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Bharti A, Maheshwari HS, Garg S, Anwar K, Pareek A, Satpute G, Prakash A, Sharma MP. Exploring potential soybean bradyrhizobia from high trehalose-accumulating soybean genotypes for improved symbiotic effectiveness in soybean. Int Microbiol 2023; 26:973-987. [PMID: 37036547 DOI: 10.1007/s10123-023-00351-3] [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: 11/11/2022] [Revised: 03/20/2023] [Accepted: 03/25/2023] [Indexed: 04/11/2023]
Abstract
Drought is the most important factor limiting the activity of rhizobia during N-fixation and plant growth. In the present study, we isolated Bradyrhizobium spp. from root nodules of higher trehalose-accumulating soybean genotypes and examined for moisture stress tolerance on a gradient of polyethylene glycol (PEG 6000) amended in yeast extract mannitol (YEM) broth. In addition, the bradyrhizobial strains were also evaluated for symbiotic effectiveness on soybean. Based on 16S rDNA gene sequences, four bradyrhizobial species were recovered from high trehalose-accumulating genotypes, i.e., two Bradyrhizobium liaoningense strains (accession number KX230053, KX230054) from EC 538828 and PK-472, respectively, one Bradyrhizobium daqingense (accession number KX230052) from PK-472, and one Bradyrhizobium kavangense (accession number MN197775) from Valder genotype having low trehalose. These strains, along with two native strains, viz., Bradyrhizobium japonicum (JF792425), Bradyrhizobium liaoningense (JF792426), and one commercial rhizobium, were studied for nodulation, leghaemoglobin, and N-fixation abilities on soybean under sterilized sand microcosm conditions in a completely randomized design. Among all the strains, D-4A (B. daqingense) followed by D-4B (B. liaoningense) was found to have significantly higher nodulation traits and acetylene reduction assay (ARA) activity when compared to other strains and commercial rhizobia. The bradyrhizobia isolates showed plant growth promotion traits such as indole acetic acid (IAA), exopolysaccharide (EPS), and siderophore production, phosphate-solubilizing potential, and proline accumulation. The novel species B. daqingense was reported for the first time from Indian soil and observed to be a potential candidate strain and should be evaluated for conferring drought tolerance in soybean under simulated stress conditions.
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Affiliation(s)
- Abhishek Bharti
- ICAR-Indian Institute of Soybean Research, Khandwa Road, Indore, 452001, India
- Department of Microbiology, Barkatullah University, Bhopal, 462026, India
| | - Hemant S Maheshwari
- ICAR-Indian Institute of Soybean Research, Khandwa Road, Indore, 452001, India
| | - Shivani Garg
- ICAR-Indian Institute of Soybean Research, Khandwa Road, Indore, 452001, India
| | - Khalid Anwar
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Ashwani Pareek
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
- National Agri-Food Biotechnology Institute (NABI), Mohali, 140308, Punjab, India
| | - Gyanesh Satpute
- ICAR-Indian Institute of Soybean Research, Khandwa Road, Indore, 452001, India
| | - Anil Prakash
- Department of Microbiology, Barkatullah University, Bhopal, 462026, India
| | - Mahaveer P Sharma
- ICAR-Indian Institute of Soybean Research, Khandwa Road, Indore, 452001, India.
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Sharma MP, Grover M, Chourasiya D, Bharti A, Agnihotri R, Maheshwari HS, Pareek A, Buyer JS, Sharma SK, Schütz L, Mathimaran N, Singla-Pareek SL, Grossman JM, Bagyaraj DJ. Deciphering the Role of Trehalose in Tripartite Symbiosis Among Rhizobia, Arbuscular Mycorrhizal Fungi, and Legumes for Enhancing Abiotic Stress Tolerance in Crop Plants. Front Microbiol 2020; 11:509919. [PMID: 33042042 PMCID: PMC7527417 DOI: 10.3389/fmicb.2020.509919] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 08/20/2020] [Indexed: 01/31/2023] Open
Abstract
Drought is a critical factor limiting the productivity of legumes worldwide. Legumes can enter into a unique tripartite symbiotic relationship with root-nodulating bacteria of genera Rhizobium, Bradyrhizobium, or Sinorhizobium and colonization by arbuscular mycorrhizal fungi (AMF). Rhizobial symbiosis provides nitrogen necessary for growth. AMF symbiosis enhances uptake of diffusion-limited nutrients such as P, Zn, Cu, etc., and also water from the soil via plant-associated fungal hyphae. Rhizobial and AMF symbioses can act synergistically in promoting plant growth and fitness, resulting in overall yield benefits under drought stress. One of the approaches that rhizobia use to survive under stress is the accumulation of compatible solutes, or osmolytes, such as trehalose. Trehalose is a non-reducing disaccharide and an osmolyte reported to accumulate in a range of organisms. High accumulation of trehalose in bacteroids during nodulation protects cells and proteins from osmotic shock, desiccation, and heat under drought stress. Manipulation of trehalose cell concentrations has been directly correlated with stress response in plants and other organisms, including AMF. However, the role of this compound in the tripartite symbiotic relationship is not fully explored. This review describes the biological importance and the role of trehalose in the tripartite symbiosis between plants, rhizobia, and AMF. In particular, we review the physiological functions and the molecular investigations of trehalose carried out using omics-based approaches. This review will pave the way for future studies investigating possible metabolic engineering of this biomolecule for enhancing abiotic stress tolerance in plants.
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Affiliation(s)
- Mahaveer P. Sharma
- Microbiology Section, ICAR-Indian Institute of Soybean Research, Indore, India
| | - Minakshi Grover
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Dipanti Chourasiya
- Microbiology Section, ICAR-Indian Institute of Soybean Research, Indore, India
| | - Abhishek Bharti
- Microbiology Section, ICAR-Indian Institute of Soybean Research, Indore, India
| | - Richa Agnihotri
- Microbiology Section, ICAR-Indian Institute of Soybean Research, Indore, India
| | | | - Ashwani Pareek
- Stress Physiology and Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Jeffrey S. Buyer
- Sustainable Agricultural Systems Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center, Beltsville, MD, United States
| | - Sushil K. Sharma
- ICAR-National Institute of Biotic Stress Management, Raipur, India
| | - Lukas Schütz
- Department of Environmental Sciences-Botany, University of Basel, Basel, Switzerland
| | - Natarajan Mathimaran
- Department of Environmental Sciences-Botany, University of Basel, Basel, Switzerland
- M S Swaminathan Research Foundation, Chennai, India
| | - Sneh L. Singla-Pareek
- Plant Stress Biology, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Julie M. Grossman
- Department of Horticultural Science, College of Food, Agricultural and Natural Resource Sciences, University of Minnesota, St. Paul, MN, United States
| | - Davis J. Bagyaraj
- Center for Natural Biological Resources and Community Development, Bengaluru, India
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Onishchuk OP, Vorobyov NI, Provorov NA. Nodulation competitiveness of nodule bacteria: Genetic control and adaptive significance: Review. APPL BIOCHEM MICRO+ 2017. [DOI: 10.1134/s0003683817020132] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Piazza A, Zimaro T, Garavaglia BS, Ficarra FA, Thomas L, Marondedze C, Feil R, Lunn JE, Gehring C, Ottado J, Gottig N. The dual nature of trehalose in citrus canker disease: a virulence factor for Xanthomonas citri subsp. citri and a trigger for plant defence responses. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:2795-811. [PMID: 25770587 PMCID: PMC4986880 DOI: 10.1093/jxb/erv095] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Xanthomonas citri subsp. citri (Xcc) is a bacterial pathogen that causes citrus canker in susceptible Citrus spp. The Xcc genome contains genes encoding enzymes from three separate pathways of trehalose biosynthesis. Expression of genes encoding trehalose-6-phosphate synthase (otsA) and trehalose phosphatase (otsB) was highly induced during canker development, suggesting that the two-step pathway of trehalose biosynthesis via trehalose-6-phosphate has a function in pathogenesis. This pathway was eliminated from the bacterium by deletion of the otsA gene. The resulting XccΔotsA mutant produced less trehalose than the wild-type strain, was less resistant to salt and oxidative stresses, and was less able to colonize plant tissues. Gene expression and proteomic analyses of infected leaves showed that infection with XccΔotsA triggered only weak defence responses in the plant compared with infection with Xcc, and had less impact on the host plant's metabolism than the wild-type strain. These results suggested that trehalose of bacterial origin, synthesized via the otsA-otsB pathway, in Xcc, plays a role in modifying the host plant's metabolism to its own advantage but is also perceived by the plant as a sign of pathogen attack. Thus, trehalose biosynthesis has both positive and negative consequences for Xcc. On the one hand, it enables this bacterial pathogen to survive in the inhospitable environment of the leaf surface before infection and exploit the host plant's resources after infection, but on the other hand, it is a tell-tale sign of the pathogen's presence that triggers the plant to defend itself against infection.
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Affiliation(s)
- Ainelén Piazza
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda, Rosario 2000, Argentina
| | - Tamara Zimaro
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda, Rosario 2000, Argentina
| | - Betiana S Garavaglia
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda, Rosario 2000, Argentina
| | - Florencia A Ficarra
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda, Rosario 2000, Argentina
| | - Ludivine Thomas
- Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Claudius Marondedze
- Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Regina Feil
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam (OT) Golm, Germany
| | - John E Lunn
- Max Planck Institute of Molecular Plant Physiology, Wissenschaftspark Golm, Am Mühlenberg 1, 14476 Potsdam (OT) Golm, Germany
| | - Chris Gehring
- Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Jorgelina Ottado
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda, Rosario 2000, Argentina
| | - Natalia Gottig
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda, Rosario 2000, Argentina
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Baldacci-Cresp F, Maucourt M, Deborde C, Pierre O, Moing A, Brouquisse R, Favery B, Frendo P. Maturation of nematode-induced galls in Medicago truncatula is related to water status and primary metabolism modifications. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2015; 232:77-85. [PMID: 25617326 DOI: 10.1016/j.plantsci.2014.12.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 12/22/2014] [Accepted: 12/23/2014] [Indexed: 06/04/2023]
Abstract
Root-knot nematodes are obligatory plant parasitic worms that establish and maintain an intimate relationship with their host plants. During a compatible interaction, these nematodes induce the redifferentiation of root cells into multinucleate and hypertrophied giant cells (GCs). These metabolically active feeding cells constitute the exclusive source of nutrients for the nematode. We analyzed the modifications of water status, ionic content and accumulation of metabolites in development and mature galls induced by Meloidogyne incognita and in uninfected roots of Medicago truncatula plants. Water potential and osmotic pressure are significantly modified in mature galls compared to developing galls and control roots. Ionic content is significantly modified in galls compared to roots. Principal component analyses of metabolite content showed that mature gall metabolism is significantly modified compared to developing gall metabolism. The most striking differences were the three-fold increase of trehalose content associated to the five-fold diminution in glucose concentration in mature galls. Gene expression analysis showed that trehalose accumulation was, at least, partially linked to a significantly lower expression of the trehalase gene in mature galls. Our results point to significant modifications of gall physiology during maturation.
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Affiliation(s)
- Fabien Baldacci-Cresp
- Université de Nice Sophia-Antipolis, UMR Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France; INRA UMR 7254 Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France; CNRS UMR1355 Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France.
| | - Mickaël Maucourt
- Université de Bordeaux 2, UMR 1332 Biologie du Fruit et Pathologie, Centre INRA de Bordeaux, F-33140 Villenave d'Ornon, France; Metabolome Facility of Bordeaux Functional Genomics Center, IBVM, Centre INRA de Bordeaux, F-33140 Villenave d'Ornon, France
| | - Catherine Deborde
- Metabolome Facility of Bordeaux Functional Genomics Center, IBVM, Centre INRA de Bordeaux, F-33140 Villenave d'Ornon, France; INRA, UMR 1332 Biologie du Fruit et Pathologie, Centre INRA de Bordeaux, F-33140 Villenave d'Ornon, France
| | - Olivier Pierre
- Université de Nice Sophia-Antipolis, UMR Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France; INRA UMR 7254 Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France; CNRS UMR1355 Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France
| | - Annick Moing
- Metabolome Facility of Bordeaux Functional Genomics Center, IBVM, Centre INRA de Bordeaux, F-33140 Villenave d'Ornon, France; INRA, UMR 1332 Biologie du Fruit et Pathologie, Centre INRA de Bordeaux, F-33140 Villenave d'Ornon, France
| | - Renaud Brouquisse
- Université de Nice Sophia-Antipolis, UMR Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France; INRA UMR 7254 Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France; CNRS UMR1355 Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France
| | - Bruno Favery
- Université de Nice Sophia-Antipolis, UMR Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France; INRA UMR 7254 Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France; CNRS UMR1355 Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France
| | - Pierre Frendo
- Université de Nice Sophia-Antipolis, UMR Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France; INRA UMR 7254 Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France; CNRS UMR1355 Institut Sophia Agrobiotech, 400 route des chappes BP167, F-06903 Sophia Antipolis, France
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Ampomah OY, Jensen JB. The trehalose utilization gene thuA ortholog in Mesorhizobium loti does not influence competitiveness for nodulation on Lotus spp. World J Microbiol Biotechnol 2014; 30:1129-34. [DOI: 10.1007/s11274-013-1527-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 10/14/2013] [Indexed: 11/30/2022]
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The thuEFGKAB operon of rhizobia and agrobacterium tumefaciens codes for transport of trehalose, maltitol, and isomers of sucrose and their assimilation through the formation of their 3-keto derivatives. J Bacteriol 2013; 195:3797-807. [PMID: 23772075 DOI: 10.1128/jb.00478-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The thu operon (thuEFGKAB) in Sinorhizobium meliloti codes for transport and utilization functions of the disaccharide trehalose. Sequenced genomes of members of the Rhizobiaceae reveal that some rhizobia and Agrobacterium possess the entire thu operon in similar organizations and that Mesorhizobium loti MAFF303099 lacks the transport (thuEFGK) genes. In this study, we show that this operon is dedicated to the transport and assimilation of maltitol and isomers of sucrose (leucrose, palatinose, and trehalulose) in addition to trehalulose, not only in S. meliloti but also in Agrobacterium tumefaciens. By using genetic complementation, we show that the thuAB genes of S. meliloti, M. loti, and A. tumefaciens are functionally equivalent. Further, we provide both genetic and biochemical evidence to show that these bacteria assimilate these disaccharides by converting them to their respective 3-keto derivatives and that the thuAB genes code for this ketodisaccharide-forming enzyme(s). Formation of 3-ketotrehalose in real time in live S. meliloti is shown through Raman spectroscopy. The presence of an additional ketodisaccharide-forming pathway(s) in A. tumefaciens is also indicated. To our knowledge, this is the first report to identify the genes that code for the conversion of disaccharides to their 3-ketodisaccharide derivatives in any organism.
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Barraza A, Estrada-Navarrete G, Rodriguez-Alegria ME, Lopez-Munguia A, Merino E, Quinto C, Sanchez F. Down-regulation of PvTRE1 enhances nodule biomass and bacteroid number in the common bean. THE NEW PHYTOLOGIST 2013; 197:194-206. [PMID: 23121215 DOI: 10.1111/nph.12002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 09/12/2012] [Indexed: 05/02/2023]
Abstract
Legume-rhizobium interactions have been widely studied and characterized, and the disaccharide trehalose has been commonly detected during this symbiotic interaction. It has been proposed that trehalose content in nodules during this symbiotic interaction might be regulated by trehalase. In the present study, we assessed the role of trehalose accumulation by down-regulating trehalase in the nodules of common bean plants. We performed gene expression analysis for trehalase (PvTRE1) during nodule development. PvTRE1 was knocked down by RNA interference (RNAi) in transgenic nodules of the common bean. PvTRE1 expression in nodulated roots is mainly restricted to nodules. Down-regulation of PvTRE1 led to increased trehalose content (78%) and bacteroid number (almost one order of magnitude). In addition, nodule biomass, nitrogenase activity, and GOGAT transcript accumulation were significantly enhanced too. The trehalose accumulation, triggered by PvTRE1 down-regulation, led to a positive impact on the legume-rhizobium symbiotic interaction. This could contribute to the agronomical enhancement of symbiotic nitrogen fixation.
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MESH Headings
- Agrobacterium/genetics
- Agrobacterium/metabolism
- Autophagy
- Bacterial Load
- Carbohydrate Metabolism
- Cloning, Molecular
- Escherichia coli/enzymology
- Escherichia coli/genetics
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Gene Knockdown Techniques
- Genes, Plant
- Microbial Viability
- Nitrogen Fixation
- Nitrogenase/genetics
- Nitrogenase/metabolism
- Phaseolus/enzymology
- Phaseolus/genetics
- Phaseolus/microbiology
- Phylogeny
- Plant Leaves/enzymology
- Plant Leaves/genetics
- Plant Root Nodulation
- Plants, Genetically Modified/enzymology
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/microbiology
- Promoter Regions, Genetic
- RNA Interference
- Rhizobium etli/growth & development
- Rhizobium etli/isolation & purification
- Rhizobium etli/metabolism
- Root Nodules, Plant/enzymology
- Root Nodules, Plant/microbiology
- Symbiosis
- Transformation, Genetic
- Trehalase/genetics
- Trehalase/metabolism
- Trehalose/metabolism
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Affiliation(s)
- Aarón Barraza
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología/Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos, 62210, México
| | - Georgina Estrada-Navarrete
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología/Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos, 62210, México
| | - Maria Elena Rodriguez-Alegria
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología/Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos, 62210, México
| | - Agustin Lopez-Munguia
- Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología/Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos, 62210, México
| | - Enrique Merino
- Departamento de Microbiología Molecular, Instituto de Biotecnología/Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos, 62210, México
| | - Carmen Quinto
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología/Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos, 62210, México
| | - Federico Sanchez
- Departamento de Biología Molecular de Plantas, Instituto de Biotecnología/Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos, 62210, México
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Abstract
Although 'cheaters' potentially destabilize the legume-rhizobium mutualism, we lack a comprehensive review of host-symbiont fitness correlations. Studies measuring rhizobium relative or absolute fitness and host benefit are surveyed. Mutant studies are tallied for evidence of pleiotropy; studies of natural strains are analyzed with meta-analysis. Of 80 rhizobium mutations, 19 decrease both partners' fitness, four increase both, two increase host fitness but decrease symbiont fitness and none increase symbiont fitness at the host's expense. The pooled correlation between rhizobium nodulation competitiveness and plant aboveground biomass is 0.65 across five experiments that compete natural strains against a reference, whereas, across 14 experiments that compete rhizobia against soil populations or each other, the pooled correlation is 0.24. Pooled correlations between aboveground biomass and nodule number and nodule biomass are 0.76 and 0.83. Positive correlations between legume and rhizobium fitness imply that most ineffective rhizobia are 'defective' rather than 'defectors'; this extends to natural variants, with only one significant fitness conflict. Most studies involve non-coevolved associations, indicating that fitness alignment is the default state. Rhizobium mutations that increase both host and symbiont fitness suggest that some plants maladaptively restrict symbiosis with novel strains.
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Affiliation(s)
- Maren L Friesen
- Center for Population Biology, University of California, Davis, One Shields Ave., Davis, CA 95616, USA
- Present address: Section of Molecular and Computational Biology, Department of Biology, University of Southern California, 1050 Childs Way, RRI 201-B Los Angeles, CA 90089, USA
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10
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Brechenmacher L, Lei Z, Libault M, Findley S, Sugawara M, Sadowsky MJ, Sumner LW, Stacey G. Soybean metabolites regulated in root hairs in response to the symbiotic bacterium Bradyrhizobium japonicum. PLANT PHYSIOLOGY 2010; 153:1808-22. [PMID: 20534735 PMCID: PMC2923908 DOI: 10.1104/pp.110.157800] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 06/08/2010] [Indexed: 05/18/2023]
Abstract
Nodulation of soybean (Glycine max) root hairs by the nitrogen-fixing symbiotic bacterium Bradyrhizobium japonicum is a complex process coordinated by the mutual exchange of diffusible signal molecules. A metabolomic study was performed to identify small molecules produced in roots and root hairs during the rhizobial infection process. Metabolites extracted from roots and root hairs mock inoculated or inoculated with B. japonicum were analyzed by gas chromatography-mass spectrometry and ultraperformance liquid chromatography-quadrupole time of flight-mass spectrometry. These combined approaches identified 2,610 metabolites in root hairs. Of these, 166 were significantly regulated in response to B. japonicum inoculation, including various (iso)flavonoids, amino acids, fatty acids, carboxylic acids, and various carbohydrates. Trehalose was among the most strongly induced metabolites produced following inoculation. Subsequent metabolomic analyses of root hairs inoculated with a B. japonicum mutant defective in the trehalose synthase, trehalose 6-phosphate synthase, and maltooligosyltrehalose synthase genes showed that the trehalose detected in the inoculated root hairs was primarily of bacterial origin. Since trehalose is generally considered an osmoprotectant, these data suggest that B. japonicum likely experiences osmotic stress during the infection process, either on the root hair surface or within the infection thread.
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Affiliation(s)
| | | | | | | | | | | | | | - Gary Stacey
- National Center for Soybean Biotechnology, Division of Plant Sciences (L.B., M.L., S.F., G.S.), and Center for Sustainable Energy, Division of Biochemistry (G.S.), University of Missouri, Columbia, Missouri 65211; Plant Biology Division, The Samuel Roberts Noble Foundation, Ardmore, Oklahoma 73401 (Z.L., L.W.S.); Department of Soil, Water, and Climate (M.S., M.J.S.) and Microbial and Plant Genomics Institute, BioTechnology Institute (M.J.S.), University of Minnesota, St. Paul, Minnesota 55108
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Fernandez O, Béthencourt L, Quero A, Sangwan RS, Clément C. Trehalose and plant stress responses: friend or foe? TRENDS IN PLANT SCIENCE 2010; 15:409-17. [PMID: 20494608 DOI: 10.1016/j.tplants.2010.04.004] [Citation(s) in RCA: 205] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 04/06/2010] [Accepted: 04/22/2010] [Indexed: 05/18/2023]
Abstract
The disaccharide trehalose is involved in stress response in many organisms. However, in plants, its precise role remains unclear, although some data indicate that trehalose has a protective role during abiotic stresses. By contrast, some trehalose metabolism mutants exhibit growth aberrations, revealing potential negative effects on plant physiology. Contradictory effects also appear under biotic stress conditions. Specifically, trehalose is essential for the infectivity of several pathogens but at the same time elicits plant defense. Here, we argue that trehalose should not be regarded only as a protective sugar but rather like a double-faced molecule and that further investigation is required to elucidate its exact role in stress tolerance in plants.
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Affiliation(s)
- Olivier Fernandez
- Université de Reims Champagne Ardenne, Unité de Recherche Vignes et Vins de Champagne - Stress et Environnement (EA 2069), UFR Sciences Exactes et Naturelles, BP 1039, 51687 Reims Cedex 2, France
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Sugawara M, Cytryn EJ, Sadowsky MJ. Functional role of Bradyrhizobium japonicum trehalose biosynthesis and metabolism genes during physiological stress and nodulation. Appl Environ Microbiol 2010; 76:1071-81. [PMID: 20023090 PMCID: PMC2820964 DOI: 10.1128/aem.02483-09] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Accepted: 12/10/2009] [Indexed: 11/20/2022] Open
Abstract
Trehalose, a disaccharide accumulated by many microorganisms, acts as a protectant during periods of physiological stress, such as salinity and desiccation. Previous studies reported that the trehalose biosynthetic genes (otsA, treS, and treY) in Bradyrhizobium japonicum were induced by salinity and desiccation stresses. Functional mutational analyses indicated that disruption of otsA decreased trehalose accumulation in cells and that an otsA treY double mutant accumulated an extremely low level of trehalose. In contrast, trehalose accumulated to a greater extent in a treS mutant, and maltose levels decreased relative to that seen with the wild-type strain. Mutant strains lacking the OtsA pathway, including the single, double, and triple DeltaotsA, DeltaotsA DeltatreS and DeltaotsA DeltatreY, and DeltaotsA DeltatreS DeltatreY mutants, were inhibited for growth on 60 mM NaCl. While mutants lacking functional OtsAB and TreYZ pathways failed to grow on complex medium containing 60 mM NaCl, there was no difference in the viability of the double mutant strain when cells were grown under conditions of desiccation stress. In contrast, mutants lacking a functional TreS pathway were less tolerant of desiccation stress than the wild-type strain. Soybean plants inoculated with mutants lacking the OtsAB and TreYZ pathways produced fewer mature nodules and a greater number of immature nodules relative to those produced by the wild-type strain. Taken together, results of these studies indicate that stress-induced trehalose biosynthesis in B. japonicum is due mainly to the OtsAB pathway and that the TreS pathway is likely involved in the degradation of trehalose to maltose. Trehalose accumulation in B. japonicum enhances survival under conditions of salinity stress and plays a role in the development of symbiotic nitrogen-fixing root nodules on soybean plants.
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Affiliation(s)
- Masayuki Sugawara
- Department of Soil, Water, and Climate, Microbial and Plant Genomics Institute, BioTechnology Institute, University of Minnesota, St. Paul, Minnesota 55108
| | - Eddie J. Cytryn
- Department of Soil, Water, and Climate, Microbial and Plant Genomics Institute, BioTechnology Institute, University of Minnesota, St. Paul, Minnesota 55108
| | - Michael J. Sadowsky
- Department of Soil, Water, and Climate, Microbial and Plant Genomics Institute, BioTechnology Institute, University of Minnesota, St. Paul, Minnesota 55108
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