1
|
Pathak PK, Yadav N, Kaladhar VC, Jaiswal R, Kumari A, Igamberdiev AU, Loake GJ, Gupta KJ. The emerging roles of nitric oxide and its associated scavengers-phytoglobins-in plant symbiotic interactions. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:563-577. [PMID: 37843034 DOI: 10.1093/jxb/erad399] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 10/09/2023] [Indexed: 10/17/2023]
Abstract
A key feature in the establishment of symbiosis between plants and microbes is the maintenance of the balance between the production of the small redox-related molecule, nitric oxide (NO), and its cognate scavenging pathways. During the establishment of symbiosis, a transition from a normoxic to a microoxic environment often takes place, triggering the production of NO from nitrite via a reductive production pathway. Plant hemoglobins [phytoglobins (Phytogbs)] are a central tenant of NO scavenging, with NO homeostasis maintained via the Phytogb-NO cycle. While the first plant hemoglobin (leghemoglobin), associated with the symbiotic relationship between leguminous plants and bacterial Rhizobium species, was discovered in 1939, most other plant hemoglobins, identified only in the 1990s, were considered as non-symbiotic. From recent studies, it is becoming evident that the role of Phytogbs1 in the establishment and maintenance of plant-bacterial and plant-fungal symbiosis is also essential in roots. Consequently, the division of plant hemoglobins into symbiotic and non-symbiotic groups becomes less justified. While the main function of Phytogbs1 is related to the regulation of NO levels, participation of these proteins in the establishment of symbiotic relationships between plants and microorganisms represents another important dimension among the other processes in which these key redox-regulatory proteins play a central role.
Collapse
Affiliation(s)
- Pradeep Kumar Pathak
- National Institute for Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | - Nidhi Yadav
- National Institute for Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | | | - Rekha Jaiswal
- National Institute for Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | - Aprajita Kumari
- National Institute for Plant Genome Research, Aruna Asaf Ali Marg, New Delhi, India
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St John's, NL, Canada
| | - Gary J Loake
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
- Centre for Engineering Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | | |
Collapse
|
2
|
Ruiz B, Sauviac L, Brouquisse R, Bruand C, Meilhoc E. Role of Nitric Oxide of Bacterial Origin in the Medicago truncatula-Sinorhizobium meliloti Symbiosis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:887-892. [PMID: 35762680 DOI: 10.1094/mpmi-05-22-0118-sc] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nitric oxide (NO) is a small ubiquitous gaseous molecule that has been found in many host-pathogen interactions. NO has been shown to be part of the defense arsenal of animal cells and more recently of plant cells. To fight this molecular weapon, pathogens have evolved responses consisting of adaptation to NO or degradation of this toxic molecule. More recently, it was shown that NO could also be produced by the pathogen and contributes likewise to the success of the host cell infection. NO is also present during symbiotic interactions. Despite growing knowledge about the role of NO during friendly interactions, data on the specificity of action of NO produced by each partner are scarce, partly due to the multiplicity of NO production systems. In the nitrogen-fixing symbiosis between the soil bacterium Sinorhizobium meliloti and the model legume Medicago truncatula, NO has been detected at all steps of the interaction, where it displays various roles. Both partners contribute to NO production inside the legume root nodules where nitrogen fixation occurs. The study focuses on the role of bacterial NO in this interaction. We used a genetic approach to identify bacterial NO sources in the symbiotic context and to test the phenotype in planta of bacterial mutants affected in NO production. Our results show that only denitrification is a source of bacterial NO in Medicago nodules, giving insight into the role of bacteria-derived NO at different steps of the symbiotic interaction. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Collapse
Affiliation(s)
- Bryan Ruiz
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INSA, Castanet-Tolosan, France
| | - Laurent Sauviac
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INSA, Castanet-Tolosan, France
| | - Renaud Brouquisse
- Institut Sophia Agrobiotech (ISA), INRAE, CNRS, Université Côte d'Azur, 06903 Sophia Antipolis Cedex, France
| | - Claude Bruand
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INSA, Castanet-Tolosan, France
| | - Eliane Meilhoc
- Laboratoire des Interactions Plantes-Microbes-Environnement (LIPME), Université de Toulouse, INRAE, CNRS, INSA, Castanet-Tolosan, France
| |
Collapse
|
3
|
Trebouxia lynnae sp. nov. (Former Trebouxia sp. TR9): Biology and Biogeography of an Epitome Lichen Symbiotic Microalga. BIOLOGY 2022; 11:biology11081196. [PMID: 36009823 PMCID: PMC9405249 DOI: 10.3390/biology11081196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/29/2022] [Accepted: 08/06/2022] [Indexed: 12/02/2022]
Abstract
Two microalgal species, Trebouxia jamesii and Trebouxia sp. TR9, were detected as the main photobionts coexisting in the thalli of the lichen Ramalina farinacea. Trebouxia sp. TR9 emerged as a new taxon in lichen symbioses and was successfully isolated and propagated in in vitro culture and thoroughly investigated. Several years of research have confirmed the taxon Trebouxia sp. TR9 to be a model/reference organism for studying mycobiont−photobiont association patterns in lichen symbioses. Trebouxia sp. TR9 is the first symbiotic, lichen-forming microalga for which an exhaustive characterization of cellular ultrastructure, physiological traits, genetic and genomic diversity is available. The cellular ultrastructure was studied by light, electron and confocal microscopy; physiological traits were studied as responses to different abiotic stresses. The genetic diversity was previously analyzed at both the nuclear and organelle levels by using chloroplast, mitochondrial, and nuclear genome data, and a multiplicity of phylogenetic analyses were carried out to study its intraspecific diversity at a biogeographical level and its specificity association patterns with the mycobiont. Here, Trebouxia sp. TR9 is formally described by applying an integrative taxonomic approach and is presented to science as Trebouxia lynnae, in honor of Lynn Margulis, who was the primary modern proponent for the significance of symbiosis in evolution. The complete set of analyses that were carried out for its characterization is provided.
Collapse
|
4
|
Amelioration of Chlorpyrifos-Induced Toxicity in Brassica juncea L. by Combination of 24-Epibrassinolide and Plant-Growth-Promoting Rhizobacteria. Biomolecules 2021; 11:biom11060877. [PMID: 34204730 PMCID: PMC8231531 DOI: 10.3390/biom11060877] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 01/24/2023] Open
Abstract
Pervasive use of chlorpyrifos (CP), an organophosphorus pesticide, has been proven to be fatal for plant growth, especially at higher concentrations. CP poisoning leads to growth inhibition, chlorosis, browning of roots and lipid and protein degradation, along with membrane dysfunction and nuclear damage. Plants form a linking bridge between the underground and above-ground communities to escape from the unfavourable conditions. Association with beneficial rhizobacteria promotes the growth and development of the plants. Plant hormones are crucial regulators of basically every aspect of plant development. The growing significance of plant hormones in mediating plant-microbe interactions in stress recovery in plants has been extensively highlighted. Hence, the goal of the current study was to investigate the effect of 24-epibrassinolide (EBL) and PGPRs (Pseudomonas aeruginosa (Ma), Burkholderia gladioli (Mb)) on growth and the antioxidative defence system of CP-stressed Brassica juncea L. seedlings. CP toxicity reduced the germination potential, hypocotyl and radicle development and vigour index, which was maximally recuperated after priming with EBL and Mb. CP-exposed seedlings showed higher levels of superoxide anion (O2-), hydrogen peroxide (H2O2), lipid peroxidation and electrolyte leakage (EL) and a lower level of nitric oxide (NO). In-vivo visualisation of CP-stressed seedlings using a light and fluorescent microscope also revealed the increase in O2-, H2O2 and lipid peroxidation, and decreased NO levels. The combination of EBL and PGPRs reduced the reactive oxygen species (ROS) and malondialdehyde (MDA) contents and improved the NO level. In CP-stressed seedlings, increased gene expression of defence enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APOX), glutathione peroxidase (GPOX), dehydroascorbate reductase (DHAR) and glutathione reductase (GPOX) was seen, with the exception of catalase (CAT) on supplementation with EBL and PGPRs. The activity of nitrate reductase (NR) was likewise shown to increase after treatment with EBL and PGPRs. The results obtained from the present study substantiate sufficient evidence regarding the positive association of EBL and PGPRs in amelioration of CP-induced oxidative stress in Brassica juncea seedlings by strengthening the antioxidative defence machinery.
Collapse
|
5
|
Rhizobia: highways to NO. Biochem Soc Trans 2021; 49:495-505. [PMID: 33544133 DOI: 10.1042/bst20200989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 02/02/2023]
Abstract
The interaction between rhizobia and their legume host plants conduces to the formation of specialized root organs called nodules where rhizobia differentiate into bacteroids which fix atmospheric nitrogen to the benefit of the plant. This beneficial symbiosis is of importance in the context of sustainable agriculture as legumes do not require the addition of nitrogen fertilizer to grow. Interestingly, nitric oxide (NO) has been detected at various steps of the rhizobium-legume symbiosis where it has been shown to play multifaceted roles. Both bacterial and plant partners are involved in NO synthesis in nodules. To better understand the role of NO, and in particular the role of bacterial NO, at all steps of rhizobia-legumes interaction, the enzymatic sources of NO have to be elucidated. In this review, we discuss different enzymatic reactions by which rhizobia may potentially produce NO. We argue that there is most probably no NO synthase activity in rhizobia, and that instead the NO2- reductase nirK, which is part of the denitrification pathway, is the main bacterial source of NO. The nitrate assimilation pathway might contribute to NO production but only when denitrification is active. The different approaches to measure NO in rhizobia are also addressed.
Collapse
|
6
|
Berger A, Boscari A, Horta Araújo N, Maucourt M, Hanchi M, Bernillon S, Rolin D, Puppo A, Brouquisse R. Plant Nitrate Reductases Regulate Nitric Oxide Production and Nitrogen-Fixing Metabolism During the Medicago truncatula-Sinorhizobium meliloti Symbiosis. FRONTIERS IN PLANT SCIENCE 2020; 11:1313. [PMID: 33013954 PMCID: PMC7500168 DOI: 10.3389/fpls.2020.01313] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 08/11/2020] [Indexed: 05/08/2023]
Abstract
Nitrate reductase (NR) is the first enzyme of the nitrogen reduction pathway in plants, leading to the production of ammonia. However, in the nitrogen-fixing symbiosis between legumes and rhizobia, atmospheric nitrogen (N2) is directly reduced to ammonia by the bacterial nitrogenase, which questions the role of NR in symbiosis. Next to that, NR is the best-characterized source of nitric oxide (NO) in plants, and NO is known to be produced during the symbiosis. In the present study, we first surveyed the three NR genes (MtNR1, MtNR2, and MtNR3) present in the Medicago truncatula genome and addressed their expression, activity, and potential involvement in NO production during the symbiosis between M. truncatula and Sinorhizobium meliloti. Our results show that MtNR1 and MtNR2 gene expression and activity are correlated with NO production throughout the symbiotic process and that MtNR1 is particularly involved in NO production in mature nodules. Moreover, NRs are involved together with the mitochondrial electron transfer chain in NO production throughout the symbiotic process and energy regeneration in N2-fixing nodules. Using an in vivo NMR spectrometric approach, we show that, in mature nodules, NRs participate also in the regulation of energy state, cytosolic pH, carbon and nitrogen metabolism under both normoxia and hypoxia. These data point to the importance of NR activity for the N2-fixing symbiosis and provide a first explanation of its role in this process.
Collapse
Affiliation(s)
- Antoine Berger
- Institut Sophia Agrobiotech, UMR INRAE 1355, Université Côte d’Azur, CNRS, Sophia Antipolis, France
- Department of Horticultural Science, University of Florida, Gainesville, FL, United States
| | - Alexandre Boscari
- Institut Sophia Agrobiotech, UMR INRAE 1355, Université Côte d’Azur, CNRS, Sophia Antipolis, France
| | - Natasha Horta Araújo
- Institut Sophia Agrobiotech, UMR INRAE 1355, Université Côte d’Azur, CNRS, Sophia Antipolis, France
| | - Mickaël Maucourt
- Univ. Bordeaux INRAE, UMR Biologie du Fruit et Pathologie, Villenave d’Ornon, France
| | - Mohamed Hanchi
- Institut Sophia Agrobiotech, UMR INRAE 1355, Université Côte d’Azur, CNRS, Sophia Antipolis, France
| | - Stéphane Bernillon
- PMB-Metabolome, INRAE, Bordeaux Metabolome Facility, Villenave d’Ornon, France
| | - Dominique Rolin
- Univ. Bordeaux INRAE, UMR Biologie du Fruit et Pathologie, Villenave d’Ornon, France
- PMB-Metabolome, INRAE, Bordeaux Metabolome Facility, Villenave d’Ornon, France
| | - Alain Puppo
- Institut Sophia Agrobiotech, UMR INRAE 1355, Université Côte d’Azur, CNRS, Sophia Antipolis, France
| | - Renaud Brouquisse
- Institut Sophia Agrobiotech, UMR INRAE 1355, Université Côte d’Azur, CNRS, Sophia Antipolis, France
- *Correspondence: Renaud Brouquisse,
| |
Collapse
|
7
|
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.
Collapse
|
8
|
Bruand C, Meilhoc E. Nitric oxide in plants: pro- or anti-senescence. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:4419-4427. [PMID: 30868162 DOI: 10.1093/jxb/erz117] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 03/08/2019] [Indexed: 06/09/2023]
Abstract
Senescence is a regulated process of tissue degeneration that can affect any plant organ and consists of the degradation and remobilization of molecules to other growing tissues. Senescent organs display changes at the microscopic level as well as modifications to internal cellular structure and differential gene expression. A large number of factors influencing senescence have been described including age, nutrient supply, and environmental interactions. Internal factors such as phytohormones also affect the timing of leaf senescence. A link between the senescence process and the production of nitric oxide (NO) in senescing tissues has been known for many years. Remarkably, this link can be either a positive or a negative correlation depending upon the organ. NO can be both a signaling or a toxic molecule and is known to have multiple roles in plants; this review considers the duality of NO roles in the senescence process of two different plant organs, namely the leaves and root nodules.
Collapse
Affiliation(s)
- Claude Bruand
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), Université de Toulouse, INRA, CNRS, INSA, Castanet-Tolosan, France
| | - Eliane Meilhoc
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), Université de Toulouse, INRA, CNRS, INSA, Castanet-Tolosan, France
| |
Collapse
|
9
|
Zou H, Zhang NN, Pan Q, Zhang JH, Chen J, Wei GH. Hydrogen Sulfide Promotes Nodulation and Nitrogen Fixation in Soybean-Rhizobia Symbiotic System. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:972-985. [PMID: 31204904 DOI: 10.1094/mpmi-01-19-0003-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The rhizobium-legume symbiotic system is crucial for nitrogen cycle balance in agriculture. Hydrogen sulfide (H2S), a gaseous signaling molecule, may regulate various physiological processes in plants. However, whether H2S has regulatory effect in this symbiotic system remains unknown. Herein, we investigated the possible role of H2S in the symbiosis between soybean (Glycine max) and rhizobium (Sinorhizobium fredii). Our results demonstrated that an exogenous H2S donor (sodium hydrosulfide [NaHS]) treatment promoted soybean growth, nodulation, and nitrogenase (Nase) activity. Western blotting analysis revealed that the abundance of Nase component nifH was increased by NaHS treatment in nodules. Quantitative real-time polymerase chain reaction data showed that NaHS treatment upregulated the expressions of symbiosis-related genes nodA, nodC, and nodD of S. fredii. In addition, expression of soybean nodulation marker genes, including early nodulin 40 (GmENOD40), ERF required for nodulation (GmERN), nodulation signaling pathway 2b (GmNSP2b), and nodulation inception genes (GmNIN1a, GmNIN2a, and GmNIN2b), were upregulated. Moreover, the expressions of glutamate synthase (GmGOGAT), asparagine synthase (GmAS), nitrite reductase (GmNiR), ammonia transporter (GmSAT1), leghemoglobin (GmLb), and nifH involved in nitrogen metabolism were upregulated in NaHS-treated soybean roots and nodules. Together, our results suggested that H2S may act as a positive signaling molecule in the soybean-rhizobia symbiotic system and enhance the system's nitrogen fixation ability.
Collapse
Affiliation(s)
- Hang Zou
- 1State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
- 2Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, Yangling, Shaanxi 712100, PR China
| | - Ni-Na Zhang
- 3State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China
| | - Qing Pan
- 1State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
- 2Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, Yangling, Shaanxi 712100, PR China
| | - Jian-Hua Zhang
- 4School of Life Sciences and State Key Laboratory of Agrobiotechnology, the Chinese University of Hong Kong, Hong Kong
- 5Department of Biology, Hong Kong Baptist University, Hong Kong
| | - Juan Chen
- 1State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
- 3State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, P.R. China
- 4School of Life Sciences and State Key Laboratory of Agrobiotechnology, the Chinese University of Hong Kong, Hong Kong
| | - Ge-Hong Wei
- 1State Key Laboratory of Crop Stress Biology in Arid Areas, College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, PR China
- 2Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, Yangling, Shaanxi 712100, PR China
| |
Collapse
|
10
|
Ruiz B, Le Scornet A, Sauviac L, Rémy A, Bruand C, Meilhoc E. The Nitrate Assimilatory Pathway in Sinorhizobium meliloti: Contribution to NO Production. Front Microbiol 2019; 10:1526. [PMID: 31333627 PMCID: PMC6616083 DOI: 10.3389/fmicb.2019.01526] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 06/18/2019] [Indexed: 11/13/2022] Open
Abstract
The interaction between rhizobia and their legume host plants culminates in the formation of specialized root organs called nodules in which differentiated endosymbiotic bacteria (bacteroids) fix atmospheric nitrogen to the benefit of the plant. Interestingly, nitric oxide (NO) has been detected at various steps of the rhizobium-legume symbiosis where it has been shown to play multifaceted roles. It is recognized that both bacterial and plant partners of the Sinorhizobium meliloti–Medicago truncatula symbiosis are involved in NO synthesis in nodules. S. meliloti can also produce NO from nitrate when living as free cells in the soil. S. meliloti does not possess any NO synthase gene in its genome. Instead, the denitrification pathway is often described as the main driver of NO production with nitrate as substrate. This pathway includes the periplasmic nitrate reductase (Nap) which reduces nitrate into nitrite, and the nitrite reductase (Nir) which reduces nitrite into NO. However, additional genes encoding putative nitrate and nitrite reductases (called narB and nirB, respectively) have been identified in the S. meliloti genome. Here we examined the conditions where these genes are expressed, investigated their involvement in nitrate assimilation and NO synthesis in culture and their potential role in planta. We found that narB and nirB are expressed under aerobic conditions in absence of ammonium in the medium and most likely belong to the nitrate assimilatory pathway. Even though these genes are clearly expressed in the fixation zone of legume root nodule, they do not play a crucial role in symbiosis. Our results support the hypothesis that in S. meliloti, denitrification remains the main enzymatic way to produce NO while the assimilatory pathway involving NarB and NirB participates indirectly to NO synthesis by cooperating with the denitrification pathway.
Collapse
Affiliation(s)
- Bryan Ruiz
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), INRA, CNRS, INSA, Université de Toulouse, Castanet-Tolosan, France
| | - Alexandre Le Scornet
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), INRA, CNRS, INSA, Université de Toulouse, Castanet-Tolosan, France
| | - Laurent Sauviac
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), INRA, CNRS, INSA, Université de Toulouse, Castanet-Tolosan, France
| | - Antoine Rémy
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), INRA, CNRS, INSA, Université de Toulouse, Castanet-Tolosan, France
| | - Claude Bruand
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), INRA, CNRS, INSA, Université de Toulouse, Castanet-Tolosan, France
| | - Eliane Meilhoc
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), INRA, CNRS, INSA, Université de Toulouse, Castanet-Tolosan, France
| |
Collapse
|
11
|
Berger A, Brouquisse R, Pathak PK, Hichri I, Singh I, Bhatia S, Boscari A, Igamberdiev AU, Gupta KJ. Pathways of nitric oxide metabolism and operation of phytoglobins in legume nodules: missing links and future directions. PLANT, CELL & ENVIRONMENT 2018. [PMID: 29351361 DOI: 10.1111/pce.13151] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/14/2018] [Accepted: 01/15/2018] [Indexed: 05/04/2023]
Abstract
The interaction between legumes and rhizobia leads to the establishment of a beneficial symbiotic relationship. Recent advances in legume - rhizobium symbiosis revealed that various reactive oxygen and nitrogen species including nitric oxide (NO) play important roles during this process. Nodule development occurs with a transition from a normoxic environment during the establishment of symbiosis to a microoxic environment in functional nodules. Such oxygen dynamics are required for activation and repression of various NO production and scavenging pathways. Both the plant and bacterial partners participate in the synthesis and degradation of NO. However, the pathways of NO production and degradation as well as their cross-talk and involvement in the metabolism are still a matter of debate. The plant-originated reductive pathways are known to contribute to the NO production in nodules under hypoxic conditions. Non-symbiotic hemoglobin (phytoglobin) (Pgb) possesses high NO oxygenation capacity, buffers and scavenges NO. Its operation, through a respiratory cycle called Pgb-NO cycle, leads to the maintenance of redox and energy balance in nodules. The role of Pgb/NO cycle under fluctuating NO production from soil needs further investigation for complete understanding of NO regulatory mechanism governing nodule development to attain optimal food security under changing environment.
Collapse
Affiliation(s)
- Antoine Berger
- Institut Sophia Agrobiotech, INRA, CNRS, Université Côte d'Azur, 06903, Sophia Antipolis Cedex, France
| | - Renaud Brouquisse
- Institut Sophia Agrobiotech, INRA, CNRS, Université Côte d'Azur, 06903, Sophia Antipolis Cedex, France
| | - Pradeep Kumar Pathak
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, 110067, New Delhi, India
| | - Imène Hichri
- Institut Sophia Agrobiotech, INRA, CNRS, Université Côte d'Azur, 06903, Sophia Antipolis Cedex, France
| | - Inderjit Singh
- Department of Environmental Studies, University of Delhi, Delhi, 110007, India
| | - Sabhyata Bhatia
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, 110067, New Delhi, India
| | - Alexandre Boscari
- Institut Sophia Agrobiotech, INRA, CNRS, Université Côte d'Azur, 06903, Sophia Antipolis Cedex, France
| | - Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL, A1B3X9, Canada
| | | |
Collapse
|
12
|
Nitric Oxide as a Signaling Molecule in Plant-Bacterial Interactions. PLANT MICROBIOME: STRESS RESPONSE 2018. [DOI: 10.1007/978-981-10-5514-0_8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
|