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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.
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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
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Prabha R, Singh DP, Gupta S, Gupta VK, El-Enshasy HA, Verma MK. Rhizosphere Metagenomics of Paspalum scrobiculatum L. (Kodo Millet) Reveals Rhizobiome Multifunctionalities. Microorganisms 2019; 7:microorganisms7120608. [PMID: 31771141 PMCID: PMC6956225 DOI: 10.3390/microorganisms7120608] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 10/15/2019] [Indexed: 12/23/2022] Open
Abstract
Multifunctionalities linked with the microbial communities associated with the millet crop rhizosphere has remained unexplored. In this study, we are analyzing microbial communities inhabiting rhizosphere of kodo millet and their associated functions and its impact over plant growth and survival. Metagenomics of Paspalum scrobiculatum L.(kodo millet) rhizopshere revealed taxonomic communities with functional capabilities linked to support growth and development of the plants under nutrient-deprived, semi-arid and dry biotic conditions. Among 65 taxonomically diverse phyla identified in the rhizobiome, Actinobacteria were the most abundant followed by the Proteobacteria. Functions identified for different genes/proteins led to revelations that multifunctional rhizobiome performs several metabolic functions including carbon fixation, nitrogen, phosphorus, sulfur, iron and aromatic compound metabolism, stress response, secondary metabolite synthesis and virulence, disease, and defense. Abundance of genes linked with N, P, S, Fe and aromatic compound metabolism and phytohormone synthesis—along with other prominent functions—clearly justifies growth, development, and survival of the plants under nutrient deprived dry environment conditions. The dominance of actinobacteria, the known antibiotic producing communities shows that the kodo rhizobiome possesses metabolic capabilities to defend themselves against biotic stresses. The study opens avenues to revisit multi-functionalities of the crop rhizosphere for establishing link between taxonomic abundance and targeted functions that help plant growth and development in stressed and nutrient deprived soil conditions. It further helps in understanding the role of rhizosphere microbiome in adaptation and survival of plants in harsh abiotic conditions.
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Affiliation(s)
- Ratna Prabha
- Chhattisgarh Swami Vivekananda Technical University, Bhilai, Chhattisgarh 491107, India; (R.P.); (M.K.V.)
| | - Dhananjaya P. Singh
- ICAR-National Bureau of Agriculturally Important Microorganisms, Indian Council of Agricultural Research, Kushmaur, Maunath Bhanjan 275101, UP, India
- Correspondence:
| | - Shailendra Gupta
- Department of Systems Biology and Bioinformatics, University of Rostock, Rostock 18057, Germany;
| | - Vijai Kumar Gupta
- Department of Chemistry and Biotechnology, ERA Chair of Green Chemistry, Tallinn University of Technology, 12618 Tallinn, Estonia;
| | - Hesham A. El-Enshasy
- Institute of Bioproduct Development, Universiti Teknologi Malaysia, Skudai 81310, Johor Bahru, Johor, Malaysia;
| | - Mukesh K. Verma
- Chhattisgarh Swami Vivekananda Technical University, Bhilai, Chhattisgarh 491107, India; (R.P.); (M.K.V.)
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Nouioui I, Cortés-albayay C, Carro L, Castro JF, Gtari M, Ghodhbane-Gtari F, Klenk HP, Tisa LS, Sangal V, Goodfellow M. Genomic Insights Into Plant-Growth-Promoting Potentialities of the Genus Frankia. Front Microbiol 2019; 10:1457. [PMID: 31333602 PMCID: PMC6624747 DOI: 10.3389/fmicb.2019.01457] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 06/11/2019] [Indexed: 12/19/2022] Open
Abstract
This study was designed to determine the plant growth promoting (PGP) potential of members of the genus Frankia. To this end, the genomes of 21 representative strains were examined for genes associated directly or indirectly with plant growth. All of the Frankia genomes contained genes that encoded for products associated with the biosynthesis of auxins [indole-3-glycerol phosphate synthases, anthranilate phosphoribosyltransferases (trpD), anthranilate synthases, and aminases (trpA and B)], cytokinins (11 well-conserved genes within the predicted biosynthetic gene cluster), siderophores, and nitrogenases (nif operon except for atypical Frankia) as well as genes that modulate the effects of biotic and abiotic environmental stress (e.g., alkyl hydroperoxide reductases, aquaporin Z, heat shock proteins). In contrast, other genes were associated with strains assigned to one or more of four host-specific clusters. The genes encoding for phosphate solubilization (e.g., low-affinity inorganic phosphate transporters) and lytic enzymes (e.g., cellulases) were found in Frankia cluster 1 genomes, while other genes were found only in cluster 3 genomes (e.g., alkaline phosphatases, extracellular endoglucanases, pectate lyases) or cluster 4 and subcluster 1c genomes (e.g., NAD(P) transhydrogenase genes). Genes encoding for chitinases were found only in the genomes of the type strains of Frankia casuarinae, F. inefficax, F. irregularis, and F. saprophytica. In short, these in silico genome analyses provide an insight into the PGP abilities of Frankia strains of known taxonomic provenance. This is the first study designed to establish the underlying genetic basis of cytokinin production in Frankia strains. Also, the discovery of additional genes in the biosynthetic gene cluster involved in cytokinin production opens up the prospect that Frankia may have novel molecular mechanisms for cytokinin biosynthesis.
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Affiliation(s)
- Imen Nouioui
- School of Natural and Environmental Sciences, Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Carlos Cortés-albayay
- School of Natural and Environmental Sciences, Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Lorena Carro
- Microbiology and Genetics Department, Universidad de Salamanca, Salamanca, Spain
| | - Jean Franco Castro
- The Chilean Collection of Microbial Genetic Resources (CChRGM), Instituto de Investigaciones Agropecuarias (INIA) – Quilamapu, Chillán, Chile
| | - Maher Gtari
- Institut National des Sciences Appliquées et de Technologie, Université de Carthage Centre Urbain Nord, Tunis, Tunisia
| | - Faten Ghodhbane-Gtari
- Institut National des Sciences Appliquées et de Technologie, Université de Carthage Centre Urbain Nord, Tunis, Tunisia
- Laboratoire Microorganismes et Biomolécules Actives, Faculté de Sciences de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Hans-Peter Klenk
- School of Natural and Environmental Sciences, Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Louis S. Tisa
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, United States
| | - Vartul Sangal
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | - Michael Goodfellow
- School of Natural and Environmental Sciences, Faculty of Science, Agriculture and Engineering, Newcastle University, Newcastle upon Tyne, United Kingdom
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Exploitation of Fungi and Actinobacteria for Sustainable Agriculture. Microb Biotechnol 2017. [DOI: 10.1007/978-981-10-6847-8_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Genomic approaches toward understanding the actinorhizal symbiosis: an update on the status of the Frankia genomes. Symbiosis 2016. [DOI: 10.1007/s13199-016-0390-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Furnholm TR, Tisa LS. The ins and outs of metal homeostasis by the root nodule actinobacterium Frankia. BMC Genomics 2014; 15:1092. [PMID: 25495525 PMCID: PMC4531530 DOI: 10.1186/1471-2164-15-1092] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 11/19/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Frankia are actinobacteria that form a symbiotic nitrogen-fixing association with actinorhizal plants, and play a significant role in actinorhizal plant colonization of metal contaminated areas. Many Frankia strains are known to be resistant to several toxic metals and metalloids including Pb(2+), Al(+3), SeO2, Cu(2+), AsO4, and Zn(2+). With the availability of eight Frankia genome databases, comparative genomics approaches employing phylogeny, amino acid composition analysis, and synteny were used to identify metal homeostasis mechanisms in eight Frankia strains. Characterized genes from the literature and a meta-analysis of 18 heavy metal gene microarray studies were used for comparison. RESULTS Unlike most bacteria, Frankia utilize all of the essential trace elements (Ni, Co, Cu, Se, Mo, B, Zn, Fe, and Mn) and have a comparatively high percentage of metalloproteins, particularly in the more metal resistant strains. Cation diffusion facilitators, being one of the few known metal resistance mechanisms found in the Frankia genomes, were strong candidates for general divalent metal resistance in all of the Frankia strains. Gene duplication and amino acid substitutions that enhanced the metal affinity of CopA and CopCD proteins may be responsible for the copper resistance found in some Frankia strains. CopA and a new potential metal transporter, DUF347, may be involved in the particularly high lead tolerance in Frankia. Selenite resistance involved an alternate sulfur importer (CysPUWA) that prevents sulfur starvation, and reductases to produce elemental selenium. The pattern of arsenate, but not arsenite, resistance was achieved by Frankia using the novel arsenite exporter (AqpS) previously identified in the nitrogen-fixing plant symbiont Sinorhizobium meliloti. Based on the presence of multiple tellurite resistance factors, a new metal resistance (tellurite) was identified and confirmed in Frankia. CONCLUSIONS Each strain had a unique combination of metal import, binding, modification, and export genes that explain differences in patterns of metal resistance between strains. Frankia has achieved similar levels of metal and metalloid resistance as bacteria from highly metal-contaminated sites. From a bioremediation standpoint, it is important to understand mechanisms that allow the endosymbiont to survive and infect actinorhizal plants in metal contaminated soils.
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Affiliation(s)
- Teal R Furnholm
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, USA.
| | - Louis S Tisa
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH, USA.
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Ghodhbane-Gtari F, Hezbri K, Ktari A, Sbissi I, Beauchemin N, Gtari M, Tisa LS. Contrasted reactivity to oxygen tensions in Frankia sp. strain CcI3 throughout nitrogen fixation and assimilation. BIOMED RESEARCH INTERNATIONAL 2014; 2014:568549. [PMID: 24987692 PMCID: PMC4058466 DOI: 10.1155/2014/568549] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Revised: 04/28/2014] [Accepted: 05/15/2014] [Indexed: 11/18/2022]
Abstract
Reconciling the irreconcilable is a primary struggle in aerobic nitrogen-fixing bacteria. Although nitrogenase is oxygen and reactive oxygen species-labile, oxygen tension is required to sustain respiration. In the nitrogen-fixing Frankia, various strategies have been developed through evolution to control the respiration and nitrogen-fixation balance. Here, we assessed the effect of different oxygen tensions on Frankia sp. strain CcI3 growth, vesicle production, and gene expression under different oxygen tensions. Both biomass and vesicle production were correlated with elevated oxygen levels under both nitrogen-replete and nitrogen-deficient conditions. The mRNA levels for the nitrogenase structural genes (nifHDK) were high under hypoxic and hyperoxic conditions compared to oxic conditions. The mRNA level for the hopanoid biosynthesis genes (sqhC and hpnC) was also elevated under hyperoxic conditions suggesting an increase in the vesicle envelope. Under nitrogen-deficient conditions, the hup2 mRNA levels increased with hyperoxic environment, while hup1 mRNA levels remained relatively constant. Taken together, these results indicate that Frankia protects nitrogenase by the use of multiple mechanisms including the vesicle-hopanoid barrier and increased respiratory protection.
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Affiliation(s)
- Faten Ghodhbane-Gtari
- Laboratoire Microorganismes et Biomolécules Actives, Université Tunis El Manar (FST) and Université Carthage (INSAT), Campus Universitaire, 2092 Tunis, Tunisia
- Department of Molecular, Cellular & Biomedical Sciences, University of New Hampshire, 46 College Road, Durham, NH 03824-2617, USA
| | - Karima Hezbri
- Laboratoire Microorganismes et Biomolécules Actives, Université Tunis El Manar (FST) and Université Carthage (INSAT), Campus Universitaire, 2092 Tunis, Tunisia
| | - Amir Ktari
- Laboratoire Microorganismes et Biomolécules Actives, Université Tunis El Manar (FST) and Université Carthage (INSAT), Campus Universitaire, 2092 Tunis, Tunisia
| | - Imed Sbissi
- Laboratoire Microorganismes et Biomolécules Actives, Université Tunis El Manar (FST) and Université Carthage (INSAT), Campus Universitaire, 2092 Tunis, Tunisia
| | - Nicholas Beauchemin
- Department of Molecular, Cellular & Biomedical Sciences, University of New Hampshire, 46 College Road, Durham, NH 03824-2617, USA
| | - Maher Gtari
- Laboratoire Microorganismes et Biomolécules Actives, Université Tunis El Manar (FST) and Université Carthage (INSAT), Campus Universitaire, 2092 Tunis, Tunisia
- Department of Molecular, Cellular & Biomedical Sciences, University of New Hampshire, 46 College Road, Durham, NH 03824-2617, USA
| | - Louis S. Tisa
- Department of Molecular, Cellular & Biomedical Sciences, University of New Hampshire, 46 College Road, Durham, NH 03824-2617, USA
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8
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Reyes RDH, Cafaro MJ. Paratrechina longicornis ants in a tropical dry forest harbor specific Actinobacteria diversity. J Basic Microbiol 2014; 55:11-21. [PMID: 24771570 DOI: 10.1002/jobm.201300785] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 01/10/2014] [Indexed: 11/08/2022]
Abstract
The diversity of Actinobacteria associated with Paratrechina longicornis, an ant species that prefers a high protein diet, in a subtropical dry forest (Guánica, Puerto Rico) was determined by culture methods and by 16S rDNA clone libraries. The results of both methodologies were integrated to obtain a broader view of the diversity. Streptomyces, Actinomadura, Nocardia, Ornithinimicrobium, Tsukamurella, Brevibacterium, Saccharopolyspora, Nocardioides, Microbacterium, Leifsonia, Pseudonocardia, Corynebacterium, Geodermatophilus, Amycolatopsis, and Nonomuraea were found associated with the ants. The genera Streptomyces and Actinomadura were the most abundant. Also, the diversity of Actinobacteria associated with the soil surrounding the nest was determined using 16S rDNA clone libraries. In total, 27 genera of Actinobacteria were associated with the nest soils. A dominant genus was not observed in any of the soil samples. We compared statistically the Actinobacteria communities among P. longicornis nests and each nest with its surrounding soil using the clone libraries data. We established that the communities associated with the ants were consistent and significantly different from those found in the soil in which the ants live.
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Richau KH, Kudahettige RL, Pujic P, Kudahettige NP, Sellstedt A. Structural and gene expression analyses of uptake hydrogenases and other proteins involved in nitrogenase protection in Frankia. J Biosci 2013; 38:703-12. [DOI: 10.1007/s12038-013-9372-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- K H Richau
- Department of Plant Physiology, UPSC, Umea University, S-90187 Umea, Sweden
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10
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Pawlowski K, Bogusz D, Ribeiro A, Berry AM. Progress on research on actinorhizal plants. FUNCTIONAL PLANT BIOLOGY : FPB 2011; 38:633-638. [PMID: 32480917 DOI: 10.1071/fp11066] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 05/10/2011] [Indexed: 06/11/2023]
Abstract
In recent years, our understanding of the plant side of actinorhizal symbioses has evolved rapidly. No homologues of the common nod genes from rhizobia were found in the three Frankia genomes published so far, which suggested that Nod factor-like molecules would not be used in the infection of actinorhizal plants by Frankia. However, work on chimeric transgenic plants indicated that Frankia Nod factor equivalents signal via the same transduction pathway as rhizobial Nod factors. The role of auxin in actinorhizal nodule formation differs from that in legume nodulation. Great progress has been made in the analysis of pathogenesis-related and stress-related gene expression in nodules. Research on nodule physiology has shown the structural and metabolic diversity of actinorhizal nodules from different phylogenetic branches. The onset of large-scale nodule transcriptome analysis in different actinorhizal systems will provide access to more information on the symbiosis and its evolution.
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Affiliation(s)
| | - Didier Bogusz
- Groupe Rhizogenèse, Unité Mixte de Recherche Diversité et Adaptation des Plantes Cultivées, Institut de Recherche pour le Développement, 911 avenue Agropolis, BP 5045, 34394 Montpellier Cedex 5, France
| | - Ana Ribeiro
- ECO-BIO/Tropical Research Institute, Av. da República (EAN), Quinta do Marquês, 2784-505 Oeiras, Portugal
| | - Alison M Berry
- Department of Plant Sciences, University of California, Davis, CA 95616, USA
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Huang Y, Benson DR. Growth and development of Frankia spp. strain CcI3 at the single-hypha level in liquid culture. Arch Microbiol 2011; 194:21-8. [PMID: 21773799 DOI: 10.1007/s00203-011-0734-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 06/23/2011] [Accepted: 07/04/2011] [Indexed: 10/18/2022]
Abstract
Filamentous actinobacteria from the genus Frankia grow by hyphal tip extension and branching. The growth kinetics and branching pattern of Frankia are not well studied, especially at the early stages of mycelial development. Here, we compare the growth of Frankia sp. strain CcI3 in liquid cultures with and without proteose peptone #3 (PP3) using time-lapse photomicrography and image analysis. Individual hyphae showed a pseudolinear increase in length at early stages of development, whereas at the mycelial level, the aggregate length of hyphae described an exponential rate before slowing. Growth based on optical density or microscopic observations was similar in medium with or without PP3. However, PP3 altered the pattern of mycelial development by increasing branching. Distances between the hyphal apex and first branches were on average shorter in PP3-containing media. The final interbranch distances were also shorter in PP3 medium indicating that hyphae tended to branch earlier and more often when supplemented with PP3 to give a more compact mycelium. Vesicle development in nitrogen-fixing cultures limited cell expansion as a result of vesicles truncating growth on new branches. The results provide some explanation for the growth kinetics of Frankia and some indication of how growth rates may be improved.
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Affiliation(s)
- Ying Huang
- Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Rd., Unit 3125, Storrs, CT 06269, USA
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12
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Coats V, Schwintzer CR, Tjepkema JD. Truncated hemoglobins in Frankia CcI3: effects of nitrogen source, oxygen concentration, and nitric oxide. Can J Microbiol 2009; 55:867-73. [PMID: 19767859 DOI: 10.1139/w09-042] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Frankia strain CcI3 produces 2 truncated hemoglobins, HbN and HbO. Using ion-exchange chromatography, we characterized the expression of the relative amounts of HbN and HbO in -N (nitrogen-fixing) cultures and +N (nitrogen-supplemented) cultures. The -N cultures maintained an approximately constant ratio of HbO to HbN throughout the life of the culture, with HbO constituting 80%-85% of the total hemoglobin produced. In contrast, in +N cultures, HbN was observed to increase over time and HbO decreased. Total hemoglobin as a fraction of total protein was approximately constant throughout the growth phase in -N cultures, while it decreased somewhat in +N cultures. Subjecting -N cultures to a NO generator resulted in increased production of HbN, relative to the controls. Nitrite accumulated in +N cultures, but not in -N cultures. This suggests that the greater amount of HbN in +N cultures might be due to NO produced by the reduction of nitrite. The effects of O2 concentration were determined in +N cultures. Cultures grown in 1% O2 produced about 4 times more HbO than cultures grown in 20% O2. Overall, these results provide evidence for a role of HbN in NO oxidation and for a role of HbO in adaptation to low oxygen concentrations.
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Affiliation(s)
- Vanessa Coats
- School of Biology and Ecology, University of Maine, 5722 Deering Hall, Orono, ME 04469-5722, USA
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13
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Niemann J, Tisa LS. Nitric oxide and oxygen regulate truncated hemoglobin gene expression in Frankia strain CcI3. J Bacteriol 2008; 190:7864-7. [PMID: 18820019 PMCID: PMC2583611 DOI: 10.1128/jb.01100-08] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Accepted: 09/16/2008] [Indexed: 11/20/2022] Open
Abstract
The Frankia genome contains two truncated hemoglobin genes (hboN and hboO) whose functions remain to be determined. Nitric oxide (NO) generated by the addition of 400 microM SNAP (S-nitroso-N-acetylpenicillamine) caused a 10-fold increase in hboN gene expression but had no effect on hboO expression. The addition of the NO scavenger, carboxy-PT10, reduced the effect of SNAP. hboO gene expression increased under low-oxygen conditions, while hboN expression was unaffected. These results suggest that HboN may function in protection from nitrosative stress and that HboO may act as an oxygen transport molecule for increased respiration in hypoxic environments.
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Affiliation(s)
- James Niemann
- Department of Microbiology, University of New Hampshire, 46 College Rd., Durham, NH 03824-2617, USA
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14
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Pawlowski K, Jacobsen KR, Alloisio N, Ford Denison R, Klein M, Tjepkema JD, Winzer T, Sirrenberg A, Guan C, Berry AM. Truncated hemoglobins in actinorhizal nodules of Datisca glomerata. PLANT BIOLOGY (STUTTGART, GERMANY) 2007; 9:776-85. [PMID: 17682965 DOI: 10.1055/s-2007-965258] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Three types of hemoglobins exist in higher plants, symbiotic, non-symbiotic, and truncated hemoglobins. Symbiotic (class II) hemoglobins play a role in oxygen supply to intracellular nitrogen-fixing symbionts in legume root nodules, and in one case ( Parasponia Sp.), a non-symbiotic (class I) hemoglobin has been recruited for this function. Here we report the induction of a host gene, dgtrHB1, encoding a truncated hemoglobin in Frankia-induced nodules of the actinorhizal plant Datisca glomerata. Induction takes place specifically in cells infected by the microsymbiont, prior to the onset of bacterial nitrogen fixation. A bacterial gene (Frankia trHBO) encoding a truncated hemoglobin with O (2)-binding kinetics suitable for the facilitation of O (2) diffusion ( ) is also expressed in symbiosis. Nodule oximetry confirms the presence of a molecule that binds oxygen reversibly in D. glomerata nodules, but indicates a low overall hemoglobin concentration suggesting a local function. Frankia trHbO is likely to be responsible for this activity. The function of the D. glomerata truncated hemoglobin is unknown; a possible role in nitric oxide detoxification is suggested.
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Affiliation(s)
- K Pawlowski
- Department of Plant Biochemistry, Göttingen University, 37077 Göttingen, Germany.
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15
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Heckmann AB, Hebelstrup KH, Larsen K, Micaelo NM, Jensen EØ. A single hemoglobin gene in Myrica gale retains both symbiotic and non-symbiotic specificity. PLANT MOLECULAR BIOLOGY 2006; 61:769-79. [PMID: 16897491 DOI: 10.1007/s11103-006-0048-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Accepted: 03/19/2006] [Indexed: 05/10/2023]
Abstract
Here, a hemoglobin gene from the nitrogen-fixing actinorhizal plant Myrica gale was isolated, cloned and sequenced. The gene (MgHb) was a class I hemoglobin with strong sequence homology to non-symbiotic hemoglobin genes. MgHb is highly expressed in symbiotic root nodules, but transcripts and protein were also detected in leaves of M. gale. In Arabidopsis thaliana the MgHb promoter, linked to a beta-glucuronidase coding region, directed expression in the vascular tissue, in shoot meristem and at root branch point--a pattern very similar to the combined expression pattern of the two non-symbiotic A. thaliana hemoglobin promoters AHb1 and AHb2. The results points to a symbiotic as well as a non-symbiotic specificity of MgHb similar to a hemoglobin gene identified in Parasponia andersonii, but different from the situation in Casuarina glauca--a close actinorhizal relative of M. gale.
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Affiliation(s)
- Anne B Heckmann
- Department of Molecular biology, Laboratory of Gene Expression, University of Aarhus Gustav Wieds Vej, 10C DK-8000, Aarhus C, Denmark
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Lira-Ruan V, Sarath G, Klucas RV, Arredondo-Peter R. In silico analysis of a flavohemoglobin from Sinorhizobium meliloti strain 1021. Microbiol Res 2003; 158:215-27. [PMID: 14521231 DOI: 10.1078/0944-5013-00200] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hemoglobins (Hbs) have been characterized from a wide variety of eubacteria, but not from nitrogen-fixing rhizobia. Our search for Hb-like sequences in the Sinorhizobium meliloti genome revealed that a gene coding for a flavohemoglobin (fHb) exists in S. meliloti (SmfHb). Computer analysis showed that SmfHb and Alcaligenes eutrophus fHb are highly similar and could fold into the same tertiary structure. A FNR-like box was detected upstream of the smfhb gene and mapping analysis revealed that the smfhb gene is flanked by nos and fix genes. These observations suggest that smjhb is regulated by the concentration of O2 and that SmfHb functions in some aspects of nitrogen metabolism.
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Affiliation(s)
- Verónica Lira-Ruan
- Laboratorio de Biofísica y Biología Molecular, Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Avenida Universidad 1001, Colonia Chamilpa, 62210 Cuernavaca, Morelos, México
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Abstract
Globins are an ancient and diverse superfamily of proteins. The globins of microorganisms were relatively ignored for many decades after their discovery by Warburg in the 1930s and rediscovery by Keilin in the 1950s. The relatively recent focus on them has been fuelled by recognition of their structural diversity and fine-tuning to fulfill (probably) discrete functions but particularly by the finding that a major role of certain globins is in protection from the stresses caused by exposure to nitric oxide (NO)--itself a molecule that has attracted intense curiosity recently. At least three classes of microbial globin are recognised, all having features of the classical globin protein fold. The first class is typified by the myoglobin-like haemprotein Vgb from the bacterium Vitreoscilla, which has attracted considerable attention because of its ability to improve growth and metabolism for biotechnological gain in a variety of host cells, even though its physiological function is not fully understood. The truncated globins are widely distributed in bacteria, microbial eukaryotes as well as plants and are characterised by being 20-40 residues shorter than Vgb. The polypeptide is folded into a two-over-two helical structure while retaining the essential features of the globin superfamily. Roles in oxygen and NO metabolism have been proposed. The third and best understood class comprises the flavohaemoglobins, which were first discovered and partly characterised in yeast. These are distinguished by the presence of an additional domain with binding sites for FAD and NAD(P)H. Widely distributed in bacteria, these proteins undoubtedly confer protection from NO and nitrosative stresses, probably by direct consumption of NO. However, a bewildering array of enzymatic capabilities and the presence of an active site in the haem pocket reminiscent of peroxidases hint at other functions. A full understanding of microbial globins promises advances in controlling the interactions of pathogenic bacteria with their animal and plant hosts, and manipulations of microbial oxygen transfer with biotechnological applications.
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Affiliation(s)
- Guanghui Wu
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN, England, UK
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Beckwith J, Tjepkema JD, Cashon RE, Schwintzer CR, Tisa LS. Hemoglobin in five genetically diverse Frankia strains. Can J Microbiol 2002; 48:1048-55. [PMID: 12619816 DOI: 10.1139/w02-106] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Five strains of Frankia were selected to represent a wide range of genetic diversity and examined for presence of hemoglobin. All five strains produced hemoglobin when grown on media without (-N) or with (+N) combined nitrogen. This indicates that hemoglobin is common in Frankia and is not directly associated with nitrogen fixation. Frankia strain EAN1(pec) was examined in more detail. It showed greater hemoglobin concentration when grown at 2% O2 than at 20% O2 in the -N treatment but no effect of oxygen on hemoglobin concentration in the +N treatment. At both oxygen levels, it produced substantially more biomass in +N than in -N culture. It also produced significantly more biomass when the medium contained 0.2% CO2 than in the absence of CO2. The molecular mass of the hemoglobin as determined by size exclusion chromatography was 13.4 +/- 0.2 kDa (mean +/- SE, n = 3) and is consistent with that of a truncated hemoglobin. The hemoglobin had absorption spectra that were typical of a hemoglobin. The oxygen dissociation rate constants for the hemoglobin were 131.2 +/- 5.8 s(-1) for -N culture and 166 +/- 8.2 s(-1) for +N culture. These rapid rates are consistent with a function in facilitated diffusion of oxygen.
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Affiliation(s)
- Jason Beckwith
- Department of Biological Sciences, University of Maine, 5722 Deering Hall, Orono, ME 04469-5722, USA
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