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Berrabah F, Benaceur F, Yin C, Xin D, Magne K, Garmier M, Gruber V, Ratet P. Defense and senescence interplay in legume nodules. PLANT COMMUNICATIONS 2024; 5:100888. [PMID: 38532645 PMCID: PMC11009364 DOI: 10.1016/j.xplc.2024.100888] [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: 10/03/2023] [Revised: 02/05/2024] [Accepted: 03/23/2024] [Indexed: 03/28/2024]
Abstract
Immunity and senescence play a crucial role in the functioning of the legume symbiotic nodules. The miss-regulation of one of these processes compromises the symbiosis leading to death of the endosymbiont and the arrest of the nodule functioning. The relationship between immunity and senescence has been extensively studied in plant organs where a synergistic response can be observed. However, the interplay between immunity and senescence in the symbiotic organ is poorly discussed in the literature and these phenomena are often mixed up. Recent studies revealed that the cooperation between immunity and senescence is not always observed in the nodule, suggesting complex interactions between these two processes within the symbiotic organ. Here, we discuss recent results on the interplay between immunity and senescence in the nodule and the specificities of this relationship during legume-rhizobium symbiosis.
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Affiliation(s)
- Fathi Berrabah
- Faculty of Sciences, University Amar Telidji, 03000 Laghouat, Algeria; Research Unit of Medicinal Plants (RUMP), National Center of Biotechnology Research, CRBt, 25000 Constantine, Algeria.
| | - Farouk Benaceur
- Faculty of Sciences, University Amar Telidji, 03000 Laghouat, Algeria; Research Unit of Medicinal Plants (RUMP), National Center of Biotechnology Research, CRBt, 25000 Constantine, Algeria
| | - Chaoyan Yin
- Université Paris-Saclay, CNRS, INRAE, University of Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France; Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
| | - Dawei Xin
- Key Laboratory of Soybean Biology in the Chinese Ministry of Education, College of Agriculture, Northeast Agricultural University, Harbin 150030, China
| | - Kévin Magne
- Université Paris-Saclay, CNRS, INRAE, University of Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France; Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
| | - Marie Garmier
- Université Paris-Saclay, CNRS, INRAE, University of Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France; Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
| | - Véronique Gruber
- Université Paris-Saclay, CNRS, INRAE, University of Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France; Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France.
| | - Pascal Ratet
- Université Paris-Saclay, CNRS, INRAE, University of Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France; Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
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2
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Ke X, Xiao H, Peng Y, Xia X, Wang X. Nitrogen deficiency modulates carbon allocation to promote nodule nitrogen fixation capacity in soybean. EXPLORATION (BEIJING, CHINA) 2024; 4:20230104. [PMID: 38855619 PMCID: PMC11022614 DOI: 10.1002/exp.20230104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 11/02/2023] [Indexed: 06/11/2024]
Abstract
Previously, the effect of soil mineral N deficiency on nodule nitrogen fixation capacity (NFC) is unclear. In this study, we found that N deficiency would enhance sucrose allocation to nodules and PEP allocation to bacteroid to promote nodule NFC. Our findings provide new insights into the design of leguminous crops with improved adaptation to fluctuating N levels in the soil.
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Affiliation(s)
- Xiaolong Ke
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life SciencesHenan UniversityZhengzhouChina
- The Academy for Advanced Interdisciplinary StudiesHenan UniversityZhengzhouHenanChina
- Sanya Institute of Henan UniversitySanyaHainanChina
| | - Han Xiao
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life SciencesHenan UniversityZhengzhouChina
- The Academy for Advanced Interdisciplinary StudiesHenan UniversityZhengzhouHenanChina
- Sanya Institute of Henan UniversitySanyaHainanChina
| | - Yaqi Peng
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life SciencesHenan UniversityZhengzhouChina
- The Academy for Advanced Interdisciplinary StudiesHenan UniversityZhengzhouHenanChina
- Sanya Institute of Henan UniversitySanyaHainanChina
| | - Xue Xia
- School of Environmental and Life Sciences, College of Engineering, Science and EnvironmentUniversity of NewcastleCallaghanNew South WalesAustralia
| | - Xuelu Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life SciencesHenan UniversityZhengzhouChina
- The Academy for Advanced Interdisciplinary StudiesHenan UniversityZhengzhouHenanChina
- Sanya Institute of Henan UniversitySanyaHainanChina
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3
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Sulieman S, Sheteiwy MS, Abdelrahman M, Tran LSP. γ-Aminobutyric acid (GABA) in N 2-fixing-legume symbiosis: Metabolic flux and carbon/nitrogen homeostasis in responses to abiotic constraints. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 207:108362. [PMID: 38266561 DOI: 10.1016/j.plaphy.2024.108362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 12/07/2023] [Accepted: 01/10/2024] [Indexed: 01/26/2024]
Abstract
Nodule symbiosis is an energetic process that demands a tremendous carbon (C) cost, which massively increases in responses to environmental stresses. Notably, most common respiratory pathways (e.g., glycolysis and Krebs cycle) that sustain nitrogenase activity and subsequent nitrogen (N) assimilation (amino acid formation) display a noncyclic mode of C flux. In such circumstances, the nodule's energy charge could markedly decrease, leading to a lower symbiotic activity under stresses. The host plant then attempts to induce alternative robust metabolic pathways to minimize the C expenditure and compensate for the loss in respiratory substrates. GABA (γ-aminobutyric acid) shunt appears to be among the highly conserved metabolic bypass induced in responses to stresses. Thus, it can be suggested that GABA, via its primary biosynthetic pathway (GABA shunt), is simultaneously induced to circumvent stress-susceptible decarboxylating portion of the Krebs cycle and to replenish symbiosome with energy and C skeletons for enhancing nitrogenase activity and N assimilation besides the additional C costs expended in the metabolic stress acclimations (e.g., biosynthesis of secondary metabolites and excretion of anions). The GABA-mediated C/N balance is strongly associated with interrelated processes, including pH regulation, oxygen (O2) protection, osmoregulation, cellular redox control, and N storage. Furthermore, it has been anticipated that GABA could be implicated in other functions beyond its metabolic role (i.e., signaling and transport). GABA helps plants possess remarkable metabolic plasticity, which might thus assist nodules in attenuating stressful events.
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Affiliation(s)
- Saad Sulieman
- Department of Agronomy, Faculty of Agriculture, University of Khartoum, 13314, Shambat, Khartoum North, Sudan.
| | - Mohamed S Sheteiwy
- Department of Integrative Agriculture, College of Agriculture and Veterinary Medicine, United Arab Emirates University, P.O. Box 15551, Al Ain, Abu Dhabi, United Arab Emirates; Department of Agronomy, Faculty of Agriculture, Mansoura University, Mansoura, 35516, Egypt
| | - Mostafa Abdelrahman
- Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, TX, 79409, USA
| | - Lam-Son Phan Tran
- Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, TX, 79409, USA.
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4
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Martin ML, Pervent M, Lambert I, Colella S, Tancelin M, Severac D, Clément G, Tillard P, Frugier F, Lepetit M. Localized osmotic stress activates systemic responses to N limitation in Medicago truncatula-Sinorhizobium symbiotic plants. FRONTIERS IN PLANT SCIENCE 2023; 14:1288070. [PMID: 38053772 PMCID: PMC10694431 DOI: 10.3389/fpls.2023.1288070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Accepted: 10/24/2023] [Indexed: 12/07/2023]
Abstract
In mature symbiotic root nodules, differentiated rhizobia fix atmospheric dinitrogen and provide ammonium to fulfill the plant nitrogen (N) demand. The plant enables this process by providing photosynthates to the nodules. The symbiosis is adjusted to the whole plant N demand thanks to systemic N signaling controlling nodule development. Symbiotic plants under N deficit stimulate nodule expansion and activate nodule senescence under N satiety. Besides, nodules are highly sensitive to drought. Here, we used split-root systems to characterize the systemic responses of symbiotic plants to a localized osmotic stress. We showed that polyéthylène glycol (PEG) application rapidly inhibited the symbiotic dinitrogen fixation activity of nodules locally exposed to the treatment, resulting to the N limitation of the plant supplied exclusively by symbiotic dinitrogen fixation. The localized PEG treatment triggered systemic signaling stimulating nodule development in the distant untreated roots. This response was associated with an enhancement of the sucrose allocation. Our analyses showed that transcriptomic reprogramming associated with PEG and N deficit systemic signaling(s) shared many targets transcripts. Altogether, our study suggests that systemic N signaling is a component of the adaptation of the symbiotic plant to the local variations of its edaphic environment.
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Affiliation(s)
- Marie-Laure Martin
- Université Paris-Saclay, CNRS, INRAE, Univ d’Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Gif sur Yvette, France
- Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), Gif sur Yvette, France
- Université Paris-Saclay, AgroParisTech, INRAE, UMR MIA, Paris-Saclay, Palaiseau, France
| | - Marjorie Pervent
- LSTM, Laboratoire des Symbioses Tropicales et Méditerranéennes, INRAE, IRD, CIRAD, Institut Agro Montpellier, Université de Montpellier, Montpellier, France
- PHIM Plant Health Institute, INRAE, Université de Montpellier, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Ilana Lambert
- LSTM, Laboratoire des Symbioses Tropicales et Méditerranéennes, INRAE, IRD, CIRAD, Institut Agro Montpellier, Université de Montpellier, Montpellier, France
| | - Stefano Colella
- LSTM, Laboratoire des Symbioses Tropicales et Méditerranéennes, INRAE, IRD, CIRAD, Institut Agro Montpellier, Université de Montpellier, Montpellier, France
- PHIM Plant Health Institute, INRAE, Université de Montpellier, CIRAD, Institut Agro, IRD, Montpellier, France
| | - Mathilde Tancelin
- LSTM, Laboratoire des Symbioses Tropicales et Méditerranéennes, INRAE, IRD, CIRAD, Institut Agro Montpellier, Université de Montpellier, Montpellier, France
| | - Dany Severac
- MGX, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Gilles Clément
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, CNRS, Université Paris-Saclay, Versailles, France
| | - Pascal Tillard
- Biologie et Physiologie Moléculaire des Plantes, INRAE, CNRS, Institut Agro Montpellier, Université de Montpellier, Montpellier, France
| | - Florian Frugier
- Université Paris-Saclay, CNRS, INRAE, Univ d’Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Gif sur Yvette, France
- Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), Gif sur Yvette, France
| | - Marc Lepetit
- LSTM, Laboratoire des Symbioses Tropicales et Méditerranéennes, INRAE, IRD, CIRAD, Institut Agro Montpellier, Université de Montpellier, Montpellier, France
- Institut Sophia Agrobiotech, INRAE, CNRS, Université Côte d'Azur, Sophia-Antipolis, France
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Amoako FK, Sulieman S, Mühling KH. Mineral and Carbon Metabolic Adjustments in Nodules of Symbiotically Grown Faba Bean ( Vicia faba L.) Varieties in Response to Organic Phosphorus Supplementation. PLANTS (BASEL, SWITZERLAND) 2023; 12:3888. [PMID: 38005785 PMCID: PMC10675292 DOI: 10.3390/plants12223888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 11/02/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023]
Abstract
Phosphorus (P) is a major limiting factor for legume and symbiotic nitrogen fixation (SNF). Although overall adaptations of legumes to P supplementation have been extensively studied in connection with inorganic P, little information is currently available regarding nodulation or SNF responses to organic P (Po) in hydroponics. We investigated the mineral and carbon metabolism of Po-induced nodules of two contrasting faba bean varieties grown hydroponically under inorganic P (Pi), viz., in P-deficient (2 µM KH2PO4, -Pi), sufficient-P (200 µM KH2PO4, +Pi), and phytic acid (200 µM, Po) conditions, and were inoculated with Rhizobium leguminosarum bv. viciae 3841 and grown for 30 days. The results consistently reveal similar growth and biomass partitioning patterns between +Pi and Po, with both varying substantially from -Pi. In comparison, +Pi and Po observed equivalent accumulations of overall elemental P concentrations, with both increasing by 114 and 119%, respectively, relative to -Pi. A principal component analysis on metabolites showed a clear separation of the -Pi treatment from the others, with +Pi and Po correlating closely together, highlighting the nonsignificant differences between them. Additionally, the δ15N abundance of shoots, roots, and nodules was not significantly different between treatments and varieties and exhibited negative δ15N signatures for all tissues. Our study provides a novel perspective on mineral and carbon metabolism and their regulation of the growth, functioning, and reprogramming of nodules upon phytate supply.
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Affiliation(s)
| | | | - Karl H. Mühling
- Institute of Plant Nutrition and Soil Science, Kiel University, Hermann-Rodewald-Straße 2, 24118 Kiel, Germany; (F.K.A.); (S.S.)
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6
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Lepetit M, Brouquisse R. New insights into the control of symbiotic nitrogen fixation by carbon supply. MOLECULAR PLANT 2023; 16:1724-1726. [PMID: 37794681 DOI: 10.1016/j.molp.2023.09.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/06/2023]
Affiliation(s)
- Marc Lepetit
- Institut Sophia Agrobiotech, INRAE, Université Côte d'Azur, CNRS, 06903 Sophia-Antipolis, France.
| | - Renaud Brouquisse
- Institut Sophia Agrobiotech, INRAE, Université Côte d'Azur, CNRS, 06903 Sophia-Antipolis, France
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Zhang H. Plant latent defense response against compatibility. THE ISME JOURNAL 2023; 17:787-791. [PMID: 36991179 PMCID: PMC10203107 DOI: 10.1038/s41396-023-01399-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 03/14/2023] [Accepted: 03/17/2023] [Indexed: 03/31/2023]
Abstract
Managing the association with microbes is crucial for plants. Evidence is emerging for the plant latent defense response, which is conditionally elicited by certain microbial nonpathogenic factors and thereby guards against potential risks from beneficial or commensal microbes. Latent defense response is an exciting new research area with a number of key issues immediately awaiting exploration. A detailed understanding of latent defense response will underpin the applications of beneficial microbes.
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Affiliation(s)
- Huiming Zhang
- Shanghai Center for Plant Stress Biology, Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, 201602, China.
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8
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Lepetit M, Brouquisse R. Control of the rhizobium-legume symbiosis by the plant nitrogen demand is tightly integrated at the whole plant level and requires inter-organ systemic signaling. FRONTIERS IN PLANT SCIENCE 2023; 14:1114840. [PMID: 36968361 PMCID: PMC10033964 DOI: 10.3389/fpls.2023.1114840] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 02/16/2023] [Indexed: 06/18/2023]
Abstract
Symbiotic nodules formed on legume roots with rhizobia fix atmospheric N2. Bacteria reduce N2 to NH4 + that is assimilated into amino acids by the plant. In return, the plant provides photosynthates to fuel the symbiotic nitrogen fixation. Symbiosis is tightly adjusted to the whole plant nutritional demand and to the plant photosynthetic capacities, but regulatory circuits behind this control remain poorly understood. The use of split-root systems combined with biochemical, physiological, metabolomic, transcriptomic, and genetic approaches revealed that multiple pathways are acting in parallel. Systemic signaling mechanisms of the plant N demand are required for the control of nodule organogenesis, mature nodule functioning, and nodule senescence. N-satiety/N-deficit systemic signaling correlates with rapid variations of the nodules' sugar levels, tuning symbiosis by C resources allocation. These mechanisms are responsible for the adjustment of plant symbiotic capacities to the mineral N resources. On the one hand, if mineral N can satisfy the plant N demand, nodule formation is inhibited, and nodule senescence is activated. On the other hand, local conditions (abiotic stresses) may impair symbiotic activity resulting in plant N limitation. In these conditions, systemic signaling may compensate the N deficit by stimulating symbiotic root N foraging. In the past decade, several molecular components of the systemic signaling pathways controlling nodule formation have been identified, but a major challenge remains, that is, to understand their specificity as compared to the mechanisms of non-symbiotic plants that control root development and how they contribute to the whole plant phenotypes. Less is known about the control of mature nodule development and functioning by N and C nutritional status of the plant, but a hypothetical model involving the sucrose allocation to the nodule as a systemic signaling process, the oxidative pentose phosphate pathway, and the redox status as potential effectors of this signaling is emerging. This work highlights the importance of organism integration in plant biology.
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9
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Luo L, Cao X. Nodule-specific energy sensors determine symbiotic nitrogen fixation by regulating phosphoenolpyruvate allocation. SCIENCE CHINA. LIFE SCIENCES 2023; 66:643-645. [PMID: 36515862 DOI: 10.1007/s11427-022-2256-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 12/04/2022] [Indexed: 12/15/2022]
Affiliation(s)
- Lilan Luo
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiaofeng Cao
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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Tixier A, Forest M, Prudent M, Durey V, Zwieniecki M, Barnard RL. Root exudation of carbon and nitrogen compounds varies over the day-night cycle in pea: The role of diurnal changes in internal pools. PLANT, CELL & ENVIRONMENT 2023; 46:962-974. [PMID: 36562125 DOI: 10.1111/pce.14523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 12/13/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
Rhizodeposition is the export of organic compounds from plant roots to the soil. Carbon allocation towards rhizodeposition has to be balanced with allocation for other physiological functions, which depend on both newly assimilated and stored nonstructural carbohydrate (NSC). To test whether the exudation of primary metabolites scales with plant NSC status, we studied diurnal dynamics of NSC and amino acid (AA) pools and fluxes within the plant and the rhizosphere. These diurnal dynamics were measured in the field and under hydroponic-controlled conditions. Further, C-limiting treatments offered further insight into the regulation of rhizodeposition. The exudation of primary metabolites fluctuated diurnally. The diurnal dynamics of soluble sugars (SS) and AA concentrations in tissues coincided with exudate pool fluctuations in the rhizosphere. SS and AA pools in the rhizosphere increased with NSC and AA pools in the roots. C starvation treatments offset the balance of exudates: AA exudate content in the rhizosphere significantly decreased while SS exudate content remained stable. Our results suggest that rhizodeposition is to some extent controlled by plant C:N status. We propose that SS exudation is less controlled than AA exudation because N assimilation depends on controlled C supply while SS exudation relies to a greater extent on passive diffusion mechanisms.
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Affiliation(s)
- Aude Tixier
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université Bourgogne Franche-Comté, Dijon, France
| | - Marion Forest
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université Bourgogne Franche-Comté, Dijon, France
| | - Marion Prudent
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université Bourgogne Franche-Comté, Dijon, France
| | - Vincent Durey
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université Bourgogne Franche-Comté, Dijon, France
| | - Maciej Zwieniecki
- Department of Plant Sciences, University of California, Davis, California, USA
| | - Romain L Barnard
- Agroécologie, AgroSup Dijon, INRAE, Université de Bourgogne, Université Bourgogne Franche-Comté, Dijon, France
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11
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Li S, Wu C, Liu H, Lyu X, Xiao F, Zhao S, Ma C, Yan C, Liu Z, Li H, Wang X, Gong Z. Systemic regulation of nodule structure and assimilated carbon distribution by nitrate in soybean. FRONTIERS IN PLANT SCIENCE 2023; 14:1101074. [PMID: 36814755 PMCID: PMC9939697 DOI: 10.3389/fpls.2023.1101074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/13/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND The nitrate regulates soybean nodulation and nitrogen fixation systemically, mainly in inhibiting nodule growth and reducing nodule nitrogenase activity, but the reason for its inhibition is still inconclusive. METHODS The systemic effect of nitrate on nodule structure, function, and carbon distribution in soybean (Glycine max (L.) Merr.) was studied in a dual-root growth system, with both sides inoculated with rhizobia and only one side subjected to nitrate treatment for four days. The non-nodulating side was genetically devoid of the ability to form nodules. Nutrient solutions with nitrogen concentrations of 0, 100, and 200 mg L-1 were applied as KNO3 to the non-nodulating side, while the nodulating side received a nitrogen-free nutrient solution. Carbon partitioning in roots and nodules was monitored using 13C-labelled CO2. Other nodule responses were measured via the estimation of the nitrogenase activity and the microscopic observation of nodule ultrastructure. RESULTS Elevated concentrations of nitrate applied on the non-nodulating side caused a decrease in the number of bacteroids, fusion of symbiosomes, enlargement of the peribacteroid spaces, and onset of degradation of poly-β-hydroxybutyrate granules, which is a form of carbon storage in bacteroids. These microscopic observations were associated with a strong decrease in the nitrogenase activity of nodules. Furthermore, our data demonstrate that the assimilated carbon is more likely to be allocated to the non-nodulating roots, as follows from the competition for carbon between the symbiotic and non-symbiotic sides of the dual-root system. CONCLUSION We propose that there is no carbon competition between roots and nodules when they are indirectly supplied with nitrate, and that the reduction of carbon fluxes to nodules and roots on the nodulating side is the mechanism by which the plant systemically suppresses nodulation under nitrogen-replete conditions.
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Affiliation(s)
- Sha Li
- College of Resources and Environment, Northeast Agricultural University, Harbin, China
| | - Chengbin Wu
- College of Resources and Environment, Northeast Agricultural University, Harbin, China
| | - Hao Liu
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Xiaochen Lyu
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Fengsheng Xiao
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Shuhong Zhao
- College of Engineering, Northeast Agricultural University, Harbin, China
| | - Chunmei Ma
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Chao Yan
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Zhilei Liu
- College of Resources and Environment, Northeast Agricultural University, Harbin, China
| | - Hongyu Li
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Xuelai Wang
- College of Agriculture, Northeast Agricultural University, Harbin, China
| | - Zhenping Gong
- College of Agriculture, Northeast Agricultural University, Harbin, China
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12
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Berrabah F, Bernal G, Elhosseyn AS, El Kassis C, L’Horset R, Benaceur F, Wen J, Mysore KS, Garmier M, Gourion B, Ratet P, Gruber V. Insight into the control of nodule immunity and senescence during Medicago truncatula symbiosis. PLANT PHYSIOLOGY 2023; 191:729-746. [PMID: 36305683 PMCID: PMC9806560 DOI: 10.1093/plphys/kiac505] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 09/25/2022] [Indexed: 06/16/2023]
Abstract
Medicago (Medicago truncatula) establishes a symbiosis with the rhizobia Sinorhizobium sp, resulting in the formation of nodules where the bacteria fix atmospheric nitrogen. The loss of immunity repression or early senescence activation compromises symbiont survival and leads to the formation of nonfunctional nodules (fix-). Despite many studies exploring an overlap between immunity and senescence responses outside the nodule context, the relationship between these processes in the nodule remains poorly understood. To investigate this phenomenon, we selected and characterized three Medicago mutants developing fix- nodules and showing senescence responses. Analysis of specific defense (PATHOGENESIS-RELATED PROTEIN) or senescence (CYSTEINE PROTEASE) marker expression demonstrated that senescence and immunity seem to be antagonistic in fix- nodules. The growth of senescence mutants on non-sterile (sand/perlite) substrate instead of sterile in vitro conditions decreased nodule senescence and enhanced defense, indicating that environment can affect the immunity/senescence balance. The application of wounding stress on wild-type (WT) fix+ nodules led to the death of intracellular rhizobia and associated with co-stimulation of defense and senescence markers, indicating that in fix+ nodules the relationship between the two processes switches from opposite to synergistic to control symbiont survival during response to the stress. Our data show that the immune response in stressed WT nodules is linked to the repression of DEFECTIVE IN NITROGEN FIXATION 2 (DNF2), Symbiotic CYSTEINE-RICH RECEPTOR-LIKE KINASE (SymCRK), and REGULATOR OF SYMBIOSOME DIFFERENTIATION (RSD), key genes involved in symbiotic immunity suppression. This study provides insight to understand the links between senescence and immunity in Medicago nodules.
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Affiliation(s)
- Fathi Berrabah
- Faculty of Sciences, Department of Biology, Amar Telidji University, 03000 Laghouat, Algeria
- Research Unit of Medicinal Plants (RUMP), National Center of Biotechnology Research, CRBt, 25000 Constantine, Algeria
| | - Gautier Bernal
- Université Paris-Saclay, CNRS, INRAE, Université d’Évry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
- Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
| | - Ait-Salem Elhosseyn
- Université Paris-Saclay, CNRS, INRAE, Université d’Évry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
- Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
| | - Cyrille El Kassis
- Université Paris-Saclay, CNRS, INRAE, Université d’Évry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
- Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
| | - Roxane L’Horset
- Pôle de Protection des Plantes, UMR PVBMT, 97410 Saint-Pierre, Réunion, France
| | - Farouk Benaceur
- Faculty of Sciences, Department of Biology, Amar Telidji University, 03000 Laghouat, Algeria
- Research Unit of Medicinal Plants (RUMP), National Center of Biotechnology Research, CRBt, 25000 Constantine, Algeria
| | - Jiangqi Wen
- The Institute of Agricultural Biosciences, Oklahoma State University, Ardmore, Oklahoma 73401, USA
| | - Kirankumar S Mysore
- The Institute of Agricultural Biosciences, Oklahoma State University, Ardmore, Oklahoma 73401, USA
| | - Marie Garmier
- Université Paris-Saclay, CNRS, INRAE, Université d’Évry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
- Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
| | - Benjamin Gourion
- LIPME, Université de Toulouse, INRAE, CNRS, 31320 Castanet-Tolosan, France
| | - Pascal Ratet
- Université Paris-Saclay, CNRS, INRAE, Université d’Évry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
- Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
| | - Véronique Gruber
- Université Paris-Saclay, CNRS, INRAE, Université d’Évry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
- Université Paris Cité, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France
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13
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Ke X, Xiao H, Peng Y, Wang J, Lv Q, Wang X. Phosphoenolpyruvate reallocation links nitrogen fixation rates to root nodule energy state. Science 2022; 378:971-977. [DOI: 10.1126/science.abq8591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Legume-rhizobium symbiosis in root nodules fixes nitrogen to satisfy the plant’s nitrogen demands. The nodules’ demand for energy is thought to determine nitrogen fixation rates. How this energy state is sensed to modulate nitrogen fixation is unknown. Here, we identified two soybean (
Glycine max
) cystathionine β-synthase domain–containing proteins, nodule AMP sensor 1 (GmNAS1) and NAS1-associated protein 1 (GmNAP1). In the high–nodule energy state, GmNAS1 and GmNAP1 form homodimers that interact with the nuclear factor-Y C (NF-YC) subunit (GmNFYC10a) on mitochondria and reduce its nuclear accumulation. Less nuclear GmNFYC10a leads to lower expression of glycolytic genes involved in pyruvate production, which modulates phosphoenolpyruvate allocation to favor nitrogen fixation. Insight into these pathways may help in the design of leguminous crops that have improved carbon use, nitrogen fixation, and growth.
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Affiliation(s)
- Xiaolong Ke
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Zhengzhou 450046, China
- The Academy for Advanced Interdisplinary Studies, Henan University, Zhengzhou 450046, Henan, China
- Sanya Institute of Henan University, Sanya 572025, Hainan, China
| | - Han Xiao
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Zhengzhou 450046, China
- The Academy for Advanced Interdisplinary Studies, Henan University, Zhengzhou 450046, Henan, China
- Sanya Institute of Henan University, Sanya 572025, Hainan, China
| | - Yaqi Peng
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Zhengzhou 450046, China
- The Academy for Advanced Interdisplinary Studies, Henan University, Zhengzhou 450046, Henan, China
- Sanya Institute of Henan University, Sanya 572025, Hainan, China
| | - Jing Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Zhengzhou 450046, China
| | - Qi Lv
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Zhengzhou 450046, China
- The Academy for Advanced Interdisplinary Studies, Henan University, Zhengzhou 450046, Henan, China
| | - Xuelu Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Zhengzhou 450046, China
- The Academy for Advanced Interdisplinary Studies, Henan University, Zhengzhou 450046, Henan, China
- Sanya Institute of Henan University, Sanya 572025, Hainan, China
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14
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Sauviac L, Rémy A, Huault E, Dalmasso M, Kazmierczak T, Jardinaud MF, Legrand L, Moreau C, Ruiz B, Cazalé AC, Valière S, Gourion B, Dupont L, Gruber V, Boncompagni E, Meilhoc E, Frendo P, Frugier F, Bruand C. A dual legume-rhizobium transcriptome of symbiotic nodule senescence reveals coordinated plant and bacterial responses. PLANT, CELL & ENVIRONMENT 2022; 45:3100-3121. [PMID: 35781677 DOI: 10.1111/pce.14389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 06/26/2022] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
Senescence determines plant organ lifespan depending on aging and environmental cues. During the endosymbiotic interaction with rhizobia, legume plants develop a specific organ, the root nodule, which houses nitrogen (N)-fixing bacteria. Unlike earlier processes of the legume-rhizobium interaction (nodule formation, N fixation), mechanisms controlling nodule senescence remain poorly understood. To identify nodule senescence-associated genes, we performed a dual plant-bacteria RNA sequencing approach on Medicago truncatula-Sinorhizobium meliloti nodules having initiated senescence either naturally (aging) or following an environmental trigger (nitrate treatment or salt stress). The resulting data allowed the identification of hundreds of plant and bacterial genes differentially regulated during nodule senescence, thus providing an unprecedented comprehensive resource of new candidate genes associated with this process. Remarkably, several plant and bacterial genes related to the cell cycle and stress responses were regulated in senescent nodules, including the rhizobial RpoE2-dependent general stress response. Analysis of selected core nodule senescence plant genes allowed showing that MtNAC969 and MtS40, both homologous to leaf senescence-associated genes, negatively regulate the transition between N fixation and senescence. In contrast, overexpression of a gene involved in the biosynthesis of cytokinins, well-known negative regulators of leaf senescence, may promote the transition from N fixation to senescence in nodules.
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Affiliation(s)
- Laurent Sauviac
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INPT-ENSAT, INSA, Castanet-Tolosan, France
| | - Antoine Rémy
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INPT-ENSAT, INSA, Castanet-Tolosan, France
| | - Emeline Huault
- Institute of Plant Sciences-Paris Saclay (IPS2), Paris-Saclay University, CNRS, INRAE, Université de Paris, Gif-sur-Yvette, France
| | | | - Théophile Kazmierczak
- Institute of Plant Sciences-Paris Saclay (IPS2), Paris-Saclay University, CNRS, INRAE, Université de Paris, Gif-sur-Yvette, France
| | - Marie-Françoise Jardinaud
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INPT-ENSAT, INSA, Castanet-Tolosan, France
| | - Ludovic Legrand
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INPT-ENSAT, INSA, Castanet-Tolosan, France
| | - Corentin Moreau
- Institute of Plant Sciences-Paris Saclay (IPS2), Paris-Saclay University, CNRS, INRAE, Université de Paris, Gif-sur-Yvette, France
| | - Bryan Ruiz
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INPT-ENSAT, INSA, Castanet-Tolosan, France
| | - Anne-Claire Cazalé
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INPT-ENSAT, INSA, Castanet-Tolosan, France
| | | | - Benjamin Gourion
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INPT-ENSAT, INSA, Castanet-Tolosan, France
| | | | - Véronique Gruber
- Institute of Plant Sciences-Paris Saclay (IPS2), Paris-Saclay University, CNRS, INRAE, Université de Paris, Gif-sur-Yvette, France
| | | | - Eliane Meilhoc
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INPT-ENSAT, INSA, Castanet-Tolosan, France
| | - Pierre Frendo
- Université Côte d'Azur, INRAE, CNRS, ISA, Nice, France
| | - Florian Frugier
- Institute of Plant Sciences-Paris Saclay (IPS2), Paris-Saclay University, CNRS, INRAE, Université de Paris, Gif-sur-Yvette, France
| | - Claude Bruand
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INPT-ENSAT, INSA, Castanet-Tolosan, France
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15
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Pervent M, Lambert I, Tauzin M, Karouani A, Nigg M, Jardinaud MF, Severac D, Colella S, Martin-Magniette ML, Lepetit M. Systemic control of nodule formation by plant nitrogen demand requires autoregulation-dependent and independent mechanisms. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:7942-7956. [PMID: 34427647 DOI: 10.1093/jxb/erab374] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 08/26/2021] [Indexed: 06/13/2023]
Abstract
In legumes interacting with rhizobia, the formation of symbiotic organs involved in the acquisition of atmospheric nitrogen gas (N2) is dependent on the plant nitrogen (N) demand. We used Medicago truncatula plants cultivated in split-root systems to discriminate between responses to local and systemic N signaling. We evidenced a strong control of nodule formation by systemic N signaling but obtained no clear evidence of a local control by mineral nitrogen. Systemic signaling of the plant N demand controls numerous transcripts involved in root transcriptome reprogramming associated with early rhizobia interaction and nodule formation. SUPER NUMERIC NODULES (SUNN) has an important role in this control, but we found that major systemic N signaling responses remained active in the sunn mutant. Genes involved in the activation of nitrogen fixation are regulated by systemic N signaling in the mutant, explaining why its hypernodulation phenotype is not associated with higher nitrogen fixation of the whole plant. We show that the control of transcriptome reprogramming of nodule formation by systemic N signaling requires other pathway(s) that parallel the SUNN/CLE (CLAVATA3/EMBRYO SURROUNDING REGION-LIKE PEPTIDES) pathway.
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Affiliation(s)
- Marjorie Pervent
- Laboratoire des Symbioses Tropicales et Méditérranéennes INRAE, IRD, CIRAD, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | - Ilana Lambert
- Laboratoire des Symbioses Tropicales et Méditérranéennes INRAE, IRD, CIRAD, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | - Marc Tauzin
- Laboratoire des Symbioses Tropicales et Méditérranéennes INRAE, IRD, CIRAD, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | - Alicia Karouani
- Laboratoire des Symbioses Tropicales et Méditérranéennes INRAE, IRD, CIRAD, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | - Martha Nigg
- Laboratoire des Symbioses Tropicales et Méditérranéennes INRAE, IRD, CIRAD, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | - Marie-Françoise Jardinaud
- Laboratoire des Interactions Plantes Microorganismes INRAE, CNRS, Université de Toulouse, Castanet-Tolosan, France
| | - Dany Severac
- MGX, CNRS, INSERM, Université de Montpellier, Montpellier, France
| | - Stefano Colella
- Laboratoire des Symbioses Tropicales et Méditérranéennes INRAE, IRD, CIRAD, Montpellier SupAgro, Université de Montpellier, Montpellier, France
| | - Marie-Laure Martin-Magniette
- Université Paris-Saclay, CNRS, INRAE, Université d'Evry, Institute of Plant Sciences Paris-Saclay (IPS2), Orsay, France
- Université de Paris, CNRS, INRAE, Institute of Plant Sciences Paris Saclay (IPS2), Orsay, France
- UMR MIA-Paris, AgroParisTech, INRAE, Université Paris-Saclay, Paris, France
| | - Marc Lepetit
- Laboratoire des Symbioses Tropicales et Méditérranéennes INRAE, IRD, CIRAD, Montpellier SupAgro, Université de Montpellier, Montpellier, France
- Institut Sophia Agrobiotech, INRAE, Université Côte d'Azur, CNRS, Sophia-Antipolis, France
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16
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Thilakarathna MS, Cope KR. Split-root assays for studying legume-rhizobia symbioses, rhizodeposition, and belowground nitrogen transfer in legumes. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:5285-5299. [PMID: 33954584 DOI: 10.1093/jxb/erab198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 05/03/2021] [Indexed: 06/12/2023]
Abstract
Split-root assays have been used widely in studies focused on understanding the complex regulatory mechanisms in legume-rhizobia symbioses, root nitrogen rhizodeposition, and belowground nitrogen transfer, and the effects of different biotic/abiotic factors on this symbiotic interaction. This assay allows a plant to have a root system that is physically divided into two distinct sections that are both still attached to a common shoot. Thus, each root section can be treated separately to monitor local and systemic plant responses. Different techniques are used to establish split-root assemblies, including double-pot systems, divided growth pouches, elbow root assembly, twin-tube systems, a single pot or chamber with a partition in the center, and divided agar plates. This review is focused on discussing the various types of split-root assays currently used in legume-based studies, and their associated advantages and limitations. Furthermore, this review also focuses on how split-root assays have been used for studies on nitrogen rhizodeposition, belowground nitrogen transfer, systemic regulation of nodulation, and biotic and abiotic factors affecting legume-rhizobia symbioses.
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Affiliation(s)
- Malinda S Thilakarathna
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada
| | - Kevin R Cope
- Biology and Microbiology Department, South Dakota State University, Brookings, SD, USA
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17
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Westhoek A, Clark LJ, Culbert M, Dalchau N, Griffiths M, Jorrin B, Karunakaran R, Ledermann R, Tkacz A, Webb I, James EK, Poole PS, Turnbull LA. Conditional sanctioning in a legume- Rhizobium mutualism. Proc Natl Acad Sci U S A 2021; 118:e2025760118. [PMID: 33941672 PMCID: PMC8126861 DOI: 10.1073/pnas.2025760118] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Legumes are high in protein and form a valuable part of human diets due to their interaction with symbiotic nitrogen-fixing bacteria known as rhizobia. Plants house rhizobia in specialized root nodules and provide the rhizobia with carbon in return for nitrogen. However, plants usually house multiple rhizobial strains that vary in their fixation ability, so the plant faces an investment dilemma. Plants are known to sanction strains that do not fix nitrogen, but nonfixers are rare in field settings, while intermediate fixers are common. Here, we modeled how plants should respond to an intermediate fixer that was otherwise isogenic and tested model predictions using pea plants. Intermediate fixers were only tolerated when a better strain was not available. In agreement with model predictions, nodules containing the intermediate-fixing strain were large and healthy when the only alternative was a nonfixer, but nodules of the intermediate-fixing strain were small and white when the plant was coinoculated with a more effective strain. The reduction in nodule size was preceded by a lower carbon supply to the nodule even before differences in nodule size could be observed. Sanctioned nodules had reduced rates of nitrogen fixation, and in later developmental stages, sanctioned nodules contained fewer viable bacteria than nonsanctioned nodules. This indicates that legumes can make conditional decisions, most likely by comparing a local nodule-dependent cue of nitrogen output with a global cue, giving them remarkable control over their symbiotic partners.
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Affiliation(s)
- Annet Westhoek
- Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom
- Systems Biology Doctoral Training Centre, Doctoral Training Centre, University of Oxford, OX1 3NP Oxford, United Kingdom
| | - Laura J Clark
- Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom
| | - Michael Culbert
- Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom
| | - Neil Dalchau
- Biological Computation, Microsoft Research Cambridge, CB1 2FB Cambridge, United Kingdom
| | - Megan Griffiths
- Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom
| | - Beatriz Jorrin
- Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom
| | - Ramakrishnan Karunakaran
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, NR4 7UH Norwich, United Kingdom
| | - Raphael Ledermann
- Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom
| | - Andrzej Tkacz
- Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom
| | - Isabel Webb
- Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom
| | - Euan K James
- Ecological Sciences, The James Hutton Institute, DD2 5DA Invergowrie, United Kingdom
| | - Philip S Poole
- Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom;
| | - Lindsay A Turnbull
- Department of Plant Sciences, University of Oxford, OX1 3RB Oxford, United Kingdom;
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18
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McGuiness PN, Reid JB, Foo E. The influence of ethylene, gibberellins and brassinosteroids on energy and nitrogen-fixation metabolites in nodule tissue. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 305:110846. [PMID: 33691972 DOI: 10.1016/j.plantsci.2021.110846] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 02/03/2021] [Accepted: 02/06/2021] [Indexed: 05/12/2023]
Abstract
Legume nodules are a unique plant organ that contain nitrogen-fixing rhizobial bacteria. For this interaction to be mutually beneficial, plant and bacterial metabolism must be precisely co-ordinated. Plant hormones are known to play essential roles during the establishment of legume-rhizobial symbioses but their role in subsequent nodule metabolism has not been explored in any depth. The plant hormones brassinosteroids, ethylene and gibberellins influence legume infection, nodule number and in some cases nodule function. In this paper, the influence of these hormones on nodule metabolism was examined in a series of well characterised pea mutants with altered hormone biosynthesis or response. A targeted set of metabolites involved in nutrient exchange and nitrogen fixation was examined in nodule tissue of mutant and wild type plants. Gibberellin-deficiency had a major negative impact on the level of several major dicarboxylates supplied to rhizobia by the plant and also led to a significant deficit in the amino acids involved in glutamine-aspartate transamination, consistent with the limited bacteroid development and low fixation rate of gibberellin-deficient na mutant nodules. In contrast, no major effects of brassinosteroid-deficiency or ethylene-insensitivity on the key metabolites in these pathways were found. Therefore, although all three hormones influence infection and nodule number, only gibberellin is important for the establishment of a functional nodule metabolome.
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Affiliation(s)
- Peter N McGuiness
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania, 7001, Australia
| | - James B Reid
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania, 7001, Australia
| | - Eloise Foo
- School of Natural Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania, 7001, Australia.
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19
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Gautrat P, Laffont C, Frugier F, Ruffel S. Nitrogen Systemic Signaling: From Symbiotic Nodulation to Root Acquisition. TRENDS IN PLANT SCIENCE 2021; 26:392-406. [PMID: 33358560 DOI: 10.1016/j.tplants.2020.11.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/30/2020] [Accepted: 11/16/2020] [Indexed: 05/27/2023]
Abstract
Plant nutrient acquisition is tightly regulated by resource availability and metabolic needs, implying the existence of communication between roots and shoots to ensure their integration at the whole-plant level. Here, we focus on systemic signaling pathways controlling nitrogen (N) nutrition, achieved both by the root import of mineral N and, in legume plants, through atmospheric N fixation by symbiotic bacteria inside dedicated root nodules. We explore features conserved between systemic pathways repressing or enhancing symbiotic N fixation and the regulation of mineral N acquisition by roots, as well as their integration with other environmental factors, such as phosphate, light, and CO2 availability.
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Affiliation(s)
- Pierre Gautrat
- IPS2 (Institute of Plant Sciences - Paris Saclay), CNRS, INRAe, Université Paris-Diderot, Université d'Evry, Université Paris-Saclay, Bâtiment 630, Gif-sur-Yvette, France
| | - Carole Laffont
- IPS2 (Institute of Plant Sciences - Paris Saclay), CNRS, INRAe, Université Paris-Diderot, Université d'Evry, Université Paris-Saclay, Bâtiment 630, Gif-sur-Yvette, France
| | - Florian Frugier
- IPS2 (Institute of Plant Sciences - Paris Saclay), CNRS, INRAe, Université Paris-Diderot, Université d'Evry, Université Paris-Saclay, Bâtiment 630, Gif-sur-Yvette, France.
| | - Sandrine Ruffel
- BPMP, Univ Montpellier, CNRS, INRAe, Montpellier SupAgro, Montpellier, France.
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20
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Abstract
Rhizobia are a phylogenetically diverse group of soil bacteria that engage in mutualistic interactions with legume plants. Although specifics of the symbioses differ between strains and plants, all symbioses ultimately result in the formation of specialized root nodule organs which host the nitrogen-fixing microsymbionts called bacteroids. Inside nodules, bacteroids encounter unique conditions that necessitate global reprogramming of physiological processes and rerouting of their metabolism. Decades of research have addressed these questions using genetics, omics approaches, and more recently computational modelling. Here we discuss the common adaptations of rhizobia to the nodule environment that define the core principles of bacteroid functioning. All bacteroids are growth-arrested and perform energy-intensive nitrogen fixation fueled by plant-provided C4-dicarboxylates at nanomolar oxygen levels. At the same time, bacteroids are subject to host control and sanctioning that ultimately determine their fitness and have fundamental importance for the evolution of a stable mutualistic relationship.
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