WorldWideScience

Sample records for legume root-nodule symbiosis

  1. Nonlegumes, legumes, and root nodules harbor different arbuscular mycorrhizal fungal communities.

    NARCIS (Netherlands)

    Scheublin, T.R.; Ridgway, K.P.; Young, J.P.W.; van der Heijden, M.G.A.

    2004-01-01

    Legumes are an important plant functional group since they can form a tripartite symbiosis with nitrogen-fixing Rhizobium bacteria and phosphorus-acquiring arbuscular mycorrhizal fungi (AMF). However, not much is known about AMF community composition in legumes and their root nodules. In this study,

  2. NrcR, a New Transcriptional Regulator of Rhizobium tropici CIAT 899 Involved in the Legume Root-Nodule Symbiosis

    Science.gov (United States)

    del Cerro, Pablo; Rolla-Santos, Amanda A. P.; Valderrama-Fernández, Rocío; Gil-Serrano, Antonio; Bellogín, Ramón A.; Gomes, Douglas Fabiano; Pérez-Montaño, Francisco; Megías, Manuel; Hungría, Mariangela; Ollero, Francisco Javier

    2016-01-01

    The establishment of nitrogen-fixing rhizobium-legume symbioses requires a highly complex cascade of events. In this molecular dialogue the bacterial NodD transcriptional regulators in conjunction with plant inducers, mostly flavonoids, are responsible for the biosynthesis and secretion of Nod factors which are key molecules for successful nodulation. Other transcriptional regulators related to the symbiotic process have been identified in rhizobial genomes, including negative regulators such as NolR. Rhizobium tropici CIAT 899 is an important symbiont of common bean (Phaseolus vulgaris L.), and its genome encompasses intriguing features such as five copies of nodD genes, as well as other possible transcriptional regulators including the NolR protein. Here we describe and characterize a new regulatory gene located in the non-symbiotic plasmid pRtrCIAT899c, that shows homology (46% identity) with the nolR gene located in the chromosome of CIAT 899. The mutation of this gene, named nrcR (nolR-like plasmid c Regulator), enhanced motility and exopolysaccharide production in comparison to the wild-type strain. Interestingly, the number and decoration of Nod Factors produced by this mutant were higher than those detected in the wild-type strain, especially under salinity stress. The nrcR mutant showed delayed nodulation and reduced competitiveness with P. vulgaris, and reduction in nodule number and shoot dry weight in both P. vulgaris and Leucaena leucocephala. Moreover, the mutant exhibited reduced capacity to induce the nodC gene in comparison to the wild-type CIAT 899. The finding of a new nod-gene regulator located in a non-symbiotic plasmid may reveal the existence of even more complex mechanisms of regulation of nodulation genes in R. tropici CIAT 899 that may be applicable to other rhizobial species. PMID:27096734

  3. Production and Metabolism of Indole Acetic Acid in Root Nodules and Symbiont (Rhizobium undicola Isolated from Root Nodule of Aquatic Medicinal Legume Neptunia oleracea Lour.

    Directory of Open Access Journals (Sweden)

    Pallab Kumar Ghosh

    2015-01-01

    Full Text Available Indole acetic acid is a phytohormone which plays a vital role in plant growth and development. The purpose of this study was to shed some light on the production of IAA in roots, nodules, and symbionts of an aquatic legume Neptunia oleracea and its possible role in nodular symbiosis. The symbiont (N37 was isolated from nodules of this plant and identified as Rhizobium undicola based on biochemical characteristics, 16S rDNA sequence homology, and DNA-DNA hybridization results. The root nodules were found to contain more IAA and tryptophan than root; however, no detectable amount of IAA was found in root. The IAA metabolizing enzymes IAA oxidase, IAA peroxidase (E.C.1.11.1.7, and polyphenol oxidase (E.C.1.14.18.1 were higher in root than nodule but total phenol and IAA content were reversed. The strain N37 was found to produce copious amount of IAA in YEM broth medium with tryptophan and reached its stationary phase at 20 h. An enrichment of the medium with mannitol, ammonium sulphate, B12, and 4-hydroxybenzaldehyde was found to promote the IAA production. The presence of IAA metabolizing enzymes and IAA production with PGPR traits including ACC deaminase activity of the symbionts was essential for plant microbe interaction and nodule function.

  4. Quantitative modelling of legume root nodule primordium induction by a diffusive signal of epidermal origin that inhibits auxin efflux

    NARCIS (Netherlands)

    Deinum, Eva E.; Kohlen, Wouter; Geurts, René

    2016-01-01

    Background: Rhizobium nitrogen fixation in legumes takes place in specialized organs called root nodules. The initiation of these symbiotic organs has two important components. First, symbiotic rhizobium bacteria are recognized at the epidermis through specific bacterially secreted

  5. Phenolphthalein false-positive reactions from legume root nodules.

    Science.gov (United States)

    Petersen, Daniel; Kovacs, Frank

    2014-03-01

    Presumptive tests for blood play a critical role in the examination of physical evidence and in the determination of subsequent analysis. The catalytic power of hemoglobin allows colorimetric reactions employing phenolphthalein (Kastle-Meyer test) to indicate "whether" blood is present. Consequently, DNA profiles extracted from phenolphthalein-positive stains are presumed to be from blood on the evidentiary item and can lead to the identification of "whose" blood is present. Crushed nodules from a variety of legumes yielded phenolphthalein false-positive reactions that were indistinguishable from true bloodstains both in color quality and in developmental time frame. Clothing and other materials stained by nodules also yielded phenolphthalein false-positive reactivity for several years after nodule exposure. Nodules from leguminous plants contain a protein (leghemoglobin) which is structurally and functionally similar to hemoglobin. Testing of purified leghemoglobin confirmed this protein as a source of phenolphthalein reactivity. A scenario is presented showing how the presence of leghemoglobin from nodule staining can mislead investigators. © 2013 American Academy of Forensic Sciences.

  6. Occurrence of polyamines in root nodules of Phaseolus vulgaris in symbiosis with Rhizobium tropici in response to salt stress.

    Science.gov (United States)

    López-Gómez, Miguel; Cobos-Porras, Libertad; Hidalgo-Castellanos, Javier; Lluch, Carmen

    2014-11-01

    Polyamines (PAs) are low molecular weight aliphatic compounds that have been shown to be an important part of plant responses to salt stress. For that reason in this work we have investigated the involvement of PAs in the response to salt stress in root nodules of Phaseolus vulgaris in symbiosis with Rhizobium tropici. The level and variety of PAs was higher in nodules, compared to leaves and roots, and in addition to the common PAs (putrescine, spermidine and spermine) we found homospermidine (Homspd) as the most abundant polyamine in nodules. UPLC-mass spectrometry analysis revealed the presence of 4-aminobutylcadaverine (4-ABcad), only described in nodules of Vigna angularis before. Indeed, the analysis of different nodular fractions revealed higher level of 4-ABcad, as well as Homspd, in bacteroids which indicate the production of these PAs by the bacteria in symbiosis. The genes involved in PAs biosynthesis in nodules displayed an induction under salt stress conditions which was not consistent with the decline of free PAs levels, probably due to the nitrogen limitations provoked by the nitrogenase activity depletion and/or the conversion of free PAs to theirs soluble conjugated forms, that seems to be one of the mechanisms involved in the regulation of PAs levels. On the contrary, cadaverine (Cad) and 4-ABcad concentrations augmented by the salinity, which might be due to their involvement in the response of bacteroids to hyper-osmotic conditions. In conclusion, the results shown in this work suggest the alteration of the bacteroidal metabolism towards the production of uncommon PAs such as 4-ABcad in the response to salt stress in legume root nodules. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Root nodule symbiosis in Lotus japonicus drives the establishment of distinctive rhizosphere, root, and nodule bacterial communities

    Science.gov (United States)

    Zgadzaj, Rafal; Garrido-Oter, Ruben; Jensen, Dorthe Bodker; Koprivova, Anna; Schulze-Lefert, Paul; Radutoiu, Simona

    2016-01-01

    Lotus japonicus has been used for decades as a model legume to study the establishment of binary symbiotic relationships with nitrogen-fixing rhizobia that trigger root nodule organogenesis for bacterial accommodation. Using community profiling of 16S rRNA gene amplicons, we reveal that in Lotus, distinctive nodule- and root-inhabiting communities are established by parallel, rather than consecutive, selection of bacteria from the rhizosphere and root compartments. Comparative analyses of wild-type (WT) and symbiotic mutants in Nod factor receptor5 (nfr5), Nodule inception (nin) and Lotus histidine kinase1 (lhk1) genes identified a previously unsuspected role of the nodulation pathway in the establishment of different bacterial assemblages in the root and rhizosphere. We found that the loss of nitrogen-fixing symbiosis dramatically alters community structure in the latter two compartments, affecting at least 14 bacterial orders. The differential plant growth phenotypes seen between WT and the symbiotic mutants in nonsupplemented soil were retained under nitrogen-supplemented conditions that blocked the formation of functional nodules in WT, whereas the symbiosis-impaired mutants maintain an altered community structure in the nitrogen-supplemented soil. This finding provides strong evidence that the root-associated community shift in the symbiotic mutants is a direct consequence of the disabled symbiosis pathway rather than an indirect effect resulting from abolished symbiotic nitrogen fixation. Our findings imply a role of the legume host in selecting a broad taxonomic range of root-associated bacteria that, in addition to rhizobia, likely contribute to plant growth and ecological performance. PMID:27864511

  8. Towards a better understanding of the role of reactive oxygen species in legume root nodules

    NARCIS (Netherlands)

    Ramos Escribano, J.

    2004-01-01

    Biological N2 fixation is carried out exclusively by prokaryotes, either in the free-living form or in mutualistic symbioses with green algae, legumes and actinorhizal plants. The most agronomica1ly relevant symbiosis is, by fàr, that formed between soil rhizobia and legume roots. In addition, the

  9. The relationship between thiamine and two symbioses: Root nodule symbiosis and arbuscular mycorrhiza.

    Science.gov (United States)

    Nagae, Miwa; Parniske, Martin; Kawaguchi, Masayoshi; Takeda, Naoya

    2016-12-01

    Lotus japonicus THIC is expressed in all organs, and the encoded protein catalyzes thiamine biosynthesis. Loss of function produces chlorosis, a typical thiamine-deficiency phenotype, and mortality. To investigate thiamine's role in symbiosis, we focused on THI1, a thiamine-biosynthesis gene expressed in roots, nodules, and seeds. The thi1 mutant had green leaves, but formed small nodules and immature seeds. These phenotypes were rescued by THI1 complementation and by exogenous thiamine. Thus, THI1 is required for nodule enlargement and seed maturation. On the other hand, colonization by arbuscular mycorrhiza (AM) fungus Rhizophagus irregularis was not affected in the thi1 mutant or by exogenous thiamine. However, spores of R. irregularis stored more thiamine than the source (host plants), despite lacking thiamine biosynthesis genes. Therefore, disturbance of the thiamine supply would affect progeny phenotypes such as spore formation and hyphal growth. Further investigation will be required to elucidate thiamine's effect on AM.

  10. Molecular diversity of legume root-nodule bacteria in Kakadu National Park, Northern Territory, Australia.

    Directory of Open Access Journals (Sweden)

    Bénédicte Lafay

    2007-03-01

    Full Text Available Symbiotic relationships between leguminous plants (family Fabaceae and nodule-forming bacteria in Australia native ecosystems remain poorly characterized despite their importance. Most studies have focused on temperate parts of the country, where the use of molecular approaches have already revealed the presence of Bradyrhizobium, Ensifer (formerly Sinorhizobium, Mesorhizobium and Rhizobium genera of legume root-nodule bacteria. We here provide the first molecular characterization of nodulating bacteria from tropical Australia.45 nodule-forming bacterial strains, isolated from eight native legume hosts at eight locations in Kakadu National Park, Northern Territory, Australia, were examined for their genetic diversity and phylogenetic position. Using SSU rDNA PCR-RFLPs and phylogenetic analyses, our survey identified nine genospecies, two of which, Bradyrhizobium genospp. B and P, had been previously identified in south-eastern Australia and one, Mesorhizobium genospecies AA, in southern France. Three of the five newly characterized Bradyrhizobium genospecies were more closely related to B. japonicum USDA110, whereas the other two belonged to the B. elkanii group. All five were each more closely related to strains sampled in various tropical areas outside Australia than to strains known to occur in Australia. We also characterized an entirely novel nodule-forming lineage, phylogenetically distant from any previously described rhizobial and non-rhizobial legume-nodulating lineage within the Rhizobiales.Overall, the present results support the hypothesis of tropical areas being centres of biodiversity and diversification for legume root-nodule bacteria and confirm the widespread occurrence of Bradyrhizobium genosp. B in continental Australia.

  11. Antioxidant defenses in the peripheral cell layers of legume root nodules.

    Science.gov (United States)

    Dalton, D A; Joyner, S L; Becana, M; Iturbe-Ormaetxe, I; Chatfield, J M

    1998-01-01

    Ascorbate peroxidase (AP) is a key enzyme that scavenges potentially harmful H2O2 and thus prevents oxidative damage in plants, especially in N2-fixing legume root nodules. The present study demonstrates that the nodule endodermis of alfalfa (Medicago sativa) root nodules contains elevated levels of AP protein, as well as the corresponding mRNA transcript and substrate (ascorbate). Enhanced AP protein levels were also found in cells immediately peripheral to the infected region of soybean (Glycine max), pea (Pisum sativum), clover (Trifolium pratense), and common bean (Phaseolus vulgaris) nodules. Regeneration of ascorbate was achieved by (homo)glutathione and associated enzymes of the ascorbate-glutathione pathway, which were present at high levels. The presence of high levels of antioxidants suggests that respiratory consumption of O2 in the endodermis or nodule parenchyma may be an essential component of the O2-diffusion barrier that regulates the entry of O2 into the central region of nodules and ensures optimal functioning of nitrogenase.

  12. Transport and partitioning of CO2 fixed by root nodules of ureide and amide producing legumes

    International Nuclear Information System (INIS)

    Vance, C.P.; Boylan, K.L.M.; Maxwell, C.A.; Heichel, G.H.; Hardman, L.L.

    1985-01-01

    Nodulated and denodulated roots of adzuki bean (Vigna angularis), soybean (Glycine max), and alfalfa (Medicago sativa) were exposed to 14 CO 2 to investigate the contribution of nodule CO 2 fixation to assimilation and transport of fixed nitrogen. The distribution of radioactivity in xylem sap and partitioning of carbon fixed by nodules to the whole plant were measured. Radioactivity in the xylem sap of nodulated soybean and adzuki bean was located primarily (70 to 87%) in the acid fraction while the basic (amino acid) fraction contained 10 to 22%. In contrast radioactivity in the xylem sap of nodulated alfalfa was primarily in amino acids with about 20% in organic acids. Total ureide concentration was 8.1, 4.7, and 0.0 micromoles per milliliter xylem sap for soybean, adzuki bean, and alfalfa, respectively. While the major nitrogen transport products in soybeans and adzuki beans are ureides, this class of metabolites contained less than 20% of the the total radioactivity. When nodules of plants were removed, radioactivity in xylem sap decreased by 90% or more. Pulse-chase experiments indicated that CO 2 fixed by nodules was rapidly transported to shoots and incorporated into acid stable constituents. The data are consistent with a role for nodule CO 2 fixation providing carbon for the assimilation and transport of fixed nitrogen in amide-based legumes. In contrast, CO 2 fixation by nodules of ureide transporting legumes appears to contribute little to assimilation and transport of fixed nitrogen. 19 references, 2 figures, 5 tables

  13. Genetic constraints that determine rhizobium-root nodule formation in Parasponia andersonii

    NARCIS (Netherlands)

    Seifi Kalhor, M.

    2016-01-01

    Bacteria of the genus Rhizobium play a very important role in agriculture by inducing nitrogen-fixing nodules on the roots of legumes. Root nodule symbiosis enables nitrogen‐fixing bacteria (Rhizobium) to convert atmospheric nitrogen into a form that is directly available for plant growth.

  14. Endophytic and epiphytic hydrocarbon-utilizing bacteria associated with root nodules of legumes

    International Nuclear Information System (INIS)

    Dashti, N.; Khanafer, M.; Radwan, S.S.

    2005-01-01

    During their withdrawal from Kuwait in 1991, the Iraqi forces damaged and set fire to approximately 700 oil wells. Oil gushed from the wells for a period of 7 months, resulting in oil lakes which covered about 50 square km of the Kuwaiti desert and posing an environmental problem. Most of the crude oil has been pumped out, leaving the lake bottoms polluted with oil to depths reaching 20 to 25 cm. The oily areas have been mediated through indigenous hydrocarbon-utilizing microorganisms, but recovery is slow. Rhizospheres of crop plants, including legumes, are rich in oil-utilizing bacteria. Cultivation of broad beans in oily desert samples has enhanced oil biodegradation. This paper discussed the evidence that rhizobium strains inside the nodules on roots of broad beans are active in hydrocarbon utilization, and that the nodules are also colonized on their entire surfaces with oil-utilizing bacteria. Nodule-associated hydrocarbon utilizers appear to contribute together with rhizospheric hydrocarbon utilizers to the phytoremediation of oily soil. Broad beans were removed from soil and their root surfaces were sterilized to eliminate rhizospheric microorganisms. Plants with intact nodules were tested for their potential of attenuating to crude oil in water. Plants were divided into 2 groups: control plants in which all nodules were removed; and experimental plants which were used directly without further treatment. To isolate rhizobium from inside the nodules, fresh nodules were washed, sterilized and homogenized in sterile water. Bacterial strains were tested for their hydrocarbon utilization potential by streaking cell suspensions on the surface of sterile inorganic mediums containing 1 per cent of crude oil or of individual pure aliphatic and aromatic test hydrocarbons. All bacterial isolates were tested for growth on a solid Ashbery's nitrogen free medium. Results indicated that hydrocarbons were more efficiently eliminated from water supporting disinfected

  15. Rhizobium cauense sp. nov., isolated from root nodules of the herbaceous legume Kummerowia stipulacea grown in campus lawn soil.

    Science.gov (United States)

    Liu, Tian Yan; Li, Ying; Liu, Xiao Xiao; Sui, Xin Hua; Zhang, Xiao Xia; Wang, En Tao; Chen, Wen Xin; Chen, Wen Feng; Puławska, Joanna

    2012-10-01

    Three bacterial isolates (CCBAU 101002(T), CCBAU 101000 and CCBAU 101001) originating from root nodules of the herbaceous legume Kummerowia stipulacea grown in the campus lawn of China Agricultural University were characterized with a polyphasic taxonomic approach. Comparative 16S rRNA gene sequence analysis showed that the isolates shared 99.85-99.92% sequence similarities and had the highest similarities to the type strains of Rhizobium mesoamericanum (99.31%), R. endophyticum (98.54%), R. tibeticum (98.38%) and R. grahamii (98.23%). Sequence similarity of four concatenated housekeeping genes (atpD, glnII, recA and rpoB) between CCBAU 101002(T) and its closest neighbor (R. grahamii) was 92.05%. DNA-DNA hybridization values between strain CCBAU 101002(T) and the four type strains of the most closely related Rhizobium species were less than 28.4±0.8%. The G+C mol% of the genomic DNA for strain CCBAU 101002(T) was 58.5% (Tm). The major respiratory quinone was ubiquinone (Q-10). Summed feature 8 (18:1ω7cis/18:1ω6cis) and 16:0 were the predominant fatty acids. Strain CCBAU 101002(T) contained phosphatidylcholine and phosphatidylethanolamine as major polar lipids, and phosphatidylglycerol and cardiolipin as minor ones. No glycolipid was detected. Unlike other strains, this novel species could utilize dulcite or sodium pyruvate as sole carbon sources and it was resistant to 2% (w/v) NaCl. On the basis of the polyphasic study, a new species Rhizobium cauense sp. nov. is proposed, with CCBAU 101002(T) (=LMG 26832(T)=HAMBI 3288(T)) as the type strain. Copyright © 2012 Elsevier GmbH. All rights reserved.

  16. Preparation of Artificial Blood from the Extract of Legume Root Nodules, and the Creation of Artificial Latent Fingermarks in Blood Using Artificial Blood.

    Science.gov (United States)

    Hong, Sungwook; Kim, Chaewon; Jeon, Soyoung; Lee, Eunhye

    2018-01-01

    Distribution of homogeneous fingermarks in blood is essential for conducting proficiency tests in forensic science. Hence, the artificial blood was prepared using the root nodule extract of Glycine max plants. The reactivity of the artificial blood with widely used human blood detection reagents was tested. Artificial latent fingermarks in blood were printed using an inkjet cartridge case filled with artificial blood solution. The artificial latent fingermarks in blood were developed with amino acid-sensitive reagents and could obtain development as prominent as the image of the master fingermark saved on the computer. Therefore, it has been confirmed that the extract of legume root nodules can be used as artificial blood, and the artificial blood can be used for the preparation of artificial latent fingermarks or footmarks in blood. © 2017 American Academy of Forensic Sciences.

  17. The symbiosis between Rhizobium leguminosarum and Pisum sativum : regulation of the nitrogenase activity

    OpenAIRE

    Appels, M.A.

    1989-01-01

    Bacteria of the genus Rhizobium can form a symbiosis with plants of the family Leguminosae. Both bacteria and plant show considerable biochemical and morphological changes in order to develop and carry out the symbiosis. The Rhizobia induce special structures on the legumes, which are called root nodules. In these root nodules, the differentiated bacteria - so-called bacteroids - are localized. Within the root nodule the bacteroid...

  18. Expression of nodule-specific genes in alfalfa root nodules blocked at an early stage of development.

    NARCIS (Netherlands)

    Dickstein, R.; Bisseling, T.; Reinhold, V.N.; Ausubel, F.M.

    1988-01-01

    To help dissect the molecular basis of the Rhizobium-legume symbiosis, we used in vitro translation and Northern blot analysis of nodule RNA to examine alfalfa-specific genes (nodulins) expressed in two types of developmentally defective root nodules elicited by Rhizobium meliloti. Fix- nodules were

  19. Compatibility between Legumes and Rhizobia for the Establishment of a Successful Nitrogen-Fixing Symbiosis.

    Science.gov (United States)

    Clúa, Joaquín; Roda, Carla; Zanetti, María Eugenia; Blanco, Flavio A

    2018-02-27

    The root nodule symbiosis established between legumes and rhizobia is an exquisite biological interaction responsible for fixing a significant amount of nitrogen in terrestrial ecosystems. The success of this interaction depends on the recognition of the right partner by the plant within the richest microbial ecosystems on Earth, the soil. Recent metagenomic studies of the soil biome have revealed its complexity, which includes microorganisms that affect plant fitness and growth in a beneficial, harmful, or neutral manner. In this complex scenario, understanding the molecular mechanisms by which legumes recognize and discriminate rhizobia from pathogens, but also between distinct rhizobia species and strains that differ in their symbiotic performance, is a considerable challenge. In this work, we will review how plants are able to recognize and select symbiotic partners from a vast diversity of surrounding bacteria. We will also analyze recent advances that contribute to understand changes in plant gene expression associated with the outcome of the symbiotic interaction. These aspects of nitrogen-fixing symbiosis should contribute to translate the knowledge generated in basic laboratory research into biotechnological advances to improve the efficiency of the nitrogen-fixing symbiosis in agronomic systems.

  20. Microvirga ossetica sp. nov., a species of rhizobia isolated from root nodules of the legume species Vicia alpestris Steven.

    Science.gov (United States)

    Safronova, Vera I; Kuznetsova, Irina G; Sazanova, Anna L; Belimov, Andrey A; Andronov, Evgeny E; Chirak, Elizaveta R; Osledkin, Yuri S; Onishchuk, Olga P; Kurchak, Oksana N; Shaposhnikov, Alexander I; Willems, Anne; Tikhonovich, Igor A

    2017-01-01

    Gram-stain-negative strains V5/3MT, V5/5K, V5/5M and V5/13 were isolated from root nodules of Vicia alpestris plants growing in the North Ossetia region (Caucasus). Sequencing of the partial 16S rRNA gene (rrs) and four housekeeping genes (dnaK, gyrB, recA and rpoB) showed that the isolates from V. alpestris were most closely related to the species Microvirga zambiensis (order Rhizobiales, family Methylobacteriaceae) which was described for the single isolate from root nodule of Listia angolensis growing in Zambia. Sequence similarities between the Microvirga-related isolates and M. zambiensis WSM3693T ranged from 98.5 to 98.7 % for rrs and from 79.7 to 95.8 % for housekeeping genes. Cellular fatty acids of the isolates V5/3MT, V5/5K, V5/5M and V5/13 included important amounts of C18 : 1ω7c (54.0-67.2 %), C16 : 0 (6.0-7.8 %), C19 : 0 cyclo ω8c (3.1-10.2 %), summed feature 2 (comprising one or more of iso-C16 : 1 I, C14 : 0 3-OH and unknown ECL 10.938, 5.8-22.5 %) and summed feature 3 (comprising C16 : 1ω7c and/or iso-C15 : 02-OH, 2.9-4.0 %). DNA-DNA hybridization between the isolate V5/3MT and M. zambiensis WSM3693T revealed DNA-DNA relatedness of 35.3 %. Analysis of morphological and physiological features of the novel isolates demonstrated their unique phenotypic profile in comparison with reference strains from closely related species of the genus Microvirga. On the basis of genotypic and phenotypic analysis, a novel species named Microvirga ossetica sp. nov. is proposed. The type strain is V5/3MT (=LMG 29787T=RCAM 02728T). Three additional strains of the species are V5/5K, V5/5M and V5/13.

  1. Root nodule symbiosis in Lotus japonicus drives the establishment of distinctive rhizosphere, root, and nodule bacterial communities

    OpenAIRE

    Zgadzaj, Rafal; Garrido-Oter, Ruben; Jensen, Dorthe Bodker; Koprivova, Anna; Schulze-Lefert, Paul; Radutoiu, Simona

    2016-01-01

    Legumes are known as pioneer plants colonizing marginal soils, and as enhancers of the nutritional status in cultivated soils. This beneficial activity has been explained by their capacity to engage in symbiotic relationship with nitrogen-fixing rhizobia. We performed a community profiling analysis of Lotus japonicus wild type and mutants to investigate the role of the nodulation pathway on the structure of the root-associated bacterial microbiota. We found that several bacterial orders were ...

  2. LysM-Type Mycorrhizal Receptor Recruited for Rhizobium Symbiosis in Nonlegume Parasponia

    NARCIS (Netherlands)

    Camp, Op den R.H.M.; Streng, A.J.; Mita, De S.; Cao, Q.; Polone, E.; Liu, W.; Ammiraju, J.S.S.; Kudrna, D.; Wing, R.; Untergasser, A.; Bisseling, T.; Geurts, R.

    2011-01-01

    Rhizobium root nodule symbiosis is generally considered to be unique for legumes. However, there is one exception and that is Parasponia. In this nonlegume, the rhizobial nodule symbiosis evolved independently and is, like in legumes, induced by rhizobium Nod factors. We used Parasponia to identify

  3. Formation of organelle-like N2-fixing symbiosomes in legume root nodules is controlled by DMI2

    NARCIS (Netherlands)

    Limpens, E.H.M.; Mirabella, R.; Fedorova, E.; Franken, C.; Franssen, H.; Bisseling, T.; Geurts, R.

    2005-01-01

    In most legume nodules, the N2-fixing rhizobia are present as organelle-like structures inside their host cells. These structures, named symbiosomes, contain one or a few rhizobia surrounded by a plant membrane. Symbiosome formation requires the release of bacteria from cell-wall-bound infection

  4. Immunosuppression during Rhizobium-legume symbiosis.

    Science.gov (United States)

    Luo, Li; Lu, Dawei

    2014-01-01

    Rhizobium infects host legumes to elicit new plant organs, nodules where dinitrogen is fixed as ammonia that can be directly utilized by plants. The nodulation factor (NF) produced by Rhizobium is one of the determinant signals for rhizobial infection and nodule development. Recently, it was found to suppress the innate immunity on host and nonhost plants as well as its analogs, chitins. Therefore, NF can be recognized as a microbe/pathogen-associated molecular pattern (M/PAMP) like chitin to induce the M/PAMP triggered susceptibility (M/PTS) of host plants to rhizobia. Whether the NF signaling pathway is directly associated with the innate immunity is not clear till now. In fact, other MAMPs such as lipopolysaccharide (LPS), exopolysaccharide (EPS) and cyclic-β-glucan, together with type III secretion system (T3SS) effectors are also required for rhizobial infection or survival in leguminous nodule cells. Interestingly, most of them play similarly negative roles in the innate immunity of host plants, though their signaling is not completely elucidated. Taken together, we believe that the local immunosuppression on host plants induced by Rhizobium is essential for the establishment of their symbiosis.

  5. Does plant immunity have a central role in the legume rhizobium symbiosis?

    Directory of Open Access Journals (Sweden)

    Katalin eToth

    2015-06-01

    Full Text Available Plants are exposed to many different microbes in their habitat. These microbes may be benign or pathogenic, but in some cases they are beneficial. The rhizosphere provides an especially rich palette for colonization by beneficial (associative and symbiotic microorganisms, which raises the question as to how roots can distinguish such ‘friends’ from possible ‘foes’ (i.e., pathogens. Plants possess an innate immunity system that can recognize pathogens, through an arsenal of protein receptors. These receptors include receptor-like kinases (RLK and receptor-like proteins (RLP located at the plasma membrane, as well as intracellular receptors (so called NBS-LRR proteins or R proteins that recognize molecules released by microbes into the plant cell. The key rhizobial, symbiotic signaling molecule (called Nod factor is perceived by the host legume plant using LysM-domain containing RLKs. Perception of the symbiotic Nod factor triggers signaling cascades leading to bacterial infection and accommodation of the symbiont in a newly formed root organ, the nodule, resulting in a nitrogen-fixing root nodule symbiosis (RNS. The net result of this symbiosis is the intracellular colonization of the plant with thousands of bacteria; a process that seems to occur in spite of the immune ability of plants to prevent pathogen infection. In this review, we discuss the potential of the invading rhizobial symbiont to actively avoid this innate immunity response, as well as specific examples of where the plant immune response may modulate rhizobial infection and host range.

  6. Root nodule organogenesis : molecular characterization of the zonation central tissue

    NARCIS (Netherlands)

    Yang, W.C.

    1994-01-01

    Legume plants form root nodules by interacting with the soil bacterium, Rhizobium. In these nodules bacteria are able to convert atmospheric nitrogen into ammonia which is used by the host plants as nitrogen source. Therefore symbiotic nitrogen fixation in root nodules

  7. A histochemical study of root nodule development

    NARCIS (Netherlands)

    Wiel, van de C.

    1991-01-01

    In cooperation with soil bacteria of the genera Rhizobium , Bradyrhizobium or Azorhizobium , many members of the legume family are able to form specialized organs on their roots, called root nodules. The bacteria, wrapped up

  8. [LEGUME-RHIZOBIUM SYMBIOSIS PROTEOMICS: ACHIEVEMENTS AND PERSPECTIVES].

    Science.gov (United States)

    Kondratiuk, Iu Iu; Mamenko, P M; Kots, S Ya

    2015-01-01

    The present review contains results of proteomic researches of legume-rhizobium symbiosis. The technical difficulties associated with the methods of obtaining protein extracts from symbiotic structures and ways of overcoming them were discussed. The changes of protein synthesis under formation and functioning of symbiotic structures were shown. Special attention has been given to the importance of proteomic studies of plant-microbe structures in the formation of adaptation strategies under adverse environmental conditions. The technical and conceptual perspectives of legume-rhizobium symbiosis proteomics were shown.

  9. R gene-controlled host specificity in the legume-rhizobia symbiosis

    Science.gov (United States)

    Leguminous plants can enter into root nodule symbioses with nitrogen-fixing soil bacteria known as rhizobia. An intriguing but still poorly understood property of the symbiosis is its host specificity, which is controlled at multiple levels involving both rhizobial and host genes. Here we report the...

  10. Probing nod factor perception in legumes by fluorescence microspectroscopy

    NARCIS (Netherlands)

    Goedhart, J.

    2001-01-01

    Plants of the family of legumes are capable of forming a symbiosis with Rhizobium bacteria. These Gram-negative bacteria invade the root system of a host legume and fix nitrogen in a specialized organ, the so-called root nodule. In exchange for sugars, the bacteria convert atmospheric

  11. Does plant immunity play a critical role during initiation of the legume-rhizobium symbiosis?

    Science.gov (United States)

    Tóth, Katalin; Stacey, Gary

    2015-01-01

    Plants are exposed to many different microbes in their habitats. These microbes may be benign or pathogenic, but in some cases they are beneficial for the host. The rhizosphere provides an especially rich palette for colonization by beneficial (associative and symbiotic) microorganisms, which raises the question as to how roots can distinguish such 'friends' from possible 'foes' (i.e., pathogens). Plants possess an innate immune system that can recognize pathogens, through an arsenal of protein receptors, including receptor-like kinases (RLKs) and receptor-like proteins (RLPs) located at the plasma membrane. In addition, the plant host has intracellular receptors (so called NBS-LRR proteins or R proteins) that directly or indirectly recognize molecules released by microbes into the plant cell. A successful cooperation between legume plants and rhizobia leads to beneficial symbiotic interaction. The key rhizobial, symbiotic signaling molecules [lipo-chitooligosaccharide Nod factors (NF)] are perceived by the host legume plant using lysin motif-domain containing RLKs. Perception of the symbiotic NFs trigger signaling cascades leading to bacterial infection and accommodation of the symbiont in a newly formed root organ, the nodule, resulting in a nitrogen-fixing root nodule symbiosis. The net result of this symbiosis is the intracellular colonization of the plant with thousands of bacteria; a process that seems to occur in spite of the immune ability of plants to prevent pathogen infection. In this review, we discuss the potential of the invading rhizobial symbiont to actively avoid this innate immune response, as well as specific examples of where the plant immune response may modulate rhizobial infection and host range.

  12. A Genomic Encyclopedia of the Root Nodule Bacteria: assessing genetic diversity through a systematic biogeographic survey.

    Science.gov (United States)

    Reeve, Wayne; Ardley, Julie; Tian, Rui; Eshragi, Leila; Yoon, Je Won; Ngamwisetkun, Pinyaruk; Seshadri, Rekha; Ivanova, Natalia N; Kyrpides, Nikos C

    2015-01-01

    Root nodule bacteria are free-living soil bacteria, belonging to diverse genera within the Alphaproteobacteria and Betaproteobacteria, that have the capacity to form nitrogen-fixing symbioses with legumes. The symbiosis is specific and is governed by signaling molecules produced from both host and bacteria. Sequencing of several model RNB genomes has provided valuable insights into the genetic basis of symbiosis. However, the small number of sequenced RNB genomes available does not currently reflect the phylogenetic diversity of RNB, or the variety of mechanisms that lead to symbiosis in different legume hosts. This prevents a broad understanding of symbiotic interactions and the factors that govern the biogeography of host-microbe symbioses. Here, we outline a proposal to expand the number of sequenced RNB strains, which aims to capture this phylogenetic and biogeographic diversity. Through the Vavilov centers of diversity (Proposal ID: 231) and GEBA-RNB (Proposal ID: 882) projects we will sequence 107 RNB strains, isolated from diverse legume hosts in various geographic locations around the world. The nominated strains belong to nine of the 16 currently validly described RNB genera. They include 13 type strains, as well as elite inoculant strains of high commercial importance. These projects will strongly support systematic sequence-based studies of RNB and contribute to our understanding of the effects of biogeography on the evolution of different species of RNB, as well as the mechanisms that determine the specificity and effectiveness of nodulation and symbiotic nitrogen fixation by RNB with diverse legume hosts.

  13. Nodulation and Rhizobium Population in Root Nodules of Selected ...

    African Journals Online (AJOL)

    Nodulation and rhizobium population in root nodules of 5- year old Leucaena leucocephala; Gliricidia sepium and Acacia mangium were assessed. Nodules of these tree legumes were quantified in terms of their numbers, lateral and vertical distribution while the rhizobium population in cultured nodules was counted as ...

  14. Widespread fitness alignment in the legume-rhizobium symbiosis.

    Science.gov (United States)

    Friesen, Maren L

    2012-06-01

    Although 'cheaters' potentially destabilize the legume-rhizobium mutualism, we lack a comprehensive review of host-symbiont fitness correlations. Studies measuring rhizobium relative or absolute fitness and host benefit are surveyed. Mutant studies are tallied for evidence of pleiotropy; studies of natural strains are analyzed with meta-analysis. Of 80 rhizobium mutations, 19 decrease both partners' fitness, four increase both, two increase host fitness but decrease symbiont fitness and none increase symbiont fitness at the host's expense. The pooled correlation between rhizobium nodulation competitiveness and plant aboveground biomass is 0.65 across five experiments that compete natural strains against a reference, whereas, across 14 experiments that compete rhizobia against soil populations or each other, the pooled correlation is 0.24. Pooled correlations between aboveground biomass and nodule number and nodule biomass are 0.76 and 0.83. Positive correlations between legume and rhizobium fitness imply that most ineffective rhizobia are 'defective' rather than 'defectors'; this extends to natural variants, with only one significant fitness conflict. Most studies involve non-coevolved associations, indicating that fitness alignment is the default state. Rhizobium mutations that increase both host and symbiont fitness suggest that some plants maladaptively restrict symbiosis with novel strains. © 2012 The Author. New Phytologist © 2012 New Phytologist Trust.

  15. The Ribosomal RNA is a Useful Marker to Visualize Rhizobia Interacting with Legume Plants

    Science.gov (United States)

    Rinaudi, Luciana; Isola, Maria C.; Giordano, Walter

    2004-01-01

    Symbiosis between rhizobia and leguminous plants leads to the formation of nitrogen-fixing root nodules. In the present article, we recommend the use of the ribosomal RNA (rRNA) isolated from legume nodules in an experimental class with the purpose of introducing students to the structure of eukaryotic and prokaryotic ribosomes and of…

  16. W342F Mutation in CCaMK Enhances Its Affinity to Calmodulin But Compromises Its Role in Supporting Root Nodule Symbiosis in Medicago truncatula

    Directory of Open Access Journals (Sweden)

    Edgard Jauregui

    2017-11-01

    Full Text Available The calcium/calmodulin-dependent protein kinase (CCaMK is regulated by free Ca2+ and Ca2+-loaded calmodulin. This dual binding is believed to be involved in its regulation and associated physiological functions, although direct experimental evidence for this is lacking. Here we document that site-directed mutations in the calmodulin-binding domain of CCaMK alters its binding capacity to calmodulin, providing an effective approach to study how calmodulin regulates CCaMK in terms of kinase activity and regulation of rhizobial symbiosis in Medicago truncatula. We observed that mutating the tryptophan at position 342 to phenylalanine (W342F markedly increased the calmodulin-binding capability of the mutant. The mutant CCaMK underwent autophosphorylation and catalyzed substrate phosphorylation in the absence of calcium and calmodulin. When the mutant W342F was expressed in ccamk-1 roots, the transgenic roots exhibited an altered nodulation phenotype. These results indicate that altering the calmodulin-binding domain of CCaMK could generate a constitutively activated kinase with a negative role in the physiological function of CCaMK.

  17. Phytoremediation of heavy and transition metals aided by legume-rhizobia symbiosis

    DEFF Research Database (Denmark)

    Hao, X.; Taghavi, S.; Xie, P.

    2014-01-01

    Legumes are important for nitrogen cycling in the environment and agriculture due to the ability of nitrogen fixation by rhizobia. In this review, we introduce an important and potential role of legume-rhizobia symbiosis in aiding phytoremediation of some metal contaminated soils as various legumes...... nitrogen fixation, phosphorus solubilization, phytohormone synthesis, siderophore release, and production of ACC deaminase and the volatile compounds of acetoin and 2, 3-butanediol may facilitate legume growth while lessening metal toxicity. The benefits of using legumes inoculated with naturally resistant...

  18. Possible role of glutamine synthetase in the NO signaling response in root nodules by contributing to the antioxidant defenses

    Directory of Open Access Journals (Sweden)

    Liliana Santos Silva

    2013-09-01

    Full Text Available Nitric oxide (NO is emerging as an important regulatory player in the Rhizobium-legume symbiosis. The occurrence of NO during several steps of the symbiotic interaction suggests an important, but yet unknown, signaling role of this molecule for root nodule formation and functioning. The identification of the molecular targets of NO is key for the assembly of the signal transduction cascade that will ultimately help to unravel NO function. We have recently shown that the key nitrogen assimilatory enzyme Glutamine Synthetase (GS is a molecular target of NO in root nodules of Medicago truncatula, being post-translationally regulated by tyrosine nitration in relation to nitrogen fixation. In functional nodules of M. truncatula NO formation has been located in the bacteroid containing cells of the fixation zone, where the ammonium generated by bacterial nitrogenase is released to the plant cytosol and assimilated into the organic pools by plant GS. We propose that the NO-mediated GS post-translational inactivation is connected to nitrogenase inhibition induced by NO and is related to metabolite channeling to boost the nodule antioxidant defenses. Glutamate, a substrate for GS activity is also the precursor for the synthesis of glutathione (GSH, which is highly abundant in root nodules of several plant species and known to play a major role in the antioxidant defense participating in the ascorbate/GSH cycle. Existing evidence suggests that upon NO-mediated GS inhibition, glutamate could be channeled for the synthesis of GSH. According to this hypothesis, GS would be involved in the NO-signaling responses in root nodules and the NO-signaling events would meet the nodule metabolic pathways to provide an adaptive response to the inhibition of symbiotic nitrogen fixation by reactive nitrogen species (RNS.

  19. Infection and Invasion of Roots by Symbiotic, Nitrogen-Fixing Rhizobia during Nodulation of Temperate Legumes

    OpenAIRE

    Gage, Daniel J.

    2004-01-01

    Bacteria belonging to the genera Rhizobium, Mesorhizobium, Sinorhizobium, Bradyrhizobium, and Azorhizobium (collectively referred to as rhizobia) grow in the soil as free-living organisms but can also live as nitrogen-fixing symbionts inside root nodule cells of legume plants. The interactions between several rhizobial species and their host plants have become models for this type of nitrogen-fixing symbiosis. Temperate legumes such as alfalfa, pea, and vetch form indeterminate nodules that a...

  20. [Possible involvement of hydrogen peroxide and salicylic acid in the legume-rhizobium symbiosis].

    Science.gov (United States)

    Glian'ko, A K; Makarova, L E; Vasil'eva, G G; Mironova, N V

    2005-01-01

    H2O2 content was studied in the roots and epicotyls of pea (Pisum sativum L.) with normal (cultivar Marat) and disturbed (non-nodulating mutant K14 and hypernodulating mutant Nod3) regulation of root nodulation after inoculation with active industrial strain of Rhizobium leguminosarum by. viceae 250a/CIAM 1026. Pea biotypes differed by H2O2 content in the roots and epicotyls. Exogenous salicylic acid (SA) (0.2 mM) affected H2O2 and SA contents in the roots in an inoculation-dependent manner. The involvement of hydrogen peroxide and SA as signaling molecules as well as of antibacterial agents in the pea-rhizobium interaction at the initial stages of symbiosis is proposed.

  1. Reactive oxygen and nitrogen species and glutathione: key players in the legume-Rhizobium symbiosis.

    Science.gov (United States)

    Pauly, Nicolas; Pucciariello, Chiara; Mandon, Karine; Innocenti, Gilles; Jamet, Alexandre; Baudouin, Emmanuel; Hérouart, Didier; Frendo, Pierre; Puppo, Alain

    2006-01-01

    Several reactive oxygen and nitrogen species (ROS/RNS) are continuously produced in plants as by-products of aerobic metabolism or in response to stresses. Depending on the nature of the ROS and RNS, some of them are highly toxic and rapidly detoxified by various cellular enzymatic and non-enzymatic mechanisms. Whereas plants have many mechanisms with which to combat increased ROS/RNS levels produced during stress conditions, under other circumstances plants appear to generate ROS/RNS as signalling molecules to control various processes encompassing the whole lifespan of the plant such as normal growth and development stages. This review aims to summarize recent studies highlighting the involvement of ROS/RNS, as well as the low molecular weight thiols, glutathione and homoglutathione, during the symbiosis between rhizobia and leguminous plants. This compatible interaction initiated by a molecular dialogue between the plant and bacterial partners, leads to the formation of a novel root organ capable of fixing atmospheric nitrogen under nitrogen-limiting conditions. On the one hand, ROS/RNS detection during the symbiotic process highlights the similarity of the early response to infection by pathogenic and symbiotic bacteria, addressing the question as to which mechanism rhizobia use to counteract the plant defence response. Moreover, there is increasing evidence that ROS are needed to establish the symbiosis fully. On the other hand, GSH synthesis appears to be essential for proper development of the root nodules during the symbiotic interaction. Elucidating the mechanisms that control ROS/RNS signalling during symbiosis could therefore contribute in defining a powerful strategy to enhance the efficiency of the symbiotic interaction.

  2. Study of phenanthrene utilizing bacterial consortia associated with cowpea (Vigna unguiculata) root nodules.

    Science.gov (United States)

    Sun, Ran; Crowley, David E; Wei, Gehong

    2015-02-01

    Many legumes have been selected as model plants to degrade organic contaminants with their special associated rhizosphere microbes in soil. However, the function of root nodules during microbe-assisted phytoremediation is not clear. A pot study was conducted to examine phenanthrene (PHE) utilizing bacteria associated with root nodules and the effects of cowpea root nodules on phytoremediation in two different types of soils (freshly contaminated soil and aged contaminated soil). Cowpea nodules in freshly-contaminated soil showed less damage in comparison to the aged-contaminated soil, both morphologically and ultra-structurally by scanning electron microscopy. The study of polycyclic aromatic hydrocarbon (PAH) attenuation conducted by high performance liquid chromatography revealed that more PAH was eliminated from liquid culture around nodulated roots than nodule-free roots. PAH sublimation and denaturation gradient gel electrophoresis were applied to analyze the capability and diversity of PAH degrading bacteria from the following four parts of rhizo-microzone: bulk soil, root surface, nodule surface and nodule inside. The results indicated that the surface and inside of cowpea root nodules were colonized with bacterial consortia that utilized PHE. Our results demonstrated that root nodules not only fixed nitrogen, but also enriched PAH-utilizing microorganisms both inside and outside of the nodules. Legume nodules may have biotechnological values for PAH degradation.

  3. Expression of a complete soybean leghemoglobin gene in root nodules of transgenic Lotus corniculatus

    DEFF Research Database (Denmark)

    Stougaard, J; Petersen, T E; Marcker, K A

    1987-01-01

    The complete soybean leghemoglobin lbc(3) gene was transferred into the legume Lotus corniculatus using an Agrobacterium rhizogenes vector system. Organ-specific expression of the soybean gene was observed in root nodules formed on regenerated transgenic plants after infection with Rhizobium loti...

  4. Microgravity effects on the legume/Rhizobium symbiosis

    Science.gov (United States)

    Urban, James E.

    1997-01-01

    Symbiotic nitrogen fixation is of critical importance to world agriculture and likely will be a critical part of life support systems developed for prolonged missions in space. Bacteroid formation, an essential step in an effective Dutch White Clover/Rhizobium leguminosarum bv trifolii symbiosis, is induced by succinic acid which is produced by the plant and which is bound and incorporated by the bacterium. Aspirin mimics succinate in its role as a bacteroid inducer and measures of aspirin binding mimiced measurements of succinate binding. In normal gravity (1×g), rhizobium bacteria immediately bound relatively high levels of aspirin (or succinate) in a readily reversible manner. Within a few seconds a portion of this initially bound aspirin became irreversibly bound. In the microgravity environment aboard the NASA 930 aircraft, rhizobia did not display the initial reversible binding of succinate, but did display a similar kinetic pattern of irreversible binding, and ultimately bound 32% more succinate (Acta Astronautica 36:129-133, 1995.) In normal gravity succinate treated cells stop dividing and swell to their maximum size (twice the normal cell volume) within a time equivalent to the time required for two normal cell doublings. Swelling in microgravity was tested in FPA and BPM sample holders aboard the space shuttle (USML-1, and STS-54, 57, and 60.) The behavior of cells in the two sample holders was similar, and swelling behavior of cells in microgravity was identical to behavior in normal gravity.

  5. Mutualism and Adaptive Divergence: Co-Invasion of a Heterogeneous Grassland by an Exotic Legume-Rhizobium Symbiosis

    Science.gov (United States)

    Porter, Stephanie S.; Stanton, Maureen L.; Rice, Kevin J.

    2011-01-01

    Species interactions play a critical role in biological invasions. For example, exotic plant and microbe mutualists can facilitate each other's spread as they co-invade novel ranges. Environmental context may influence the effect of mutualisms on invasions in heterogeneous environments, however these effects are poorly understood. We examined the mutualism between the legume, Medicago polymorpha, and the rhizobium, Ensifer medicae, which have both invaded California grasslands. Many of these invaded grasslands are composed of a patchwork of harsh serpentine and relatively benign non-serpentine soils. We grew legume genotypes collected from serpentine or non-serpentine soil in both types of soil in combination with rhizobium genotypes from serpentine or non-serpentine soils and in the absence of rhizobia. Legumes invested more strongly in the mutualism in the home soil type and trends in fitness suggested that this ecotypic divergence was adaptive. Serpentine legumes had greater allocation to symbiotic root nodules in serpentine soil than did non-serpentine legumes and non-serpentine legumes had greater allocation to nodules in non-serpentine soil than did serpentine legumes. Therefore, this invasive legume has undergone the rapid evolution of divergence for soil-specific investment in the mutualism. Contrary to theoretical expectations, the mutualism was less beneficial for legumes grown on the stressful serpentine soil than on the non-serpentine soil, possibly due to the inhibitory effects of serpentine on the benefits derived from the interaction. The soil-specific ability to allocate to a robust microbial mutualism may be a critical, and previously overlooked, adaptation for plants adapting to heterogeneous environments during invasion. PMID:22174755

  6. Metabolomic profiling reveals suppression of oxylipin biosynthesis during the early stages of legume-rhizobia symbiosis.

    Science.gov (United States)

    Zhang, Na; Venkateshwaran, Muthusubramanian; Boersma, Melissa; Harms, Amy; Howes-Podoll, Maegen; den Os, Désirée; Ané, Jean-Michel; Sussman, Michael R

    2012-09-21

    The establishment of symbiosis between leguminous plants and rhizobial bacteria requires rapid metabolic changes in both partners. We utilized untargeted quantitative mass spectrometry to perform metabolomic profiling of small molecules in extracts of the model legume Medicago truncatula treated with rhizobial Nod factors. One metabolite closely resembling the 9(R)-HODE class of oxylipins reproducibly showed a decrease in concentration within the first hour of in planta nod factor treatment. Oxylipins are precursors of the jasmonic acid biosynthetic pathway and we showed that both this metabolite and jasmonic acid inhibit Nod factor signaling. Since, oxylipins have been implicated as antimicrobial compounds produced by plants, these observations suggest that the oxylipin pathway may play multiple roles in facilitating Nod factor signaling during the early stages of symbiosis. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  7. CARBON CYCLES, NITROGEN FIXATION AND THE LEGUME-RHIZOBIA SYMBIOSIS AS SOIL CONTAMINANT BIOTEST SYSTEM

    Directory of Open Access Journals (Sweden)

    Dietrich Werner

    2008-06-01

    Full Text Available The major pools and turnover  rates of the global carbon (C cycles are presented and compared to the human production of CO2  from the burning of fossil fuels (e.g. coal and oil and geothermal  fuels (natural  gases, both categorized as non-renewable energy resources which  in amount  reaches around  6.5 Gigatons C per year. These pools that serve as C-holding stallions  are in the atmosphere,  the land plant biomass, the organic soils carbon, the ocean carbon and the lithosphere. In another related case, the present focus in the area of nitrogen  fixation  is discussed with  data on world  production of grain  legumes  compared  to cereals production and nitrogen  fertilizer use. The focus to understand  the molecular  biology of the legume-rhizobia symbiosis as a major contributor to nitrogen  fixation  is in the areas of signal exchange between  host plants and rhizobia  in the rhizophere including  the nod factor signalling, the infection  and nodule compartmentation and the soils stress factors affecting the symbiosis. The use of the Legume-Rhizobia symbiosis as a biotest system for soil contaminants includes data for cadmium,  arsenate, atrazine,  lindane,  fluoranthene, phenantrene and acenaphthene and also results  on the mechanism,  why the symbiotic system is more sensitive  than test systems with plant growth  parameters.

  8. A Legume TOR Protein Kinase Regulates Rhizobium Symbiosis and Is Essential for Infection and Nodule Development.

    Science.gov (United States)

    Nanjareddy, Kalpana; Blanco, Lourdes; Arthikala, Manoj-Kumar; Alvarado-Affantranger, Xóchitl; Quinto, Carmen; Sánchez, Federico; Lara, Miguel

    2016-11-01

    The target of rapamycin (TOR) protein kinase regulates metabolism, growth, and life span in yeast, animals, and plants in coordination with nutrient status and environmental conditions. The nutrient-dependent nature of TOR functionality makes this kinase a putative regulator of symbiotic associations involving nutrient acquisition. However, TOR's role in these processes remains to be understood. Here, we uncovered the role of TOR during the bean (Phaseolus vulgaris)-Rhizobium tropici (Rhizobium) symbiotic interaction. TOR was expressed in all tested bean tissues, with higher transcript levels in the root meristems and senesced nodules. We showed TOR promoter expression along the progressing infection thread and in the infected cells of mature nodules. Posttranscriptional gene silencing of TOR using RNA interference (RNAi) showed that this gene is involved in lateral root elongation and root cell organization and also alters the density, size, and number of root hairs. The suppression of TOR transcripts also affected infection thread progression and associated cortical cell divisions, resulting in a drastic reduction of nodule numbers. TOR-RNAi resulted in reduced reactive oxygen species accumulation and altered CyclinD1 and CyclinD3 expression, which are crucial factors for infection thread progression and nodule organogenesis. Enhanced expression of TOR-regulated ATG genes in TOR-RNAi roots suggested that TOR plays a role in the recognition of Rhizobium as a symbiont. Together, these data suggest that TOR plays a vital role in the establishment of root nodule symbiosis in the common bean. © 2016 American Society of Plant Biologists. All Rights Reserved.

  9. [The Effect of Cadmium on the Efficiency of Development of Legume-Rhizobium Symbiosis].

    Science.gov (United States)

    Chuhukova, O V; Postrigan, B N; Baimiev, A Kh; Chemeris, A V

    2015-01-01

    Screening of nodule bacteria (rhizobia) forming symbiotic relationships with legumes has been performed in order to isolate strains resistant to cadmium ions in a wide range of concentrations (6-132 mg/kg). The effect ofcadmium salts (6, 12, 24 mg/kg) on the legume-rhizobium symbiosis ofthe pea Pisum sativum L. with Rhizobium leguminosarum and of the fodder galega Galega orientalis Lam. with Rhizobium galegae has been studied under experimental laboratory conditions. No statistically significant differences have been revealed in the growth and biomass of plants with regard to the control in the range of concentrations given above. However, it was found that cadmium inhibited nodulation in P. sativum and stimulated it in G. orientalis.

  10. Transcriptional regulators of legume-rhizobia symbiosis: nuclear factors Ys and GRAS are two for tango.

    Science.gov (United States)

    Rípodas, Carolina; Clúa, Joaquín; Battaglia, Marina; Baudin, Maël; Niebel, Andreas; Zanetti, María Eugenia; Blanco, Flavio

    2014-01-01

    Transcription factors are DNA binding proteins that regulate gene expression. The nitrogen fixing symbiosis established between legume plants and soil bacteria is a complex interaction, in which plants need to integrate signals derived from the symbiont and the surrounding environment to initiate the developmental program of nodule organogenesis and the infection process. Several transcription factors that play critical roles in these processes have been reported in the past decade, including proteins of the GRAS and NF-Y families. Recently, we reported the characterization of a new GRAS domain containing-protein that interacts with a member of the C subunit of the NF-Y family, which plays an important role in nodule development and the progression of bacterial infection during the symbiotic interaction. The connection between transcription factors of these families highlights the significance of multimeric complexes in the fabulous capacity of plants to integrate and respond to multiple environmental stimuli.

  11. Isolation of Rhizobium Bacteria from Forage Legumes for the Development of Ruminant Feed

    Science.gov (United States)

    Fuskhah, E.; Purbajanti, E. D.; Anwar, S.

    2018-02-01

    The aimed of the study was to explore the presence of Rhizobium bacteria along the northern coast of Central Java, to develop a saline-resistant legumes. Rhizobium bacteria is a mutualistic bacterium capable of symbiosis with legumes so that legumes crop yields increase. The research begins with sampling of soil and root nodule of forage legumes along the Northern Coast of Central Java including Tegal, Pekalongan, Semarang, Demak, Pati. Soil samples were analysed for salinity, Total Dissolved Solids, and pH. Rhizobium bacteria were isolated from the acquired root nodule, then identified by biochemical test to ensure that the isolates obtained were Rhizobium bacteria. The results showed that the five districts/municipal sites sampled by the soil have very low salinity to very high levels. The highest level of soil salinity was found in Demak (Sayung) which has an electrical conductivity value (EC) of 17.77 mmhos/cm. The EC values of legumes overgrown soils showed a low salinity level while bare soils have high salinity levels. Feed crops legumes that could be found in the northern coast of Central Java were Centrosema pubescens, Calopogonium mucunoides, Leucaena leucocephala, and Sesbania grandiflora. The study obtained 6 kinds of isolates of rhizobium bacteria isolated from forage legumes, included 1) Centrosema pubescens isolated from Pekalongan, 2) Centrosema pubescens isolated from Tegal, 3) Calopogonium mucunoides isolated from Pekalongan, 4) Leucaenaleucocephala isolated from Tegal, 5) Leucaena leucocephala isolated from Semarang, 6) Sesbania grandiflora isolated from Tegal.

  12. Dissecting the Root Nodule Transcriptome of Chickpea (Cicer arietinum L..

    Directory of Open Access Journals (Sweden)

    Chandra Kant

    Full Text Available A hallmark trait of chickpea (Cicer arietinum L., like other legumes, is the capability to convert atmospheric nitrogen (N2 into ammonia (NH3 in symbiotic association with Mesorhizobium ciceri. However, the complexity of molecular networks associated with the dynamics of nodule development in chickpea need to be analyzed in depth. Hence, in order to gain insights into the chickpea nodule development, the transcriptomes of nodules at early, middle and late stages of development were sequenced using the Roche 454 platform. This generated 490.84 Mb sequence data comprising 1,360,251 reads which were assembled into 83,405 unigenes. Transcripts were annotated using Gene Ontology (GO, Cluster of Orthologous Groups (COG and Kyoto Encyclopedia of Genes and Genomes (KEGG metabolic pathways analysis. Differential expression analysis revealed that a total of 3760 transcripts were differentially expressed in at least one of three stages, whereas 935, 117 and 2707 transcripts were found to be differentially expressed in the early, middle and late stages of nodule development respectively. MapMan analysis revealed enrichment of metabolic pathways such as transport, protein synthesis, signaling and carbohydrate metabolism during root nodulation. Transcription factors were predicted and analyzed for their differential expression during nodule development. Putative nodule specific transcripts were identified and enriched for GO categories using BiNGO which revealed many categories to be enriched during nodule development, including transcription regulators and transporters. Further, the assembled transcriptome was also used to mine for genic SSR markers. In conclusion, this study will help in enriching the transcriptomic resources implicated in understanding of root nodulation events in chickpea.

  13. Dissecting the Root Nodule Transcriptome of Chickpea (Cicer arietinum L.).

    Science.gov (United States)

    Kant, Chandra; Pradhan, Seema; Bhatia, Sabhyata

    2016-01-01

    A hallmark trait of chickpea (Cicer arietinum L.), like other legumes, is the capability to convert atmospheric nitrogen (N2) into ammonia (NH3) in symbiotic association with Mesorhizobium ciceri. However, the complexity of molecular networks associated with the dynamics of nodule development in chickpea need to be analyzed in depth. Hence, in order to gain insights into the chickpea nodule development, the transcriptomes of nodules at early, middle and late stages of development were sequenced using the Roche 454 platform. This generated 490.84 Mb sequence data comprising 1,360,251 reads which were assembled into 83,405 unigenes. Transcripts were annotated using Gene Ontology (GO), Cluster of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways analysis. Differential expression analysis revealed that a total of 3760 transcripts were differentially expressed in at least one of three stages, whereas 935, 117 and 2707 transcripts were found to be differentially expressed in the early, middle and late stages of nodule development respectively. MapMan analysis revealed enrichment of metabolic pathways such as transport, protein synthesis, signaling and carbohydrate metabolism during root nodulation. Transcription factors were predicted and analyzed for their differential expression during nodule development. Putative nodule specific transcripts were identified and enriched for GO categories using BiNGO which revealed many categories to be enriched during nodule development, including transcription regulators and transporters. Further, the assembled transcriptome was also used to mine for genic SSR markers. In conclusion, this study will help in enriching the transcriptomic resources implicated in understanding of root nodulation events in chickpea.

  14. Paraquat Toxicity on Root Nodule Formation on Macroptiliuma Tropurpureum Urb. and Its Corelation with Population of Rhizobium SP.

    OpenAIRE

    Martani, Erni; Margino, Sebastian; Magdalena, Medhina

    2004-01-01

    This study was designed to investigate the paraquat toxicity toward root nodulation by Rhizobium on Macroptilium atropurpureum as an indicator plant. The legume was grown in Thornton medium treated with several concentrations of paraquat and inoculated with R.japonicum 143 (Rj-143) or Rhizobium sp. C-1.1. These bacteria represent cross-inoculation of soybean and cover-crops legumes, respectively. Nodule formation and Rhizobium population were measured periodically. At the end of planting time...

  15. A Legume TOR Protein Kinase Regulates Rhizobium Symbiosis and Is Essential for Infection and Nodule Development1[OPEN

    Science.gov (United States)

    Blanco, Lourdes; Quinto, Carmen

    2016-01-01

    The target of rapamycin (TOR) protein kinase regulates metabolism, growth, and life span in yeast, animals, and plants in coordination with nutrient status and environmental conditions. The nutrient-dependent nature of TOR functionality makes this kinase a putative regulator of symbiotic associations involving nutrient acquisition. However, TOR’s role in these processes remains to be understood. Here, we uncovered the role of TOR during the bean (Phaseolus vulgaris)-Rhizobium tropici (Rhizobium) symbiotic interaction. TOR was expressed in all tested bean tissues, with higher transcript levels in the root meristems and senesced nodules. We showed TOR promoter expression along the progressing infection thread and in the infected cells of mature nodules. Posttranscriptional gene silencing of TOR using RNA interference (RNAi) showed that this gene is involved in lateral root elongation and root cell organization and also alters the density, size, and number of root hairs. The suppression of TOR transcripts also affected infection thread progression and associated cortical cell divisions, resulting in a drastic reduction of nodule numbers. TOR-RNAi resulted in reduced reactive oxygen species accumulation and altered CyclinD1 and CyclinD3 expression, which are crucial factors for infection thread progression and nodule organogenesis. Enhanced expression of TOR-regulated ATG genes in TOR-RNAi roots suggested that TOR plays a role in the recognition of Rhizobium as a symbiont. Together, these data suggest that TOR plays a vital role in the establishment of root nodule symbiosis in the common bean. PMID:27698253

  16. Synthesis of Rhizobial Exopolysaccharides and Their Importance for Symbiosis with Legume Plants

    Directory of Open Access Journals (Sweden)

    Małgorzata Marczak

    2017-12-01

    Full Text Available Rhizobia dwell and multiply in the soil and represent a unique group of bacteria able to enter into a symbiotic interaction with plants from the Fabaceae family and fix atmospheric nitrogen inside de novo created plant organs, called nodules. One of the key determinants of the successful interaction between these bacteria and plants are exopolysaccharides, which represent species-specific homo- and heteropolymers of different carbohydrate units frequently decorated by non-carbohydrate substituents. Exopolysaccharides are typically built from repeat units assembled by the Wzx/Wzy-dependent pathway, where individual subunits are synthesized in conjunction with the lipid anchor undecaprenylphosphate (und-PP, due to the activity of glycosyltransferases. Complete oligosaccharide repeat units are transferred to the periplasmic space by the activity of the Wzx flippase, and, while still being anchored in the membrane, they are joined by the polymerase Wzy. Here we have focused on the genetic control over the process of exopolysaccharides (EPS biosynthesis in rhizobia, with emphasis put on the recent advancements in understanding the mode of action of the key proteins operating in the pathway. A role played by exopolysaccharide in Rhizobium–legume symbiosis, including recent data confirming the signaling function of EPS, is also discussed.

  17. [Signaling Systems of Rhizobia (Rhizobiaceae) and Leguminous Plants (Fabaceae) upon the Formation of a Legume-Rhizobium Symbiosis (Review)].

    Science.gov (United States)

    Glyan'ko, A K

    2015-01-01

    Data from the literature and our own data on the participation and interrelation of bacterial signaling Nod-factors and components of the calcium, NADPH-oxidase, and NO-synthase signaling systems of a plant at the preinfection and infectious stages of the formation of a legume-rhizobium symbiosis are summarized in this review. The physiological role of Nod-factors, reactive oxygen species (ROS), calcium (Ca2+), NADPH-oxidase, nitric oxide (NO), and their cross influence on the processes determining the formation of symbiotic structures on the roots of the host plant is discussed.

  18. Computational investigation of small RNAs in the establishment of root nodules and arbuscular mycorrhiza in leguminous plants.

    Science.gov (United States)

    Jin, Danfeng; Meng, Xianwen; Wang, Yue; Wang, Jingjing; Zhao, Yuhua; Chen, Ming

    2018-01-03

    Many small RNAs have been confirmed to play important roles in the development of root nodules and arbuscular mycorrhiza. In this study, we carried out the identification of certain small RNAs in leguminous plants (Medicago truncatula, soybean, peanut and common bean), such as miRNAs, tRFs and srRNAs, as well as the computational investigation of their regulations. Thirty miRNAs were predicted to be involved in establishing root nodules and mycorrhiza, and 12 of them were novel in common bean and peanut. The generation of tRFs in M. truncatula was not associated with tRNA gene frequencies and codon usage. Six tRFs exhibited different expressions in mycorrhiza and root nodules. Moreover, srRNA 5.8S in M. truncatula was generated from the regions with relatively low conservation at the rRNA 3' terminal. The protein-protein interactions between the proteins encoded by the target genes of miRNAs, tRFs and srRNAs were computed. The regulation of these three types of sRNAs in the symbiosis between leguminous plants and microorganisms is not a single regulation of certain signaling or metabolic pathways but a global regulation for the plants to own growth or specific events in symbiosis.

  19. GC-MS based metabolite profiling implies three interdependent ways of ammonium assimilation in Medicago truncatula root nodules.

    Science.gov (United States)

    Barsch, Aiko; Carvalho, Helena G; Cullimore, Julie V; Niehaus, Karsten

    2006-12-15

    In symbiotic interaction with legume plants, bacteria termed Rhizobia can fix massive amounts of atmospheric nitrogen which is primarily provided in the form of ammonium to the host plants. Therefore, legume root nodules that house the symbiotic bacteria are ideally suited to study the process of primary ammonium assimilation. Here, we present a GC-MS based metabolite profiling analysis of Medicago truncatula root nodules (induced by the bacterium Sinorhizobium meliloti) before and after inhibition of glutamine synthetase (GS) by the chemical herbicide phosphinotricine. The primary role of GS in ammonium assimilation was revealed by drastically reduced levels of glutamine in phosphinotricine treated root nodules. In comparison to previous results of increased asparagine synthetase transcript and protein abundances in GS inhibited nodules the metabolic data revealed that decreased amounts of aspartate might preclude taking advantage of this elevated enzymatic activity. A potential role of glutamate dehydrogenase in ammonium assimilation was metabolically indicated 24 and 48 h after GS inhibition. Therefore, nodule ammonium assimilation might in principle involve three interdependent metabolic pathways which are adjusted to control basic nitrogen metabolism.

  20. Schoolyard Symbiosis.

    Science.gov (United States)

    Allard, David W.

    1996-01-01

    Discusses different types of symbiosis--mutualism, commensalism, and parasitism--and examples of each type including lichens, legumes, mistletoe, and epiphytes. Describes how teachers can use these examples in the study of symbiosis which allows teachers to focus on many basic concepts in evolution, cell biology, ecology, and other fields of…

  1. Transcriptome Analysis of Paraburkholderia phymatum under Nitrogen Starvation and during Symbiosis with Phaseolus Vulgaris

    Directory of Open Access Journals (Sweden)

    Martina Lardi

    2017-12-01

    Full Text Available Paraburkholderia phymatum belongs to the β-subclass of proteobacteria. It has recently been shown to be able to nodulate and fix nitrogen in symbiosis with several mimosoid and papilionoid legumes. In contrast to the symbiosis of legumes with α-proteobacteria, very little is known about the molecular determinants underlying the successful establishment of this mutualistic relationship with β-proteobacteria. In this study, we performed an RNA-sequencing (RNA-seq analysis of free-living P. phymatum growing under nitrogen-replete and -limited conditions, the latter partially mimicking the situation in nitrogen-deprived soils. Among the genes upregulated under nitrogen limitation, we found genes involved in exopolysaccharides production and in motility, two traits relevant for plant root infection. Next, RNA-seq data of P. phymatum grown under free-living conditions and from symbiotic root nodules of Phaseolus vulgaris (common bean were generated and compared. Among the genes highly upregulated during symbiosis, we identified—besides the nif gene cluster—an operon encoding a potential cytochrome o ubiquinol oxidase (Bphy_3646-49. Bean root nodules induced by a cyoB mutant strain showed reduced nitrogenase and nitrogen fixation abilities, suggesting an important role of the cytochrome for respiration inside the nodule. The analysis of mutant strains for the RNA polymerase transcription factor RpoN (σ54 and its activator NifA indicated that—similar to the situation in α-rhizobia—P. phymatum RpoN and NifA are key regulators during symbiosis with P. vulgaris.

  2. Common bean-Rhizobium symbiosis: functional genomics of legume response to abiotic stresses

    Science.gov (United States)

    Common bean (Phaseolus vulgaris) is the world's most important grain legume for direct human consumption and a main source of proteins in Latin America and Africa. Environmental factors such as nutrient deficiency, soil acidity, and metal toxicity are important constraints for bean symbiotic nitroge...

  3. Effects of water stress on the rooting, nodulation potentials and ...

    African Journals Online (AJOL)

    Rooting, nodulation and growth ability of cowpea growing under limited water supply was investigated at the Teaching and Research Farm of the Imo State University, Owerri, Nigeria. The experiment was conducted in plastic buckets arranged in a completely Randomized Design with three replications, and treatments ...

  4. Root-nodule bacteria isolated from native Amphithalea ericifolia and ...

    African Journals Online (AJOL)

    Indigenous root-nodule bacteria isolated from the acid sands of the Cape using Aspalathus linearis, Aspalathus hispida, Aspalathus carnosa, Aspalathus capensis and Amphithalea ericifolia as trap hosts showed considerable tolerance to low pH. Isolates from A. ericifolia and A. carnosa could even grow in YMB medium at ...

  5. Rhizobium-legume symbiosis in the absence of Nod factors: two possible scenarios with or without the T3SS.

    Science.gov (United States)

    Okazaki, Shin; Tittabutr, Panlada; Teulet, Albin; Thouin, Julien; Fardoux, Joël; Chaintreuil, Clémence; Gully, Djamel; Arrighi, Jean-François; Furuta, Noriyuki; Miwa, Hiroki; Yasuda, Michiko; Nouwen, Nico; Teaumroong, Neung; Giraud, Eric

    2016-01-01

    The occurrence of alternative Nod factor (NF)-independent symbiosis between legumes and rhizobia was first demonstrated in some Aeschynomene species that are nodulated by photosynthetic bradyrhizobia lacking the canonical nodABC genes. In this study, we revealed that a large diversity of non-photosynthetic bradyrhizobia, including B. elkanii, was also able to induce nodules on the NF-independent Aeschynomene species, A. indica. Using cytological analysis of the nodules and the nitrogenase enzyme activity as markers, a gradient in the symbiotic interaction between bradyrhizobial strains and A. indica could be distinguished. This ranged from strains that induced nodules that were only infected intercellularly to rhizobial strains that formed nodules in which the host cells were invaded intracellularly and that displayed a weak nitrogenase activity. In all non-photosynthetic bradyrhizobia, the type III secretion system (T3SS) appears required to trigger nodule organogenesis. In contrast, genome sequence analysis revealed that apart from a few exceptions, like the Bradyrhizobium ORS285 strain, photosynthetic bradyrhizobia strains lack a T3SS. Furthermore, analysis of the symbiotic properties of an ORS285 T3SS mutant revealed that the T3SS could have a positive or negative role for the interaction with NF-dependent Aeschynomene species, but that it is dispensable for the interaction with all NF-independent Aeschynomene species tested. Taken together, these data indicate that two NF-independent symbiotic processes are possible between legumes and rhizobia: one dependent on a T3SS and one using a so far unknown mechanism.

  6. Anatomy and ultrastructure of root nodules of Lupinus luteus

    Directory of Open Access Journals (Sweden)

    A. Woźny

    2015-01-01

    Full Text Available The paper presents anatomic structure of root nodules of lupine (Lupinus luteus L. cv. Express and ultrastructure of cells infected by Rhizobium, The inside of cells from the infected nodule region was filled with numerous bacteria; only centrally located cell nucleus was free of bacteria. Rhizobium was present mostly in the form of "transforming bacteria" (according to the terminology by Ching et al. 1977, characterized by visible nucleoid areas, numerous ribosomes, and polyphosphate granules, although typical bacterioids with poly-β-hydroxybutyrate were also found.

  7. Heart of endosymbioses: transcriptomics reveals a conserved genetic program among arbuscular mycorrhizal, actinorhizal and legume-rhizobial symbioses.

    Directory of Open Access Journals (Sweden)

    Alexandre Tromas

    Full Text Available To improve their nutrition, most plants associate with soil microorganisms, particularly fungi, to form mycorrhizae. A few lineages, including actinorhizal plants and legumes are also able to interact with nitrogen-fixing bacteria hosted intracellularly inside root nodules. Fossil and molecular data suggest that the molecular mechanisms involved in these root nodule symbioses (RNS have been partially recycled from more ancient and widespread arbuscular mycorrhizal (AM symbiosis. We used a comparative transcriptomics approach to identify genes involved in establishing these 3 endosymbioses and their functioning. We analysed global changes in gene expression in AM in the actinorhizal tree C. glauca. A comparison with genes induced in AM in Medicago truncatula and Oryza sativa revealed a common set of genes induced in AM. A comparison with genes induced in nitrogen-fixing nodules of C. glauca and M. truncatula also made it possible to define a common set of genes induced in these three endosymbioses. The existence of this core set of genes is in accordance with the proposed recycling of ancient AM genes for new functions related to nodulation in legumes and actinorhizal plants.

  8. Rhizobium pongamiae sp. nov. from root nodules of Pongamia pinnata.

    Science.gov (United States)

    Kesari, Vigya; Ramesh, Aadi Moolam; Rangan, Latha

    2013-01-01

    Pongamia pinnata has an added advantage of N2-fixing ability and tolerance to stress conditions as compared with other biodiesel crops. It harbours "rhizobia" as an endophytic bacterial community on its root nodules. A gram-negative, nonmotile, fast-growing, rod-shaped, bacterial strain VKLR-01(T) was isolated from root nodules of Pongamia that grew optimal at 28°C, pH 7.0 in presence of 2% NaCl. Isolate VKLR-01 exhibits higher tolerance to the prevailing adverse conditions, for example, salt stress, elevated temperatures and alkalinity. Strain VKLR-01(T) has the major cellular fatty acid as C(18:1) ω7c (65.92%). Strain VKLR-01(T) was found to be a nitrogen fixer using the acetylene reduction assay and PCR detection of a nifH gene. On the basis of phenotypic, phylogenetic distinctiveness and molecular data (16S rRNA, recA, and atpD gene sequences, G + C content, DNA-DNA hybridization etc.), strain VKLR-01(T) = (MTCC 10513(T) = MSCL 1015(T)) is considered to represent a novel species of the genus Rhizobium for which the name Rhizobium pongamiae sp. nov. is proposed. Rhizobium pongamiae may possess specific traits that can be transferred to other rhizobia through biotechnological tools and can be directly used as inoculants for reclamation of wasteland; hence, they are very important from both economic and environmental prospects.

  9. A Proteomic Approach of Bradyrhizobium/Aeschynomene Root and Stem Symbioses Reveals the Importance of the fixA Locus for Symbiosis

    Directory of Open Access Journals (Sweden)

    Nathanael Delmotte

    2014-02-01

    Full Text Available Rhizobia are soil bacteria that are able to form symbiosis with plant hosts of the legume family. These associations result in the formation of organs, called nodules in which bacteria fix atmospheric nitrogen to the benefit of the plant. Most of our knowledge on the metabolism and the physiology of the bacteria during symbiosis derives from studying roots nodules of terrestrial plants. Here we used a proteomics approach to investigate the bacterial physiology of photosynthetic Bradyrhizobium sp. ORS278 during the symbiotic process with the semi aquatical plant Aeschynomene indica that forms root and stem nodules. We analyzed the proteomes of bacteria extracted from each type of nodule. First, we analyzed the bacteroid proteome at two different time points and found only minor variation between the bacterial proteomes of 2-week- and 3-week-old nodules. High conservation of the bacteroid proteome was also found when comparing stem nodules and root nodules. Among the stem nodule specific proteins were those related to the phototrophic ability of Bradyrhizobium sp. ORS278. Furthermore, we compared our data with those obtained during an extensive genetic screen previously published. The symbiotic role of four candidate genes which corresponding proteins were found massively produced in the nodules but not identified during this screening was examined. Mutant analysis suggested that in addition to the EtfAB system, the fixA locus is required for symbiotic efficiency.

  10. Nitrogen fixation and carbon metabolism in legume nodules.

    Science.gov (United States)

    Garg, Neera; Singla, Ranju; Geetanjali

    2004-02-01

    A large amount of energy is utilized by legume nodules for the fixation of nitrogen and assimilation of fixed nitrogen (ammonia) into organic compounds. The source of energy is provided in the form of photosynthates by the host plant. Phosphoenol pyruvate carboxylase (PEPC) enzyme, which is responsible for carbon dioxide fixation in C4 and crassulacean acid metabolism plants, has also been found to play an important role in carbon metabolism in legume root nodule. PEPC-mediated CO2 fixation in nodules results in the synthesis of C4 dicarboxylic acids, viz. aspartate, malate, fumarate etc. which can be transported into bacteroids with the intervention of dicarboxylate transporter (DCT) protein. PEPC has been purified from the root nodules of few legume species. Information on the relationship between nitrogen fixation and carbon metabolism through PEPC in leguminous plants is scanty and incoherent. This review summarizes the various aspects of carbon and nitrogen metabolism in legume root nodules.

  11. In situ localization of chalcone synthase mRNA in pea root nodule development.

    NARCIS (Netherlands)

    Yang, W.C.; Canter Cremers, H.C.J.; Hogendijk, P.; Katinakis, P.; Wijffelman, C.A.; Franssen, H.J.; Kammen, van A.; Bisseling, T.

    1992-01-01

    In this paper studies on the role of flavonoids in pea root nodule development are reported. Flavonoid synthesis was followed by localizing chalcone synthase (CHS) mRNA in infected pea roots and in root nodules. In a nodule primordium, CHS mRNA is present in all cells of the primordium. Therefore it

  12. Proteomic insights into intra- and intercellular plant-bacteria symbiotic association during root nodule formation

    Directory of Open Access Journals (Sweden)

    Afshin eSalavati

    2013-02-01

    Full Text Available Over the last several decades, there have been a large number of studies done on the all aspects of legumes and bacteria which participate in nitrogen-fixing symbiosis. The analysis of legume-bacteria interaction is not just a matter of numerical complexity in terms of variants of gene products that can arise from a single gene. Bacteria regulate their quorum-sensing genes to enhance their ability to induce conjugation of plasmids and symbiotic islands, and various protein secretion mechanisms; that can stimulate a collection of chain reactions including species-specific combinations of plant-secretion isoflavonoids, complicated calcium signaling pathways and autoregulation of nodulation mechanisms. Quorum-sensing systems are introduced by the intra- and intercellular organization of gene products lead to protein–protein interactions or targeting of proteins to specific cellular structures. In this study, an attempt has been made to review significant contributions related to nodule formation and development and their impacts on cell proteome for better understanding of plant-bacterium interaction mechanism at protein level. This review would not only provide new insights into the plant-bacteria symbiosis response mechanisms but would also highlights the importance of studying changes in protein abundance inside and outside of cells in response to symbiosis. Furthermore, the application to agriculture programe of plant-bacteria interaction will be discussed.

  13. Comparative phylogenetic and expression analysis of small GTPases families in legume and non-legume plants.

    Science.gov (United States)

    Flores, Ana Claudia; Via, Virginia Dalla; Savy, Virginia; Villagra, Ulises Mancini; Zanetti, María Eugenia; Blanco, Flavio

    2018-02-01

    Small monomeric GTPases act as molecular switches in several processes that involve polar cell growth, participating mainly in vesicle trafficking and cytoskeleton rearrangements. This gene superfamily has largely expanded in plants through evolution as compared with other Kingdoms, leading to the suggestion that members of each subfamily might have acquired new functions associated to plant-specific processes. Legume plants engage in a nitrogen-fixing symbiotic interaction with rhizobia in a process that involves polar growth processes associated with the infection throughout the root hair. To get insight into the evolution of small GTPases associated with this process, we use a comparative genomic approach to establish differences in the Ras GTPase superfamily between legume and non-legume plants. Phylogenetic analyses did not show clear differences in the organization of the different subfamilies of small GTPases between plants that engage or not in nodule symbiosis. Protein alignments revealed a strong conservation at the sequence level of small GTPases previously linked to nodulation by functional genetics. Interestingly, one Rab and three Rop proteins showed conserved amino acid substitutions in legumes, but these changes do not alter the predicted conformational structure of these proteins. Although the steady-state levels of most small GTPases do not change in response to rhizobia, we identified a subset of Rab, Rop and Arf genes whose transcript levels are modulated during the symbiotic interaction, including their spatial distribution along the indeterminate nodule. This study provides a comprehensive study of the small GTPase superfamily in several plant species. The genetic program associated to root nodule symbiosis includes small GTPases to fulfill specific functions during infection and formation of the symbiosomes. These GTPases seems to have been recruited from members that were already present in common ancestors with plants as distant as monocots

  14. Evolution of rhizobium symbiosis

    NARCIS (Netherlands)

    Camp, Op den R.H.M.

    2012-01-01

    The evolution of rhizobium symbiosis is studied from several points of view in this thesis. The ultimate goal of the combined approaches is to unravel the genetic constrains of the symbiotic interaction. To this end the legume rhizobium symbiosis is studied in model plant species from the

  15. Evolution of rhizobium symbiosis

    NARCIS (Netherlands)

    Camp, Op den R.H.M.

    2012-01-01

    The evolution of rhizobium symbiosis is studied from several points of view in this thesis. The ultimate goal of the combined approaches is to unravel the genetic constrains of the symbiotic interaction. To this end the legume rhizobium symbiosis is studied in model plant species from the

  16. Bradyrhizobium ottawaense sp. nov., a symbiotic nitrogen fixing bacterium from root nodules of soybeans in Canada.

    Science.gov (United States)

    Yu, Xiumei; Cloutier, Sylvie; Tambong, James T; Bromfield, Eden S P

    2014-09-01

    Sixteen strains of symbiotic bacteria from root nodules of Glycine max grown in Ottawa, Canada, were previously characterized and placed in a novel group within the genus Bradyrhizobium. To verify their taxonomic status, these strains were further characterized using a polyphasic approach. All strains possessed identical 16S rRNA gene sequences that were 99.79 % similar to the closest relative, Bradyrhizobium liaoningense LMG 18230(T). Phylogenetic analysis of concatenated atpD, glnII, recA, gyrB, rpoB and dnaK genes divided the 16 strains into three multilocus sequence types that were placed in a highly supported lineage distinct from named species of the genus Bradyrhizobium consistent with results of DNA-DNA hybridization. Based on analysis of symbiosis gene sequences (nodC and nifH), all novel strains were placed in a phylogenetic group with five species of the genus Bradyrhizobium that nodulate soybeans. The combination of phenotypic characteristics from several tests including carbon and nitrogen source utilization and antibiotic resistance could be used to differentiate representative strains from recognized species of the genus Bradyrhizobium. Novel strain OO99(T) elicits effective nodules on Glycine max, Glycine soja and Macroptilium atropurpureum, partially effective nodules on Desmodium canadense and Vigna unguiculata, and ineffective nodules on Amphicarpaea bracteata and Phaseolus vulgaris. Based on the data presented, we conclude that our strains represent a novel species for which the name Bradyrhizobium ottawaense sp. nov. is proposed, with OO99(T) ( = LMG 26739(T) = HAMBI 3284(T)) as the type strain. The DNA G+C content is 62.6 mol%. © 2014 Her Majesty the Queen in right of Canada as represented by the Minister of AAFC.

  17. Bradyrhizobium ottawaense sp. nov., a symbiotic nitrogen fixing bacterium from root nodules of soybeans in Canada

    Science.gov (United States)

    Yu, Xiumei; Cloutier, Sylvie; Tambong, James T.

    2014-01-01

    Sixteen strains of symbiotic bacteria from root nodules of Glycine max grown in Ottawa, Canada, were previously characterized and placed in a novel group within the genus Bradyrhizobium. To verify their taxonomic status, these strains were further characterized using a polyphasic approach. All strains possessed identical 16S rRNA gene sequences that were 99.79 % similar to the closest relative, Bradyrhizobium liaoningense LMG 18230T. Phylogenetic analysis of concatenated atpD, glnII, recA, gyrB, rpoB and dnaK genes divided the 16 strains into three multilocus sequence types that were placed in a highly supported lineage distinct from named species of the genus Bradyrhizobium consistent with results of DNA–DNA hybridization. Based on analysis of symbiosis gene sequences (nodC and nifH), all novel strains were placed in a phylogenetic group with five species of the genus Bradyrhizobium that nodulate soybeans. The combination of phenotypic characteristics from several tests including carbon and nitrogen source utilization and antibiotic resistance could be used to differentiate representative strains from recognized species of the genus Bradyrhizobium. Novel strain OO99T elicits effective nodules on Glycine max, Glycine soja and Macroptilium atropurpureum, partially effective nodules on Desmodium canadense and Vigna unguiculata, and ineffective nodules on Amphicarpaea bracteata and Phaseolus vulgaris. Based on the data presented, we conclude that our strains represent a novel species for which the name Bradyrhizobium ottawaense sp. nov. is proposed, with OO99T ( = LMG 26739T = HAMBI 3284T) as the type strain. The DNA G+C content is 62.6 mol%. PMID:24969302

  18. Final Report Grant No. DE-FG02-98ER20307 Lipopolysaccharide Structures and Genes Required for Root Nodule Development August 1, 2004 to July 31, 2008

    Energy Technology Data Exchange (ETDEWEB)

    Noel, K. Dale [Marquette Univ., Milwaukee,WI (United States)

    2008-12-07

    This project dealt with the plant-bacterial symbiosis that gives rise to root nodules on leguminous plants in which the bacteria carry out nitrogen fixation. Nitrogen fixation, like carbon dioxide fixation, is essential for life on planet earth, and this symbiosis is estimated to account for half of all nitrogen fixed on land. Aside from being important for the sustenance of global life, this ability allows legumes to grow without nitrogen fertilizers. Basic studies such as this project are aimed at understanding the symbiosis well enough that eventually it can be engineered into important crop species so that they no longer depend on nitrogen fertilizer for growth. The production and distribution of excessive fertilizer needed for optimal crop yields is responsible for a significant portion of the energy costs in agriculture. The specific aims of this work were to further the understanding of a bacterial factor that is essential for the symbiotic infection process. This factor is a bacterial surface molecule, lipopolysaccharide O antigen. In this project we showed that, not only the presence, but the specific structure of this molecule is crucial for infection. Although the success of bacterial infections in many pathogenic and mutualistic interactions have been shown to depend on intact O antigen, it has been very rare to establish that specific features of the structure are important. One of the features in this case is the presence of one additional methyl group on one sugar in the O antigen. It is very surprising that such a minor change should have an observable effect. This work sets the stage for biochemical studies of possible plant receptors that may be involved. During the course of this grant period, we developed a method of testing the importance of this bacterial component at stages of nodule development beyond the step that is blocked by null mutation. The method works adequately for this purpose and is being improved. It has implications for testing

  19. Asparagine Biosynthesis in Alfalfa (Medicago sativa L.) Root Nodules.

    Science.gov (United States)

    Snapp, S S; Vance, C P

    1986-10-01

    Rapid direct conversion of exogenously supplied [(14)C]aspartate to [(14)C] asparagine and to tricarboxylic cycle acids was observed in alfalfa (Medicago sativa L.) nodules. Aspartate aminotransferase activity readily converted carbon from exogenously applied [(14)C]aspartate into the tricarboxylic acid cycle with subsequent conversion to the organic acids malate, succinate, and fumarate. Aminooxyacetate, an inhibitor of aminotransferase activity, reduced the flow of carbon from [(14)C]aspartate into tricarboxylic cycle acids and decreased (14)CO(2) evolution by 99%. Concurrently, maximum conversion of aspartate to asparagine was observed in aminooxyacetate treated nodules (30 nanomoles asparagine per gram fresh weight per hour. Metabolism of [(14)C]aspartate and distribution of nodulefixed (14)CO(2) suggest that two pools of aspartate occur in alfalfa nodules: (a) one involved in asparagine biosynthesis, and (b) another supplying a malate/aspartate shuttle. Conversion of [(14)C]aspartate to [(14)C]asparagine was not inhibited by methionine sulfoximine, a glutamine synthetase inhibitor, or azaserine, a glutmate synthetase, inhibitor. The data did not indicate that asparagine biosynthesis in alfalfa nodules has an absolute requirement for glutamine. Radioactivity in the xylem sap, derived from nodule (14)CO(2) fixation, was markedly decreased by treating nodulated roots with aminooxyacetate, methionine sulfoximine, and azaserine. Inhibitors decreased the [(14)C]aspartate and [(14)]asparagine content of xylem sap by greater than 80% and reduced the total amino nitrogen content of xylem sap (including nonradiolabeled amino acids) by 50 to 80%. Asparagine biosynthesis in alfalfa nodules and transport in xylem sap are dependent upon continued aminotransferase activity and an uninterrupted assimilation of ammonia via the glutamine synthetase/glutamate synthase pathway. Continued assimilation of ammonia apparently appears crucial to continued root nodule CO(2) fixation in

  20. Bacterial-induced calcium oscillations are common to nitrogen-fixing associations of nodulating legumes and non-legumes

    NARCIS (Netherlands)

    Granqvist, E.; Sun, J.; Camp, Op den R.; Pujic, P.; Hill, L.; Normand, P.; Morris, R.J.; Downie, J.A.; Geurts, R.; Oldroyd, G.E.D.

    2015-01-01

    •Plants that form root-nodule symbioses are within a monophyletic ‘nitrogen-fixing’ clade and associated signalling processes are shared with the arbuscular mycorrhizal symbiosis. Central to symbiotic signalling are nuclear-associated oscillations in calcium ions (Ca2+), occurring in the root hairs

  1. Paraquat Toxicity on Root Nodule Formation on Macroptiliuma tropurpureum Urb. and Its Corelation with Population of Rhizobium sp.

    Directory of Open Access Journals (Sweden)

    Erni Martani

    2004-12-01

    Full Text Available This study was designed to investigate the paraquat toxicity toward root nodulation by Rhizobium on Macroptilium atropurpureum as an indicator plant. The legume was grown in Thornton medium treated with several concentrations of paraquat and inoculated with R.japonicum 143 (Rj-143 or Rhizobium sp. C-1.1. These bacteria represent cross-inoculation of soybean and cover-crops legumes, respectively. Nodule formation and Rhizobium population were measured periodically. At the end of planting time, nitrogenase activity of the nodules was analysis based on ARA (Acethylene Reduction Analysis method. The results showed that nodules in plants inoculated with Rhizobium without addition paraquat, were formed within four weeks. There was no nodulation when paraquat was added. Paraquat was toxic to the plant, causing chlorosis, stunting, drying of the plant tissues, and death. The symptoms were detected at the second week after planting time. Paraquat also decreased Rhizobium population from 10^6 to 10^2 or 10^1 CFU/mL at 40 and 100 pp, respectively. These results depicted that paraquat disturbed the plant before nodulation, and at the same time Rhizobium populatin decreased until below minimal population required for nodulation. Therefore, the process of nodulation was disturbed, and in some treatments there was nodulation. It was concluded that paraquat was toxic to both plant and the Rhizobium, which cause nodulation failure.

  2. Effect of cropping systems and arbuscular mycorrhizal fungi on soil microbial activity and root nodule nitrogenase

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Zarea

    2011-06-01

    Full Text Available Forage legumes are used to enhancement soil fertility of the agro ecosystem. Understanding effect of them on agro ecosystem soil status during when these legumes growing and after that is essential. In one experiment the effects of inoculation with the arbuscular mycorrhizal fungi (AMF, Glomus mosseae, and mixed cropping systems (MCS on forage biomass yield, nitrogen production, nitrogenase activity and after harvesting on soil microbial activity were studied at various mixed cropping ratios of berseem clover (Trifolium alexandrinum L., B to Persian clover (Trifolium resupinatum L., P (B:P = 1:0, 3:1, 1:1, and 1:3. In the second experiment, the effect of treatments on soil microbial activity were studied by soil collection after clover harvesting and 8-week soil incubations in the laboratory. MCS had positive effects on root and shoot dry weight. The effects of AMF on plant yield were positive. AMF affected the fraction root and the vertical root distribution. Plants colonized by AMF showed shorter roots than control plants. At cut 1, with the AMF colonization, the greatest nitrogenase activity (79.61 μmol C2H4 g dwt−1 h−1 of root nodule was observed with B:P = 3:1. At cut 2, the Persian clover plants colonized by G. mosseae in the mixed crop (1:3 had a higher nitrogenase activity (77.38 μmol C2H4 g dwt−1 h−1. The greatest nitrogen accumulation in the aboveground biomass, 23.5 mg g−1 forage dry matter, was obtained with mixed cropping (B:P = 1:1 in the presence of the AMF colonization. Microbial activity measured as substrate-induced respiration and activities of dehydrogenase, alkaline phosphatase, and acid phosphatase enzymes responded positively to AMF colonization; with the greatest activities for B:P = 1:3.

  3. Growth conditions determine the DNF2 requirement for symbiosis.

    Directory of Open Access Journals (Sweden)

    Fathi Berrabah

    Full Text Available Rhizobia and legumes are able to interact in a symbiotic way leading to the development of root nodules. Within nodules, rhizobia fix nitrogen for the benefit of the plant. These interactions are efficient because spectacularly high densities of nitrogen fixing rhizobia are maintained in the plant cells. DNF2, a Medicago truncatula gene has been described as required for nitrogen fixation, bacteroid's persistence and to prevent defense-like reactions in the nodules. This manuscript shows that a Rhizobium mutant unable to differentiate is not sufficient to trigger defense-like reactions in this organ. Furthermore, we show that the requirement of DNF2 for effective symbiosis can be overcome by permissive growth conditions. The dnf2 knockout mutants grown in vitro on agarose or Phytagel as gelling agents are able to produce nodules fixing nitrogen with the same efficiency as the wild-type. However, when agarose medium is supplemented with the plant defense elicitor ulvan, the dnf2 mutant recovers the fix- phenotype. Together, our data show that plant growth conditions impact the gene requirement for symbiotic nitrogen fixation and suggest that they influence the symbiotic suppression of defense reactions in nodules.

  4. Sucrose synthase and enolase expression in actinorhizal nodules of Alnus glutinosa: comparison with legume nodules.

    NARCIS (Netherlands)

    Ghelue, van M.; Ribeiro, A.; Solheim, B.; Akkermans, A.D.L.; Bisseling, T.; Pawlowski, K.

    1996-01-01

    Abstract Two different types of nitrogen-fixing root nodules are known - actinorhizal nodules induced by Frankia and legume nodules induced by rhizobia. While legume nodules show a stem-like structure with peripheral vascular bundles, actinorhizal nodule lobes resemble modified lateral roots with a

  5. Leguminous plants: inventors of root nodules to accommodate symbiotic bacteria.

    Science.gov (United States)

    Suzaki, Takuya; Yoro, Emiko; Kawaguchi, Masayoshi

    2015-01-01

    Legumes and a few other plant species can establish a symbiotic relationship with nitrogen-fixing rhizobia, which enables them to survive in a nitrogen-deficient environment. During the course of nodulation, infection with rhizobia induces the dedifferentiation of host cells to form primordia of a symbiotic organ, the nodule, which prepares plants to accommodate rhizobia in host cells. While these nodulation processes are known to be genetically controlled by both plants and rhizobia, recent advances in studies on two model legumes, Lotus japonicus and Medicago truncatula, have provided great insight into the underlying plant-side molecular mechanism. In this chapter, we review such knowledge, with particular emphasis on two key processes of nodulation, nodule development and rhizobial invasion. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Root-nodule bacteria isolated from native Amphithalea ericifolia and ...

    African Journals Online (AJOL)

    Yomi

    2012-01-26

    Jan 26, 2012 ... and Graham, 1991; Foster, 1993; Del Papa et al., 2003;. Kiss et al., 2004; Draghi et al., 2010). In the Cape flats and Cederberg mountains of South. Africa, the soils are extremely high in acidity, ranging from. pH 2.9 to 5.0 (Muofhe and Dakora, 1998); yet they support growth of many native legumes as well ...

  7. The independent acquisition of plant root nitrogen-fixing symbiosis in Fabids recruited the same genetic pathway for nodule organogenesis.

    Directory of Open Access Journals (Sweden)

    Sergio Svistoonoff

    Full Text Available Only species belonging to the Fabid clade, limited to four classes and ten families of Angiosperms, are able to form nitrogen-fixing root nodule symbioses (RNS with soil bacteria. This concerns plants of the legume family (Fabaceae and Parasponia (Cannabaceae associated with the Gram-negative proteobacteria collectively called rhizobia and actinorhizal plants associated with the Gram-positive actinomycetes of the genus Frankia. Calcium and calmodulin-dependent protein kinase (CCaMK is a key component of the common signaling pathway leading to both rhizobial and arbuscular mycorrhizal symbioses (AM and plays a central role in cross-signaling between root nodule organogenesis and infection processes. Here, we show that CCaMK is also needed for successful actinorhiza formation and interaction with AM fungi in the actinorhizal tree Casuarina glauca and is also able to restore both nodulation and AM symbioses in a Medicago truncatula ccamk mutant. Besides, we expressed auto-active CgCCaMK lacking the auto-inhibitory/CaM domain in two actinorhizal species: C. glauca (Casuarinaceae, which develops an intracellular infection pathway, and Discaria trinervis (Rhamnaceae which is characterized by an ancestral intercellular infection mechanism. In both species, we found induction of nodulation independent of Frankia similar to response to the activation of CCaMK in the rhizobia-legume symbiosis and conclude that the regulation of actinorhiza organogenesis is conserved regardless of the infection mode. It has been suggested that rhizobial and actinorhizal symbioses originated from a common ancestor with several independent evolutionary origins. Our findings are consistent with the recruitment of a similar genetic pathway governing rhizobial and Frankia nodule organogenesis.

  8. The Independent Acquisition of Plant Root Nitrogen-Fixing Symbiosis in Fabids Recruited the Same Genetic Pathway for Nodule Organogenesis

    Science.gov (United States)

    Svistoonoff, Sergio; Benabdoun, Faiza Meriem; Nambiar-Veetil, Mathish; Imanishi, Leandro; Vaissayre, Virginie; Cesari, Stella; Diagne, Nathalie; Hocher, Valérie; de Billy, Françoise; Bonneau, Jocelyne; Wall, Luis; Ykhlef, Nadia; Rosenberg, Charles; Bogusz, Didier; Franche, Claudine; Gherbi, Hassen

    2013-01-01

    Only species belonging to the Fabid clade, limited to four classes and ten families of Angiosperms, are able to form nitrogen-fixing root nodule symbioses (RNS) with soil bacteria. This concerns plants of the legume family (Fabaceae) and Parasponia (Cannabaceae) associated with the Gram-negative proteobacteria collectively called rhizobia and actinorhizal plants associated with the Gram-positive actinomycetes of the genus Frankia. Calcium and calmodulin-dependent protein kinase (CCaMK) is a key component of the common signaling pathway leading to both rhizobial and arbuscular mycorrhizal symbioses (AM) and plays a central role in cross-signaling between root nodule organogenesis and infection processes. Here, we show that CCaMK is also needed for successful actinorhiza formation and interaction with AM fungi in the actinorhizal tree Casuarina glauca and is also able to restore both nodulation and AM symbioses in a Medicago truncatula ccamk mutant. Besides, we expressed auto-active CgCCaMK lacking the auto-inhibitory/CaM domain in two actinorhizal species: C. glauca (Casuarinaceae), which develops an intracellular infection pathway, and Discaria trinervis (Rhamnaceae) which is characterized by an ancestral intercellular infection mechanism. In both species, we found induction of nodulation independent of Frankia similar to response to the activation of CCaMK in the rhizobia-legume symbiosis and conclude that the regulation of actinorhiza organogenesis is conserved regardless of the infection mode. It has been suggested that rhizobial and actinorhizal symbioses originated from a common ancestor with several independent evolutionary origins. Our findings are consistent with the recruitment of a similar genetic pathway governing rhizobial and Frankia nodule organogenesis. PMID:23741336

  9. Smallholder farmers' use and profitability of legume inoculants in ...

    African Journals Online (AJOL)

    The area under the crop, distance to local markets, knowledge of legume root nodules, education level, contacts with organisations promoting biological N fixation (BNF) technologies, group membership, soybean market and location of the farm based on agro-ecological zone were factors that determine the use of the ...

  10. Characterization of root-nodulating bacteria associated to Prosopis farcta growing in the arid regions of Tunisia.

    Science.gov (United States)

    Fterich, A; Mahdhi, M; Caviedes, M A; Pajuelo, E; Rivas, R; Rodriguez-Llorente, I D; Mars, M

    2011-06-01

    Diversity of 50 bacterial isolates recovered from root nodules of Prosopis farcta grown in different arid soils in Tunisia, was investigated. Characterization of isolates was assessed using a polyphasic approach including phenotypic characteristics, 16S rRNA gene PCR--RFLP and sequencing, nodA gene sequencing and MLSA. It was found that most of isolates are tolerant to high temperature (40°C) and salinity (3%). Genetic characterization emphasizes that isolates were assigned to the genus Ensifer (80%), Mesorhizobium (4%) and non-nodulating endophytic bacteria (16%). Forty isolates belonging to the genus Ensifer were affiliated to Ensifer meliloti, Ensifer xinjiangense/Ensifer fredii and Ensifer numidicus species. Two isolates belonged to the genus Mesorhizobium. Eight isolates failing to renodulate their host plant were endophytic bacteria and belonged to Bacillus, Paenibacillus and Acinetobacter genera. Symbiotic properties of nodulating isolates showed a diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Isolate PG29 identified as Ensifer meliloti was the most effective one. Ability of Prosopis farcta to establish symbiosis with rhizobial species confers an important advantage for this species to be used in reforestation programs. This study offered the first systematic information about the diversity of microsymbionts nodulating Prosopis farcta in the arid regions of Tunisia.

  11. Nitrogen transfer in the interface between the symbionts in pea root nodules

    DEFF Research Database (Denmark)

    Rosendahl, L.; Mouritzen, P.; Rudbeck, A.

    2001-01-01

    Transport mechanisms for transfer of nitrogen from the bacteroid side across the symbiosome membrane of pea (Pisum sativum L.) root nodules were identified by the use of energised bacteroid side-out symbiosome membrane vesicles. Such membrane vesicles were used to study a mechanism with high...... was not observed. The ammonium transporter has been identified as a voltage-driven channel whereas the symbiosome membrane aspartate transporter appears to be a H+/aspartate symport. The results suggest that nitrogen transfer between the symbionts in pea root nodules involves transfer of amino acids as well...

  12. Growth behaviour and bioproduction of indole acetic acid by a Rhizobium sp. isolated from root nodules of a leguminous tree Dalbergia lanceolaria.

    Science.gov (United States)

    Ghosh, A C; Basu, P S

    2002-07-01

    The Rhizobium sp. isolated from healthy and mature root nodules of a leguminous tree, Dalbergia lanceolaria Linn. f., preferred mannitol and KNO3 for growth as carbon and nitrogen sources, respectively. The bacterium produced a high amount (22.3 microg/ml) of indole acetic acid (IAA) from L-tryptophan supplemented basal medium. Growth and IAA production started simultaneously. IAA production was maximum at 20 hr when the bacteria reached the stationary phase of growth. Cultural requirements were optimized for maximum growth and IAA production. The IAA production by the Rhizobium sp. was increased by 270.8% over control when the medium was supplemented with mannitol (1%,w/v), SDS (1 microg/ml), L-asparagine (0.02%,w/v) and biotin (1 microg/ml) in addition to L-tryptophan (2.5 mg/ml). The possible role of IAA production in the symbiosis is discussed.

  13. Infection and invasion of roots by symbiotic, nitrogen-fixing rhizobia during nodulation of temperate legumes.

    Science.gov (United States)

    Gage, Daniel J

    2004-06-01

    Bacteria belonging to the genera Rhizobium, Mesorhizobium, Sinorhizobium, Bradyrhizobium, and Azorhizobium (collectively referred to as rhizobia) grow in the soil as free-living organisms but can also live as nitrogen-fixing symbionts inside root nodule cells of legume plants. The interactions between several rhizobial species and their host plants have become models for this type of nitrogen-fixing symbiosis. Temperate legumes such as alfalfa, pea, and vetch form indeterminate nodules that arise from root inner and middle cortical cells and grow out from the root via a persistent meristem. During the formation of functional indeterminate nodules, symbiotic bacteria must gain access to the interior of the host root. To get from the outside to the inside, rhizobia grow and divide in tubules called infection threads, which are composite structures derived from the two symbiotic partners. This review focuses on symbiotic infection and invasion during the formation of indeterminate nodules. It summarizes root hair growth, how root hair growth is influenced by rhizobial signaling molecules, infection of root hairs, infection thread extension down root hairs, infection thread growth into root tissue, and the plant and bacterial contributions necessary for infection thread formation and growth. The review also summarizes recent advances concerning the growth dynamics of rhizobial populations in infection threads.

  14. Metabolomic Profiling of Bradyrhizobium diazoefficiens-Induced Root Nodules Reveals Both Host Plant-Specific and Developmental Signatures

    Directory of Open Access Journals (Sweden)

    Martina Lardi

    2016-05-01

    Full Text Available Bradyrhizobium diazoefficiens is a nitrogen-fixing endosymbiont, which can grow inside root-nodule cells of the agriculturally important soybean and other host plants. Our previous studies described B. diazoefficiens host-specific global expression changes occurring during legume infection at the transcript and protein level. In order to further characterize nodule metabolism, we here determine by flow injection–time-of-flight mass spectrometry analysis the metabolome of (i nodules and roots from four different B. diazoefficiens host plants; (ii soybean nodules harvested at different time points during nodule development; and (iii soybean nodules infected by two strains mutated in key genes for nitrogen fixation, respectively. Ribose (soybean, tartaric acid (mungbean, hydroxybutanoyloxybutanoate (siratro and catechol (cowpea were among the metabolites found to be specifically elevated in one of the respective host plants. While the level of C4-dicarboxylic acids decreased during soybean nodule development, we observed an accumulation of trehalose-phosphate at 21 days post infection (dpi. Moreover, nodules from non-nitrogen-fixing bacteroids (nifA and nifH mutants showed specific metabolic alterations; these were also supported by independent transcriptomics data. The alterations included signs of nitrogen limitation in both mutants, and an increased level of a phytoalexin in nodules induced by the nifA mutant, suggesting that the tissue of these nodules exhibits defense and stress reactions.

  15. Contribution of NFP LysM domains to the recognition of Nod factors during the Medicago truncatula/Sinorhizobium meliloti symbiosis.

    Science.gov (United States)

    Bensmihen, Sandra; de Billy, Françoise; Gough, Clare

    2011-01-01

    The root nodule nitrogen fixing symbiosis between legume plants and soil bacteria called rhizobia is of great agronomical and ecological interest since it provides the plant with fixed atmospheric nitrogen. The establishment of this symbiosis is mediated by the recognition by the host plant of lipo-chitooligosaccharides called Nod Factors (NFs), produced by the rhizobia. This recognition is highly specific, as precise NF structures are required depending on the host plant. Here, we study the importance of different LysM domains of a LysM-Receptor Like Kinase (LysM-RLK) from Medicago truncatula called Nod factor perception (NFP) in the recognition of different substitutions of NFs produced by its symbiont Sinorhizobium meliloti. These substitutions are a sulphate group at the reducing end, which is essential for host specificity, and a specific acyl chain at the non-reducing end, that is critical for the infection process. The NFP extracellular domain (ECD) contains 3 LysM domains that are predicted to bind NFs. By swapping the whole ECD or individual LysM domains of NFP for those of its orthologous gene from pea, SYM10 (a legume plant that interacts with another strain of rhizobium producing NFs with different substitutions), we showed that NFP is not directly responsible for specific recognition of the sulphate substitution of S. meliloti NFs, but probably interacts with the acyl substitution. Moreover, we have demonstrated the importance of the NFP LysM2 domain for rhizobial infection and we have pinpointed the importance of a single leucine residue of LysM2 in that step of the symbiosis. Together, our data put into new perspective the recognition of NFs in the different steps of symbiosis in M. truncatula, emphasising the probable existence of a missing component for early NF recognition and reinforcing the important role of NFP for NF recognition during rhizobial infection.

  16. Contribution of NFP LysM domains to the recognition of Nod factors during the Medicago truncatula/Sinorhizobium meliloti symbiosis.

    Directory of Open Access Journals (Sweden)

    Sandra Bensmihen

    Full Text Available The root nodule nitrogen fixing symbiosis between legume plants and soil bacteria called rhizobia is of great agronomical and ecological interest since it provides the plant with fixed atmospheric nitrogen. The establishment of this symbiosis is mediated by the recognition by the host plant of lipo-chitooligosaccharides called Nod Factors (NFs, produced by the rhizobia. This recognition is highly specific, as precise NF structures are required depending on the host plant. Here, we study the importance of different LysM domains of a LysM-Receptor Like Kinase (LysM-RLK from Medicago truncatula called Nod factor perception (NFP in the recognition of different substitutions of NFs produced by its symbiont Sinorhizobium meliloti. These substitutions are a sulphate group at the reducing end, which is essential for host specificity, and a specific acyl chain at the non-reducing end, that is critical for the infection process. The NFP extracellular domain (ECD contains 3 LysM domains that are predicted to bind NFs. By swapping the whole ECD or individual LysM domains of NFP for those of its orthologous gene from pea, SYM10 (a legume plant that interacts with another strain of rhizobium producing NFs with different substitutions, we showed that NFP is not directly responsible for specific recognition of the sulphate substitution of S. meliloti NFs, but probably interacts with the acyl substitution. Moreover, we have demonstrated the importance of the NFP LysM2 domain for rhizobial infection and we have pinpointed the importance of a single leucine residue of LysM2 in that step of the symbiosis. Together, our data put into new perspective the recognition of NFs in the different steps of symbiosis in M. truncatula, emphasising the probable existence of a missing component for early NF recognition and reinforcing the important role of NFP for NF recognition during rhizobial infection.

  17. Identification of Ononitol and O-methyl-scyllo-inositol in Pea Root Nodules

    DEFF Research Database (Denmark)

    Skøt, Leif; Egsgaard, Helge

    1984-01-01

    Ononitol (4-O-methyl-myo-inositol) and O-methyl-scyllo-inositol were identified in pea (Pisum sativum L.) root nodules formed by twoRhizobium leguminosarum strains. Ononitol was the major soluble carbohydrate in nodules formed by strain 1045 while O-methyl-scyllo-inositol and two unidentified com...

  18. Isolation and characterization of the heavy metal resistant bacteria CCNWRS33-2 isolated from root nodule of Lespedeza cuneata in gold mine tailings in China

    International Nuclear Information System (INIS)

    Wei Gehong; Fan Lianmei; Zhu Wenfei; Fu Yunyun; Yu Jianfu; Tang Ming

    2009-01-01

    A total of 108 strains of bacteria were isolated from root nodules of wild legumes growing in gold mine tailings in northwest of China and were tested for heavy metal resistance. The results showed that the bacterial strain CCNWRS33-2 isolated from Lespedeza cuneata was highly resistant to copper, cadmium, lead and zinc. The strain had a relatively high mean specific growth rate under each heavy metal stress test and exhibited a high degree of bioaccumulation ability. The partial sequence of the copper resistance gene copA was amplified from the strain and a sequence comparison with our Cu-resistant PCR fragment showed a high homology with Cu-resistant genes from other bacteria. Phylogenetic analysis based on the 16S rRNA gene sequence showed that CCNWRS33-2 belongs to the Rhizobium-Agrobacterium branch and it had 98.9% similarity to Agrobactrium tumefaciens LMG196

  19. Isolation and characterization of the heavy metal resistant bacteria CCNWRS33-2 isolated from root nodule of Lespedeza cuneata in gold mine tailings in China

    Energy Technology Data Exchange (ETDEWEB)

    Wei Gehong [College of Life Science, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A and F University, Yangling Shaanxi 712100 (China)], E-mail: weigehong@yahoo.com.cn; Fan Lianmei; Zhu Wenfei; Fu Yunyun; Yu Jianfu; Tang Ming [College of Life Science, Shaanxi Key Laboratory of Molecular Biology for Agriculture, Northwest A and F University, Yangling Shaanxi 712100 (China)

    2009-02-15

    A total of 108 strains of bacteria were isolated from root nodules of wild legumes growing in gold mine tailings in northwest of China and were tested for heavy metal resistance. The results showed that the bacterial strain CCNWRS33-2 isolated from Lespedeza cuneata was highly resistant to copper, cadmium, lead and zinc. The strain had a relatively high mean specific growth rate under each heavy metal stress test and exhibited a high degree of bioaccumulation ability. The partial sequence of the copper resistance gene copA was amplified from the strain and a sequence comparison with our Cu-resistant PCR fragment showed a high homology with Cu-resistant genes from other bacteria. Phylogenetic analysis based on the 16S rRNA gene sequence showed that CCNWRS33-2 belongs to the Rhizobium-Agrobacterium branch and it had 98.9% similarity to Agrobactrium tumefaciens LMG196.

  20. Diversity of root nodule bacteria from leguminous crops

    Directory of Open Access Journals (Sweden)

    Agrawal Pooja

    2016-01-01

    Full Text Available In the present study, a total of 353 nodule-associated bacteria were isolated from 220 legume plant samples belonging to Cicer arietinum (85, Glycine max (74, Vigna radiata (21 and Cajanus cajan (40. A total of 224 bacteria were identified as fast-growing Rhizobium spp. on the basis of differential staining (Gram staining and carbol fuchsin staining and biochemical tests. All the isolates were tested for indole acetic acid production (IAA, phosphate solubilization and siderophore production on plate assay. To examine the effect of volatile organic metabolites (VOM and water soluble soil components (WSSC on nodule bacteria, culture conditions were optimized by observing the effects of various parameters such as pH, salt content and temperatures on the growth of bacteria. Selected rhizobia were subjected to random amplified polymorphic DNA (RAPD and amplified ribosomal DNA restriction analysis (ARDRA analysis to identify their species. On the basis of RAPD and ARDRA, 10 isolates were identified as Rhizobium meliloti. In this study, Rhizobium GO4, G16, G20, G77, S43, S81, M07, M37, A15 and A55 were observed as the best candidates among the tested bacteria and can be further used as potent bioinoculants.

  1. Thiol-based redox signaling in the nitrogen-fixing symbiosis

    Directory of Open Access Journals (Sweden)

    Pierre eFrendo

    2013-09-01

    Full Text Available In nitrogen poor soils legumes establish a symbiotic interaction with rhizobia that results in the formation of root nodules. These are unique plant organs where bacteria differentiate into bacteroids, which express the nitrogenase enzyme complex that reduces atmospheric N2 to ammonia. Nodule metabolism requires a tight control of the concentrations of reactive oxygen and nitrogen species (RONS so that they can perform useful signaling roles while avoiding nitro-oxidative damage. In nodules a thiol-dependent regulatory network that senses, transmits and responds to redox changes is starting to be elucidated. A combination of enzymatic, immunological, pharmacological and molecular analyses has allowed to conclude that glutathione and its legume-specific homolog, homoglutathione, are abundant in meristematic and infected cells, their spatio-temporally distribution is correlated with the corresponding (homoglutathione synthetase activities, and are crucial for nodule development and function. Glutathione is at high concentrations in the bacteroids and at moderate amounts in the mitochondria, cytosol and nuclei. Less information is available on other components of the network. The expression of multiple isoforms of glutathione peroxidases, peroxiredoxins, thioredoxins, glutaredoxins and NADPH-thioredoxin reductases has been detected in nodule cells using antibodies and proteomics. Peroxiredoxins and thioredoxins are essential to regulate and in some cases to detoxify RONS in nodules. Further research is necessary to clarify the regulation of the expression and activity of thiol redox-active proteins in response to abiotic, biotic and developmental cues, their interactions with downstream targets by disulfide-exchange reactions, and their participation in signaling cascades. The availability of mutants and transgenic lines will be crucial to facilitate systematic investigations into the function of the various proteins in the legume

  2. Studies on legume root hair development : correlations with the infection process by Rhizobium bacteria

    NARCIS (Netherlands)

    Mylona, P.

    1996-01-01


    Rhizobia-legume interaction leading to the formation of specific organs, namely root nodules, starts at the epidermis of the root. Bacteria interfere with the develomental programme of the epidermal cells by inducing a number of responses, as new root hair growth, root hair deformation

  3. Diversity and numbers of root-nodule bacteria (rhizobia in Polish soils

    Directory of Open Access Journals (Sweden)

    Stefan Martyniuk

    2011-01-01

    Full Text Available Using a sand pouch-plant infection method, populations of several species of root-nodule bacteria (rhizobia were enumerated in eighty soils collected throughout Poland. Rhizobium leguminosarum bv. viciae (symbionts of pea, faba bean, vetch and R. leguminosarum bv. trifolii (symbionts of clover were detected in 77 and 76 soils, respectively. Most of these soils contained moderate and high numbers of these species of the rhizobia. Symbionts of beans, R. leguminosarum bv. phaseoli, were assessed in 76 soils; of this number 15 soils had no detectable populations of bean rhizobia and in 40 soils high or moderate numbers of these bacteria were found. Bradyrhizobium sp. (Lupinus, root-nodule bacteria of lupine and serradella, were absent in 19 soils, out of 80 tested, and 34 soils were colonised by high or moderate populations of bradyrhizobia. Sinorhizobium meliloti, rhizobia nodulating alfalfa, were sparse in the examined soils; with 56 soil containing no detectable numbers of S. meliloti and only 6 soils harbouring high or moderate populations of this species. The estimated numbers of the rhizobia in the studied soils were also related to some physical and chemical properties of these soils.

  4. How legumes recognize rhizobia.

    Science.gov (United States)

    Via, Virginia Dalla; Zanetti, María Eugenia; Blanco, Flavio

    2016-01-01

    Legume plants have developed the capacity to establish symbiotic interactions with soil bacteria (known as rhizobia) that can convert N2 to molecular forms that are incorporated into the plant metabolism. The first step of this relationship is the recognition of bacteria by the plant, which allows to distinguish potentially harmful species from symbiotic partners. The main molecular determinant of this symbiotic interaction is the Nod Factor, a diffusible lipochitooligosaccharide molecule produced by rhizobia and perceived by LysM receptor kinases; however, other important molecules involved in the specific recognition have emerged over the years. Secreted exopolysaccharides and the lipopolysaccharides present in the bacterial cell wall have been proposed to act as signaling molecules, triggering the expression of specific genes related to the symbiotic process. In this review we will briefly discuss how transcriptomic analysis are helping to understand how multiple signaling pathways, triggered by the perception of different molecules produced by rhizobia, control the genetic programs of root nodule organogenesis and bacterial infection. This knowledge can help to understand how legumes have evolved to recognize and establish complex ecological relationships with particular species and strains of rhizobia, adjusting gene expression in response to identity determinants of bacteria.

  5. Localization of acid phosphatase activity in the apoplast of root nodules of pea (Pisum sativum

    Directory of Open Access Journals (Sweden)

    Marzena Sujkowska

    2011-01-01

    Full Text Available Changes in the activity of acid phosphatase (AcPase in the apoplast of pea root nodule were investigated. The activity was determined using lead and cerium methods. The results indicated a following sequence of AcPase activity appearance during the development of the infection thread: 1 low AcPase activity appears in the outer part of cells of symbiotic bacteria; 2 bacteria show increased AcPase activity, and the enzyme activity appears in the thread walls; 3 activity exhibits also matrix of the infection thread; 4 bacteria just before their release from the infection threads show high AcPase activity; 5 AcPase activity ceases after bacteria transformation into bacteroids. The increase in bacterial AcPase activity may reflect a higher demand for inorganic phosphorus necessary for propagation of the bacteria within the infection threads and/or involved in bacteria release from the infection threads.

  6. Rhizobium favelukesii sp. nov., isolated from the root nodules of alfalfa (Medicago sativa L).

    Science.gov (United States)

    Torres Tejerizo, Gonzalo; Rogel, Marco Antonio; Ormeño-Orrillo, Ernesto; Althabegoiti, María Julia; Nilsson, Juliet Fernanda; Niehaus, Karsten; Schlüter, Andreas; Pühler, Alfred; Del Papa, María Florencia; Lagares, Antonio; Martínez-Romero, Esperanza; Pistorio, Mariano

    2016-11-01

    Strains LPU83T and Or191 of the genus Rhizobium were isolated from the root nodules of alfalfa, grown in acid soils from Argentina and the USA. These two strains, which shared the same plasmid pattern, lipopolysaccharide profile, insertion-sequence fingerprint, 16S rRNA gene sequence and PCR-fingerprinting pattern, were different from reference strains representing species of the genus Rhizobium with validly published names. On the basis of previously reported data and from new DNA-DNA hybridization results, phenotypic characterization and phylogenetic analyses, strains LPU83T and Or191 can be considered to be representatives of a novel species of the genus Rhizobium, for which the name Rhizobium favelukesii sp. nov. is proposed. The type strain of this species is LPU83T (=CECT 9014T=LMG 29160T), for which an improved draft-genome sequence is available.

  7. Ensifer shofinae sp. nov., a novel rhizobial species isolated from root nodules of soybean (Glycine max).

    Science.gov (United States)

    Chen, Wen Hao; Yang, Sheng Hui; Li, Zhao Hu; Zhang, Xiao Xia; Sui, Xin Hua; Wang, En Tao; Chen, Wen Xin; Chen, Wen Feng

    2017-04-01

    Two bacterial strains isolated from root nodules of soybean were characterized phylogenetically as members of a distinct group in the genus Ensifer based on 16S rRNA gene comparisons. They were also verified as a separated group by the concatenated sequence analyses of recA, atpD and glnII (with similarities ≤93.9% to the type strains for defined species), and by the average nucleotide identities (ANI) between the whole genome sequence of the representative strain CCBAU 251167 T and those of the closely related strains in Ensifer glycinis and Ensifer fredii (90.5% and 90.3%, respectively). Phylogeny of symbiotic genes (nodC and nifH) grouped these two strains together with some soybean-nodulating strains of E. fredii, E. glycinis and Ensifer sojae. Nodulation tests indicated that the representative strain CCBAU 251167 T could form root nodules with capability of nitrogen fixing on its host plant and Glycine soja, Cajanus cajan, Vigna unguiculata, Phaseolus vulgaris and Astragalus membranaceus, and it formed ineffective nodules on Leucaena leucocephala. Strain CCBAU 251167 T contained fatty acids 18:1 ω9c, 18:0 iso and 20:0, differing from other related strains. Utilization of l-threonine and d-serine as carbon source, growth at pH 6.0 and intolerance of 1% (w/v) NaCl distinguished strain CCBAU 251167 T from other type strains of the related species. The genome size of CCBAU 251167 T was 6.2Mbp, comprising 7,581 predicted genes with DNA G+C content of 59.9mol% and 970 unique genes. Therefore, a novel species, Ensifer shofinae sp. nov., is proposed, with CCBAU 251167 T (=ACCC 19939 T =LMG 29645 T ) as type strain. Copyright © 2017 Elsevier GmbH. All rights reserved.

  8. Diversity of Frankia populations in root nodules of geographically isolated Arizona alder trees in central Arizona (United States)

    Science.gov (United States)

    Allana K. Welsh; Jeffrey O. Dawson; Gerald J. Gottfried; Dittmar Hahn

    2009-01-01

    The diversity of uncultured Frankia populations in root nodules of Alnus oblongifolia trees geographically isolated on mountaintops of central Arizona was analyzed by comparative sequence analyses of nifH gene fragments. Sequences were retrieved from Frankia populations in nodules of four trees from each of...

  9. Type 3 Secretion System (T3SS) ofBradyrhizobiumsp. DOA9 and Its Roles in Legume Symbiosis and Rice Endophytic Association.

    Science.gov (United States)

    Songwattana, Pongpan; Noisangiam, Rujirek; Teamtisong, Kamonluck; Prakamhang, Janpen; Teulet, Albin; Tittabutr, Panlada; Piromyou, Pongdet; Boonkerd, Nantakorn; Giraud, Eric; Teaumroong, Neung

    2017-01-01

    The Bradyrhizobium sp. DOA9 strain isolated from a paddy field has the ability to nodulate a wide spectrum of legumes. Unlike other bradyrhizobia, this strain has a symbiotic plasmid harboring nod , nif , and type 3 secretion system (T3SS) genes. This T3SS cluster contains all the genes necessary for the formation of the secretory apparatus and the transcriptional activator (TtsI), which is preceded by a nod -box motif. An in silico search predicted 14 effectors putatively translocated by this T3SS machinery. In this study, we explored the role of the T3SS in the symbiotic performance of DOA9 by evaluating the ability of a T3SS mutant (Ω rhcN ) to nodulate legumes belonging to Dalbergioid, Millettioid, and Genistoid tribes. Among the nine species tested, four ( Arachis hypogea , Vigna radiata , Crotalaria juncea , and Macroptilium atropurpureum ) responded positively to the rhcN mutation (ranging from suppression of plant defense reactions, an increase in the number of nodules and a dramatic improvement in nodule development and infection), one ( Stylosanthes hamata ) responded negatively (fewer nodules and less nitrogen fixation) and four species ( Aeschynomene americana , Aeschynomene afraspera , Indigofera tinctoria , and Desmodium tortuosum ) displayed no phenotype. We also tested the role of the T3SS in the ability of the DOA9 strain to endophytically colonize rice roots, but detected no effect of the T3SS mutation, in contrast to what was previously reported in the Bradyrhizobium SUTN9-2 strain. Taken together, these data indicate that DOA9 contains a functional T3SS that interferes with the ability of the strain to interact symbiotically with legumes but not with rice.

  10. An overview of the metabolic differences between Bradyrhizobium japonicum 110 bacteria and differentiated bacteroids from soybean (Glycine max) root nodules: an in vitro 13C- and 31P-nuclear magnetic resonance spectroscopy study

    International Nuclear Information System (INIS)

    Vauclare, Pierre; Bligny, Richard; Gout, Elisabeth; Widmer, Francois

    2013-01-01

    Bradyrhizobium japonicum is a symbiotic nitrogen-fixing soil bacteria that induce root nodules formation in legume soybean (Glycine max.). Using 13 C- and 31 P-nuclear magnetic resonance (NMR) spectroscopy, we have analysed the metabolite profiles of cultivated B. japonicum cells and bacteroids isolated from soybean nodules. Our results revealed some quantitative and qualitative differences between the metabolite profiles of bacteroids and their vegetative state. This includes in bacteroids a huge accumulation of soluble carbohydrates such as trehalose, glutamate, myo-inositol and homo-spermidine as well as Pi, nucleotide pools and intermediates of the primary carbon metabolism. Using this novel approach, these data show that most of the compounds detected in bacteroids reflect the metabolic adaptation of rhizobia to the surrounding microenvironment with its host plant cells. (authors)

  11. Symbiotic leghemoglobins are crucial for nitrogen fixation in legume root nodules but not for general plant growth and development

    DEFF Research Database (Denmark)

    Ott, Thomas; van Dongen, Joost T; Günther, Catrin

    2005-01-01

    Hemoglobins are ubiquitous in nature and among the best-characterized proteins. Genetics has revealed crucial roles for human hemoglobins, but similar data are lacking for plants. Plants contain symbiotic and nonsymbiotic hemoglobins; the former are thought to be important for symbiotic nitrogen...... accumulate to millimolar concentrations in the cytoplasm of infected plant cells prior to nitrogen fixation and are thought to buffer free oxygen in the nanomolar range, avoiding inactivation of oxygen-labile nitrogenase while maintaining high oxygen flux for respiration. Although widely accepted......RNAi plants grew normally when fertilized with mineral nitrogen. These data indicate roles for leghemoglobins in oxygen transport and buffering and prove for the first time that plant hemoglobins are crucial for symbiotic nitrogen fixation. Udgivelsesdato: 2005-Mar-29...

  12. Physiological roles of glutathione s-transferases in soybean root nodules.

    Science.gov (United States)

    Dalton, David A; Boniface, Chris; Turner, Zachary; Lindahl, Amy; Kim, Hyeon Jeong; Jelinek, Laura; Govindarajulu, Manjula; Finger, Richard E; Taylor, Christopher G

    2009-05-01

    Glutathione S-transferases (GSTs) are ubiquitous enzymes that catalyze the conjugation of toxic xenobiotics and oxidatively produced compounds to reduced glutathione, which facilitates their metabolism, sequestration, or removal. We report here that soybean (Glycine max) root nodules contain at least 14 forms of GST, with GST9 being most prevalent, as measured by both real-time reverse transcription-polymerase chain reaction and identification of peptides in glutathione-affinity purified extracts. GST8 was prevalent in stems and uninfected roots, whereas GST2/10 prevailed in leaves. Purified, recombinant GSTs were shown to have wide-ranging kinetic properties, suggesting that the suite of GSTs could provide physiological flexibility to deal with numerous stresses. Levels of GST9 increased with aging, suggesting a role related to senescence. RNA interference studies of nodules on composite plants showed that a down-regulation of GST9 led to a decrease in nitrogenase (acetylene reduction) activity and an increase in oxidatively damaged proteins. These findings indicate that GSTs are abundant in nodules and likely function to provide antioxidant defenses that are critical to support nitrogen fixation.

  13. Bacillus radicibacter sp. nov., a new bacterium isolated from root nodule of Oxytropis ochrocephala Bunge.

    Science.gov (United States)

    Wei, Xiu Li; Lin, Yan Bing; Xu, Lin; Han, Meng Sha; Dong, Dan Hong; Chen, Wei Min; Wang, Li; Wei, Ge Hong

    2015-10-01

    A Gram-positive, facultative anaerobic, rod-shaped, and endospore-forming strain, designated 53-2(T) was isolated from the root nodule of Oxytropis ochrocephala Bunge growing on Qilian mountain, China. The strain can grow at pH 7.0-8.0, 10-50 °C and tolerate up to 11% NaCl. Optimal growth occurred at pH 7.2 and 37 °C. The result of BLASTn search based on 16S rRNA gene sequence revealed that strain 53-2(T) , being closest related to Bacillus acidicola 105-2(T) , possessed remote similarity (less than 95.64%) to the species within genus Bacillus. The DNA G + C content was 37.8%. Chemotaxonomic data (major quinone is MK-7; major polar lipids are diphosphatidylglycerol, phosphatidylglycerol, unknown phospholipid, and aminoglycophospholipid; fatty acids are anteiso-C15: 0 , iso-C15:0 and anteiso-C17: 0 ) supported the affiliation of the isolate to the genus Bacillus. On the basis of physiological, phylogenetic, and biochemical properties, strain 53-2(T) represents a novel species within genus Bacillus, for which the name Bacillus radicibacter is proposed. The type strain is 53-2(T) (=DSM27302(T) =ACCC06115(T) =CCNWQLS5(T) ). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Industrial symbiosis

    DEFF Research Database (Denmark)

    Sacchi, Romain; Remmen, Arne

    2017-01-01

    This study examines the development of industrial symbiosis through a practical model for physical, organizational, and social interactions in six different cases from around the world. The results provide a framework that can be used by industrial symbiosis practitioners to facilitate the creation...... of synergy in industrial areas....

  15. Rhizobium taibaishanense sp. nov., isolated from a root nodule of Kummerowia striata.

    Science.gov (United States)

    Yao, Li Juan; Shen, Yao Yao; Zhan, Jun Peng; Xu, Wei; Cui, Guang Ling; Wei, Ge Hong

    2012-02-01

    During a study of the diversity and phylogeny of rhizobia in the root nodules of Kummerowia striata grown in north-western China, four strains were classified in the genus Rhizobium on the basis of their 16S rRNA gene sequences. The 16S rRNA gene sequences of three of these strains were identical and that of the other strain, which was the only one isolated in Yangling, differed from the others by just 1 bp. The16S rRNA gene sequences of the four strains showed a mean similarity of 99.3 % with the most closely related, recognized species, Rhizobium vitis. The corresponding recA and glnA gene sequences showed similarities with established species of Rhizobium of less than 86.5 % and less than 89.6 %, respectively. These low similarities indicated that the four strains represented a novel species of the genus Rhizobium. The strains were also found to be distinguishable from the closest related, established species (R. vitis) by rep-PCR DNA fingerprinting, analysis of cellular fatty acid profiles and from the results of a series of phenotypic tests. The level of DNA-DNA relatedness between the representative strain CCNWSX 0483(T) and Rhizobium vitis IAM 14140(T) was only 40.13 %. Therefore, a novel species, Rhizobium taibaishanense sp. nov., is proposed, with strain CCNWSX 0483(T) ( = ACCC 14971(T) = HAMBI 3214(T)) as the type strain. In nodulation and pathogenicity tests, none of the four strains of Rhizobium taibaishanense sp. nov. was able to induce any nodule or tumour formation on plants. As no amplicons were detected when DNA from the strains was run in PCR with primers for the detection of nodA, nifH and virC gene sequences, the strains probably do not carry sym or vir genes.

  16. Bradyrhizobium subterraneum sp. nov., a symbiotic nitrogen-fixing bacterium from root nodules of groundnuts.

    Science.gov (United States)

    Grönemeyer, Jann Lasse; Chimwamurombe, Percy; Reinhold-Hurek, Barbara

    2015-10-01

    Seven strains of symbiotic bacteria from root nodules of local races of Bambara groundnut (Vigna subterranea) and peanuts (Arachis hypogaea) grown on subsistence farmers' fields in the Kavango region, Namibia, were previously characterized and identified as a novel group within the genus Bradyrhizobium. To corroborate their taxonomic status, these strains were further characterized using a polyphasic approach. All strains possessed identical 16S rRNA gene sequences with Bradyrhizobium yuanmingense CCBAU 10071T being the most closely related type strain in the 16S rRNA gene phylogenetic analysis, and Bradyrhizobium daqingense CCBAU 15774T in the ITS sequence analysis. Phylogenetic analysis of concatenated glnII-recA-rpoB-dnaK placed the strains in a highly supported lineage distinct from named species of the genus Bradyrhizobium, most closely related to Bradyrhizobium yuanmingense CCBAU 10071T. The species status was validated by results of DNA–DNA hybridization. Phylogenetic analysis of nifH genes placed the novel strains in a group with nifH of ‘Bradyrhizobium arachidis’ CCBAU 051107 that also nodulates peanuts. The combination of phenotypic characteristics from several tests including carbon source utilization and antibiotic resistance could be used to differentiate representative strains from recognized species of the genus Bradyrhizobium. Novel strain 58 2-1T induced effective nodules on V. subterranea, Vigna unguiculata and A. hypogaea, and some strains on Lablab purpureus. Based on the data presented, we conclude that our strains represent a novel species for which the name Bradyrhizobium subterraneum sp. nov. is proposed, with 58 2-1T [ = DSM 100298T = LMG 28792T = NTCCM0016T (Windhoek)] as the type strain. The DNA G+C content of strain 58 2-1T was 64.7 mol% (T m).

  17. Sinorhizobium fredii USDA257 Translocates NopP into Vigna unguiculata Root Nodules

    Science.gov (United States)

    Type III secretion systems (T3SSs), which are found in many Gram-negative bacterial pathogens, inject virulence proteins directly into host cells during infection. T3SSs are also present in some strains of rhizobia, bacteria that form symbiotic associations with legumes and fix nitrogen in speciali...

  18. Rhizobium acidisoli sp. nov., isolated from root nodules of Phaseolus vulgaris in acid soils.

    Science.gov (United States)

    Román-Ponce, Brenda; Jing Zhang, Yu; Soledad Vásquez-Murrieta, María; Hua Sui, Xin; Feng Chen, Wen; Carlos Alberto Padilla, Juan; Wu Guo, Xian; Lian Gao, Jun; Yan, Jun; Hong Wei, Ge; Tao Wang, En

    2016-01-01

    Two Gram-negative, aerobic, non-motile, rod-shaped bacterial strains, FH13T and FH23, representing a novel group of Rhizobium isolated from root nodules of Phaseolus vulgaris in Mexico, were studied by a polyphasic analysis. Phylogeny of 16S rRNA gene sequences revealed them to be members of the genus Rhizobium related most closely to 'Rhizobium anhuiense' CCBAU 23252 (99.7 % similarity), Rhizobium leguminosarum USDA 2370T (98.6 %), and Rhizobium sophorae CCBAU 03386T and others ( ≤ 98.3 %). In sequence analyses of the housekeeping genes recA, glnII and atpD, both strains formed a subclade distinct from all defined species of the genus Rhizobium at sequence similarities of 82.3-94.0 %, demonstrating that they represented a novel genomic species in the genus Rhizobium. Mean levels of DNA-DNA relatedness between the reference strain FH13T and the type strains of related species varied between 13.0 ± 2.0 and 52.1 ± 1.2 %. The DNA G+C content of strain FH13T was 63.5 mol% (Tm). The major cellular fatty acids were 16 : 0, 17 : 0 anteiso, 18 : 0, summed feature 2 (12 : 0 aldehyde/unknown 10.928) and summed feature 8 (18 : 1ω7c). The fatty acid 17 : 1ω5c was unique for this strain. Some phenotypic features, such as failure to utilize adonitol, l-arabinose, d-fructose and d-fucose, and ability to utilize d-galacturonic acid and itaconic acid as carbon source, could also be used to distinguish strain FH13T from the type strains of related species. Based upon these results, a novel species, Rhizobium acidisoli sp. nov., is proposed, with FH13T ( = CCBAU 101094T = HAMBI 3626T = LMG 28672T) as the type strain.

  19. The strigolactone biosynthesis gene DWARF27 is co-opted in rhizobium symbiosis.

    Science.gov (United States)

    van Zeijl, Arjan; Liu, Wei; Xiao, Ting Ting; Kohlen, Wouter; Yang, Wei-Cai; Bisseling, Ton; Geurts, René

    2015-10-26

    Strigolactones are a class of plant hormones whose biosynthesis is activated in response to phosphate starvation. This involves several enzymes, including the carotenoid cleavage dioxygenases 7 (CCD7) and CCD8 and the carotenoid isomerase DWARF27 (D27). D27 expression is known to be responsive to phosphate starvation. In Medicago truncatula and rice (Oryza sativa) this transcriptional response requires the GRAS-type proteins NSP1 and NSP2; both proteins are essential for rhizobium induced root nodule formation in legumes. In line with this, we questioned whether MtNSP1-MtNSP2 dependent MtD27 regulation is co-opted in rhizobium symbiosis. We provide evidence that MtD27 is involved in strigolactone biosynthesis in M. truncatula roots upon phosphate stress. Spatiotemporal expression studies revealed that this gene is also highly expressed in nodule primordia and subsequently becomes restricted to the meristem and distal infection zone of a mature nodules. A similar expression pattern was found for MtCCD7 and MtCCD8. Rhizobium lipo-chitooligosaccharide (LCO) application experiments revealed that of these genes MtD27 is most responsive in an MtNSP1 and MtNSP2 dependent manner. Symbiotic expression of MtD27 requires components of the symbiosis signaling pathway; including MtDMI1, MtDMI2, MtDMI3/MtCCaMK and in part MtERN1. This in contrast to MtD27 expression upon phosphate starvation, which only requires MtNSP1 and MtNSP2. Our data show that the phosphate-starvation responsive strigolactone biosynthesis gene MtD27 is also rapidly induced by rhizobium LCO signals in an MtNSP1 and MtNSP2-dependent manner. Additionally, we show that MtD27 is co-expressed with MtCCD7 and MtCCD8 in nodule primordia and in the infection zone of mature nodules.

  20. Role of mungbean root nodule associated fluorescent Pseudomonas and rhizobia in suppressing the root rotting fungi and root knot nematodes in chickpea (Cicer arietinum L.)

    International Nuclear Information System (INIS)

    Noreen, R.; Shafique, A.; Haque, S.E.; Ali, S.A.

    2016-01-01

    Three isolates each of fluorescent Pseudomonas (NAFP-19, NAFP-31 and NAFP-32) and rhizobia (NFB- 103, NFB-107 and NFB-109) which were originally isolated from root nodules of mungbean (Vigna radiata) showed significant biocontrol activity in the screen house and under field condition, against root rotting fungi viz., Macrophomina phaseolina, Fusarium solani, F. oxysporum and Rhizoctonia solani evaluated on chickpea. Biocontrol potential of these isolates was also evaluated against Meloidogyne incognita, the root knot nematode. Application of Pseudomonas and rhizobial isolates as a soil drench, separately or mixed significantly reduced root rot disease under screen house and field conditions. Nematode penetration in roots was also found significantly less in rhizobia or Pseudomonas treatments used separately or mixed as compared to control. Fluorescent Pseudomonas treated plants produced greater number of nodules per plant than control plants and about equal to rhizobia treated plants, indicating that root nodule associated fluorescent Pseudomonas enhance root nodulation. (author)

  1. Induced systemic resistance against Botrytis cinerea by Micromonospora strains isolated from root nodules

    Directory of Open Access Journals (Sweden)

    Pilar eMartínez-Hidalgo

    2015-09-01

    Full Text Available Micromonospora is a Gram positive bacterium that can be isolated from nitrogen fixing nodules from healthy leguminous plants, where they could be beneficial to the plant. Their plant growth promoting activity in legume and non-legume plants has been previously demonstrated. The present study explores the ability of Micromonospora strains to control fungal pathogens and to stimulate plant immunity. Micromonospora strains isolated from surface sterilized nodules of alfalfa showed in vitro antifungal activity against several pathogenic fungi. Moreover, root inoculation of tomato plants with these Micromonospora strains effectively reduced leaf infection by the fungal pathogen Botrytis cinerea, despite spatial separation between both microorganisms. This induced systemic resistance, confirmed in different tomato cultivars, is long lasting. Gene expression analyses evidenced that Micromonospora stimulates the plant capacity to activate defense mechanisms upon pathogen attack. The defensive response of tomato plants inoculated with Micromonospora spp. differs from that of non-inoculated plants, showing a stronger induction of jasmonate-regulated defenses when the plant is challenged with a pathogen. The hypothesis of jasmonates playing a key role in this defense priming effect was confirmed using defense-impaired tomato mutants, since the JA-deficient line def1 was unable to display a long term induced resistance upon Micromonospora spp. inoculation.In conclusion, nodule isolated Micromonospora strains should be considered excellent candidates as biocontrol agents as they combine both direct antifungal activity against plant pathogens and the ability to prime plant immunity.

  2. Identification of a transport mechanism for NH4+ in the symbiosome membrane of pea root nodules

    DEFF Research Database (Denmark)

    Mouritzen, P.; Rosendahl, L.

    1997-01-01

    Symbiosome membrane vesicles, facing bacteroid-side-out, were purified from pea (Pisum sativum L.) root nodules and used to study NH4+ transport across the membrane by recording vesicle uptake of the NH4+ analog [C-14]methylamine (MA). Membrane potentials (Delta psi) were imposed on the vesicles ...

  3. Complete Genome Sequence of Micromonospora Strain L5, a Potential Plant-Growth-Regulating Actinomycete, Originally Isolated from Casuarina equisetifolia Root Nodules

    Energy Technology Data Exchange (ETDEWEB)

    Hirsch, A. M.; Alvarado, J.; Bruce, D.; Chertkov, O.; De Hoff, P. L.; Detter, J. C.; Fujishige, N. A.; Goodwin, L. A.; Han, J.; Han, S.; Ivanova, N.; Land, M. L.; Lum, M. R.; Milani-Nejad, N.; Nolan, M.; Pati, A.; Pitluck, S.; Tran, S. S.; Woyke, T.; Valdes, M.

    2013-08-29

    Micromonospora species live in diverse environments and exhibit a broad range of functions including antibiotic production, biocontrol, and ability to degrade complex polysaccharides. To learn more about these versatile actinomycetes, we sequenced the genome of strain L5, originally isolated from root nodules of an actinorhizal plant growing in Mexico.

  4. Metabolic responses in root nodules of Phaseolus vulgaris and Vicia sativa exposed to the imazamox herbicide.

    Science.gov (United States)

    García-Garijo, A; Tejera, N A; Lluch, C; Palma, F

    2014-05-01

    Alterations on growth, amino acids metabolism and some antioxidant enzyme activities as result of imazamox treatment were examined in determinate and indeterminate nodules, formed by Phaseolus vulgaris and Vicia sativa, respectively. Young seedlings of both legumes were inoculated with their respective microsymbionts and grown under controlled conditions. At vegetative growth, plants were treated with imazamox (250μM) in the nutrient solution and harvested 7days after. Imazamox was mainly accumulated in V. sativa where concentrations were more than six fold higher than those detected in P. vulgaris. Nodule dry weight and total nitrogen content were reduced by the herbicide treatment: the highest decrease of nodule biomass (50%) and nitrogen content (40%) were registered in V. sativa and P. vulgaris, respectively. The concentration of branched-chain amino acids (BCAA) did not change in neither determinate nor indeterminate nodules even though the acetohydroxyacid synthase activity decreased in root and nodules of both symbioses with the herbicide application. Based on this last result and taking into account that total free amino acids increased in roots but not in nodules of common vetch, a possible BCAA translocation from root to nodule could occur. Our results suggest that the maintenance of BCAA balance in nodule become a priority for the plant in such conditions. The involvement of activities glutathione-S-transferase, guaiacol peroxidase and superoxide dismutase in the response of the symbioses to imazamox are also discussed. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Agrobacterium salinitolerans sp. nov., a saline-alkaline-tolerant bacterium isolated from root nodule of Sesbania cannabina.

    Science.gov (United States)

    Yan, Jun; Li, Yan; Yan, Hui; Chen, Wen Feng; Zhang, Xiaoxia; Wang, En Tao; Han, Xiao Zeng; Xie, Zhi Hong

    2017-06-01

    Two Gram-staining-negative, aerobic bacteria (YIC 5082T and YIC4104) isolated from root nodules of Sesbania cannabina grown in a high-salt and alkaline environment were identified as a group in the genus Agrobacterium because they shared 100 and 99.7 % sequence similarities of 16S rRNA and recA+atpD genes, respectively. These two strains showed 99.2/100 % and 93.9/95.4 % 16S rRNA and recA+atpD gene sequence similarities to Agrobacterium radiobacter LMG140T and Agrobacterium. pusense NRCPB10T, respectively. The average nucleotide identities (ANI) of genome sequences were 89.95 % or lower between YIC 5082T and the species of the genus Agrobacterium examined. Moreover, these two test strains formed a unique nifH lineage deeply separated from other rhizobia. Although the nodC gene was not detected in YIC 5082T and YIC4104, they could form effective root nodules on S. cannabina plants. The main cellular fatty acids in YIC 5082T were summed feature 8 (C18 : 1ω7c/C18 : 1ω6c), C19 : 0cyclo ω8c, summed feature 2 (C12 : 0 aldehyde/unknown equivalent chain length 10.9525) and C16 : 0. The DNA G+C content of YIC 5082T was 59.3 mol%. The failure to utilize d-sorbitol as a carbon source distinguished YIC 5082T from the type strains of related species. YIC 5082T could grow in presence of 5.0 % (w/v) NaCl and at a pH of up to 10.0. Based on results regarding the genetic and phenotypic properties of YIC 5082T and YIC4104 the name Agrobacterium salinitolerans sp. nov. is proposed and YIC 5082T (=HAMBI 3646T=LMG 29287T) is designed as the type strain.

  6. Two Lotus japonicus symbiosis mutants impaired at distinct steps of arbuscule development.

    Science.gov (United States)

    Groth, Martin; Kosuta, Sonja; Gutjahr, Caroline; Haage, Kristina; Hardel, Simone Liesel; Schaub, Miriam; Brachmann, Andreas; Sato, Shusei; Tabata, Satoshi; Findlay, Kim; Wang, Trevor L; Parniske, Martin

    2013-07-01

    Arbuscular mycorrhiza (AM) fungi form nutrient-acquiring symbioses with the majority of higher plants. Nutrient exchange occurs via arbuscules, highly branched hyphal structures that are formed within root cortical cells. With a view to identifying host genes involved in AM development, we isolated Lotus japonicus AM-defective mutants via a microscopic screen of an ethyl methanesulfonate-mutagenized population. A standardized mapping procedure was developed that facilitated positioning of the defective loci on the genetic map of L. japonicus, and, in five cases, allowed identification of mutants of known symbiotic genes. Two additional mutants representing independent loci did not form mature arbuscules during symbiosis with two divergent AM fungal species, but exhibited signs of premature arbuscule arrest or senescence. Marker gene expression patterns indicated that the two mutants are affected in distinct steps of arbuscule development. Both mutants formed wild-type-like root nodules upon inoculation with Mesorhizobium loti, indicating that the mutated loci are essential during AM but not during root nodule symbiosis. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  7. Rhizobium hedysari sp. nov., a novel species isolated from a root nodule of Hedysarum multijugum in China.

    Science.gov (United States)

    Xu, Lin; Shi, Jianfeng; Li, Caixia; Zhu, Shengan; Li, Bo

    2017-04-01

    A strain 5-1-2 T was isolated from a root nodule of Hedysarum multijugum collected from Zhangye city, Gansu province, north-west China. Phylogenetic analysis based on the 16S rRNA gene sequence and other housekeeping genes (recA and atpD) indicated that the strain represents a novel species in the genus Rhizobium close to the strain Rhizobium subbaraonis JC85 T with similarities of 98.27, 88.92 and 89.62%, respectively. Strain 5-1-2 T contained Q-10 as the predominant ubiquinone. Our results showed that the major fatty acids were feature 8 (C 18:1 ω7c and/or C 18:1 ω6c; 38.90%). In addition, the DNA-DNA hybridizations with the type strains R. subbaraonis JC85 T and Rhizobium halophytocola YC6881 T were 39.2 ± 2.1 and 44.3 ± 1.9, respectively. Therefore, a novel species Rhizobium hedysari sp. nov. is proposed, and 5-1-2 T (=CGMCC1.15677 T  = NBRC112532 T) is designated as the type strain.

  8. Rhizobium qilianshanense sp. nov., a novel species isolated from root nodule of Oxytropis ochrocephala Bunge in China.

    Science.gov (United States)

    Xu, Lin; Zhang, Yong; Deng, Zheng Shan; Zhao, Liang; Wei, Xiu Li; Wei, Ge Hong

    2013-03-01

    During a study of the diversity and phylogeny of rhizobia isolated from root nodules of Oxytropis ochrocephala grown in the northwest of China, four strains were classified in the genus Rhizobium on the basis of their 16S rRNA gene sequences. These strains have identical 16S rRNA gene sequences, which showed a mean similarity of 94.4 % with the most closely related species, Rhizobium oryzae. Analysis of recA and glnA sequences showed that these strains have less than 88.1 and 88.7 % similarity with the defined species of Rhizobium, respectively. The genetic diversity revealed by ERIC-PCR fingerprinting indicated that the isolates correspond to different strains. Strain CCNWQLS01(T) contains Q-10 as the predominant ubiquinone. The major fatty acids were identified as feature 8 (C18: 1ω7c and/or C18: 1ω6c; 67.2 %). Therefore, a novel species Rhizobium qilianshanense sp. nov. is proposed, and CCNWQLS01(T) (= ACCC 05747(T) = JCM 18337(T)) is designated as the type strain.

  9. Novel Rhizobium lineages isolated from root nodules of the common bean (Phaseolus vulgaris L.) in Andean and Mesoamerican areas.

    Science.gov (United States)

    Ribeiro, Renan Augusto; Ormeño-Orrillo, Ernesto; Dall'Agnol, Rebeca Fuzinatto; Graham, Peter H; Martinez-Romero, Esperanza; Hungria, Mariangela

    2013-09-01

    The taxonomic affiliations of nineteen root-nodule bacteria isolated from the common bean (Phaseolus vulgaris L.) in Mexico, Ecuador and Brazil were investigated by analyses of 16S rRNA and of four protein-coding housekeeping genes. One strain from Mexico could be assigned to Rhizobium etli and two from Brazil to Rhizobium leucaenae, whereas another from Mexico corresponded to a recently described bean-nodulating species-level lineage related to R. etli and Rhizobium phaseoli. Ten strains isolated in Ecuador and Mexico corresponded to three novel Rhizobium lineages that fall into the R. phaseoli/R. etli/Rhizobium leguminosarum clade. One of those lineages, with representatives isolated mostly from Ecuador, seems to be dominant in beans from that Andean region. Only one of the Mexican strains clustered within the Rhizobium tropici clade, but as an independent lineage. Interestingly, four strains were affiliated with species within the Rhizobium radiobacter clade. The existence of yet non-described native Rhizobium lineages in both the Andean and Mesoamerican areas is discussed in relation to common-bean diversity and environmental conditions. Copyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  10. Stress tolerance, genetic analysis and symbiotic properties of root-nodulating bacteria isolated from Mediterranean leguminous shrubs in Central Spain.

    Science.gov (United States)

    Ruiz-Díez, Beatriz; Fajardo, Susana; Puertas-Mejía, Miguel Angel; de Felipe, María del Rosario; Fernández-Pascual, Mercedes

    2009-01-01

    Nine root-nodulating bacterial isolates were obtained from the leguminous shrubs Spartium junceum, Adenocarpus hispanicus, Cytisus purgans, Cytisus laburnuum, Retama sphaerocarpa and Colutea arborescens in areas of Central Spain. A poliphasic approach analyzing phenotypic, symbiotic and genetic properties was used to study their diversity and characterize them in relation to Mediterranean conditions. Stress tolerance assays revealed marked variations in salinity, extreme pH and cadmium tolerance compared with reference strains, with the majority showing salinity, alkalinity and Cd tolerance and three of them growing at acid pH. Variation within the 16S rRNA gene was examined by amplified 16S rDNA restriction analysis (ARDRA) and direct sequencing to show genetic diversity. Phylogeny confirmed the close relationship of four isolates with Bradyrhizobium canariense, three with Phylobacterium myrsinacearum, one with Rhizobium rhizogenes and another with Mesorhizobium huakuii. The cross inoculation tests revealed wide spectra of nodulation. This is the first report of P. myrsinacearum being able to nodulate these leguminous shrubs, and also the first time reported the association between B.canariense, R. rhizogenes and M. huakuii and C. laburnuum, C. purgans and C. arborescens, respectively. These results suggested that native rhizobia could be suitable candidates as biofertilizers and/or inoculants of leguminous shrubs with restoration or revegetation purposes in Mediterranean areas.

  11. Poly-β-hydroxybutyrate and exopolysaccharide biosynthesis by bacterial isolates from pigeonpea [Cajanus cajan (L.) Millsp] root nodules.

    Science.gov (United States)

    Fernandes, Paulo Ivan; de Oliveira, Paulo Jansen; Rumjanek, Norma Gouvêa; Xavier, Gustavo Ribeiro

    2011-02-01

    The bacterial strains that are able to produce biopolymers that are applied in industrial sectors present a source of renewable resources. Some microorganisms are already applied at several industrial sectors, but the prospecting of new microbes must bring microorganisms that are feasible to produce interesting biopolymers more efficiently and in cheaper conditions. Among the biopolymers applied industrially, polyhydroxybutyrate (PHB) and exopolysaccharides (EPS) stand out because of its applications, mainly in biodegradable plastic production and in food industry, respectively. In this context, the capacity of bacteria isolated from pigeonpea root nodules to produce EPS and PHB was evaluated, as well as the cultural characterization of these isolates. Among the 38 isolates evaluated, the majority presented fast growth and ability to acidify the culture media. Regarding the biopolymer production, five isolates produced more than 10 mg PHB per liter of culture medium. Six EPS producing bacteria achieved more than 200 mg EPS per liter of culture medium. Evaluating different carbon sources, the PHB productivity of the isolate 24.6b reached 69% of cell dry weight when cultured with starch as sole carbon source, and the isolate 8.1c synthesized 53% PHB in dry cell biomass and more than 1.3 g L⁻¹ of EPS when grown using xylose as sole carbon source.

  12. Paenibacillus medicaginis sp. nov. a chitinolytic endophyte isolated from the root nodule of alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Lai, Wei-An; Hameed, Asif; Lin, Shih-Yao; Hung, Mei-Hua; Hsu, Yi-Han; Liu, You-Cheng; Shahina, Mariyan; Shen, Fo-Ting; Young, Chiu-Chung

    2015-08-04

    A Gram-stain-variable, short-rod-shaped, endospore-forming, strictly aerobic, non-motile, chitinolytic and endophytic bacterium, designated strain CC-Alfalfa-19T, exhibiting unusual bipolar appendages was isolated from the root nodule of alfalfa (Medicago sativa L.) in Taiwan and subjected to a polyphasic taxonomy. Based on 16S rRNA gene sequence analysis, strain CC-Alfalfa-19T was found to be most closely related to Paenibacillus puldeungensis CAU 9324T (95.2 %), whereas other Paenibacillus species shared ≤95.0 % sequence similarity. The phylogenetic analysis revealed a distinct phyletic lineage established by strain CC-Alfalfa-19T with respect to other Paenibacillus species. Fatty acids comprised predominantly anteiso-C15:0, C16:0, anteiso-C17:0 and iso-C16. Menaquinone 7 (MK-7) was identified as the sole respiratory quinone and the genomic DNA G+C content was 42.7 mol%. Polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, an unidentified glycolipid and an unidentified lipid. The diagnostic diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. Based on the polyphasic taxonomic evidences that were in line with the genus Paenibacillus and additional distinguishing characteristics, strain CC-Alfalfa-19T is considered to represent a novel species, for which the name Paenibacillus medicaginis sp. nov. (type strain CC-Alfalfa-19T = BCRC 80441T = JCM 18446T) is proposed.

  13. The monomeric GTPase RabA2 is required for progression and maintenance of membrane integrity of infection threads during root nodule symbiosis.

    Science.gov (United States)

    Dalla Via, Virginia; Traubenik, Soledad; Rivero, Claudio; Aguilar, O Mario; Zanetti, María Eugenia; Blanco, Flavio Antonio

    2017-04-01

    Progression of the infection canal that conducts rhizobia to the nodule primordium requires a functional Rab GTPase located in Golgi/trans-Golgi that also participate in root hair polar growth. Common bean (Phaseolus vulgaris) symbiotically associates with its partner Rhizobium etli, resulting in the formation of root nitrogen-fixing nodules. Compatible bacteria can reach cortical cells in a tightly regulated infection process, in which the specific recognition of signal molecules is a key step to select the symbiotic partner. In this work, we show that RabA2, a monomeric GTPase from common bean, is required for the progression of the infection canal, referred to as the infection thread (IT), toward the cortical cells. Expression of miss-regulated mutant variants of RabA2 resulted in an increased number of abortive infection events, including bursting of ITs and a reduction in the number of nodules. Nodules formed in these plants were small and contained infected cells with disrupted symbiosome membranes, indicating either early senescence of these cells or defects in the formation of the symbiosome membrane during bacterial release. RabA2 localized to mobile vesicles around the IT, but mutations that affect GTP hydrolysis or GTP/GDP exchange modified this localization. Colocalization of RabA2 with ArfA1 and a Golgi marker indicates that RabA2 localizes in Golgi stacks and the trans-Golgi network. Our results suggest that RabA2 is part of the vesicle transport events required to maintain the integrity of the membrane during IT progression.

  14. Rhizobium-legume symbioses: the crucial role of plant immunity.

    Science.gov (United States)

    Gourion, Benjamin; Berrabah, Fathi; Ratet, Pascal; Stacey, Gary

    2015-03-01

    New research results have significantly revised our understanding of the rhizobium-legume infection process. For example, Nod factors (NFs), previously thought to be absolutely essential for this symbiosis, were shown to be dispensable under particular conditions. Similarly, an NF receptor, previously considered to be solely involved in symbiosis, was shown to function during plant pathogen infections. Indeed, there is a growing realization that plant innate immunity is a crucial component in the establishment and maintenance of symbiosis. We review here the factors involved in the suppression of plant immunity during rhizobium-legume symbiosis, and we attempt to place this information into context with the most recent and sometimes surprising research results. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Paenibacillus medicaginis sp. nov. a chitinolytic endophyte isolated from a root nodule of alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Lai, Wei-An; Hameed, Asif; Lin, Shih-Yao; Hung, Mei-Hua; Hsu, Yi-Han; Liu, You-Cheng; Shahina, Mariyan; Shen, Fo-Ting; Young, Chiu-Chung

    2015-11-01

    A Gram-stain-variable, short-rod-shaped, endospore-forming, strictly aerobic, non-motile, chitinolytic and endophytic bacterium, designated strain CC-Alfalfa-19T, exhibiting unusual bipolar appendages was isolated from a root nodule of alfalfa (Medicago sativa L.) in Taiwan and subjected to a polyphasic taxonomic study. Based on 16S rRNA gene sequence analysis, strain CC-Alfalfa-19T was found to be most closely related to Paenibacillus puldeungensis CAU 9324T (95.2 %), whereas other species of the genus Paenibacillus shared ≤ 95.0 % sequence similarity. The phylogenetic analysis revealed a distinct phyletic lineage established by strain CC-Alfalfa-19T with respect to other species of the genus Paenibacillus. Fatty acids comprised predominantly anteiso-C15 : 0, C16 : 0, anteiso-C17 : 0 and iso-C16 : 0. Menaquinone 7 (MK-7) was identified as the sole respiratory quinone and the genomic DNA G+C content was 42.7 mol%. Polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, an unidentified glycolipid and an unidentified lipid. The diagnostic diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. Based on the polyphasic taxonomic evidence that was in line with the genus Paenibacillus and additional distinguishing characteristics, strain CC-Alfalfa-19T is considered to represent a novel species, for which the name Paenibacillus medicaginis sp. nov. (type strain CC-Alfalfa-19T = BCRC 80441T = JCM 18446T) is proposed.

  16. CO2 fixation in alfalfa and birdsfoot trefoil root nodules and partitioning of 14C to the plant

    International Nuclear Information System (INIS)

    Maxwell, C.A.; Vance, C.P.; Heichel, G.H.; Stade, S.

    1984-01-01

    The objectives of this study were to determine if nonphotosynthetic CO 2 fixation by root nodules contributes carbon for the assimilation of fixed N 2 in alfalfa (Medicago sativa L.) and birdsfoot trefoil (Lotus corniculatus L.) and if assimilation products are partitioned to different plant organs. Effective alfalfa nodules excised from or attached to roots had apparent 14 CO 2 fixation rates of 50 to 80 μg CO 2 kg -1 s -1 (dry weight) at 0.0012 to 0.0038 mole fraction CO 2 . Nodule CO 2 fixation rates increased six- to seven-fold as ambient CO 2 was raised from 0.0038 to 0.0663 mole fraction. Respiration rates of nodules (3 to 4 mg CO 2 kg -1 s -1 ) were 10 to 100-fold higher than 14 CO 2 fixation rates of nodules. Pulse chase experiments with 14 CO 2 combined with nodule and xylem sap analysis demonstrated the initial products of root and nodule CO 2 fixation were organic acids. However, the export of fixed 14 C from effective nodules was primarily in the form of amino acids. In contrast, nodule and/or root fixed 14 C in ineffectively nodulated alfalfa and denodulated effective alfalfa and birdsfoot trefoil was transported primarily as organic acids. Aspartate, asparagine, alanine, glutamate, and glutamine were the most heavily labeled compounds in the amino acid fraction of both effective alfalfa and birdsfoot trefoil nodules exposed to 14 CO 2 . By contrast, asparate, asparagine, and glutamine were the predominantly labeled amino acids in xylem sap collected from nodulated effective roots exposed to 14 CO 2 . The occurrence of nodule CO 2 fixation in alfalfa and birdsfoot trefoil and the export of fixed carbon as asparagine and aspartate to roots and shoots is consistent with a role for CO 2 fixation by nodules in providing carbon skeletons for assimilation and transport of symbiotically fixed N 2

  17. Bradyrhizobium namibiense sp. nov., a symbiotic nitrogen-fixing bacterium from root nodules of Lablab purpureus, hyacinth bean, in Namibia.

    Science.gov (United States)

    Grönemeyer, Jann Lasse; Bünger, Wiebke; Reinhold-Hurek, Barbara

    2017-10-16

    Four strains of symbiotic bacteria from root nodules of hyacinth bean (Lablab purpureus (L.) Sweet) from Namibia were previously identified as a novel group within the genus Bradyrhizobium. To confirm their taxonomic status, these strains were further characterized by taking a polyphasic approach. The type strain possessed 16S rRNA gene sequences identical to Bradyrhizobium paxllaeri LMTR 21 T and Bradyrhizobiumicense LMTR 13 T , the full-length sequences were identical to those retrieved from SAMN05230119 and SAMN05230120, respectively. However, the intergenic spacer sequences of the novel group showed identities of less than 93.1 % to described Bradyrhizobium species and were placed in a well-supported separate lineage in the phylogenetic tree. Phylogenetic analyses of six concatenated housekeeping genes, recA, glnII, gyrB, dnaK, atpD and rpoB, corroborated that the novel strains belonged to a lineage distinct from named species of the genus Bradyrhizobium, with highest sequence identities to Bradyrhizobiumjicamae and B. paxllaeri (below 93 %). The species status was validated by results of DNA-DNA hybridization and average nucleotide identity values of genome sequences. The combination of phenotypic characteristics from several tests, including carbon source utilization and antibiotic resistance, could be used to differentiate representative strains from recognized species of the genus Bradyrhizobium. Phylogenetic analysis of nodC and nifH genes placed the novel strains in a group with B. paxllaeri and B.lablabi. Novel strain 5-10 T induces effective nodules on Lablab purpureus, Vigna subterranea, Vigna unguiculata and Arachis hypogaea. Based on our results, we conclude that our strains represent a novel species for which the name Bradyrhizobium namibiense sp. nov. is proposed, with type strain 5-10 T [LMG 28789, DSM 100300, NTCCM0017 (Windhoek)].

  18. Bradyrhizobium kavangense sp. nov., a symbiotic nitrogen-fixing bacterium from root nodules of traditional Namibian pulses.

    Science.gov (United States)

    Lasse Grönemeyer, Jann; Hurek, T; Reinhold-Hurek, Barbara

    2015-12-01

    Eight strains of symbiotic bacteria from root nodules of local races of cowpea (Vigna unguiculata) and Bambara groundnut (Vigna subterranea) grown on subsistence farmers' fields in the Kavango region, Namibia, were previously characterized and identified as a novel group within the genus Bradyrhizobium. To clarify their taxonomic status, these strains were further characterized using a polyphasic approach. In phylogenetic analysis of the 16S rRNA gene sequence the novel group was most closely related to Bradyrhizobium iriomotense EK05T and Bradyrhizobium ingae BR 10250T, and to 'Bradyrhizobium arachidis' CCBAU 051107 in the ITS sequence analysis. Phylogenetic analysis of concatenated glnII-recA-rpoB-dnaK sequences placed the strains in a lineage distinct from named species of the genus Bradyrhizobium. The species status was validated by results of DNA-DNA hybridization. Phylogenetic analysis of nifH and nodC genes placed the novel strains in a group with 'B. arachidis' CCBAU 051107. The combination of phenotypic characteristics from several tests including carbon source utilization and antibiotic resistance could be used to differentiate representative strains from recognized species of the genus Bradyrhizobium. Novel strain 14-3T induces effective nodules on Vigna subterranea, Vigna unguiculata, Arachis hypogaea and Lablab purpureus. Based on the data presented, it is concluded that the strains represent a novel species of the genus Bradyrhizobium, for which the name Bradyrhizobium kavangense sp. nov. is proposed. The type strain is 14-3T [ = DSM 100299T = LMG 28790T = NTCCM 0012T (Windhoek)]. The DNA G+C content of strain 14-3T is 63.8 mol% (Tm).

  19. Legume bioactive compounds: influence of rhizobial inoculation

    Directory of Open Access Journals (Sweden)

    Luis R. Silva

    2017-04-01

    Full Text Available Legumes consumption has been recognized as beneficial for human health, due to their content in proteins, fiber, minerals and vitamins, and their cultivation as beneficial for sustainable agriculture due to their ability to fix atmospheric nitrogen in symbiosis with soil bacteria known as rhizobia. The inoculation with these baceria induces metabolic changes in the plant, from which the more studied to date are the increases in the nitrogen and protein contents, and has been exploited in agriculture to improve the crop yield of several legumes. Nevertheless, legumes also contain several bioactive compounds such as polysaccharides, bioactive peptides, isoflavones and other phenolic compounds, carotenoids, tocopherols and fatty acids, which makes them functional foods included into the nutraceutical products. Therefore, the study of the effect of the rhizobial inoculation in the legume bioactive compounds content is gaining interest in the last decade. Several works reported that the inoculation of different genera and species of rhizobia in several grain legumes, such as soybean, cowpea, chickpea, faba bean or peanut, produced increases in the antioxidant potential and in the content of some bioactive compounds, such as phenolics, flavonoids, organic acids, proteins and fatty acids. Therefore, the rhizobial inoculation is a good tool to enhance the yield and quality of legumes and further studies on this field will allow us to have plant probiotic bacteria that promote the plant growth of legumes improving their functionality.

  20. Benefits from Below: Silicon Supplementation Maintains Legume Productivity under Predicted Climate Change Scenarios.

    Science.gov (United States)

    Johnson, Scott N; Ryalls, James M W; Gherlenda, Andrew N; Frew, Adam; Hartley, Susan E

    2018-01-01

    Many studies demonstrate that elevated atmospheric carbon dioxide concentrations (eCO 2 ) can promote root nodulation and biological nitrogen fixation (BNF) in legumes such as lucerne ( Medicago sativa ). But when elevated temperature (eT) conditions are applied in tandem with eCO 2 , a more realistic scenario for future climate change, the positive effects of eCO 2 on nodulation and BNF in M. sativa are often much reduced. Silicon (Si) supplementation of M. sativa has also been reported to promote root nodulation and BNF, so could potentially restore the positive effects of eCO 2 under eT. Increased nitrogen availability, however, could also increase host suitability for aphid pests, potentially negating any benefit. We applied eCO 2 (+240 ppm) and eT (+4°C), separately and in combination, to M. sativa growing in Si supplemented (Si+) and un-supplemented soil (Si-) to determine whether Si moderated the effects of eCO 2 and eT. Plants were either inoculated with the aphid Acyrthosiphon pisum or insect-free. In Si- soils, eCO 2 stimulated plant growth by 67% and nodulation by 42%, respectively, whereas eT reduced these parameters by 26 and 48%, respectively. Aphids broadly mirrored these effects on Si- plants, increasing colonization rates under eCO 2 and performing much worse (reduced abundance and colonization) under eT when compared to ambient conditions, confirming our hypothesized link between root nodulation, plant growth, and pest performance. Examined across all CO 2 and temperature regimes, Si supplementation promoted plant growth (+93%), and root nodulation (+50%). A. pisum abundance declined sharply under eT conditions and was largely unaffected by Si supplementation. In conclusion, supplementing M. sativa with Si had consistent positive effects on plant growth and nodulation under different CO 2 and temperature scenarios. These findings offer potential for using Si supplementation to maintain legume productivity under predicted climate change scenarios

  1. Benefits from Below: Silicon Supplementation Maintains Legume Productivity under Predicted Climate Change Scenarios

    Directory of Open Access Journals (Sweden)

    Scott N. Johnson

    2018-02-01

    Full Text Available Many studies demonstrate that elevated atmospheric carbon dioxide concentrations (eCO2 can promote root nodulation and biological nitrogen fixation (BNF in legumes such as lucerne (Medicago sativa. But when elevated temperature (eT conditions are applied in tandem with eCO2, a more realistic scenario for future climate change, the positive effects of eCO2 on nodulation and BNF in M. sativa are often much reduced. Silicon (Si supplementation of M. sativa has also been reported to promote root nodulation and BNF, so could potentially restore the positive effects of eCO2 under eT. Increased nitrogen availability, however, could also increase host suitability for aphid pests, potentially negating any benefit. We applied eCO2 (+240 ppm and eT (+4°C, separately and in combination, to M. sativa growing in Si supplemented (Si+ and un-supplemented soil (Si- to determine whether Si moderated the effects of eCO2 and eT. Plants were either inoculated with the aphid Acyrthosiphon pisum or insect-free. In Si- soils, eCO2 stimulated plant growth by 67% and nodulation by 42%, respectively, whereas eT reduced these parameters by 26 and 48%, respectively. Aphids broadly mirrored these effects on Si- plants, increasing colonization rates under eCO2 and performing much worse (reduced abundance and colonization under eT when compared to ambient conditions, confirming our hypothesized link between root nodulation, plant growth, and pest performance. Examined across all CO2 and temperature regimes, Si supplementation promoted plant growth (+93%, and root nodulation (+50%. A. pisum abundance declined sharply under eT conditions and was largely unaffected by Si supplementation. In conclusion, supplementing M. sativa with Si had consistent positive effects on plant growth and nodulation under different CO2 and temperature scenarios. These findings offer potential for using Si supplementation to maintain legume productivity under predicted climate change scenarios

  2. The Medicago truncatula DMI1 protein modulates cytosolic calcium signaling

    DEFF Research Database (Denmark)

    Peiter, Edgar; Sun, Jongho; Heckmann, Anne Birgitte Lau

    2007-01-01

    In addition to establishing symbiotic relationships with arbuscular mycorrhizal fungi, legumes also enter into a nitrogen-fixing symbiosis with rhizobial bacteria that results in the formation of root nodules. Several genes involved in the development of both arbuscular mycorrhiza and legume nodu...

  3. Long-distance transport of signals during symbiosis

    Science.gov (United States)

    Xie, Zhi-Ping; Illana, Antonio

    2011-01-01

    Legumes enter nodule symbioses with nitrogen-fixing bacteria (rhizobia), whereas most flowering plants establish symbiotic associations with arbuscular mycorrhizal (AM) fungi. Once first steps of symbiosis are initiated, nodule formation and mycorrhization in legumes is negatively controlled by a shoot-derived inhibitor (SDI), a phenomenon termed autoregulation. According to current views, autoregulation of nodulation and mycorrhization in legumes is regulated in a similar way. CLE peptides induced in response to rhizobial nodulation signals (Nod factors) have been proposed to represent the ascending long-distance signals to the shoot. Although not proven yet, these CLE peptides are likely perceived by leucine-rich repeat (LRR) autoregulation receptor kinases in the shoot. Autoregulation of mycorrhization in non-legumes is reminiscent to the phenomenon of “systemic acquired resistance” in plant-pathogen interactions. PMID:21455020

  4. The Very Long Chain Fatty Acid (C26:25OH Linked to the Lipid A Is Important for the Fitness of the Photosynthetic Bradyrhizobium Strain ORS278 and the Establishment of a Successful Symbiosis with Aeschynomene Legumes

    Directory of Open Access Journals (Sweden)

    Nicolas Busset

    2017-09-01

    Full Text Available In rhizobium strains, the lipid A is modified by the addition of a very long-chain fatty acid (VLCFA shown to play an important role in rigidification of the outer membrane, thereby facilitating their dual life cycle, outside and inside the plant. In Bradyrhizobium strains, the lipid A is more complex with the presence of at least two VLCFAs, one covalently linked to a hopanoid molecule, but the importance of these modifications is not well-understood. In this study, we identified a cluster of VLCFA genes in the photosynthetic Bradyrhizobium strain ORS278, which nodulates Aeschynomene plants in a Nod factor-independent process. We tried to mutate the different genes of the VLCFA gene cluster to prevent the synthesis of the VLCFAs, but only one mutant in the lpxXL gene encoding an acyltransferase was obtained. Structural analysis of the lipid A showed that LpxXL is involved in the transfer of the C26:25OH VLCFA to the lipid A but not in the one of the C30:29OH VLCFA which harbors the hopanoid molecule. Despite maintaining the second VLCFA, the ability of the mutant to cope with various stresses (low pH, high temperature, high osmolarity, and antimicrobial peptides and to establish an efficient nitrogen-fixing symbiosis was drastically reduced. In parallel, we investigated whether the BRADO0045 gene, which encodes a putative acyltransferase displaying a weak identity with the apo-lipoprotein N-acyltransferase Lnt, could be involved in the transfer of the C30:29OH VLCFA to the lipid A. Although the mutant exhibited phenotypes similar to the lpxXL mutant, no difference in the lipid A structure was observed from that in the wild-type strain, indicating that this gene is not involved in the modification of lipid A. Our results advance our knowledge of the biosynthesis pathway and the role of VLCFAs-modified lipid A in free-living and symbiotic states of Bradyrhizobium strains.

  5. Legume root symbioses: Natural history and prospects for improvement

    Directory of Open Access Journals (Sweden)

    Shtark Oksana

    2011-01-01

    Full Text Available Legumes develop different mutually beneficial microbial-root symbioses such as arbuscular mysorrhiza (AM, rhizobium-legume symbiosis (RLS and epiphytic or endophytic associations with plant growth-promoting bacteria (PGPB which are distinguished in level of integration of the partners. Evidences of the role of AM as ancestral form of symbiosis which might be a source of the legume pre-adaptation to form some RLS are demonstrated. The RLS is supposed to evolve for a few times in ancient legumes in parallel ways based on the universal organization and regulatory mechanisms of the plant genetic material. Associations of plant roots with PGPB probably are the vestige of the early stages of evolution in morphologically differentiated RLS. Also, it is quite possible that 'first' rhizobia have originated from bacterial endosymbionts of AM fungi; then AM fungi might operate as effective vectors for introducing bacteria into the plants. Thus, the legume root symbioses may be considered as a single 'evolutionary plant-microbial continuum'. The acquired knowledge about evolution of plantmicrobe symbioses would contribute to the creation of new commercial varieties of plants with the use of both bio-engineered methods and traditional plant breeding. An original conception of legume breeding to improve their symbiotic effectiveness is proposed.

  6. Organising urban symbiosis projects

    NARCIS (Netherlands)

    Vernay, A.L.; Mulder, K.F.

    2016-01-01

    Urban symbiosis is a strategy to create a more efficient metabolism of cities. However, urban symbiosis requires the integration of different systems, which is hard to achieve. Actors involved in existing systems can hardly develop ‘the bridges’ that are required to connect the thus far unrelated

  7. NIN is involved in the regulation of Arbuscular Mycorrhizal symbiosis.

    Directory of Open Access Journals (Sweden)

    Bruno GUILLOTIN

    2016-11-01

    Full Text Available Arbuscular mycorrhizal (AM symbiosis is an intimate and ancient symbiosis found between most of terrestrial plants and fungi from the Glomeromycota family. Later during evolution, the establishment of the nodulation between legume plants and soil bacteria known as rhizobia, involved several genes of the signalling pathway previously implicated for AM symbiosis. For the past years, the identification of the genes belonging to this Common Symbiotic Signalling Pathway have been mostly done on nodulation. Among the different genes already well identified as required for nodulation, we focused our attention on the involvement of Nodule Inception (NIN in AM symbiosis. We show here that NIN expression is induced during AM symbiosis, and that the Medicago truncatula nin mutant is less colonized than the wild type M. truncatula strain. Moreover, nin mutant displays a defect in the ability to be infected by the fungus Rhizophagus irregularis. This work brings a new evidence of the common genes involved in overlapping signalling pathways of both nodulation and in AM symbiosis.

  8. MALDI mass spectrometry-assisted molecular imaging of metabolites during nitrogen fixation in the Medicago truncatula-Sinorhizobium meliloti symbiosis.

    Science.gov (United States)

    Ye, Hui; Gemperline, Erin; Venkateshwaran, Muthusubramanian; Chen, Ruibing; Delaux, Pierre-Marc; Howes-Podoll, Maegen; Ané, Jean-Michel; Li, Lingjun

    2013-07-01

    Symbiotic associations between leguminous plants and nitrogen-fixing rhizobia culminate in the formation of specialized organs called root nodules, in which the rhizobia fix atmospheric nitrogen and transfer it to the plant. Efficient biological nitrogen fixation depends on metabolites produced by and exchanged between both partners. The Medicago truncatula-Sinorhizobium meliloti association is an excellent model for dissecting this nitrogen-fixing symbiosis because of the availability of genetic information for both symbiotic partners. Here, we employed a powerful imaging technique - matrix-assisted laser desorption/ionization (MALDI)/mass spectrometric imaging (MSI) - to study metabolite distribution in roots and root nodules of M. truncatula during nitrogen fixation. The combination of an efficient, novel MALDI matrix [1,8-bis(dimethyl-amino) naphthalene, DMAN] with a conventional matrix 2,5-dihydroxybenzoic acid (DHB) allowed detection of a large array of organic acids, amino acids, sugars, lipids, flavonoids and their conjugates with improved coverage. Ion density maps of representative metabolites are presented and correlated with the nitrogen fixation process. We demonstrate differences in metabolite distribution between roots and nodules, and also between fixing and non-fixing nodules produced by plant and bacterial mutants. Our study highlights the benefits of using MSI for detecting differences in metabolite distributions in plant biology. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.

  9. The Influence of the Host Plant Is the Major Ecological Determinant of the Presence of Nitrogen-Fixing Root Nodule Symbiont Cluster II Frankia Species in Soil.

    Science.gov (United States)

    Battenberg, Kai; Wren, Jannah A; Hillman, Janell; Edwards, Joseph; Huang, Liujing; Berry, Alison M

    2017-01-01

    The actinobacterial genus Frankia establishes nitrogen-fixing root nodule symbioses with specific hosts within the nitrogen-fixing plant clade. Of four genetically distinct subgroups of Frankia, cluster I, II, and III strains are capable of forming effective nitrogen-fixing symbiotic associations, while cluster IV strains generally do not. Cluster II Frankia strains have rarely been detected in soil devoid of host plants, unlike cluster I or III strains, suggesting a stronger association with their host. To investigate the degree of host influence, we characterized the cluster II Frankia strain distribution in rhizosphere soil in three locations in northern California. The presence/absence of cluster II Frankia strains at a given site correlated significantly with the presence/absence of host plants on the site, as determined by glutamine synthetase (glnA) gene sequence analysis, and by microbiome analysis (16S rRNA gene) of a subset of host/nonhost rhizosphere soils. However, the distribution of cluster II Frankia strains was not significantly affected by other potential determinants such as host-plant species, geographical location, climate, soil pH, or soil type. Rhizosphere soil microbiome analysis showed that cluster II Frankia strains occupied only a minute fraction of the microbiome even in the host-plant-present site and further revealed no statistically significant difference in the α-diversity or in the microbiome composition between the host-plant-present or -absent sites. Taken together, these data suggest that host plants provide a factor that is specific for cluster II Frankia strains, not a general growth-promoting factor. Further, the factor accumulates or is transported at the site level, i.e., beyond the host rhizosphere. Biological nitrogen fixation is a bacterial process that accounts for a major fraction of net new nitrogen input in terrestrial ecosystems. Transfer of fixed nitrogen to plant biomass is especially efficient via root nodule

  10. A Biosensor-Based Leaf Punch Assay for Glutamine Correlates to Symbiotic Nitrogen Fixation Measurements in Legumes to Permit Rapid Screening of Rhizobia Inoculants under Controlled Conditions.

    Science.gov (United States)

    Thilakarathna, Malinda S; Moroz, Nicholas; Raizada, Manish N

    2017-01-01

    Legumes are protein sources for billions of humans and livestock. These traits are enabled by symbiotic nitrogen fixation (SNF), whereby root nodule-inhabiting rhizobia bacteria convert atmospheric nitrogen (N) into usable N. Unfortunately, SNF rates in legume crops suffer from undiagnosed incompatible/suboptimal interactions between crop varieties and rhizobia strains. There are opportunities to test much large numbers of rhizobia strains if cost/labor-effective diagnostic tests become available which may especially benefit researchers in developing countries. Inside root nodules, fixed N from rhizobia is assimilated into amino acids including glutamine (Gln) for export to shoots as the major fraction (amide-exporting legumes) or as the minor fraction (ureide-exporting legumes). Here, we have developed a new leaf punch based technique to screen rhizobia inoculants for SNF activity following inoculation of both amide exporting and ureide exporting legumes. The assay is based on measuring Gln output using the GlnLux biosensor, which consists of Escherichia coli cells auxotrophic for Gln and expressing a constitutive lux operon. Subsistence farmer varieties of an amide exporter (lentil) and two ureide exporters (cowpea and soybean) were inoculated with different strains of rhizobia under controlled conditions, then extracts of single leaf punches were incubated with GlnLux cells, and light-output was measured using a 96-well luminometer. In the absence of external N and under controlled conditions, the results from the leaf punch assay correlated with 15 N-based measurements, shoot N percentage, and shoot total fixed N in all three crops. The technology is rapid, inexpensive, high-throughput, requires minimum technical expertise and very little tissue, and hence is relatively non-destructive. We compared and contrasted the benefits and limitations of this novel diagnostic assay to methods.

  11. A Biosensor-Based Leaf Punch Assay for Glutamine Correlates to Symbiotic Nitrogen Fixation Measurements in Legumes to Permit Rapid Screening of Rhizobia Inoculants under Controlled Conditions

    Directory of Open Access Journals (Sweden)

    Malinda S. Thilakarathna

    2017-10-01

    Full Text Available Legumes are protein sources for billions of humans and livestock. These traits are enabled by symbiotic nitrogen fixation (SNF, whereby root nodule-inhabiting rhizobia bacteria convert atmospheric nitrogen (N into usable N. Unfortunately, SNF rates in legume crops suffer from undiagnosed incompatible/suboptimal interactions between crop varieties and rhizobia strains. There are opportunities to test much large numbers of rhizobia strains if cost/labor-effective diagnostic tests become available which may especially benefit researchers in developing countries. Inside root nodules, fixed N from rhizobia is assimilated into amino acids including glutamine (Gln for export to shoots as the major fraction (amide-exporting legumes or as the minor fraction (ureide-exporting legumes. Here, we have developed a new leaf punch based technique to screen rhizobia inoculants for SNF activity following inoculation of both amide exporting and ureide exporting legumes. The assay is based on measuring Gln output using the GlnLux biosensor, which consists of Escherichia coli cells auxotrophic for Gln and expressing a constitutive lux operon. Subsistence farmer varieties of an amide exporter (lentil and two ureide exporters (cowpea and soybean were inoculated with different strains of rhizobia under controlled conditions, then extracts of single leaf punches were incubated with GlnLux cells, and light-output was measured using a 96-well luminometer. In the absence of external N and under controlled conditions, the results from the leaf punch assay correlated with 15N-based measurements, shoot N percentage, and shoot total fixed N in all three crops. The technology is rapid, inexpensive, high-throughput, requires minimum technical expertise and very little tissue, and hence is relatively non-destructive. We compared and contrasted the benefits and limitations of this novel diagnostic assay to methods.

  12. Absence of the glutamine-synthetase-linked methylammonium (ammonium)-transport system in the cyanobiont of Cycas-cyanobacterial symbiosis.

    Science.gov (United States)

    Rai, A N; Lindblad, P; Bergman, B

    1986-11-01

    Using the ammonium analogue (14)CH3NH 3 (+) , ammonium transport was studied in the cyanobiont cells freshly isolated from the root nodules of Cycas revoluta. An L-methionine-DL-sulphoximine (MSX)-insensitive ammonium-transport system, which was dependent on membrane potential (ΔΨ), was found in the cyanobiont. However, the cyanobiont was incapable of metabolizing exogenous (14)CH3NH 3 (+) or NH 4 (+) because of the absence of another ammonium-transport system responsible for the uptake of ammonium for assimilation via glutamine synthetase (EC 6.3.1.2). Such a modification seems to be the result of symbiosis because the free-living cultured isolate, Anabaena cycadeae, has been shown to possess both the ammonium-transport systems.

  13. Proteomics and Metabolomics: two emerging areas for legume improvement

    Directory of Open Access Journals (Sweden)

    Abirami eRamalingam

    2015-12-01

    Full Text Available The crop legumes such as chickpea, common bean, cowpea, peanut, pigeonpea, soybean, etc. are important source of nutrition and contribute to a significant amount of biological nitrogen fixation (>20 million tons of fixed nitrogen in agriculture. However, the production of legumes is constrained due to abiotic and biotic stresses. It is therefore imperative to understand the molecular mechanisms of plant response to different stresses and identify key candidate genes regulating tolerance which can be deployed in breeding programs. The information obtained from transcriptomics has facilitated the identification of candidate genes for the given trait of interest and utilizing them in crop breeding programs to improve stress tolerance. However, the mechanisms of stress tolerance are complex due to the influence of multi-genes and post-transcriptional regulations. Furthermore, stress conditions greatly affect gene expression which in turn causes modifications in the composition of plant proteomes and metabolomes. Therefore, functional genomics involving various proteomics and metabolomics approaches have been obligatory for understanding plant stress tolerance. These approaches have also been found useful to unravel different pathways related to plant and seed development as well as symbiosis. Proteome and metabolome profiling using high-throughput based systems have been extensively applied in the model legume species Medicago truncatula and Lotus japonicus, as well as in the model crop legume, soybean, to examine stress signalling pathways, cellular and developmental processes and nodule symbiosis. Moreover, the availability of protein reference maps as well as proteomics and metabolomics databases greatly support research and understanding of various biological processes in legumes. Protein-protein interaction techniques, particularly the yeast two-hybrid system have been advantageous for studying symbiosis and stress signalling in legumes. In

  14. The Symbiosis Interactome: a computational approach reveals novel components, functional interactions and modules in Sinorhizobium meliloti

    Directory of Open Access Journals (Sweden)

    Rodriguez-Llorente Ignacio

    2009-06-01

    Full Text Available Abstract Background Rhizobium-Legume symbiosis is an attractive biological process that has been studied for decades because of its importance in agriculture. However, this system has undergone extensive study and although many of the major factors underpinning the process have been discovered using traditional methods, much remains to be discovered. Results Here we present an analysis of the 'Symbiosis Interactome' using novel computational methods in order to address the complex dynamic interactions between proteins involved in the symbiosis of the model bacteria Sinorhizobium meliloti with its plant hosts. Our study constitutes the first large-scale analysis attempting to reconstruct this complex biological process, and to identify novel proteins involved in establishing symbiosis. We identified 263 novel proteins potentially associated with the Symbiosis Interactome. The topology of the Symbiosis Interactome was used to guide experimental techniques attempting to validate novel proteins involved in different stages of symbiosis. The contribution of a set of novel proteins was tested analyzing the symbiotic properties of several S. meliloti mutants. We found mutants with altered symbiotic phenotypes suggesting novel proteins that provide key complementary roles for symbiosis. Conclusion Our 'systems-based model' represents a novel framework for studying host-microbe interactions, provides a theoretical basis for further experimental validations, and can also be applied to the study of other complex processes such as diseases.

  15. Morphogenesis of root nodules in white clover. II. The effect of mutation in genes nod IJ of the microsymbiont upon the nodule structure

    Directory of Open Access Journals (Sweden)

    Barbara Łotocka

    2014-01-01

    Full Text Available Morphogenesis of ineffective root nodules initiated on the roots of white clover 'Astra' by the Rhizobium leguminosarum biovar. trifolii strains ANU261 (Tn5 insertion in nod 1 gene and ANU262 (Tn5 insertion in nod J gene was investigated. Following changes were observed, as compared to the wild-type nodulation: the exaggerated, not delayed reaction of root hairs; the delay in nodulation with the number of nodules the same as in plants inoculated with a wild strain; the formation and organization of the nodule primordium not changed in comparison with the wild-type nodules; infection threads abnormally branched and diffusing with bacteria deprived of light zone and enriched with storage material; infected cells of bacteroidal tissue abnormally strongly osmiophilic and only slightly vacuolated; symbiosomes with very narrowed peribacteroidal space, subject to premature degradation; abnormal accumulation of starch in the nodule tissues; nodule development blocked at the stage of laterally situated meristem and single nodule bundle; inhibition of divisions in the meristem and vacuolation of its cells; the appearance of single cells with colonies of saprophytic rhizobia embedded in the fibrillar matrix in the old, degraded regions of the bacteroidal tissue.

  16. Nod factor signaling and infection in Rhizobium-legume symbiosis

    NARCIS (Netherlands)

    Smit, P.E.J.

    2007-01-01

    Plants require nutrients in order to grow. Most of these are readily available, but a few, like the macronutrients nitrogen and phosphorous, are often limiting growth due to presence in low concentrations or in complexes that cannot be taken up by the plant root. To acquire these macronutrients

  17. Differentiation as symbiosis.

    Science.gov (United States)

    Chigira, M; Watanabe, H

    1994-07-01

    Preservation of the identity of DNA is the ultimate goal of multicellular organisms. An abnormal DNA sequence in cells within an individual means its parasitic nature in cell society as shown in tumors. Somatic gene arrangement and gene mutation in development may be considered as de novo formation of parasites. It is likely that the developmental process with genetic alterations means symbiosis between altered cells and germ line cells preserving genetic information without alterations, when somatic alteration of DNA sequence is a major mechanism of differentiation. According to the selfish gene theory of Dawkins, germ line cells permit symbiosis when somatic cell society derives clear profit for the replication of original DNA copies.

  18. Molecular diversity of rhizobia nodulating the invasive legume Cytisus scoparius in Australia.

    Science.gov (United States)

    Lafay, B; Burdon, J J

    2006-06-01

    To contribute to the understanding of Cytisus scoparius success at invading and establishing itself in Australia. Root-nodule bacteria isolated from C. scoparius, growing on five different sites and originally introduced to Australia, were compared with isolates from indigenous plants growing in France and isolates from native legumes growing on the same Australian sites as C. scoparius. Small-subunit rDNA from 251 isolates were analysed by PCR-RFLP and representatives from different genospecies were selected for sequencing. Phylogenetic analyses revealed a great diversity of lineages belonging to Bradyrhizobium, with one genospecies being specific for Cytisus both in Australia and in France, Rhizobium and Mesorhizobium and one falling outside the described genera of legume-nodulating bacteria. Principal component analysis showed that the Cytisus Australian rhizobial communities are more similar to each other than to their co-occurring native partners. Early established rhizobial symbionts may have an increased probability to contribute inoculum for the development of further nodules. This is a first report comparing rhizobia nodulating C. scoparius in its native and exotic environments. Cytisus scoparius symbionts were identified outside the Bradyrhizobium genus and a new lineage of legume-nodulating bacteria was identified.

  19. Evolution of a symbiotic receptor through gene duplications in the legume-rhizobium mutualism

    NARCIS (Netherlands)

    Mita, De S.; Streng, A.; Bisseling, T.; Geurts, R.

    2014-01-01

    •The symbiosis between legumes and nitrogen-fixing rhizobia co-opted pre-existing endomycorrhizal features. In particular, both symbionts release lipo-chitooligosaccharides (LCOs) that are recognized by LysM-type receptor kinases. We investigated the evolutionary history of rhizobial LCO receptor

  20. PCR Analysis of "expR" Gene Regulating Biosynthesis of Exopolysaccharides in "Sinorhizobium Meliloti"

    Science.gov (United States)

    Sorroche, Fernando G.; Giordano, Walter

    2012-01-01

    Exopolysaccharide (EPS) production by the rhizobacterium "Sinorhizobium meliloti" is essential for root nodule formation on its legume host (alfalfa), and for establishment of a nitrogen-fixing symbiosis between the two partners. Production of EPS II (galactoglucan) by certain "S. meliloti" strains results in a mucoid colony…

  1. Nod factor receptors form heteromeric complexes and are essential for intracellular infection in Medicago nodules

    NARCIS (Netherlands)

    Moling, S.; Pietraszewska-Bogiel, A.; Postma, M.; Fedorova, E.E.; Hink, M.A.; Limpens, E.H.M.; Gadella, T.W.J.; Bisseling, T.

    2014-01-01

    Rhizobial Nod factors are the key signaling molecules in the legume-rhizobium nodule symbiosis. In this study, the role of the Nod factor receptors NOD FACTOR PERCEPTION (NFP) and LYSIN MOTIF RECEPTOR-LIKE KINASE3 (LYK3) in establishing the symbiotic interface in root nodules was investigated. It

  2. Nod factor receptors form heteromeric complexes and are essential for intracellular infection in medicago nodules

    NARCIS (Netherlands)

    Moling, S.; Pietraszewska-Bogiel, A.; Postma, M.; Fedorova, E.; Hink, M.A.; Limpens, E.; Gadella, T.W.J.; Bisseling, T.

    2014-01-01

    Rhizobial Nod factors are the key signaling molecules in the legume-rhizobium nodule symbiosis. In this study, the role of the Nod factor receptors NOD FACTOR PERCEPTION (NFP) and LYSIN MOTIF RECEPTOR-LIKE KINASE3 (LYK3) in establishing the symbiotic interface in root nodules was investigated. It

  3. Human Machine Learning Symbiosis

    Science.gov (United States)

    Walsh, Kenneth R.; Hoque, Md Tamjidul; Williams, Kim H.

    2017-01-01

    Human Machine Learning Symbiosis is a cooperative system where both the human learner and the machine learner learn from each other to create an effective and efficient learning environment adapted to the needs of the human learner. Such a system can be used in online learning modules so that the modules adapt to each learner's learning state both…

  4. Survival through Symbiosis.

    Science.gov (United States)

    Abdi, S. Wali

    1992-01-01

    Describes symbiosis and its significance in the day-to-day lives of plants and animals. Gives specific examples of mutualism, commensalism, and parasitism in the relationships among fungus and plant roots, animals and bacteria, birds and animals, fish, and predator and prey. (MDH)

  5. Symbiotic ß-proteobacteria beyond legumes: Burkholderia in Rubiaceae.

    Directory of Open Access Journals (Sweden)

    Brecht Verstraete

    Full Text Available Symbiotic ß-proteobacteria not only occur in root nodules of legumes but are also found in leaves of certain Rubiaceae. The discovery of bacteria in plants formerly not implicated in endosymbiosis suggests a wider occurrence of plant-microbe interactions. Several ß-proteobacteria of the genus Burkholderia are detected in close association with tropical plants. This interaction has occurred three times independently, which suggest a recent and open plant-bacteria association. The presence or absence of Burkholderia endophytes is consistent on genus level and therefore implies a predictive value for the discovery of bacteria. Only a single Burkholderia species is found in association with a given plant species. However, the endophyte species are promiscuous and can be found in association with several plant species. Most of the endophytes are part of the plant-associated beneficial and environmental group, but others are closely related to B. glathei. This soil bacteria, together with related nodulating and non-nodulating endophytes, is therefore transferred to a newly defined and larger PBE group within the genus Burkholderia.

  6. PGPRs and nitrogen-fixing legumes: a perfect team for efficient Cd phytoremediation?

    Science.gov (United States)

    Gómez-Sagasti, María T; Marino, Daniel

    2015-01-01

    Cadmium (Cd) is a toxic, biologically non-essential and highly mobile metal that has become an increasingly important environmental hazard to both wildlife and humans. In contrast to conventional remediation technologies, phytoremediation based on legume-rhizobia symbiosis has emerged as an inexpensive decontamination alternative which also revitalize contaminated soils due to the role of legumes in nitrogen cycling. In recent years, there is a growing interest in understanding symbiotic legume-rhizobia relationship and its interactions with Cd. The aim of the present review is to provide a comprehensive picture of the main effects of Cd in N2-fixing leguminous plants and the benefits of exploiting this symbiosis together with plant growth promoting rhizobacteria to boost an efficient reclamation of Cd-contaminated soils.

  7. Rhizobia symbiosis of seven leguminous species growing along Xindian riverbank of Northern Taiwan

    Directory of Open Access Journals (Sweden)

    Cheng-Tai Huang

    2018-01-01

    Full Text Available Legume-rhizobia symbioses of seven leguminous species growing along Xindian riverbank of Northern Taiwan were investigated in this study. These legumes form either determinate or indeterminate types of root nodules. The determinate nodules of Alysicarpus vaginalis, Desmodium. triflorum, D. heterophyllum, Sesbania cannabina and the indeterminate nodules of Mimosa pudica harbored bacteroids of morphological uniformity (length of 1-3 μm, while the indeterminate nodules of Crotalaria zanzibarica and Trifolium repens contained bacteroids of highly pleomorphism (size varying from 1 to 5 μm. The enclosed bacteria were isolated from respective nodules, and twenty slow-growing and nine fast-growing rhizobial isolates were recovered. The slow-growing isolates were classified to the genus Bradyrhizobium based on the 16S rRNA sequences, whereas the fast-growing rhizobia comprise four genera, Neorhizobium, Rhizobium, Cupriavidus and Paraburkholderia. Results of stable isotope analyses revealed that the seven leguminous species had similar and consistently negative δ15N values in leaves (mean of -1.2 ‰, whereas the values were positive (varying from 3.7 to 7.3 ‰ in the nodules. These values were significantly higher in the indeterminate nodules than those in the determinate ones. In addition, variations in the values of leaf δ13C (varying from -29 to -34‰ among the seven legumes were measured, indicating their photosynthetic water use efficiencies were different. This is the first field survey to report the rhizobial diversity and the nutrient relationships of sympatric legume in Taiwan.

  8. An alternative pathway for ureide usage in legumes: enzymatic formation of a ureidoglycolate adduct in Cicer arietinum and Phaseolus vulgaris.

    Science.gov (United States)

    Muñoz, Alfonso; Bannenberg, Gerard L; Montero, Olimpio; Cabello-Díaz, Juan Miguel; Piedras, Pedro; Pineda, Manuel

    2011-01-01

    Ureidoglycolate is an intermediate in the degradation of the ureides, allantoin and allantoate, found in many organisms. In some leguminous plant species these compounds are used to transport recently fixed nitrogen in the root nodules to the aerial parts of the plant. In the present study, it was demonstrated that purified ureidoglycolases from chickpea (Cicer arietinum) and French bean (Phaseolus vulgaris) do not produce glyoxylate, and can use phenylhydrazine as a substrate with K(m) values of 4.0 mM and 8.5 mM, respectively. Furthermore, these enzymes catalyse the transfer of the ureidoglycolyl group to phenylhydrazine to produce ureidoglycolyl phenylhydrazide, which degrades non-enzymatically to glyoxylate phenylhydrazone and urea. This supports their former classification as ureidoglycolate urea-lyases. The enzymatic reaction catalysed by the characterized ureidoglycolases uncovered here can be viewed as a novel type of phenylhydrazine ureidoglycolyl transferase. The implications of these findings for ureide metabolism in legume nitrogen metabolism are discussed.

  9. 2,4-Dichlorophenoxyacetic acid (2,4-D)- and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degrading gene cluster in the soybean root-nodulating bacterium Bradyrhizobium elkanii USDA94.

    Science.gov (United States)

    Hayashi, Shohei; Sano, Tomoki; Suyama, Kousuke; Itoh, Kazuhito

    2016-01-01

    Herbicides 2,4-dichlorophenoxyacetic acid (2,4-D)- and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T)-degrading Bradyrhizobium strains possess tfdAα and/or cadABC as degrading genes. It has been reported that root-nodulating bacteria belonging to Bradyrhizobium elkanii also have tfdAα and cadA like genes but lack the ability to degrade these herbicides and that the cadA genes in 2,4-D-degrading and non-degrading Bradyrhizobium are phylogenetically different. In this study, we identified cadRABCK in the genome of a type strain of soybean root-nodulating B. elkanii USDA94 and demonstrated that the strain could degrade the herbicides when cadABCK was forcibly expressed. cadABCK-cloned Escherichia coli also showed the degrading ability. Because co-spiked phenoxyacetic acid (PAA) could induce the degradation of 2,4-D in B. elkanii USDA94, the lack of degrading ability in this strain was supposed to be due to the low inducing potential of the herbicides for the degrading gene cluster. On the other hand, tfdAα from B. elkanii USDA94 showed little potential to degrade the herbicides, but it did for 4-chlorophenoxyacetic acid and PAA. The 2,4-D-degrading ability of the cad cluster and the inducing ability of PAA were confirmed by preparing cadA deletion mutant. This is the first study to demonstrate that the cad cluster in the typical root-nodulating bacterium indeed have the potential to degrade the herbicides, suggesting that degrading genes for anthropogenic compounds could be found in ordinary non-degrading bacteria. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. Transport processes of the legume symbiosome membrane

    Directory of Open Access Journals (Sweden)

    Victoria C Clarke

    2014-12-01

    Full Text Available The symbiosome membrane (SM is a physical barrier between the host plant and nitrogen-fixing bacteria in the legume-rhizobium symbiosis, and represents a regulated interface for the movement of solutes between the symbionts that is under plant control. The primary nutrient exchange across the SM is the transport of a carbon energy source from plant to bacteroid in exchange for fixed nitrogen. At a biochemical level two channels have been implicated in movement of fixed nitrogen across the SM and a uniporter that transports monovalent dicarboxylate ions has been characterized that would transport fixed carbon. The aquaporin NOD26 may provide a channel for ammonia, but the genes encoding the other transporters have not been identified. Transport of several other solutes, including calcium and potassium, have been demonstrated in isolated symbiosomes, and genes encoding transport systems for the movement of iron, nitrate, sulfate and zinc in nodules have been identified. However, definitively matching transport activities with these genes has proved difficult and many further transport processes are expected on the SM to facilitate the movement of nutrients between the symbionts. Recently, work detailing the SM proteome in soybean has been completed, contributing significantly to the database of known SM proteins. This represents a valuable resource for the identification of transporter protein candidates, some of which may correspond to transport processes previously described, or to novel transport systems in the symbiosis. Putative transporters identified from the proteome include homologues of transporters of sulfate, calcium, peptides and various metal ions. Here we review current knowledge of transport processes of the SM and discuss the requirements for additional transport routes of other nutrients exchanged in the symbiosis, with a focus on transport systems identified through the soybean SM proteome.

  11. Characterizing the Suitability of Selected Indigenous Soil Improving Legumes in a Humid Tropical Environment Using Shoot and Root Attributes

    Directory of Open Access Journals (Sweden)

    Anikwe, MAN.

    2003-01-01

    Full Text Available We studied the biomass accumulation, root length, nodulation, and chemical composition of roots and shoot of ten indigenous soil improving legumes in a humid tropical ecosystem with the view to selecting species for soil improvement programmes. Two cultivars of Vigna unguiculata, and one each of Glycine max, Arachis hypogaea, Crotararia ochroleuca, Cajanus cajan, Pueraria phaseoloides, Lablab purpureus, Mucuna pruriens and Vigna subterranea as treatments were planted in 20 kg pots containing soil from an Oxic paleustalf in Nigeria. The pots were arranged in randomized complete block layout with three replications in a greenhouse at IITA Ibadan, Nigeria. Results from the work show that M. pruriens and C. cajan produced the highest quantity of biomass. Root elongation was highest in M. pruriens whereas A. hypogaea produced the most root nodules with native rhizobia. The highest quantity of nodule dry weight was produced by A. hypogaea and P. phaseoloides whereas most of the legumes except G. max and P. phaseoloides had high and statistically comparable N content of between 2.36 and 3.34 mg.kg-1 N. The results show that the legumes have different root and shoot characteristics, which should be taken into consideration when selecting species for soil improvement programmes.

  12. Quantitative evaluation of acidity tolerance of root nodule bacteria Avaliação quantitativa da tolerância de rizóbios à acidez

    Directory of Open Access Journals (Sweden)

    Luiz Antonio de Oliveira

    1999-07-01

    Full Text Available Quantification of acidity tolerance in the laboratory may be the first step in rhizobial strain selection for the Amazon region. The present method evaluated rhizobia in Petri dishes with YMA medium at pH 6.5 (control and 4.5, using scores of 1.0 (sensitive, "no visible" growth to 4.0 (tolerant, maximum growth. Growth evaluations were done at 6, 9, 12, 15 and 18 day periods. This method permits preliminary selection of root nodule bacteria from Amazonian soils with statistical precision. Among the 31 rhizobia strains initially tested, the INPA strains 048, 078, and 671 presented scores of 4.0 at both pHs after 9 days of growth. Strain analyses using a less rigorous criterion (growth scores higher than 3.0 included in this highly tolerant group the INPA strains 511, 565, 576, 632, 649, and 658, which grew on the most diluted zone (zone 4 after 9 days. Tolerant strains still must be tested for nitrogen fixation effectiveness, competitiveness for nodule sites, and soil persistence before their recommendation as inoculants.A quantificação da tolerância à acidez em testes de laboratório pode ser o primeiro passo na seleção de estirpes de rizóbios para a Amazônia. O presente método avaliou isolamentos de rizóbios em placas de Petri contendo meio YMA com pHs 6,5 (controle e 4,5, usando notas de 1,0 (sensíveis, sem crescimento visual, até 4,0 (tolerantes, máximo crescimento. As avaliações foram realizadas aos 6, 9, 12, 15 e 18 dias de crescimento. O método permite selecionar preliminarmente, rizóbios isolados de solos da Amazônia, com precisão estatística. Entre as 31 estirpes inicialmente testadas, as estirpes INPA 048, 078 e 671 apresentaram notas iguais a 4,0 em ambos os pHs testados após os 9 dias de crescimento. Ao se analisar as estirpes usando um sistema menos rigoroso (nota de crescimento acima de 3,0, foi possível incluir também neste grupo, as estirpes INPA 511, 565, 576, 632, 649 e 658, que cresceram na zona mais dilu

  13. Mimosoid legume plastome evolution

    NARCIS (Netherlands)

    Dugas, D.V.; Hernandez, David; Koenen, Erik J.M.; Schwarz, Erika; Straub, Shannon; Hughes, C.E.; Jansen, R.K.; Nageswara-Rao, Madhugiri; Staats, Martijn; Trujillo, J.T.; Hajrah, N.H.; Alharbi, N.S.; Al-Malki, A.L.; Sabir, J.S.M.; Bailey, C.D.

    2015-01-01

    The Leguminosae has emerged as a model for studying angiosperm plastome evolution because of its striking diversity of structural rearrangements and sequence variation. However, most of what is known about legume plastomes comes from few genera representing a subset of lineages in subfamily

  14. Burkholderia kirstenboschensis sp. nov. nodulates papilionoid legumes indigenous to South Africa.

    Science.gov (United States)

    Steenkamp, Emma T; van Zyl, Elritha; Beukes, Chrizelle W; Avontuur, Juanita R; Chan, Wai Yin; Palmer, Marike; Mthombeni, Lunghile S; Phalane, Francina L; Sereme, T Karabo; Venter, Stephanus N

    2015-12-01

    Despite the diversity of Burkholderia species known to nodulate legumes in introduced and native regions, relatively few taxa have been formally described. For example, the Cape Floristic Region of South Africa is thought to represent one of the major centres of diversity for the rhizobial members of Burkholderia, yet only five species have been described from legumes occurring in this region and numerous are still awaiting taxonomic treatment. Here, we investigated the taxonomic status of 12 South African root-nodulating Burkholderia isolates from native papilionoid legumes (Hypocalyptus coluteoides, H. oxalidifolius, H. sophoroides and Virgilia oroboides). Analysis of four gene regions (16S rRNA, recA, atpD and rpoB) revealed that the isolates represent a genealogically unique and exclusive assemblage within the genus. Its distinctness was supported by all other aspects of the polyphasic approach utilized, including the genome-based criteria DNA-DNA hybridization (≥70.9%) and average nucleotide identities (≥96%). We accordingly propose the name B. kirstenboschensis sp. nov. for this taxon with isolate Kb15(T) (=LMG 28727(T); =SARC 695(T)) as its type strain. Our data showed that intraspecific genome size differences (≥0.81 Mb) and the occurrence of large DNA regions that are apparently unique to single individuals (16-23% of an isolate's genome) can significantly limit the value of data obtained from DNA-DNA hybridization experiments. Substitution of DNA-DNA hybridization with whole genome sequencing as a prerequisite for the description of Burkholderia species will undoubtedly speed up the pace at which their diversity are documented, especially in hyperdiverse regions such as the Cape Floristic Region. Copyright © 2015 Elsevier GmbH. All rights reserved.

  15. Legume-rhizobium symbiotic promiscuity and effectiveness do not affect plant invasiveness.

    Science.gov (United States)

    Keet, Jan-Hendrik; Ellis, Allan G; Hui, Cang; Le Roux, Johannes J

    2017-06-01

    The ability to fix atmospheric nitrogen is thought to play an important role in the invasion success of legumes. Interactions between legumes and nitrogen-fixing bacteria (rhizobia) span a continuum of specialization, and promiscuous legumes are thought to have higher chances of forming effective symbioses in novel ranges. Using Australian Acacia species in South Africa, it was hypothesized that widespread and highly invasive species will be more generalist in their rhizobial symbiotic requirements and more effective in fixing atmospheric nitrogen compared with localized and less invasive species. To test these hypotheses, eight localized and 11 widespread acacias were examined using next-generation sequencing data for the nodulation gene, nodC , to compare the identity, species richness, diversity and compositional similarity of rhizobia associated with these acacias. Stable isotope analysis was also used to determine levels of nitrogen obtained from the atmosphere via symbiotic nitrogen fixation. No differences were found in richness, diversity and community composition between localized and widespread acacias. Similarly, widespread and localized acacias did not differ in their ability to fix atmospheric nitrogen. However, for some species by site comparisons, significant differences in δ15N isotopic signatures were found, indicating differential symbiotic effectiveness between these species at specific localities. Overall, the results support recent findings that root nodule rhizobial diversity and community composition do not differ between acacias that vary in their invasiveness. Differential invasiveness of acacias in South Africa is probably linked to attributes such as differences in propagule pressure, reasons for (e.g. forestry vs. ornamental) and extent of, plantings in the country.

  16. Experimental evolution of a plant pathogen into a legume symbiont.

    Directory of Open Access Journals (Sweden)

    Marta Marchetti

    2010-01-01

    Full Text Available Rhizobia are phylogenetically disparate alpha- and beta-proteobacteria that have achieved the environmentally essential function of fixing atmospheric nitrogen in symbiosis with legumes. Ample evidence indicates that horizontal transfer of symbiotic plasmids/islands has played a crucial role in rhizobia evolution. However, adaptive mechanisms that allow the recipient genomes to express symbiotic traits are unknown. Here, we report on the experimental evolution of a pathogenic Ralstonia solanacearum chimera carrying the symbiotic plasmid of the rhizobium Cupriavidus taiwanensis into Mimosa nodulating and infecting symbionts. Two types of adaptive mutations in the hrpG-controlled virulence pathway of R. solanacearum were identified that are crucial for the transition from pathogenicity towards mutualism. Inactivation of the hrcV structural gene of the type III secretion system allowed nodulation and early infection to take place, whereas inactivation of the master virulence regulator hrpG allowed intracellular infection of nodule cells. Our findings predict that natural selection of adaptive changes in the legume environment following horizontal transfer has been a major driving force in rhizobia evolution and diversification and show the potential of experimental evolution to decipher the mechanisms leading to symbiosis.

  17. Genetic and Molecular Mechanisms Underlying Symbiotic Specificity in Legume-Rhizobium Interactions

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2018-03-01

    Full Text Available Legumes are able to form a symbiotic relationship with nitrogen-fixing soil bacteria called rhizobia. The result of this symbiosis is to form nodules on the plant root, within which the bacteria can convert atmospheric nitrogen into ammonia that can be used by the plant. Establishment of a successful symbiosis requires the two symbiotic partners to be compatible with each other throughout the process of symbiotic development. However, incompatibility frequently occurs, such that a bacterial strain is unable to nodulate a particular host plant or forms nodules that are incapable of fixing nitrogen. Genetic and molecular mechanisms that regulate symbiotic specificity are diverse, involving a wide range of host and bacterial genes/signals with various modes of action. In this review, we will provide an update on our current knowledge of how the recognition specificity has evolved in the context of symbiosis signaling and plant immunity.

  18. Genome sequence of Ensifer arboris strain LMG 14919T; a microsymbiont of the legume Prosopis chilensis growing in Kosti, Sudan

    Science.gov (United States)

    Reeve, Wayne; Tian, Rui; Bräu, Lambert; Goodwin, Lynne; Munk, Christine; Detter, Chris; Tapia, Roxanne; Han, Cliff; Liolios, Konstantinos; Huntemann, Marcel; Pati, Amrita; Woyke, Tanja; Mavrommatis, Konstantinos; Markowitz, Victor; Ivanova, Natalia; Kyrpides, Nikos; Willems, Anne

    2013-01-01

    Ensifer arboris LMG 14919T is an aerobic, motile, Gram-negative, non-spore-forming rod that can exist as a soil saprophyte or as a legume microsymbiont of several species of legume trees. LMG 14919T was isolated in 1987 from a nodule recovered from the roots of the tree Prosopis chilensis growing in Kosti, Sudan. LMG 14919T is highly effective at fixing nitrogen with P. chilensis (Chilean mesquite) and Acacia senegal (gum Arabic tree or gum acacia). LMG 14919T does not nodulate the tree Leucena leucocephala, nor the herbaceous species Macroptilium atropurpureum, Trifolium pratense, Medicago sativa, Lotus corniculatus and Galega orientalis. Here we describe the features of E. arboris LMG 14919T, together with genome sequence information and its annotation. The 6,850,303 bp high-quality-draft genome is arranged into 7 scaffolds of 12 contigs containing 6,461 protein-coding genes and 84 RNA-only encoding genes, and is one of 100 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) project. PMID:25197433

  19. Genome sequence of Ensifer arboris strain LMG 14919(T); a microsymbiont of the legume Prosopis chilensis growing in Kosti, Sudan.

    Science.gov (United States)

    Reeve, Wayne; Tian, Rui; Bräu, Lambert; Goodwin, Lynne; Munk, Christine; Detter, Chris; Tapia, Roxanne; Han, Cliff; Liolios, Konstantinos; Huntemann, Marcel; Pati, Amrita; Woyke, Tanja; Mavrommatis, Konstantinos; Markowitz, Victor; Ivanova, Natalia; Kyrpides, Nikos; Willems, Anne

    2014-06-15

    Ensifer arboris LMG 14919(T) is an aerobic, motile, Gram-negative, non-spore-forming rod that can exist as a soil saprophyte or as a legume microsymbiont of several species of legume trees. LMG 14919(T) was isolated in 1987 from a nodule recovered from the roots of the tree Prosopis chilensis growing in Kosti, Sudan. LMG 14919(T) is highly effective at fixing nitrogen with P. chilensis (Chilean mesquite) and Acacia senegal (gum Arabic tree or gum acacia). LMG 14919(T) does not nodulate the tree Leucena leucocephala, nor the herbaceous species Macroptilium atropurpureum, Trifolium pratense, Medicago sativa, Lotus corniculatus and Galega orientalis. Here we describe the features of E. arboris LMG 14919(T), together with genome sequence information and its annotation. The 6,850,303 bp high-quality-draft genome is arranged into 7 scaffolds of 12 contigs containing 6,461 protein-coding genes and 84 RNA-only encoding genes, and is one of 100 rhizobial genomes sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) project.

  20. Symbioses with nitrogen-fixing bacteria: nodulation and phylogenetic data across legume genera.

    Science.gov (United States)

    Afkhami, Michelle E; Luke Mahler, D; Burns, Jean H; Weber, Marjorie G; Wojciechowski, Martin F; Sprent, Janet; Strauss, Sharon Y

    2018-02-01

    How species interactions shape global biodiversity and influence diversification is a central - but also data-hungry - question in evolutionary ecology. Microbially based mutualisms are widespread and could cause diversification by ameliorating stress and thus allowing organisms to colonize and adapt to otherwise unsuitable habitats. Yet the role of these interactions in generating species diversity has received limited attention, especially across large taxonomic groups. In the massive angiosperm family Leguminosae, plants often associate with root-nodulating bacteria that ameliorate nutrient stress by fixing atmospheric nitrogen. These symbioses are ecologically-important interactions, influencing community assembly, diversity, and succession, contributing ~100-290 million tons of N annually to natural ecosystems, and enhancing growth of agronomically-important forage and crop plants worldwide. In recent work attempting to determine whether mutualism with N-fixing bacteria led to increased diversification across legumes, we were unable to definitively resolve the relationship between diversification and nodulation. We did, however, succeed in compiling a very large searchable, analysis-ready database of nodulation data for 749 legume genera (98% of Leguminosae genera; LPWG 2017), which, along with associated phylogenetic information, will provide a valuable resource for future work addressing this question and others. For each legume genus, we provide information about the species richness, frequency of nodulation, subfamily association, and topological correspondence with an additional data set of 100 phylogenetic trees curated for database compatibility. We found 386 legume genera were confirmed nodulators (i.e., all species examined for nodulation nodulated), 116 were non-nodulating, four were variable (i.e., containing both confirmed nodulators and confirmed non-nodulators), and 243 had not been examined for nodulation in published studies. Interestingly

  1. A qualitative study of the nodulating ability of legumes of Pakistan

    Directory of Open Access Journals (Sweden)

    Mohammad Athar

    2014-01-01

    Full Text Available Legume-Rhizobium symbiosis accumulates substantial amounts of mineralizable nitrogen which help in ecological rehabilitation of degraded soils and increase the soil fertility in agricultural ecosystem. Nodulation was studied in 72 legume species from various parts of Pakistan. All the species of Papilionoideae and Mimosoideae were nodulated whereas all the species examined in Caesalpinioideae were non-nodulated. Attempts to elicit nodulation in Caesalpinioid species by rhizobial inoculation were not successful and they were accepted as lacking nodulating ability. Nodulation is reported for the first time in 6 species within 3 genera of Mimosoideae and 9 species within 5 genera of Papilionoideae. Majority of the species were abundantly nodulated under natural soil conditions or when grown in uninoculated garden soil indicating distribution of wide range of naturalized rhizobia. The study shows that the wild legumes hold great promise for inclusion in revegetation of denuded and derelict ecosystems.

  2. The value of biodiversity in legume symbiotic nitrogen fixation and nodulation for biofuel and food production.

    Science.gov (United States)

    Gresshoff, Peter M; Hayashi, Satomi; Biswas, Bandana; Mirzaei, Saeid; Indrasumunar, Arief; Reid, Dugald; Samuel, Sharon; Tollenaere, Alina; van Hameren, Bethany; Hastwell, April; Scott, Paul; Ferguson, Brett J

    2015-01-01

    Much of modern agriculture is based on immense populations of genetically identical or near-identical varieties, called cultivars. However, advancement of knowledge, and thus experimental utility, is found through biodiversity, whether naturally-found or induced by the experimenter. Globally we are confronted by ever-growing food and energy challenges. Here we demonstrate how such biodiversity from the food legume crop soybean (Glycine max L. Merr) and the bioenergy legume tree Pongamia (Millettia) pinnata is a great value. Legume plants are diverse and are represented by over 18,000 species on this planet. Some, such as soybean, pea and medics are used as food and animal feed crops. Others serve as ornamental (e.g., wisteria), timber (e.g., acacia/wattle) or biofuel (e.g., Pongamia pinnata) resources. Most legumes develop root organs (nodules) after microsymbiont induction that serve as their habitat for biological nitrogen fixation. Through this, nitrogen fertiliser demand is reduced by the efficient symbiosis between soil Rhizobium-type bacteria and the appropriate legume partner. Mechanistic research into the genetics, biochemistry and physiology of legumes is thus strategically essential for future global agriculture. Here we demonstrate how molecular plant science analysis of the genetics of an established food crop (soybean) and an emerging biofuel P. pinnata feedstock contributes to their utility by sustainable production aided by symbiotic nitrogen fixation. Crown Copyright © 2014. Published by Elsevier GmbH. All rights reserved.

  3. Competition Experiments for Legume Infection Identify Burkholderia phymatum as a Highly Competitive β-Rhizobium

    Directory of Open Access Journals (Sweden)

    Martina Lardi

    2017-08-01

    Full Text Available Members of the genus Burkholderia (β-proteobacteria have only recently been shown to be able to establish a nitrogen-fixing symbiosis with several legumes, which is why they are also referred to as β-rhizobia. Therefore, very little is known about the competitiveness of these species to nodulate different legume host plants. In this study, we tested the competitiveness of several Burkholderia type strains (B. diazotrophica, B. mimosarum, B. phymatum, B. sabiae, B. symbiotica and B. tuberum to nodulate four legumes (Phaseolus vulgaris, Macroptilium atropurpureum, Vigna unguiculata and Mimosa pudica under our closely defined growth conditions. The assessment of nodule occupancy of these species on different legume host plants revealed that B. phymatum was the most competitive strain in the three papilionoid legumes (bean, cowpea and siratro, while B. mimosarum outcompeted the other strains in mimosa. The analysis of phenotypes known to play a role in nodulation competitiveness (motility, exopolysaccharide production and additional in vitro competition assays among β-rhizobial strains suggested that B. phymatum has the potential to be a very competitive legume symbiont.

  4. Bacterial Molecular Signals in the Sinorhizobium fredii-Soybean Symbiosis

    Directory of Open Access Journals (Sweden)

    Francisco J. López-Baena

    2016-05-01

    Full Text Available Sinorhizobium (Ensifer fredii (S. fredii is a rhizobial species exhibiting a remarkably broad nodulation host-range. Thus, S. fredii is able to effectively nodulate dozens of different legumes, including plants forming determinate nodules, such as the important crops soybean and cowpea, and plants forming indeterminate nodules, such as Glycyrrhiza uralensis and pigeon-pea. This capacity of adaptation to different symbioses makes the study of the molecular signals produced by S. fredii strains of increasing interest since it allows the analysis of their symbiotic role in different types of nodule. In this review, we analyze in depth different S. fredii molecules that act as signals in symbiosis, including nodulation factors, different surface polysaccharides (exopolysaccharides, lipopolysaccharides, cyclic glucans, and K-antigen capsular polysaccharides, and effectors delivered to the interior of the host cells through a symbiotic type 3 secretion system.

  5. Healthy food trends -- beans and legumes

    Science.gov (United States)

    Legumes are large, fleshy, colorful plant seeds. Beans, peas, and lentils are all types of legumes. Vegetables such as beans and other legumes are an important source of protein. They are a key food in healthy ...

  6. Bacterial RuBisCO is required for efficient Bradyrhizobium/Aeschynomene symbiosis.

    Directory of Open Access Journals (Sweden)

    Benjamin Gourion

    Full Text Available Rhizobia and legume plants establish symbiotic associations resulting in the formation of organs specialized in nitrogen fixation. In such organs, termed nodules, bacteria differentiate into bacteroids which convert atmospheric nitrogen and supply the plant with organic nitrogen. As a counterpart, bacteroids receive carbon substrates from the plant. This rather simple model of metabolite exchange underlies symbiosis but does not describe the complexity of bacteroids' central metabolism. A previous study using the tropical symbiotic model Aeschynomene indica/photosynthetic Bradyrhizobium sp. ORS278 suggested a role of the bacterial Calvin cycle during the symbiotic process. Herein we investigated the role of two RuBisCO gene clusters of Bradyrhizobium sp. ORS278 during symbiosis. Using gene reporter fusion strains, we showed that cbbL1 but not the paralogous cbbL2 is expressed during symbiosis. Congruently, CbbL1 was detected in bacteroids by proteome analysis. The importance of CbbL1 for symbiotic nitrogen fixation was proven by a reverse genetic approach. Interestingly, despite its symbiotic nitrogen fixation defect, the cbbL1 mutant was not affected in nitrogen fixation activity under free living state. This study demonstrates a critical role for bacterial RuBisCO during a rhizobia/legume symbiotic interaction.

  7. Cellular and molecular-genetic mechanisms of symbiosis and associative interaction of microorganisms with plants in rhizosphere

    Directory of Open Access Journals (Sweden)

    Lioshina L. G.

    2009-02-01

    Full Text Available The review contains the results of research on symbiotic and associative interaction of microorganisms and plants in rhizosphere. A special attention is given to the process of contact association of microorganisms and plants tissues including the concrete molecular structures and dominant role pertaining to protein-carbohydrate interaction. There are common features and distinctions at formation of arbuscular mycorhiza, rhizobia– legume symbiosis and association of non-leguminous plants with Azospirillum

  8. Cellular and molecular-genetic mechanisms of symbiosis and associative interaction of microorganisms with plants in rhizosphere

    OpenAIRE

    Lioshina L. G.

    2009-01-01

    The review contains the results of research on symbiotic and associative interaction of microorganisms and plants in rhizosphere. A special attention is given to the process of contact association of microorganisms and plants tissues including the concrete molecular structures and dominant role pertaining to protein-carbohydrate interaction. There are common features and distinctions at formation of arbuscular mycorhiza, rhizobia– legume symbiosis and association of non-leguminous plants with...

  9. ABUNDANCE AND DIVERSITY OF LEGUME NODULATING RHIZOBIA IN SOILS OF EMBU DISTRICT, KENYA

    Directory of Open Access Journals (Sweden)

    George M Mwenda

    2010-10-01

    Full Text Available A major strategy towards addressing soil fertility depletion is the conservation and sustainable use of rhizobia that are able to fix nitrogen in the soil in association with legumes. The study assessed abundance and diversity of legume nodulating rhizobia (LNB in soils collected from six different land use systems in Embu District, Kenya. The populations were estimated by the most-probable-number (MPN plant infection technique using Macroptilium atropurpureum (DC. Urban (Siratro as the trap host species. Symbiotic effectiveness was measured for the isolates in association with Siratro. Isolated rhizobia were characterized morphologically and genetically by PCR-RFLP and partial sequencing of 16S rRNA genes. The LNB populations in soils collected from the different land uses in Embu ranged from 0 to 2.3 ï‚´ 102 cells g-1 soil. There was apparent land use effect on abundance of LNB with fallow system giving high abundance. A total of 250 pure isolates were obtained from the root nodules of Siratro trap plants. The isolates were characterized on yeast extract mannitol mineral salts agar (YEMA media containing bromothymol blue and grouped into fast growers (acid-producing and slow growers (alkali-producing (70% and 30 % of isolates respectively. PCR-RFLP analysis categorised the rhizobia into five species in the genera Rhizobium, Bradyrhizobium, Mesorhizobium and Agrobacterium. Land use system under tea had four of the five species found in the area whereas natural forests had two species. Land use significantly impacted on the diversity of rhizobia (P

  10. Functional domain analysis of the Remorin protein LjSYMREM1 in Lotus japonicus

    DEFF Research Database (Denmark)

    Tóth, Katalin; Stratil, Thomas F; Madsen, Esben B

    2012-01-01

    In legumes rhizobial infection during root nodule symbiosis (RNS) is controlled by a conserved set of receptor proteins and downstream components. MtSYMREM1, a protein of the Remorin family in Medicago truncatula, was shown to interact with at least three receptor-like kinases (RLKs) that are ess......In legumes rhizobial infection during root nodule symbiosis (RNS) is controlled by a conserved set of receptor proteins and downstream components. MtSYMREM1, a protein of the Remorin family in Medicago truncatula, was shown to interact with at least three receptor-like kinases (RLKs...... by the Remorin C-terminal region with its coiled-coil domain while the RLK kinase domains transiently interact in vivo and phosphorylate a residue in the N-terminal region of the LjSYMREM1 protein in vitro. These data provide novel insights into the mechanism of this putative molecular scaffold protein...

  11. Exploiting an ancient signalling machinery to enjoy a nitrogen fixing symbiosis.

    Science.gov (United States)

    Geurts, Rene; Lillo, Alessandra; Bisseling, Ton

    2012-08-01

    For almost a century now it has been speculated that a transfer of the largely legume-specific symbiosis with nitrogen fixing rhizobium would be profitable in agriculture [1,2]. Up to now such a step has not been achieved, despite intensive research in this era. Novel insights in the underlying signalling networks leading to intracellular accommodation of rhizobium as well as mycorrhizal fungi of the Glomeromycota order show extensive commonalities between both interactions. As mycorrhizae symbiosis can be established basically with most higher plant species it raises questions why is it only in a few taxonomic lineages that the underlying signalling network could be hijacked by rhizobium. Unravelling this will lead to insights that are essential to achieve an old dream. Copyright © 2012. Published by Elsevier Ltd.

  12. Biofertilizer for food legumes: Bangladesh

    International Nuclear Information System (INIS)

    2003-01-01

    In Bangladesh grain legumes are the protein meat substitute of the poor, and an integral part of the daily diet. Yet present yields cannot meet demand and every year about 25% of the country's grain legumes' requirements have to be imported at a cost of about US $23 million in hard-earned foreign exchange. This money could easily be saved by increasing production in the country. The Department of Technical Co-operation is sponsoring a programme, with technical support from the Joint FAO/IAEA Division, in Bangladesh to find ways of increasing yields of grain legumes using efficient strains of biofertilizers. (IAEA)

  13. Molecular marker genes for ectomycorrhizal symbiosis

    Science.gov (United States)

    Shiv Hiremath; Carolyn McQuattie; Gopi Podila; Jenise. Bauman

    2013-01-01

    Mycorrhizal symbiosis is a mutually beneficial association very commonly found among most vascular plants. Formation of mycorrhiza happens only between compatible partners and predicting this is often accomplished through a trial and error process. We investigated the possibility of using expression of symbiosis specific genes as markers to predict the formation of...

  14. A novel reef coral symbiosis

    Science.gov (United States)

    Pantos, O.; Bythell, J. C.

    2010-09-01

    Reef building corals form close associations with unicellular microalgae, fungi, bacteria and archaea, some of which are symbiotic and which together form the coral holobiont. Associations with multicellular eukaryotes such as polychaete worms, bivalves and sponges are not generally considered to be symbiotic as the host responds to their presence by forming physical barriers with an active growth edge in the exoskeleton isolating the invader and, at a subcellular level, activating innate immune responses such as melanin deposition. This study describes a novel symbiosis between a newly described hydrozoan ( Zanclea margaritae sp. nov.) and the reef building coral Acropora muricata (= A. formosa), with the hydrozoan hydrorhiza ramifying throughout the coral tissues with no evidence of isolation or activation of the immune systems of the host. The hydrorhiza lacks a perisarc, which is typical of symbiotic species of this and related genera, including species that associate with other cnidarians such as octocorals. The symbiosis was observed at all sites investigated from two distant locations on the Great Barrier Reef, Australia, and appears to be host species specific, being found only in A. muricata and in none of 30 other species investigated at these sites. Not all colonies of A. muricata host the hydrozoans and both the prevalence within the coral population (mean = 66%) and density of emergent hydrozoan hydranths on the surface of the coral (mean = 4.3 cm-2, but up to 52 cm-2) vary between sites. The form of the symbiosis in terms of the mutualism-parasitism continuum is not known, although the hydrozoan possesses large stenotele nematocysts, which may be important for defence from predators and protozoan pathogens. This finding expands the known A. muricata holobiont and the association must be taken into account in future when determining the corals’ abilities to defend against predators and withstand stress.

  15. Legume and Lotus japonicus Databases

    DEFF Research Database (Denmark)

    Hirakawa, Hideki; Mun, Terry; Sato, Shusei

    2014-01-01

    Since the genome sequence of Lotus japonicus, a model plant of family Fabaceae, was determined in 2008 (Sato et al. 2008), the genomes of other members of the Fabaceae family, soybean (Glycine max) (Schmutz et al. 2010) and Medicago truncatula (Young et al. 2011), have been sequenced. In this sec....... In this section, we introduce representative, publicly accessible online resources related to plant materials, integrated databases containing legume genome information, and databases for genome sequence and derived marker information of legume species including L. japonicus...

  16. Browses (legume-legume mixture) as dry season feed ...

    African Journals Online (AJOL)

    Increasing competition between man and animals(monogasters, polygasters, microlivestock and wild/feral) for high quality feed(proteinaceous and carbonaceous concentrate) excessive pressure on land from urbanisation , hence the need of multipurpose browse-legumes (Leucaena leucocephala, Gliricidia sepium and ...

  17. Large-scale genetic variation of the symbiosis-required megaplasmid pSymA revealed by comparative genomic analysis of Sinorhizobium meliloti natural strains

    Directory of Open Access Journals (Sweden)

    Landry Christian R

    2005-11-01

    Full Text Available Abstract Background Sinorhizobium meliloti is a soil bacterium that forms nitrogen-fixing nodules on the roots of leguminous plants such as alfalfa (Medicago sativa. This species occupies different ecological niches, being present as a free-living soil bacterium and as a symbiont of plant root nodules. The genome of the type strain Rm 1021 contains one chromosome and two megaplasmids for a total genome size of 6 Mb. We applied comparative genomic hybridisation (CGH on an oligonucleotide microarrays to estimate genetic variation at the genomic level in four natural strains, two isolated from Italian agricultural soil and two from desert soil in the Aral Sea region. Results From 4.6 to 5.7 percent of the genes showed a pattern of hybridisation concordant with deletion, nucleotide divergence or ORF duplication when compared to the type strain Rm 1021. A large number of these polymorphisms were confirmed by sequencing and Southern blot. A statistically significant fraction of these variable genes was found on the pSymA megaplasmid and grouped in clusters. These variable genes were found to be mainly transposases or genes with unknown function. Conclusion The obtained results allow to conclude that the symbiosis-required megaplasmid pSymA can be considered the major hot-spot for intra-specific differentiation in S. meliloti.

  18. Impacts of legume-related policy scenarios

    NARCIS (Netherlands)

    Helming, J.F.M.; Kuhlman, T.; Linderhof, V.G.M.; Oudendag, D.A.

    2014-01-01

    Legume-supported cropping systems for Europe (Legume Futures) is an international research project funded by the European Union through the Framework 7 Programme (FP7) under grant agreement number 245216 (FP7-KBBE-2009-3). The Legume Futures research consortium comprises 20 partners in 13 countries.

  19. Asparagine: an amide of particular distinction in the regulation of symbiotic nitrogen fixation of legumes.

    Science.gov (United States)

    Sulieman, Saad; Tran, Lam-Son Phan

    2013-09-01

    Symbiotic nitrogen fixation is tightly regulated by a range of fine processes at the nodule level, over which the host plant has overall control through the whole life of the plant. The operation of this control at the nodule level is not yet fully understood, but greater knowledge will ultimately lead to a better improvement of N2 fixation through the use of crop legumes and genetic engineering of crop plants for higher performance. It has been suggested that, nodule responses to the nutritional complexity of the rhizosphere environment involve a great deal of coordination of sensing and signal transduction. This regulation can be achieved through several mechanisms, including changes in carbon metabolism, oxygen supply and/or overproduction of reactive oxygen and nitrogen species. Recently, the cycling of amino acids observed between the plant and bacteroid fractions suggests a new and important regulatory mechanism involved in nodule responses. Most of the recent transcriptional findings are consistent with the earlier biochemical and physiological reports. Current research revealed unique advances for nodule metabolism, especially on the regulation of asparagine synthetase gene expression and the control of asparagine (ASN) to N2 fixing activity. A large amount of ASN is found accumulating in the root nodules of the symbiotic plants under restricted environments, such as drought, salinity and nutrient deficiency. Exceptionally, ASN phloem feeding has resulted in an increased concentration of the ASN amide in nodules followed by a remarkable decrease in nodule activity. In this review, recent progress concerning the possible role of ASN in whole-plant-based down-regulation of symbiotic N2 fixation will be reviewed.

  20. THE POSSIBILITY OF LEGUMES PRODUCTION

    Directory of Open Access Journals (Sweden)

    Glinushkin A.P.

    2013-10-01

    Full Text Available Primary receptacles improve profitability legumes are limiting demonstrations and acts of plant diseases and pests. Pathogens are 25-50% lower yield of soybean, chickpea, beans, peas. Pests focally up to 87% of viable seeds sown reduce the number of plants per 1 ha. Only effective protection against disease and estimates of crop production can increase the average profitability of legume crops by 15-30%. Livestock is very important, but in the Southern Urals requires real support for its production with a positive balance (in the calculations with a deviation of 5%. The most important resource in our opinion may be a reduction in price of fodder. Thus, legumes are sought for animal protein. Soybeans, chickpeas, beans, peas universal culture and the possibility of their use in the food balance for a healthy diet of ordinary people engaged in recreational and other sports niche expands further improve the profitability of their production. Regulation of the balance of the distribution of food and feed produced grain legumes allows fine regulation of the cost of fodder for a particular type of livestock activities. Phytosanitary capabilities , the balance of influence of legumes on arable land, also requires a fine regulation of these processes. Obtaining long-term public support for this production is unlikely in the WTO because actual search for ways to improve the profitability of production of agricultural technologies. In our view, a comprehensive approach taking into account the capacity of local markets for crop production. Such activity can act as a guaranteed quality of agro-technology and animal products from local resources specific zonal conditions of production.

  1. Nitrogen fixation is not the only trait that determines the success of tropical legumes during secondary succession

    Science.gov (United States)

    Gei, Maria G.; Powers, Jennifer S.

    2017-04-01

    Legumes trees are well represented throughout the entire precipitation gradient of tropical forests. Many of these species are able to fix atmospheric dinitrogen through symbiosis and offer a mechanism to overcome nitrogen limitation typical of initial stages of secondary forest succession. While it is often assumed the success of legumes is linked to their fixation ability, the variation of other functional traits within this large group has received considerably less attention. Here we assessed legume abundance in secondary forest plots in 42 Neotropical chronosequences (the 2ndFOR network) that span a broad gradient of precipitation regimes and identified those traits that are favored in distinct successional environments. Our main finding is that in young secondary dry forests (5-20 years), legumes that have the potential to fix nitrogen and have small leaflet size become exceptionally abundant (up to 17-99% relative basal area). We suggest that in those species, reduced leaf area could help regulate leaf temperature and minimize water loss, and the cost of reduced total leaf area may be compensated by high photosynthetic rates maximized with nitrogen obtained through fixation. Overall, our study underscores great functional heterogeneity within tropical legumes, which likely translates into diverse biogeochemical cycles. In addition, these results provide a useful framework for active restoration of degraded areas, as it identifies a group of species that accumulate carbon at fast rates under warm and dry environments, conditions that are expected to become more common in the tropics.

  2. Impact of global climate change and fire on the occurrence and function of understorey legumes in forest ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Reverchon, Frederique; Xu, Zhihong; Blumfield, Timothy J.; Chen, Chengrong; Abdullah, Kadum M. [Griffith Univ., Nathan, QLD (Australia). Environmental Futures Centre and School of Biomolecular and Physical Sciences

    2012-02-15

    The objective of this review was to provide a better understanding of how global climate change and fire influence the occurrence of understorey legumes and thereby biological nitrogen (N) fixation rates in forest ecosystems. Legumes are interesting models since they represent an interface between the soil, plant, and microbial compartments, and are directly linked to nutrient cycles through their ability to fix N. As such, they are likely to be affected by environmental changes. Biological N fixation has been shown to increase under enriched CO{sub 2} conditions, but is constrained by the availability of phosphorus and water. Climate change can also influence the species composition of legumes and their symbionts through warming, altered rainfall patterns, or changes in soil physicochemistry, which could modify the effectiveness of the symbiosis. Additionally, global climate change may increase the occurrence and intensity of forest wildfires thereby further influencing the distribution of legumes. The establishment of leguminous species is generally favored by fire, as is N{sub 2} fixation. This fixed N could therefore replenish the N lost through volatilization during the fire. However, fire may also generate shifts in the associated microbial community which could affect the outcome of the symbiosis. Understorey legumes are important functional species, and even when they cannot reasonably be expected to reestablish the nutrient balance in forest soils, they may be used as indicators to monitor nutrient fluxes and the response of forest ecosystems to changing environmental conditions. This would be helpful to accurately model ecosystem N budgets, and since N is often a limiting factor to plant growth and a major constraint on C storage in ecosystems, would allow us to assess more precisely the potential of these forests for C sequestration. (orig.)

  3. Activation of cell divisions in legume nodulation

    DEFF Research Database (Denmark)

    Nadzieja, Marcin

    Leguminous plants engage into symbiotic relationships with soil bacteria, rhizobia, and develop root nodules. This process initiates with recognition of bacteria derived signalling molecules called nod factors. The subsequent events lead to symbiotic infection and, occurring in parallel, de novo...... was shown to require auxin signalling. Cytokinin, in contrast, exert a negative regulation of bacterial entry into the root. During organogenesis, auxin and cytokinin maxima are known to accompany nodule primordia development and together regulate progression through the cell cycle. Moreover, application...... the two hormones require further investigation. In order to improve understanding in these areas we aimed to develop and characterise hormone and cell division markers in Lotus japonicus. Using the extensive genetic resources available in L. japonicus, these markers may then be used to develop a more...

  4. Blue light does not inhibit nodulation in Sesbania rostrata.

    Science.gov (United States)

    Shimomura, Aya; Arima, Susumu; Hayashi, Makoto; Maymon, Maskit; Hirsch, Ann M; Suzuki, Akihiro

    2017-01-02

    Earlier, we reported that root nodulation was inhibited by blue light irradiation of Lotus japonicus. Because some legumes do not establish nodules exclusively on underground roots, we investigated whether nodule formation in Sesbania rostrata, which forms both root and "stem" nodules following inoculation with Azorhizobium caulinodans, is inhibited by blue light as are L. japonicus nodules. We found that neither S. rostrata nodulation nor nitrogen fixation was inhibited by blue light exposure. Moreover, although A. caulinodans proliferation was not affected by blue light irradiation, bacterial survival was decreased. Therefore, blue light appears to impose different responses depending on the legume-rhizobial symbiosis.

  5. Nodulin 41, a novel late nodulin of common bean with peptidase activity

    Directory of Open Access Journals (Sweden)

    Sánchez Federico

    2011-10-01

    Full Text Available Abstract Background The legume-rhizobium symbiosis requires the formation of root nodules, specialized organs where the nitrogen fixation process takes place. Nodule development is accompanied by the induction of specific plant genes, referred to as nodulin genes. Important roles in processes such as morphogenesis and metabolism have been assigned to nodulins during the legume-rhizobium symbiosis. Results Here we report the purification and biochemical characterization of a novel nodulin from common bean (Phaseolus vulgaris L. root nodules. This protein, called nodulin 41 (PvNod41 was purified through affinity chromatography and was partially sequenced. A genomic clone was then isolated via PCR amplification. PvNod41 is an atypical aspartyl peptidase of the A1B subfamily with an optimal hydrolytic activity at pH 4.5. We demonstrate that PvNod41 has limited peptidase activity against casein and is partially inhibited by pepstatin A. A PvNod41-specific antiserum was used to assess the expression pattern of this protein in different plant organs and throughout root nodule development, revealing that PvNod41 is found only in bean root nodules and is confined to uninfected cells. Conclusions To date, only a small number of atypical aspartyl peptidases have been characterized in plants. Their particular spatial and temporal expression patterns along with their unique enzymatic properties imply a high degree of functional specialization. Indeed, PvNod41 is closely related to CDR1, an Arabidopsis thaliana extracellular aspartyl protease involved in defense against bacterial pathogens. PvNod41's biochemical properties and specific cell-type localization, in uninfected cells of the common bean root nodule, strongly suggest that this aspartyl peptidase has a key role in plant defense during the symbiotic interaction.

  6. Does plant immunity play a critical role during initiation of the legume-rhizobium symbiosis?

    OpenAIRE

    T?th, Katalin; Stacey, Gary

    2015-01-01

    Plants are exposed to many different microbes in their habitats. These microbes may be benign or pathogenic, but in some cases they are beneficial for the host. The rhizosphere provides an especially rich palette for colonization by beneficial (associative and symbiotic) microorganisms, which raises the question as to how roots can distinguish such ‘friends’ from possible ‘foes’ (i.e., pathogens). Plants possess an innate immune system that can recognize pathogens, through an arsenal of prote...

  7. Does plant immunity have a central role in the legume rhizobium symbiosis?

    OpenAIRE

    Katalin eToth; Gary eStacey; Gary eStacey

    2015-01-01

    Plants are exposed to many different microbes in their habitat. These microbes may be benign or pathogenic, but in some cases they are beneficial. The rhizosphere provides an especially rich palette for colonization by beneficial (associative and symbiotic) microorganisms, which raises the question as to how roots can distinguish such ‘friends’ from possible ‘foes’ (i.e., pathogens). Plants possess an innate immunity system that can recognize pathogens, through an arsenal of protein receptors...

  8. Rhizobium-legume symbiosis shares an exocytotic pathway required for arbuscle formation

    NARCIS (Netherlands)

    Ivanov, S.; Fedorova, E.E.; Limpens, E.H.M.; Mita, De S.; Genre, A.; Bonfante, P.; Bisseling, T.

    2012-01-01

    Endosymbiotic interactions are characterized by the formation of specialized membrane compartments, by the host in which the microbes are hosted, in an intracellular manner. Two well-studied examples, which are of major agricultural and ecological importance, are the widespread arbuscular

  9. NUTRITIONAL AND HEALTH IMPLICATIONS OF LEGUMES

    OpenAIRE

    Mebrahtom Gebrelibanos*, Dinka Tesfaye, Y. Raghavendra and Biruk Sintayeyu

    2013-01-01

    ABSTRACT: Legumes are plants in the family Fabaceae characterized by seeds in pods that are often edible though sometimes poisonous. The nutrient content (protein, carbohydrate and micronutrients) of legumes contribute to address under-nutrition, especially protein-calorie malnutrition among children and nursing mothers in developing countries where supplementing cereal-based diets with legumes is suggested as one of the best solutions to protein calorie malnutrition. Anti-nutritional factors...

  10. NPR1 Protein Regulates Pathogenic and Symbiotic Interactions between Rhizobium and Legumes and Non-Legumes

    OpenAIRE

    Peleg-Grossman, Smadar; Golani, Yael; Kaye, Yuval; Melamed-Book, Naomi; Levine, Alex

    2009-01-01

    BACKGROUND: Legumes are unique in their ability to establish symbiotic interaction with rhizobacteria from Rhizobium genus, which provide them with available nitrogen. Nodulation factors (NFs) produced by Rhizobium initiate legume root hair deformation and curling that entrap the bacteria, and allow it to grow inside the plant. In contrast, legumes and non-legumes activate defense responses when inoculated with pathogenic bacteria. One major defense pathway is mediated by salicylic acid (SA)....

  11. Phylogenetic clustering of Bradyrhizobium symbionts on legumes indigenous to North America.

    Science.gov (United States)

    Koppell, Jonathan H; Parker, Matthew A

    2012-08-01

    To analyse determinants of biogeographic structure in members of the genus Bradyrhizobium, isolates were obtained from 41 legume genera, originating from North American sites spanning 48.5 ° of latitude (Alaska to Panama). Sequencing of portions of six gene loci (3674 bp) in 203 isolates showed that there was only a weak trend towards higher nucleotide diversity in tropical regions. Phylogenetic relationships for nifD, in the symbiosis island region of the Bradyrhizobium chromosome, conflicted substantially with a tree inferred for five housekeeping gene loci. For both nifD and housekeeping gene trees, bacteria from each region were significantly more similar, on average, than would be expected if the source location was permuted at random on the tree. Within-region permutation tests also showed that bacteria clustered significantly on particular host plant clades at all levels in the phylogeny of legumes (from genus up to subfamily). Nevertheless, some bacterial groups were dispersed across multiple regions and were associated with diverse legume host lineages. These results indicate that migration, horizontal gene transfer and host interactions have all influenced the geographical divergence of Bradyrhizobium populations on a continental scale.

  12. Legume Information System (LegumeInfo.org): a key component of a set of federated data resources for the legume family

    Science.gov (United States)

    The Legume Information System (LIS), at http://legumeinfo.org, is a genomic data portal (GDP) for the legume family. LIS provides access to genetic and genomic information for major crop and model legumes. With more than two-dozen domesticated legume species, there are numerous specialists working o...

  13. Cycling of grain legume residue nitrogen

    DEFF Research Database (Denmark)

    Jensen, E.S.

    1995-01-01

    Symbiotic nitrogen fixation by legumes is the main input of nitrogen in ecological agriculture. The cycling of N-15-labelled mature pea (Pisum sativum L.) residues was studied during three years in small field plots and lysimeters. The residual organic labelled N declined rapidly during the initial...... management methods in order to conserve grain legume residue N sources within the soil-plant system....

  14. Utilization of summer legumes as bioenergy feedstocks

    Science.gov (United States)

    Sunn hemp (Crotolaria juncea), is a fast growing, high biomass yielding tropical legume that may be a possible southeastern bioenergy crop. When comparing this legume to a commonly grown summer legume—cowpeas (Vigna unguiculata), sunn hemp was superior in biomass yield and subsequent energy yield. S...

  15. Legume proteomics: Progress, prospects, and challenges.

    Science.gov (United States)

    Rathi, Divya; Gayen, Dipak; Gayali, Saurabh; Chakraborty, Subhra; Chakraborty, Niranjan

    2016-01-01

    Legumes are the major sources of food and fodder with strong commercial relevance, and are essential components of agricultural ecosystems owing to their ability to carry out endosymbiotic nitrogen fixation. In recent years, legumes have become one of the major choices of plant research. The legume proteomics is currently represented by more than 100 reference maps and an equal number of stress-responsive proteomes. Among the 48 legumes in the protein databases, most proteomic studies have been accomplished in two model legumes, soybean, and barrel medic. This review highlights recent contributions in the field of legume proteomics to comprehend the defence and regulatory mechanisms during development and adaptation to climatic changes. Here, we attempted to provide a concise overview of the progress in legume proteomics and discuss future developments in three broad perspectives: (i) proteome of organs/tissues; (ii) subcellular compartments; and (iii) spatiotemporal changes in response to stress. Such data mining may aid in discovering potential biomarkers for plant growth, in general, apart from essential components involved in stress tolerance. The prospect of integrating proteome data with genome information from legumes will provide exciting opportunities for plant biologists to achieve long-term goals of crop improvement and sustainable agriculture. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. The legume manifesto: (Networkers on Fabaceae, unite!

    Directory of Open Access Journals (Sweden)

    Mikić Aleksandar

    2011-01-01

    Full Text Available Legumes have been an important part of cropping systems since the dawn of agriculture. The shift in Europe from draught animals to meat animals coincided with the increasing availability of soybean meal from North and South America, and the Common Agricultural Policy of the European Union promoted the growing of cereals and oilseeds at the expense of other crops so legumes fell out of favour with farmers and decision-makers. Continental concerns about food and feed security, high prices of oil and soybean meal and advances in the application of fundamental molecular genetics to crop species, all mean that now is a good opportunity to promote the return of legumes to European cropping systems by enhancing the efficiency of research and development on this family. Hence we propose the establishment of a Legume Society that will promote information exchange and scientific productivity by uniting the various legume research communities.

  17. Legume Shrubs Are More Nitrogen-Homeostatic than Non-legume Shrubs

    Science.gov (United States)

    Guo, Yanpei; Yang, Xian; Schöb, Christian; Jiang, Youxu; Tang, Zhiyao

    2017-01-01

    Legumes are characterized as keeping stable nutrient supply under nutrient-limited conditions. However, few studies examined the legumes' stoichiometric advantages over other plants across various taxa in natural ecosystems. We explored differences in nitrogen (N) and phosphorus (P) stoichiometry of different tissue types (leaf, stem, and root) between N2-fixing legume shrubs and non-N2-fixing shrubs from 299 broadleaved deciduous shrubland sites in northern China. After excluding effects of taxonomy and environmental variables, these two functional groups differed considerably in nutrient regulation. N concentrations and N:P ratios were higher in legume shrubs than in non-N2-fixing shrubs. N concentrations were positively correlated between the plants and soil for non-N2-fixing shrubs, but not for legume shrubs, indicating a stronger stoichiometric homeostasis in legume shrubs than in non-N2-fixing shrubs. N concentrations were positively correlated among three tissue types for non-N2-fixing shrubs, but not between leaves and non-leaf tissues for legume shrubs, demonstrating that N concentrations were more dependent among tissues for non-N2-fixing shrubs than for legume shrubs. N and P concentrations were correlated within all tissues for both functional groups, but the regression slopes were flatter for legume shrubs than non-N2-fixing shrubs, implying that legume shrubs were more P limited than non-N2-fixing shrubs. These results address significant differences in stoichiometry between legume shrubs and non-N2-fixing shrubs, and indicate the influence of symbiotic nitrogen fixation (SNF) on plant stoichiometry. Overall, N2-fixing legume shrubs are higher and more stoichiometrically homeostatic in N concentrations. However, due to excess uptake of N, legumes may suffer from potential P limitation. With their N advantage, legume shrubs could be good nurse plants in restoration sites with degraded soil, but their P supply should be taken care of during management

  18. Legume Shrubs Are More Nitrogen-Homeostatic than Non-legume Shrubs

    Directory of Open Access Journals (Sweden)

    Yanpei Guo

    2017-09-01

    Full Text Available Legumes are characterized as keeping stable nutrient supply under nutrient-limited conditions. However, few studies examined the legumes' stoichiometric advantages over other plants across various taxa in natural ecosystems. We explored differences in nitrogen (N and phosphorus (P stoichiometry of different tissue types (leaf, stem, and root between N2-fixing legume shrubs and non-N2-fixing shrubs from 299 broadleaved deciduous shrubland sites in northern China. After excluding effects of taxonomy and environmental variables, these two functional groups differed considerably in nutrient regulation. N concentrations and N:P ratios were higher in legume shrubs than in non-N2-fixing shrubs. N concentrations were positively correlated between the plants and soil for non-N2-fixing shrubs, but not for legume shrubs, indicating a stronger stoichiometric homeostasis in legume shrubs than in non-N2-fixing shrubs. N concentrations were positively correlated among three tissue types for non-N2-fixing shrubs, but not between leaves and non-leaf tissues for legume shrubs, demonstrating that N concentrations were more dependent among tissues for non-N2-fixing shrubs than for legume shrubs. N and P concentrations were correlated within all tissues for both functional groups, but the regression slopes were flatter for legume shrubs than non-N2-fixing shrubs, implying that legume shrubs were more P limited than non-N2-fixing shrubs. These results address significant differences in stoichiometry between legume shrubs and non-N2-fixing shrubs, and indicate the influence of symbiotic nitrogen fixation (SNF on plant stoichiometry. Overall, N2-fixing legume shrubs are higher and more stoichiometrically homeostatic in N concentrations. However, due to excess uptake of N, legumes may suffer from potential P limitation. With their N advantage, legume shrubs could be good nurse plants in restoration sites with degraded soil, but their P supply should be taken care of

  19. Supply chain collaboration in industrial symbiosis networks

    DEFF Research Database (Denmark)

    Herczeg, Gabor; Akkerman, Renzo; Hauschild, Michael Zwicky

    2018-01-01

    A strategy supporting the development towards a circular economy is industrial symbiosis (IS). It is a form of collaborative supply chain management aiming to make industry more sustainable and achieve collective benefits based on utilization of waste, by-products, and excess utilities between...

  20. Supply chain collaboration in industrial symbiosis networks

    NARCIS (Netherlands)

    Herczeg, Gábor; Akkerman, Renzo; Hauschild, Michael Zwicky

    2018-01-01

    A strategy supporting the development towards a circular economy is industrial symbiosis (IS). It is a form of collaborative supply chain management aiming to make industry more sustainable and achieve collective benefits based on utilization of waste, by-products, and excess utilities between

  1. The nitrate-reduction gene cluster components exert lineage-dependent contributions to optimization of Sinorhizobium symbiosis with soybeans.

    Science.gov (United States)

    Liu, Li Xue; Li, Qin Qin; Zhang, Yun Zeng; Hu, Yue; Jiao, Jian; Guo, Hui Juan; Zhang, Xing Xing; Zhang, Biliang; Chen, Wen Xin; Tian, Chang Fu

    2017-12-01

    Receiving nodulation and nitrogen fixation genes does not guarantee rhizobia an effective symbiosis with legumes. Here, variations in gene content were determined for three Sinorhizobium species showing contrasting symbiotic efficiency on soybeans. A nitrate-reduction gene cluster absent in S. sojae was found to be essential for symbiotic adaptations of S. fredii and S. sp. III. In S. fredii, the deletion mutation of the nap (nitrate reductase), instead of nir (nitrite reductase) and nor (nitric oxide reductase), led to defects in nitrogen-fixation (Fix - ). By contrast, none of these core nitrate-reduction genes were required for the symbiosis of S. sp. III. However, within the same gene cluster, the deletion of hemN1 (encoding oxygen-independent coproporphyrinogen III oxidase) in both S. fredii and S. sp. III led to the formation of nitrogen-fixing (Fix + ) but ineffective (Eff - ) nodules. These Fix + /Eff - nodules were characterized by significantly lower enzyme activity of glutamine synthetase indicating rhizobial modulation of nitrogen-assimilation by plants. A distant homologue of HemN1 from S. sojae can complement this defect in S. fredii and S. sp. III, but exhibited a more pleotropic role in symbiosis establishment. These findings highlighted the lineage-dependent optimization of symbiotic functions in different rhizobial species associated with the same host. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  2. Rhizobium sophorae sp. nov. and Rhizobium sophoriradicis sp. nov., nitrogen-fixing rhizobial symbionts of the medicinal legume Sophora flavescens.

    Science.gov (United States)

    Jiao, Yin Shan; Yan, Hui; Ji, Zhao Jun; Liu, Yuan Hui; Sui, Xin Hua; Wang, En Tao; Guo, Bao Lin; Chen, Wen Xin; Chen, Wen Feng

    2015-02-01

    Five bacterial strains representing 45 isolates originated from root nodules of the medicinal legume Sophora flavescens were defined as two novel groups in the genus Rhizobium based on their phylogenetic relationships estimated from 16S rRNA genes and the housekeeping genes recA, glnII and atpD. These groups were distantly related to Rhizobium leguminosarum USDA 2370(T) (95.6 % similarity for group I) and Rhizobium phaseoli ATCC 14482(T) (93.4 % similarity for group II) in multilocus sequence analysis. In DNA-DNA hybridization experiments, the reference strains CCBAU 03386(T) (group I) and CCBAU 03470(T) (group II) showed levels of relatedness of 17.9-57.8 and 11.0-42.9 %, respectively, with the type strains of related species. Both strains CCBAU 03386(T) and CCBAU 03470(T) contained ubiquinone 10 (Q-10) as the major respiratory quinone and possessed 16 : 0, 18 : 0, 19 : 0 cyclo ω8c, summed feature 8 and summed feature 2 as major fatty acids, but did not contain 20 : 3 ω6,8,12c. Phenotypic features distinguishing both groups from all closely related species of the genus Rhizobium were found. Therefore, two novel species, Rhizobium sophorae sp. nov. for group I (type strain CCBAU 03386(T) = E5(T) = LMG 27901(T) = HAMBI 3615(T)) and Rhizobium sophoriradicis sp. nov. for group II (type strain CCBAU 03470(T) = C-5-1(T) = LMG 27898(T) = HAMBI 3510(T)), are proposed. Both groups were able to nodulate Phaseolus vulgaris and their hosts of origin (Sophora flavescens) effectively and their nodulation gene nodC was phylogenetically located in the symbiovar phaseoli. © 2015 IUMS.

  3. Grain legume cultivars derived from induced mutations, and mutations affecting nodulation

    International Nuclear Information System (INIS)

    Bhatia, C.R.; Maluszynski, M.; Nichterlein, K.; Zanten, L. van

    2001-01-01

    Two hundred and sixty-five grain legume cultivars developed using induced mutations have been released in 32 countries. A maximum number of cultivars have been released in soybean (58), followed by common bean (50), groundnut (44), pea (32) and mungbean (14). Gamma or x-ray exposures of seeds led to the direct development of 111 cultivars, while neutron and chemical mutagen treatments resulted in 8 and 36 cultivars respectively. One hundred and three cultivars have been developed using mutants in cross breeding. Attempts have been made to estimate the successful dose range for gamma and x-rays, defined as the dose range, which led to the development, registration and release of a maximum number of mutant cultivars. Exposures to seeds ranging between 100-200 Gy in all grain legumes, except faba bean, resulted in 49 out of 111 cultivars being developed as direct mutants. Successful doses reported for faba bean are lower than 100 Gy. Modified crop plant characters are listed. Besides the development of new cultivars, a large number of induced mutants that show altered nodulation pattern have been isolated in grain legumes. Such mutants have made a significant contribution in basic studies on host-symbiont interactions and towards cloning of plant genes related to symbiosis and nitrogen fixation. Their exploitation in breeding programs for enhancing nitrogen fixation is just beginning. Available information on nodulation mutants in grain legume crops is summarised. Mainly, four types of nodulation mutants have been isolated. They show either: no nodulation (nod -), few nodules (nod +/-), ineffective nodulation (Fix-), hypernodulation (nod ++) or hypernodulation even in the presence of otherwise inhibitory nitrate levels (nts). Hypernodulating and nts mutants are of great interest. A soybean cultivar incorporating nts trait has been released in Australia. (author)

  4. Distinct patterns of symbiosis-related gene expression in actinorhizal nodules from different plant families

    NARCIS (Netherlands)

    Pawlowski, K.; Swensen, S.; Guan, C.; Hadri, A.E.; Berry, A.M.; Bisseling, T.

    2003-01-01

    Phylogenetic analyses suggest that, among the members of the Eurosid I clade, nitrogen-fixing root nodule symbioses developed multiple times independently, four times with rhizobia and four times with the genus Frankia. In order to understand the degree of similarity between symbiotic systems of

  5. [Nod factors, chemical signal exchange between bacteria and leguminous plants in nitrogen fixing symbiosis].

    Science.gov (United States)

    Promé, J C

    1999-05-01

    The early steps of the nitrogen-fixing symbiosis between plant legumes and soil bacteria (rhizobium) are mediated by an exchange of chemical signals between the two partners. Upon gene activation by plant root secretions (flavonoids), bacteria synthesize lipochitooligomers (called Nod Factors, NFs) that induce root hair deformations, cortical cell divisions, allow bacterial entry and produce nodule organogenesis at nano to picomole concentrations. Substitutions occurring on the lipochitooligosaccharide core are essential for recognition and activity. Biosynthesis of these molecules is now fully dissected, by looking at the structural changes in NFs induced by gene mutation or gene transfers. From the biodiversity studies of NFs, it appears that their structures belong with the phylogenetic evolution of plants, rather than that of bacteria, suggesting a coevolution of symbiotic bacteria with their plant receptors. Some preliminary and indirect observations indicate that similar molecules seem to exist in non-legumes plants, in batrachians and fishes beeing possibly involved in their embryogenesis, but they are probably at at a so low concentration that all attempts to detect them directly fail up to now.

  6. Biological Nitrogen Fixation on Legume

    Directory of Open Access Journals (Sweden)

    Armiadi

    2009-03-01

    Full Text Available Nitrogen (N is one of the major limiting factors for crop growth and is required in adequate amount, due to its function as protein and enzyme components. In general, plants need sufficient nitrogen supply at all levels of growth, especially at the beginning of growth phase. Therefore, the availability of less expensive N resources would reduce the production cost. The increasing use of chemical fertilizer would probably disturb soil microorganisms, reduce the physical and chemical characteristics of soil because not all of N based fertilizer applied can be absorbed by the plants. Approximately only 50% can be used by crops, while the rest will be altered by microorganism into unavailable N for crops or else dissappear in the form of gas. Leguminous crops have the capacity to immobilize N2 and convert into the available N if innoculated with Rhizobium. The amount of N2 fixed varies depending on legume species and their environment.

  7. Scent glands in legume flowers.

    Science.gov (United States)

    Marinho, C R; Souza, C D; Barros, T C; Teixeira, S P

    2014-01-01

    Scent glands, or osmophores, are predominantly floral secretory structures that secrete volatile substances during anthesis, and therefore act in interactions with pollinators. The Leguminosae family, despite being the third largest angiosperm family, with a wide geographical distribution and diversity of habits, morphology and pollinators, has been ignored with respect to these glands. Thus, we localised and characterised the sites of fragrance production and release in flowers of legumes, in which scent plays an important role in pollination, and also tested whether there are relationships between the structure of the scent gland and the pollinator habit: diurnal or nocturnal. Flowers in pre-anthesis and anthesis of 12 legume species were collected and analysed using immersion in neutral red, olfactory tests and anatomical studies (light and scanning electron microscopy). The main production site of floral scent is the perianth, especially the petals. The scent glands are distributed in a restricted way in Caesalpinia pulcherrima, Anadenanthera peregrina, Inga edulis and Parkia pendula, constituting mesophilic osmophores, and in a diffuse way in Bauhinia rufa, Hymenaea courbaril, Erythrostemon gilliesii, Poincianella pluviosa, Pterodon pubescens, Platycyamus regnellii, Mucuna urens and Tipuana tipu. The glands are comprised of cells of the epidermis and mesophyll that secrete mainly terpenes, nitrogen compounds and phenols. Relationships between the presence of osmophores and type of anthesis (diurnal and nocturnal) and the pollinator were not found. Our data on scent glands in Leguminosae are original and detail the type of diffuse release, which has been very poorly studied. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  8. Phylogenetic diversity of Rhizobium strains nodulating diverse legume species growing in Ethiopia.

    Science.gov (United States)

    Degefu, Tulu; Wolde-meskel, Endalkachew; Frostegård, Åsa

    2013-06-01

    The taxonomic diversity of thirty-seven Rhizobium strains, isolated from nodules of leguminous trees and herbs growing in Ethiopia, was studied using multilocus sequence analyses (MLSA) of six core and two symbiosis-related genes. Phylogenetic analysis based on the 16S rRNA gene grouped them into five clusters related to nine Rhizobium reference species (99-100% sequence similarity). In addition, two test strains occupied their own independent branches on the phylogenetic tree (AC86a2 along with R. tibeticum; 99.1% similarity and AC100b along with R. multihospitium; 99.5% similarity). One strain from Milletia ferruginea was closely related (>99%) to the genus Shinella, further corroborating earlier findings that nitrogen-fixing bacteria are distributed among phylogenetically unrelated taxa. Sequence analyses of five housekeeping genes also separated the strains into five well-supported clusters, three of which grouped with previously studied Ethiopian common bean rhizobia. Three of the five clusters could potentially be described into new species. Based on the nifH genes, most of the test strains from crop legumes were closely related to several strains of Ethiopian common bean rhizobia and other symbionts of bean plants (R. etli and R. gallicum sv. phaseoli). The grouping of the test strains based on the symbiosis-related genes was not in agreement with the housekeeping genes, signifying differences in their evolutionary history. Our earlier studies revealing a large diversity of Mesorhizobium and Ensifer microsymbionts isolated from Ethiopian legumes, together with the results from the present analysis of Rhizobium strains, suggest that this region might be a potential hotspot for rhizobial biodiversity. Copyright © 2013 Elsevier GmbH. All rights reserved.

  9. Collaborative planning of operations in industrial symbiosis

    DEFF Research Database (Denmark)

    Herczeg, Gabor; Akkerman, Renzo

    2014-01-01

    Industrial symbiosis (IS) is cooperation between companies to achieve collective benefits by supplying and reusing industrial waste to substitute virgin resources in production. In this paper, we investigate the IS phenomenon from a supply chain management perspective. We propose a collaborative...... planning model to coordinate master planning of operations of waste suppliers and buyers. Furthermore, we analyze planning decisions related to IS when waste exchange is combined with virgin resource procurement. We demonstrate that conditions of virgin resource procurement affect the economic feasibility...

  10. Legume information system (LegumeInfo.org): a key component of a set of federated data resources for the legume family.

    Science.gov (United States)

    Dash, Sudhansu; Campbell, Jacqueline D; Cannon, Ethalinda K S; Cleary, Alan M; Huang, Wei; Kalberer, Scott R; Karingula, Vijay; Rice, Alex G; Singh, Jugpreet; Umale, Pooja E; Weeks, Nathan T; Wilkey, Andrew P; Farmer, Andrew D; Cannon, Steven B

    2016-01-04

    Legume Information System (LIS), at http://legumeinfo.org, is a genomic data portal (GDP) for the legume family. LIS provides access to genetic and genomic information for major crop and model legumes. With more than two-dozen domesticated legume species, there are numerous specialists working on particular species, and also numerous GDPs for these species. LIS has been redesigned in the last three years both to better integrate data sets across the crop and model legumes, and to better accommodate specialized GDPs that serve particular legume species. To integrate data sets, LIS provides genome and map viewers, holds synteny mappings among all sequenced legume species and provides a set of gene families to allow traversal among orthologous and paralogous sequences across the legumes. To better accommodate other specialized GDPs, LIS uses open-source GMOD components where possible, and advocates use of common data templates, formats, schemas and interfaces so that data collected by one legume research community are accessible across all legume GDPs, through similar interfaces and using common APIs. This federated model for the legumes is managed as part of the 'Legume Federation' project (accessible via http://legumefederation.org), which can be thought of as an umbrella project encompassing LIS and other legume GDPs. Published by Oxford University Press on behalf of Nucleic Acids Research 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  11. Secondary metabolism in the lichen symbiosis.

    Science.gov (United States)

    Calcott, Mark J; Ackerley, David F; Knight, Allison; Keyzers, Robert A; Owen, Jeremy G

    2018-03-05

    Lichens, which are defined by a core symbiosis between a mycobiont (fungal partner) and a photobiont (photoautotrophic partner), are in fact complex assemblages of microorganisms that constitute a largely untapped source of bioactive secondary metabolites. Historically, compounds isolated from lichens have predominantly been those produced by the dominant fungal partner, and these continue to be of great interest for their unique chemistry and biotechnological potential. In recent years it has become apparent that many photobionts and lichen-associated bacteria also produce a range of potentially valuable molecules. There is evidence to suggest that the unique nature of the symbiosis has played a substantial role in shaping many aspects of lichen chemistry, for example driving bacteria to produce metabolites that do not bring them direct benefit but are useful to the lichen as a whole. This is most evident in studies of cyanobacterial photobionts, which produce compounds that differ from free living cyanobacteria and are unique to symbiotic organisms. The roles that these and other lichen-derived molecules may play in communication and maintaining the symbiosis are poorly understood at present. Nonetheless, advances in genomics, mass spectrometry and other analytical technologies are continuing to illuminate the wealth of biological and chemical diversity present within the lichen holobiome. Implementation of novel biodiscovery strategies such as metagenomic screening, coupled with synthetic biology approaches to reconstitute, re-engineer and heterologously express lichen-derived biosynthetic gene clusters in a cultivable host, offer a promising means for tapping into this hitherto inaccessible wealth of natural products.

  12. Unlocking the potential of orphan legumes.

    Science.gov (United States)

    Cullis, Christopher; Kunert, Karl J

    2017-04-01

    Orphan, or underutilized, legumes are domesticated legumes with useful properties, but with less importance than major world crops due to use and supply constraints. However, they play a significant role in many developing countries, providing food security and nutrition to consumers, as well as income to resource-poor farmers. They have been largely neglected by both researchers and industry due to their limited economic importance in the global market. Orphan legumes are better adapted than the major legume crops to extreme soil and climatic conditions, with high tolerance to abiotic environmental stresses such as drought. As a stress response they can also produce compounds with pharmaceutical value. Orphan legumes are therefore a likely source of important traits for introduction into major crops to aid in combating the stresses associated with global climate change. Modern large-scale genomics techniques are now being applied to many of these previously understudied crops, with the first successes reported in the genomics area. However, greater investment of resources and manpower are necessary if the potential of orphan legumes is to be unlocked and applied in the future. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. The Lotus japonicus ndx gene family is involved in nodule function and maintenance

    DEFF Research Database (Denmark)

    Grønlund, Mette; Gustafsen, Camilla; Jensen, Dorthe Bødker

    2003-01-01

    To elucidate the function of the ndx homeobox genes during the Rhizobium-legume symbiosis, two Lotus japonicus ndr genes were expressed in the antisense orientation under the control of the nodule-expressed promoter Psenod12 in transgenic Lotus japonicus plants. Many of the transformants obtained...... segregated into plants that failed to sustain proper development and maintenance of root nodules concomitant with down-regulation of the two ndx genes. The root nodules were actively fixing nitrogen 3 weeks after inoculation, but the plants exhibited a stunted growth phenotype. The nodules on such antisense...... supplied to the plants in which the two ndx genes are down-regulated. The results presented here, indicate that the ndx genes play a role in the development of structural nodule features, required for proper gas diffusion into the nodule and/or transport of the assimilated nitrogen to the plant....

  14. Mapping the Genetic Basis of Symbiotic Variation in Legume-Rhizobium Interactions in Medicago truncatula

    Science.gov (United States)

    Gorton, Amanda J.; Heath, Katy D.; Pilet-Nayel, Marie-Laure; Baranger, Alain

    2012-01-01

    Mutualisms are known to be genetically variable, where the genotypes differ in the fitness benefits they gain from the interaction. To date, little is known about the loci that underlie such genetic variation in fitness or whether the loci influencing fitness are partner specific, and depend on the genotype of the interaction partner. In the legume-rhizobium mutualism, one set of potential candidate genes that may influence the fitness benefits of the symbiosis are the plant genes involved in the initiation of the signaling pathway between the two partners. Here we performed quantitative trait loci (QTL) mapping in Medicago truncatula in two different rhizobium strain treatments to locate regions of the genome influencing plant traits, assess whether such regions are dependent on the genotype of the rhizobial mutualist (QTL × rhizobium strain), and evaluate the contribution of sequence variation at known symbiosis signaling genes. Two of the symbiotic signaling genes, NFP and DMI3, colocalized with two QTL affecting average fruit weight and leaf number, suggesting that natural variation in nodulation genes may potentially influence plant fitness. In both rhizobium strain treatments, there were QTL that influenced multiple traits, indicative of either tight linkage between loci or pleiotropy, including one QTL with opposing effects on growth and reproduction. There was no evidence for QTL × rhizobium strain or genotype × genotype interactions, suggesting either that such interactions are due to small-effect loci or that more genotype-genotype combinations need to be tested in future mapping studies. PMID:23173081

  15. Specificity traits consistent with legume-rhizobia coevolution displayed by Ensifer meliloti rhizosphere colonization.

    Science.gov (United States)

    Salas, María Eugenia; Lozano, Mauricio Javier; López, José Luis; Draghi, Walter Omar; Serrania, Javier; Torres Tejerizo, Gonzalo Arturo; Albicoro, Francisco Javier; Nilsson, Juliet Fernanda; Pistorio, Mariano; Del Papa, María Florencia; Parisi, Gustavo; Becker, Anke; Lagares, Antonio

    2017-09-01

    Rhizobia are α- and ß-proteobacteria that associate with legumes in symbiosis to fix atmospheric nitrogen. The chemical communication between roots and rhizobia begins in the rhizosphere. Using signature-tagged-Tn5 mutagenesis (STM) we performed a genome-wide screening for Ensifer meliloti genes that participate in colonizing the rhizospheres of alfalfa and other legumes. The analysis of ca. 6,000 mutants indicated that genes relevant for rhizosphere colonization account for nearly 2% of the rhizobial genome and that most (ca. 80%) are chromosomally located, pointing to the relevance and ancestral origin of the bacterial ability to colonize plant roots. The identified genes were related to metabolic functions, transcription, signal transduction, and motility/chemotaxis among other categories; with several ORFs of yet-unknown function. Most remarkably, we identified a subset of genes that impacted more severely the colonization of the roots of alfalfa than of pea. Further analyses using other plant species revealed that such early differential phenotype could be extended to other members of the Trifoliae tribe (Trigonella, Trifolium), but not the Fabeae and Phaseoleae tribes. The results suggest that consolidation of E. meliloti into its current symbiotic state should have occurred in a rhizobacterium that had already been adapted to rhizospheres of the Trifoliae tribe. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

  16. Symbiosis in the microbial world: from ecology to genome evolution

    NARCIS (Netherlands)

    Raina, J.-B.; Eme, L.; Pollock, F.J.; Spang, A.; Archibald, J.M.; Williams, T.A.

    2018-01-01

    The concept of symbiosis – defined in 1879 by de Bary as ‘the living together of unlike organisms’ – has a rich and convoluted history in biology. In part, because it questioned the concept of the individual, symbiosis fell largely outside mainstream science and has traditionally received less

  17. Shoot- and root-borne cytokinin influences arbuscular mycorrhizal symbiosis

    NARCIS (Netherlands)

    Rebeca Cosme, M.P.

    2016-01-01

    The arbuscular mycorrhizal (AM) symbiosis is functionally important for the nutrition and growth of most terrestrial plants. Nearly all phytohormones are employed by plants to regulate the symbiosis with AM fungi, but the regulatory role of cytokinin (CK) is not well understood. Here, we used

  18. Supply chain coordination in industrial symbiosis

    DEFF Research Database (Denmark)

    Herczeg, Gabor; Akkerman, Renzo; Hauschild, Michael Zwicky

    2013-01-01

    Industrial symbiosis (IS) is a form of supply chain cooperation in industrial networks in order to achieve collective benefits by leveraging each other’s by-products and sharing services and utilities. This paper investigates the concept of IS from the perspective of supply chain coordination (SCC......). For this purpose a theoretical framework is built based on SCC aspects, which is subsequently used to analyze a case study. We conclude that research is scant on operational issues and trade-offs as well as on challenges in terms of logistical integration. Also small-scale examples are barely studied or modeled....

  19. Neglecting legumes has compromised human health and sustainable food production.

    Science.gov (United States)

    Foyer, Christine H; Lam, Hon-Ming; Nguyen, Henry T; Siddique, Kadambot H M; Varshney, Rajeev K; Colmer, Timothy D; Cowling, Wallace; Bramley, Helen; Mori, Trevor A; Hodgson, Jonathan M; Cooper, James W; Miller, Anthony J; Kunert, Karl; Vorster, Juan; Cullis, Christopher; Ozga, Jocelyn A; Wahlqvist, Mark L; Liang, Yan; Shou, Huixia; Shi, Kai; Yu, Jingquan; Fodor, Nandor; Kaiser, Brent N; Wong, Fuk-Ling; Valliyodan, Babu; Considine, Michael J

    2016-08-02

    The United Nations declared 2016 as the International Year of Pulses (grain legumes) under the banner 'nutritious seeds for a sustainable future'. A second green revolution is required to ensure food and nutritional security in the face of global climate change. Grain legumes provide an unparalleled solution to this problem because of their inherent capacity for symbiotic atmospheric nitrogen fixation, which provides economically sustainable advantages for farming. In addition, a legume-rich diet has health benefits for humans and livestock alike. However, grain legumes form only a minor part of most current human diets, and legume crops are greatly under-used. Food security and soil fertility could be significantly improved by greater grain legume usage and increased improvement of a range of grain legumes. The current lack of coordinated focus on grain legumes has compromised human health, nutritional security and sustainable food production.

  20. Grain legume protein quality: a hot subject

    Directory of Open Access Journals (Sweden)

    Vaz Patto, Maria Carlota

    2016-06-01

    Full Text Available Grain legumes, also called pulses, play a key role in the nutritional improvement of food and feed. These legumes are important sources of protein as well as other nutritional compounds. Today, protein is one of the most sought after ingredients in the market and grain legumes represent one of the most sustainable protein sources. However, not all grain legume proteins are nutritionally equal. Their quality varies and depends on their amino acid composition and digestibility. In this article, we review concepts related to grain legume protein quality and discuss challenges regarding their genetic improvement. A comprehensive database of grain legume amino acid profiles and protein digestibility is needed to address the matter of protein quality in grain legume breeding. This database will be enhanced by quantitative information on digestibility-reducing bioactive compounds and the development of reliable screening tools. The achievement of higher protein quality grain legume varieties, better adjusted to animal and human requirements, will cut dietary protein content, associated costs and nitrogen excretion, thus reducing the environmental impact.Las leguminosas grano tienen un alto potencial en alimentación humana y animal siendo una importante fuente de proteínas así como de otros compuestos beneficiosos para la nutrición y salud. La proteína es uno de los ingredientes más demandados y las leguminosas grano son una delas fuentes más sostenible de proteína. Sin embargo, no todas las leguminosas grano son igual de nutritivas, variando la calidad con la composición de aminoácidos y su digestibilidad. En este artículo revisaremos los conceptos de calidad de la proteína y discutiremos las posibilidades de mejora genética. Para abordar con éxito la mejora de la calidad de la proteína será de gran ayuda disponer de bases de datos con los perfiles de aminoácidos y de digestibilidad, así como de información cuantitativa sobre los

  1. The Microbiota, Chemical Symbiosis, and Human Disease

    Science.gov (United States)

    Redinbo, Matthew R.

    2014-01-01

    Our understanding of mammalian-microbial mutualism has expanded by combing microbial sequencing with evolving molecular and cellular methods, and unique model systems. Here, the recent literature linking the microbiota to diseases of three of the key mammalian mucosal epithelial compartments – nasal, lung and gastrointestinal (GI) tract – is reviewed with a focus on new knowledge about the taxa, species, proteins and chemistry that promote health and impact progression toward disease. The information presented is further organized by specific diseases now associated with the microbiota:, Staphylococcus aureus infection and rhinosinusitis in the nasal-sinus mucosa; cystic fibrosis (CF), chronic obstructive pulmonary disorder (COPD), and asthma in the pulmonary tissues. For the vast and microbially dynamic GI compartment, several disorders are considered, including obesity, atherosclerosis, Crohn’s disease, ulcerative colitis, drug toxicity, and even autism. Our appreciation of the chemical symbiosis ongoing between human systems and the microbiota continues to grow, and suggest new opportunities for modulating this symbiosis using designed interventions. PMID:25305474

  2. Identification of companion legumes for Midmar Italian ryegrass ...

    African Journals Online (AJOL)

    In a preliminary investigation seven legumes were planted alone and in combination with Lolium multiflorum cv. Midmar. The pure stands of legumes were harvested at either four, five of six week cutting intervals, while the pure stands of Lolium multiflorum and the ryegrass/legume mixtures received in addition to the cutting ...

  3. legume and mineral fertilizer derived nutrient use efficiencies

    African Journals Online (AJOL)

    It aimed at assessing legume-derived nutrient use efficiencies (NUE) by maize and quantifying the importance of these legumes ... replacement indices (N-FRI and P-FRI) by legumes, which express their importance as source of N and P for maize relative to .... associated nutrient stocks were measured at the dry pod stage, ...

  4. Population Genetic Baseline of the First Plataspid Stink Bug Symbiosis (Hemiptera: Heteroptera: Plataspidae Reported in North America

    Directory of Open Access Journals (Sweden)

    Tyler D. Eaton

    2011-06-01

    Full Text Available The stink bug, Megacopta cribraria, has an obligate relationship with a bacterial endosymbiont which allows it to feed on legumes. The insect is a pest of soybeans in Asia and was first reported in the Western Hemisphere in October 2009 on kudzu vine, Pueraria montana, in North Georgia, USA. By October 2010 M. cribraria had been confirmed in 80 counties in Georgia actively feeding on kudzu vine and soybean plants. Since the symbiosis may support the bug’s ecological expansions, a population genetic baseline for the symbiosis was developed from mitochondrial DNA (mtDNA and nuclear DNA (nuDNA gene sequence collected from each insect and its primary g- proteobacterium and secondary a -proteobacterium endosymbionts. A single mitochondrial DNA haplotype was found in all insects sampled in Georgia and South Carolina identified as GA1. The GAI haplotype appears to be rapidly dispersing across Georgia and into contiguous states. Primary and secondary endosymbiont gene sequences from M. cribraria in Georgia were the same as those found in recently collected Megacopta samples from Japan. The implications of these data are discussed.

  5. Soil characteristics under legume and non-legume tree canopies in ...

    African Journals Online (AJOL)

    %, 100% and 150% the distance from tree trunk to canopy edge of leguminous sabiá (Mimosa caesalpiniifolia Benth.) and espinheiro (Machaerium aculeatum Raddi) and non-legume cajueiro (Anacardium occidentale L.) and jaqueira ...

  6. X-ray microanalytical studies of mineral elements in the tripartite symbiosis between lima bean, N2-fixing bacteria and mycorrhizal fungi.

    Science.gov (United States)

    Rodak, Bruna Wurr; Freitas, Douglas Siqueira; Bamberg, Soraya Marx; Carneiro, Marco Aurélio Carbone; Guilherme, Luiz Roberto Guimarães

    2017-01-01

    The symbiosis between legumes, arbuscular mycorrhizal (AM) fungi, and N 2 -fixing bacteria (NFB) provides mutual nutritional gains. However, assessing the nutritional status of the microorganisms is a difficult task. A methodology that could assess this status, in situ, could assist managing these organisms in agriculture. This study used X-ray microanalyses to quantify and locate mineral elements in structures formed in a tripartite symbiosis. Lima bean (Phaseolus lunatus L. Walp) was cultivated in pots under greenhouse conditions, to which we have added AM fungal isolates (Glomus macrocarpum and Acaulospora colombiana) and NFB (Bradyrhizobium japonicum) inocula. Uninoculated control plants were also included. Symbionts were evaluated at the onset of flowering. Quantification of the mineral elements in the symbiotic components was performed using energy dispersive X-ray spectroscopy (EDX) and a scanning electron microscopy (SEM) was used to identify structures. EDX analysis detected 13 elements with the most abundant being N, Ca, and Se, occurring in all tissues, Fe in roots, Ni and Al in epidermis and P and Mo in nodules. Elemental quantification in fungal structures was not possible. The distribution of elements was related to their symbiotic function. X-ray microanalysis can be efficiently applied for nutritional diagnosis in tripartite symbiosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Utilization of summer legumes as bioenergy feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Keri B.; Bauer, Philip J.; Ro, Kyoung S. [United States Department of Agriculture, ARS, Coastal Plains Soil, Water, and Plant Research Center, 2611 W. Lucas St. Florence, SC 29501 (United States)

    2010-12-15

    Sunn hemp (Crotolaria juncea), is a fast growing, high biomass yielding tropical legume that may be a possible southeastern bioenergy crop. When comparing this legume to a commonly grown summer legume - cowpeas (Vigna unguiculata), sunn hemp was superior in biomass yield (kg ha{sup -1}) and subsequent energy yield (GJ ha{sup -1}). In one year of the study after 12 weeks of growth, sunn hemp had 10.7 Mg ha{sup -1} of biomass with an energy content of 19.0 Mg ha{sup -1}. This resulted in an energy yield of 204 GJ ha{sup -1}. The energy content was 6% greater than that of cowpeas. Eventhough sunn hemp had a greater amount of ash, plant mineral concentrations were lower in some cases of minerals (K, Ca, Mg, S) known to reduce thermochemical conversion process efficiency. Pyrolytic degradation of both legumes revealed that sunn hemp began to degrade at higher temperatures as well as release greater amounts of volatile matter at a faster rate. (author)

  8. 7606 IMPROVEMENT OF DIABETIC DYSLIPIDEMIA BY LEGUMES ...

    African Journals Online (AJOL)

    Rotimi

    2013-04-02

    Apr 2, 2013 ... motor and sensory function occurs frequently in diabetes mellitus [19]. This may contribute to decrease in food intake and faecal output as well as eventual loss in weight. The findings from this study indicate that consumption of legume-based diets by diabetic rats resulted in increase in both food intake and ...

  9. Phosphorus Uptake of Three Tropical Legumes

    African Journals Online (AJOL)

    komla

    They were fertilized with South African rock phosphate (EPL 86) and 20 mg of readily soluble phosphate (SP). KH,PO, was also used as starter fertilizer and its effect on utilization of the rock phosphate-P for growth by the legumes was investigated. Shoot dry weight of cowpea was unaffected by mycorrhiza only treatment but ...

  10. LEGUMES UTILISED IN TRADITIONAL FOODS IN IRAQ

    Directory of Open Access Journals (Sweden)

    Dalaram S. Ismael

    2014-02-01

    Full Text Available Iraq is famous in the traditional food from legumes, especially chickpea, lentil, and beans are fresh and dry seeds and as well as for peas, beans and the seeds of faba, cowpea and chickpeas boiled with salt eaten in the form of Lablabe, or make soup from fresh cowpea, fresh faba bean, fresh fasoulia, as well as lentil soup (shorbat adas and different kinds of salad. Turshi, pickled vegetables and fresh pea, fresh fasoulia in the cuisine of many Balkan and Middle East countries. It is a traditional appetizer, meze. Chickpea is eaten on form falafel . The cuisine of Iraq reflects this rich inheritance as well as strong influence from the culinary traditions of neighbouring Persia, Turkey and the Syria region area. Meals begin with appetizers and salads known as Mezza. Some popular dishes include kebab (often marinated with garlic, lemon and spices, then grilled. It can be challenging to help people adjust their diet to meet their nutrient needs and promote weight loss, while at the same time still keeping them satiated. Nutrient rich legumes can be a valuable part of such a diet. They contain soluble fibre and protein and are low glycemic index, all of which may help promote satiety. Legumes are one of the most sustainable sources of protein in the world. Legumes are also significant sources of resistant starch, which is fermented by colonic bacteria to short chain fatty acids.

  11. Fungal and plant gene expression in arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Balestrini, Raffaella; Lanfranco, Luisa

    2006-11-01

    Arbuscular mycorrhizas (AMs) are a unique example of symbiosis between two eukaryotes, soil fungi and plants. This association induces important physiological changes in each partner that lead to reciprocal benefits, mainly in nutrient supply. The symbiosis results from modifications in plant and fungal cell organization caused by specific changes in gene expression. Recently, much effort has gone into studying these gene expression patterns to identify a wider spectrum of genes involved. We aim in this review to describe AM symbiosis in terms of current knowledge on plant and fungal gene expression profiles.

  12. Evolution of Fungal enzymes in the attine ant symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    The attine ant symbiosis is characterized by ancient but varying degrees of diffuse co-evolution between the ants and their fungal cultivars. Domesticated fungi became dependent on vertical transmission by queens and the ant colonies came to rely on their symbiotic fungus for food and thus...... as garden substrate, whereas the more basal genera use leaf litter, insect feces and insect carcasses. We hypothesized that enzyme activity of fungal symbionts has co-evolved with substrate use and we measured enzyme activities of fungus gardens in the field to test this, focusing particularly on plant...... essential for the symbiosis in general, but have contributed specifically to the evolution of the symbiosis....

  13. NPR1 protein regulates pathogenic and symbiotic interactions between Rhizobium and legumes and non-legumes.

    Science.gov (United States)

    Peleg-Grossman, Smadar; Golani, Yael; Kaye, Yuval; Melamed-Book, Naomi; Levine, Alex

    2009-12-21

    Legumes are unique in their ability to establish symbiotic interaction with rhizobacteria from Rhizobium genus, which provide them with available nitrogen. Nodulation factors (NFs) produced by Rhizobium initiate legume root hair deformation and curling that entrap the bacteria, and allow it to grow inside the plant. In contrast, legumes and non-legumes activate defense responses when inoculated with pathogenic bacteria. One major defense pathway is mediated by salicylic acid (SA). SA is sensed and transduced to downstream defense components by a redox-regulated protein called NPR1. We used Arabidopsis mutants in SA defense pathway to test the role of NPR1 in symbiotic interactions. Inoculation of Sinorhizobium meliloti or purified NF on Medicago truncatula or nim1/npr1 A. thaliana mutants induced root hair deformation and transcription of early and late nodulins. Application of S. meliloti or NF on M. truncatula or A. thaliana roots also induced a strong oxidative burst that lasted much longer than in plants inoculated with pathogenic or mutualistic bacteria. Transient overexpression of NPR1 in M. truncatula suppressed root hair curling, while inhibition of NPR1 expression by RNAi accelerated curling. We show that, while NPR1 has a positive effect on pathogen resistance, it has a negative effect on symbiotic interactions, by inhibiting root hair deformation and nodulin expression. Our results also show that basic plant responses to Rhizobium inoculation are conserved in legumes and non-legumes.

  14. NPR1 protein regulates pathogenic and symbiotic interactions between Rhizobium and legumes and non-legumes.

    Directory of Open Access Journals (Sweden)

    Smadar Peleg-Grossman

    Full Text Available BACKGROUND: Legumes are unique in their ability to establish symbiotic interaction with rhizobacteria from Rhizobium genus, which provide them with available nitrogen. Nodulation factors (NFs produced by Rhizobium initiate legume root hair deformation and curling that entrap the bacteria, and allow it to grow inside the plant. In contrast, legumes and non-legumes activate defense responses when inoculated with pathogenic bacteria. One major defense pathway is mediated by salicylic acid (SA. SA is sensed and transduced to downstream defense components by a redox-regulated protein called NPR1. METHODOLOGY/PRINCIPAL FINDINGS: We used Arabidopsis mutants in SA defense pathway to test the role of NPR1 in symbiotic interactions. Inoculation of Sinorhizobium meliloti or purified NF on Medicago truncatula or nim1/npr1 A. thaliana mutants induced root hair deformation and transcription of early and late nodulins. Application of S. meliloti or NF on M. truncatula or A. thaliana roots also induced a strong oxidative burst that lasted much longer than in plants inoculated with pathogenic or mutualistic bacteria. Transient overexpression of NPR1 in M. truncatula suppressed root hair curling, while inhibition of NPR1 expression by RNAi accelerated curling. CONCLUSIONS/SIGNIFICANCE: We show that, while NPR1 has a positive effect on pathogen resistance, it has a negative effect on symbiotic interactions, by inhibiting root hair deformation and nodulin expression. Our results also show that basic plant responses to Rhizobium inoculation are conserved in legumes and non-legumes.

  15. Supply Chain Management in Industrial Symbiosis Networks

    DEFF Research Database (Denmark)

    Herczeg, Gabor

    2016-01-01

    Sustainable supply chain management deals with the design and operation of profitable supply chains that also respect limitations on natural resources, do no harm to the environment, and consider the social systems they operate in. In academic research on sustainable supply chain management...... sustainable production op- erations, and are characterized by a supply chain reconfiguration that uses one company’s wastes or by-products as a raw material for another company, avoiding waste disposal while also reducing material requirements. The re- sulting networks of relationships contribute to regional...... sustainable develop- ment efforts, and emphasize synergistic relations, community, and collabora- tion. This thesis takes an operations and supply chain management perspec- tive on industrial symbiosis networks. More specifically, the thesis elaborates on the collaborative and competitive characteristics...

  16. Layers of Symbiosis - Visualizing the Termite Hindgut Microbial Community

    OpenAIRE

    Leadbetter, Jared

    2007-01-01

    Jared Leadbetter takes us for a nature walk through the diversity of life resident in the termite hindgut - a microenvironment containing 250 different species found nowhere else on Earth. Jared reveals that the symbiosis exhibited by this system is multi-layered and involves not only a relationship between the termite and its gut inhabitants, but also involves a complex web of symbiosis among the gut microbes themselves.

  17. Layers of symbiosis--visualizing the termite hindgut microbial community.

    Science.gov (United States)

    Leadbetter, Jared

    2007-01-01

    Jared Leadbetter takes us for a nature walk through the diversity of life resident in the termite hindgut--a microenvironment containing 250 different species found nowhere else on Earth. Jared reveals that the symbiosis exhibited by this system is multi-layered and involves not only a relationship between the termite and its gut inhabitants, but also involves a complex web of symbiosis among the gut microbes themselves.

  18. Programming good relations - development of the arbuscular mycorrhizal symbiosis

    OpenAIRE

    Reinhardt, Didier

    2007-01-01

    The majority of plants live in symbiotic associations with fungi or bacteria that improve their nutrition. Critical steps in a symbiosis are mutual recognition and subsequently the establishment of an intimate association, which involves the penetration of plant tissues and, in many cases, the invasion of individual host cells by the microbial symbiont. Recent advances revealed that in the arbuscular mycorrhizal symbiosis with soil fungi of the order Glomeromycota, plant-derived signals attra...

  19. Determinant factors of industrial symbiosis: greening Pasir Gudang industrial park

    International Nuclear Information System (INIS)

    Teh, B T; Ho, C S; Chau, L W; Matsuoka, Y; Gomi, K

    2014-01-01

    Green industry has been identified as an important element in attaining greater sustainability. It calls for harmonizing robust economic growth with environment protection. Industries, particularly in developing and transitional nations such as Malaysia, are in need of a reform. Many experts and international organizations suggest the concept of industrial symbiosis. Mainly, there are successful cases of industrial symbiosis practices around the world. However, there are numerous cases of failure too. As industrial symbiosis is an emerging new approach, with a short history of two decades, a lot of researches are generally focused on narrow context and technical details. There is a lack of concerted efforts to look into the drivers and barriers of industrial symbiosis across different cases. This paper aims to examine the factors influencing the development of industrial symbiosis from various countries to supports such networks to evolve in Pasir Gudang. The findings show institution, law and regulation, finance, awareness and capacity building, technology, research and development, information, collaboration, market, geography proximity, environmental issues and industry structure affect the formation of industrial symbiosis

  20. Determinant factors of industrial symbiosis: greening Pasir Gudang industrial park

    Science.gov (United States)

    Teh, B. T.; Ho, C. S.; Matsuoka, Y.; Chau, L. W.; Gomi, K.

    2014-02-01

    Green industry has been identified as an important element in attaining greater sustainability. It calls for harmonizing robust economic growth with environment protection. Industries, particularly in developing and transitional nations such as Malaysia, are in need of a reform. Many experts and international organizations suggest the concept of industrial symbiosis. Mainly, there are successful cases of industrial symbiosis practices around the world. However, there are numerous cases of failure too. As industrial symbiosis is an emerging new approach, with a short history of two decades, a lot of researches are generally focused on narrow context and technical details. There is a lack of concerted efforts to look into the drivers and barriers of industrial symbiosis across different cases. This paper aims to examine the factors influencing the development of industrial symbiosis from various countries to supports such networks to evolve in Pasir Gudang. The findings show institution, law and regulation, finance, awareness and capacity building, technology, research and development, information, collaboration, market, geography proximity, environmental issues and industry structure affect the formation of industrial symbiosis.

  1. The Recent Evolution of a Symbiotic Ion Channel in the Legume Family Altered Ion Conductance and Improved Functionality in Calcium Signaling[C][W

    Science.gov (United States)

    Venkateshwaran, Muthusubramanian; Cosme, Ana; Han, Lu; Banba, Mari; Satyshur, Kenneth A.; Schleiff, Enrico; Parniske, Martin; Imaizumi-Anraku, Haruko; Ané, Jean-Michel

    2012-01-01

    Arbuscular mycorrhiza and the rhizobia-legume symbiosis are two major root endosymbioses that facilitate plant nutrition. In Lotus japonicus, two symbiotic cation channels, CASTOR and POLLUX, are indispensable for the induction of nuclear calcium spiking, one of the earliest plant responses to symbiotic partner recognition. During recent evolution, a single amino acid substitution in DOES NOT MAKE INFECTIONS1 (DMI1), the POLLUX putative ortholog in the closely related Medicago truncatula, rendered the channel solo sufficient for symbiosis; castor, pollux, and castor pollux double mutants of L. japonicus were rescued by DMI1 alone, while both Lj-CASTOR and Lj-POLLUX were required for rescuing a dmi1 mutant of M. truncatula. Experimental replacement of the critical serine by an alanine in the selectivity filter of Lj-POLLUX conferred a symbiotic performance indistinguishable from DMI1. Electrophysiological characterization of DMI1 and Lj-CASTOR (wild-type and mutants) by planar lipid bilayer experiments combined with calcium imaging in Human Embryonic Kidney-293 cells expressing DMI1 (the wild type and mutants) suggest that the serine-to-alanine substitution conferred reduced conductance with a long open state to DMI1 and improved its efficiency in mediating calcium oscillations. We propose that this single amino acid replacement in the selectivity filter made DMI1 solo sufficient for symbiosis, thus explaining the selective advantage of this allele at the mechanistic level. PMID:22706284

  2. The recent evolution of a symbiotic ion channel in the legume family altered ion conductance and improved functionality in calcium signaling.

    Science.gov (United States)

    Venkateshwaran, Muthusubramanian; Cosme, Ana; Han, Lu; Banba, Mari; Satyshur, Kenneth A; Schleiff, Enrico; Parniske, Martin; Imaizumi-Anraku, Haruko; Ané, Jean-Michel

    2012-06-01

    Arbuscular mycorrhiza and the rhizobia-legume symbiosis are two major root endosymbioses that facilitate plant nutrition. In Lotus japonicus, two symbiotic cation channels, CASTOR and POLLUX, are indispensable for the induction of nuclear calcium spiking, one of the earliest plant responses to symbiotic partner recognition. During recent evolution, a single amino acid substitution in DOES NOT MAKE INFECTIONS1 (DMI1), the POLLUX putative ortholog in the closely related Medicago truncatula, rendered the channel solo sufficient for symbiosis; castor, pollux, and castor pollux double mutants of L. japonicus were rescued by DMI1 alone, while both Lj-CASTOR and Lj-POLLUX were required for rescuing a dmi1 mutant of M. truncatula. Experimental replacement of the critical serine by an alanine in the selectivity filter of Lj-POLLUX conferred a symbiotic performance indistinguishable from DMI1. Electrophysiological characterization of DMI1 and Lj-CASTOR (wild-type and mutants) by planar lipid bilayer experiments combined with calcium imaging in Human Embryonic Kidney-293 cells expressing DMI1 (the wild type and mutants) suggest that the serine-to-alanine substitution conferred reduced conductance with a long open state to DMI1 and improved its efficiency in mediating calcium oscillations. We propose that this single amino acid replacement in the selectivity filter made DMI1 solo sufficient for symbiosis, thus explaining the selective advantage of this allele at the mechanistic level.

  3. Academia–Industry Symbiosis in Organic Chemistry

    Science.gov (United States)

    2015-01-01

    Conspectus Collaboration between academia and industry is a growing phenomenon within the chemistry community. These sectors have long held strong ties since academia traditionally trains the future scientists of the corporate world, but the recent drastic decrease of public funding is motivating the academic world to seek more private grants. This concept of industrial “sponsoring” is not new, and in the past, some companies granted substantial amounts of money per annum to various academic institutions in exchange for prime access to all their scientific discoveries and inventions. However, academic and industrial interests were not always aligned, and therefore the investment has become increasingly difficult to justify from industry’s point of view. With fluctuating macroeconomic factors, this type of unrestricted grant has become more rare and has been largely replaced by smaller and more focused partnerships. In our view, forging a partnership with industry can be a golden opportunity for both parties and can represent a true symbiosis. This type of project-specific collaboration is engendered by industry’s desire to access very specific academic expertise that is required for the development of new technologies at the forefront of science. Since financial pressures do not allow companies to spend the time to acquire this expertise and even less to explore fundamental research, partnering with an academic laboratory whose research is related to the problem gives them a viable alternative. From an academic standpoint, it represents the perfect occasion to apply “pure science” research concepts to solve problems that benefit humanity. Moreover, it offers a unique opportunity for students to face challenges from the “real world” at an early stage of their career. Although not every problem in industry can be solved by research developments in academia, we argue that there is significant scientific overlap between these two seemingly disparate

  4. Academia-industry symbiosis in organic chemistry.

    Science.gov (United States)

    Michaudel, Quentin; Ishihara, Yoshihiro; Baran, Phil S

    2015-03-17

    Collaboration between academia and industry is a growing phenomenon within the chemistry community. These sectors have long held strong ties since academia traditionally trains the future scientists of the corporate world, but the recent drastic decrease of public funding is motivating the academic world to seek more private grants. This concept of industrial "sponsoring" is not new, and in the past, some companies granted substantial amounts of money per annum to various academic institutions in exchange for prime access to all their scientific discoveries and inventions. However, academic and industrial interests were not always aligned, and therefore the investment has become increasingly difficult to justify from industry's point of view. With fluctuating macroeconomic factors, this type of unrestricted grant has become more rare and has been largely replaced by smaller and more focused partnerships. In our view, forging a partnership with industry can be a golden opportunity for both parties and can represent a true symbiosis. This type of project-specific collaboration is engendered by industry's desire to access very specific academic expertise that is required for the development of new technologies at the forefront of science. Since financial pressures do not allow companies to spend the time to acquire this expertise and even less to explore fundamental research, partnering with an academic laboratory whose research is related to the problem gives them a viable alternative. From an academic standpoint, it represents the perfect occasion to apply "pure science" research concepts to solve problems that benefit humanity. Moreover, it offers a unique opportunity for students to face challenges from the "real world" at an early stage of their career. Although not every problem in industry can be solved by research developments in academia, we argue that there is significant scientific overlap between these two seemingly disparate groups, thereby presenting an

  5. (A structural assessment of the role of the cell surface carbohydrates of Rhizobium in the Rhizobium/legume symbiosis)

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, R.I.

    1991-01-01

    Research continued on the study of cell surface carbohydrates of Rhizobium. Objectives include: To characterize, at a structural level, the differences between the lipopolysaccharides of a representative number of strains from different Rhizobium species to determine which features of LPS structure are species-specific and might, therefore, be determinants of host specificity. Determine the effect(s) of nod gene induction on the structure of Rhizobium lipopolysaccharides and determine whether synthesis of a modified LPS molecule or a new surface glycoconjugate is initiated by nod gene induction. Develop a non-chemical means for rapidly screening large numbers of bacterial strains in order to determine which glycoconjugate structural features are conserved between strains of the same species. Provide the necessary structural information which, when coupled with developments in the rapidly expanding field of Rhizobium genetics, should lead to a clear understanding of the role of Rhizobium surface glycoconjugates in host/symbiont interactions. Progress is discussed.

  6. Characterization of LysM-receptors and their ligands involved in development and regulation of legume-rhizobium symbiosis

    DEFF Research Database (Denmark)

    Broghammer, Angelique; Krusell, Lene; Blaise, Mickael

    transformed Arabidopsis thaliana or in Nicotiana benthamiana leaves by Agrobacterium mediated transient gene expression. The goal of this project is to give us an understanding of the structural features of the LysM-RLKs that determine the specificity of the interaction between Mesorhizobium loti and Lotus...

  7. Distribution and uses of legume DNA clone resources

    International Nuclear Information System (INIS)

    Young, N.D.

    2001-01-01

    Since 1990, my lab has developed and distributed various DNA clone resources for the legumes. In the first several years, the focus was on members of the tropical genus, Vigna, including the widely cultivated species, mungbean (V. radiata) and cowpea (V. unguiculata). Both of these grain legumes play key roles in agriculture in developing countries of Asia (mungbean) and Africa (cowpea). Moreover, because there is substantial genome conservation among legumes, these genetic resources have also been utilized by a wide range of researchers in other crop species. In 1997, my lab began to focus on the development and distribution of a new generation of DNA clone resources; Bacterial Artificial Chromosomes (BAC). A library of these clones was constructed in soybean (Glycine max) the most important legume species worldwide in terms of economic value. Again, the library has become a valuable resource for the legume research community and has been widely used in studies of legume genomics. (author)

  8. Innovations in agronomy for food legumes. A review

    OpenAIRE

    Siddique, Kadambot; Johansen,; Turner, Neil; Jeuffroy,; Hashem,; Sakar,; Gan,; Alghamdi, Salem

    2012-01-01

    Although there is increasing awareness of the importance of food legumes in human, animal and soil health, adoption of improved production technologies for food legume crops is not proceeding at the same pace as for cereal crops. Over the previous decade, the only food legumes to have shown significant production increases have been chickpea, lentil and faba bean in North America, chickpea in Australia, and faba bean in Europe. In smallholder farming in developing countries, production trends...

  9. Rhizobia and other legume nodule bacteria richness in brazilian Araucaria angustifolia forest Riqueza de rizóbios e de outras bactérias de nódulos de leguminosas em floresta de Araucaria angustifolia

    Directory of Open Access Journals (Sweden)

    Daniel Renato Lammel

    2007-08-01

    Full Text Available The Araucaria Forest is a sub-type of the Atlantic Forest, dominated by Araucaria angustifolia, which is considered an endangered species. The understory has a high diversity of plant species, including several legumes. Many leguminous plants nodulate with rhizobia and fix atmospheric nitrogen, contributing to forest sustainability. This work aimed at bacteria isolation and phenotypic characterization from the root nodules of legumes occurring in Araucaria Forests, at Campos do Jordão State Park, Brazil. Nodule bacteria were isolated in YMA growth media and the obtained colonies were classified according to their growth characteristics (growth rate, color, extra cellular polysaccharide production and pH change of the medium. Data were analyzed by cluster and principal components analysis (PCA. From a total of eleven collected legume species, nine presented nodules, and this is the first report on nodulation of five of these legume species. Two hundred and twelve bacterial strains were isolated from the nodules, whose nodule shapes varied widely and there was a great phenotypic richness among isolates. This richness was found among legume species, individuals of the same species, different nodule shapes and even among isolates of the same nodule. These isolates could be classified into several groups, two up to six according to each legume, most of them different from the used growth standards Rhizobium tropici, Bradyrhizobium elkanii and Burkholderia sp. There is some evidence that these distinct groups may be related to the presence of Burkholderia spp. in the nodules of these legumes.A Floresta de Araucária é um sub-tipo da Mata Atlântica, cujo dossel é dominado por Araucaria angustifolia, uma espécie ameaçada de extinção. O sub-bosque dessa floresta tem alta diversidade, incluindo muitas espécies de leguminosas. Estas plantas podem formar nódulos e fixar nitrogênio atmosférico, contribuindo para a sustentabilidade da floresta

  10. Beans (Phaseolus spp.) - model food legumes

    International Nuclear Information System (INIS)

    Broughton, W.J.; Hemandez, H.; Blair, M.; Beebe, S.; Gepts, P.; Vanderleyden, J.

    2001-01-01

    Globally, 800 million people are malnourished. Heavily subsidised farmers in rich countries produce sufficient surplus food to feed the hungry, but not at a price the poor can afford. Even donating the rich world's surplus to the poor would not solve the problem. Most poor people earn their living from agriculture, so a deluge of free food would destroy their livelihoods. Thus, the only answer to world hunger is to safeguard and improve the productivity of farmers in poor countries. Diets of subsistence level farmers in Africa and Latin America often contain sufficient carbohydrates (through cassava, corn/maize, rice, wheat, etc.), but are poor in proteins. Dietary proteins can take the form of scarce animal products (eggs, milk, meat, etc.), but are usually derived from legumes (plants of the bean and pea family). Legumes are vital in agriculture as they form associations with bacteria that 'fix-nitrogen' from the air. Effectively this amounts to internal fertilisation and is the main reason that legumes are richer in proteins than all other plants. Thousands of legume species exist but more common beans (Phaseolus vulgaris L.) are eaten than any other. In some countries such as Mexico and Brazil, beans are the primary source of protein in human diets. As half the grain legumes consumed worldwide are common beans, they represent the species of choice for the study of grain legume nutrition. Unfortunately, the yields of common beans are low even by the standards of legumes, and the quality of their seed proteins is sub-optimal. Most probably this results from millennia of selection for stable rather than high yield, and as such, is a problem that can be redressed by modem genetic techniques. We have formed an international consortium called 'Phaseomics' to establish the necessary framework of knowledge and materials that will result in disease-resistant, stress-tolerant, high-quality protein and high-yielding beans. Phaseomics will be instrumental in improving

  11. Applying industrial symbiosis to chemical industry: A literature review

    Science.gov (United States)

    Cui, Hua; Liu, Changhao

    2017-08-01

    Chemical industry plays an important role in promoting the development of global economy and human society. However, the negative effects caused by chemical production cannot be ignored, which often leads to serious resource consumption and environmental pollution. It is essential for chemical industry to achieve a sustainable development. Industrial symbiosis is one of the key topics in the field of industrial ecology and circular economy, which has been identified as a creative path leading to sustainability. Based on an extensively searching for literatures on linking industrial symbiosis with chemical industry, this paper aims to review the literatures which involves three aspects: (1) economic and environmental benefits achieved by chemical industry through implementing industrial symbiosis, (2) chemical eco-industrial parks, (3) and safety issues for chemical industry. An outlook is also provided. This paper concludes that: (1) chemical industry can achieve both economic and environmental benefits by implementing industrial symbiosis, (2) establishing eco-industrial parks is essential for chemical industry to implement and improve industrial symbiosis, and (3) there is a close relationship between IS and safety issues of chemical industry.

  12. Ocean acidification alters fish–jellyfish symbiosis

    Science.gov (United States)

    Nagelkerken, Ivan; Pitt, Kylie A.; Rutte, Melchior D.; Geertsma, Robbert C.

    2016-01-01

    Symbiotic relationships are common in nature, and are important for individual fitness and sustaining species populations. Global change is rapidly altering environmental conditions, but, with the exception of coral–microalgae interactions, we know little of how this will affect symbiotic relationships. We here test how the effects of ocean acidification, from rising anthropogenic CO2 emissions, may alter symbiotic interactions between juvenile fish and their jellyfish hosts. Fishes treated with elevated seawater CO2 concentrations, as forecast for the end of the century on a business-as-usual greenhouse gas emission scenario, were negatively affected in their behaviour. The total time that fish (yellowtail scad) spent close to their jellyfish host in a choice arena where they could see and smell their host was approximately three times shorter under future compared with ambient CO2 conditions. Likewise, the mean number of attempts to associate with jellyfish was almost three times lower in CO2-treated compared with control fish, while only 63% (high CO2) versus 86% (control) of all individuals tested initiated an association at all. By contrast, none of three fish species tested were attracted solely to jellyfish olfactory cues under present-day CO2 conditions, suggesting that the altered fish–jellyfish association is not driven by negative effects of ocean acidification on olfaction. Because shelter is not widely available in the open water column and larvae of many (and often commercially important) pelagic species associate with jellyfish for protection against predators, modification of the fish–jellyfish symbiosis might lead to higher mortality and alter species population dynamics, and potentially have flow-on effects for their fisheries. PMID:27358374

  13. Performance of organic grain legumes in Tuscany

    Directory of Open Access Journals (Sweden)

    Valentina Moschini

    2014-03-01

    Full Text Available In 2005-2007 growing season, few varieties of field bean, high protein pea and white lupin were compared in an organic farm of Central Italy (Mugello area, Tuscany, to evaluate their agronomic performance in terms of grain yield, nutritional quality and competitive ability against weeds. The experiment was performed under rain-fed conditions. Furthermore, grain legumes features were compared between two different sowing seasons (autumnal vs late-winter for two years, in order to get information on the best time of sowing of these species, and the stability of yields of different genotypes in those climatic and soil conditions. These legumes could be an alternative protein source to external soybean, a high-risk alimentary source of genetically modified organisms, in the organic livestock sector. The main findings indicate that higher yields in grain and crude protein were obtained with the pea species and in particular with cultivars Hardy (4.0 t/ha grain yield; 626 kg/ha crude protein yield and Classic (3.1 t/ha grain yield; 557 kg/ha crude protein yield; followed by field bean cv. Chiaro di Torre Lama (2.9 t/ha grain yield; 624 kg/ha crude protein yield and cv. Vesuvio (2.5 t/ha grain yield; 549 kg/ha crude protein yield. Furthermore the field bean is interesting for the stability of yield in both years despite climatic conditions rather different. The white lupin has showed the lower yield but the best values of grain quality, with higher values in lupin Multitalia for dry matter, crude protein and ether extract and in lupin Luxe also for crude fibre, respect to the other legumes analysed. Among lupin varieties, lupin Multitalia showed the best yield results for the pedo-climatic conditions of Mugello area (0.9 t/ha lupin Multitalia; 0.2 t/ha lupin Luxe. The total yield of organic grain legumes, in the experimental site, is resulted higher with an autumnal seeding respect to the late-winter seeding (2.8 t/ha vs 1.9 t/ha.

  14. Symbiodinium genomes reveal adaptive evolution of functions related to symbiosis

    KAUST Repository

    Liu, Huanle

    2017-10-06

    Symbiosis between dinoflagellates of the genus Symbiodinium and reef-building corals forms the trophic foundation of the world\\'s coral reef ecosystems. Here we present the first draft genome of Symbiodinium goreaui (Clade C, type C1: 1.03 Gbp), one of the most ubiquitous endosymbionts associated with corals, and an improved draft genome of Symbiodinium kawagutii (Clade F, strain CS-156: 1.05 Gbp), previously sequenced as strain CCMP2468, to further elucidate genomic signatures of this symbiosis. Comparative analysis of four available Symbiodinium genomes against other dinoflagellate genomes led to the identification of 2460 nuclear gene families that show evidence of positive selection, including genes involved in photosynthesis, transmembrane ion transport, synthesis and modification of amino acids and glycoproteins, and stress response. Further, we identified extensive sets of genes for meiosis and response to light stress. These draft genomes provide a foundational resource for advancing our understanding Symbiodinium biology and the coral-algal symbiosis.

  15. Understanding the low occurrence of Symbiosis Industrial in Brazil

    Directory of Open Access Journals (Sweden)

    Iara Tonissi Moroni Cutovoi

    2015-09-01

    Full Text Available This paper contributes to the understanding of the low occurrence of Industrial Symbiosis in Brazil. The importance of public policies in Brazil, the development of public policies is confirmed by the institution of the National Solid Waste Policy (PNRS by Law No. 12,305 / 10. Note that companies seek symbiosis in response to regulatory pressure or to increase the efficiency of resource use, emissions reduction, or wastes. Further the importance of including social, cultural and business approaches in planning synergies between companies. Identifies environmental and cooperation regarding the responsibilities and capabilities of each aspect environmental management. Methodologically the study can be regarded as descriptive and exploratory purposes and in relation to the literature regarding methods. Finally, it will be possible barriers are raised on the relationship to the Industrial Symbiosis practices

  16. Effect of exogenous application of rhizopine on lucerne root nodulation

    African Journals Online (AJOL)

    Rhizopine, 3-0 -methyl scyllo-inosamine was applied to the roots of luceme seedling inoculated with either rhizopine synthesizing Sinorhizobium meliloti strain L530 or the non-rhizopine synthesizing strain Rm 1021 . There was an initial delay in nodule formation. A significant increase in the number of nodules formed in ...

  17. effect of exogenous application of rhizopine on lucerne root nodulation

    African Journals Online (AJOL)

    BSN

    U1111·ersi1y of Adelaide, South Australia. *Corresspondaning author. AB TRACT. Rhizopine, 3-0 -methyl scyllo-inosamine was applied to the roots of luceme seedling inoculated with either rhizopine synthesizing Sinorhizobium meliloti strain L530 or the non-rhizopine synthesizing strain Rm 1021. There was an initial ...

  18. The Effect of Indigenous Root-Nodulating Bacteria on Nodulation ...

    African Journals Online (AJOL)

    This study was initiated to isolate and characterize indigenous rhizobia nodulating faba bean, and evaluate symbiotic characteristics between the crop and the rhizobia in major faba bean producing areas in Tigray highlands. Field crops were also surveyed for nodulation in selected sites of seven (7) faba bean growing ...

  19. effect of exogenous application of rhizopine on lucerne root nodulation

    African Journals Online (AJOL)

    BSN

    Meade, H. M., Long, S. R., Ruvkun, G. B., Brown, S. E., and Ausubel, F. M. (1982). Physical and genetic characterisation of symbiotic and auxotrophic mutants of Rhizobium meliloti induced by transposon Tn5 mutagenesis. Jou ma I of Bacteriology. 149: 114-122. Murphy, P.J., Heycke, N., Banfialvi, Z., Tate, M.E., de Bruijn, ...

  20. Rotation effects of grain and herbaceous legumes on maize yield ...

    African Journals Online (AJOL)

    Crop rotation with legumes and fallow has been known to enhance soil fertility and crop productivity. This prompted an investigation into the effects of some legumes and fallow on some soil chemical properties and yield of maize. The study was conducted in 2001 and 2002 on an Alfisol to determine the effects of crop ...

  1. Assessing socio–economic factors influencing adoption of legume ...

    African Journals Online (AJOL)

    Despite the numerous benefits of legume-based multiple cropping systems in soil fertility management, most smallholder sorghum farmers have not adopted them. The aim of this study was to examine socio-economic factors influencing adoption of legume-based multiple cropping systems among smallholder sorghum ...

  2. Contribution of Legume Rotations to the Nitrogen Requirements of a ...

    African Journals Online (AJOL)

    Industrial fertilizers are expensive for small-scale farmers who, as alternative, rely on legume crops for providing N for a subsequent maize crop. A legume-maize rotational experiment was carried out on a Rhodic Ferralsol at Mlingano Agricultural Research Institute in Muheza, Tanga, Tanzania, to evaluate the effects of ...

  3. Induction of prenylated isoflavonoids and stilbenoids in legumes

    NARCIS (Netherlands)

    Aisyah, S.

    2015-01-01

    The germination of legume seeds in the presence or absence of stress factors was studied with respect to compositional changes in prenylated isoflavonoids and stilbenoids. Different strategies were applied using (i) different types of legume seed, (ii) different stress factors i.e. biotic,

  4. Tree legumes: an underexploited resource in warm-climate silvopastures

    Directory of Open Access Journals (Sweden)

    José Carlos Batista Dubeux Junior

    Full Text Available ABSTRACT Tree legumes are an underexploited resource in warm-climate silvopastures. Perceived benefits of tree legumes include provisioning (browse/mast, timber, fuel, human food, natural medicines, and ornamentals, regulating (C sequestration, greenhouse gas mitigation, soil erosion control and riparian buffers, shade, windbreaks, and habitat for pollinators, supporting (biological N2-fixation, nutrient cycling, soil fertility and soil health, photosynthesis, and primary productivity, and cultural ecosystem services. Tree legumes, however, have not been assessed to the same extent as herbaceous legumes. Once tree legumes are established, they are often more persistent than most herbaceous legumes. There are limitations for extended research with tree legume silvopastures, but extensive research has been done in Africa and Australia and recent efforts have been reported in South America. Economic benefits must be demonstrated to land managers to increase adoption. These benefits are apparent in the research and successes already available, but more long-term research, including the livestock component is necessary. Other factors that reduce adoption include paucity of domesticated germplasm, lag in research/technology, challenges of multipurpose trees and management complexity, challenges to mechanization, dangers of invasive weeds, and social and cultural barriers. In the current scenario of climate change and the need to increase food security, tree legumes are a key component for the sustainable intensification of livestock systems in warm-climate regions.

  5. Glycaemic responses of some legumes in Nigeria using non ...

    African Journals Online (AJOL)

    Background: It is established that legumes generally have a low glycaemic index (GI) which means that they raise blood glucose levels very little. However, the glycaemic responses to normal subjects and the GI of these local legumes are not yet established. Objective: This work determined the postprandial glycaemic ...

  6. Farmers' evaluation of legume cover crops for erosion control in ...

    African Journals Online (AJOL)

    Farmers' evaluation of legume cover crops for erosion control in Gathwariga catchment, Kenya. ... International Journal of Agriculture and Rural Development ... Studies were conducted in Gathwariga catchment, Kenya with the aim of evaluating farmers' perception about the impact of legume cover crops (LCC) on soil ...

  7. Testing forage legume technologies with smallholder dairy farmers ...

    African Journals Online (AJOL)

    Mo

    on-station research, suggest the possibility of incorporating forage legumes in farming systems that could solve feed shortages during the ... This paper presents benefits and constraints identified by farmers as a result of integrating forage legumes in farming systems and lessons ..... stock Research Institute. Vol. 5. pp.10-11.

  8. Systematics, diversity and forage value of indigenous legumes of ...

    African Journals Online (AJOL)

    A map representing the collection intensity for the study area showed that the majority of legumes species were collected in the Fynbos, Savanna and Grassland Biome. It is concluded that indigenous South African legumes are extremely diverse and this denotes the importance of further investigating their forage potential ...

  9. Legumes affect alpine tundra community composition via multiple biotic interactions

    NARCIS (Netherlands)

    Soudzilovskaia, N.A.; Aksenova, A.A.; Makarov, M.I.; Onipchenko, V.G.; Logvinenko, O.A.; Braak, ter C.J.F.; Cornelissen, J.H.C.

    2012-01-01

    The soil engineering function of legumes in natural ecosystems is paramount but associated solely with soil nitrogen (N) subsidies, ignoring concomitant biotic interactions such as competitive or inhibitory effects and exchange between mycorrhizas and rhizobia. We aim to (1) disentangle legume

  10. Nitrogen fertilizer replacement value of legumes with residues ...

    African Journals Online (AJOL)

    Crop rotation with legumes can help reduce the inorganic nitrogen fertilizer need of the following maize as a result of increased nitrogen availability in the soil. The Nitrogen Fertilizer Replacement Value (NFRV) method was used to estimate the nitrogen contribution of grain legumes (soybean, cowpea) and an herbaceous ...

  11. Effect of Intercropping Finger Millet with two Indigenous Legumes at ...

    African Journals Online (AJOL)

    In phase one, an indigenous edible legume (Crotalaria brevidens) and a fodder legume (Trifolium quartinianum) were intercropped with finger millet. Each plot was supplied with three nitrogen fertilizer rates (0, 20, and 40 Kg N/ha) in the form of Urea (46% N) in a completely randomized block design with three replicates.

  12. Crops, Nitrogen, Water: Are Legumes Friend, Foe, or Misunderstood Ally?

    Science.gov (United States)

    Adams, Mark A; Buchmann, Nina; Sprent, Janet; Buckley, Thomas N; Turnbull, Tarryn L

    2018-03-17

    Biological nitrogen fixation (BNF) by crop legumes reduces demand for industrial nitrogen fixation (INF). Nonetheless, rates of BNF in agriculture remain low, with strong negative feedback to BNF from reactive soil nitrogen (N) and drought. We show that breeding for yield has resulted in strong relationships between photosynthesis and leaf N in non-leguminous crops, whereas grain legumes show strong relations between leaf N and water use efficiency (WUE). We contrast these understandings with other studies that draw attention to the water costs of grain legume crops, and their potential for polluting the biosphere with N. We propose that breeding grain legumes for reduced stomatal conductance can increase WUE without compromising production or BNF. Legume crops remain a better bet than relying on INF. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Global Synthesis of Drought Effects on Food Legume Production.

    Science.gov (United States)

    Daryanto, Stefani; Wang, Lixin; Jacinthe, Pierre-André

    2015-01-01

    Food legume crops play important roles in conservation farming systems and contribute to food security in the developing world. However, in many regions of the world, their production has been adversely affected by drought. Although water scarcity is a severe abiotic constraint of legume crops productivity, it remains unclear how the effects of drought co-vary with legume species, soil texture, agroclimatic region, and drought timing. To address these uncertainties, we collected literature data between 1980 and 2014 that reported monoculture legume yield responses to drought under field conditions, and analyzed this data set using meta-analysis techniques. Our results showed that the amount of water reduction was positively related with yield reduction, but the extent of the impact varied with legume species and the phenological state during which drought occurred. Overall, lentil (Lens culinaris), groundnut (Arachis hypogaea), and pigeon pea (Cajanus cajan) were found to experience lower drought-induced yield reduction compared to legumes such as cowpea (Vigna unguiculata) and green gram (Vigna radiate). Yield reduction was generally greater when legumes experienced drought during their reproductive stage compared to during their vegetative stage. Legumes grown in soil with medium texture also exhibited greater yield reduction compared to those planted on soil of either coarse or fine texture. In contrast, regions and their associated climatic factors did not significantly affect legume yield reduction. In the face of changing climate, our study provides useful information for agricultural planning and research directions for development of drought-resistant legume species to improve adaptation and resilience of agricultural systems in the drought-prone regions of the world.

  14. Symbiosis as the way of eukaryotic life: The dependent co ...

    Indian Academy of Sciences (India)

    2014-03-15

    Mar 15, 2014 ... system, instead of being seen as functioning solely to keep microbes out of the body, is also found to develop, in part, in dialogue with .... 1 Even today, this ability of the whole to regulate its parts and to make the parts 'fit' is ..... F 2007 Parasitic inhibition of cell death facilitates symbiosis. Proc. Natl. Acad.

  15. Brain-Based Indices for User System Symbiosis

    NARCIS (Netherlands)

    Erp, J.B.F. van; Veltman, J.A.; Grootjen, M.

    2010-01-01

    The future generation user system interfaces need to be user-centric which goes beyond user-friendly and includes understanding and anticipating user intentions. We introduce the concept of operator models, their role in implementing user-system symbiosis, and the usefulness of brain-based indices

  16. Preliminary studies on mycorrhizal symbiosis in plant conservation ...

    African Journals Online (AJOL)

    ... each orchid species to associate with specific Rhizoctonia isolate and taxonomic trends were observed in the association. The four studies show changes in host plant and soil conditions to greatly determine mycorrhizal symbiosis, species composition and abundance. Journal of Tropical Microbiology Vol.3 2004: 48-62 ...

  17. The vesicular-arbuscular mycorrhizal symbiosis | Quilambo | African ...

    African Journals Online (AJOL)

    The vesicular-arbuscular mycorrhizal symbiosis. Orlando António Quilambo. Abstract. Vesicular-arbuscular mycorrhiza fungi are associated with the majority ot the terrestrial plants. Their function ranges from stress alleviation to bioremediation in soils polluted with heavy metals. However, our knowledge about this ...

  18. Bark Beetle-Fungal Symbiosis: Context Dependency in Complex Associations

    Science.gov (United States)

    Kier D. Klepzig; D.L. Six

    2004-01-01

    Recent thinking in symbiosis research has emphasized a holistic consideration of these complex interactions. Bark beetles and their associated microbes are one group which has previously not been addressed in this manner. We review the study of symbiotic interactions among bark beetles and microbes in light of this thinking. We describe the considerable progress...

  19. Symbiosis in the microbial world: from ecology to genome evolution

    Directory of Open Access Journals (Sweden)

    Jean-Baptiste Raina

    2018-02-01

    Full Text Available The concept of symbiosis – defined in 1879 by de Bary as ‘the living together of unlike organisms’ – has a rich and convoluted history in biology. In part, because it questioned the concept of the individual, symbiosis fell largely outside mainstream science and has traditionally received less attention than other research disciplines. This is gradually changing. In nature organisms do not live in isolation but rather interact with, and are impacted by, diverse beings throughout their life histories. Symbiosis is now recognized as a central driver of evolution across the entire tree of life, including, for example, bacterial endosymbionts that provide insects with vital nutrients and the mitochondria that power our own cells. Symbioses between microbes and their multicellular hosts also underpin the ecological success of some of the most productive ecosystems on the planet, including hydrothermal vents and coral reefs. In November 2017, scientists working in fields spanning the life sciences came together at a Company of Biologists’ workshop to discuss the origin, maintenance, and long-term implications of symbiosis from the complementary perspectives of cell biology, ecology, evolution and genomics, taking into account both model and non-model organisms. Here, we provide a brief synthesis of the fruitful discussions that transpired.

  20. Symbiosis in the microbial world: from ecology to genome evolution.

    Science.gov (United States)

    Raina, Jean-Baptiste; Eme, Laura; Pollock, F Joseph; Spang, Anja; Archibald, John M; Williams, Tom A

    2018-02-22

    The concept of symbiosis - defined in 1879 by de Bary as 'the living together of unlike organisms' - has a rich and convoluted history in biology. In part, because it questioned the concept of the individual, symbiosis fell largely outside mainstream science and has traditionally received less attention than other research disciplines. This is gradually changing. In nature organisms do not live in isolation but rather interact with, and are impacted by, diverse beings throughout their life histories. Symbiosis is now recognized as a central driver of evolution across the entire tree of life, including, for example, bacterial endosymbionts that provide insects with vital nutrients and the mitochondria that power our own cells. Symbioses between microbes and their multicellular hosts also underpin the ecological success of some of the most productive ecosystems on the planet, including hydrothermal vents and coral reefs. In November 2017, scientists working in fields spanning the life sciences came together at a Company of Biologists' workshop to discuss the origin, maintenance, and long-term implications of symbiosis from the complementary perspectives of cell biology, ecology, evolution and genomics, taking into account both model and non-model organisms. Here, we provide a brief synthesis of the fruitful discussions that transpired. © 2018. Published by The Company of Biologists Ltd.

  1. Ectomycorrhizal symbiosis affects functional diversity of rhizosphere fluorescent pseudomonads

    NARCIS (Netherlands)

    Frey-Klett, P.; Chavatte, M.; Clausse, M.L.; Courrier, S.; Roux, Le C.; Raaijmakers, J.M.; Giovanna Martinotti, M.; Pierrat, J.C.; Garbaye, J.

    2005-01-01

    Here we characterized the effect of the ectomycorrhizal symbiosis on the genotypic and functional diversity of soil Pseudomonas fluorescens populations and analysed its possible consequences in terms of plant nutrition, development and health. ¿ Sixty strains of P. fluorescens were isolated from the

  2. Symbiosis of chemometrics and metabolomics: past, present, and future

    NARCIS (Netherlands)

    van der Greef, J.; Smilde, A. K.

    2005-01-01

    Metabolomics is a growing area in the field of systems biology. Metabolomics has already a long history and also the connection of metabolomics with chemometrics goes back some time. This review discusses the symbiosis of metabolomics and chemometrics with emphasis on the medical domain, puts the

  3. The design of industrial symbiosis : an input–output approach

    NARCIS (Netherlands)

    Yazan, Devrim Murat; Yazan, Devrim; Romano, Vincenzo Alessio; Albino, Vito

    2016-01-01

    Industrial symbiosis (IS) has gained more attention in the production economics as the pressure on companies increases for the reduction of waste emissions and primary resources consumption. In fact, this has forced companies to provide other companies their wastes as primary resources and

  4. DUDOC as symbiosis of educational research and educational practice

    NARCIS (Netherlands)

    Goedhart, M.

    2013-01-01

    DUDOC as symbiosis of educational research and educational practice In the DUDOC programme, which started in 2007, nineteen secondary school teachers conducted PhD research projects, supporting the present context-oriented reform of mathematics and science in the higher grades of secondary schools.

  5. Arbuscular mycorrhizal symbiosis-mediated tomato tolerance to drought.

    Science.gov (United States)

    Chitarra, Walter; Maserti, Biancaelena; Gambino, Giorgio; Guerrieri, Emilio; Balestrini, Raffaella

    2016-07-02

    A multidisciplinary approach, involving eco-physiological, morphometric, biochemical and molecular analyses, has been used to study the impact of two different AM fungi, i.e. Funneliformis mosseae and Rhizophagus intraradices, on tomato response to water stress. Overall, results show that AM symbiosis positively affects the tolerance to drought in tomato with a different plant response depending on the involved AM fungal species.

  6. Reciprocal genomic evolution in the ant-fungus agricultural symbiosis

    DEFF Research Database (Denmark)

    Nygaard, Sanne; Hu, Haofu; Li, Cai

    2016-01-01

    The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal...

  7. Ectomycorrhizal symbiosis of tropical African trees.

    Science.gov (United States)

    Bâ, Amadou M; Duponnois, Robin; Moyersoen, Bernard; Diédhiou, Abdala G

    2012-01-01

    The diversity, ecology and function of ectomycorrhizal (EM) fungi and ectomycorrhizas (ECMs) on tropical African tree species are reviewed here. While ECMs are the most frequent mycorrhizal type in temperate and boreal forests, they concern an economically and ecologically important minority of plants in African tropical forests. In these African tropical forests, ECMs are found mainly on caesalpionioid legumes, Sarcolaenaceae, Dipterocarpaceae, Asterpeiaceae, Phyllantaceae, Sapotaceae, Papilionoideae, Gnetaceae and Proteaceae, and distributed in open, gallery and rainforests of the Guineo-Congolian basin, Zambezian Miombo woodlands of East and South-Central Africa and Sudanian savannah woodlands of the sub-sahara. Overall, EM status was confirmed in 93 (26%) among 354 tree species belonging to EM genera. In addition, 195 fungal taxa were identified using morphological descriptions and sequencing of the ML5/ML6 fragment of sporocarps and ECMs from West Africa. Analyses of the belowground EM fungal communities mostly based on fungal internal transcribed spacer sequences of ECMs from Continental Africa, Madagascar and the Seychelles also revealed more than 350 putative species of EM fungi belonging mainly to 18 phylogenetic lineages. As in temperate forests, the /russula-lactarius and /tomentella-thelephora lineages dominated EM fungal flora in tropical Africa. A low level of host preference and dominance of multi-host fungal taxa on different African adult tree species and their seedlings were revealed, suggesting a potential for the formation of common ectomycorrhizal networks. Moreover, the EM inoculum potential in terms of types and density of propagules (spores, sclerotia, EM root fragments and fragments of mycelia strands) in the soil allowed opportunistic root colonisation as well as long-term survival in the soil during the dry season. These are important characteristics when choosing an EM fungus for field application. In this respect, Thelephoroid fungal sp

  8. Energy use in legume cultivation in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Ertekin, C.; Canakci, M.; Yaldiz, O. [Akdeniz Univ., Antalya (Turkey). Faculty of Agriculture, Dept. of Farm Machinery; Kulcu, R. [Suleyman Demirel Univ., Isparta (Turkey). Faculty of Agriculture, Dept. of Farm Machinery

    2010-07-01

    A study was conducted to analyze the energy required to produce different legumes in 11 different regions of Turkey. The objective was to improve energy efficiency. Data was collected for the production of dry bean, chickpea and soybean under rainfed and irrigated conditions, as well as for the production of lentil under rainfed conditions. The data was evaluated in terms of energy use efficiency, energy productivity and specific energy for different regions of Turkey. The main energy sources are human, diesel, fertilizer, seed, machine, chemicals and water. The main agricultural operations are seedbed preparation, seeding, fertilization, hoeing, irrigation, spraying, harvesting, threshing and transporting. The total energy input ranged between 3361.5 and 25229.7 MJ/ha. Based on product yields, the energy use efficiency varied between 0.96 and 4.32.

  9. Legume genetic resources and transcriptome dynamics under abiotic stress conditions.

    Science.gov (United States)

    Abdelrahman, Mostafa; Jogaiah, Sudisha; Burritt, David J; Tran, Lam-Son Phan

    2018-01-04

    Grain legumes are an important source of nutrition and income for billions of consumers and farmers around the world. However, the low productivity of new legume varieties, due to the limited genetic diversity available for legume breeding programmes and poor policymaker support, combined with an increasingly unpredictable global climate is resulting in a large gap between current yields and the increasing demand for legumes as food. Hence, there is a need for novel approaches to develop new high-yielding legume cultivars that are able to cope with a range of environmental stressors. Next-generation technologies are providing the tools that could enable the more rapid and cost-effective genomic and transcriptomic studies for most major crops, allowing the identification of key functional and regulatory genes involved in abiotic stress resistance. In this review, we provide an overview of the recent achievements regarding abiotic stress resistance in a wide range of legume crops and highlight the transcriptomic and miRNA approaches that have been used. In addition, we critically evaluate the availability and importance of legume genetic resources with desirable abiotic stress resistance traits. © 2018 John Wiley & Sons Ltd.

  10. Feed legumes for truly sustainable crop-animal systems

    Directory of Open Access Journals (Sweden)

    Paolo Annicchiarico

    2017-06-01

    Full Text Available Legume cultivation has sharply decreased in Italy during the last 50 years. Lucerne remains widely grown (with about 12% of its area devoted to dehydration, whereas soybean is definitely the most-grown grain legume. Poor legume cropping is mainly due to the gap in yielding ability with major cereals, which has widened up in time according to statistical data. Lucerne displays definitely higher crude protein yield and somewhat lower economic gap with benchmark cereals than feed grain legumes. Pea because of high feed energy production per unit area and rate of genetic progress, and white lupin because of high protein yield per unit area, are particularly interesting for Italian rain-fed environments. Greater legume cultivation in Europe is urged by the need for reducing energy and green-house gas emissions and excessive and unbalanced global N flows through greater symbiotic N fixation and more integrated crop-animal production, as well as to cope with ongoing and perspective raising prices of feed proteins and N fertilisers and insecurity of feed protein supplies. The transition towards greater legume cultivation requires focused research effort, comprehensive stakeholder cooperation and fair economic compensation for legume environmental services, with a key role for genetic improvement dragged by public breeding or pre-breeding. New opportunities for yield improvement arise from the ongoing development of cost-efficient genome-enabled selection procedures, enhanced adaptation to specific cropping conditions via ecophysiological and evolutionary-based approaches, and more thorough exploitation of global genetic resources.

  11. Complete Genome sequence of Burkholderia phymatum STM815, a broad host range and efficient nitrogen-fixing symbiont of Mimosa species

    Energy Technology Data Exchange (ETDEWEB)

    Moulin, Lionel [UMR, France; Klonowska, Agnieszka [UMR, France; Caroline, Bournaud [UMR, France; Booth, Kristina [University of Massachusetts; Vriezen, Jan A.C. [University of Massachusetts; Melkonian, Remy [UMR, France; James, Euan [James Hutton Institute, Dundee, United Kingdom; Young, Peter W. [University of York, United Kingdom; Bena, Gilles [UMR, France; Hauser, Loren John [ORNL; Land, Miriam L [ORNL; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Bruce, David [Los Alamos National Laboratory (LANL); Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Copeland, A [U.S. Department of Energy, Joint Genome Institute; Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Lizotte-Waniewski, Michelle [University of Massachusetts; Bristow, James [U.S. Department of Energy, Joint Genome Institute; Riley, Monica [Woods Hole Oceanographic Institution (WHOI), Woods Hole

    2014-01-01

    Burkholderia phymatum is a soil bacterium able to develop a nitrogen-fixing symbiosis with species of the legume genus Mimosa, and is frequently found associated specifically with Mimosa pudica. The type strain of the species, STM 815T, was isolated from a root nodule in French Guiana in 2000. The strain is an aerobic, motile, non-spore forming, Gram-negative rod, and is a highly competitive strain for nodulation compared to other Mimosa symbionts, as it also nodulates a broad range of other legume genera and species. The 8,676,562 bp genome is composed of two chromosomes (3,479,187 and 2,697,374 bp), a megaplasmid (1,904,893 bp) and a plasmid hosting the symbiotic functions (595,108 bp).

  12. Industrial Symbiosis as a Social Process : Developing theory and methods for the longitudinal investigation of social dynamics in the emergence and development of industrial symbiosis

    NARCIS (Netherlands)

    W. Spekkink (Wouter)

    2016-01-01

    markdownabstractIndustrial symbiosis is a process in which firms in regional industrial systems engage in the exchange of by-products and sharing of utilities and services in order to improve their environmental and economic performance. Industrial symbiosis has a prominent social dimension. To

  13. Agronomic evaluation of herbaceous legumes in a subhumid zone ...

    African Journals Online (AJOL)

    , albeit their introduction into Uganda is recent. Keywords: agronomy; anthracnose; botany; evaluation; forage; herbage; legumes; Namulonge; reseeding; seed yield; Uganda African Journal of Range and Forage Science 1995, 12(2): 68–71 ...

  14. Effect of legume foliage supplementary feeding to dairy cattle offered ...

    African Journals Online (AJOL)

    Pennisetum purpureum) is the main basal diet offered, and is supplemented with legume forages among others. Recent observations indicate reduction in fodder yields of P. purpureum although farmers are applying cattle manure to improve soil fertility ...

  15. [Germinated or fermented legumes: food or ingredients of functional food].

    Science.gov (United States)

    Davila, Marbelly A; Sangronis, Elba; Granito, Marisela

    2003-12-01

    Epidemiological research has shown a positive association between certain diseases and dietary intake of food components found in fruits, grains, legumes, fish oil among others. Food that may provide a health benefit beyond the traditional nutrients that it contains, are named functional food. In addition to the varied nutrients, legumes contain compounds such as polyphenols, soluble fiber, alpha-galactosides and isoflavones which confer propierties of functional foods. Do to the cuse of flatus production in some people, long cooking periods, or anti-nutritional factors, legume consumption levels are limited. In this review, germination and fermentation processes will be presented as alternatives that are able to reduce or inactivate anti-nutritional factors, preserve and even improve the content of the isoflavones, or better the potencial of the legumes as functional food or as ingredients for the formulation of functional foods.

  16. Legume Seed Production Meeting Market Requirements and Economic Impacts

    DEFF Research Database (Denmark)

    Boelt, Birte; Julier, Bernadette; Karagić, Đura

    2015-01-01

    The seed is the carrier of the genetic improvements brought about by modern plant breeding, and seed production is carried out in accordance with certification systems to guarantee consistent high quality. In forage legumes, breeding efforts are primarily related to the vegetative development......-pollinated forage legumes it is further highly influenced by environmental conditions and crop management factors. Further investigations into the use of plant growth regulators and an improved understanding of the interaction between pollinators and the seed crop might improve future seed yields. There is likely...... to be an increasing emphasis on the role of forage legumes in producing high-quality meat and milk, combined with the requirement to reduce the environmental footprint of grassland agriculture. A high forage legume seed yield is a prerequisite to meet market requirements for new, improved cultivars and hence achieve...

  17. Establishment and early persistence of ten forage legumes under ...

    African Journals Online (AJOL)

    Establishment and early persistence of ten forage legumes under three grazing regimes in southern Mozambique. JP Muir. Abstract. Leucaena leucocephala, Clitoria ternatea, Macroptilium atropurpureum cv. Siratro, Cassia rotundifolia cv. Wynn, Macrotyloma axillare cv. Archer, Stylosanthes guianensis var. guianensis cv.

  18. Pasture improvement in Malawi: the introduction of legumes into ...

    African Journals Online (AJOL)

    ; S. guyanensis cv. Schofield, S. humilis cv. Queensland Grown, S. humilis cv. Costal Early, S. humilis (BPI 404) and Lotononis bainessi cv. Miles. Eleven principles of legume introduction into grazing systems are discussed. Keywords: pasture ...

  19. Background and History of the Lotus japonicus Model Legume System

    DEFF Research Database (Denmark)

    Stougaard, Jens

    2014-01-01

    The combination of favourable biological features, stable transformation procedures, application of genetics and genome-based global approaches has established Lotus japonicus as a model legume and provided a platform for addressing important biological questions often, but not exclusively......, focusing on endosymbiosis. Several important discoveries have been made, and the Lotus community has contributed novel results, promoting our understanding of plant biology as well as our understanding of properties and characteristics typical for plants belonging to the legume family. Progress has been...

  20. Growing tropical forage legumes in full sun and silvopastoral systems

    Directory of Open Access Journals (Sweden)

    Saulo Alberto do Carmo Araújo

    2017-02-01

    Full Text Available Growth was evaluated three tropical forage legumes in two cropping systems: silvopastoral system (SSP and full sun. A completely randomized design was adopted in factorial three legumes (estilosanthes cv. Campo Grande (Stylozanthes macrocephala x Stylozanthes capitata, tropical kudzu (Pueraria phaseoloides (Roxb. Benth and macrotiloma (Macrotyloma axillare cv. Java x two farming systems, with 4 repetitions. A eucalyptus SSP already deployed, with spatial arrangement of 12 x 2 m between trees was used. Legumes were planted in January 2014 a uniform cut being made in May 2014. The court assessment was carried out 125 days after the uniformity cut. There was difference for mass production of dry legumes (PMMSL between cultivation systems, evidencing increased productivity in the farming full sun. The macrotiloma showed higher PMSL (5.29 kg DM ha-1 cut-1, while the kudzu obtained the lowest yield (3.42 kg DM ha-1 cut-1 in the sun growing full. The cultivation of legumes in SSP increased the levels of mineral matter, crude protein and neutral detergent fiber. The shade provided by the SSP caused a reduction in the mass of dry matter production, but also altered the chemical composition of the studied legumes.

  1. Oil body biogenesis and biotechnology in legume seeds.

    Science.gov (United States)

    Song, Youhong; Wang, Xin-Ding; Rose, Ray J

    2017-10-01

    The seeds of many legume species including soybean, Pongamia pinnata and the model legume Medicago truncatula store considerable oil, apart from protein, in their cotyledons. However, as a group, legume storage strategies are quite variable and provide opportunities for better understanding of carbon partitioning into different storage products. Legumes with their ability to fix nitrogen can also increase the sustainability of agricultural systems. This review integrates the cell biology, biochemistry and molecular biology of oil body biogenesis before considering biotechnology strategies to enhance oil body biosynthesis. Cellular aspects of packaging triacylglycerol (TAG) into oil bodies are emphasized. Enhancing seed oil content has successfully focused on the up-regulation of the TAG biosynthesis pathways using overexpression of enzymes such as diacylglycerol acyltransferase1 and transcription factors such as WRINKLE1 and LEAFY COTYLEDON1. While these strategies are central, decreasing carbon flow into other storage products and maximizing the packaging of oil bodies into the cytoplasm are other strategies that need further examination. Overall there is much potential for integrating carbon partitioning, up-regulation of fatty acid and TAG synthesis and oil body packaging, for enhancing oil levels. In addition to the potential for integrated strategies to improving oil yields, the capacity to modify fatty acid composition and use of oil bodies as platforms for the production of recombinant proteins in seed of transgenic legumes provide other opportunities for legume biotechnology.

  2. The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis.

    Science.gov (United States)

    Martin, F; Aerts, A; Ahrén, D; Brun, A; Danchin, E G J; Duchaussoy, F; Gibon, J; Kohler, A; Lindquist, E; Pereda, V; Salamov, A; Shapiro, H J; Wuyts, J; Blaudez, D; Buée, M; Brokstein, P; Canbäck, B; Cohen, D; Courty, P E; Coutinho, P M; Delaruelle, C; Detter, J C; Deveau, A; DiFazio, S; Duplessis, S; Fraissinet-Tachet, L; Lucic, E; Frey-Klett, P; Fourrey, C; Feussner, I; Gay, G; Grimwood, J; Hoegger, P J; Jain, P; Kilaru, S; Labbé, J; Lin, Y C; Legué, V; Le Tacon, F; Marmeisse, R; Melayah, D; Montanini, B; Muratet, M; Nehls, U; Niculita-Hirzel, H; Oudot-Le Secq, M P; Peter, M; Quesneville, H; Rajashekar, B; Reich, M; Rouhier, N; Schmutz, J; Yin, T; Chalot, M; Henrissat, B; Kües, U; Lucas, S; Van de Peer, Y; Podila, G K; Polle, A; Pukkila, P J; Richardson, P M; Rouzé, P; Sanders, I R; Stajich, J E; Tunlid, A; Tuskan, G; Grigoriev, I V

    2008-03-06

    Mycorrhizal symbioses--the union of roots and soil fungi--are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants. Boreal, temperate and montane forests all depend on ectomycorrhizae. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains approximately 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features, most notably a battery of effector-type small secreted proteins (SSPs) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific SSPs probably have a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell wall polysaccharides, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem to perform vital functions in the carbon and nitrogen cycles

  3. Establishment of coral-algal symbiosis requires attraction and selection.

    Directory of Open Access Journals (Sweden)

    Hiroshi Yamashita

    Full Text Available Coral reef ecosystems are based on coral-zooxanthellae symbiosis. During the initiation of symbiosis, majority of corals acquire their own zooxanthellae (specifically from the dinoflagellate genus Symbiodinium from surrounding environments. The mechanisms underlying the initial establishment of symbiosis have attracted much interest, and numerous field and laboratory experiments have been conducted to elucidate this establishment. However, it is still unclear whether the host corals selectively or randomly acquire their symbionts from surrounding environments. To address this issue, we initially compared genetic compositions of Symbiodinium within naturally settled about 2-week-old Acropora coral juveniles (recruits and those in the adjacent seawater as the potential symbiont source. We then performed infection tests using several types of Symbiodinium culture strains and apo-symbiotic (does not have Symbiodinium cells yet Acropora coral larvae. Our field observations indicated apparent preference toward specific Symbiodinium genotypes (A1 and D1-4 within the recruits, despite a rich abundance of other Symbiodinium in the environmental population pool. Laboratory experiments were in accordance with this field observation: Symbiodinium strains of type A1 and D1-4 showed higher infection rates for Acropora larvae than other genotype strains, even when supplied at lower cell densities. Subsequent attraction tests revealed that three Symbiodinium strains were attracted toward Acropora larvae, and within them, only A1 and D1-4 strains were acquired by the larvae. Another three strains did not intrinsically approach to the larvae. These findings suggest the initial establishment of corals-Symbiodinium symbiosis is not random, and the infection mechanism appeared to comprise two steps: initial attraction step and subsequent selective uptake by the coral.

  4. Phosphorus and Nitrogen Regulate Arbuscular Mycorrhizal Symbiosis in Petunia hybrida

    OpenAIRE

    Nouri Eva; Breuillin-Sessoms Florence; Feller Urs; Reinhardt Didier

    2014-01-01

    Phosphorus and nitrogen are essential nutrient elements that are needed by plants in large amounts. The arbuscular mycorrhizal symbiosis between plants and soil fungi improves phosphorus and nitrogen acquisition under limiting conditions. On the other hand, these nutrients influence root colonization by mycorrhizal fungi and symbiotic functioning. This represents a feedback mechanism that allows plants to control the fungal symbiont depending on nutrient requirements and supply. Elevated phos...

  5. The genome of Laccaria bicolor provides insights into mycorrhizal symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.; Aerts, A.; Ahren, D.; Brun, A.; Danchin, E. G. J.; Duchaussoy, F.; Gibon, J.; Kohler, A.; Lindquist, E.; Peresa, V.; Salamov, A.; Shapiro, H. J.; Wuyts, J.; Blaudez, D.; Buee, M.; Brokstein, P.; Canback, B.; Cohen, D.; Courty, P. E.; Coutinho, P. M.; Delaruelle, C.; Detter, J. C.; Deveau, A.; DiFazio, S.; Duplessis, S.; Fraissinet-Tachet, L.; Lucic, E.; Frey-Klett, P.; Fourrey, C.; Feussner, I.; Gay, G.; Grimwood, J.; Hoegger, P. J.; Jain, P.; Kilaru, S.; Labbe, J.; Lin, Y. C.; Legue, V.; Le Tacon, F.; Marmeisse, R.; Melayah, D.; Montanini, B.; Muratet, M.; Nehls, U.; Niculita-Hirzel, H.; Secq, M. P. Oudot-Le; Peter, M.; Quesneville, H.; Rajashekar, B.; Reich, M.; Rouhier, N.; Schmutz, J.; Yin, T.; Chalot, M.; Henrissat, B.; Kues, U.; Lucas, S.; Van de Peer, Y.; Podila, G. K.; Polle, A.; Pukkila, P. J.; Richardson, P. M.; Rouze, P.; Sanders, I. R.; Stajich, J. E.; Tunlid, A.; Tuskan, G.; Grigoriev, I. V.

    2007-08-10

    Mycorrhizal symbioses the union of roots and soil fungi are universal in terrestrial ecosystems and may have been fundamental to land colonization by plants 1, 2. Boreal, temperate and montane forests all depend on ectomycorrhizae1. Identification of the primary factors that regulate symbiotic development and metabolic activity will therefore open the door to understanding the role of ectomycorrhizae in plant development and physiology, allowing the full ecological significance of this symbiosis to be explored. Here we report the genome sequence of the ectomycorrhizal basidiomycete Laccaria bicolor (Fig. 1) and highlight gene sets involved in rhizosphere colonization and symbiosis. This 65-megabase genome assembly contains 20,000 predicted protein-encoding genes and a very large number of transposons and repeated sequences. We detected unexpected genomic features, most notably a battery of effector-type small secreted proteins (SSPs) with unknown function, several of which are only expressed in symbiotic tissues. The most highly expressed SSP accumulates in the proliferating hyphae colonizing the host root. The ectomycorrhizae-specific SSPs probably have a decisive role in the establishment of the symbiosis. The unexpected observation that the genome of L. bicolor lacks carbohydrate-active enzymes involved in degradation of plant cell walls, but maintains the ability to degrade non-plant cell wall polysaccharides, reveals the dual saprotrophic and biotrophic lifestyle of the mycorrhizal fungus that enables it to grow within both soil and living plant roots. The predicted gene inventory of the L. bicolor genome, therefore, points to previously unknown mechanisms of symbiosis operating in biotrophic mycorrhizal fungi. The availability of this genome provides an unparalleled opportunity to develop a deeper understanding of the processes by which symbionts interact with plants within their ecosystem to perform vital functions in the carbon and nitrogen cycles that are

  6. Coral Reef Genomics: Developing tools for functional genomics ofcoral symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Schwarz, Jodi; Brokstein, Peter; Manohar, Chitra; Coffroth, MaryAlice; Szmant, Alina; Medina, Monica

    2005-03-01

    Symbioses between cnidarians and dinoflagellates in the genus Symbiodinium are widespread in the marine environment. The importance of this symbiosis to reef-building corals and reef nutrient and carbon cycles is well documented, but little is known about the mechanisms by which the partners establish and regulate the symbiosis. Because the dinoflagellate symbionts live inside the cells of their host coral, the interactions between the partners occur on cellular and molecular levels, as each partner alters the expression of genes and proteins to facilitate the partnership. These interactions can examined using high-throughput techniques that allow thousands of genes to be examined simultaneously. We are developing the groundwork so that we can use DNA microarray profiling to identify genes involved in the Montastraea faveolata and Acropora palmata symbioses. Here we report results from the initial steps in this microarray initiative, that is, the construction of cDNA libraries from 4 of 16 target stages, sequencing of 3450 cDNA clones to generate Expressed Sequenced Tags (ESTs), and annotation of the ESTs to identify candidate genes to include in the microarrays. An understanding of how the coral-dinoflagellate symbiosis is regulated will have implications for atmospheric and ocean sciences, conservation biology, the study and diagnosis of coral bleaching and disease, and comparative studies of animal-protest interactions.

  7. INDUSTRIAL SYMBIOSIS FOR PROMOTING THE GREEN ECONOMY IN ROMANIA

    Directory of Open Access Journals (Sweden)

    FRONE SIMONA

    2017-08-01

    Full Text Available In the efforts to develop a sustainable, low carbon, resource efficient and competitive- ultimately the green economy- in the European Union, the industrial symbiosis is an important conceptual and practical approach with essential contribution. Latest developments in eco-innovation in Romania are those dedicated to implementing the circular economy, as will be analyzed and highlighted in the paper. The main objective of the research is the analysis of the regional eco-innovation potential to play a decisive and major role in the transition to a green economy in Romania, by implementing industrial symbiosis as a high form of circular economy. The methodology is based on previous research outcomes of conceptual and empirical analysis in the areas of sustainable development, resource efficiency, green economy, sustainable forest management, ecoinnovation parks as well as on a case study. The case study will present the main features, including the environmental and economic drivers and benefits of the industrial symbiosis by adding value by recycling wooden waste from logging within the ECOREG pilot eco-industrial park of Suceava County. The conclusions and policy recommendations are that planning, implementing and development of industrial ecosystems is needed in Romania, in view of sustainable regional economic development and a green growth.

  8. Phosphorus and Nitrogen Regulate Arbuscular Mycorrhizal Symbiosis in Petunia hybrida

    Science.gov (United States)

    Nouri, Eva; Breuillin-Sessoms, Florence; Feller, Urs; Reinhardt, Didier

    2014-01-01

    Phosphorus and nitrogen are essential nutrient elements that are needed by plants in large amounts. The arbuscular mycorrhizal symbiosis between plants and soil fungi improves phosphorus and nitrogen acquisition under limiting conditions. On the other hand, these nutrients influence root colonization by mycorrhizal fungi and symbiotic functioning. This represents a feedback mechanism that allows plants to control the fungal symbiont depending on nutrient requirements and supply. Elevated phosphorus supply has previously been shown to exert strong inhibition of arbuscular mycorrhizal development. Here, we address to what extent inhibition by phosphorus is influenced by other nutritional pathways in the interaction between Petunia hybrida and R. irregularis. We show that phosphorus and nitrogen are the major nutritional determinants of the interaction. Interestingly, the symbiosis-promoting effect of nitrogen starvation dominantly overruled the suppressive effect of high phosphorus nutrition onto arbuscular mycorrhiza, suggesting that plants promote the symbiosis as long as they are limited by one of the two major nutrients. Our results also show that in a given pair of symbiotic partners (Petunia hybrida and R. irregularis), the entire range from mutually symbiotic to parasitic can be observed depending on the nutritional conditions. Taken together, these results reveal complex nutritional feedback mechanisms in the control of root colonization by arbuscular mycorrhizal fungi. PMID:24608923

  9. Phosphorus and nitrogen regulate arbuscular mycorrhizal symbiosis in Petunia hybrida.

    Directory of Open Access Journals (Sweden)

    Eva Nouri

    Full Text Available Phosphorus and nitrogen are essential nutrient elements that are needed by plants in large amounts. The arbuscular mycorrhizal symbiosis between plants and soil fungi improves phosphorus and nitrogen acquisition under limiting conditions. On the other hand, these nutrients influence root colonization by mycorrhizal fungi and symbiotic functioning. This represents a feedback mechanism that allows plants to control the fungal symbiont depending on nutrient requirements and supply. Elevated phosphorus supply has previously been shown to exert strong inhibition of arbuscular mycorrhizal development. Here, we address to what extent inhibition by phosphorus is influenced by other nutritional pathways in the interaction between Petunia hybrida and R. irregularis. We show that phosphorus and nitrogen are the major nutritional determinants of the interaction. Interestingly, the symbiosis-promoting effect of nitrogen starvation dominantly overruled the suppressive effect of high phosphorus nutrition onto arbuscular mycorrhiza, suggesting that plants promote the symbiosis as long as they are limited by one of the two major nutrients. Our results also show that in a given pair of symbiotic partners (Petunia hybrida and R. irregularis, the entire range from mutually symbiotic to parasitic can be observed depending on the nutritional conditions. Taken together, these results reveal complex nutritional feedback mechanisms in the control of root colonization by arbuscular mycorrhizal fungi.

  10. Pollen structure and function in caesalpinioid legumes.

    Science.gov (United States)

    Banks, Hannah; Rudall, Paula J

    2016-03-01

    A diverse range of pollen morphologies occurs within the large, paraphyletic legume subfamily Caesalpinioideae, especially among early-branching lineages. Previous studies have hypothesized an association between surface ornamentation and pollination syndrome or other aspects of pollen function such as desiccation tolerance and adaptations to accommodate volume changes. We reviewed caesalpinioid pollen morphology using light microscopy, scanning and transmission electron microscopy, in combination with a literature survey of pollination vectors. Pollen structural diversity is greatest in the early-branching tribes Cercideae and Detarieae, whereas Cassieae and Caesalpinieae are relatively low in pollen diversity. Functional structures to counter desiccation include opercula (lids) covering apertures and reduced aperture size. Structures preventing wall rupture during dehydration and rehydration include different forms of colpi (syncolpi, parasyncolpi, pseudocolpi), striate supratectal ornamentation, and columellate or granular wall structures that resist tensile or compressive forces respectively. Specialized aperture structures (Zwischenkörper) may be advantageous for efficient germination of the pollen tube. In Detarieae and Cercideae in particular, there is potential to utilize pollen characters to estimate pollination systems where these are unknown. Supratectal verrucae and gemmae have apparently evolved iteratively in Cercideae and Detarieae. At the species level, there is a potential correlation between striate/verrucate patterns and vertebrate pollination. © 2016 Botanical Society of America.

  11. Biological Potential of Sixteen Legumes in China

    Directory of Open Access Journals (Sweden)

    Guixing Ren

    2011-10-01

    Full Text Available Phenolic acids have been identified in a variety of legumes including lima bean, broad bean, common bean, pea, jack bean, goa bean, adzuki bean, hyacinth bean, chicking vetch, garbanzo bean, dral, cow bean, rice bean, mung bean and soybean. The present study was carried out with the following aims: (1 to identify and quantify the individual phenolic acid and determine the total phenolic content (TPC; (2 to assess their antioxidant activity, inhibition activities of α-glucosidase, tyrosinase, and formation of advanced glycation endproducts; and (3 to investigate correlations among the phytochemicals and biological activity. Common bean possesses the highest antioxidant activity and advanced glycation endproducts formation inhibition activity. Adzuki bean has the highest α-glucosidase inhibition activity, and mung bean has the highest tyrosinase inhibition activity. There are significant differences in phytochemical content and functional activities among the bean species investigated. Selecting beans can help treat diseases such as dermatological hyperpigmentation illness, type 2 diabetes and associated cardiovascular diseases.

  12. Stringent Expression Control of Pathogenic R-body Production in Legume Symbiont Azorhizobium caulinodans

    Directory of Open Access Journals (Sweden)

    Jun-ichi Matsuoka

    2017-07-01

    Full Text Available R bodies are insoluble large polymers consisting of small proteins encoded by reb genes and are coiled into cylindrical structures in bacterial cells. They were first discovered in Caedibacter species, which are obligate endosymbionts of paramecia. Caedibacter confers a killer trait on the host paramecia. R-body-producing symbionts are released from their host paramecia and kill symbiont-free paramecia after ingestion. The roles of R bodies have not been explained in bacteria other than Caedibacter. Azorhizobium caulinodans ORS571, a microsymbiont of the legume Sesbania rostrata, carries a reb operon containing four reb genes that are regulated by the repressor PraR. Herein, deletion of the praR gene resulted in R-body formation and death of host plant cells. The rebR gene in the reb operon encodes an activator. Three PraR binding sites and a RebR binding site are present in the promoter region of the reb operon. Expression analyses using strains with mutations within the PraR binding site and/or the RebR binding site revealed that PraR and RebR directly control the expression of the reb operon and that PraR dominantly represses reb expression. Furthermore, we found that the reb operon is highly expressed at low temperatures and that 2-oxoglutarate induces the expression of the reb operon by inhibiting PraR binding to the reb promoter. We conclude that R bodies are toxic not only in paramecium symbiosis but also in relationships between other bacteria and eukaryotic cells and that R-body formation is controlled by environmental factors.

  13. Antioxidative ability and membrane integrity in salt-induced responses of Casuarina glauca Sieber ex Spreng. in symbiosis with N2-fixing Frankia Thr or supplemented with mineral nitrogen.

    Science.gov (United States)

    Scotti-Campos, Paula; Duro, Nuno; Costa, Mário da; Pais, Isabel P; Rodrigues, Ana P; Batista-Santos, Paula; Semedo, José N; Leitão, A Eduardo; Lidon, Fernando C; Pawlowski, Katharina; Ramalho, José C; Ribeiro-Barros, Ana I

    2016-06-01

    The actinorhizal tree Casuarina glauca tolerates extreme environmental conditions, such as high salinity. This species is also able to establish a root-nodule symbiosis with N2-fixing bacteria of the genus Frankia. Recent studies have shown that C. glauca tolerance to high salt concentrations is innate and linked to photosynthetic adjustments. In this study we have examined the impact of increasing NaCl concentrations (200, 400 and 600mM) on membrane integrity as well as on the control of oxidative stress in branchlets of symbiotic (NOD+) and non-symbiotic (KNO3+) C. glauca. Membrane selectivity was maintained in both plant groups at 200mM NaCl, accompanied by an increase in the activity of antioxidative enzymes (superoxide dismutase, ascorbate peroxidase, glutathione reductase and catalase). Regarding cellular membrane lipid composition, linolenic acid (C18:3) showed a significant decline at 200mM NaCl in both NOD+ and KNO3+ plants. In addition, total fatty acids (TFA) and C18:2 also decreased in NOD+ plants at this salt concentration, resulting in malondialdehyde (MDA) production. Such initial impact at 200mM NaCl is probably due to the fact that NOD+ plants are subjected to a double stress, i.e., salinity and low nitrogen availability. At 400mM NaCl a strong reduction of TFA and C18:3 levels was observed in both plant groups. This was accompanied by a decrease in the unsaturation degree of membrane lipids in NOD+. However, in both NOD+ and KNO3+ lipid modifications were not reflected by membrane leakage at 200 or 400mM, suggesting acclimation mechanisms at the membrane level. The fact that membrane selectivity was impaired only at 600mM NaCl in both groups of plants points to a high tolerance of C. glauca to salt stress independently of the symbiotic relation with Frankia. Copyright © 2016 Elsevier GmbH. All rights reserved.

  14. Identification of Rhizobium leguminosarum genes and signal compounds involved in the induction of early nodulin gene expression

    NARCIS (Netherlands)

    Scheres, B.J.G.; Wiel, C. van de; Zalensky, A.; Hirsch, A.; Kammen, A. van; Bisseling, T.

    1990-01-01

    The process of root nodule formation on legumes, induced by Rhizobium, can be looked upon as a sequence of several distinct steps. These steps have been defined by cytological studies on developing wild-type root nodules, and by analyses of nodules formed by either plant or bacterial mutants.

  15. Genotypic characterization of indigenous Sinorhizobium meliloti and ...

    African Journals Online (AJOL)

    The rhizobia, Sinorhizobium meliloti and Rhizobium sullae, which fix nitrogen in root nodules of alfalfa (Medicago sativa L.) and sulla (Hedysarum sp.) forage legumes, respectively, were isolated from root nodules and soils from Morocco. We used three PCR-based techniques namely, rep-PCR, RAPD and ARDRA ...

  16. [Development and technological transfer of functional pastas extended with legumes].

    Science.gov (United States)

    Granito, Marisela; Ascanio, Vanesa

    2009-03-01

    Development and technological transfer of functional pastas extended with legumes. Semolina pasta is a highly consumed foodstuff, the biological value of which is low because its protein is deficient in lysine. However, if the semolina is extended with legumes rich in this essential aminoacid, not only and aminoacid supplementation is produced, but also the dietary fibre and minerals are increased. In this work, pastas extended in 10% with a white variety of Phaseolus vulgaris and with Cajanus cajan were produced on a pilot plant scale, and this technology was transferred to a cooperative producing artisanal pastas. The cooking qualities and the physical, chemical, and nutritional characteristics of the pastas were evaluated, as well as the sensorial acceptability in institutionalized elderly people. The extension of the pastas with legume flours increased the optimum cooking time (15 to 20%), the weight (20% and 25%), and the loss of solids by cooking. Similarly, the functional value of the pastas increased by increasing the contents of minerals and dietary fibre. The protein content, as well as the protein digestibility in vitro also increased; however, the parameters of colour L, a and b, and the total starch content of the pastas decreased. At consumer level, the pastas extended with legumes had a good acceptability, for what it was concluded that the extension of the semolina with legume flours in the manufacture of pastas is technologically feasible.

  17. Antisense Repression of the Medicago truncatula Nodule-Enhanced Sucrose Synthase Leads to a Handicapped Nitrogen Fixation Mirrored by Specific Alterations in the Symbiotic Transcriptome and Metabolome1[W

    Science.gov (United States)

    Baier, Markus C.; Barsch, Aiko; Küster, Helge; Hohnjec, Natalija

    2007-01-01

    We analyzed the role of the sucrose (Suc) synthase MtSucS1 during nodulation of the model legume Medicago truncatula, integrating data for the developmental, transcriptional, and metabolic processes affected downstream of an impaired Suc cleavage in root nodules. To reduce carbohydrate supply to nodule tissues, transgenic plants expressing a p35S-driven MtSucS1-antisense fusion were constructed. These plants displayed an up to 90% reduction of MtSucS1 proteins in roots and nodules. Phenotypic studies of two independent MtSucS1-reduced lines demonstrated that only under conditions depending on nodulation, these plants appeared to be impaired in above-ground growth. Specifically plant height, shoot weight, leaf development, flowering, as well as seed maturation were reduced, and the efficiency of photosynthesis was affected. Concomitantly, a significantly enhanced root to shoot ratio with a marked increase in root tip numbers was observed. Root nodule formation was found retarded and the impaired nodulation was accompanied by a less efficient nitrogen (N) acquisition. The decreased total N content of MtSucS1-antisense lines and an enhanced carbon to N ratio in roots, nodules, and shoots correlated with the extent of MtSucS1 knockdown. On the level of transcription, effects of an MtSucS1 reduction were evident for genes representing important nodes of the nodule carbon and N metabolism, while metabolite profiling revealed significantly lower levels of amino acids and their derivatives particularly in strongly MtSucS1-reduced nodules. Our results support the model that nodule-enhanced Suc synthase 1 of the model legume M. truncatula is required for the establishment and maintenance of an efficient N-fixing symbiosis. PMID:17951459

  18. Antisense repression of the Medicago truncatula nodule-enhanced sucrose synthase leads to a handicapped nitrogen fixation mirrored by specific alterations in the symbiotic transcriptome and metabolome.

    Science.gov (United States)

    Baier, Markus C; Barsch, Aiko; Küster, Helge; Hohnjec, Natalija

    2007-12-01

    We analyzed the role of the sucrose (Suc) synthase MtSucS1 during nodulation of the model legume Medicago truncatula, integrating data for the developmental, transcriptional, and metabolic processes affected downstream of an impaired Suc cleavage in root nodules. To reduce carbohydrate supply to nodule tissues, transgenic plants expressing a p35S-driven MtSucS1-antisense fusion were constructed. These plants displayed an up to 90% reduction of MtSucS1 proteins in roots and nodules. Phenotypic studies of two independent MtSucS1-reduced lines demonstrated that only under conditions depending on nodulation, these plants appeared to be impaired in above-ground growth. Specifically plant height, shoot weight, leaf development, flowering, as well as seed maturation were reduced, and the efficiency of photosynthesis was affected. Concomitantly, a significantly enhanced root to shoot ratio with a marked increase in root tip numbers was observed. Root nodule formation was found retarded and the impaired nodulation was accompanied by a less efficient nitrogen (N) acquisition. The decreased total N content of MtSucS1-antisense lines and an enhanced carbon to N ratio in roots, nodules, and shoots correlated with the extent of MtSucS1 knockdown. On the level of transcription, effects of an MtSucS1 reduction were evident for genes representing important nodes of the nodule carbon and N metabolism, while metabolite profiling revealed significantly lower levels of amino acids and their derivatives particularly in strongly MtSucS1-reduced nodules. Our results support the model that nodule-enhanced Suc synthase 1 of the model legume M. truncatula is required for the establishment and maintenance of an efficient N-fixing symbiosis.

  19. Feathermoss and epiphytic Nostoc cooperate differently: expanding the spectrum of plant–cyanobacteria symbiosis

    Energy Technology Data Exchange (ETDEWEB)

    Warshan, Denis; Espinoza, Josh L.; Stuart, Rhona; Richter, Alexander R.; Kim, Sea-Yong; Shapiro, Nicole; Woyke, Tanja; Kyripides, Nikos; Barry, Kerrie W.; Singan, Vasanth; Lindquist, Erika; Ansong, Charles K.; Purvine, Samuel O.; Brewer, Heather M.; Weyman, Philip D.; Dupont, Chris; Rasmussen, Ulla

    2017-12-31

    Dinitrogen (N2)-fixation by cyanobacteria in symbiosis with feather mosses represents the main pathway of biological N input into boreal forests. Despite its significance, little is known about the gene repertoire needed for the establishment and maintenance of the symbiosis. To determine gene acquisitions or regulatory rewiring allowing cyanobacteria to form this symbiosis, we compared closely related Nostoc strains that were either symbiosis-competent or non-competent, using a proteogenomics approach and a unique experimental setup allowing for controlled chemical and physical contact between partners. Thirty-two protein families were only in the genomes of competent strains, including some never before associated with symbiosis. We identified conserved orthologs that were differentially expressed in competent strains, including gene families involved in chemotaxis and motility, NO regulation, sulfate/phosphate transport, sugar metabolism, and glycosyl-modifying and oxidative stress-mediating exoenzymes. In contrast to other cyanobacteria-plant symbioses, the moss-cyanobacteria epiphytic symbiosis is distinct, with the symbiont retaining motility and chemotaxis, and not modulating N-fixation, photosynthesis, GS-GOGAT cycle, and heterocyst formation. Our work expands our knowledge of plant cyanobacterial symbioses, provides an interaction model of this ecologically significant symbiosis, and suggests new currencies, namely nitric oxide and aliphatic sulfonates, may be involved in establishing and maintaining this symbiosis.

  20. The symbiosis between Rhizobium leguminosarum and Pisum sativum : regulation of the nitrogenase activity

    NARCIS (Netherlands)

    Appels, M.A.

    1989-01-01

    Bacteria of the genus Rhizobium can form a symbiosis with plants of the family Leguminosae. Both bacteria and plant show considerable biochemical and morphological changes in order to develop and carry out the symbiosis. The Rhizobia

  1. Impediment to Symbiosis Establishment between Giant Clams and Symbiodinium Algae Due to Sterilization of Seawater

    Science.gov (United States)

    Kurihara, Takeo; Yamada, Hideaki; Inoue, Ken; Iwai, Kenji; Hatta, Masayuki

    2013-01-01

    To survive the juvenile stage, giant clam juveniles need to establish a symbiotic relationship with the microalgae Symbiodinium occurring in the environment. The percentage of giant clam juveniles succeeding in symbiosis establishment (“symbiosis rate”) is often low, which is problematic for seed producers. We investigated how and why symbiosis rates vary, depending on whether giant clam seeds are continuously reared in UV treated or non treated seawater. Results repeatedly demonstrated that symbiosis rates were lower for UV treated seawater than for non treated seawater. Symbiosis rates were also lower for autoclaved seawater and 0.2-µm filtered seawater than for non treated seawater. The decreased symbiosis rates in various sterilized seawater suggest the possibility that some factors helping symbiosis establishment in natural seawater are weakened owing to sterilization. The possible factors include vitality of giant clam seeds, since additional experiments revealed that survival rates of seeds reared alone without Symbiodinium were lower in sterilized seawater than in non treated seawater. In conclusion, UV treatment of seawater was found to lead to decreased symbiosis rates, which is due possibly to some adverse effects common to the various sterilization techniques and relates to the vitality of the giant clam seeds. PMID:23613802

  2. Arbuscular Mycorrhizal Symbiosis Alleviates Diesel Toxicity on Melilotus albus

    International Nuclear Information System (INIS)

    Hernandez-Ortega, H. A.; Alarcon, A.; Ferrera-Cerrato, R.; Zavaleta-Mancera, H. A.

    2009-01-01

    Petroleum hydrocarbons (PH) affect plant growth and development by limiting water absorption and nutrient availability. Arbuscular mycorrhizal fungi (AMF) have been demonstrated to increase plant tolerance of grass species to PH, but the performance of AMF on legume species during phytorremediation of PH-contaminated soils has been scarcely understood. Thus, this research evaluated the effects of AMF on tolerance and growth of Melilotus albus in a diesel-contaminated soil. (Author)

  3. Nitrogen contributions of legume roots to cabbage nutrition

    Directory of Open Access Journals (Sweden)

    Thiago de Oliveira Vargas

    2013-12-01

    Full Text Available The effects of roots are generally not considered in studies assessing crop responses to green manure. However, measuring such effects can contribute to a better understanding of crop rotation. In two experiments, we evaluated the content of legume-N in crop tissue and the fertilizer value of the roots and shoots of two legume species. Roots, shoots, or whole plants of the legumes sunhemp (Crotalaria juncea and jack beans (Canavalia ensiformis were cropped as green manure to supply nitrogen to cabbage crops (Brassica oleracea var. capitata. The principle of the A-value technique was applied to estimate the fertilizer value of each plant part. In a pot experiment, both the content of legume-N in cabbage and the fertilizer value of the whole plant was higher than the shoots, which was in turn higher than that of the roots. In field condition, roots had a decreasing effect on the N content of cabbage plants. Growing cabbage on legume root residue resulted in an increased absorption of 15N-urea, resulting in negative values ​​for legume-N content: -13.59 g kg-1 and -3.51 g kg-1 for sunhemp and jack beans, respectively. Suggesting both low N supply by roots and N immobilization in soil organic matter or microbial biomass. Future research should focus on estimating the net N acquisition by plants from root residues under field conditions, where rooting patterns and biomass distribution differ from those in pot experiments, therefore giving a more realistic quantitative estimate.

  4. Nitrogen transfer from forage legumes to nine neighbouring plants in a multi-species grassland

    DEFF Research Database (Denmark)

    Pirhofer-Walzl, Karin; Rasmussen, Jim; Jensen, Henning Høgh

    2012-01-01

    amounts of N from legumes than dicotyledonous plants which generally have taproots. Slurry application mainly increased N transfer from legumes to grasses. During the growing season the three legumes transferred approximately 40 kg N ha-1 to neighbouring plants. Below-ground N transfer from legumes...... to neighbouring plants differed among nitrogen donors and nitrogen receivers and may depend on root characteristics and regrowth strategies of plant species in the multi-species grassland.......Legumes play a crucial role in nitrogen supply to grass-legume mixtures for ruminant fodder. To quantify N transfer from legumes to neighbouring plants in multi-species grasslands we established a grass-legume-herb mixture on a loamy-sandy site in Denmark. White clover (Trifolium repens L.), red...

  5. Stellar Pulsations and Stellar Evolution: Conflict, Cohabitation, or Symbiosis?

    Science.gov (United States)

    Weiss, Achim

    While the analysis of stellar pulsations allows the determination of current properties of a star, stellar evolution models connect it with its previous history. In many cases results from both methods do not agree. In this review some classical and current cases of disagreement are presented. In some cases these conflicts led to an improvement of the theory of stellar evolution, while in others they still remain unsolved. Some well-known problems of stellar physics are pointed out as well, for which it is hoped that seismology—or in general the analysis of stellar pulsations—will help to resolve them. The limits of this symbiosis will be discussed as well.

  6. Helical computed tomography and the workstation: introduction to a symbiosis

    International Nuclear Information System (INIS)

    Garcia-Santos, J.M.

    1997-01-01

    We do a brief introduction to the possibilities of an helical computed tomography system when it is associated with a powerful workstation. The fast and volumetric way of acquisition constitutes, basically, the main advantage of this sort of computed tomography. The anatomical and radio pathological study, in a workstation, of the acquired information (thanks to multiplanar and 3D reconstruction), increases significantly our capacity of analysis in each patient. Only the clinical and radiological experience will tell us which is the right place that this symbiosis occupies within our diagnosis tools. (Author) 11 refs

  7. Sustainable agriculture: possible trajectories from mutualistic symbiosis and plant neodomestication.

    Science.gov (United States)

    Duhamel, Marie; Vandenkoornhuyse, Philippe

    2013-11-01

    Food demand will increase concomitantly with human population. Food production therefore needs to be high enough and, at the same time, minimize damage to the environment. This equation cannot be solved with current strategies. Based on recent findings, new trajectories for agriculture and plant breeding which take into account the belowground compartment and evolution of mutualistic strategy, are proposed in this opinion article. In this context, we argue that plant breeders have the opportunity to make use of native arbuscular mycorrhizal (AM) symbiosis in an innovative ecologically intensive agriculture. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Effects of alternative legume seeds on Barbaresca lamb meat quality

    Directory of Open Access Journals (Sweden)

    P. Pennisi

    2011-03-01

    Full Text Available In recent years a renewed interest towards the use of local legume seeds in animal nutrition was raising in Mediterranean areas. Conventional feedstuffs such as maize and soybean and animal by-products, the former widely diffused as genetically modified organisms (GMO and the latter related to “mad cow disease” produced significative changes in public perceptions, justifying a dramatic increase of the use of alternative protein and energy sources such as legume seeds (peas, faba beans, chickpeas (Hanbury et al., 2000...

  9. Optimization of cereal-legume blend ratio to enhance the nutritional ...

    African Journals Online (AJOL)

    This study investigated the effect of different cereal-legume blending ratios on nutritional quality and functional property of different blends. The legumes and steeped cereals were cleaned, minimally roasted, dehulled, milled and sifted separately. A single-factor experiment with three levels of the factor (cereal: legume ratio ...

  10. rotational effects of grain legumes on maize performance in the rift

    African Journals Online (AJOL)

    2000-10-27

    Oct 27, 2000 ... The study has demonstrated that the use of grain legumes, particularly dolichos in rotation with maize, is a ... legume plant residues (Onim etal., 1990; Kwesiga and Coe, 1994; Wortmann et al., 1994; Peoples et ... It may be feasible to produce suitably adapted legumes during the shcrt rains to produce ...

  11. Improving the environmental performance of biofuels with industrial symbiosis

    International Nuclear Information System (INIS)

    Martin, Michael; Eklund, Mats

    2011-01-01

    In the production of biofuels for transport many critics have argued about the poor energy efficiency and environmental performance of the production industries. Optimism is thus set on the production of second generation biofuels, while first generation biofuels continue to dominate worldwide. Therefore it is interesting to consider how the environmental performance of first generation biofuel industries can be improved. The field of industrial symbiosis offers many possibilities for potential improvements in the biofuel industry and theories from this research field are used in this paper to highlight how environmental performance improvements can be accomplished. This comes in the form of by-product synergies and utility synergies which can improve material and energy handling. Furthermore, the processes and products can gain increased environmental performance improvements by the adaption of a renewable energy system which will act as a utility provider for many industries in a symbiotic network. By-products may thereafter be upcycled through biogas production processes to generate both energy and a bio-fertilizer. A case study of an actual biofuel industrial symbiosis is also reviewed to provide support for these theories. -- Highlights: → By-product and utility synergies may improve the production processes of biofuel industries for reduced energy consumption and improved environmental performance. → Upcycling tenants can make use of wastes to upgrade waste to a valuable product and/or energy source. → Energy systems for biofuel production have a large influence on the performance of biofuel industries.

  12. Shared metabolic pathways in a coevolved insect-bacterial symbiosis.

    Science.gov (United States)

    Russell, Calum W; Bouvaine, Sophie; Newell, Peter D; Douglas, Angela E

    2013-10-01

    The symbiotic bacterium Buchnera aphidicola lacks key genes in the biosynthesis of five essential amino acids (EAAs), and yet its animal hosts (aphids) depend on the symbiosis for the synthesis of these EAAs (isoleucine, leucine, methionine, phenylalanine, and valine). We tested the hypothesis, derived from genome annotation, that the missing Buchnera reactions are mediated by host enzymes, with the exchange of metabolic intermediates between the partners. The specialized host cells bearing Buchnera were separated into a Buchnera fraction and a Buchnera-free host cell fraction (HF). Addition of HF to isolated Buchnera preparations significantly increased the production of leucine and phenylalanine, and recombinant enzymes mediating the final reactions in branched-chain amino acid and phenylalanine synthesis rescued the production of these EAAs by Buchnera preparations without HF. The likely precursors for the missing proximal reactions in isoleucine and methionine synthesis were identified, and they differed from predictions based on genome annotations: synthesis of 2-oxobutanoate, the aphid-derived precursor of isoleucine synthesis, was stimulated by homoserine and not threonine via threonine dehydratase, and production of the homocysteine precursor of methionine was driven by cystathionine, not cysteine, via reversal of the transsulfuration pathway. The evolution of shared metabolic pathways in this symbiosis can be attributed to host compensation for genomic deterioration in the symbiont, involving changes in host gene expression networks to recruit specific enzymes to the host cell.

  13. Value of the Hydra model system for studying symbiosis.

    Science.gov (United States)

    Kovacevic, Goran

    2012-01-01

    Green Hydra is used as a classical example for explaining symbiosis in schools as well as an excellent research model. Indeed the cosmopolitan green Hydra (Hydra viridissima) provides a potent experimental framework to investigate the symbiotic relationships between a complex eumetazoan organism and a unicellular photoautotrophic green algae named Chlorella. Chlorella populates a single somatic cell type, the gastrodermal myoepithelial cells (also named digestive cells) and the oocyte at the time of sexual reproduction. This symbiotic relationship is stable, well-determined and provides biological advantages to the algal symbionts, but also to green Hydra over the related non-symbiotic Hydra i.e. brown hydra. These advantages likely result from the bidirectional flow of metabolites between the host and the symbiont. Moreover genetic flow through horizontal gene transfer might also participate in the establishment of these selective advantages. However, these relationships between the host and the symbionts may be more complex. Thus, Jolley and Smith showed that the reproductive rate of the algae increases dramatically outside of Hydra cells, although this endosymbiont isolation is debated. Recently it became possible to keep different species of endosymbionts isolated from green Hydra in stable and permanent cultures and compare them to free-living Chlorella species. Future studies testing metabolic relationships and genetic flow should help elucidate the mechanisms that support the maintenance of symbiosis in a eumetazoan species.

  14. Role of quorum sensing in Sinorhizobium meliloti-Alfalfa symbiosis.

    Science.gov (United States)

    Gurich, Nataliya; González, Juan E

    2009-07-01

    The ExpR/Sin quorum-sensing system of the gram-negative soil bacterium Sinorhizobium meliloti plays an important role in the establishment of symbiosis with its host plant Medicago sativa. A mutant unable to produce autoinducer signal molecules (sinI) is deficient in its ability to invade the host, but paradoxically, a strain lacking the quorum-sensing transcriptional regulator ExpR is as efficient as the wild type. We compared the whole-genome expression profile of the wild-type strain with strains missing one of the quorum-sensing regulatory components to identify genes controlled by the ExpR/Sin system throughout the different phases of the bacterial growth cycle, as well as in planta. Our analyses revealed that ExpR is a highly versatile regulator with a unique ability to show different regulatory capabilities in the presence or absence of an autoinducer. In addition, this study provided us with insight into the plant invasion defect displayed by the autoinducer mutant. We also discovered that the ExpR/Sin quorum-sensing system is repressed after plant invasion. Therefore, quorum sensing plays a crucial role in the regulation of many cell functions that ensures the successful invasion of the host and is inactivated once symbiosis is established.

  15. A sea slug’s guide to plastid symbiosis

    Directory of Open Access Journals (Sweden)

    Jan de Vries

    2014-12-01

    Full Text Available Some 140 years ago sea slugs that contained chlorophyll-pigmented granules similar to those of plants were described. While we now understand that these “green granules” are plastids the slugs sequester from siphonaceous algae upon which they feed, surprisingly little is really known about the molecular details that underlie this one of a kind animal-plastid symbiosis. Kleptoplasts are stored in the cytosol of epithelial cells that form the slug’s digestive tubules, and one would guess that the stolen organelles are acquired for their ability to fix carbon, but studies have never really been able to prove that. We also do not know how the organelles are distinguished from the remaining food particles the slugs incorporate with their meal and that include algal mitochondria and nuclei. We know that the ability to store kleptoplasts long-term has evolved only a few times independently among hundreds of sacoglossan species, but we have no idea on what basis. Here we take a closer look at the history of sacoglossan research and discuss recent developments. We argue that, in order to understand what makes this symbiosis work, we will need to focus on the animal’s physiology just as much as we need to commence a detailed analysis of the plastids’ photobiology. Understanding kleptoplasty in sacoglossan slugs requires an unbiased multidisciplinary approach.

  16. Understanding resilience in industrial symbiosis networks: insights from network analysis.

    Science.gov (United States)

    Chopra, Shauhrat S; Khanna, Vikas

    2014-08-01

    Industrial symbiotic networks are based on the principles of ecological systems where waste equals food, to develop synergistic networks. For example, industrial symbiosis (IS) at Kalundborg, Denmark, creates an exchange network of waste, water, and energy among companies based on contractual dependency. Since most of the industrial symbiotic networks are based on ad-hoc opportunities rather than strategic planning, gaining insight into disruptive scenarios is pivotal for understanding the balance of resilience and sustainability and developing heuristics for designing resilient IS networks. The present work focuses on understanding resilience as an emergent property of an IS network via a network-based approach with application to the Kalundborg Industrial Symbiosis (KIS). Results from network metrics and simulated disruptive scenarios reveal Asnaes power plant as the most critical node in the system. We also observe a decrease in the vulnerability of nodes and reduction in single points of failure in the system, suggesting an increase in the overall resilience of the KIS system from 1960 to 2010. Based on our findings, we recommend design strategies, such as increasing diversity, redundancy, and multi-functionality to ensure flexibility and plasticity, to develop resilient and sustainable industrial symbiotic networks. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Emergence and seedling growth of five forage legume species at ...

    African Journals Online (AJOL)

    Jane

    2011-08-17

    Aug 17, 2011 ... Seed characteristics of legume species used in this study. Species. Cultivar. Collect location. Seed mass (mg). T. repens. -. Jilin Province. 0.58±0.002 .... The effects of depth (D), light (L), species (S) and their interaction on germination characteristics, morphological ..... Early seedling growth of pine (Pinus.

  18. Advances in genetics and molecular breeding of three legume crops ...

    Indian Academy of Sciences (India)

    2012-10-15

    Oct 15, 2012 ... for crop improvement. Progress in the development of genomic ... genetic maps and genomic resources will certainly accelerate crop improvement programmes in the SAT legumes. http://www.ias.ac.in/jbiosci ..... and oil quality at UAS-D, while genotyping with 53 poly- morphic markers was generated at ...

  19. Assessment of Traditionally Produced Dakuwa (A Cereal/Legume ...

    African Journals Online (AJOL)

    Dakuwa (a local legume/cereal snack) samples were collected from local producers cutting across seven local government areas in Niger State, central Nigeria and assessed on the basis of proximate composition, anti-nutritional factors and mineral content, microbiological and sensory qualities. There were significant ...

  20. Progress with the legume bacteria in Rhodesia | HDL | African ...

    African Journals Online (AJOL)

    Progress during eight years of work in Rhodesia with Rhizobium is presented. 370 of the country's 507 known indigenous species of legumes have been examined for nodulation, and all but 13 found to form nodules. A collection of 573 isolates of Rhizobium, 221 of them from other countries, has been built up on a basis of ...

  1. Emergence and seedling growth of five forage legume species at ...

    African Journals Online (AJOL)

    A field study compared the seedling emergence and structure of five forage legumes (Trifolium repens L., Medicago falcata L., Melilotus suaveolens Ledeb, Medicago sativa L. and Lespedeza davurica Schindler) at five planting depths (1, 2, 4, 6 and 8 cm) and two light levels (full light and shade) on the 21st day after ...

  2. Productivity and stability of various grass-legume mixtures with ...

    African Journals Online (AJOL)

    Three trials were established at Cedara under dryland conditions to determine the production, persistence and value of Trifolium repens cv. Ladino, Trifolium pratense cv. Kenland red and Desmodium uncinatum cv. Silverleaf. These legumes were row-planted into Pennisetum clandestinum (kikuyu); Cynodon nlemfuensis ...

  3. Assessment of some macromineral concentration of a grass/ legume ...

    African Journals Online (AJOL)

    The assessment of macromineral concentration of Panicum/Stylosanthes mixtures was carried out at the Cattle Production Venture, Federal University of Agriculture, Abeokuta, in Southwest Nigeria. The study aimed to determine the concentration of some macromineral elements in the grass/legume pasture grazed by the ...

  4. Manipulating legume/cereal mixtures to optimize the above and ...

    African Journals Online (AJOL)

    The purpose of mixing legume and cereals in the cropping systems is to optimise the use of spatial, temporal, and physical resources both above- and below ground, by maximising positive interactions (facilitation) and minimising negative ones (competition) among the components. The complex interactions in ...

  5. Qualitative nutrient requirements of selected legume species on two ...

    African Journals Online (AJOL)

    Three perennial legumes (Macroptilium atropurpureum, Rhynchosia totta and Rhynchosia minima) were evaluated in a glass-house under uncontrolled environmental conditions for herbage, root and nodule yield on two soils and on river sand under six fertilizer treatments. Keywords: qualitative analyses|nutrient ...

  6. Perennial legumes on dry lands in the western Highveld region ...

    African Journals Online (AJOL)

    There exists a great need for perennial pasture legumes which are adapted to dryland production in the western Highveld. ... Averaged over two years, three selections yielded more than two tonnes dry material per ha: namely, Desmodium uncinatum 2,78, Medicago sativa 2,74 and Macroptilium atropurpureum 2,10.

  7. Advances in genetics and molecular breeding of three legume crops ...

    Indian Academy of Sciences (India)

    2012-10-15

    Oct 15, 2012 ... genetic maps and genomic resources will certainly accelerate crop improvement programmes in the SAT legumes. http://www.ias.ac.in/jbiosci ... soil plant analytical development; SSR, simple sequence repeats; TAC, transcript assembly contig; TE, transpiration efficiency; TUS, tentative unique sequences.

  8. evaluation of nutrient composition of some cereals and legumes

    African Journals Online (AJOL)

    USER

    was found to be highest in N(1.10kg-1) and P(0.0597) than other legumes residues. Other essential nutrients like calcium, magnesium and potassium were also determined. Generally, crop residues and their ashes are ... to the integrated application of organic and inorganic fertilizer in tropical crop production. Despite the.

  9. Advances in genetics and molecular breeding of three legume crops ...

    Indian Academy of Sciences (India)

    Molecular markers are the most powerful genomic tools to increase the efficiency and precision of breeding practices for crop improvement. Progress in the development of genomic resources in the leading legume crops of the semi-arid tropics (SAT), namely, chickpea (Cicer arietinum), pigeonpea (Cajanus cajan) and ...

  10. Ensilage of tropical grasses mixed with legumes and molasses.

    Science.gov (United States)

    Tjandraatmadja, M; Norton, B W; Mac Rae, I C

    1994-01-01

    The effects of adding two legumes, Gliricidia sepium and Leucaena leucocephala, cv. Cunningham, and molasses on the fermentation characteristics of silages made from two tropical grasses (Pangola grass, Digitaria decumbens, and Setaria sphacelata cv. Kazungula) were investigated. Pangola grass silages contained significantly higher contents of water-soluble carbohydrates and lactic acid than did setaria silages after 100 days fermentation, but there were no significant differences between the two silages in populations of lactic acid bacteria and contents of total N and NH3-N. Addition of either species of legume had no significant effect on fermentation acids and NH3-N contents, and numbers of lactic acid bacteria. Addition of both legumes reduced NH3-N production in the silages by 59% after 5 days' fermentation. Numbers of lactic acid bacteria were not significantly affected by the different treatments. Enterococcus faecalis represented 60% of the lactic acid bacteria isolated from the treated herbages prior to ensiling. By 100 days of fermentation, only lactobacilli were isolated: 82% homo-fermenters and 18% hetero-fermenters. Lactobacillus mesenteroides subsp. dextranicum was found only in the silage supplemented with 33% (w/w) legume. It was concluded that the low quality of tropical grasses used as feeds for ruminants may be significantly improved by ensiling these grasses with small amounts of molasses and with high-protein tree leaves.

  11. Symbiotic specificity of tropical tree rhizobia for host legumes

    NARCIS (Netherlands)

    Bala, A.; Giller, K.E.

    2001-01-01

    The host range and specificity is reported of a genetically diverse group of rhizobia isolated from nodules of Calliandra calothyrsus, Gliricidia sepium, Leucaena leucocephala and Sesbania sesban. Nodule number and nitrogen content was measured in seedlings of herbaceous and woody legume species

  12. Effects of interplanted legumes with maize on major soil nutrients ...

    African Journals Online (AJOL)

    A field experiment was carried out at the Teaching and Research Farm of the University of Ibadan, in early 2004 and 2005 to evaluate the effects of interplanted legumes with maize on major soil nutrients and performance of maize. The experiment laid out in a randomized complete block design, with four levels of crop ...

  13. Uses of tree legumes in semi-arid regions

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.

    1980-01-01

    Uses of tree legumes in semi-arid and arid regions are reviewed. This review is divided into sections according to the following general use categories: fuels; human food; livestock food; to increase yields of crops grown beneath their canopies;and control of desertification. (MHR)

  14. Phenolic Profiles and Antioxidant Activity of Germinated Legumes

    Directory of Open Access Journals (Sweden)

    Do Tan Khang

    2016-04-01

    Full Text Available Bioactive compounds, which are naturally produced in plants, have been concerned with the food and pharmaceutical industries because of the pharmacological effects on humans. In this study, the individual phenolics of six legumes during germination and antioxidant capacity from sprout extracts were determined. It was found that the phenolic content significantly increased during germination in all legumes. Peanuts showed the strongest antioxidant capacity in both the DPPH• (1,1-diphenyl-2-picrylhydrazyl method and the reducing power assay (32.51% and 84.48%, respectively. A total of 13 phenolic acids were detected and quantified. There were 11 phenolic constituents identified in adzuki beans; 10 in soybeans; 9 in black beans, mung beans, and white cowpeas; and 7 compounds in peanuts. Sinapic acid and cinnamic acid were detected in all six legume sprouts, and their quantities in germinated peanuts were the highest (247.9 µg·g−1 and 62.9 µg·g−1, respectively. The study reveals that, among the investigated legumes, germinated peanuts and soybeans obtained maximum phenolics and antioxidant capacity.

  15. Predicting the Chemical composition of herbaceous legumes using ...

    African Journals Online (AJOL)

    Predicting the Chemical composition of herbaceous legumes using Near Infrared Reflectance Spectroscopy. J F Mupangwa, N Berardo, N T Ngongoni, J H Topps, H Hamudikuwanda, M Ordoardi. Abstract. (Journal of Applied Science in Southern Africa: 2000 6(2): 107-114). http://dx.doi.org/10.4314/jassa.v6i2.16844.

  16. Evaluation of nutrient composition of some cereals and legumes ...

    African Journals Online (AJOL)

    The use of compost for horticultural crops production in Nigeria is beginning to gain some attention, since it has been reported to improve plant growth and yield. Some cereals and legumes crops residues with potentials of being used as compost materials such as Sorghum Stovers, Rice Straws, Maize Stovers, Millet ...

  17. Role of symbiotic nitrogen fixation in the improvement of legume ...

    African Journals Online (AJOL)

    Role of symbiotic nitrogen fixation in the improvement of legume productivity under stressed environments. R Serraj, J Adu-Gyamfi. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/wajae.v6i1.45613.

  18. Annual legumes for improving soil fertility in the smallholder maize ...

    African Journals Online (AJOL)

    We need to screen new legumes for local adaptation to see if there are new species or accessions that do better on smallholder farms. Some green manures, especially ... More work with velvet beans is required on farms to establish the size and speed of yield gains for following maize crops. Also, more participatory work ...

  19. Legume and mineral fertilizer derived nutrient use efficiencies by ...

    African Journals Online (AJOL)

    Experimentations included eight treatments in a RCB design (n=3): four herbaceous legume-maize successions and four continuous maize cropping with urea (U, 46% N, 50 kg ha-1), triple superphosphate (TSP, 45% P, 30 kg ha-1), urea+triple superphosphate (U+TSP) and a control. The NUE was estimated through ...

  20. Adoption of fodder legumes technology through farmer-to-farmer ...

    African Journals Online (AJOL)

    Mo

    Adoption of fodder legumes technology through farmer-to-farmer extension approach. J. Sinja,ab*J. Karugia,b M. Waithakaac, D. Miano,c I. Baltenwecka; S. Franzeld ... informal methods of dissemination especially farmer-to-farmer extension. It is not known ... Results showed that farmers with positions in farmer groups, with.

  1. LEGUMES IN SOIL FERTILITY MANAGEMENT: THE CASE OF ...

    African Journals Online (AJOL)

    02001, African Crop Science Society. LEGUMES IN SOIL FERTILITY MANAGEMENT: THE CASE OF PIGEONPEA. IN SMALLHOLDER FARMING SYSTEMS OF ZIMBABWE. - P. MAPFUMO, B.M. CAMPBELL1, S. MPEPEREKI and P. MAFONGOYA2. Department of Soil Sclence and Agricultural Engineering, University of ...

  2. Relative efficiency of legumes in utilizing soil and fertilizer phosphorus

    International Nuclear Information System (INIS)

    Joshi, O.P.; Prasad, R.; Subbiah, B.V.

    1977-01-01

    A pot-culture study was made at Indian Agricultural Research Institute, New Delhi to study the native P feeding power of six rainy season legumes (green gram, black gram, cowpea, pigeon pea, soyabean and groundnut). Ordinary superphosphate tagged with 32 P was used in the study. At the first harvest (30 days after seeding) soybean and cowpea and at the second harvest (45 days after sowing) cowpea and groundnut removed more P than the other legumes. Pigeon pea removed the least P due to its slow growth. The tracer studies showed that during the first 30 days, groundnut, pigeon pea and soyabean were relatively better feeders of native soil P than the other legumes. Some varietal differences with respect to their capacity to feed on native soil P were also observed and in groundnut the varieties AK-12-24 and Jyoti removed more soil P than the variety NG-268. Differences between the legumes with respect to feeding on native soil P were much less at the second harvest (45 days after seeding). (author)

  3. Profitability of sorghum-legume cropping practices among ...

    African Journals Online (AJOL)

    Mo

    kilogram. Besides that, groundnut and sorghum-legume intercrops incurred the highest variable costs which could have negatively affected their gross margins. Corresponding gross margins from the different enterprises were generated as shown in table 2. Analysis of variance on the Gross margin of sorghum-cowpea ...

  4. Improvement of diabetic dyslipidemia by legumes in experimental rats

    African Journals Online (AJOL)

    Grain legumes are a valuable source of food proteins; hence, their exploitation is expected to grow in relation to a growing world's food needs. Apart from high level of dietary fibre, their protein composition makes them useful in managing diabetes. This paper reports a study conducted to evaluate the effects of four different ...

  5. Antinutritional effects of legume seeds in piglets, rats and chickens

    NARCIS (Netherlands)

    Huisman, J.

    1990-01-01

    There is a growing interest in Europe to be self-supporting with regard to the protein supply for animal diets. Peas and beans growing well under European climatic conditions could provide alternatives to soya. However, these legume seeds contain the same classes of antinutritional factors

  6. Evaluation of concentrate, grass and legume combinations on ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-10-16

    Oct 16, 2006 ... reduction in dietary protein intake of rabbits in the latter stages of growth where rabbits are raised up to 2.5-2.8 kg live weight. This study was designed therefore to evaluate the utilization of combinations of concentrate, grass and legume forages on performance and nutrient digestibility of grower rabbits.

  7. Enzymatic hydrolysis: a method in alleviating legume allergenicity.

    Science.gov (United States)

    Kasera, Ramkrashan; Singh, A B; Lavasa, S; Prasad, Komarla Nagendra; Arora, Naveen

    2015-02-01

    Legumes are involved in IgE mediated food allergy in many countries. Avoidance of allergenic food is the only way to avoid symptomatic reaction. The present study investigated the effect of enzymatic hydrolysis on the allergenicity of three legumes - kidney bean (Phaseolus vulgaris), black gram (Vigna mungo) and peanut (Arachis hypogaea). Soluble protein extracts of the study legumes were sequentially treated by Alcalase(®) and Flavourzyme(®). Allergenicity of hydrolysates was then determined by ELISA, immunoblot, stripped basophil histamine release and skin prick test (SPT). Hydrolysis resulted in the loss of all IgE binding fractions determined by immunoblot in the three legumes. Specific IgE binding in ELISA was reduced by 62.2 ± 7.7%, 87.1 ± 9.6% and 91.8 ± 7.2% in the hydrolysates of kidney bean, black gram and peanut, respectively (p < 0.01). The release of histamine was decreased significantly when sensitized basophils were challenged with hydrolysates as compared to raw extracts. Significant reduction in the biopotency of hydrolysates was also observed in SPT where only 1/10 kidney bean-sensitive individuals, 2/6 black gram-sensitive individuals and 1/7 peanut-sensitive individuals were found positive to their respective hydrolysates. In conclusion, enzymatic hydrolysis is effective in attenuating allergenicity of legume proteins and may be employed for preparing hypoallergenic food extracts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Traits affecting early season nitrogen uptake in nine legume species

    Directory of Open Access Journals (Sweden)

    Elana Dayoub

    2017-02-01

    Full Text Available Legume crops are known to have low soil N uptake early in their life cycle, which can weaken their ability to compete with other species, such as weeds or other crops in intercropping systems. However, there is limited knowledge on the main traits involved in soil N uptake during early growth and for a range of species. The objective of this research was to identify the main traits explaining the variability among legume species in soil N uptake and to study the effect of the soil mineral N supply on the legume strategy for the use of available N sources during early growth. Nine legume species were grown in rhizotrons with or without N supply. Root expansion, shoot and root biomass, nodule establishment, N2 fixation and mineral soil N uptake were measured. A large interspecific variability was observed for all traits affecting soil N uptake. Root lateral expansion and early biomass in relation to seed mass were the major traits influencing soil N uptake regardless of the level of soil N availability. Fenugreek, lentil, alfalfa, and common vetch could be considered weak competitors for soil N due to their low plant biomass and low lateral root expansion. Conversely, peanut, pea, chickpea and soybean had a greater soil N uptake. Faba bean was separated from other species having a higher nodule biomass, a higher N2 fixation and a lower seed reserve depletion. Faba bean was able to simultaneously fix N2 and take up soil N. This work has identified traits of seed mass, shoot and root biomass, root lateral expansion, N2 fixation and seed reserve depletion that allowing classification of legume species regarding their soil N uptake ability during early growth.

  9. Traits affecting early season nitrogen uptake in nine legume species.

    Science.gov (United States)

    Dayoub, Elana; Naudin, Christophe; Piva, Guillaume; Shirtliffe, Steven J; Fustec, Joëlle; Corre-Hellou, Guénaëlle

    2017-02-01

    Legume crops are known to have low soil N uptake early in their life cycle, which can weaken their ability to compete with other species, such as weeds or other crops in intercropping systems. However, there is limited knowledge on the main traits involved in soil N uptake during early growth and for a range of species. The objective of this research was to identify the main traits explaining the variability among legume species in soil N uptake and to study the effect of the soil mineral N supply on the legume strategy for the use of available N sources during early growth. Nine legume species were grown in rhizotrons with or without N supply. Root expansion, shoot and root biomass, nodule establishment, N 2 fixation and mineral soil N uptake were measured. A large interspecific variability was observed for all traits affecting soil N uptake. Root lateral expansion and early biomass in relation to seed mass were the major traits influencing soil N uptake regardless of the level of soil N availability. Fenugreek, lentil, alfalfa, and common vetch could be considered weak competitors for soil N due to their low plant biomass and low lateral root expansion. Conversely, peanut, pea, chickpea and soybean had a greater soil N uptake. Faba bean was separated from other species having a higher nodule biomass, a higher N 2 fixation and a lower seed reserve depletion. Faba bean was able to simultaneously fix N 2 and take up soil N. This work has identified traits of seed mass, shoot and root biomass, root lateral expansion, N 2 fixation and seed reserve depletion that allowing classification of legume species regarding their soil N uptake ability during early growth.

  10. Contribution of legumes to the soil N pool.

    Science.gov (United States)

    Fustec, Joëlle; Malagoli, Philippe; Mahieu, Stéphanie

    2010-05-01

    Grain legumes can be used for nitrogen acquisition in different ways in sustainable agriculture (Fustec et al., 2009). They are seen as a tool to reduce mineral N fertilizers in cropping systems. However, estimates of biological N fixation, N balance and N benefit either for the following crop or in mixed crops, remain unclear. The contribution of legumes to the soil N pool is difficult to measure, especially N rhizodeposition, since it is a critical point for assessing N benefits for other crops and for soil biological activity, and for reducing water pollution (Mayer et al., 2003). We adapted and refined the cotton-wick 15N stem labeling method for measuring the amount of soil N derived from rhizodeposition by field peas (Mahieu et al., 2007, 2009). The method was tested in different conditions in the field and in the greenhouse with various pea varieties and isolines. In addition, we used the cotton-wick method for assessing N transfers from pea to neighbouring durum wheat. In the greenhouse, a positive relationship was found between the amount of N rhizodeposits and the legume N content. N rhizodeposition was about 15% of the plant N and 30% in the field. In field pea / durum wheat intercrops, plant-plant N transfers were quantified and found to be bidirectional. Such results should be taken into account when estimating N benefits from biological N fixation by a grain legume crop and for the prediction of N economies in legume-based cropping systems. More studies dealing with rhizodeposit compounds and soil biological activity would now be necessary. Fustec et al. 2009. Agron. Sustain. Dev., DOI 10.1051/agro/2009003, in press. Mahieu et al. 2007. Plant Soil 295, 193-205. Mahieu et al. 2009. Soil Biol. Biochem. 41, 2236-2243. Mayer et al. 2003. Soil Biol. Biochem. 35, 21-28.

  11. Legumes in Finnish agriculture: history, present status and future prospects

    Directory of Open Access Journals (Sweden)

    F. L. STODDARD

    2008-12-01

    Full Text Available Legumes are important in world agriculture, providing biologically fixed nitrogen, breaking cereal disease cycles and contributing locally grown food and feed, including forage. Pea and faba bean were grown by early farmers in Finland, with remains dated to 500 BC. Landraces of pea and faba bean were gradually replaced by better adapted, higher quality materials for food use. While grain legumes have been restricted by their long growing seasons to the south of the country, red, white and alsike clovers are native throughout and have long been used in leys for grazing, hay and silage. Breeding programmes released many cultivars of these crops during the 1900s, particularly pea and red clover. A.I. Virtanen earned the 1945 Nobel Prize in Chemistry for his work on both nitrogen fixation and silage preservation. Use of crop mixtures may appear modern, but farmers used them already in the early 1800s, when oat was used to support pea, and much effort has been devoted to improving the system and establishing its other benefits. Although international cultivars have been easily accessible since Finland’s 1995 entry into the European Union, the combination of feed quality and appropriate earliness is still needed, as < 1% of arable land is sown to grain legumes and an increase to 9–10% would allow replacement of imported protein feeds. Climate change will alter the stresses on legume crops, and investment in agronomy, physiology and breeding is needed so that farmers can gain from the many advantages of a legume-supported rotation.;

  12. Fast induction of biosynthetic polysaccharide genes lpxA, lpxE, and rkpI of Rhizobium sp. strain PRF 81 by common bean seed exudates is indicative of a key role in symbiosis.

    Science.gov (United States)

    Oliveira, Luciana Ruano; Rodrigues, Elisete Pains; Marcelino-Guimarães, Francismar Corrêa; Oliveira, André Luiz Martinez; Hungria, Mariangela

    2013-06-01

    Rhizobial surface polysaccharides (SPS) are, together with nodulation (Nod) factors, recognized as key molecules for establishment of rhizobia-legume symbiosis. In Rhizobium tropici, an important nitrogen-fixing symbiont of common bean (Phaseolus vulgaris L.), molecular structures and symbiotic roles of the SPS are poorly understood. In this study, Rhizobium sp. strain PRF 81 genes, belonging to the R. tropici group, were investigated: lpxA and lpxE, involved in biosynthesis and modification of the lipid-A anchor of lipopolysaccharide (LPS), and rkpI, involved in synthesis of a lipid carrier required for production of capsular polysaccharides (KPS). Reverse transcription quantitative PCR (RT-qPCR) analysis revealed, for the first time, that inducers released from common bean seeds strongly stimulated expression of all three SPS genes. When PRF 81 cells were grown for 48 h in the presence of seed exudates, twofold increases (p Rhizobium radiobacter and were more related to R. etli and Rhizobium leguminosarum, while rkpI was closer to the Sinorhizobium sp. group. Upregulation of lpxE, lpxA, and rkpI genes suggests that seed exudates can modulate production of SPS of Rhizobium sp. PRF81, leading to cell wall changes necessary for symbiosis establishment.

  13. A Comparative Nitrogen Balance and Productivity Analysis of Legume and Non-legume Supported Cropping Systems: The Potential Role of Biological Nitrogen Fixation

    DEFF Research Database (Denmark)

    Iannetta, Pietro P M; Young, Mark; Bachinger, Johann

    2016-01-01

    The potential of biological nitrogen fixation (BNF) to provide sufficient N for production has encouraged re-appraisal of cropping systems that deploy legumes. It has been argued that legume-derived N can maintain productivity as an alternative to the application of mineral fertilizer, although few...... studies have systematically evaluated the effect of optimizing the balance between legumes and non N-fixing crops to optimize production. In addition, the shortage, or even absence in some regions, of measurements of BNF in crops and forages severely limits the ability to design and evaluate new legume...

  14. SymRK defines a common genetic basis for plant root endosymbioses with arbuscular mycorrhiza fungi, rhizobia, and Frankiabacteria.

    Science.gov (United States)

    Gherbi, Hassen; Markmann, Katharina; Svistoonoff, Sergio; Estevan, Joan; Autran, Daphné; Giczey, Gabor; Auguy, Florence; Péret, Benjamin; Laplaze, Laurent; Franche, Claudine; Parniske, Martin; Bogusz, Didier

    2008-03-25

    Root endosymbioses vitally contribute to plant nutrition and fitness worldwide. Nitrogen-fixing root nodulation, confined to four plant orders, encompasses two distinct types of associations, the interaction of legumes (Fabales) with rhizobia bacteria and actinorhizal symbioses, where the bacterial symbionts are actinomycetes of the genus Frankia. Although several genetic components of the host-symbiont interaction have been identified in legumes, the genetic basis of actinorhiza formation is unknown. Here, we show that the receptor-like kinase gene SymRK, which is required for nodulation in legumes, is also necessary for actinorhiza formation in the tree Casuarina glauca. This indicates that both types of nodulation symbiosis share genetic components. Like several other legume genes involved in the interaction with rhizobia, SymRK is also required for the interaction with arbuscular mycorrhiza (AM) fungi. We show that SymRK is involved in AM formation in C. glauca as well and can restore both nodulation and AM symbioses in a Lotus japonicus symrk mutant. Taken together, our results demonstrate that SymRK functions as a vital component of the genetic basis for both plant-fungal and plant-bacterial endosymbioses and is conserved between legumes and actinorhiza-forming Fagales.

  15. The symbiotic biofilm of Sinorhizobium fredii SMH12, necessary for successful colonization and symbiosis of Glycine max cv Osumi, is regulated by Quorum Sensing systems and inducing flavonoids via NodD1.

    Directory of Open Access Journals (Sweden)

    Francisco Pérez-Montaño

    Full Text Available Bacterial surface components, especially exopolysaccharides, in combination with bacterial Quorum Sensing signals are crucial for the formation of biofilms in most species studied so far. Biofilm formation allows soil bacteria to colonize their surrounding habitat and survive common environmental stresses such as desiccation and nutrient limitation. This mode of life is often essential for survival in bacteria of the genera Mesorhizobium, Sinorhizobium, Bradyrhizobium, and Rhizobium. The role of biofilm formation in symbiosis has been investigated in detail for Sinorhizobium meliloti and Bradyrhizobium japonicum. However, for S. fredii this process has not been studied. In this work we have demonstrated that biofilm formation is crucial for an optimal root colonization and symbiosis between S. fredii SMH12 and Glycine max cv Osumi. In this bacterium, nod-gene inducing flavonoids and the NodD1 protein are required for the transition of the biofilm structure from monolayer to microcolony. Quorum Sensing systems are also required for the full development of both types of biofilms. In fact, both the nodD1 mutant and the lactonase strain (the lactonase enzyme prevents AHL accumulation are defective in soybean root colonization. The impairment of the lactonase strain in its colonization ability leads to a decrease in the symbiotic parameters. Interestingly, NodD1 together with flavonoids activates certain quorum sensing systems implicit in the development of the symbiotic biofilm. Thus, S. fredii SMH12 by means of a unique key molecule, the flavonoid, efficiently forms biofilm, colonizes the legume roots and activates the synthesis of Nod factors, required for successfully symbiosis.

  16. SoyBase and the legume information system: accessing information about the soybean and other legume genomes

    Science.gov (United States)

    This review describes two websites relevant for soybean research: SoyBase, and the Legume Information System (LIS). SoyBase and LIS have different objectives and areas of emphasis. SoyBase holds a wide range of specialized data in support of soybean breeding and research activities, with the primary...

  17. A modified Lotka-Volterra model for the evolution of coordinate symbiosis in energy enterprise

    Science.gov (United States)

    Zhou, Li; Wang, Teng; Lyu, Xiaohuan; Yu, Jing

    2018-02-01

    Recent developments in energy markets make the operating industries more dynamic and complex, and energy enterprises cooperate more closely in the industrial chain and symbiosis. In order to further discuss the evolution of coordinate symbiosis in energy enterprises, a modified Lotka-Volterra equation is introduced to develop a symbiosis analysis model of energy groups. According to the equilibrium and stability analysis, a conclusion is obtained that if the upstream energy group and the downstream energy group are in symbiotic state, the growth of their utility will be greater than their independent value. Energy enterprises can get mutual benefits and positive promotions in industrial chain by their cooperation.

  18. Industrial symbiosis as a countermeasure for resource dependent city: a case study of Guiyang, China

    DEFF Research Database (Denmark)

    Li, Hong; Dong, Liang; Ren, Jingzheng

    2015-01-01

    as example of industrial and regional symbiosis focusing on the integration and symbiosis of coal, electricity, aluminum, phosphor chemical, iron/steel industry and urban. Then, a quantitative assessment on the environmental benefits has been conducted based on material flow analysis approach. Results...... highlight a dramatic resource saving, solid waste reduction and carbon dioxide emission mitigation, as well as generating revenue for companies and local business opportunities. Finally, policy implications for promoting the industry symbiosis are discussed in details. Our research provides an efficacious...

  19. Evolution of Fungal enzymes in the attine ant symbiosis

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard; Schiøtt, Morten; Boomsma, Jacobus Jan

    The attine ant symbiosis is characterized by ancient but varying degrees of diffuse co-evolution between the ants and their fungal cultivars. Domesticated fungi became dependent on vertical transmission by queens and the ant colonies came to rely on their symbiotic fungus for food and thus......, indirectly, on fungal enzymes to break down the plant material brought in by the ants as fungal substrate. The more than 210 extant fungus-growing ant species differ considerably in colony size, social complexity and substrate-use. Only the derived leaf-cutting ants are specialized on using fresh leaves...... as garden substrate, whereas the more basal genera use leaf litter, insect feces and insect carcasses. We hypothesized that enzyme activity of fungal symbionts has co-evolved with substrate use and we measured enzyme activities of fungus gardens in the field to test this, focusing particularly on plant...

  20. The United States and Israel, from alliance to symbiosis

    Directory of Open Access Journals (Sweden)

    Ferran Izquierdo Brichs

    2003-12-01

    Full Text Available The relationship between Israel and the United States has been evolving from that of an alliance during the Cold War to a symbiosis nowadays. American policy toward the Middle East is marked by its interest in oil, to which its growing relationship with Israelhas gradually been added. However, although for a long time the interests it shared with Saudi Arabia and other Arab countries moderated its policy and balanced its support of Israel somewhat, in the last few years its alliance with Israel has come to dominate Washington’s strategy. This is reflected in its invasion of Iraq and its tensions with Arab countries. The reason for this evolution must be sought, primarily, in the influence that Israel and pro-Zionist lobbies have gained in the domestic policy of the United States.

  1. Harnessing mosquito-Wolbachia symbiosis for vector and disease control.

    Science.gov (United States)

    Bourtzis, Kostas; Dobson, Stephen L; Xi, Zhiyong; Rasgon, Jason L; Calvitti, Maurizio; Moreira, Luciano A; Bossin, Hervé C; Moretti, Riccardo; Baton, Luke Anthony; Hughes, Grant L; Mavingui, Patrick; Gilles, Jeremie R L

    2014-04-01

    Mosquito species, members of the genera Aedes, Anopheles and Culex, are the major vectors of human pathogens including protozoa (Plasmodium sp.), filariae and of a variety of viruses (causing dengue, chikungunya, yellow fever, West Nile). There is lack of efficient methods and tools to treat many of the diseases caused by these major human pathogens, since no efficient vaccines or drugs are available; even in malaria where insecticide use and drug therapies have reduced incidence, 219 million cases still occurred in 2010. Therefore efforts are currently focused on the control of vector populations. Insecticides alone are insufficient to control mosquito populations since reduced susceptibility and even resistance is being observed more and more frequently. There is also increased concern about the toxic effects of insecticides on non-target (even beneficial) insect populations, on humans and the environment. During recent years, the role of symbionts in the biology, ecology and evolution of insect species has been well-documented and has led to suggestions that they could potentially be used as tools to control pests and therefore diseases. Wolbachia is perhaps the most renowned insect symbiont, mainly due to its ability to manipulate insect reproduction and to interfere with major human pathogens thus providing new avenues for pest control. We herein present recent achievements in the field of mosquito-Wolbachia symbiosis with an emphasis on Aedes albopictus. We also discuss how Wolbachia symbiosis can be harnessed for vector control as well as the potential to combine the sterile insect technique and Wolbachia-based approaches for the enhancement of population suppression programs. Copyright © 2013 International Atomic Energy Agency 2013. Published by Elsevier B.V. All rights reserved.

  2. Lichen symbiosis: nature's high yielding machines for induced hydrogen production.

    Directory of Open Access Journals (Sweden)

    Aikaterini Papazi

    Full Text Available Hydrogen is a promising future energy source. Although the ability of green algae to produce hydrogen has long been recognized (since 1939 and several biotechnological applications have been attempted, the greatest obstacle, being the O2-sensitivity of the hydrogenase enzyme, has not yet been overcome. In the present contribution, 75 years after the first report on algal hydrogen production, taking advantage of a natural mechanism of oxygen balance, we demonstrate high hydrogen yields by lichens. Lichens have been selected as the ideal organisms in nature for hydrogen production, since they consist of a mycobiont and a photobiont in symbiosis. It has been hypothesized that the mycobiont's and photobiont's consumption of oxygen (increase of COX and AOX proteins of mitochondrial respiratory pathways and PTOX protein of chrolorespiration establishes the required anoxic conditions for the activation of the phycobiont's hydrogenase in a closed system. Our results clearly supported the above hypothesis, showing that lichens have the ability to activate appropriate bioenergetic pathways depending on the specific incubation conditions. Under light conditions, they successfully use the PSII-dependent and the PSII-independent pathways (decrease of D1 protein and parallel increase of PSaA protein to transfer electrons to hydrogenase, while under dark conditions, lichens use the PFOR enzyme and the dark fermentative pathway to supply electrons to hydrogenase. These advantages of lichen symbiosis in combination with their ability to survive in extreme environments (while in a dry state constitute them as unique and valuable hydrogen producing natural factories and pave the way for future biotechnological applications.

  3. Lichen Symbiosis: Nature's High Yielding Machines for Induced Hydrogen Production

    Science.gov (United States)

    Papazi, Aikaterini; Kastanaki, Elizabeth; Pirintsos, Stergios; Kotzabasis, Kiriakos

    2015-01-01

    Hydrogen is a promising future energy source. Although the ability of green algae to produce hydrogen has long been recognized (since 1939) and several biotechnological applications have been attempted, the greatest obstacle, being the O2-sensitivity of the hydrogenase enzyme, has not yet been overcome. In the present contribution, 75 years after the first report on algal hydrogen production, taking advantage of a natural mechanism of oxygen balance, we demonstrate high hydrogen yields by lichens. Lichens have been selected as the ideal organisms in nature for hydrogen production, since they consist of a mycobiont and a photobiont in symbiosis. It has been hypothesized that the mycobiont’s and photobiont’s consumption of oxygen (increase of COX and AOX proteins of mitochondrial respiratory pathways and PTOX protein of chrolorespiration) establishes the required anoxic conditions for the activation of the phycobiont’s hydrogenase in a closed system. Our results clearly supported the above hypothesis, showing that lichens have the ability to activate appropriate bioenergetic pathways depending on the specific incubation conditions. Under light conditions, they successfully use the PSII-dependent and the PSII-independent pathways (decrease of D1 protein and parallel increase of PSaA protein) to transfer electrons to hydrogenase, while under dark conditions, lichens use the PFOR enzyme and the dark fermentative pathway to supply electrons to hydrogenase. These advantages of lichen symbiosis in combination with their ability to survive in extreme environments (while in a dry state) constitute them as unique and valuable hydrogen producing natural factories and pave the way for future biotechnological applications. PMID:25826211

  4. The ambrosia symbiosis is specific in some species and promiscuous in others: evidence from community pyrosequencing

    Czech Academy of Sciences Publication Activity Database

    Kostovčík, Martin; Bateman, C.C.; Kolařík, Miroslav; Stelinski, L.L.; Jordal, B.H.; Hulcr, J.

    2015-01-01

    Roč. 9, č. 1 (2015), s. 126-138 ISSN 1751-7362 Institutional support: RVO:61388971 Keywords : ambrosia symbiosis * pyrosequencing Subject RIV: EE - Microbiology, Virology Impact factor: 9.328, year: 2015

  5. Ensuring sustainable grain legume-cereal cropping systems

    DEFF Research Database (Denmark)

    Bedoussac, Laurent; Journet, E-P; Hauggaard-Nielsen, Henrik

    2017-01-01

    distribution, the impact of pests and diseases, as well as vulnerability to poor soils, drought and other effects of climate change. This chapter summarises data from over 50 field experiments undertaken since 2001 on cereal-grain legume intercropping in 13 sites in southern and western France as well...... as in Denmark using spring and winter cereal-grain legume intercrops. Intercropping involves simultaneously growing two or more crops in the same field for a significant period of time. The practice is ancient as early records from many human societies all over the world have shown. Intercropping systems...... are estimated to still provide as much as 15–20% of the world’s food supply. The practice was widespread in some European farming systems up until the 1950s – before the so-called fossilisation of agriculture. At that time as much as 50 % of all available nitrogen (N) may have originated from symbiotic N2...

  6. Soil macrofauna in wooded pasture with legume trees

    Directory of Open Access Journals (Sweden)

    Lusimar Lamarte Gonzaga Galindo da Silva

    2015-07-01

    Full Text Available Grasslands afforestation aims at adding different soil uses in a way they become profitable for their owners. As such handling aims at minimizing impacts, the current study had as its goal the use of soil macrofauna in order to evaluate legume afforestation effects on the soil, regardless the depth. Thus, nitrogen fixing species were inserted onto grassland areas and the macrofauna collection was performed 6 years after their planting in the 0-10cm, 10-20cm and 20.30cm layers, in winter and summer. Leguminous influence was different between depths and times of the year. It mostly favors communities under "Mimosa" Genus treetops. Besides, the effects from climatic seasonal variations on invertebrates were mitigated by the implementation of such legume trees

  7. Production of resistant starch by enzymatic debranching in legume flours.

    Science.gov (United States)

    Morales-Medina, Rocío; Del Mar Muñío, María; Guadix, Emilia M; Guadix, Antonio

    2014-01-30

    Resistant starch (RS) was produced by enzymatic hydrolysis of flours from five different legumes: lentil, chickpea, faba bean, kidney bean and red kidney bean. Each legume was firstly treated thermally, then hydrolyzed with pullulanase for 24h at 50°C and pH 5 and lyophilized. At the end of each hydrolysis reaction, the RS amount ranged from 4.7% for red kidney beans to 7.5% for chickpeas. With respect to the curves of RS against hydrolysis time, a linear increase was observed initially and a plateau was generally achieved by the end of reaction. These curves were successfully modeled by a kinetic equation including three parameters: initial RS, RS at long operation time and a kinetic constant (k). Furthermore, the relative increase in hydrolysis, calculated using the kinetic parameters, was successfully correlated to the percentage of amylose. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. The engine of the reef: Photobiology of the coral-algal symbiosis

    Directory of Open Access Journals (Sweden)

    Melissa Susan Roth

    2014-08-01

    Full Text Available Coral reef ecosystems thrive in tropical oligotrophic oceans because of the relationship between corals and endosymbiotic dinoflagellate algae called Symbiodinium. Symbiodinium convert sunlight and carbon dioxide into organic carbon and oxygen to fuel coral growth and calcification, creating habitat for these diverse and productive ecosystems. Light is thus a key regulating factor shaping the productivity, physiology and ecology of the coral holobiont. Similar to all oxygenic photoautotrophs, Symbiodinium must safely harvest sunlight for photosynthesis and dissipate excess energy to prevent oxidative stress. Oxidative stress is caused by environmental stressors such as those associated with global climate change, and ultimately leads to breakdown of the coral-algal symbiosis known as coral bleaching. Recently, large-scale coral bleaching events have become pervasive and frequent threatening and endangering coral reefs. Because the coral-algal symbiosis is the biological engine producing the reef, the future of coral reef ecosystems depends on the ecophysiology of the symbiosis. This review examines the photobiology of the coral-algal symbiosis with particular focus on the photophysiological responses and timescales of corals and Symbiodinium. Additionally, this review summarizes the light environment and its dynamics, the vulnerability of the symbiosis to oxidative stress, the abiotic and biotic factors influencing photosynthesis, the diversity of the coral-algal symbiosis and recent advances in the field. Studies integrating physiology with the developing omics fields will provide new insights into the coral-algal symbiosis. Greater physiological and ecological understanding of the coral-algal symbiosis is needed for protection and conservation of coral reefs.

  9. Organizational Boundary Change in Industrial Symbiosis: Revisiting the Guitang Group in China

    Directory of Open Access Journals (Sweden)

    Lin Shi

    2017-06-01

    Full Text Available This study revisits the Guitang Group, one of the best known industrial symbiosis cases in the sugar industry. Our goal is to offer an evolutionary understanding of industrial symbiosis at the Guitang Group. This article focuses on the organizational boundary change of the Guitang Group over time, and acknowledges this process as one of the seven industrial symbiosis dynamics proposed by Boons et al. We offer a historical view of the critical forces behind Guitang’s industrial symbiosis evolution since the 1950s; particularly how these changes were influenced by broader economic and institutional contexts of importance in China. These insights include the role of institutionalized research and development (R&D as well as technology-oriented leadership as driving forces for Guitang’s innovation, particularly since the 1990s, when greater efficiency and productivity were emphasized, leading to the establishment of further symbiotic relationships in the company’s evolutionary process. As a result, the Guitang Group grew from 2 internal to 11 internal and external symbiotic exchanges and is now a conglomeration with more than 3000 employees generating more than 1 billion RMB (150 million USD in revenue annually. The driving forces of the Guitang Group’s industrial symbiosis evolution helped to create, disseminate and share information by continuously reinforcing the industrial symbiosis message as part of the Guitang Group’s business model and competitive strategy. In addition, state-level policies such as establishing the Guigang (the city where Guitang is located Eco-Industrial Park enabled industrial symbiosis in Guitang. This study provides prospects for future research on the organizational boundary change dynamic of industrial symbiosis in the sugar manufacturing industry and beyond.

  10. Physicochemical and organoleptic properties of cookies incorporated with legume flours

    Directory of Open Access Journals (Sweden)

    Sushma Thongram

    2016-12-01

    Full Text Available In developing countries like India, with increasing urbanization, the demand for processed food and bakery products particularly cookies command wide popularity in both urban and rural mass. Hence, an attempt was made to develop functionally and nutritionally improved cookies and the influence of the partial replacement of the wheat flour by legume on the quality characteristic of cookies was analyzed. Six blends were prepared by homogenously mixing chickpea flour, pigeon pea, moong bean flour, and cowpea flour with wheat flour in the percentage proportions: 100, 25:75, 25:75, 25:75, 25:75, and 10:10:10:10:60 (CPF:WWF, PF:WWF, MF:WWF, CF:WWF, and CPF:PF:MF:CF:WWF and later used to make cookies. Chemical and functional properties of the composite flours and chemical as well as sensory characteristics of cookies made from the above combinations were determined. The incorporation of legume flour significantly affected the physical, chemical, and phytonutrient parameters of the cookies. The results revealed that functional properties, viz. water absorption capacity, oil absorption capacity, and swelling property, increased with addition of legume flours. The physical analysis revealed that the diameter and height increased with the incorporation of legume flour. The results of the proximate composition showed that the A6 possesses highest percentage of proteins (13.42% and crude fat (22.90%, A5 contains maximum value of crude fiber (2.10% and DPPH radical scavenging activity (55.47%, A1 showed maximum moisture (10.60%, A2 total phenolic content (6.14 TAE mg/100 g, and A3 showed maximum ash (3.66%. Statistical results revealed that the addition of selected pulse flours and a combination of these whole flours do not have a significant effect (p > 0.05 on the sensory characteristics of cookies.

  11. IMPLEMENTATION OF DNA MARKERS TO IMPROVE BREEDING OF FORAGE LEGUMES

    OpenAIRE

    S. Grljušić; M. Tucak; T. Čupić; S. Popović

    2008-01-01

    The low rates of estimated genetic gains in forage legumes breeding have emphasized the need for new breeding methods that would increase efficiency in forage selection and provide reliable improvement. Information on application of molecular methodologies and tools for the enhancement of the current empirical phenotype-based selection moved us toward implementation of DNA markers to our breeding activities. Firstly, attention was given to identification of genetic variability within the fora...

  12. Effect of intercropping cereal crops with forage legumes and source ...

    African Journals Online (AJOL)

    Effect of intercropping cereal crops with forage legumes and source of nutrients on cereal grain yield and fodder dry matter yields. ... La disposition en lignes a produit un rendement élévé en fourrages secs (5%) et en grains des céréales que les céréales plantés aux hazard. La valeur nutritive (CP, NDF et degradabilité de ...

  13. Legume proteins, their nutritional improvement and screening techniques

    International Nuclear Information System (INIS)

    Boulter, D.; Evans, I.M.

    1976-01-01

    In assessing the nutritional limitation of legume proteins it is essential to consider both sulphur amino acids, methionine and cysteine. The possibility of using total seed sulphur as a criteria for screening for improved protein quality is discussed. In some species when relatively large amounts of S-methyl-cysteine are present, total sulphur determinations would be invalid unless that amino acid were extracted with ethanol before the sulphur determination. Methods for sulphur determination are discussed and evaluated. (author)

  14. Solubilisation of inorganic phosphates by inoculant strains from tropical legumes

    OpenAIRE

    Leandro Marciano Marra; Silvia Maria de Oliveira; Cláudio Roberto Fonsêca Sousa Soares; Fatima Maria de Souza Moreira

    2011-01-01

    Microbial solubilisation of low soluble inorganic phosphates is an important process contributing for the phosphorus available to plants in tropical soils. This study evaluates the ability of inoculant strains for tropical legumes to solubilise inorganic phosphates of low solubility that are found in tropical soils. Seven strains of Leguminosae nodulating bacteria (LNB) were compared with one another and with a non-nodulating positive control, Burkholderia cepacia (LMG 1222T). Four of the str...

  15. Some Root Traits of Barley (Hordeum vulgare L. as Affected by Mycorrhizal Symbiosis under Drought Stress

    Directory of Open Access Journals (Sweden)

    R. Bayani

    2016-05-01

    Full Text Available The effect of drought stress and mycorrhizal symbiosis on the colonization, root and leaf phosphorous content, root and leaf phosphatase activity, root volume and area as well as shoot dry weight of a variety of hulless barley were evaluated using a completely randomized experimental design (CRD with 3 replications. Treatments were three levels of drought stress of 30, 60 and 90% field capacity and two levels of mycorrhizal with and without inoculation. According to the results, the highest value of leaf phosphorous (1.54 mg/g was observed at mycorrhizal symbiosis against severe drought treatment. Root phosphatase activity was highest (297.9 OD min -1 FW-1 at severe drought stress with mycorrhizal symbiosis which in comparison with mild stress in the presence of mycorrhiza showed 16.6 fold increasing. The control and non-mycorrhizal symbiosis treatments had highest root dry weight (0.091 g. The lowest root volume (0.016 cm2 observed at mycorrhizal symbiosis × severe drought treatment. Generally, Inoculation of barley seed with mycorrhiza at severe water stress could transport more phosphorous to shoot, especially leaf via inducing of leaf and root phosphatase activity. Also, in addition to supply of nutrient sources especially phosphorous for plant, mycorrhizal symbiosis could play an important role in withstanding water stress in plant via increasing of root dry weight and area.

  16. IPD3 and IPD3L Function Redundantly in Rhizobial and Mycorrhizal Symbioses

    Directory of Open Access Journals (Sweden)

    Yue Jin

    2018-03-01

    Full Text Available Legume plants form symbiotic associations with either nitrogen-fixing bacteria or arbuscular mycorrhizal (AM fungi, which are regulated by a set of common symbiotic signaling pathway genes. Central to the signaling pathway is the activation of the DMI3/IPD3 protein complex by Ca2+ oscillations, and the initiation of nodule organogenesis and mycorrhizal symbiosis. DMI3 is essential for rhizobial infection and nodule organogenesis; however, ipd3 mutants have been shown to be impaired only in infection thread formation but not in root nodule organogenesis in Medicago truncatula. We identified an IPD3-like (IPD3L gene in the M. truncatula genome. A single ipd3l mutant exhibits a normal root nodule phenotype. The ipd3l/ipd3-2 double mutant is completely unable to initiate infection threads and nodule primordia. IPD3L can functionally replace IPD3 when expressed under the control of the IPD3 promoter, indicating functional redundancy between these two transcriptional regulators. We constructed a version of IPD3 that was phosphomimetic with respect to two conserved serine residues (IPD3-2D. This was sufficient to trigger root nodule organogenesis, but the increased multisite phosphorylation of IPD3 (IPD3-8D led to low transcriptional activity, suggesting that the phosphorylation levels of IPD3 fine-tune its transcriptional activity in the root nodule symbiosis. Intriguingly, the phosphomimetic version of IPD3 triggers spontaneous root-like nodules on the roots of dmi3-1 and dmi2-1 (DMI2 is an LRR-containing receptor-like kinase gene which is required for Ca2+ spiking, but not on the roots of wild-type or ipd3l ipd3-2 plants. In addition, fully developed arbuscules were formed in the ipd3l ipd3-2 mutants but not the ccamk/dmi3-1 mutants. Collectively, our data indicate that, in addition to IPD3 and IPD3L, another new genetic component or other new phosphorylation sites of IPD3 function downstream of DMI3 in rhizobial and mycorrhizal symbioses.

  17. Beneficial Effects of Temperate Forage Legumes that Contain Condensed Tannins

    Directory of Open Access Journals (Sweden)

    Jennifer W. MacAdam

    2015-07-01

    Full Text Available The two temperate forage legumes containing condensed tannins (CT that promote ruminant production are birdsfoot trefoil (Lotus corniculatus L.; BFT and sainfoin (Onobrychis viciifolia Scop.; SF. Both are well-adapted to the cool-temperate climate and alkaline soils of the Mountain West USA. Condensed tannins comprise a diverse family of bioactive chemicals with multiple beneficial functions for ruminants, including suppression of internal parasites and enteric methane. Birdsfoot trefoil contains 10 to 40 g·CT·kg−1 dry matter (DM, while SF contains 30 to 80 g·CT·kg−1 DM. Our studies have focused on these two plant species and have demonstrated consistently elevated rates of gain for beef calves grazing both BFT and SF. Novel results from our BFT research include carcass dressing percentages and consumer sensory evaluations equivalent to feedlot-finished steers and significantly greater than grass-finished steers, but with omega-3 fatty acid concentrations equal to grass-finished beef. We have further demonstrated that ruminants fed BFT or SF will consume more endophyte-infected tall fescue (Schedonorus arundinaceus (Schreb. Dumort. forage or seed than ruminants fed a non-CT forage legume. There is great potential value for sustainable livestock production in the use of highly digestible, nitrogen-fixing legumes containing tannins demonstrated to improve ruminant productivity.

  18. Tropical forage legumes for environmental benefits: An overview

    Directory of Open Access Journals (Sweden)

    Rainer Schultze-Kraft

    2018-01-01

    Full Text Available Ruminant livestock production in the tropics, particularly when based on pastures, is frequently blamed for being detrimental to the environment, allegedly contributing to: (1 degradation and destruction of ecosystems, including degradation and loss of soil, water and biodiversity; and (2 climate change (global warming. In this paper we argue that, rather than being detrimental, tropical forage legumes can have a positive impact on the environment, mainly due to key attributes that characterize the Leguminosae (Fabaceae family: (1 symbiotic nitrogen fixation; (2 high nutritive value; (3 deep-reaching tap-root system; (4 wide taxonomic and genetic diversity; and (5 presence of particular secondary metabolites. Although there are also potential negative aspects, such as soil acidification and the risks of introduced legumes becoming invasive weeds, we submit that legumes have potential to contribute significantly to sustainable intensification of livestock production in the tropics, along with the provision of ecosystem services. To further assess, document and realize this potential, research for development needs in a range of areas are indicated.

  19. Therapeutic Potential of Temperate Forage Legumes: A Review.

    Science.gov (United States)

    Cornara, Laura; Xiao, Jianbo; Burlando, Bruno

    2016-07-29

    The discovery of bioactive molecules from botanical sources is an expanding field, preferentially oriented to plants having a tradition of use in medicine and providing high yields and availability. Temperate forage legumes are Fabaceae species that include worldwide-important crops. These plants possess therapeutic virtues that have not only been used in veterinary and folk medicine, but have also attracted the interest of official medicine. We have examined here Medicago sativa (alfalfa), Trifolium pratense and T. repens (clovers), Melilotus albus and M. officinalis (sweet clovers), Lotus corniculatus (birdsfoot trefoil), Onobrychis viciifolia (sainfoin), Lespedeza capitata (roundhead lespedeza), and Galega officinalis (goat's rue). The phytochemical complexes of these species contain secondary metabolites whose pharmacological potentials deserve investigation. Major classes of compounds include alkaloids and amines, cyanogenic glycosides, flavonoids, coumarins, condensed tannins, and saponins. Some of these phytochemicals have been related to antihypercholesterolemia, antidiabetic, antimenopause, anti-inflammatory, antiedema, anthelmintic, and kidney protective effects. Two widely prescribed drugs have been developed starting from temperate forage legumes, namely, the antithrombotic warfarin, inspired from sweet clover's coumarin, and the antidiabetic metformin, a derivative of sainfoin's guanidine. Available evidence suggests that temperate forage legumes are a potentially important resource for the extraction of active principles to be used as nutraceuticals and pharmaceuticals.

  20. Effect of Radiation Processing on Protein Quality of Certain Legumes

    International Nuclear Information System (INIS)

    El-Niely, H.F.G

    2007-01-01

    The Effects of irradiation (dose levels of 5, 7.5 and 10 kGy) on nutritive characteristics of peas (Pisum satinum L), cow peas (Vigna unguiculata L.Walp), lentils (Lens culinaris Med), kidney beans (Phaseolus vulgaris L), and chickpeas (Cicer arietinurn L) were examined. Analyses included proximate composition, levels of anti-nutrients (phytic acid, tannins), available lysine (AL), in vitro protein digestibility (IVPD), and protein efficiency ratio (PER) in the growing rat. The results showed that moisture, crude protein, crude fat, crude fiber, and ash were unchanged by the irradiation. Radiation processing significantly (p<0.05) reduced the levels of phytic acid (PA), tannins (TN), and available lysine (AE). IVPD and PER were significantly enhanced in a dose-dependent manner, relative to unirradiated control samples, for all legumes. The data sets for each legume exhibited high correlation coefficients between radiation dose and PA, TN, AE, IVPD, and PER. These results demonstrate the benefits of irradiation on the nutritional properties of these legumes

  1. Solubilisation of inorganic phosphates by inoculant strains from tropical legumes

    Directory of Open Access Journals (Sweden)

    Leandro Marciano Marra

    2011-10-01

    Full Text Available Microbial solubilisation of low soluble inorganic phosphates is an important process contributing for the phosphorus available to plants in tropical soils. This study evaluates the ability of inoculant strains for tropical legumes to solubilise inorganic phosphates of low solubility that are found in tropical soils. Seven strains of Leguminosae nodulating bacteria (LNB were compared with one another and with a non-nodulating positive control, Burkholderia cepacia (LMG 1222T. Four of the strains are used as inoculants for cowpeas (Vigna unguiculata (Bradyrhizobium sp. UFLA 03-84; Bradyrhizobium elkani INPA 03-11B and Bradyrhizobium japonicum BR3267 or for common beans (Phaseolus vulgaris (Rhizobium tropici CIAT 899T. Rhizobium etli UFLA 02-100 and Rhizobium leguminosarum 316C10a are also efficient nodulators of beans and Cupriavidus taiwanensis LMG 19424T nodulates on Mimosa pudica. Two experiments, with solid and liquid media, were performed to determine whether the strains were able to solubilise CaHPO4, Al(H2PO43 or FePO4.2H2O. On solid GELP medium none of the strains dissolved FePO4.2H2O, but LMG 1222, UFLA 03-84 and CIAT 899 solubilised CaHPO4 particularly well. These strains, along with LMG 19424 and BR 3267, were also able to increase the solubility of Al(H2PO43. In liquid GELP medium, LMG 1222 solubilised all phosphate sources, but no legume nodulating strain could increase the solubility of Al(H2PO43. The strains CIAT 899 and UFLA 02-100 were the only legume nodulating bacteria able to solubilise the other phosphate sources in liquid media, dissolving both CaHPO4 and FePO4.2H2O. There was a negative correlation between the pH of the culture medium and the concentration of soluble phosphate when the phosphorus source was CaHPO4 or FePO4.2H2O. The contribution of these strains to increasing the phosphorus nutrition of legumes and non-legume plant species should be investigated further by in vivo experiments.

  2. Highly productive forage legume stands show no positive biodiversity effect on yield and N2-fixation

    DEFF Research Database (Denmark)

    Dhamala, Nawa Raj; Eriksen, Jørgen; Carlsson, Georg

    2017-01-01

    Background and aims While N fixation in diversified grasslands including forage legumes and non-legumes has been widely studied, N fixation in swards containing only forage legumes remains unclear. In this study, we investigated N fixation in pure stands and mixtures of three forage legumes....... Methodology N fixation, dry matter (DM) and nitrogen (N) yields were quantified in a field experiment for red clover (Trifolium pratense L.), white clover (Trifolium repens L.) and lucerne (Medicago sativa L.) pure stands and mixtures using the isotope dilution method. Results All three forage legume species...... derived most (around 85%) of their N from atmospheric N fixation (%Ndfa). However, no positive effect of species diversity was found in any of the mixtures. Species composition of the forage legume mixtures affected the amount of N from N fixation by affecting DM production and N accumulation...

  3. The mycorrhizal fungus Gigaspora margarita possesses a CuZn superoxide dismutase that is up-regulated during symbiosis with legume hosts.

    Science.gov (United States)

    Lanfranco, Luisa; Novero, Mara; Bonfante, Paola

    2005-04-01

    A full-length cDNA showing high similarity to previously described CuZn superoxide dismutases (SODs) was identified in an expressed sequence tag collection from germinated spores of the arbuscular mycorrhizal fungus Gigaspora margarita (BEG 34). The corresponding gene sequence, named GmarCuZnSOD, is composed of four exons. As revealed by heterologous complementation assays in a yeast mutant, GmarCuZnSOD encodes a functional polypeptide able to confer increased tolerance to oxidative stress. The GmarCuZnSOD RNA was differentially expressed during the fungal life cycle; highest transcript levels were found in fungal structures inside the roots as observed on two host plants, Lotus japonicus and Medicago truncatula. These structures also reacted positively to 3,3'-diaminobenzidine, used to localize H2O2 accumulation. This H2O2 is likely to be produced by CuZnSOD activity since treatment with a chelator of copper ions, generally used to inhibit CuZnSODs, strongly reduced the 3,3'-diaminobenzidine deposits. A slight induction of GmarCuZnSOD gene expression was also observed in germinated spores exposed to L. japonicus root exudates, although the response showed variation in independent samples. These results provide evidence of the occurrence, in an arbuscular mycorrhizal fungus, of a functional SOD gene that is modulated during the life cycle and may offer protection as a reactive oxygen species-inactivating system against localized host defense responses raised in arbuscule-containing cells.

  4. [A structural assessment of the role of the cell surface carbohydrates of Rhizobium in the Rhizobium/legume symbiosis]. Progress report, June 1989--June 1991

    Energy Technology Data Exchange (ETDEWEB)

    Hollingsworth, R.I.

    1991-12-31

    Research continued on the study of cell surface carbohydrates of Rhizobium. Objectives include: To characterize, at a structural level, the differences between the lipopolysaccharides of a representative number of strains from different Rhizobium species to determine which features of LPS structure are species-specific and might, therefore, be determinants of host specificity. Determine the effect(s) of nod gene induction on the structure of Rhizobium lipopolysaccharides and determine whether synthesis of a modified LPS molecule or a new surface glycoconjugate is initiated by nod gene induction. Develop a non-chemical means for rapidly screening large numbers of bacterial strains in order to determine which glycoconjugate structural features are conserved between strains of the same species. Provide the necessary structural information which, when coupled with developments in the rapidly expanding field of Rhizobium genetics, should lead to a clear understanding of the role of Rhizobium surface glycoconjugates in host/symbiont interactions. Progress is discussed.

  5. Potential of legume-based grassland–livestock systems in Europe: a review

    Science.gov (United States)

    Lüscher, A; Mueller-Harvey, I; Soussana, J F; Rees, R M; Peyraud, J L

    2014-01-01

    European grassland-based livestock production systems face the challenge of producing more meat and milk to meet increasing world demands and to achieve this using fewer resources. Legumes offer great potential for achieving these objectives. They have numerous features that can act together at different stages in the soil–plant–animal–atmosphere system, and these are most effective in mixed swards with a legume proportion of 30–50%. The resulting benefits include reduced dependence on fossil energy and industrial N-fertilizer, lower quantities of harmful emissions to the environment (greenhouse gases and nitrate), lower production costs, higher productivity and increased protein self-sufficiency. Some legume species offer opportunities for improving animal health with less medication, due to the presence of bioactive secondary metabolites. In addition, legumes may offer an adaptation option to rising atmospheric CO2 concentrations and climate change. Legumes generate these benefits at the level of the managed land-area unit and also at the level of the final product unit. However, legumes suffer from some limitations, and suggestions are made for future research to exploit more fully the opportunities that legumes can offer. In conclusion, the development of legume-based grassland–livestock systems undoubtedly constitutes one of the pillars for more sustainable and competitive ruminant production systems, and it can be expected that forage legumes will become more important in the future. PMID:26300574

  6. Potential of legume-based grassland-livestock systems in Europe: a review.

    Science.gov (United States)

    Lüscher, A; Mueller-Harvey, I; Soussana, J F; Rees, R M; Peyraud, J L

    2014-06-01

    European grassland-based livestock production systems face the challenge of producing more meat and milk to meet increasing world demands and to achieve this using fewer resources. Legumes offer great potential for achieving these objectives. They have numerous features that can act together at different stages in the soil-plant-animal-atmosphere system, and these are most effective in mixed swards with a legume proportion of 30-50%. The resulting benefits include reduced dependence on fossil energy and industrial N-fertilizer, lower quantities of harmful emissions to the environment (greenhouse gases and nitrate), lower production costs, higher productivity and increased protein self-sufficiency. Some legume species offer opportunities for improving animal health with less medication, due to the presence of bioactive secondary metabolites. In addition, legumes may offer an adaptation option to rising atmospheric CO 2 concentrations and climate change. Legumes generate these benefits at the level of the managed land-area unit and also at the level of the final product unit. However, legumes suffer from some limitations, and suggestions are made for future research to exploit more fully the opportunities that legumes can offer. In conclusion, the development of legume-based grassland-livestock systems undoubtedly constitutes one of the pillars for more sustainable and competitive ruminant production systems, and it can be expected that forage legumes will become more important in the future.

  7. Genetics of mycorrhizal symbiosis in winter wheat (Triticum aestivum).

    Science.gov (United States)

    Lehnert, Heike; Serfling, Albrecht; Enders, Matthias; Friedt, Wolfgang; Ordon, Frank

    2017-07-01

    Bread wheat (Triticum aestivum) is a major staple food and therefore of prime importance for feeding the Earth's growing population. Mycorrhiza is known to improve plant growth, but although extensive knowledge concerning the interaction between mycorrhizal fungi and plants is available, genotypic differences concerning the ability of wheat to form mycorrhizal symbiosis and quantitative trait loci (QTLs) involved in mycorrhization are largely unknown. Therefore, a diverse set of 94 bread wheat genotypes was evaluated with regard to root colonization by arbuscular mycorrhizal fungi. In order to identify genomic regions involved in mycorrhization, these genotypes were analyzed using the wheat 90k iSelect chip, resulting in 17 823 polymorphic mapped markers, which were used in a genome-wide association study. Significant genotypic differences (P colonization, representing six QTL regions, were detected on chromosomes 3A, 4A and 7A, and candidate genes located in these QTL regions were proposed. The results reported here provide key insights into the genetics of root colonization by mycorrhizal fungi in wheat. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  8. Algal ancestor of land plants was preadapted for symbiosis.

    Science.gov (United States)

    Delaux, Pierre-Marc; Radhakrishnan, Guru V; Jayaraman, Dhileepkumar; Cheema, Jitender; Malbreil, Mathilde; Volkening, Jeremy D; Sekimoto, Hiroyuki; Nishiyama, Tomoaki; Melkonian, Michael; Pokorny, Lisa; Rothfels, Carl J; Sederoff, Heike Winter; Stevenson, Dennis W; Surek, Barbara; Zhang, Yong; Sussman, Michael R; Dunand, Christophe; Morris, Richard J; Roux, Christophe; Wong, Gane Ka-Shu; Oldroyd, Giles E D; Ané, Jean-Michel

    2015-10-27

    Colonization of land by plants was a major transition on Earth, but the developmental and genetic innovations required for this transition remain unknown. Physiological studies and the fossil record strongly suggest that the ability of the first land plants to form symbiotic associations with beneficial fungi was one of these critical innovations. In angiosperms, genes required for the perception and transduction of diffusible fungal signals for root colonization and for nutrient exchange have been characterized. However, the origin of these genes and their potential correlation with land colonization remain elusive. A comprehensive phylogenetic analysis of 259 transcriptomes and 10 green algal and basal land plant genomes, coupled with the characterization of the evolutionary path leading to the appearance of a key regulator, a calcium- and calmodulin-dependent protein kinase, showed that the symbiotic signaling pathway predated the first land plants. In contrast, downstream genes required for root colonization and their specific expression pattern probably appeared subsequent to the colonization of land. We conclude that the most recent common ancestor of extant land plants and green algae was preadapted for symbiotic associations. Subsequent improvement of this precursor stage in early land plants through rounds of gene duplication led to the acquisition of additional pathways and the ability to form a fully functional arbuscular mycorrhizal symbiosis.

  9. The dawn of symbiosis between plants and fungi.

    Science.gov (United States)

    Bidartondo, Martin I; Read, David J; Trappe, James M; Merckx, Vincent; Ligrone, Roberto; Duckett, Jeffrey G

    2011-08-23

    The colonization of land by plants relied on fundamental biological innovations, among which was symbiosis with fungi to enhance nutrient uptake. Here we present evidence that several species representing the earliest groups of land plants are symbiotic with fungi of the Mucoromycotina. This finding brings up the possibility that terrestrialization was facilitated by these fungi rather than, as conventionally proposed, by members of the Glomeromycota. Since the 1970s it has been assumed, largely from the observation that vascular plant fossils of the early Devonian (400 Ma) show arbuscule-like structures, that fungi of the Glomeromycota were the earliest to form mycorrhizas, and evolutionary trees have, until now, placed Glomeromycota as the oldest known lineage of endomycorrhizal fungi. Our observation that Endogone-like fungi are widely associated with the earliest branching land plants, and give way to glomeromycotan fungi in later lineages, raises the new hypothesis that members of the Mucoromycotina rather than the Glomeromycota enabled the establishment and growth of early land colonists. This journal is © 2011 The Royal Society

  10. On Pose Estimation for Human-Robot Symbiosis

    Directory of Open Access Journals (Sweden)

    Md. Al-Amin Bhuiyan

    2008-03-01

    Full Text Available This paper presents a vision based pose estimation system using knowledge based approach for human-robot symbiosis. The system is based on visual information of the face by connected component analysis of the skin color segmentation of images in HSV color model and is commenced with the face recognition and pose classification scheme using subspace PCA based pattern-matching strategies. With the knowledge of the known user's profile, face poses are then classified by multilayer perceptron. Based on the frame-based knowledge representation approach, face poses are being interpreted using the Software Platform for Agent and Knowledge (SPAK management. On face pose recognition, robot is then instructed to perform some specific tasks by issuing pose commands. Experimental results demonstrate that the subspace method is better than that of the standard PCA method for face pose classification. The system has been demonstrated with the implementation of the algorithm to interact with an entertainment robot named, AIBO for human-robot symbiotic relationship.

  11. Cell wall remodeling in mycorrhizal symbiosis: a way towards biotrophism.

    Science.gov (United States)

    Balestrini, Raffaella; Bonfante, Paola

    2014-01-01

    Cell walls are deeply involved in the molecular talk between partners during plant and microbe interactions, and their role in mycorrhizae, i.e., the widespread symbiotic associations established between plant roots and soil fungi, has been investigated extensively. All mycorrhizal interactions achieve full symbiotic functionality through the development of an extensive contact surface between the plant and fungal cells, where signals and nutrients are exchanged. The exchange of molecules between the fungal and the plant cytoplasm takes place both through their plasma membranes and their cell walls; a functional compartment, known as the symbiotic interface, is thus defined. Among all the symbiotic interfaces, the complex intracellular interface of arbuscular mycorrhizal (AM) symbiosis has received a great deal of attention since its first description. Here, in fact, the host plasma membrane invaginates and proliferates around all the developing intracellular fungal structures, and cell wall material is laid down between this membrane and the fungal cell surface. By contrast, in ectomycorrhizae (ECM), where the fungus grows outside and between the root cells, plant and fungal cell walls are always in direct contact and form the interface between the two partners. The organization and composition of cell walls within the interface compartment is a topic that has attracted widespread attention, both in ecto- and endomycorrhizae. The aim of this review is to provide a general overview of the current knowledge on this topic by integrating morphological observations, which have illustrated cell wall features during mycorrhizal interactions, with the current data produced by genomic and transcriptomic approaches.

  12. Metabolic symbiosis in cancer: refocusing the Warburg lens.

    Science.gov (United States)

    Nakajima, Erica C; Van Houten, Bennett

    2013-05-01

    Using relatively primitive tools in the 1920s, Otto Warburg demonstrated that tumor cells show an increased dependence on glycolysis to meet their energy needs, regardless of whether they were well-oxygenated or not. High rates of glucose uptake, fueling glycolysis, are now used clinically to identify cancer cells. However, the Warburg effect does not account for the metabolic diversity that has been observed amongst cancer cells nor the influences that might direct such diversity. Modern tools have shown that the oncogenes, variable hypoxia levels, and the utilization of different carbon sources affect tumor evolution. These influences may produce metabolic symbiosis, in which lactate from a hypoxic, glycolytic tumor cell population fuels ATP production in the oxygenated region of a tumor. Lactate, once considered a waste product of glycolysis, is an important metabolite for oxidative phosphorylation in many tissues. While much is known about how muscle and the brain use lactate in oxidative phosphorylation, the contribution of lactate in tumor bioenergetics is less defined. A refocused perspective of cancer metabolism that recognizes metabolic diversity within a tumor offers novel therapeutic targets by which cancer cells may be starved from their fuel sources, and thereby become more sensitive to traditional cancer treatments. Copyright © 2012 Wiley Periodicals, Inc.

  13. Comparative sequence analysis of nitrogen fixation-related genes in six legumes

    Directory of Open Access Journals (Sweden)

    Dong Hyun eKim

    2013-08-01

    Full Text Available Legumes play an important role as food and forage crops in international agriculture especially in developing countries. Legumes have a unique biological process called nitrogen fixation (NF by which they convert atmospheric nitrogen to ammonia. Although legume genomes have undergone polyploidization, duplication and divergence, NF-related genes, because of their essential functional role for legumes, might have remained conserved. To understand the relationship of divergence and evolutionary processes in legumes, this study analyzes orthologs and paralogs for selected 20 NF-related genes by using comparative genomic approaches in six legumes i.e. Medicago truncatula (Mt, Cicer arietinum, Lotus japonicus, Cajanus cajan (Cc, Phaseolus vulgaris (Pv and Glycine max (Gm. Subsequently, sequence distances, numbers of synonymous substitutions per synonymous site (Ks and nonsynonymous substitutions per nonsynonymous site (Ka between orthologs and paralogs were calculated and compared across legumes. These analyses suggest the closest relationship between Gm and Cc and the farthest distance between Mt and Pv in 6 legumes. Ks proportional plots clearly showed ancient genome duplication in all legumes, whole genome duplication event in Gm and also speciation pattern in different legumes. This study also reported some interesting observations e.g. no peak at Ks 0.4 in Gm-Gm, location of two independent genes next to each other in Mt and low Ks values for outparalogs for three genes as compared to other 12 genes. In summary, this study underlines the importance of NF-related genes and provides important insights in genome organization and evolutionary aspects of six legume species analyzed.

  14. Nodulation and N2 fixation effectiveness of Bradyrhizobium strains in symbiosis with Adzuki Bean, Vigna angularis

    Directory of Open Access Journals (Sweden)

    Dušica Delić

    2010-04-01

    Full Text Available In pot experiment, one isolate Knj from a Serbian soil, four strains of Bradyrhizobium japonicum and three strains of Bradyrhizobium spp. were examined for the effect on adzuki bean nodulation and effectiveness in symbiotic N2 fixation. All the tested strains produced root nodules in adzuki bean. Strains of B. japonicum showed high potential of N2 fixation, particularly 525 and 542. B. japonicum strains resulted 65-71% shoot dry weight and 99-138% total N content of uninoculated control with full N content (100%. No significant difference was found between the plants inoculated with Bradyrhizobium spp. strains and uninoculated control plants without N (40-42 and 42% shoot dry weight, respectively, which indicated symbiotic N2 fixation inactivity of the Bradyrhizobium spp. strains. Knj strain had the middle position (56% shoot dry weight. These data showed that B. japonicum 525 and 542 strains could be used in further investigations in order to apply them as inoculants in microbiological N fertilizers.

  15. Consumo de frutas, verduras e legumes por gestantes adolescentes

    Directory of Open Access Journals (Sweden)

    Antônia Caroline Diniz Brito

    2016-11-01

    Full Text Available Objetivo: Determinar o estado nutricional e os fatores associados ao consumo alimentar de frutas, verduras e legumes por gestantes adolescentes atendidas em um serviço público de referência para assistência pré-natal. Métodos: Estudo transversal e analítico, com 73 gestantes adolescentes de 10 a 19 anos, atendidas no Núcleo de Assistência ao Adolescente (NASA do Hospital Materno Infantil, em São Luís, Maranhão. Utilizou-se o Questionário de Frequência de Consumo Alimentar (QFCA, medidas antropométricas (peso, altura, índice de massa corporal - IMC - pré-gravídico e gravídico e questionário socioeconômico. As variáveis dependentes foram o consumo de frutas, verduras e legumes, e as independentes foram escolaridade, estado civil, raça, renda, situação demográfica, dados gestacionais e antropométricos. Resultados: Observou-se que 39,7% apresentaram IMC pré-gestacional de desnutrição, 50,7% de eutrofia, e menos de 10% sobrepeso ou obesidade. Para o IMC gestacional, os valores se alteraram, com 27,4% das gestantes desnutridas, 57,5% eutróficas e 15,1% com sobrepeso. Observou-se que os maiores percentuais de adequação para o consumo de frutas, verduras e legumes foram em adolescentes casadas ou em união estável (65,4%, que não trabalhavam (92,3% e com renda familiar menor que 1 salário mínimo (84,62%. Entretanto, a única associação positiva encontrada com o consumo de frutas, verduras e legumes foi o início do pré-natal. Conclusão: A maior parte das gestantes avaliadas apresentou-se eutrófica, apesar de cerca de um quarto apresentar baixo peso durante a gestação. Além disso, elas não consumiam uma dieta balanceada, com uma ingestão abaixo do recomendado de FVL. Entre os fatores relacionados a um melhor consumo de FVL destaca-se o início do acompanhamento pré-natal no primeiro trimestre.

  16. [Genome editing technology and its application in forage legumes].

    Science.gov (United States)

    Liu, Huan; Meng, Yingying; Niu, Lifang; Lin, Hao

    2017-10-25

    Genome editing is a novel targeted genome modification biotechnology, which could successfully mutate specific loci as well as generate gene replacement and insertion in various organisms. So far, genome editing technology has been widely applied in investigating gene function and developing valuable traits in both model plants and major crops. In this review, we briefly survey the historical development of genome editing technology, summarize recent progress using the CRISPR/Cas9 system for plant genome editing and explore the potential of the CRISPR/Cas technology in improving forage legumes.

  17. Preliminary Design of Industrial Symbiosis of Smes Using Material Flow Cost Accounting (MFCA) Method

    Science.gov (United States)

    Astuti, Rahayu Siwi Dwi; Astuti, Arieyanti Dwi; Hadiyanto

    2018-02-01

    Industrial symbiosis is a collaboration of several industries to share their necessities such material, energy, technology as well as waste management. As a part of industrial ecology, in principle, this system attempts to emulate ecosystem where waste of an organism is being used by another organism, therefore there is no waste in the nature. This system becomes an effort to optimize resources (material and energy) as well as minimize waste. Considerable, in a symbiosis incure material and energy flows among industries. Material and energy in an industry are known as cost carriers, thus flow analysis in this system can be conducted in perspective of material, energy and cost, or called as material flow cost accounting (MFCA) that is an economic and ecological appraisal approach. Previous researches shown that MFCA implementation could be used to evaluate an industry's environmental-related efficiency as well as in planning, business control and decision making. Moreover, the MFCA has been extended to assess environmental performance of SMEs Cluster or industrial symbiosis in SMEs Cluster, even to make preliminary design of an industrial symbiosis base on a major industry. This paper describes the use of MFCA to asses performance of SMEs industrial symbiosis and to improve the performance.

  18. Preliminary Design of Industrial Symbiosis of Smes Using Material Flow Cost Accounting (MFCA Method

    Directory of Open Access Journals (Sweden)

    Siwi Dwi Astuti Rahayu

    2018-01-01

    Full Text Available Industrial symbiosis is a collaboration of several industries to share their necessities such material, energy, technology as well as waste management. As a part of industrial ecology, in principle, this system attempts to emulate ecosystem where waste of an organism is being used by another organism, therefore there is no waste in the nature. This system becomes an effort to optimize resources (material and energy as well as minimize waste. Considerable, in a symbiosis incure material and energy flows among industries. Material and energy in an industry are known as cost carriers, thus flow analysis in this system can be conducted in perspective of material, energy and cost, or called as material flow cost accounting (MFCA that is an economic and ecological appraisal approach. Previous researches shown that MFCA implementation could be used to evaluate an industry’s environmental-related efficiency as well as in planning, business control and decision making. Moreover, the MFCA has been extended to assess environmental performance of SMEs Cluster or industrial symbiosis in SMEs Cluster, even to make preliminary design of an industrial symbiosis base on a major industry. This paper describes the use of MFCA to asses performance of SMEs industrial symbiosis and to improve the performance.

  19. Promoting low-carbon city through industrial symbiosis: A case in China by applying HPIMO model

    International Nuclear Information System (INIS)

    Dong, Liang; Fujita, Tsuyoshi; Zhang, Hui; Dai, Ming; Fujii, Minoru; Ohnishi, Satoshi; Geng, Yong; Liu, Zhu

    2013-01-01

    China launched low-carbon city strategy to respond global climate change. Industrial symbiosis (IS) could generate both economic and environmental benefits in clustered industries and communities. This research shed light on how industrial symbiosis contributes to city's low-carbon development. An urban-level hybrid physical input and monetary output (HPIMO) model which covers physical energy inputs and air pollutants emissions, is established for addressing case study in a Chinese typical industrial city (Liuzhou). Based on current energy consumption and industrial symbiosis and the application of HPIMO model, scenarios related to industrial symbiosis, including waste plastics recycling, scrap tires recycling, flying ash recycling and biomass utilization are explored. Results show that compared with business-as-usual (BAU) scenario, IS can reduce solid wastes and further contribute to the co-benefits of energy saving, CO 2 emissions reduction and air pollutants reduction. The finding is critical for national low-carbon strategy. Finally, policy implications to support the ever-improvement of IS promotion in China are proposed and discussed. - Highlights: • Industrial symbiosis could contribute to low-carbon city in terms of co-benefit. • Co-benefit of IS was in terms of waste reduction and air pollutants reduction. • Waste plastics recycling and biomass utilization generated large co-benefit. • Coal fly ash recycling reduced the solid waste while increased air pollutants. • The prices of wastes and facilities investment affected the total cost-benefit

  20. Response of native soil microbial functions to the controlled mycorrhization of an exotic tree legume, Acacia holosericea in a Sahelian ecosystem.

    Science.gov (United States)

    Bilgo, Ablasse; Sangare, Sheikh K; Thioulouse, Jean; Prin, Yves; Hien, Victor; Galiana, Antoine; Baudoin, Ezekeil; Hafidi, Mohamed; Bâ, Amadou M; Duponnois, Robin

    2012-04-01

    Fifty years of overexploitation have disturbed most forests within Sahelian areas. Exotic fast growing trees (i.e., Australian Acacia species) have subsequently been introduced for soil improvement and fuelwood production purposes. Additionally, rhizobial or mycorrhizal symbioses have sometimes been favored by means of controlled inoculations to increase the performance of these exotic trees in such arid and semiarid zones. Large-scale anthropogenic introduction of exotic plants could also threaten the native biodiversity and ecosystem resilience. We carried out an experimental reforestation in Burkina Faso in order to study the effects of Acacia holosericea mycorrhizal inoculation on the soil nutrient content, microbial soil functionalities and mycorrhizal soil potential. Treatments consisted of uninoculated A. holosericea, preplanting fertilizer application and arbuscular mycorrhizal inoculation with Glomus intraradices. Our results showed that (i) arbuscular mycorrhizal (AM) inoculation and prefertilizer application significantly improved A. holosericea growth after 4 years of plantation and (ii) the introduction of A. holosericea trees significantly modified soil microbial functions. The results clearly showed that the use of exotic tree legume species should be directly responsible for important changes in soil microbiota with great disturbances in essential functions driven by microbial communities (e.g., catabolic diversity and C cycling, phosphatase activity and P availability). They also highlighted the importance of AM symbiosis in the functioning of soils and forest plantation performances. The AM effect on soil functions was significantly correlated with the enhanced mycorrhizal soil potential recorded in the AM inoculation treatment. © Springer-Verlag 2011

  1. Distribution of native Legumes (Leguminoseae) in frequently burned longleaf pine (Pinaceae)-Wiregrass (Poaceae) ecosystems

    Science.gov (United States)

    Mark J. Hainds; Robert J. Mitchell; Brian J. Palik; Lindsay R. Boring; Dean H. Gjerstad

    1999-01-01

    Legume species distribution and abundance and selected environmental variables were quantified across a complex gradient (varying in both water-holding capacity and fertility) for frequently burned longleaf pine (Pinus palustris)-wiregrass (Aristida stricta) ecosystems. Legumes were present in all months; however, abundance...

  2. Tropical pasture legumes in southern Africa: A review. | J.H. | African ...

    African Journals Online (AJOL)

    Clipping trials have indicated that the use of tropical legumes could possibly be extended into drier areas and areas experiencing extremes of temperature. More intensive plant introduction, breeding and evaluation programmes are needed if the full potential of tropical legumes is to be realised. Keywords: adaptation ...

  3. Effects of legume reinforcement of veld on the performance of beef ...

    African Journals Online (AJOL)

    To measure the effect of legume reinforcement of veld on animal production, a 24 ha block of reverted granite sandveld dominated by Hyparrhenia filipendula was fenced into 8 equal-sized paddocks, 4 of which were seeded with legumes. Two paddocks were seeded in December 1971 with a mixture of Stylosanthes ...

  4. Some views on the potential for legume-based pastures in South ...

    African Journals Online (AJOL)

    The potential of South Africa for legume-based pastures is discussed in the light of available information. It is concluded that the potential is considerable and that most of this potential can be exploited by legume species available at present. With regard to suitable species, it is considered that temperates warrant most ...

  5. The effects of some raw tropical legume seeds on performance of ...

    African Journals Online (AJOL)

    An experiment was conducted to examine the effects of some raw legumes (jack beans, bambara groundnut and benne seeds) on performance characteristics, serum metabolites and organ morphology of exotic adult cockerels of gold mine strain. Each of the raw legumes replaced full fat soybean meal at 25% and 50% ...

  6. Influence of legume residue and nitrogen fertilizer on the growth and ...

    African Journals Online (AJOL)

    (11o38'N and 10o31'E) both in Bauchi state, during the rainy seasons of 2011 and 2012 to determine the influence of legume residue and nitrogen fertilizer on the growth and yield of sorghum (Sorghum bicolor (L.) Moench). The treatments consist of two legumes (cowpea and soybean), nitrogen fertilizer applied at the rate ...

  7. Determination of N2 -fixation ability of legume trees using the 15N method

    International Nuclear Information System (INIS)

    Wemay, Johannis; Syaukat, Sriharti; Sisworo, Elsje L

    1998-01-01

    A sequence field experiment has been conducted for determining the capability of N 2 -fixation by several legume trees. The experiment was designed using a randomize design with 4 replicates. Each replicate was planted with 100 legume trees and 100 non legume trees. The isotope plot, where 15 N was applied with 18 legume trees and 18 non legume trees. The planting distance was 1m x 1m. For the calculation of N 2 -fixation each legume and standard tree (Eucalypthus alba) was applied with 12.52g in the from of ammonium sulfate with 10.12% 15 N. The 15 N AS was applied in three splits 11 month earlier. Data obtained from this experiment showed that percentage of N derived from fixation (%N-dfF) of all legume trees was reasonable high. The legume trees used in this experiment were, Leucaena leucocephala, Acacia mangium, Caliandra tetragona, Flemengia congesta and Gliriciadia sepium with potential fixation from 62.31% to 90,68%. (author)

  8. Harvesting management options for legumes intercropped in napier grass in the central highlands of Kenya

    NARCIS (Netherlands)

    Mwangi, D.M.; Cadisch, G.; Thorpe, W.; Giller, K.E.

    2004-01-01

    Ways of promoting integration of herbaceous forage legumes into a napier grass fodder system were evaluated with the aim of increasing forage quantity and quality on smallholder dairy farms in central Kenya. The herbaceous legumes Desmodium intortum cv. Greenleaf (ILRI 104), Macrotyloma axillare cv.

  9. Will Elevated Carbon Dioxide Concentration Amplify the Benefits of Nitrogen Fixation in Legumes?

    Science.gov (United States)

    Current evidence suggests there are three key features of the response of legumes to elevated [CO2]: (1) unlike other non-leguminous C3 plants, only legumes have the potential to maximize the benefit of elevated [CO2] by matching stimulated photosynthesis with increased N2 fixation; (2) this potenti...

  10. Subsoil Nitrogen Capture in Mixed Legume Stands as Assessed by Deep Nitrogen-15 Placement

    NARCIS (Netherlands)

    Gathumbi, S.M.; Cadisch, G.; Buresh, R.J.; Giller, K.E.

    2003-01-01

    The rotation of crops with planted N2-fixing legumes (improved fallows) is a promising agroforestry innovation for replenishing soil fertility in the tropics. We postulated that woody and herbaceous legumes with different rooting and growth patterns could be mixed in improved fallows to maximize

  11. N2-fixing legumes are linked to enhanced mineral dissolution and microbiome modulations in Neotropical rainforests

    Science.gov (United States)

    Epihov, Dimitar; Batterman, Sarah; Hedin, Lars; Saltonstall, Kristin; Hall, Jefferson; Leake, Jonathan; Beerling, David

    2017-04-01

    Legumes represent the dominant family of many tropical forests with estimates of 120 billion legume trees in the Amazon basin alone. Many rainforest legume trees form symbioses with N2-fixing bacteria. In the process of atmospheric N2-fixation large amounts of nitrogen-rich litter are generated, supplying half of all nitrogen required to support secondary rainforest succession. However, it is unclear how N2-fixers affect the biogeochemical cycling of other essential nutrients by affecting the rates of mineral dissolution and rock weathering. Here we show that N2-fixing legumes in young Panamanian rainforests promote acidification and enhance silicate rock weathering by a factor of 2 compared to non-fixing trees. We report that N2-fixers also associate with enhanced dissolution of Al- and Fe-bearing secondary minerals native to tropical oxisols. In legume-rich neighbourhoods, non-fixers benefited from raised weathering rates relative to those of legume-free zones thus suggesting a positive community effect driven by N2-fixers. These changes in weathering potential were tracked by parallel functional and structural changes in the soil and rock microbiomes. Our findings support the view that N2-fixing legumes are central components of biogeochemical cycling, associated with enhanced release of Fe- and Al-bound P and primary mineral products (Mg, Mo). Rainforest legume services therefore bear important implications to short-term C cycling related to forest growth and the long-term C cycle related to marine carbonate deposition fuelled by silicate weathering.

  12. Characteristic elements of "Mediterranean Diet": the consumption of vegetables and legumes in Greece (1950-2005)

    NARCIS (Netherlands)

    Vasileiou, K.Z.; Sotiropoulos, I.; Georgakopoulos, G.

    2012-01-01

    on).This paper describes the dietary consumption of vegetables and legumes in Greece during the period 1950 to 2005. All dimensions of alimentary consumption patterns of vegetables and legumes are examined here with a specific focus on: a) their natural characteristics; b) technical features of the

  13. Shared skeletal support in a coral-hydroid symbiosis.

    Directory of Open Access Journals (Sweden)

    Olga Pantos

    Full Text Available Hydroids form symbiotic relationships with a range of invertebrate hosts. Where they live with colonial invertebrates such as corals or bryozoans the hydroids may benefit from the physical support and protection of their host's hard exoskeleton, but how they interact with them is unknown. Electron microscopy was used to investigate the physical interactions between the colonial hydroid Zanclea margaritae and its reef-building coral host Acropora muricata. The hydroid tissues extend below the coral tissue surface sitting in direct contact with the host's skeleton. Although this arrangement provides the hydroid with protective support, it also presents problems of potential interference with the coral's growth processes and exposes the hydroid to overgrowth and smothering. Desmocytes located within the epidermal layer of the hydroid's perisarc-free hydrorhizae fasten it to the coral skeleton. The large apical surface area of the desmocyte and high bifurcation of the distal end within the mesoglea, as well as the clustering of desmocytes suggests that a very strong attachment between the hydroid and the coral skeleton. This is the first study to provide a detailed description of how symbiotic hydroids attach to their host's skeleton, utilising it for physical support. Results suggest that the loss of perisarc, a characteristic commonly associated with symbiosis, allows the hydroid to utilise desmocytes for attachment. The use of these anchoring structures provides a dynamic method of attachment, facilitating detachment from the coral skeleton during extension, thereby avoiding overgrowth and smothering enabling the hydroid to remain within the host colony for prolonged periods of time.

  14. Environmental law and nuclear law: a growing symbiosis

    International Nuclear Information System (INIS)

    Ennerechts, S.

    2008-01-01

    This article is divided in two parts. The first part deals with the interrelationship between environmental law and nuclear law. It specifically addresses selective topics which the author considers as substantial proof that environmental law is in evidence in the nuclear field. These topics are access to nuclear information, public participation in nuclear decision-making and prevention and compensation of environmental damage caused by nuclear incidents. Environmental law will be considered in its narrow sense, meaning the law that seeks to protect nature such as soil, water, air and biodiversity. The position of the author is that the importance of environmental law for nuclear activities is increasing and may lead to a growing symbiosis with nuclear law. Environmental law and nuclear law share the same objectives: protection against mitigation of and compensation for damage to the environment. In the second part a specific problem that touches upon the extra-territorial effect of environmental legislation in the nuclear field will be examined. At the beginning of the 21. century, it can be expected that vendors of nuclear facilities will spare no efforts in trying to enter new markets all over the world. Countries with more developed environmental requirements on the construction of nuclear facilities by their national vendors in customer countries. This part of the article will analyse whether public international laws to the construction of nuclear facilities abroad. The author believes that there may well be a legal basis under customary international law justifying the application of national environmental law to the construction of nuclear facilities and the performance of work on nuclear facilities in foreign countries, but there would appear to be none permitting the enforcement of these laws in the absence of an agreement with the foreign country. (N.C.)

  15. forage systems mixed with forage legumes grazed by lactating cows

    Directory of Open Access Journals (Sweden)

    Clair Jorge Olivo

    2017-02-01

    Full Text Available Current research evaluates productivity, stocking and nutritional rates of three forage systems with Elephant Grass (EG + Italian Ryegrass (IR + Spontaneous Growth Species (SGS, without forage legumes; EG + IR + SGS + Forage Peanut (FP, mixed with FP; and EG + IR + SGS + Red Clover (RC, mixed with RC, in rotational grazing method by lactating cows. IR developed between rows of EG. FP was maintained, whilst RC was sow to respective forage systems. The experimental design was completely randomized, with three treatments and two replication, subdivided into parcels over time. Mean rate for forage yield and average stocking rate were 10.6, 11.6 and 14.4 t ha-1; 3.0, 2.8 and 3.1 animal unit ha-1 day-1, for the respective systems. Levels of crude protein and total digestible nutrients were 17.8, 18.7 and 17.5%; 66.5, 66.8 and 64.8%, for the respective forage systems. The presence of RC results in better and higher forage yield in the mixture, whilst FP results in greater control of SGS. The inclusion of forage legumes in pasture systems provides better nutritional rates.

  16. Utilization of induced mutations in improving legumes in Egypt

    International Nuclear Information System (INIS)

    Abo-Hegazi, A. M. T.

    1993-01-01

    More than one hundred articles published by Egyptian research workers dealing with the improvement of some seed-legumes through radiation, radioisotopes, chemical mutagens and induced mutations are briefly summarized and discussed from the point of view of a mutation breeder working in this field since 1961. Articles on faba bean (Vicia faba L.), soybean (Glycine Max L.), lentils (Lens culinaris), chick-pea (Cicer arietinum L.), lupin (Lupinus termis), peas=pea (Pisum sativum L.), cowpea (Vigna sinensis, savi), and fenugreek-helba (Trigonella foenum gracum L.) are reviewed. A very few number of promising mutations have been induced. However, none of them are utilized neither in conventional breeding programs nor as cultivars. This may be due to the lack of central plans and organization between efforts or research work being carried in various institutions. Joint plants and cooperation between research institutions, not only in Egypt but also among the Arab countries, are required in this field which may help in closing the wide gab between production and consumption os seed legumes. (author)

  17. Seed protein improvement in cereals and grain legumes

    International Nuclear Information System (INIS)

    1979-01-01

    Plant breeders, molecular biologists, analytical chemists and nutritionists report on progress and achievements to date. High-lysine genotypes of maize, barley and sorghum have been produced. One high-protein variety of wheat is reported available for commercial use. Grain legumes already have high seed protein content but, compared to cereals, less of the total biological yield is available as seed, and intensive efforts are being made to produce genotypes with higher seed yield. Genetic variability is available from world germplasm collections and from induced-mutation programmes. In the basic sciences considerable advances are reported. Putative structural genes determining protein quality and quantity have been located on various chromosomes. In vitro synthesis of legume and cereal storage proteins and the isolation of some mRNA and the preparation and cloning of cDNA have been reported. Uptake and incorporation of N into amino acids, their synthesis into proteins, and interaction between protein and carbohydrate biosynthesis during seed development are discussed. Future prospects are considered including potential selection at the cellular rather than the whole plant level. In only a minority of the 64 papers is the use of nuclear techniques indicated specifically enough to justify individual entries in INIS

  18. Improvement of native grassland by legumes introduction and tillage techniques

    Directory of Open Access Journals (Sweden)

    Syamsu Bahar

    1999-10-01

    Full Text Available A factorial design using three species of legumes (Siratro, Centro and Stylo and three different of tillage techniques (no-tillage, minimum tillage and total tillage was applied in this experiment. The results showed that there was no interaction between species and tillage techniques. There was significant reductions on bulk density from 1.23±0.03 g/cm3 (no-tillage to 1.07±0.02 g/cm3 (minimum tillage and 1.05±0.03 g/cm3 (total tillage. Also reductions on penetration resistance from 17.47±3.84 kg/cm2 (no-tillage to 3.31±0.43 kg/cm2 (minimum tillage and 3.19±0.45 kg/cm2 (total tillage. Otherwise significant increasing on aeration porosity from 12.80±0.80% vol. (no-tillage to 21.70±0.95% vol. (minimum tillage and 20.70±0.35% vol. (total tillage. Total tillage gives increased dry matter yield. Also both total tillage and minimum tillage give yields with a higher percentage of legumes compared with no-tillage. It was concluded that total tillage and minimum tillage could be used for improving native grassland.

  19. TRUNCATULIX--a data warehouse for the legume community.

    Science.gov (United States)

    Henckel, Kolja; Runte, Kai J; Bekel, Thomas; Dondrup, Michael; Jakobi, Tobias; Küster, Helge; Goesmann, Alexander

    2009-02-11

    Databases for either sequence, annotation, or microarray experiments data are extremely beneficial to the research community, as they centrally gather information from experiments performed by different scientists. However, data from different sources develop their full capacities only when combined. The idea of a data warehouse directly adresses this problem and solves it by integrating all required data into one single database - hence there are already many data warehouses available to genetics. For the model legume Medicago truncatula, there is currently no such single data warehouse that integrates all freely available gene sequences, the corresponding gene expression data, and annotation information. Thus, we created the data warehouse TRUNCATULIX, an integrative database of Medicago truncatula sequence and expression data. The TRUNCATULIX data warehouse integrates five public databases for gene sequences, and gene annotations, as well as a database for microarray expression data covering raw data, normalized datasets, and complete expression profiling experiments. It can be accessed via an AJAX-based web interface using a standard web browser. For the first time, users can now quickly search for specific genes and gene expression data in a huge database based on high-quality annotations. The results can be exported as Excel, HTML, or as csv files for further usage. The integration of sequence, annotation, and gene expression data from several Medicago truncatula databases in TRUNCATULIX provides the legume community with access to data and data mining capability not previously available. TRUNCATULIX is freely available at http://www.cebitec.uni-bielefeld.de/truncatulix/.

  20. Signals exchanged between legumes and Rhizobium: agricultural uses and perspectives

    International Nuclear Information System (INIS)

    Broughton, William J.; Perret, Xavier; Staehelin, Christian; Zhang Feng

    2001-01-01

    Legumes and rhizobia exchange at least three different, but sometimes complementary sets of signals. Amongst the variety of substances normally and continuously secreted into the rhizosphere by plants are phenolic compounds. Flavonoid components of these mixtures are especially active in inducing rhizobial nodulation genes. Many nodgenes exist. Some (e.g., nodD) serve as regulators of transcription, but most code for enzymes involved in the synthesis of a family of lipo-chito-oligosaccharides (LCOs) called Nod-factors. Nod-factors possess hormone-like properties, are key determinants in nodulation, and allow rhizobia to enter the plant. As Nod-factors also stimulate the synthesis and release of flavonoids from legume roots, the response to inoculation is amplified. Once the bacteria enter the plant, other sets of signals are exchanged between the symbionts. These include extra-cellular polysaccharides (EPSs) as well as proteins externalised via type-three secretion systems. These carbohydrates/proteins may be active in invasion of the root. At the time of writing, only flavonoids and Nodfactors have been chemically synthesised and of these only the former are available in large quantities. Field trials in North America show that seed application of flavonoids stimulates nodulation and nitrogen fixation in soybeans grown at low soil temperatures. The biological basis to these responses is discussed. (author)

  1. Legume Genome Initiative at the University of Oklahoma

    Energy Technology Data Exchange (ETDEWEB)

    Bruce A. Roe

    2004-02-27

    Consolidated Appropriations Resolution, 2003 Conference Report for the Department of Energy's Biological and Environmental Research (BER) program provided $481,000 for the Legume Genome Initiative at the University of Oklahoma. These funds were used to support our research that is aimed at determining the entire sequence of the gene rich regions of the genome of the legume, Medicago truncatula, by allowing us to obtain a greater degree of finished BAC sequences from the draft sequences we have already obtained through research funded by the Noble Foundation. During the funding period we increased the number of Medicago truncatula BACs with finished (Bermuda standard) sequences from 109 to 359, and the total number of BACs for which we collected sequence data from 584 to 842, 359 of which reached phase 2 (ordered and oriented contigs). We also sequenced a series of pooled BAC clones that cover additional euchromatic (gene rich) genomic regions. This work resulted in 6 refereed publications, see below. Genes whose sequence was determined during this study included multiple members of the plant disease resistance (R-gene) family as well as several genes involved in flavinoid biosynthesis, nitrogen fixation and plant-microbial symbosis. This work also served as a prelude to obtaining NSF funding for the international collaborative effort to complete the entire sequence of the Medicago truncatula genomic euchromatic regions using a BAC based approach.

  2. Tolerance of herbaceous summer legumes of temporary waterlogging

    Directory of Open Access Journals (Sweden)

    Elsa M. Ciotti

    2014-09-01

    Full Text Available A greenhouse study to evaluate adaptation of 4 herbaceous summer legumes to temporary waterlogging was conducted.  Species evaluated were Desmanthus virgatus and Aeschynomene americana in their vegetative stage, and Macroptilium lathyroides and M. atropurpureum in both vegetative and reproductive stages.  The experimental design was randomized blocks with 5 replications and treatments were:  T0, control; T1, saturation by capillary movement placing pots in buckets of 5 L with 10 cm of permanent water; and T2, flooding, placing pots in buckets of 10 L and a layer of water 5 cm above the soil.  The duration of the water treatments was 7 days. Waterlogging did not affect shoot or root biomass production nor nodulation in A. americana, whereas D. virgatus had its highest dry matter production in saturated soil (T1.  In M. lathyroides flooding tolerance was more evident in the reproductive than in the vegetative stage, probably due to more production of adventitious roots and formation of aerenchymatic tissue.  Macroptilium atropurpureum showed adaptation to temporary flooding.  Survival and quick recovery of these species would confirm their potential as forages for temporarily waterlogged soils.Keywords: Forage legumes, flooding, Aeschynomene americana, Desmanthus virgatus, Macroptilium lathyroides, Northeast Argentina.DOI: 10.17138/TGFT(2278-286

  3. Induced mutations for improvement of grain legume production

    International Nuclear Information System (INIS)

    1980-11-01

    After an introduction on plant science research in Malaysia concerning crop breeding, 22 research reports are presented, 17 of which are analyzed individually and constitute separate INIS references. The remaining 5 were essentially concerned with only future applications of nuclear technology: a paper by V.L. Chopra (India) on mutation breeding for partial disease resistance of wheat; by H.H. Hoppe (Federal Republic of Germany) on mechanisms of resistance against Uromyces in Phaseolus vulgaris; by I.S. Santos (Philippines) on induction evaluation and utilization of beneficial mutations in the winged bean (Psophocarpus tetragonolobus), where gamma rays and fast neutrons will be used as well as other mutagens; by F. Saccardo (Italy) on breeding for disease resistance in peas and other vegetables (short communication only); and by E. Balazs and I. Sziraki (Hungary) on in vitro studies on virus resistance of legumes, including virus-host interaction studies involving gamma irradiation (short communication only). The conclusions and recommendations of the Regional Seminar on Induced Mutations for the Improvement of Grain Legumes in S.E. Asia 1975 (IAEA-203, 1977) were considered and generally endorsed, with some clarification. Conclusions and recommendations are given on p.121-126

  4. Chemical identification and functional analysis of apocarotenoids involved in the development of arbuscular mycorrhizal symbiosis.

    Science.gov (United States)

    Akiyama, Kohki

    2007-06-01

    Arbuscular mycorrhizae formed between more than 80% of land plants and arbuscular mycorrhizal (AM) fungi represent the most widespread symbiosis on the earth. AM fungi facilitate the uptake of soil nutrients, especially phosphate, by plants, and in return obtain carbohydrates from hosts. Apocarotenoids, oxidative cleavage products of carotenoids, have been found to play a critical role in the establishment of AM symbiosis. Strigolactones previously isolated as seed-germination stimulants for root parasitic weeds act as a chemical signal for AM fungi during presymbiotic stages. Stimulation of carotenoid metabolism, leading to massive accumulation of mycorradicin and cyclohexenone derivatives, occurs during root colonization by AM fungi. This review highlights research into the chemical identification of arbuscular mycorrhiza-related apocarotenoids and their role in the regulation and establishment of AM symbiosis conducted in the past 10 years.

  5. Eco-Evo-Devo: developmental symbiosis and developmental plasticity as evolutionary agents.

    Science.gov (United States)

    Gilbert, Scott F; Bosch, Thomas C G; Ledón-Rettig, Cristina

    2015-10-01

    The integration of research from developmental biology and ecology into evolutionary theory has given rise to a relatively new field, ecological evolutionary developmental biology (Eco-Evo-Devo). This field integrates and organizes concepts such as developmental symbiosis, developmental plasticity, genetic accommodation, extragenic inheritance and niche construction. This Review highlights the roles that developmental symbiosis and developmental plasticity have in evolution. Developmental symbiosis can generate particular organs, can produce selectable genetic variation for the entire animal, can provide mechanisms for reproductive isolation, and may have facilitated evolutionary transitions. Developmental plasticity is crucial for generating novel phenotypes, facilitating evolutionary transitions and altered ecosystem dynamics, and promoting adaptive variation through genetic accommodation and niche construction. In emphasizing such non-genomic mechanisms of selectable and heritable variation, Eco-Evo-Devo presents a new layer of evolutionary synthesis.

  6. Farming legumes in the pre-pottery Neolithic: New discoveries from the site of Ahihud (Israel)

    Science.gov (United States)

    Vardi, Jacob; Paz, Ytzhak; Boaretto, Elisabetta

    2017-01-01

    New discoveries of legumes in the lower Galilee at the prehistoric site of Ahihud in Israel shed light on early farming systems in the southern Levant. Radiocarbon dating of twelve legumes from pits and floors indicate that the farming of legumes was practiced in southern Levant as early as 10.240–10.200 (1σ) ago. The legumes were collected from pits and other domestic contexts dated to the Early Pre-Pottery Neolithic B. The legumes identified include Vicia faba L. (faba bean), V. ervilia (bitter vetch), V. narbonensis (narbon vetch), Lens sp. (lentil), Pisum sp. (pea), Lathyrus inconspicuus (inconspicuous pea) and L. hirosolymitanus (jerusalem vetchling). Comparison with coeval sites in the region show how the presence of peas, narbon vetches, inconspicuous peas, jerusalem vetchlings and bitter vetches together with faba bean and lentils is unique to the Pre-Pottery Neolithic, and might indicate specific patterns in farming or storing at the onset of agriculture. PMID:28542358

  7. Farming legumes in the pre-pottery Neolithic: New discoveries from the site of Ahihud (Israel).

    Science.gov (United States)

    Caracuta, Valentina; Vardi, Jacob; Paz, Ytzhak; Boaretto, Elisabetta

    2017-01-01

    New discoveries of legumes in the lower Galilee at the prehistoric site of Ahihud in Israel shed light on early farming systems in the southern Levant. Radiocarbon dating of twelve legumes from pits and floors indicate that the farming of legumes was practiced in southern Levant as early as 10.240-10.200 (1σ) ago. The legumes were collected from pits and other domestic contexts dated to the Early Pre-Pottery Neolithic B. The legumes identified include Vicia faba L. (faba bean), V. ervilia (bitter vetch), V. narbonensis (narbon vetch), Lens sp. (lentil), Pisum sp. (pea), Lathyrus inconspicuus (inconspicuous pea) and L. hirosolymitanus (jerusalem vetchling). Comparison with coeval sites in the region show how the presence of peas, narbon vetches, inconspicuous peas, jerusalem vetchlings and bitter vetches together with faba bean and lentils is unique to the Pre-Pottery Neolithic, and might indicate specific patterns in farming or storing at the onset of agriculture.

  8. Farming legumes in the pre-pottery Neolithic: New discoveries from the site of Ahihud (Israel.

    Directory of Open Access Journals (Sweden)

    Valentina Caracuta

    Full Text Available New discoveries of legumes in the lower Galilee at the prehistoric site of Ahihud in Israel shed light on early farming systems in the southern Levant. Radiocarbon dating of twelve legumes from pits and floors indicate that the farming of legumes was practiced in southern Levant as early as 10.240-10.200 (1σ ago. The legumes were collected from pits and other domestic contexts dated to the Early Pre-Pottery Neolithic B. The legumes identified include Vicia faba L. (faba bean, V. ervilia (bitter vetch, V. narbonensis (narbon vetch, Lens sp. (lentil, Pisum sp. (pea, Lathyrus inconspicuus (inconspicuous pea and L. hirosolymitanus (jerusalem vetchling. Comparison with coeval sites in the region show how the presence of peas, narbon vetches, inconspicuous peas, jerusalem vetchlings and bitter vetches together with faba bean and lentils is unique to the Pre-Pottery Neolithic, and might indicate specific patterns in farming or storing at the onset of agriculture.

  9. Legume integration as an agroecological intensification option for smallholders in uplands of Southeast Asia

    DEFF Research Database (Denmark)

    Yap, Von Yi

    that the initial performance of ricebean was affected by drought and grazing livestock. The results also demonstrated that the top-down Farming Systems Research & Extension intervention approach by the extension agents in promoting the innovation of legume integration into maize-based cropping systems without...... availability, the financial status of the household and access to extension services were the major factors influencing the decisions of resource-poor maize smallholders in legume adoption. The type of intervention approach by the extension agents needs to be considered to ensure sustained adoption of legume...... innovation. Since extreme weather events caused by climate change are becoming more common and unpredictable, it is imperative to find ways to reduce the risks that farmers may face upon integrating legumes under variable weather conditions. The assessment of the sustainability and resilience of legume...

  10. The position of prenylation of isoflavonoids and stilbenoids from legumes (Fabaceae) modulates the antimicrobial activity against Gram positive pathogens

    NARCIS (Netherlands)

    Araya-Cloutier, Carla; Besten, den Heidy M.W.; Aisyah, Siti; Gruppen, Harry; Vincken, Jean Paul

    2017-01-01

    The legume plant family (Fabaceae) is a potential source of antimicrobial phytochemicals. Molecular diversity in phytochemicals of legume extracts was enhanced by germination and fungal elicitation of seven legume species, as established by RP-UHPLC–UV–MS. The relationship between phytochemical

  11. Examination of Industrial Symbiosis Potential Interactions in an Industrial Area Of NE Greece

    Directory of Open Access Journals (Sweden)

    G. Gaidajis

    2015-03-01

    Full Text Available This paper considers the potential contribution of Industrial Symbiosis in fostering environmental and economical benefits in the area of Nea Karvali, Kavala, Greece. Industrial Symbiosis describes the mutualistic interaction of different industries for beneficial reuse of waste flows or energy cascading that results in a more resource-efficient production system and fewer adverse environmental impacts. Results from the case study presented in this paper, show that the implementation of symbiotic relationships in the industrial area under study, would lead to significant environmental benefits (GHG reduction, reduction on natural sources consumption and would give a boost to the local economical sector by developing new business opportunities.

  12. Leveraging model legume information to find candidate genes for soybean sudden death syndrome using the legume information system.

    Science.gov (United States)

    Gonzales, Michael D; Gajendran, Kamal; Farmer, Andrew D; Archuleta, Eric; Beavis, William D

    2007-01-01

    Comparative genomics is an emerging and powerful approach to achieve crop improvement. Using comparative genomics, information from model plant species can accelerate the discovery of genes responsible for disease and pest resistance, tolerance to plant stresses such as drought, and enhanced nutritional value including production of anti-oxidants and anti-cancer compounds. We demonstrate here how to use the Legume Information System for a comparative genomics study, leveraging genomic information from Medicago truncatula (barrel medic), the model legume, to find candidate genes involved with sudden death syndrome (SDS) in Glycine max (soybean). Specifically, genetic maps, physical maps, and annotated tentative consensus and expressed sequence tag (EST) sequences from G. max and M. truncatula can be compared. In addition, the recently published M. truncatula genomic sequences can be used to identify M. truncatula candidate genes in a genomic region syntenic to a quantitative trait loci region for SDS in soybean. Genomic sequences of candidate genes from M. truncatula can then be used to identify ESTs with sequence similarities from soybean for primer design and cloning of potential soybean disease causing alleles.

  13. Nitrogen fixation in eukaryotes – New models for symbiosis

    Directory of Open Access Journals (Sweden)

    Lockhart Peter

    2007-04-01

    investigation of processes involved in the transition of symbionts to organelles. Extant lineages of symbiotic associations for nitrogen fixation show diverse grades of adaptation and co-evolution, thereby representing different stages of symbiont-host interaction. In particular cyanobacterial associations with protists, like the Rhopalodia gibba-spheroid body symbiosis, could serve as important model systems for the investigation of the complex mechanisms underlying organelle evolution.

  14. Transfer Comparison Study Nitrogen on the Intact and Decapitated Legumes by Using the 15N Labeling Technique

    International Nuclear Information System (INIS)

    Widjayanto, Didik W.

    1998-01-01

    The experiment was done in order to evaluate the N transfer from the intact and decapitated legumes by using the 15 N labeling technique. Seven days after final labeling the above ground biomass from labeled legume species was removed and the remaining stalks capped to prevent regrowth. Twenty days after final labeling (fourteen days after capping) the all treatments were sample and analyzed. The decapitated legumes appeared to transfer more percentage N than the intact legumes. Although both decapitated and intact legumes transferred, the transfer of N did not incur a dry matter and N yield benefit

  15. Proteomic Analysis of the Soybean Symbiosome Identifies New Symbiotic Proteins*

    Science.gov (United States)

    Clarke, Victoria C.; Loughlin, Patrick C.; Gavrin, Aleksandr; Chen, Chi; Brear, Ella M.; Day, David A.; Smith, Penelope M.C.

    2015-01-01

    Legumes form a symbiosis with rhizobia in which the plant provides an energy source to the rhizobia bacteria that it uses to fix atmospheric nitrogen. This nitrogen is provided to the legume plant, allowing it to grow without the addition of nitrogen fertilizer. As part of the symbiosis, the bacteria in the infected cells of a new root organ, the nodule, are surrounded by a plant-derived membrane, the symbiosome membrane, which becomes the interface between the symbionts. Fractions containing the symbiosome membrane (SM) and material from the lumen of the symbiosome (peribacteroid space or PBS) were isolated from soybean root nodules and analyzed using nongel proteomic techniques. Bicarbonate stripping and chloroform-methanol extraction of isolated SM were used to reduce complexity of the samples and enrich for hydrophobic integral membrane proteins. One hundred and ninety-seven proteins were identified as components of the SM, with an additional fifteen proteins identified from peripheral membrane and PBS protein fractions. Proteins involved in a range of cellular processes such as metabolism, protein folding and degradation, membrane trafficking, and solute transport were identified. These included a number of proteins previously localized to the SM, such as aquaglyceroporin nodulin 26, sulfate transporters, remorin, and Rab7 homologs. Among the proteome were a number of putative transporters for compounds such as sulfate, calcium, hydrogen ions, peptide/dicarboxylate, and nitrate, as well as transporters for which the substrate is not easy to predict. Analysis of the promoter activity for six genes encoding putative SM proteins showed nodule specific expression, with five showing expression only in infected cells. Localization of two proteins was confirmed using GFP-fusion experiments. The data have been deposited to the ProteomeXchange with identifier PXD001132. This proteome will provide a rich resource for the study of the legume-rhizobium symbiosis. PMID

  16. Study and analysis of the legume crop market in Armenia

    Directory of Open Access Journals (Sweden)

    Sarukhanyan Rafael

    2011-01-01

    Full Text Available In mountainous and sub-mountainous zones of the Republic of Armenia farmers mainly grow beans, chickpeas, and peas. In addition there are very small crop areas (mainly homestead lands of faba bean, soybean, mung bean, and grass pea. The village population does not know much about the cultivation of these plants. The data show that in 2007-2009 the specific weight of legume in overall cropland was approximately 94%, and about the 96% of the gross harvest. Local production needs appropriate marketing strategy. The research of local market showed that more attention should be paid to the consumption of goods produced by the farmer households, as well as to offer them to various consumer groups.

  17. Legume promotion in counselling: an e-mail survey of dietitians.

    Science.gov (United States)

    Desrochers, N; Brauer, P M

    2001-01-01

    Little is known about dietitians current practice in counselling clients about the use of legumes in a low fat, high fibre diet. An exploratory e-mail questionnaire was sent to members of Dietitians of Canada to assess: dietitian use and preferences for legumes, dietitian practice, opinions about clients attitudes and preferences, and resource needs. Counsellors (n=256) had high personal use of legumes (64% > or = 1 serving/week) and frequently recommended legumes in counselling. The legumes most preferred by respondents and their clients were: peanuts, kidney beans, split peas, chickpeas, and lentils. Respondents often recommended canned bean products (76%) and tofu (61%), but other legume grocery products were less often recommended. The most common client issues identified were: flatulence (87% agreed), lack of familiarity (85%), and knowledge of preparation (82%). Dietitians were not satisfied with current resources to support practice, especially those respondents providing primarily clinical counselling services. The most requested resources were: recipes (90%), pamphlets (82%), food demonstrations (75%) and Internet sites (63%). Client level research is now needed to confirm the importance of the issues identified and to develop and test strategies for legume promotion in counselling.

  18. Biochemical characterization of legume seeds as ingredients in animal feed

    Energy Technology Data Exchange (ETDEWEB)

    Martín-Pedrosa, M.; Varela, A.; Guillamon, E.; Cabellos, B.; Burbano, C.; Gomez-Fernandez, J.; Mercado, E. de; Gomez-Izquierdo, E.; Cuadrado, C.; Muzquiz, M.

    2016-11-01

    The current European protein deficit is estimated as high as 70% of present needs. Because of the high protein content of their seeds, grain legumes are attractive candidates for lowering the deficiency in plant protein production. The objective of this work was to identify new sources of vegetable protein that would reduce our high dependence of soy, the main source of protein in the manufacture of feedstuffs. To achieve this goal, we determined the proximate composition, the bioactive components, as well as the antinutritional factors present in the studied seeds. In general, the protein, fat and carbohydrates content of legume seeds studied were within the limits found in the literature. The bioactive compounds detected in all the seeds were α-galactosides, myoinositol phosphates, protease inhibitors and phenols. IP6 (phytic acid) was the main inositol phosphate form in all the samples. The highest protease inhibitors content was detected in both Lathyrus cicera cultivars. Vicia ervilia and L. cicera cultivars showed low haemagglutinating activity (20.4 HU/g). The γ-glutamyl-S-ethenyl-cysteine content in Vicia narbonensis was around 16.0 mg/g. Both L. cicera varieties presented similar β-N-oxalyl-L-α, β-diaminopropionic acid content (0.80 mg/g). The two V. ervilia varieties showed high canavanine concentration (1.93-5.28 mg/g). Vicine was only detected in V. narbonensis cultivars (0.3 mg/g). The biochemical characterization carried out in this study allows us to know the limits of inclusion of these minor crop seeds in feed formulations in order to replace the soybean. (Author)

  19. INDEKS GLISEMIK KACANG-KACANGAN [Glycemic Index of Selected Legumes

    Directory of Open Access Journals (Sweden)

    Y. Marsono 1

    2002-12-01

    Full Text Available Nutritional management for diabetic patients based on selection of low available carbohydrate foods has been criticized because the same availability of carbohydrate in different foods may result in different degree of glycemic response. This management is now being corrected by additional aid in selecting foods with the glycemic index (GI of foods. GI is a measure of the glycemic response to the carbohydrate component within a food relative to the response to an equal carbohydrate portion of reference food (glucose or white bread. In Indonesia, data of the glycemic index of foods is still very limited. The objectives of the research are to provide GI of selected legumes, including red bean (Vigna umbellata, Mung bean (Phaseolus aureus, cow pea (Vigna sinensis ENDL, pigeon pea (Cajanus cajan MILLSPAUGH, edible podded peas (Pisum sativum LINN and soy bean (Glycine max MERR. Eleventh health and normal volunteers (not diabetic were provided. The volunteers took an overnight fasting, blood were drawn in the morning and analyzed for serum glucose. Then they were given the test legumes containing total carbohydrates equivalent to 25-g glucose to be consumed. Blood samples were drawn for glucose measurement every 30 minutes until 120 min after meal. Serum glucose was determined enzymatically and the glucose responses were drawn graphically. The GI of the beans studied was lowest for red bean (26 and highest for mung bean (76, Edible podded pea and soy bean had similar value of GI i.e. 30 and 31; whereas pigeon and cow pea had a higher value i.e. 35 and 51, respectively.

  20. Biochemical characterization of legume seeds as ingredients in animal feed

    Directory of Open Access Journals (Sweden)

    Mercedes Martín-Pedrosa

    2016-03-01

    Full Text Available The current European protein deficit is estimated as high as 70% of present needs. Because of the high protein content of their seeds, grain legumes are attractive candidates for lowering the deficiency in plant protein production. The objective of this work was to identify new sources of vegetable protein that would reduce our high dependence of soy, the main source of protein in the manufacture of feedstuffs. To achieve this goal, we determined the proximate composition, the bioactive components, as well as the antinutritional factors present in the studied seeds. In general, the protein, fat and carbohydrates content of legume seeds studied were within the limits found in the literature. The bioactive compounds detected in all the seeds were α-galactosides, myoinositol phosphates, protease inhibitors and phenols. IP6 (phytic acid was the main inositol phosphate form in all the samples. The highest protease inhibitors content was detected in both Lathyrus cicera cultivars. Vicia ervilia and L. cicera cultivars showed low haemagglutinating activity (20.4 HU/g. The γ-glutamyl-S-ethenyl-cysteine content in Vicia narbonensis was around 16.0 mg/g. Both L. cicera varieties presented similar β-N-oxalyl-L-α, β-diaminopropionic acid content (0.80 mg/g. The two V. ervilia varieties showed high canavanine concentration (1.93-5.28 mg/g. Vicine was only detected in V. narbonensis cultivars (0.3 mg/g. The biochemical characterization carried out in this study allows us to know the limits of inclusion of these minor crop seeds in feed formulations in order to replace the soybean.

  1. TRUNCATULIX – a data warehouse for the legume community

    Directory of Open Access Journals (Sweden)

    Runte Kai J

    2009-02-01

    Full Text Available Abstract Background Databases for either sequence, annotation, or microarray experiments data are extremely beneficial to the research community, as they centrally gather information from experiments performed by different scientists. However, data from different sources develop their full capacities only when combined. The idea of a data warehouse directly adresses this problem and solves it by integrating all required data into one single database – hence there are already many data warehouses available to genetics. For the model legume Medicago truncatula, there is currently no such single data warehouse that integrates all freely available gene sequences, the corresponding gene expression data, and annotation information. Thus, we created the data warehouse TRUNCATULIX, an integrative database of Medicago truncatula sequence and expression data. Results The TRUNCATULIX data warehouse integrates five public databases for gene sequences, and gene annotations, as well as a database for microarray expression data covering raw data, normalized datasets, and complete expression profiling experiments. It can be accessed via an AJAX-based web interface using a standard web browser. For the first time, users can now quickly search for specific genes and gene expression data in a huge database based on high-quality annotations. The results can be exported as Excel, HTML, or as csv files for further usage. Conclusion The integration of sequence, annotation, and gene expression data from several Medicago truncatula databases in TRUNCATULIX provides the legume community with access to data and data mining capability not previously available. TRUNCATULIX is freely available at http://www.cebitec.uni-bielefeld.de/truncatulix/.

  2. Classical and molecular genetics of the model legume Lotus japonicus.

    Science.gov (United States)

    Jiang, Q; Gresshoff, P M

    1997-01-01

    The model legume Lotus japonicus was demonstrated to be amenable to classical and molecular genetic analysis, providing the basis for the genetic dissection of the plant processes underlying nodulation and nitrogen fixation. We have developed an efficient method for the sexual hybridization of L. japonicus and obtained F1 progeny derived from a cross of L. japonicus B-129-S9 Gifu x B-581 Funakura. Over half of the cross-pollinations resulted in fertile hybrid seed, which were confirmed morphologically and by single arbitrary primer DNA amplification polymorphisms using the DAF technique. Molecular and morphological markers segregated in true Mendelian fashion in a F2 population of 100 plants. Several DAF loci were linked using the MAPMAKER software to create the first molecular linkage groups of this model legume. The mapping population was advanced to generate a set of immortal recombinant inbred lines (F6; RILs), useful for sharing plant material fixed genetically at most genomic regions. Morphological loci for waved stem shape (Ssh), dark leaf color (Lco), and short flowering period (Fpe) were inherited as single dominant Mendelian loci. DAF markers were dominant and were detected between Gifu and Funakura at about one per primer, suggesting that the parents are closely related. One polymorphism (270G generated by single octomer primer 8.6m) was linked to a morphological locus controlling leaf coloration. The results demonstrate that (i) Lotus japonicus is amenable to diploid genetic analysis, (ii) morphological and molecular markers segregate in true diploid fashion, (iii) molecular polymorphisms can be obtained at a reasonable frequency between the related Gifu and Funakura lines, and iv) the possibility exists for map-based cloning, marker assisted selection and mapping of symbiotic mutations through a genetic and molecular map.

  3. Effects, tolerance mechanisms and management of salt stress in grain legumes.

    Science.gov (United States)

    Farooq, Muhammad; Gogoi, Nirmali; Hussain, Mubshar; Barthakur, Sharmistha; Paul, Sreyashi; Bharadwaj, Nandita; Migdadi, Hussein M; Alghamdi, Salem S; Siddique, Kadambot H M

    2017-09-01

    Salt stress is an ever-present threat to crop yields, especially in countries with irrigated agriculture. Efforts to improve salt tolerance in crop plants are vital for sustainable crop production on marginal lands to ensure future food supplies. Grain legumes are a fascinating group of plants due to their high grain protein contents and ability to fix biological nitrogen. However, the accumulation of excessive salts in soil and the use of saline groundwater are threatening legume production worldwide. Salt stress disturbs photosynthesis and hormonal regulation and causes nutritional imbalance, specific ion toxicity and osmotic effects in legumes to reduce grain yield and quality. Understanding the responses of grain legumes to salt stress and the associated tolerance mechanisms, as well as assessing management options, may help in the development of strategies to improve the performance of grain legumes under salt stress. In this manuscript, we discuss the effects, tolerance mechanisms and management of salt stress in grain legumes. The principal inferences of the review are: (i) salt stress reduces seed germination (by up to more than 50%) either by inhibiting water uptake and/or the toxic effect of ions in the embryo, (ii) salt stress reduces growth (by more than 70%), mineral uptake, and yield (by 12-100%) due to ion toxicity and reduced photosynthesis, (iii) apoplastic acidification is a good indicator of salt stress tolerance, (iv) tolerance to salt stress in grain legumes may develop through excretion and/or compartmentalization of toxic ions, increased antioxidant capacity, accumulation of compatible osmolytes, and/or hormonal regulation, (v) seed priming and nutrient management may improve salt tolerance in grain legumes, (vi) plant growth promoting rhizobacteria and arbuscular mycorrhizal fungi may help to improve salt tolerance due to better plant nutrient availability, and (vii) the integration of screening, innovative breeding, and the development of

  4. Effect of mycorrhiza symbiosis on the Nacl salinity in Sorghum bicolor

    African Journals Online (AJOL)

    Jane

    2011-08-01

    Aug 1, 2011 ... Effect of mycorrhiza symbiosis on the Nacl salinity in. Sorghum bicolor. Ghanbar Laei*, M. H. Khajehzadeh, Hossein Afshari, Abdol Ghaffar Ebadi and Hossein. Abbaspour. Department of Agricultural Sciences, Damghan branch, Islamic Azad University, Damghan, Iran. Accepted 19 May, 2011. In order to ...

  5. Effect of mycorrhiza symbiosis on the Nacl salinity in Sorghum bicolor

    African Journals Online (AJOL)

    In order to determine mycorrhizal symbiosis on the Nacl salinity tolerance in Sorghum bicolor (aspydfyd cultivar), an experiment with two factors was done in Damghan Islamic Azad University laboratory (Iran) in 2007. The first factor with two levels (mycorihizal and non-mycorihizal) and second factor with six levels Nacl ...

  6. A case study of industrial symbiosis. Nanning Sugar Co., Ltd. in China

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Shanlin; Feng, Nanping [Management School of Hefei University of Technology, 270 Mail Box, Hefei, Anhui Province 230009 (China)

    2008-03-15

    Industrial symbiosis activities are being implemented in the philosophy of 'circular economy' in China. Integrating industrial symbiosis into the corporate development plans to optimize materials and energy flows is a feasible strategy for many corporations in their transition between nonsustainable and sustainable development. By constructing industrial ecosystems, Nanning Sugar Co., Ltd. in China, has achieved the successful transition from a traditional corporation to a sustainable corporation, or rather, a circular corporation. This study expounds on its whole transition course to a circular complex in the past decade, in which four factors are essential to making this symbiosis achievable: rational production structures; raw materials advantages; technical supports and correct diversification. The corporation is in charge of almost all the aspects of its affiliated companies and the management mode, in particular, differing from that of industrial symbiosis systems in Kalundborg, is considered another potential factor contributing to the corporate success. The transition mode in question is hoped to point to a feasible development path for similar corporations. (author)

  7. Bacterial leaf symbiosis in angiosperms: host specificity without co-speciation.

    Directory of Open Access Journals (Sweden)

    Benny Lemaire

    Full Text Available Bacterial leaf symbiosis is a unique and intimate interaction between bacteria and flowering plants, in which endosymbionts are organized in specialized leaf structures. Previously, bacterial leaf symbiosis has been described as a cyclic and obligate interaction in which the endosymbionts are vertically transmitted between plant generations and lack autonomous growth. Theoretically this allows for co-speciation between leaf nodulated plants and their endosymbionts. We sequenced the nodulated Burkholderia endosymbionts of 54 plant species from known leaf nodulated angiosperm genera, i.e. Ardisia, Pavetta, Psychotria and Sericanthe. Phylogenetic reconstruction of bacterial leaf symbionts and closely related free-living bacteria indicates the occurrence of multiple horizontal transfers of bacteria from the environment to leaf nodulated plant species. This rejects the hypothesis of a long co-speciation process between the bacterial endosymbionts and their host plants. Our results indicate a recent evolutionary process towards a stable and host specific interaction confirming the proposed maternal transmission mode of the endosymbionts through the seeds. Divergence estimates provide evidence for a relatively recent origin of bacterial leaf symbiosis, dating back to the Miocene (5-23 Mya. This geological epoch was characterized by cool and arid conditions, which may have triggered the origin of bacterial leaf symbiosis.

  8. Dynamics of arbuscular mycorrhizal symbiosis in heavy metal phytoremediation: Meta-analytical and conceptual perspectives

    International Nuclear Information System (INIS)

    Audet, Patrick; Charest, Christiane

    2007-01-01

    To estimate dynamics of arbuscular mycorrhizal (AM) symbiosis in heavy metal (HM) phytoremediation, we conducted a literature survey and correlated HM uptake and relative plant growth parameters from published data. After estimating AM feedback responses for these parameters at low and high soil-HM concentration intervals, we determined that the roles of AM symbiosis are characterized by (1) an increased HM phytoextraction via mycorrhizospheric 'Enhanced Uptake' at low soil-HM concentrations, and (2) a reduced HM bioavailability via AM fungal 'Metal-Binding' processes at high soil-HM levels, hence resulting in increased plant biomass and enhanced plant tolerance through HM stress-avoidance. We present two conceptual models which illustrate the important compromise between plant growth, plant HM uptake and HM tolerance, and further emphasize the importance of AM symbiosis in buffering the soil environment for plants under such stress conditions. - This meta-analysis has revealed a transition role of the AM symbiosis in phytoremediation shifting from 'Enhanced Uptake' to 'Metal-Binding' beyond critical soil-HM levels

  9. A nodule-specific protein secretory pathway required for nitrogen-fixing symbiosis

    NARCIS (Netherlands)

    Wang, D.; Griffitts, J.; Starker, C.; Fedorova, E.; Limpens, E.H.M.; Ivanov, S.E.; Bisseling, T.; Long, S.

    2010-01-01

    The nitrogen-fixing symbiosis between Sinorhizobium meliloti and its leguminous host plant Medicago truncatula occurs in a specialized root organ called the nodule. Bacteria that are released into plant cells are surrounded by a unique plant membrane compartment termed a symbiosome. We found that in

  10. Impacts of domestication on the arbuscular mycorrhizal symbiosis of 27 crop species.

    Science.gov (United States)

    Martín-Robles, Nieves; Lehmann, Anika; Seco, Erica; Aroca, Ricardo; Rillig, Matthias C; Milla, Rubén

    2018-04-01

    The arbuscular mycorrhizal (AM) symbiosis is key to plant nutrition, and hence is potentially key in sustainable agriculture. Fertilization and other agricultural practices reduce soil AM fungi and root colonization. Such conditions might promote the evolution of low mycorrhizal responsive crops. Therefore, we ask if and how evolution under domestication has altered AM symbioses of crops. We measured the effect of domestication on mycorrhizal responsiveness across 27 crop species and their wild progenitors. Additionally, in a subset of 14 crops, we tested if domestication effects differed under contrasting phosphorus (P) availabilities. The response of AM symbiosis to domestication varied with P availability. On average, wild progenitors benefited from the AM symbiosis irrespective of P availability, while domesticated crops only profited under P-limited conditions. Magnitudes and directions of response were diverse among the 27 crops, and were unrelated to phylogenetic affinities or to the coordinated evolution with fine root traits. Our results indicate disruptions in the efficiency of the AM symbiosis linked to domestication. Under high fertilization, domestication could have altered the regulation of resource trafficking between AM fungi and associated plant hosts. Provided that crops are commonly raised under high fertilization, this result has important implications for sustainable agriculture. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  11. A Literature Survey of Information Systems Facilitating the Identification of Industrial Symbiosis

    NARCIS (Netherlands)

    van Capelleveen, Guido Cornelis; Amrit, Chintan Amrit; Yazan, Devrim Murat; Otjacques, Benoit; Hitzelberger, Patrik; Naumann, Stefan; Wohlgemuth, Volker

    2017-01-01

    Industrial Symbiosis (IS) is an emerging business tool that is used by practitioners to engage cooperation among industries to reuse waste streams. The key to reveal IS opportunities for organizations is both connecting the supply and demand of various industries and providing technical knowledge on

  12. The Mutual Symbiosis between Inclusive Bi-Lingual Education and Multicultural Education

    Science.gov (United States)

    Irby, Beverly J.; Tong, Fuhui; Lara-Alecio, Rafael

    2011-01-01

    In this article the authors postulate a mutual symbiosis between multicultural and inclusive bi-lingual education. Combining bi-lingual and multicultural education to create a symbiotic relationship can stimulate reform in schools and can promote inclusive educational systems, thereby keeping native languages and cultures alive for minority…

  13. The promiscuous larvae: flexibility in the establishment of symbiosis in corals

    Science.gov (United States)

    Cumbo, V. R.; Baird, A. H.; van Oppen, M. J. H.

    2013-03-01

    Coral reefs thrive in part because of the symbiotic partnership between corals and Symbiodinium. While this partnership is one of the keys to the success of coral reef ecosystems, surprisingly little is known about many aspects of coral symbiosis, in particular the establishment and development of symbiosis in host species that acquire symbionts anew in each generation. More specifically, the point at which symbiosis is established (i.e., larva vs. juvenile) remains uncertain, as does the source of free-living Symbiodinium in the environment. In addition, the capacity of host and symbiont to form novel combinations is unknown. To explore patterns of initial association between host and symbiont, larvae of two species of Acropora were exposed to sediment collected from three locations on the Great Barrier Reef. A high proportion of larvae established symbiosis shortly after contact with sediments, and Acropora larvae were promiscuous, taking up multiple types of Symbiodinium. The Symbiodinium types acquired from the sediments reflected the symbiont assemblage within a wide range of cnidarian hosts at each of the three sites, suggesting potential regional differences in the free-living Symbiodinium assemblage. Coral larvae clearly have the capacity to take up Symbiodinium prior to settlement, and sediment is a likely source. Promiscuous larvae allow species to associate with Symbiodinium appropriate for potentially novel environments that may be experienced following dispersal.

  14. Arbuscular mycorrhizal symbiosis and methyl jasmonate avoid the inhibition of root hydraulic conductivity caused by drought.

    Science.gov (United States)

    Sánchez-Romera, Beatriz; Ruiz-Lozano, Juan Manuel; Zamarreño, Ángel María; García-Mina, José María; Aroca, Ricardo

    2016-02-01

    Hormonal regulation and symbiotic relationships provide benefits for plants to overcome stress conditions. The aim of this study was to elucidate the effects of exogenous methyl jasmonate (MeJA) application on root hydraulic conductivity (L) of Phaseolus vulgaris plants which established arbuscular mycorrhizal (AM) symbiosis under two water regimes (well-watered and drought conditions). The variation in endogenous contents of several hormones (MeJA, JA, abscisic acid (ABA), indol-3-acetic acid (IAA), salicylic acid (SA)) and the changes in aquaporin gene expression, protein abundance and phosphorylation state were analyzed. AM symbiosis decreased L under well-watered conditions, which was partially reverted by the MeJA treatment, apparently by a drop in root IAA contents. Also, AM symbiosis and MeJA prevented inhibition of L under drought conditions, most probably by a reduction in root SA contents. Additionally, the gene expression of two fungal aquaporins was upregulated under drought conditions, independently of the MeJA treatment. Plant aquaporin gene expression could not explain the behaviour of L. Conversely, evidence was found for the control of L by phosphorylation of aquaporins. Hence, MeJA addition modified the response of L to both AM symbiosis and drought, presumably by regulating the root contents of IAA and SA and the phosphorylation state of aquaporins.

  15. Insights on the Impact of Arbuscular Mycorrhizal Symbiosis on Tomato Tolerance to Water Stress1[OPEN

    Science.gov (United States)

    Siciliano, Ilenia

    2016-01-01

    Arbuscular mycorrhizal (AM) fungi, which form symbioses with the roots of the most important crop species, are usually considered biofertilizers, whose exploitation could represent a promising avenue for the development in the future of a more sustainable next-generation agriculture. The best understood function in symbiosis is an improvement in plant mineral nutrient acquisition, as exchange for carbon compounds derived from the photosynthetic process: this can enhance host growth and tolerance to environmental stresses, such as water stress (WS). However, physiological and molecular mechanisms occurring in arbuscular mycorrhiza-colonized plants and directly involved in the mitigation of WS effects need to be further investigated. The main goal of this work is to verify the potential impact of AM symbiosis on the plant response to WS. To this aim, the effect of two AM fungi (Funneliformis mosseae and Rhizophagus intraradices) on tomato (Solanum lycopersicum) under the WS condition was studied. A combined approach, involving ecophysiological, morphometric, biochemical, and molecular analyses, has been used to highlight the mechanisms involved in plant response to WS during AM symbiosis. Gene expression analyses focused on a set of target genes putatively involved in the plant response to drought, and in parallel, we considered the expression changes induced by the imposed stress on a group of fungal genes playing a key role in the water-transport process. Taken together, the results show that AM symbiosis positively affects the tolerance to WS in tomato, with a different plant response depending on the AM fungi species involved. PMID:27208301

  16. Laser-ablation electrospray ionization mass spectrometry with ion mobility separation reveals metabolites in the symbiotic interactions of soybean roots and rhizobia

    Energy Technology Data Exchange (ETDEWEB)

    Stopka, Sylwia A.; Agtuca, Beverly J.; Koppenaal, David W.; Pasa Tolic, Ljiljana; Stacey, Gary; Vertes, Akos; Anderton, Christopher R.

    2017-05-23

    Technologies enabling in situ metabolic profiling of living plant systems are invaluable for understanding physiological processes and could be used for rapid phenotypic screening (e.g., to produce plants with superior biological nitrogen fixing ability). The symbiotic interaction between legumes and nitrogen-fixing soil bacteria results in a specialized plant organ (i.e., root nodule), where the exchange of nutrients between host and endosymbiont occurs. Laser ablation electrospray ionization mass spectrometry (LAESI-MS) is a method that can be performed under ambient conditions requiring minimal sample preparation. Here, we employed LAESI-MS to explore the well-characterized symbiosis between soybean (Glycine max L. Merr.) and its compatible symbiont, Bradyrhizobium japonicum. The utilization of ion mobility separation (IMS) improved the molecular coverage, selectivity, and identification of the detected biomolecules. Specifically, incorporation of IMS resulted in an increase of 153 detected metabolites in the nodule samples. The data presented demonstrates the advantages of using LAESI-IMS-MS for the rapid analysis of intact root nodules, uninfected root segments, and free-living rhizobia. Untargeted pathway analysis revealed several metabolic processes within the nodule (e.g., zeatin, riboflavin, and purine synthesis). Compounds specific to the uninfected root and bacteria were also detected. Lastly, we performed depth-profiling of intact nodules to reveal the location of metabolites to the cortex and inside the infected region, and lateral profiling of sectioned nodules confirmed these molecular distributions. Our results established the feasibility of LAESI-IMS-MS for the analysis and spatial mapping of plant tissues, with its specific demonstration to improve our understanding of the soybean-rhizobial symbiosis.

  17. Possible Role of 1-Aminocyclopropane-1-Carboxylate (ACC) Deaminase Activity of Sinorhizobium sp. BL3 on Symbiosis with Mung Bean and Determinate Nodule Senescence

    Science.gov (United States)

    Tittabutr, Panlada; Sripakdi, Sudarat; Boonkerd, Nantakorn; Tanthanuch, Waraporn; Minamisawa, Kiwamu; Teaumroong, Neung

    2015-01-01

    Sinorhizobium sp. BL3 forms symbiotic interactions with mung bean (Vigna radiata) and contains lrpL-acdS genes, which encode the 1-aminocyclopropane-1-carboxylate (ACC) deaminase enzyme that cleaves ACC, a precursor of plant ethylene synthesis. Since ethylene interferes with nodule formation in some legumes and plays a role in senescence in plant cells, BL3-enhancing ACC deaminase activity (BL3+) and defective mutant (BL3−) strains were constructed in order to investigate the effects of this enzyme on symbiosis and nodule senescence. Nodulation competitiveness was weaker in BL3− than in the wild-type, but was stronger in BL3+. The inoculation of BL3− into mung bean resulted in less plant growth, a lower nodule dry weight, and smaller nodule number than those in the wild-type, whereas the inoculation of BL3+ had no marked effects. However, similar nitrogenase activity was observed with all treatments; it was strongly detected 3 weeks after the inoculation and gradually declined with time, indicating senescence. The rate of plant nodulation by BL3+ increased in a time-dependent manner. Nodules occupied by BL3− formed smaller symbiosomes, and bacteroid degradation was more prominent than that in the wild-type 7 weeks after the inoculation. Changes in biochemical molecules during nodulation were tracked by Fourier Transform Infrared (FT-IR) microspectroscopy, and the results obtained confirmed that aging processes differed in nodules occupied by BL3 and BL3−. This is the first study to show the possible role of ACC deaminase activity in senescence in determinate nodules. Our results suggest that an increase in ACC deaminase activity in this strain does not extend the lifespan of nodules, whereas the lack of this activity may accelerate nodule senescence. PMID:26657304

  18. Turnover of grain legume N rhizodeposits and effect of rhizodeposition on the turnover of crop residues

    DEFF Research Database (Denmark)

    Mayer, J.; Buegger, F.; Jensen, E.S.

    2004-01-01

    C). A sandy loam soil for the experiment was either stored at 6 degreesC or planted with the respective grain legume in pots. Legumes were in situ N-15 stem labelled during growth and visible roots were removed at maturity. The remaining plant-derived N in soil was defined as N rhizodeposition....... In the experiment the turnover of C and N was compared in soils with and without previous growth of three legumes and with and without incorporation of crop residues. After 168 days, 21% (lupin), 26% (faba bean) and 27% (pea) of rhizodeposition N was mineralised in the treatments without crop residues. A smaller...

  19. Comparisonof physicochemical properties of selected locally available legume varieties (mung bean, cowpea and soybean)

    OpenAIRE

    Kulasooriyage Tharuka Gunathilake; Theja Herath; Jagath Wansapala

    2016-01-01

    Grain legumes are widely used as high-protein contained crops that play a secondary role to cereal or root crops. In Sri Lanka various legume species are cultivated and often utilised in the whole grain boiled form. The objective of present study was to analyse and compare locally grown legumes varieties; Mung bean (MI 5, MI 6), Cowpea (Bombay, Waruni, Dhawal, MICP1, ANKCP1) and soybean (pb1, MISB1) for their morphological characteristics, proximate and mineral composition (Fe, Ca, Zn, K, P)....

  20. Genetic resources in the USDA, ARS, PGRCU legume crop germplasm collections with phyto-pharmaceutical uses

    Science.gov (United States)

    Seventeen health functional legumes including butterfly pea (Clitoria ternatea L.), Indigofera cassioides Rottler ex DC., I. linnaei Ali, I. suffruticosa Mill., hyacinth bean [Lablab purpureus (L.) Sweet], velvetbean [Mucuna pruriens (L.) DC], jicama [Pachyrhizus erosus (L.) Urb.], winged bean [Psop...