic acid (IPyA) pathways in all strains, particularly in the mutants. High up-regulation of y4wF and tidC genes was observed in both the wild-type and the mutant strains in the presence of API. The results obtained revealed an intriguing relationship between IAA metabolism and nod-gene-inducing activity in R. tropici CIAT 899. We discuss the IAA pathways, and, based on our results, we attribute functions to the y4wF and tidC genes of R. tropici.
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Sinorhizobium meliloti Chemoreceptor McpV Senses Short-Chain Carboxylates via Direct Binding. J Bacteriol 2018; 200:JB.00519-18. [PMID: 30201781 DOI: 10.1128/jb.00519-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 09/04/2018] [Indexed: 11/20/2022] Open
Abstract
Sinorhizobium meliloti is a soil-dwelling endosymbiont of alfalfa that has eight chemoreceptors to sense environmental stimuli during its free-living state. The functions of two receptors have been characterized, with McpU and McpX serving as general amino acid and quaternary ammonium compound sensors, respectively. Both receptors use a dual Cache (calcium channels and chemotaxis receptors) domain for ligand binding. We identified that the ligand-binding periplasmic region (PR) of McpV contains a single Cache domain. Homology modeling revealed that McpVPR is structurally similar to a sensor domain of a chemoreceptor with unknown function from Anaeromyxobacter dehalogenans, which crystallized with acetate in its binding pocket. We therefore assayed McpV for carboxylate binding and S. meliloti for carboxylate sensing. Differential scanning fluorimetry identified 10 potential ligands for McpVPR Nine of these are monocarboxylates with chain lengths between two and four carbons. We selected seven compounds for capillary assay analysis, which established positive chemotaxis of the S. meliloti wild type, with concentrations of peak attraction at 1 mM for acetate, propionate, pyruvate, and glycolate, and at 100 mM for formate and acetoacetate. Deletion of mcpV or mutation of residues essential for ligand coordination abolished positive chemotaxis to carboxylates. Using microcalorimetry, we determined that dissociation constants of the seven ligands with McpVPR were in the micromolar range. An McpVPR variant with a mutation in the ligand coordination site displayed no binding to isobutyrate or propionate. Of all the carboxylates tested as attractants, only glycolate was detected in alfalfa seed exudates. This work examines the relevance of carboxylates and their sensor to the rhizobium-legume interaction.IMPORTANCE Legumes share a unique association with certain soil-dwelling bacteria known broadly as rhizobia. Through concerted interorganismal communication, a legume allows intracellular infection by its cognate rhizobial species. The plant then forms an organ, the root nodule, dedicated to housing and supplying fixed carbon and nutrients to the bacteria. In return, the engulfed rhizobia, differentiated into bacteroids, fix atmospheric N2 into ammonium for the plant host. This interplay is of great benefit to the cultivation of legumes, such as alfalfa and soybeans, and is initiated by chemotaxis to the host plant. This study on carboxylate chemotaxis contributes to the understanding of rhizobial survival and competition in the rhizosphere and aids the development of commercial inoculants.
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Kang W, Xu L, Jiang Z, Shi S. Genetic diversity and symbiotic efficiency difference of endophytic rhizobia of Medicago sativa. Can J Microbiol 2018; 65:68-83. [PMID: 30273494 DOI: 10.1139/cjm-2018-0158] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Research on rhizobium diversity has paved the way for diversification of rhizobial germplasm resources. Seventy-three endophytic bacterial isolates were collected from seven tissues of five alfalfa cultivars in three geographic locations in Gansu, China. Restriction fragment length polymorphism (RFLP) fingerprinting of 16S rRNA and analysis of concatenated sequence of three housekeeping genes (atpD, glnII, and recA) and two symbiotic genes (nodC and nifH) were used for strain identification. Results showed that the endophytic strains were genetically diverse at different taxonomic levels, and Ensifer meliloti (31) and Agrobacterium radiobacter (12) are common Medicago sativa endophytic bacteria in Gansu, China. The nifH genes (97%-98% sequence identity) of E. meliloti strains were more diverse than the nodC genes (99%-100% sequence identity), even though the strains evolved from a common ancestor. The degree of dispersion of symbiotic phenotypes of E. meliloti strains on M. sativa 'Gannong No. 3', 'Gannong No. 9', and 'Qingshui' was much less than that on M. sativa 'Longzhong' and 'WL168HQ'. This suggested that the symbiotic efficiency of E. meliloti strains on the former three alfalfa cultivars was similar but on the latter two was discrepant. Their symbiotic efficiency differed primarily according to alfalfa cultivars and, to a lesser extent, to the tested strains, indicating the difference in the sensitivity of different alfalfa cultivars to rhizobial strains.
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Affiliation(s)
- Wenjuan Kang
- a College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, P.R. China
| | - Lin Xu
- b College of Agriculture and Biotechnology, Hexi University, Zhangye 734000, P.R. China
| | - Zhehao Jiang
- a College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, P.R. China
| | - Shangli Shi
- a College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, P.R. China.,c Key Laboratory of Grassland Ecosystem of Ministry of Education, Lanzhou 730070, P.R. China
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Hu Y, Jiao J, Liu LX, Sun YW, Chen WF, Sui XH, Chen WX, Tian CF. Evidence for Phosphate Starvation of Rhizobia without Terminal Differentiation in Legume Nodules. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2018; 31:1060-1068. [PMID: 29663866 DOI: 10.1094/mpmi-02-18-0031-r] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Phosphate homeostasis is tightly modulated in all organisms, including bacteria, which harbor both high- and low-affinity transporters acting under conditions of fluctuating phosphate levels. It was thought that nitrogen-fixing rhizobia, named bacteroids, inhabiting root nodules of legumes are not phosphate limited. Here, we show that the high-affinity phosphate transporter PstSCAB, rather than the low-affinity phosphate transporter Pit, is essential for effective nitrogen fixation of Sinorhizobium fredii in soybean nodules. Symbiotic and growth defects of the pst mutant can be effectively restored by knocking out PhoB, the transcriptional repressor of pit. The pst homologs of representative rhizobia were actively transcribed in bacteroids without terminal differentiation in nodules of diverse legumes (soybean, pigeonpea, cowpea, common bean, and Sophora flavescens) but exhibited a basal expression level in terminally differentiated bacteroids (alfalfa, pea, and peanut). Rhizobium leguminosarum bv. viciae Rlv3841 undergoes characteristic nonterminal and terminal differentiations in nodules of S. flavescens and pea, respectively. The pst mutant of Rlv3841 showed impaired adaptation to the nodule environment of S. flavescens but was indistinguishable from the wild-type strain in pea nodules. Taken together, root nodule rhizobia can be either phosphate limited or nonlimited regarding the rhizobial differentiation fate, which is a host-dependent feature.
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Affiliation(s)
- Yue Hu
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, Rhizobium Research Center, and College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Jian Jiao
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, Rhizobium Research Center, and College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Li Xue Liu
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, Rhizobium Research Center, and College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Yan Wei Sun
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, Rhizobium Research Center, and College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Wen Feng Chen
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, Rhizobium Research Center, and College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Xin Hua Sui
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, Rhizobium Research Center, and College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Wen Xin Chen
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, Rhizobium Research Center, and College of Biological Sciences, China Agricultural University, 100193, Beijing, China
| | - Chang Fu Tian
- State Key Laboratory of Agrobiotechnology, MOA Key Laboratory of Soil Microbiology, Rhizobium Research Center, and College of Biological Sciences, China Agricultural University, 100193, Beijing, China
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Mutation in the pssZ Gene Negatively Impacts Exopolysaccharide Synthesis, Surface Properties, and Symbiosis of Rhizobium leguminosarum bv. trifolii with Clover. Genes (Basel) 2018; 9:genes9070369. [PMID: 30041474 PMCID: PMC6071215 DOI: 10.3390/genes9070369] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/05/2018] [Accepted: 07/16/2018] [Indexed: 12/19/2022] Open
Abstract
Rhizobium leguminosarum bv. trifolii is a soil bacterium capable of establishing a nitrogen-fixing symbiosis with clover plants (Trifolium spp.). This bacterium secretes large amounts of acidic exopolysaccharide (EPS), which plays an essential role in the symbiotic interaction with the host plant. This polymer is biosynthesized by a multi-enzymatic complex located in the bacterial inner membrane, whose components are encoded by a large chromosomal gene cluster, called Pss-I. In this study, we characterize R. leguminosarum bv. trifolii strain Rt297 that harbors a Tn5 transposon insertion located in the pssZ gene from the Pss-I region. This gene codes for a protein that shares high identity with bacterial serine/threonine protein phosphatases. We demonstrated that the pssZ mutation causes pleiotropic effects in rhizobial cells. Strain Rt297 exhibited several physiological and symbiotic defects, such as lack of EPS production, reduced growth kinetics and motility, altered cell-surface properties, and failure to infect the host plant. These data indicate that the protein encoded by the pssZ gene is indispensable for EPS synthesis, but also required for proper functioning of R. leguminosarum bv. trifolii cells.
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Calatrava-Morales N, McIntosh M, Soto MJ. Regulation Mediated by N-Acyl Homoserine Lactone Quorum Sensing Signals in the Rhizobium-Legume Symbiosis. Genes (Basel) 2018; 9:genes9050263. [PMID: 29783703 PMCID: PMC5977203 DOI: 10.3390/genes9050263] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/15/2018] [Accepted: 05/15/2018] [Indexed: 02/06/2023] Open
Abstract
Soil-dwelling bacteria collectively referred to as rhizobia synthesize and perceive N-acyl-homoserine lactone (AHL) signals to regulate gene expression in a population density-dependent manner. AHL-mediated signaling in these bacteria regulates several functions which are important for the establishment of nitrogen-fixing symbiosis with legume plants. Moreover, rhizobial AHL act as interkingdom signals triggering plant responses that impact the plant-bacteria interaction. Both the regulatory mechanisms that control AHL synthesis in rhizobia and the set of bacterial genes and associated traits under quorum sensing (QS) control vary greatly among the rhizobial species. In this article, we focus on the well-known QS system of the alfalfa symbiont Sinorhizobium(Ensifer)meliloti. Bacterial genes, environmental factors and transcriptional and posttranscriptional regulatory mechanisms that control AHL production in this Rhizobium, as well as the effects of the signaling molecule on bacterial phenotypes and plant responses will be reviewed. Current knowledge of S. meliloti QS will be compared with that of other rhizobia. Finally, participation of the legume host in QS by interfering with rhizobial AHL perception through the production of molecular mimics will also be addressed.
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Affiliation(s)
- Nieves Calatrava-Morales
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC; Granada 18008, Spain.
| | - Matthew McIntosh
- Institut für Mikrobiologie und Molekularbiologie, Universität Giessen, 35392 Giessen, Germany.
| | - María J Soto
- Departamento de Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC; Granada 18008, Spain.
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Belin BJ, Busset N, Giraud E, Molinaro A, Silipo A, Newman DK. Hopanoid lipids: from membranes to plant-bacteria interactions. Nat Rev Microbiol 2018; 16:304-315. [PMID: 29456243 PMCID: PMC6087623 DOI: 10.1038/nrmicro.2017.173] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Lipid research represents a frontier for microbiology, as showcased by hopanoid lipids. Hopanoids, which resemble sterols and are found in the membranes of diverse bacteria, have left an extensive molecular fossil record. They were first discovered by petroleum geologists. Today, hopanoid-producing bacteria remain abundant in various ecosystems, such as the rhizosphere. Recently, great progress has been made in our understanding of hopanoid biosynthesis, facilitated in part by technical advances in lipid identification and quantification. A variety of genetically tractable, hopanoid-producing bacteria have been cultured, and tools to manipulate hopanoid biosynthesis and detect hopanoids are improving. However, we still have much to learn regarding how hopanoid production is regulated, how hopanoids act biophysically and biochemically, and how their production affects bacterial interactions with other organisms, such as plants. The study of hopanoids thus offers rich opportunities for discovery.
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Affiliation(s)
- Brittany J. Belin
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Nicolas Busset
- Institut de Recherche pour le Développement, LSTM, UMR IRD, SupAgro, INRA, University of Montpellier, CIRAD, France
| | - Eric Giraud
- Institut de Recherche pour le Développement, LSTM, UMR IRD, SupAgro, INRA, University of Montpellier, CIRAD, France
| | - Antonio Molinaro
- Department of Chemical Sciences, University of Naples Federico II, Napoli, Italy
| | - Alba Silipo
- Department of Chemical Sciences, University of Naples Federico II, Napoli, Italy
| | - Dianne K. Newman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
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Toro N, Martínez-Abarca F, Molina-Sánchez MD, García-Rodríguez FM, Nisa-Martínez R. Contribution of Mobile Group II Introns to Sinorhizobium meliloti Genome Evolution. Front Microbiol 2018; 9:627. [PMID: 29670598 PMCID: PMC5894124 DOI: 10.3389/fmicb.2018.00627] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 03/19/2018] [Indexed: 12/26/2022] Open
Abstract
Mobile group II introns are ribozymes and retroelements that probably originate from bacteria. Sinorhizobium meliloti, the nitrogen-fixing endosymbiont of legumes of genus Medicago, harbors a large number of these retroelements. One of these elements, RmInt1, has been particularly successful at colonizing this multipartite genome. Many studies have improved our understanding of RmInt1 and phylogenetically related group II introns, their mobility mechanisms, spread and dynamics within S. meliloti and closely related species. Although RmInt1 conserves the ancient retroelement behavior, its evolutionary history suggests that this group II intron has played a role in the short- and long-term evolution of the S. meliloti genome. We will discuss its proposed role in genome evolution by controlling the spread and coexistence of potentially harmful mobile genetic elements, by ectopic transposition to different genetic loci as a source of early genomic variation and by generating sequence variation after a very slow degradation process, through intron remnants that may have continued to evolve, contributing to bacterial speciation.
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Affiliation(s)
- Nicolás Toro
- Structure, Dynamics and Function of Rhizobacterial Genomes (Grupo de Ecología Genética de la Rizosfera), Department of Soil Microbiology and Symbiotic Systems, Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Granada, Spain
| | - Francisco Martínez-Abarca
- Structure, Dynamics and Function of Rhizobacterial Genomes (Grupo de Ecología Genética de la Rizosfera), Department of Soil Microbiology and Symbiotic Systems, Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Granada, Spain
| | - María D Molina-Sánchez
- Structure, Dynamics and Function of Rhizobacterial Genomes (Grupo de Ecología Genética de la Rizosfera), Department of Soil Microbiology and Symbiotic Systems, Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Granada, Spain
| | - Fernando M García-Rodríguez
- Structure, Dynamics and Function of Rhizobacterial Genomes (Grupo de Ecología Genética de la Rizosfera), Department of Soil Microbiology and Symbiotic Systems, Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Granada, Spain
| | - Rafael Nisa-Martínez
- Structure, Dynamics and Function of Rhizobacterial Genomes (Grupo de Ecología Genética de la Rizosfera), Department of Soil Microbiology and Symbiotic Systems, Consejo Superior de Investigaciones Científicas, Estación Experimental del Zaidín, Granada, Spain
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40
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Kang W, Shi S, Xu L. Diversity and symbiotic divergence of endophytic and non-endophytic rhizobia of Medicago sativa. ANN MICROBIOL 2018. [DOI: 10.1007/s13213-018-1333-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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41
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Ankrah NYD, Douglas AE. Nutrient factories: metabolic function of beneficial microorganisms associated with insects. Environ Microbiol 2018. [DOI: 10.1111/1462-2920.14097] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
| | - Angela E. Douglas
- Department of MicrobiologyCornell UniversityIthaca NY14853 USA
- Department of Molecular Biology and GeneticsCornell UniversityIthaca NY14853 USA
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Lang C, Smith LS, Haney CH, Long SR. Characterization of Novel Plant Symbiosis Mutants Using a New Multiple Gene-Expression Reporter Sinorhizobium meliloti Strain. FRONTIERS IN PLANT SCIENCE 2018; 9:76. [PMID: 29467773 PMCID: PMC5808326 DOI: 10.3389/fpls.2018.00076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/15/2018] [Indexed: 06/08/2023]
Abstract
The formation of nitrogen fixing root nodules by Medicago truncatula and Sinorhizobium meliloti requires communication between both organisms and coordinated differentiation of plant and bacterial cells. After an initial signal exchange, the bacteria invade the tissue of the growing nodule via plant-derived tubular structures, called infection threads. The bacteria are released from the infection threads into invasion-competent plant cells, where they differentiate into nitrogen-fixing bacteroids. Both organisms undergo dramatic transcriptional, metabolic and morphological changes during nodule development. To identify plant processes that are essential for the formation of nitrogen fixing nodules after nodule development has been initiated, large scale mutageneses have been conducted to discover underlying plant symbiosis genes. Such screens yield numerous uncharacterized plant lines with nitrogen fixation deficient nodules. In this study, we report construction of a S. meliloti strain carrying four distinct reporter constructs to reveal stages of root nodule development. The strain contains a constitutively expressed lacZ reporter construct; a PexoY-mTFP fusion that is expressed in infection threads but not in differentiated bacteroids; a PbacA-mcherry construct that is expressed in infection threads and during bacteroid differentiation; and a PnifH-uidA construct that is expressed during nitrogen fixation. We used this strain together with fluorescence microscopy to study nodule development over time in wild type nodules and to characterize eight plant mutants from a fast neutron bombardment screen. Based on the signal intensity and the localization patterns of the reporter genes, we grouped mutants with similar phenotypes and placed them in a developmental context.
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Affiliation(s)
| | | | | | - Sharon R. Long
- Gilbert Lab, Department of Biology, Stanford University, Stanford, CA, United States
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Coba de la Peña T, Fedorova E, Pueyo JJ, Lucas MM. The Symbiosome: Legume and Rhizobia Co-evolution toward a Nitrogen-Fixing Organelle? FRONTIERS IN PLANT SCIENCE 2018; 8:2229. [PMID: 29403508 PMCID: PMC5786577 DOI: 10.3389/fpls.2017.02229] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 12/19/2017] [Indexed: 05/21/2023]
Abstract
In legume nodules, symbiosomes containing endosymbiotic rhizobial bacteria act as temporary plant organelles that are responsible for nitrogen fixation, these bacteria develop mutual metabolic dependence with the host legume. In most legumes, the rhizobia infect post-mitotic cells that have lost their ability to divide, although in some nodules cells do maintain their mitotic capacity after infection. Here, we review what is currently known about legume symbiosomes from an evolutionary and developmental perspective, and in the context of the different interactions between diazotroph bacteria and eukaryotes. As a result, it can be concluded that the symbiosome possesses organelle-like characteristics due to its metabolic behavior, the composite origin and differentiation of its membrane, the retargeting of host cell proteins, the control of microsymbiont proliferation and differentiation by the host legume, and the cytoskeletal dynamics and symbiosome segregation during the division of rhizobia-infected cells. Different degrees of symbiosome evolution can be defined, specifically in relation to rhizobial infection and to the different types of nodule. Thus, our current understanding of the symbiosome suggests that it might be considered a nitrogen-fixing link in organelle evolution and that the distinct types of legume symbiosomes could represent different evolutionary stages toward the generation of a nitrogen-fixing organelle.
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Affiliation(s)
- Teodoro Coba de la Peña
- Instituto de Ciencias Agrarias ICA-CSIC, Madrid, Spain
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), La Serena, Chile
| | - Elena Fedorova
- Instituto de Ciencias Agrarias ICA-CSIC, Madrid, Spain
- K. A. Timiryazev Institute of Plant Physiology, Russian Academy of Science, Moscow, Russia
| | - José J Pueyo
- Instituto de Ciencias Agrarias ICA-CSIC, Madrid, Spain
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Maire J, Vincent-Monégat C, Masson F, Zaidman-Rémy A, Heddi A. An IMD-like pathway mediates both endosymbiont control and host immunity in the cereal weevil Sitophilus spp. MICROBIOME 2018; 6:6. [PMID: 29310713 PMCID: PMC5759881 DOI: 10.1186/s40168-017-0397-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 12/28/2017] [Indexed: 05/08/2023]
Abstract
Many insects developing on nutritionally unbalanced diets have evolved symbiotic associations with vertically transmitted intracellular bacteria (endosymbionts) that provide them with metabolic components, thereby improving the host's abilities to thrive on such poor ecological niches. While host-endosymbiont coevolutionary constraints are known to entail massive genomic changes in the microbial partner, host's genomic evolution remains elusive, particularly with regard to the immune system. In the cereal weevil Sitophilus spp., which houses Sodalis pierantonius, endosymbionts are secluded in specialized host cells, the bacteriocytes that group together as an organ, the bacteriome. We previously reported that at standard conditions, the bacteriome highly expresses the coleoptericin A (colA) antimicrobial peptide (AMP), which was shown to prevent endosymbiont escape from the bacteriocytes. However, following the insect systemic infection by pathogens, the bacteriome upregulates a cocktail of AMP encoding genes, including colA. The regulations that allow these contrasted immune responses remain unknown. In this short report, we provide evidence that an IMD-like pathway is conserved in two sibling species of cereal weevils, Sitophilus oryzae and Sitophilus zeamais. RNA interference (RNAi) experiments showed that imd and relish genes are essential for (i) colA expression in the bacteriome under standard conditions, (ii) AMP up-regulation in the bacteriome following a systemic immune challenge, and (iii) AMP systemic induction following an immune challenge. Histological analyses also showed that relish inhibition by RNAi resulted in endosymbiont escape from the bacteriome, strengthening the involvement of an IMD-like pathway in endosymbiont control. We conclude that Sitophilus' IMD-like pathway mediates both the bacteriome immune program involved in endosymbiont seclusion within the bacteriocytes and the systemic and local immune responses to exogenous challenges. This work provides a striking example of how a conserved immune pathway, initially described as essential in pathogen clearance, also functions in the control of mutualistic associations.
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Affiliation(s)
- Justin Maire
- Univ Lyon, INSA-Lyon, INRA, BF2i, UMR0203, F-69621, Villeurbanne, France
| | | | - Florent Masson
- Univ Lyon, INSA-Lyon, INRA, BF2i, UMR0203, F-69621, Villeurbanne, France
- Present address: Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 19, 1015, Lausanne, Switzerland
| | - Anna Zaidman-Rémy
- Univ Lyon, INSA-Lyon, INRA, BF2i, UMR0203, F-69621, Villeurbanne, France
| | - Abdelaziz Heddi
- Univ Lyon, INSA-Lyon, INRA, BF2i, UMR0203, F-69621, Villeurbanne, France.
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Wang Q, Liu J, Zhu H. Genetic and Molecular Mechanisms Underlying Symbiotic Specificity in Legume-Rhizobium Interactions. FRONTIERS IN PLANT SCIENCE 2018; 9:313. [PMID: 29593768 PMCID: PMC5854654 DOI: 10.3389/fpls.2018.00313] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 02/23/2018] [Indexed: 05/20/2023]
Abstract
Legumes are able to form a symbiotic relationship with nitrogen-fixing soil bacteria called rhizobia. The result of this symbiosis is to form nodules on the plant root, within which the bacteria can convert atmospheric nitrogen into ammonia that can be used by the plant. Establishment of a successful symbiosis requires the two symbiotic partners to be compatible with each other throughout the process of symbiotic development. However, incompatibility frequently occurs, such that a bacterial strain is unable to nodulate a particular host plant or forms nodules that are incapable of fixing nitrogen. Genetic and molecular mechanisms that regulate symbiotic specificity are diverse, involving a wide range of host and bacterial genes/signals with various modes of action. In this review, we will provide an update on our current knowledge of how the recognition specificity has evolved in the context of symbiosis signaling and plant immunity.
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Santi C, Molesini B, Guzzo F, Pii Y, Vitulo N, Pandolfini T. Genome-Wide Transcriptional Changes and Lipid Profile Modifications Induced by Medicago truncatula N5 Overexpression at an Early Stage of the Symbiotic Interaction with Sinorhizobium meliloti. Genes (Basel) 2017; 8:E396. [PMID: 29257077 PMCID: PMC5748714 DOI: 10.3390/genes8120396] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/06/2017] [Accepted: 12/11/2017] [Indexed: 12/23/2022] Open
Abstract
Plant lipid-transfer proteins (LTPs) are small basic secreted proteins, which are characterized by lipid-binding capacity and are putatively involved in lipid trafficking. LTPs play a role in several biological processes, including the root nodule symbiosis. In this regard, the Medicago truncatula nodulin 5 (MtN5) LTP has been proved to positively regulate the nodulation capacity, controlling rhizobial infection and nodule primordia invasion. To better define the lipid transfer protein MtN5 function during the symbiosis, we produced MtN5-downregulated and -overexpressing plants, and we analysed the transcriptomic changes occurring in the roots at an early stage of Sinorhizobium meliloti infection. We also carried out the lipid profile analysis of wild type (WT) and MtN5-overexpressing roots after rhizobia infection. The downregulation of MtN5 increased the root hair curling, an early event of rhizobia infection, and concomitantly induced changes in the expression of defence-related genes. On the other hand, MtN5 overexpression favoured the invasion of the nodules by rhizobia and determined in the roots the modulation of genes that are involved in lipid transport and metabolism as well as an increased content of lipids, especially galactolipids that characterize the symbiosome membranes. Our findings suggest the potential participation of LTPs in the synthesis and rearrangement of membranes occurring during the formation of the infection threads and the symbiosome membrane.
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Affiliation(s)
- Chiara Santi
- Department of Biotechnology, University of Verona, 37134 Verona, Italy.
| | - Barbara Molesini
- Department of Biotechnology, University of Verona, 37134 Verona, Italy.
| | - Flavia Guzzo
- Department of Biotechnology, University of Verona, 37134 Verona, Italy.
| | - Youry Pii
- Faculty of Science and Technology, Free University of Bozen-Bolzano, 39100 Bolzano BZ, Italy.
| | - Nicola Vitulo
- Department of Biotechnology, University of Verona, 37134 Verona, Italy.
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Marczak M, Mazur A, Koper P, Żebracki K, Skorupska A. Synthesis of Rhizobial Exopolysaccharides and Their Importance for Symbiosis with Legume Plants. Genes (Basel) 2017; 8:E360. [PMID: 29194398 PMCID: PMC5748678 DOI: 10.3390/genes8120360] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/26/2017] [Accepted: 11/29/2017] [Indexed: 12/25/2022] Open
Abstract
Rhizobia dwell and multiply in the soil and represent a unique group of bacteria able to enter into a symbiotic interaction with plants from the Fabaceae family and fix atmospheric nitrogen inside de novo created plant organs, called nodules. One of the key determinants of the successful interaction between these bacteria and plants are exopolysaccharides, which represent species-specific homo- and heteropolymers of different carbohydrate units frequently decorated by non-carbohydrate substituents. Exopolysaccharides are typically built from repeat units assembled by the Wzx/Wzy-dependent pathway, where individual subunits are synthesized in conjunction with the lipid anchor undecaprenylphosphate (und-PP), due to the activity of glycosyltransferases. Complete oligosaccharide repeat units are transferred to the periplasmic space by the activity of the Wzx flippase, and, while still being anchored in the membrane, they are joined by the polymerase Wzy. Here we have focused on the genetic control over the process of exopolysaccharides (EPS) biosynthesis in rhizobia, with emphasis put on the recent advancements in understanding the mode of action of the key proteins operating in the pathway. A role played by exopolysaccharide in Rhizobium-legume symbiosis, including recent data confirming the signaling function of EPS, is also discussed.
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Affiliation(s)
- Małgorzata Marczak
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
| | - Andrzej Mazur
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
| | - Piotr Koper
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
| | - Kamil Żebracki
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
| | - Anna Skorupska
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
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Busset N, Di Lorenzo F, Palmigiano A, Sturiale L, Gressent F, Fardoux J, Gully D, Chaintreuil C, Molinaro A, Silipo A, Giraud E. The Very Long Chain Fatty Acid (C 26:25OH) Linked to the Lipid A Is Important for the Fitness of the Photosynthetic Bradyrhizobium Strain ORS278 and the Establishment of a Successful Symbiosis with Aeschynomene Legumes. Front Microbiol 2017; 8:1821. [PMID: 28983292 PMCID: PMC5613085 DOI: 10.3389/fmicb.2017.01821] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 09/06/2017] [Indexed: 11/13/2022] Open
Abstract
In rhizobium strains, the lipid A is modified by the addition of a very long-chain fatty acid (VLCFA) shown to play an important role in rigidification of the outer membrane, thereby facilitating their dual life cycle, outside and inside the plant. In Bradyrhizobium strains, the lipid A is more complex with the presence of at least two VLCFAs, one covalently linked to a hopanoid molecule, but the importance of these modifications is not well-understood. In this study, we identified a cluster of VLCFA genes in the photosynthetic Bradyrhizobium strain ORS278, which nodulates Aeschynomene plants in a Nod factor-independent process. We tried to mutate the different genes of the VLCFA gene cluster to prevent the synthesis of the VLCFAs, but only one mutant in the lpxXL gene encoding an acyltransferase was obtained. Structural analysis of the lipid A showed that LpxXL is involved in the transfer of the C26:25OH VLCFA to the lipid A but not in the one of the C30:29OH VLCFA which harbors the hopanoid molecule. Despite maintaining the second VLCFA, the ability of the mutant to cope with various stresses (low pH, high temperature, high osmolarity, and antimicrobial peptides) and to establish an efficient nitrogen-fixing symbiosis was drastically reduced. In parallel, we investigated whether the BRADO0045 gene, which encodes a putative acyltransferase displaying a weak identity with the apo-lipoprotein N-acyltransferase Lnt, could be involved in the transfer of the C30:29OH VLCFA to the lipid A. Although the mutant exhibited phenotypes similar to the lpxXL mutant, no difference in the lipid A structure was observed from that in the wild-type strain, indicating that this gene is not involved in the modification of lipid A. Our results advance our knowledge of the biosynthesis pathway and the role of VLCFAs-modified lipid A in free-living and symbiotic states of Bradyrhizobium strains.
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Affiliation(s)
- Nicolas Busset
- Institut de Recherche pour le Développement, LSTM, UMR IRD, SupAgro, INRA, Université de Montpellier, CIRADMontpellier, France
| | - Flaviana Di Lorenzo
- Dipartimento di Scienze Chimiche, Complesso Universitario Monte Sant'Angelo, Università di Napoli Federico IINaples, Italy
| | - Angelo Palmigiano
- Istituto per i Polimeri, Compositi e Biomateriali IPCB, Consiglio Nazionale delle RicercheCatania, Italy
| | - Luisa Sturiale
- Istituto per i Polimeri, Compositi e Biomateriali IPCB, Consiglio Nazionale delle RicercheCatania, Italy
| | - Frederic Gressent
- Institut de Recherche pour le Développement, LSTM, UMR IRD, SupAgro, INRA, Université de Montpellier, CIRADMontpellier, France
| | - Joël Fardoux
- Institut de Recherche pour le Développement, LSTM, UMR IRD, SupAgro, INRA, Université de Montpellier, CIRADMontpellier, France
| | - Djamel Gully
- Institut de Recherche pour le Développement, LSTM, UMR IRD, SupAgro, INRA, Université de Montpellier, CIRADMontpellier, France
| | - Clémence Chaintreuil
- Institut de Recherche pour le Développement, LSTM, UMR IRD, SupAgro, INRA, Université de Montpellier, CIRADMontpellier, France
| | - Antonio Molinaro
- Dipartimento di Scienze Chimiche, Complesso Universitario Monte Sant'Angelo, Università di Napoli Federico IINaples, Italy
| | - Alba Silipo
- Dipartimento di Scienze Chimiche, Complesso Universitario Monte Sant'Angelo, Università di Napoli Federico IINaples, Italy
| | - Eric Giraud
- Institut de Recherche pour le Développement, LSTM, UMR IRD, SupAgro, INRA, Université de Montpellier, CIRADMontpellier, France
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Burghardt LT, Guhlin J, Chun CL, Liu J, Sadowsky MJ, Stupar RM, Young ND, Tiffin P. Transcriptomic basis of genome by genome variation in a legume‐rhizobia mutualism. Mol Ecol 2017; 26:6122-6135. [DOI: 10.1111/mec.14285] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 07/10/2017] [Indexed: 02/01/2023]
Affiliation(s)
- Liana T. Burghardt
- Department of Plant and Microbial Biology University of Minnesota St. Paul MN USA
| | - Joseph Guhlin
- Department of Plant and Microbial Biology University of Minnesota St. Paul MN USA
| | - Chan Lan Chun
- BioTechnology Institute University of Minnesota St. Paul MN USA
| | - Junqi Liu
- Department of Agronomy and Plant Genetics University of Minnesota St. Paul MN USA
| | | | - Robert M. Stupar
- Department of Agronomy and Plant Genetics University of Minnesota St. Paul MN USA
| | - Nevin D. Young
- Department of Plant and Microbial Biology University of Minnesota St. Paul MN USA
- Department of Plant Pathology University of Minnesota St. Paul MN USA
| | - Peter Tiffin
- Department of Plant and Microbial Biology University of Minnesota St. Paul MN USA
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50
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Marek-Kozaczuk M, Wdowiak-Wróbel S, Kalita M, Chernetskyy M, Deryło K, Tchórzewski M, Skorupska A. Host-dependent symbiotic efficiency of Rhizobium leguminosarum bv. trifolii strains isolated from nodules of Trifolium rubens. Antonie van Leeuwenhoek 2017; 110:1729-1744. [PMID: 28791535 PMCID: PMC5676844 DOI: 10.1007/s10482-017-0922-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/29/2017] [Indexed: 11/28/2022]
Abstract
Trifolium rubens L., commonly known as the red feather clover, is capable of symbiotic interactions with rhizobia. Up to now, no specific symbionts of T. rubens and their symbiotic compatibility with Trifolium spp. have been described. We characterized the genomic diversity of T. rubens symbionts by analyses of plasmid profiles and BOX-PCR. The phylogeny of T. rubens isolates was inferred based on the nucleotide sequences of 16S rRNA and two core genes (atpD, recA). The nodC phylogeny allowed classification of rhizobia nodulating T. rubens as Rhizobium leguminosarum symbiovar trifolii (Rlt). The symbiotic efficiency of the Rlt isolates was determined on four clover species: T. rubens, T. pratense, T. repens and T. resupinatum. We determined that Rlt strains formed mostly inefficient symbiosis with their native host plant T. rubens and weakly effective (sub-optimal) symbiosis with T. repens and T. pratense. The same Rlt strains were fully compatible in the symbiosis with T. resupinatum. T. rubens did not exhibit strict selectivity in regard to the symbionts and rhizobia closely related to Rhizobium grahamii, Rhizobium galegae and Agrobacterium radiobacter, which did not nodulate Trifolium spp., were found amongst T. rubens nodule isolates.
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Affiliation(s)
- Monika Marek-Kozaczuk
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland.
| | - Sylwia Wdowiak-Wróbel
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Michał Kalita
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Mykhaylo Chernetskyy
- The Botanic Garden of Maria Curie-Skłodowska University, Sławinkowska 3, 20-810, Lublin, Poland
| | - Kamil Deryło
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Marek Tchórzewski
- Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Anna Skorupska
- Department of Genetics and Microbiology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
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