Expression Of Symbiotic And Nonsymbiotic Globin Genes Responding To The Microsymbionts Infection On Lotus Japontcus

Tsuruta1, Y. Mukoyoshi1, A. Suzuki1, S. Sato2, K. Senoo3, 1 Dept of Chemistry and Bioscience, Kagoshima University, Kagoshima 890-0065, Japan 2Kazusa DNA Research Institute, Chiba 292-0812, Japan 3Dept of Sustainable Resource Science, Mie University, Mie 514-8507, Japan All plants are expected to have hemoglobins nodule specific globins are called 'symbiotic globins' and globins not involved in symbiosis with rhizobia and Frankia are called 'nonsymbiotic globins'....

Results and Discussion

Sequencing the rhizobial DNA flanking the minitransposon insertions revealed that genes required for cytochrome biosynthesis, DNA modification, lipid metabolism, membrane transport, and regulation were transcriptionally activated by low pH. Other insertions disrupted membrane proteins of unknown function. To detect low pH-inducible proteins possibly essential for growth under acidic conditions, we compared protein profiles of cells exposed to a persistent or transient acid-stress. We found...

Response Of Legume Roots To Hog Gastric Mucin Blood Group Ah Substance A Carbohydrate Ligand For Legume Root

Calif., Davis, CA, USA Previous studies from this laboratory established that Db-LNP, a lectin nucleotide phosphohydrolase present in the roots of the legume, Dolichos biflorus, is a Nod factor-binding protein present on the surface of root hair and epidermal cells in the nodulation zone of roots and that this protein most probably plays a role in the initiation of the rhizobium-legume symbiosis. This LNP is isolated from roots by affinity chromatography on hog...

Chairs Comments The Nitrogen Cycle

Ingendahl, E. ter Haseborg, H. Kreibich, P. Vinuesa Fachgebiet Zellbiologie und Angewandte Botanik, Fachbereich Biologie der Philipps-Universitaet, D-35032 Marburg, Germany In contrast to general belief, the largest nitrogen pool on our planet is not in the atmosphere (4 x 1015 tons) but in the primary rocks (1.9 x 1017 tons). Compared to these pools, the N2 dissolved in the sea is only around 2.2 x 1013 tons. The other nitrogen pools (of nitrate, ammonia, organic nitrogen in the...

Acknowledgements

This work was carried with funding from Department of Biotechnology, Government of India. FUNCTIONAL CHARACTERIZATION OF NODULIN 26 AND GAMMA TIP ORTHOLOGS FROM THE NODULES OF LOTUS JAPONICUS Dept Biochem. Cell. Molecular. Biol., Univ. of Tennessee, Knoxville, TN 37996, USA During the establishment of rhizobia legume symbioses a subset of nodulins are targeted to the symbiosome membrane that encloses the rhizobia bacteroid. Among these proteins is nodulin 26 (Fortin et al. 1987), which...

The Quest for the FixJ Regulon

In the regulatory cascade controlling nif and fix genes, FixJ is a global regulator, while nif A and fixK are specialized regulators of nif and fix genes, respectively. This regulatory network architecture suggested that FixJ might control yet other sets of genes in response to microaerobiosis in the nodule environment. Figure 3. Distribution of FixJ binding sites on the S. meliloti genome. Figure 3. Distribution of FixJ binding sites on the S. meliloti genome. In order to identify potential...

Studies On The Interaction Between Pn AND NifA In Azospirillumbrasilense By Using A Yeast Twohybrid System

Dept of Microbiology, China Agricultural University, Beijing 100094, China Pn is specifically required for nitrogen fixation in A. brasilense. Pn activates NifA, preventing an inhibitory effect on the N-terminal domain (Arsene et al. 1996). However, the mechanism of Pn interacting with NifA directly or indirectly is unknown. Here we investigate the interaction between Pn and NifA in A. brasilense Sp7 by using yeast two-hybrid system. The glnB gene encoding Pn was PCR amplified and fused to the...

Regulation of the Nitrogenase Activity

Two mechanisms for the regulation of the nitrogenase Fe-protein activity have been described in Rhodobacter capsulatus. One involves the classical ADP-ribosylation process, whereas the second one is independent of ADP-ribosylation (Yakunin, Hallenbeck 1998). R. capsulatus contains two nifA genes and one an A (see Masepohl et al. this volume). In this bacterium, a double glnB-glnK mutant escapes ammonia control both at the level of the synthesis of nitrogenase and the regulation of its activity....

Regulation Of The Bradyrhizobium Japonicum sdh Operon Encoding Succinate Dehydrogenase

Department of Biological Sciences, University of Missouri - Rolla, MO, USA Succinate is one of the primary carbon and energy sources within the nitrogen-fixing nodule. The rhizobia depend on energy from these plant-supplied substrates for nitrogen fixation. Succinate is oxidized by succinate dehydrogenase (Sdh) which participates directly in the electron transport chain. A critical role for Sdh in nitrogen fixation is supported by a R. meliloti strain lacking succinate dehydrogenase activity...

Materials and Methods

Bacterial strains used Azospirillum brasilense strains FP2, Sp7, Cd and 245 A. lipoferum Sp59 and JA25 A. amazonense strains Y2 and Y6 A. irakense and A. halopraeferens. Media and growth conditions strains of A. lipoferum, A. brasilense, A. iraquense and A. halopraeferens were grown in NFb medium and the strains of A. amazonense in LGI medium. Pulsed-field gel electrophoresis (PFGE) of chromosomal DNA was done using a Gene Navigator pulsed-field system (Pharmacia). The chromosomes of S....

Introduction

Nitrogenase switch-off by ADP ribosylation in some diazotrophs is due to the inactivation of the Fe-protein (Lowery 1986) by the transfer of an ADP-ribosyl residue to one of the subunits, catalyzed by dinitrogenase reductase ADP-ribosyl transferase (DRAT), and the activity is recovered by dinitrogenase reductase-activating glycohydrolase (DRAG) (Lowery 1986). ntrC mutants of A. brasilense were impaired in nitrogenase switch-off (Pedrosa, Yates 1984) suggesting that NtrC may participate in a...

Colony Structure Protects Nitrogenase From 02 Inactivation In The Sugarcane Endophyte Gluconacetobacter Diazotrophicus

Vessey2, M.J. Canny3, M.E. McCully3, B. Luit2, B. Pan2, R.S. Faustino4, G.N. Pierce4 'Dept of Biology, St. Mary's University, Halifax, NS, Canada 2Dept of Plant Science, Univ. Manitoba, Winnipeg, MB Canada 3Division of Plant Industry, CSIRO, Canberra, ACT 2601, Australia 4Dept of Physiology, Univ. Manitoba, Winnipeg, MB, R3E 3J7

Role of Polysaccharides in the Infection Process

To invade nodules through infection threads, Sinorhizobium meliloti must synthesize at least one of the following polysaccharides succinoglycan, EPS II or a symbiotically active form of K-antigen (Figure 1). Mutants defective in the production of these polysaccharides are blocked at the nodule invasion step and induce the formation of small white root nodules devoid of bacteria (Leigh 1985 Reuber et al. 1991 Gonzalez et al. 1996). Many studies have utilized strains, Rml021 and Rm2011, which...

Conclusion About Nitrogen Fixation

Biological nitrogen fixation can supply the N demand of important crops grown in South America, such as soybean and common bean. Soybean is an exotic plant in Brazil and therefore soybean bradyrhizobia diversity is restricted to changes caused by adaptation of inoculant strains to the soil. Some fast-growing indigenous strains are also able to nodulate soybean and were identified mainly as R. tropici, but are poor competitors against Bradyrhizobium. On the other hand, a high level of diversity...

Rapid And Reversible Nitrate Inhibition On Nodule Growth And N2 Fixation In Soybean

Suganuma1, T. Sato2, N. Ohtake1, K. Sueyoshi1, T. Ohyama1 'Faculty of Agriculture, Niigata University, Niigata 950-2181, Japan 2Faculty of Bioresource Sciences, Akita Pref. University, Akita 010-0195, Japan In soybean plants, the development and function of root nodules are markedly depressed when the nodulated roots are in direct contact with a high level of NO3 a main form of inorganic nitrogen in field. A short-term effect of presence or absence of 5 mM NO3 in...

Ferritin And Iron Management In Legume Plant Development And Nodulation

Kolaczkowska-Szczesniak, E. Sobieszczuk, A.B. Legocki Institute of Bioorganie Chemistry Polish Academy of Sciences, Noskowskiego 12 14, Pozna 61-704, Poland Iron is one of the most important nutrients for all eukaryotes. However, it is also one of the most dangerous elements. Because of its redox properties, iron is a critical element for such basic processes as DNA and hormone synthesis, respiration and photosynthesis (Briat et al. 1995). Although iron is the...

References

Microbiol. 36, 508-515 Atkins CA, Smith PMC (2000) In Triplett E (ed), Prokaryotic Nitrogen Fixation, pp. 559-587, Horizon Scientific Press, Wymondham, UK Day DA et al (2001) Cell. Mol. Life Sci. 58, 61-71 Li Y et al (2001) Microbiol. 147, 663-670 Waters JK et al (1998) Proc. Nat. Acad. Sci. USA 95, 12038-12042 Section 11 Endophytic Associative Plant-Microbe Interactions CHAIR'S COMMENTS ENDOPHYTIC AND ASSOCIATIVE PLANT-MICROBE INTERACTIONS Dept Plant Pathology,...

Genospecies In Bradyrhizobium In Search Of Phenotypic Differentiation

Laboratory of Microbiology, Dept of Biochemistry, Physiology & Microbiology, University of Gent, K.L. Ledeganckstraat 35, B-9000 Gent, Belgium Bradyrhizobium contains three named species (B. japonicum, B. elkanii, B. liaoningense) and a number of unnamed groups from various host plants. Genospecies I-XI (Willems et al. 2001a, 2001b) were revealed by DNA DNA hybridization and genospecies I-VII confirmed by sequence analysis of the internal transcribed spacer (ITS) between the 16S and 23S rRNA...

Plant Growth Promotion in H2Treated Soils

Since evolution and crop breeding programs have not favored HUP+ symbioses over HUP symbioses, it may be possible that H2 evolution by nodules is beneficial to the growth and yield of the symbiosis. To test this hypothesis, plant growth was compared in soils that were previously exposed to air or to H2 in air at an H2 exposure rate that increased from 63 to 250 pinoles L1 soil h1 over a 9 week period. This H2 exposure rate was similar to that experienced by soils adjacent to legume nodules...

Soybean UreD and UreF Looking for a Locus

UreD, UreF and UreG were annotated by the S. pombe genome project We exploited UreD and UreF as (i) heterologous probes to recover the soybean cDNA homologs, and (ii) a source of PCR primers to confirm their presence in genomic DNA clones (generously provided by Dr N. Honey, Massey Univ., NZ) complementing urease mutants of S. pombe (Kinghorn, Fluri 1984). We are now attempting to correct S. pombe mutants, identified as ureD, ureF and ureG, with the soybean orthologs. RT PCR analysis of an eu2...

Lotus Japonicus Functional Genomics cDna Micro Array Analysis Uncovers Novel Nodulins

Essigmann1, G. Colebatch1, S. Kloska1, P. Smith2, B. Trevaskis1 'Max Planck Institute of Molecular Plant Physiology, Am Mithlenberg 1, 14476 Golm, 2Dept Botany, Univ. of West. Aust., Crawley, WA 6009, Australia 1. Introduction Functional genomics brings together high-throughput genetics with multi-parallel analyses of gene transcripts, proteins, and metabolites to answer the ultimate question posed by all genome-sequencing projects What is the biological function of...

Genomics Tools For Dissecting Nodulation In The Model Legume Medicago Truncatula

'Department of Plant Biology, 220 BioSci Center, 1445 Gortner Ave, University of Minnesota, St. Paul, MN, 55108, USA department of Plant Pathology, Room 254 Hutchinson Hall, University of California, Davis, CA 95616, USA Approximately ten years after the elucidation of Nod factor, the lipochito-oligosaccharide made by rhizobia in response to their host plants, investigators have identified many responses to this signal in plant roots. In addition, many details of cellular function in infected...

Role Of Arginine In Root Nodule Nitrogen Metabolism Of Datisca Glomerata

Pawlowski3, P.A. Okubara4, K.R. Jacobsen5 *Dept Environmental Horticulture, U Calif, Davis, CA, USA 2Sect Plant Biology, U Calif, Davis, CA, USA Albrecht v. Haller Inst, Univ Goettingen, Germany 4USDA-ARS, Wash St U, Pullman, WA, USA, 5Dept Agronomy, U Calif, Davis, CA, USA In root nodules of the actinorhizal host Datisca glomerata, glutamine synthetase (GS) is expressed at high levels in uninfected tissue, but not in infected tissue, as shown by in situ...

Main Limiting Factors of BNF in Tropics

Although inoculation with efficient and competitive strains can increase grain yield of soybean, common bean and other legumes in Brazil some limiting factors to the biological process are often reported under field conditions. High temperature and low soil moisture are major causes of nodulation failure, affecting all stages of the symbiosis and limiting rhizobial growth and survival in soil. They may also contribute to undesirable changes in rhizobia, including plasmid deletions, genomic...

Application Of Tree Legume Rhizobia For Reforestation Program In Thailand Ii Biodiversity Of Tree Legume Rhizobia In

Kotepong2, A. Nuntagij2, N. Boonkerd1 1 School of Biotechnology, Suranaree University of Technology, Nakhon Ratchasima, Thailand 2Soil Microbiology Research Group, Division of Soil Science, Department of Agriculture, Thailand Rhizobial strains from tree legumes were isolated from five varieties of native tree leguminous plants in all parts of Thailand, altogether with selected the highest N2-fixing efficiency strains. The 17 strains were isolated from Acacia...

Isolated FeMoCo Catalytic Reactivity In Nonprotein Surrounding Substrate And Inhibitor Interactions C2H2 N2 CO

Petrova Inst, of Problems of Chem. Phys., Russ. Acad. Sci., 142432, Chernogolovka, Russia To understand the mechanism of substrate reduction in the active site of nitrogenase the catalytic reactivity of the isolated FeMo-co with respect to C2H2, and or CO, and or N2 reduction in non-enzymatic surroundings (DMF, Eu Hg, PhSH) was investigated. The quality of the FeMo-co extracted (before and after catalytic reactions) was evaluated from its Fe Mo ratio and its...

Alfalfa Root Nodules and ROS

On the other hand, alfalfa responds to infection with Sinorhizobium meliloti by production of O2 and H2O2. O2 was detected in infection threads and in infected cells in nodules up to nine days old. H2O2 production was seen in walls and infection threads of infected cells (zone II). H2O2 was not found in the meristematic zone I and fixation zone III (Santos et al. 2001). Thus, alfalfa produces a prolonged oxidative burst in response to S. meliloti infection. This is reminiscent of the oxidative...

Characterization Of Defense Responses Of Sesbania Rostrata

Sam2, S. Satoshi1, M. Hiroki1, M. Yukihiro1, H. Marcelle2, 'Dept Global Agri. Sci., U. Tokyo, Tokyo, Japan 2Dept Plantengenetica, VIB, U. Gent, Gent, Belgium Sesbania rostrata is an annual, fast-growing legume from the Sahel region of West Africa and parts of Angora, Mozambique and Madagascar with tropical climates and flooded soils, where it engages in symbiotic nitrogen fixation with Azorhizobium caulinodans. Nitrogen-fixing nodules are formed at lateral root...

Nitrogen Fixation Genes and Electron Transfer

Two clusters containing nitrogen fixation genes have been cloned. The general organization is very similar to that of Azotobacter vinelandii. A cluster carries nitrogenase structural genes (nifHDK), nijTY and nifNE (AJ313205). A second cluster carries nifLA and nifBQ (AJ307878). nifA is located 7 kb upstream of nifB. Inactivation of nifA, nifB, nifH and nifE led to a Nif negative phenotype while a nifY mutant remained Nif' . A second copy of nifY was found upstream of nifH as well as a set of...

Global Perspectives

Proceedings of the 13 International Congress on Nitrogen Fixation Hamilton, Ontario, Canada 2-7 July 2001 Turlough M. Finan, Mark R. O'Brian, David B. Layzell, J. Kevin Vessey and William Newton CABI Publishing is a division of CAB International CABI Publishing CAB International Wallingford CABI Publishing 10 E 40th Street Suite 3203 New York, NY 10016 USA Tel +44(0)1491 832111 Fax +44(0)1491 833508 Email cabi cabi.org Tel +1 212 481 7018 Fax +1 212 686 7993 CAB International 2002. All rights...

Large Scale Genome Analysis Of Lotus Japonicus Mg20

Kato, E. Asamizu, S. Tabata Kazusa DNA Research Institute, 1532-3 Yana, Kisarazu, Chiba 292-0812, Japan The progress in DNA sequencing technology has allowed us to perform systematic and comprehensive analysis of genetic information in a variety of organisms. The entire genomes of several higher eukaryotes including a flowering plant, Arahidopsis thaliana, have already been sequenced, and the complete lists of potential gene complements in its genome have...

Material and Methods

Bradyrhizobium japonicum 110spc4 is a spontaneous spectinomycin resistant mutant of USDA3Ibll0 and is referred to as wild type (wt) in this work. A136 is a mutant derivative of 110spc4 (Figure 1). Strain 149 has a uidA gene integrated into the chromosome downstream of the nod box promoter preceding tts A (Figure 1). For expression analyses, B. japonicum was grown in YEM medium to the stationary phase. Cells were resuspended in the same amount of fresh medium and genistein was added to a...

Endoreduplication Is Essential For Symbiotic Cell Differentiation In Medic Ago Truncatula

Fedorova, A. Cebolla, F. Roudier, S. Tarayre, G. Horvath, Institut des Sciences du Vegetal, CNRS UPR 2355, 91198 Gif sur Yvette, France 1. Introduction Plant organ development is a constant interplay between cell cycle and differentiation programs. Various stages of nodule development are controlled by differential regulation of the cell cycle. As a first step, the rhizobial Nod factors activate the cell cycle in the nodulation sensitive root zone. In Medicago...

Pl theoretical

Diagramatic representation of S. meliloti proteins capable of being analyzed by proteome analysis. The dots represent the theoretical pi and molecular weight of proteins predicted from the S. meliloti chromosome. The box represents the pi and molecular mass window that is capable of being examined by 2-DGE analysis. The procedures used to resolve, stain and quantify proteins in a gel are influenced by the experimental aims and by the type of post-gel analysis employed. Some of the...

Johanna Dbereiner Fifty Years Dedicated To The Biological Nitrogen Fixation Research Area

Reis Embrapa Agrobiolog a, BR465, Km47, 23851-970-Serop dica, Rio de Janeiro, Brazil Johanna D bereiner was born in the former Czechoslovakia in 1924, immigrated to Brazil in 1950 and became a Brazilian citizen by option in 1956. She was an extremely enthusiastic person in the field of Biological Nitrogen Fixation (BNF) which began, almost incidentally, when she was employed by the Research Department of the Brazilian Ministry of Agriculture (nowadays Embrapa)...

Identification Of Indole3butyric Acid In Azospirillum Cultures

S nchez Ahedo 'Microbiological Research Center, University Autonomous of Puebla, Puebla, Pue. M xico 2Mexican Institute of Petroleum, M xico D.F. M xico Azospirillum is a metabolically versatile organism with the ability to associate with the agronomically important plants it produces several metabolites involved in beneficial effects to the plants for instance, for the production of phytohormones by the microorganism there is more than one pathway for the synthesis...

Importance of Urea Urease and Ni to Plants

Most or all plants have ureolytic activity (Hogan et al. 1982). To produce it they must deal with potentially toxic nickel (Ni), essential for an active urease. There are no other known plant Ni metalloenzymes (Gerend s et al. 1999) as opposed to six (urease, hydrogenase, CO dehydrogenase, methyl-CoM reductase, acetyl-CoA synthase and a superoxide dismutase) in bacteria (Ragsdale 1998). EST databases and mutational analysis of urease expression in soybean indicate that plants have specific...

Phytological Aspects Of Heavy Metal Toxicty In Clover Trifolium Alexandrinum

El-Toukhy, K.I.R. Badawy Bot. Dep. Women's College Ain Shams Univ., Heliopolis, Cairo, Egypt Pollution Unit, Desert Research Center (DRC), Cairo, Egypt Studies were conducted to present evidence that nodulation, biomass, chlorophyll and metal content of a forage legume (clover) may serve for ecotoxicological evaluation of contaminated areas. Substances affecting the macro- and or microsymbionts, such as certain heavy metals were examined. The experiments were carried out...

Plants for Biological N Fixation

The main grain legumes in industrialized countries include soybean (Glycine max L.), pea (Pisum sativa L.), lentil (Lens culinaris Medikus), lupin and bean (Phaseolus spp.). The area dedicated to grain legume production has increased dramatically in the past 20 years. Some of the more dramatic examples include lupin production in western Australia (117,939 ha in 1980 2,042,000 ha in 2000) and dry pea production in western Canada (49,300 ha in 1980 1,219,000 ha in 2000)...

Ammonia Oxidation Pathway

The oxidation of NH3 to NO2 is carried out in two steps (Figure 1) (Hooper, 1989). NH3 is first oxidized to hydroxylamine (NH2OH) by ammonia monooxygenase (AMO). NH2OH is subsequently oxidized to NO2 by hydroxylamine oxidoreductase (HAO). In the reaction catalyzed by AMO, one O from O2 is inserted into NH3 while the second O is reduced to H2O. This reaction requires two additional electrons. Because NH3 is the only source of reductant for these bacteria, the electrons required for the formation...

Essential Genes actA

Mutations in this gene result in an inability to grow at pH 6 or to maintain intracellular pH (pH ) if the external pH (pHe) is less than 6.5 (O'Hara et al. 1989). The mutant (TG2-6) is also abnormally copper- and zinc-sensitive at pH 7.0, but removal of copper from the medium does not restore acid-sensitivity. Complementation resulting in restoration of acid tolerance also restores copper- and zinc-tolerance (Tiwari et al. 1996a). The deduced ActA protein sequence is suggestive of a membrane...

Signal Exchange During The Early Events Of Soybean Nodulation

Nod Genes Bradyrhizobium

Lee, C. Bickley, D. Lohar, G. Liao, G. Copley, Center for Legume Research, Department of Microbiology, University of Tennessee, Knoxville, TN, 37996-0845, USA 1. Regulation of the Bradyrhizobium japonicum Nodulation Genes The regulation of nod gene expression in several (Sino)Rhizobium Bradyrhizobium Azorhizobium species has been extensively studied. Current evidence shows that most nod genes are involved in the production of substituted lipo-chitin Nod...

Knockout Of An Azorhizobial dTdplrhamnose Synthase Affects Lipo And Exopolysaccharide Synthesis And Symbiosis With

De Rycke, M. Holsters Dept of Plant Genetics, V.I.B., K.L. Ledeganckstraat 35, B-9000 Gent, Belgium The micro-symbiont, Azorhizobium caulinodans ORS571, induces nitrogen-fixing nodules on both stem and roots of the tropical leguminous host plant, Sesbania rostrata. Besides azorhizobial lipochito-oligosaccharidic Nod factors (D'Haeze et al. 1998), surface polysaccharides (SPSs), comprising lipo- (LPSs), capsular (CPSs), and exopolysaccharides (EPSs), play a...

Alanine Synthesis And Secretion By Rhizobium Leguminosarum

Allaway, A. Bordes Division of Microbiology, School of AMS, University of Reading, Whiteknights, Reading, RG6 6AJ, UK On the basis of 15N-labeling studies it had been generally accepted that ammonium is the sole secretion product of N2-fixation by the bacteroid and that the plant is responsible for assimilating it into amino acids. However, 15N-labeling studies indicated that soybean bacteroids only secrete alanine and not ammonia (Waters et al. 1998). We...

The Organization of the nif Operon

A DNA region containing putative nif genes and belonging to the endosymbiont Burkholderia has been identified and characterized (Minerdi et al. 2001). Screening of the library with Azospirillum brasilense nifHDK genes as the prokaryotic probes led to the identification of a 6413 bp region. Analysis revealed three open reading frames (ORFs) encoding putative proteins with a very high degree of sequence similarity with the two subunits (NifD and NifK) of the component I and with component II...

Application Of Tree Legume Rhizobia For Reforestation Programme In Thailand I Selection And Management Of Rhizobia For

Jitacksorn , N. Teaumroong , N. Boonkerd 'Soil Microbiology Research Group, Division of Soil Science, Department of Agriculture, Bangkok, Thailand 2School of Biotechnology, Suranaree University of Technology, Nakhon Ratchasima, Thailand Leguminous trees such as Acacia, Pterocartpus, and Leuceana have been recommended for reforesting in denuded and degraded lands in Thailand. These leguminous trees successfully compete with native grasses and adapted to adverse...

Construction Of A Microarray Covering The Sinorhizobium Meliloti1021 Genome

Weidner1, U.D. Schiller2, S. Kurtz2, R. Giegerich2, Lehrstuhl fur Genetik, Universit t Bielefeld, Germany 2AG Praktische Informatik, Technische Fakult t, Bielefeld, Germany Sequencing of the genome of the symbiotic soil bacterium S. meliloti 1021 was recently finished by an international consortium (Galibert et al. 2001). The genome consists of three replicons the 3.5 Mb chromosome, the 1.35 Mb megaplasmid pSymA and the 1.7 Mb megaplasmid pSymB. Annotation of...

Biofixation And Nitrogen In The Biosphere And In Global Food Production

Department of Geography, University of Manitoba, Winnipeg, MB, R3T 2N2 Canada Meetings such as this one are triumphs of scientific reductionism. In this room, we have dozens of people who know more about some extremely specialized attribute of biofixation or bacterial and plant physiology than does anybody else on this planet of more than six billion people. As a counterweight to this restrictive attention, and following the tradition of keynote addresses (including some given at these biannual...

Response Of The Coffee Plant To The Inoculation With Azospirillum Sp

V zquez-Ch vez, A. Tapia-Hern ndez, M.A. Mascar a-Esparza, M. Rosas-Morales, L.E. Fuentes-Ram rez Centro de Investigaciones en Ciencias Microbiol gicas, Instituto de Ciencias, Universidad Aut noma de Puebla, Apdo. Postal 1622, CP 72000, Puebla, Pue., M xico The coffee plant is a crop that is cultivated in large areas of the tropics. It produces one of the greatest incomes of the non-developed countries. Competitive production of grain demands the application of large...

Endophytic Bacteria In Induced Root Nodules On Eggplant And Tomato

G-Laboratory, Beijing Liuhe Newstar Biological Technology Co. Ltd. Through optical microscopes, transmitting electron microscopes and scanning electron microscopes, the ultrastructure of and endophytic bacteria in artificially-induced nodules on the roots of eggplant (Solarium melongena L.) and tomato (Lycopersicon esculentum Mill.), plants were observed and studied. The results show that a large number of nodules formed on the root system due to intrusion of autogenous azotobacters. Within the...

Chairs Comments Biological Nitrogen Fixation And Sustainable Agriculture

Biol., Cuernavaca, Morelos, M xico Nitrogen is the major limiting nutrient for most crop species. The acquisition and assimilation of nitrogen for plant growth and development is second in importance only to photosynthesis (Vance 1997). Biological nitrogen fixation constitutes the main natural input of nitrogen into the biosphere. This represents around 50 of the total fixed nitrogen, the other half is fixed through chemical processes. The chemical reduction...

Lipochitooligosaccharides and Controls on Crop Production

The chitin backbone of the LCO may cause it to act, in some way, like an elicitor in disease systems. LCO reduces salicylic acid levels in alfalfa roots, potentially aiding in suppression of legume host defense responses, and thereby ensuring successful infection (Martinez-Abarca et al. 1998). More recently, we have shown that a strong reduction in SA level in the leaf tissues occurred when soybean plants were sprayed with LCO (Prithiviraj et al. 2000b). Nod factors can alter phytoalexin...

Nitrogen Fixation Analysis Of The Genome Of The Cyanobacterium Nostoc Punctiforme

Elhai3, M. Potts4, F. Larimer5, J. Lamerdin6, P. Predki7, R. Atlas8 department of Biology, University of Missouri, St. Louis, MO 63121, USA 2Section of Microbiology, University of California, Davis, CA 95616, USA department of Biology, University of Richmond, Richmond, VA 23173, USA department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg,VA 24061, USA Computational Biology, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA...

Expression Of The Direct Glucose Oxidative Pathway In Acetobacter Diazotrophicus

Boiardi CINDEFI, Facultad de Cs. Exactas UNLP -CONICET, Argentina A. diazotrophicus oxidizes glucose extracellularly to gluconate via a PQQ-linked glucose dehydrogenase GDH . This is considered the main route for glucose catabolism in this bacterium. Moreover, aldose oxidation through GDH allows N2-fixing A. diazotrophicus to direct the electron flux through a more efficient branch of its respiratory chain generating extra utilizable energy Luna et al. 2000 ....

Isolation And Characterization Of Diazotrophic Endophytes From Grasses And Their Effects On Plant Growth

Nitrogen Fixation Plants

Chelius, Y. Dong, A.L. Iniguez, S.M. Kaeppler, Dept of Agronomy, University of Wisconsin-Madison, Madison, WI 53706, USA 1. Introduction The discovery of nitrogen fixation by diazotrophic endophytes in sugarcane by Dobereiner, Kennedy and coworkers for reviews see Boddey et al. 2000 Sevilla, Kennedy 2000 has encouraged several laboratories around the world to identify nitrogen-fixing associations between other grasses and bacteria. Here, we review our efforts to...

Dna Binding Properties Of RepA A Protein Involved In Partition And Autoregulation Of The Replicator Region Of The

Ram rez-Romero, M.A. Cevallos Centro de Investigaci n sobre Fijaci n de Nitr geno, A. P. A.P. 565-A., UNAM Cuernavaca, Morelos, M xico As a member of the repABC plasmid family, the replicator region of the R. etli symbiotic plasmid, contains three genes repA, repB and repC and a conserved region sequence between repB and repC Ram rez-Romero et al. 1997 . A genetic analysis of the repABC genes showed that they are organized in an operon. The repA and repB genes encode...