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Sample records for legume endosymbiont sinorhizobium

  1. Vigna unguiculata is nodulated in Spain by endosymbionts of Genisteae legumes and by a new symbiovar (vignae) of the genus Bradyrhizobium.

    Science.gov (United States)

    Bejarano, Ana; Ramírez-Bahena, Martha-Helena; Velázquez, Encarna; Peix, Alvaro

    2014-10-01

    Vigna unguiculata was introduced into Europe from its distribution centre in Africa, and it is currently being cultivated in Mediterranean regions with adequate edapho-climatic conditions where the slow growing rhizobia nodulating this legume have not yet been studied. Previous studies based on rrs gene and ITS region analyses have shown that Bradyrhizobium yuanmingense and B. elkanii nodulated V. unguiculata in Africa, but these two species were not found in this study. Using the same phylogenetic markers it was shown that V. unguiculata, a legume from the tribe Phaseolae, was nodulated in Spain by two species of group I, B. cytisi and B. canariense, which are common endosymbionts of Genisteae in both Europe and Africa. These species have not been found to date in V. unguiculata nodules in its African distribution centres. All strains from Bradyrhizobium group I isolated in Spain belonged to the symbiovar genistearum, which is found at present only in Genisteae legumes in both Africa and Europe. V. unguiculata was also nodulated in Spain by a strain from Bradyrhizobium group II that belonged to a novel symbiovar (vignae). Some African V. unguiculata-nodulating strains also belonged to this proposed new symbiovar. Copyright © 2014 Elsevier GmbH. All rights reserved.

  2. A consolidated analysis of the physiologic and molecular responses induced under acid stress in the legume-symbiont model-soil bacterium Sinorhizobium meliloti.

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    Draghi, W O; Del Papa, M F; Hellweg, C; Watt, S A; Watt, T F; Barsch, A; Lozano, M J; Lagares, A; Salas, M E; López, J L; Albicoro, F J; Nilsson, J F; Torres Tejerizo, G A; Luna, M F; Pistorio, M; Boiardi, J L; Pühler, A; Weidner, S; Niehaus, K; Lagares, A

    2016-07-11

    Abiotic stresses in general and extracellular acidity in particular disturb and limit nitrogen-fixing symbioses between rhizobia and their host legumes. Except for valuable molecular-biological studies on different rhizobia, no consolidated models have been formulated to describe the central physiologic changes that occur in acid-stressed bacteria. We present here an integrated analysis entailing the main cultural, metabolic, and molecular responses of the model bacterium Sinorhizobium meliloti growing under controlled acid stress in a chemostat. A stepwise extracellular acidification of the culture medium had indicated that S. meliloti stopped growing at ca. pH 6.0-6.1. Under such stress the rhizobia increased the O2 consumption per cell by more than 5-fold. This phenotype, together with an increase in the transcripts for several membrane cytochromes, entails a higher aerobic-respiration rate in the acid-stressed rhizobia. Multivariate analysis of global metabolome data served to unequivocally correlate specific-metabolite profiles with the extracellular pH, showing that at low pH the pentose-phosphate pathway exhibited increases in several transcripts, enzymes, and metabolites. Further analyses should be focused on the time course of the observed changes, its associated intracellular signaling, and on the comparison with the changes that operate during the sub lethal acid-adaptive response (ATR) in rhizobia.

  3. 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 ...

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

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    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…

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

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    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.

  6. 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...

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

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    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.

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

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    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.

  9. Biogeography of Sinorhizobium meliloti nodulating alfalfa in different Croatian regions.

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    Donnarumma, Francesca; Bazzicalupo, Marco; Blažinkov, Mihaela; Mengoni, Alessio; Sikora, Sanjia; Babić, Katarina Huić

    2014-09-01

    Sinorhizobium meliloti is a nitrogen-fixing rhizobium symbiont of legumes, widespread in many temperate environments the high genetic diversity of which enables it to thrive as a symbiont of host legumes and free-living in soil. Soil type, together with geographic differences and host plant genotype, seem to be prominent factors in shaping rhizobial genetic diversity. While a large body of research supports the idea that the genetic structure of free-living microbial taxa exhibits a clear biogeographic pattern, few investigations have been performed on the biogeographic pattern of S. meliloti genotypes in a restricted geographic range. In the present study, a collection of 128 S. meliloti isolates from three different regions in Croatia was investigated to analyze the relationship between genetic diversity, geographic distribution, soil features and isolate phenotypes by using amplified fragment length polymorphism (AFLP) as a genome-wide scanning method. Results obtained led to the conclusion that the genotypes of isolates cluster according to the region of origin and that the differentiation of S. meliloti populations can be mainly ascribed to geographic isolation following an isolation-by-distance model, with a strong distance-decay relationship of genetic similarity with distance, in which local soil conditions are not the major component influencing the isolate phenotypes or their genomic differentiation. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  10. Sinorhizobium meliloti YbeY is an endoribonuclease with unprecedented catalytic features, acting as silencing enzyme in riboregulation

    OpenAIRE

    Saramago, Margarida; Peregrina, Alexandra; Robledo, Marta; Matos, Rute G.; Hilker, Rolf; Serrania, Javier; Becker, Anke; Arraiano, Cecilia M.; Jim?nez-Zurdo, Jos? I.

    2016-01-01

    Abstract Structural and biochemical features suggest that the almost ubiquitous bacterial YbeY protein may serve catalytic and/or Hfq-like protective functions central to small RNA (sRNA)-mediated regulation and RNA metabolism. We have biochemically and genetically characterized the YbeY ortholog of the legume symbiont Sinorhizobium meliloti (SmYbeY). Co-immunoprecipitation (CoIP) with a FLAG-tagged SmYbeY yielded a poor enrichment in RNA species, compared to Hfq CoIP-RNA uncovered previously...

  11. Toxic effects of arsenic on Sinorhizobium-Medicago sativa symbiotic interaction.

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    Pajuelo, Eloísa; Rodríguez-Llorente, Ignacio D; Dary, Mohammed; Palomares, Antonio J

    2008-07-01

    Recently, the Rhizobium-legume symbiotic interaction has been proposed as an interesting tool in bioremediation. However, little is known about the effect of most common contaminants on this process. The phytotoxic effects of arsenic on nodulation of Medicago sativa have been examined in vitro using the highly arsenic resistant and symbiotically effective Sinorhizobium sp. strain MA11. The bacteria were able to grow on plates containing As concentrations as high as 10 mM. Nevertheless, as little as 25-35 microM arsenite produced a 75% decrease in the total number of nodules, due to a 90% reduction in the number of rhizobial infections, as could be determined using the strain MA11 carrying a lacZ reporter gene. This effect was associated to root hair damage and a shorter infective root zone. However, once nodulation was established nodule development seemed to continue normally, although earlier senescence could be observed in nodules of arsenic-grown plants.

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

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    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.

  13. Molecular diagnosis of Wolbachia endosymbiont from Iranian ...

    African Journals Online (AJOL)

    ... Wolbachia 16S rDNA gene. PCR product was directly sequenced and the alignment of the sequence with similar sequences in GenBank showed high similarity with 16S rDNA gene of Wolbachia endosymbiont of Drosophila melanogaster. Key words: Wolbachia, Iranian scorpion, 16S rDNA gene, Hemiscorpius lepturus.

  14. Genetic Identification and Symbiotic Efficiency of an Indigenous Sinorhizobium meliloti Field Population

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    Sanja Sikora

    2003-01-01

    Full Text Available Soil bacteria Sinorhizobium meliloti are of enormous agricultural value, because of their ability to fix atmospheric nitrogen in symbiosis with an important forage crop legume – alfalfa. The main aim of this study was (i to isolate indigenous S. meliloti strains from different field sites in Croatia, (ii to assess genetic diversity and genetic relationships amongst strains of natural populations and (iii to provide information about nodulation and symbiotic efficiency of indigenous S. meliloti strains. The nine strains isolated from alfalfa nodules collected from different field sites and three reference strains were analysed. Genetic characterisation by PCR-RFLP of the 16S rDNA, rep-PCR and RAPD-PCR was applied to study the status of Sinorhizobium meliloti populations inhabiting nodules of alfalfa. The results of PCR-RFLP of the 16S rDNA revealed that all isolates belong to the S. meliloti species. Cluster analysis of rep-PCR and RAPD-PCR profiles showed significant differences among S. meliloti isolates. Both methods resulted in identical grouping of strains. Among indigenous strains two divergent groups could be determined. The biggest differences were detected among two reference strains and all field isolates. Greenhouse studies were performed for evaluation of symbiotic efficiency and compatibility of S. meliloti strains with two alfalfa cultivars. Quantitative expression of symbiotic efficiency was evaluated by measurement of nodule dry weight, content of proteins and total nitrogen in plants, dry matter and green mass yield of plants. All strains nodulated both alfalfa cultivars but with different efficiency. Significant differences in dry matter and green mass yield of alfalfa as well as protein content were determined depending on the strain used. The results indicate that three indigenous S. meliloti strains can be characterised as the most efficient of all strains used in this study.

  15. A Transposable Partitioning Locus Used To Stabilize Plasmid-Borne Hydrogen Oxidation and Trifolitoxin Production Genes in a Sinorhizobium Strain

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    Kent, Angela D.; Wojtasiak, Michelle L.; Robleto, Eduardo A.; Triplett, Eric W.

    1998-01-01

    Improved nitrogen-fixing inoculum strains for leguminous crops must be able to effectively compete with indigenous strains for nodulation, enhance legume productivity compared to the productivity obtained with indigenous strains, and maintain stable expression of any added genes in the absence of selection pressure. We constructed a transposable element containing the tfx region for expression of increased nodulation competitiveness and the par locus for plasmid stability. The transposon was inserted into tetA of pHU52, a broad-host-range plasmid conferring the H2 uptake phenotype. The resulting plasmid, pHUTFXPAR, conferred the plasmid stability, trifolitoxin production, and H2 uptake phenotypes in the broad-host-range organism Sinorhizobium sp. strain ANU280. The broad applications of a transposon conferring plasmid stability are discussed. PMID:9572932

  16. pSymA-Dependent Mobilization of the Sinorhizobium meliloti pSymB Megaplasmid ▿ †

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    Blanca-Ordóñez, Helena; Oliva-García, Juan J.; Pérez-Mendoza, Daniel; Soto, María J.; Olivares, José; Sanjuán, Juan; Nogales, Joaquina

    2010-01-01

    Sinorhizobium meliloti 1021 carries two megaplasmids, pSymA of 1,354 kb and pSymB of 1,683 kb, which are essential in establishing symbiosis with its legume hosts and important for bacterial fitness in the rhizosphere. We have previously shown that pSymA is self-transmissible and that its conjugal functions are regulated by the transcriptional repressor RctA. Here, we show conjugal transfer of pSymB as an in trans mobilization event that requires the type IV secretion system encoded by pSymA. pSymB carries a functional oriT and an adjacent relaxase gene, traA2, that is also transcriptionally repressed by rctA. Both symbiotic megaplasmids would require the relaxase genes in cis with their respective oriTs to achieve the highest transfer efficiencies. PMID:20889746

  17. Sinorhizobium arboris sp. nov. and Sinorhizobium kostiense sp. nov., isolated from leguminous trees in Sudan and Kenya.

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    Nick, G; de Lajudie, P; Eardly, B D; Suomalainen, S; Paulin, L; Zhang, X; Gillis, M; Lindström, K

    1999-10-01

    SDS-PAGE of total bacterial proteins was applied to the classification of 25 Sudanese and five Kenyan strains isolated from the root nodules of Acacia senegal and Prosopis chilensis. Twenty strains were also studied by multilocus enzyme electrophoresis (MLEE) and the whole 16S rRNA gene was sequenced from two strains representing the two major clusters. These results, together with the previously reported numerical taxonomy analysis, pulsed-field gel electrophoresis studies, DNA-DNA dot-blot hybridization, genomic fingerprinting using repetitive sequence-based PCR, DNA base composition analysis, DNA-DNA reassociation analysis, partial sequencing of the 16S rRNA gene and RFLP analysis of the amplified 16S rRNA gene, showed that all 30 strains belong to the genus Sinorhizobium. Two of the strains grouped with Sinorhizobium saheli and seven with Sinorhizobium terangae, while the rest did not cluster with any of the established species. The majority of the strains formed two phenotypically and genotypically distinct groups and we therefore propose that these strains should be classified as two new species, Sinorhizobium arboris sp. nov. and Sinorhizobium kostiense sp. nov.

  18. Molecular diagnosis of Wolbachia endosymbiont from Iranian ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-28

    Dec 28, 2011 ... the biocontrol of insect pests (Ravikumar et al., 2011) and vector-born diseases such as dangue ... dNTP, 0.4 mM of each primer, 1 µl of the crude DNA extract, 1 Mm. MgCl2, 2.5 µl of 10 x PCR buffer, 0.3 U .... protocol to obtain highly pure Wolbachia endosymbiont DNA for genome sequencing. J. Microbiol.

  19. Patterns and mechanisms in instances of endosymbiont-induced parthenogenesis.

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    Ma, W-J; Schwander, T

    2017-05-01

    Female-producing parthenogenesis can be induced by endosymbionts that increase their transmission by manipulating host reproduction. Our literature survey indicates that such endosymbiont-induced parthenogenesis is known or suspected in 124 host species from seven different arthropod taxa, with Wolbachia as the most frequent endosymbiont (in 56-75% of host species). Most host species (81%, 100 out of 124) are characterized by haplo-diploid sex determination, but a strong ascertainment bias likely underestimates the frequency of endosymbiont-induced parthenogenesis in hosts with other sex determination systems. In at least one taxon, hymenopterans, endosymbionts are a significant driver of transitions from sexual to parthenogenetic reproduction, with one-third of lineages being parthenogenetic as a consequence of endosymbiont infection. Endosymbiont-induced parthenogenesis appears to facilitate the maintenance of reproductive polymorphism: at least 50% of species comprise both sexual (uninfected) and parthenogenetic (infected) strains. These strains feature distribution differences similar to the ones documented for lineages with genetically determined parthenogenesis, with endosymbiont-induced parthenogens occurring at higher latitudes than their sexual relatives. Finally, although gamete duplication is often considered as the main mechanism for endosymbiont-induced parthenogenesis, it underlies parthenogenesis in only half of the host species studied thus far. We point out caveats in the methods used to test for endosymbiont-induced parthenogenesis and suggest specific approaches that allow for firm conclusions about the involvement of endosymbionts in the origin of parthenogenesis. © 2017 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.

  20. In silico insights into the symbiotic nitrogen fixation in Sinorhizobium meliloti via metabolic reconstruction.

    Science.gov (United States)

    Zhao, Hansheng; Li, Mao; Fang, Kechi; Chen, Wenfeng; Wang, Jing

    2012-01-01

    Sinorhizobium meliloti is a soil bacterium, known for its capability to establish symbiotic nitrogen fixation (SNF) with leguminous plants such as alfalfa. S. meliloti 1021 is the most extensively studied strain to understand the mechanism of SNF and further to study the legume-microbe interaction. In order to provide insight into the metabolic characteristics underlying the SNF mechanism of S. meliloti 1021, there is an increasing demand to reconstruct a metabolic network for the stage of SNF in S. meliloti 1021. Through an iterative reconstruction process, a metabolic network during the stage of SNF in S. meliloti 1021 was presented, named as iHZ565, which accounts for 565 genes, 503 internal reactions, and 522 metabolites. Subjected to a novelly defined objective function, the in silico predicted flux distribution was highly consistent with the in vivo evidences reported previously, which proves the robustness of the model. Based on the model, refinement of genome annotation of S. meliloti 1021 was performed and 15 genes were re-annotated properly. There were 19.8% (112) of the 565 metabolic genes included in iHZ565 predicted to be essential for efficient SNF in bacteroids under the in silico microaerobic and nutrient sharing condition. As the first metabolic network during the stage of SNF in S. meliloti 1021, the manually curated model iHZ565 provides an overview of the major metabolic properties of the SNF bioprocess in S. meliloti 1021. The predicted SNF-required essential genes will facilitate understanding of the key functions in SNF and help identify key genes and design experiments for further validation. The model iHZ565 can be used as a knowledge-based framework for better understanding the symbiotic relationship between rhizobia and legumes, ultimately, uncovering the mechanism of nitrogen fixation in bacteroids and providing new strategies to efficiently improve biological nitrogen fixation.

  1. High-resolution transcriptomic analyses of Sinorhizobium sp. NGR234 bacteroids in determinate nodules of Vigna unguiculata and indeterminate nodules of Leucaena leucocephala.

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    Li, Yan; Tian, Chang Fu; Chen, Wen Feng; Wang, Lei; Sui, Xin Hua; Chen, Wen Xin

    2013-01-01

    The rhizobium-legume symbiosis is a model system for studying mutualistic interactions between bacteria and eukaryotes. Sinorhizobium sp. NGR234 is distinguished by its ability to form either indeterminate nodules or determinate nodules with diverse legumes. Here, we presented a high-resolution RNA-seq transcriptomic analysis of NGR234 bacteroids in indeterminate nodules of Leucaena leucocephala and determinate nodules of Vigna unguiculata. In contrast to exponentially growing free-living bacteria, non-growing bacteroids from both legumes recruited several common cellular functions such as cbb3 oxidase, thiamine biosynthesis, nitrate reduction pathway (NO-producing), succinate metabolism, PHB (poly-3-hydroxybutyrate) biosynthesis and phosphate/phosphonate transporters. However, different transcription profiles between bacteroids from two legumes were also uncovered for genes involved in the biosynthesis of exopolysaccharides, lipopolysaccharides, T3SS (type three secretion system) and effector proteins, cytochrome bd ubiquinol oxidase, PQQ (pyrroloquinoline quinone), cytochrome c550, pseudoazurin, biotin, phasins and glycolate oxidase, and in the metabolism of glutamate and phenylalanine. Noteworthy were the distinct expression patterns of genes encoding phasins, which are thought to be involved in regulating the surface/volume ratio of PHB granules. These patterns are in good agreement with the observed granule size difference between bacteroids from L. leucocephala and V. unguiculata.

  2. High-resolution transcriptomic analyses of Sinorhizobium sp. NGR234 bacteroids in determinate nodules of Vigna unguiculata and indeterminate nodules of Leucaena leucocephala.

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    Yan Li

    Full Text Available The rhizobium-legume symbiosis is a model system for studying mutualistic interactions between bacteria and eukaryotes. Sinorhizobium sp. NGR234 is distinguished by its ability to form either indeterminate nodules or determinate nodules with diverse legumes. Here, we presented a high-resolution RNA-seq transcriptomic analysis of NGR234 bacteroids in indeterminate nodules of Leucaena leucocephala and determinate nodules of Vigna unguiculata. In contrast to exponentially growing free-living bacteria, non-growing bacteroids from both legumes recruited several common cellular functions such as cbb3 oxidase, thiamine biosynthesis, nitrate reduction pathway (NO-producing, succinate metabolism, PHB (poly-3-hydroxybutyrate biosynthesis and phosphate/phosphonate transporters. However, different transcription profiles between bacteroids from two legumes were also uncovered for genes involved in the biosynthesis of exopolysaccharides, lipopolysaccharides, T3SS (type three secretion system and effector proteins, cytochrome bd ubiquinol oxidase, PQQ (pyrroloquinoline quinone, cytochrome c550, pseudoazurin, biotin, phasins and glycolate oxidase, and in the metabolism of glutamate and phenylalanine. Noteworthy were the distinct expression patterns of genes encoding phasins, which are thought to be involved in regulating the surface/volume ratio of PHB granules. These patterns are in good agreement with the observed granule size difference between bacteroids from L. leucocephala and V. unguiculata.

  3. Toxic effects of arsenic on Sinorhizobium-Medicago sativa symbiotic interaction

    Energy Technology Data Exchange (ETDEWEB)

    Pajuelo, Eloisa [Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville (Spain); Rodriguez-Llorente, Ignacio D. [Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville (Spain)], E-mail: irodri@us.es; Dary, Mohammed; Palomares, Antonio J. [Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville (Spain)

    2008-07-15

    Recently, the Rhizobium-legume symbiotic interaction has been proposed as an interesting tool in bioremediation. However, little is known about the effect of most common contaminants on this process. The phytotoxic effects of arsenic on nodulation of Medicago sativa have been examined in vitro using the highly arsenic resistant and symbiotically effective Sinorhizobium sp. strain MA11. The bacteria were able to grow on plates containing As concentrations as high as 10 mM. Nevertheless, as little as 25-35 {mu}M arsenite produced a 75% decrease in the total number of nodules, due to a 90% reduction in the number of rhizobial infections, as could be determined using the strain MA11 carrying a lacZ reporter gene. This effect was associated to root hair damage and a shorter infective root zone. However, once nodulation was established nodule development seemed to continue normally, although earlier senescence could be observed in nodules of arsenic-grown plants. - First steps of nodulation of alfalfa, in particular infection thread formation, are more sensitive to As than nitrogen fixation due to plant effects.

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

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    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.

  5. Mutational meltdown in primary endosymbionts: selection limits Muller's ratchet.

    Directory of Open Access Journals (Sweden)

    Julie M Allen

    Full Text Available Primary bacterial endosymbionts of insects (p-endosymbionts are thought to be undergoing the process of Muller's ratchet where they accrue slightly deleterious mutations due to genetic drift in small populations with negligible recombination rates. If this process were to go unchecked over time, theory predicts mutational meltdown and eventual extinction. Although genome degradation is common among p-endosymbionts, we do not observe widespread p-endosymbiont extinction, suggesting that Muller's ratchet may be slowed or even stopped over time. For example, selection may act to slow the effects of Muller's ratchet by removing slightly deleterious mutations before they go to fixation thereby causing a decrease in nucleotide substitutions rates in older p-endosymbiont lineages.To determine whether selection is slowing the effects of Muller's ratchet, we determined the age of the Candidatus Riesia/sucking louse assemblage and analyzed the nucleotide substitution rates of several p-endosymbiont lineages that differ in the length of time that they have been associated with their insect hosts. We find that Riesia is the youngest p-endosymbiont known to date, and has been associated with its louse hosts for only 13-25 My. Further, it is the fastest evolving p-endosymbiont with substitution rates of 19-34% per 50 My. When comparing Riesia to other insect p-endosymbionts, we find that nucleotide substitution rates decrease dramatically as the age of endosymbiosis increases.A decrease in nucleotide substitution rates over time suggests that selection may be limiting the effects of Muller's ratchet by removing individuals with the highest mutational loads and decreasing the rate at which new mutations become fixed. This countering effect of selection could slow the overall rate of endosymbiont extinction.

  6. 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

  7. NAD(P)+-malic enzyme mutants of Sinorhizobium sp. strain NGR234, but not Azorhizobium caulinodans ORS571, maintain symbiotic N2 fixation capabilities.

    Science.gov (United States)

    Zhang, Ye; Aono, Toshihiro; Poole, Phillip; Finan, Turlough M

    2012-04-01

    C(4)-dicarboxylic acids appear to be metabolized via the tricarboxylic acid (TCA) cycle in N(2)-fixing bacteria (bacteroids) within legume nodules. In Sinorhizobium meliloti bacteroids from alfalfa, NAD(+)-malic enzyme (DME) is required for N(2) fixation, and this activity is thought to be required for the anaplerotic synthesis of pyruvate. In contrast, in the pea symbiont Rhizobium leguminosarum, pyruvate synthesis occurs via either DME or a pathway catalyzed by phosphoenolpyruvate carboxykinase (PCK) and pyruvate kinase (PYK). Here we report that dme mutants of the broad-host-range Sinorhizobium sp. strain NGR234 formed nodules whose level of N(2) fixation varied from 27 to 83% (plant dry weight) of the wild-type level, depending on the host plant inoculated. NGR234 bacteroids had significant PCK activity, and while single pckA and single dme mutants fixed N(2) at reduced rates, a pckA dme double mutant had no N(2)-fixing activity (Fix(-)). Thus, NGR234 bacteroids appear to synthesize pyruvate from TCA cycle intermediates via DME or PCK pathways. These NGR234 data, together with other reports, suggested that the completely Fix(-) phenotype of S. meliloti dme mutants may be specific to the alfalfa-S. meliloti symbiosis. We therefore examined the ME-like genes azc3656 and azc0119 from Azorhizobium caulinodans, as azc3656 mutants were previously shown to form Fix(-) nodules on the tropical legume Sesbania rostrata. We found that purified AZC3656 protein is an NAD(P)(+)-malic enzyme whose activity is inhibited by acetyl-coenzyme A (acetyl-CoA) and stimulated by succinate and fumarate. Thus, whereas DME is required for symbiotic N(2) fixation in A. caulinodans and S. meliloti, in other rhizobia this activity can be bypassed via another pathway(s).

  8. 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 ...

  9. 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.

  10. Genome-Wide Sensitivity Analysis of the Microsymbiont Sinorhizobium meliloti to Symbiotically Important, Defensin-Like Host Peptides

    Directory of Open Access Journals (Sweden)

    Markus F. F. Arnold

    2017-08-01

    Full Text Available The model legume species Medicago truncatula expresses more than 700 nodule-specific cysteine-rich (NCR signaling peptides that mediate the differentiation of Sinorhizobium meliloti bacteria into nitrogen-fixing bacteroids. NCR peptides are essential for a successful symbiosis in legume plants of the inverted-repeat-lacking clade (IRLC and show similarity to mammalian defensins. In addition to signaling functions, many NCR peptides exhibit antimicrobial activity in vitro and in vivo. Bacterial resistance to these antimicrobial activities is likely to be important for symbiosis. However, the mechanisms used by S. meliloti to resist antimicrobial activity of plant peptides are poorly understood. To address this, we applied a global genetic approach using transposon mutagenesis followed by high-throughput sequencing (Tn-seq to identify S. meliloti genes and pathways that increase or decrease bacterial competitiveness during exposure to the well-studied cationic NCR247 peptide and also to the unrelated model antimicrobial peptide polymyxin B. We identified 78 genes and several diverse pathways whose interruption alters S. meliloti resistance to NCR247. These genes encode the following: (i cell envelope polysaccharide biosynthesis and modification proteins, (ii inner and outer membrane proteins, (iii peptidoglycan (PG effector proteins, and (iv non-membrane-associated factors such as transcriptional regulators and ribosome-associated factors. We describe a previously uncharacterized yet highly conserved peptidase, which protects S. meliloti from NCR247 and increases competitiveness during symbiosis. Additionally, we highlight a considerable number of uncharacterized genes that provide the basis for future studies to investigate the molecular basis of symbiotic development as well as chronic pathogenic interactions.

  11. 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.

  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. Hard ticks and their bacterial endosymbionts (or would be pathogens)

    Czech Academy of Sciences Publication Activity Database

    Ahantarig, A.; Trinachartvanit, W.; Baimai, V.; Grubhoffer, Libor

    2013-01-01

    Roč. 58, č. 5 (2013), s. 419-428 ISSN 0015-5632 Institutional support: RVO:60077344 Keywords : Ixodes ricinus * Candidatus Midichloria mitochondrii * Francisella-like endosymbionts * vector Ambylomma americanum * fever group Rickettsiae * Dermacentor and ersoni * spotted fever * borne pathogens Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.145, year: 2013

  14. 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.

  15. Phenotypic and genetic diversity in Sinorhizobium meliloti and S. medicae from drought and salt affected regions of Morocco

    Directory of Open Access Journals (Sweden)

    Udupa Sripada M

    2010-01-01

    Full Text Available Abstract Background Sinorhizobium meliloti and S. medicae are symbiotic nitrogen fixing bacteria in root nodules of forage legume alfalfa (Medicago sativa L.. In Morocco, alfalfa is usually grown in marginal soils of arid and semi-arid regions frequently affected by drought, extremes of temperature and soil pH, soil salinity and heavy metals, which affect biological nitrogen fixing ability of rhizobia and productivity of the host. This study examines phenotypic diversity for tolerance to the above stresses and genotypic diversity at Repetitive Extragenic Pallindromic DNA regions of Sinorhizobium nodulating alfalfa, sampled from marginal soils of arid and semi-arid regions of Morocco. Results RsaI digestion of PCR amplified 16S rDNA of the 157 sampled isolates, assigned 136 isolates as S. meliloti and the rest as S. medicae. Further phenotyping of these alfalfa rhizobia for tolerance to the environmental stresses revealed a large degree of variation: 55.41%, 82.16%, 57.96% and 3.18% of the total isolates were tolerant to NaCl (>513 mM, water stress (-1.5 MPa, high temperature (40°C and low pH (3.5, respectively. Sixty-seven isolates of S. meliloti and thirteen isolates of S. medicae that were tolerant to salinity were also tolerant to water stress. Most of the isolates of the two species showed tolerance to heavy metals (Cd, Mn and Zn and antibiotics (chloramphenicol, spectinomycin, streptomycin and tetracycline. The phenotypic clusters observed by the cluster analysis clearly showed adaptations of the S. meliloti and S. medicae strains to the multiple stresses. Genotyping with rep-PCR revealed higher genetic diversity within these phenotypic clusters and classified all the 157 isolates into 148 genotypes. No relationship between genotypic profiles and the phenotypes was observed. The Analysis of Molecular Variance revealed that largest proportion of significant (P Conclusion High degree of phenotypic and genotypic diversity is present in S

  16. The Sinorhizobium meliloti RNA chaperone Hfq influences central carbon metabolism and the symbiotic interaction with alfalfa

    Directory of Open Access Journals (Sweden)

    Jiménez-Zurdo José I

    2010-03-01

    Full Text Available Abstract Background The bacterial Hfq protein is able to interact with diverse RNA molecules, including regulatory small non-coding RNAs (sRNAs, and thus it is recognized as a global post-transcriptional regulator of gene expression. Loss of Hfq has an extensive impact in bacterial physiology which in several animal pathogens influences virulence. Sinorhizobium meliloti is a model soil bacterium known for its ability to establish a beneficial nitrogen-fixing intracellular symbiosis with alfalfa. Despite the predicted general involvement of Hfq in the establishment of successful bacteria-eukaryote interactions, its function in S. meliloti has remained unexplored. Results Two independent S. meliloti mutants, 2011-3.4 and 1021Δhfq, were obtained by disruption and deletion of the hfq gene in the wild-type strains 2011 and 1021, respectively, both exhibiting similar growth defects as free-living bacteria. Transcriptomic profiling of 1021Δhfq revealed a general down-regulation of genes of sugar transporters and some enzymes of the central carbon metabolism, whereas transcripts specifying the uptake and metabolism of nitrogen sources (mainly amino acids were more abundant than in the wild-type strain. Proteomic analysis of the 2011-3.4 mutant independently confirmed these observations. Symbiotic tests showed that lack of Hfq led to a delayed nodulation, severely compromised bacterial competitiveness on alfalfa roots and impaired normal plant growth. Furthermore, a large proportion of nodules (55%-64% elicited by the 1021Δhfq mutant were non-fixing, with scarce content in bacteroids and signs of premature senescence of endosymbiotic bacteria. RT-PCR experiments on RNA from bacteria grown under aerobic and microoxic conditions revealed that Hfq contributes to regulation of nifA and fixK1/K2, the genes controlling nitrogen fixation, although the Hfq-mediated regulation of fixK is only aerobiosis dependent. Finally, we found that some of the recently

  17. 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.

  18. Transcriptome Response to Heavy Metals in Sinorhizobium meliloti CCNWSX0020 Reveals New Metal Resistance Determinants That Also Promote Bioremediation by Medicago lupulina in Metal-Contaminated Soil.

    Science.gov (United States)

    Lu, Mingmei; Jiao, Shuo; Gao, Enting; Song, Xiuyong; Li, Zhefei; Hao, Xiuli; Rensing, Christopher; Wei, Gehong

    2017-10-15

    The symbiosis of the highly metal-resistant Sinorhizobium meliloti CCNWSX0020 and Medicago lupulina has been considered an efficient tool for bioremediation of heavy metal-polluted soils. However, the metal resistance mechanisms of S. meliloti CCNWSX00200 have not been elucidated in detail. Here we employed a comparative transcriptome approach to analyze the defense mechanisms of S. meliloti CCNWSX00200 against Cu or Zn exposure. Six highly upregulated transcripts involved in Cu and Zn resistance were identified through deletion mutagenesis, including genes encoding a multicopper oxidase (CueO), an outer membrane protein (Omp), sulfite oxidoreductases (YedYZ), and three hypothetical proteins (a CusA-like protein, a FixH-like protein, and an unknown protein), and the corresponding mutant strains showed various degrees of sensitivity to multiple metals. The Cu-sensitive mutant (Δ cueO ) and three mutants that were both Cu and Zn sensitive (Δ yedYZ , Δ cusA -like, and Δ fixH -like) were selected for further study of the effects of these metal resistance determinants on bioremediation. The results showed that inoculation with the Δ cueO mutant severely inhibited infection establishment and nodulation of M. lupulina under Cu stress, while inoculation with the Δ yedYZ and Δ fixH -like mutants decreased just the early infection frequency and nodulation under Cu and Zn stresses. In contrast, inoculation with the Δ cusA -like mutant almost led to loss of the symbiotic capacity of M. lupulina to even grow in uncontaminated soil. Moreover, the antioxidant enzyme activity and metal accumulation in roots of M. lupulina inoculated with all mutants were lower than those with the wild-type strain. These results suggest that heavy metal resistance determinants may promote bioremediation by directly or indirectly influencing formation of the rhizobium-legume symbiosis. IMPORTANCE Rhizobium-legume symbiosis has been promoted as an appropriate tool for bioremediation of heavy

  19. 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...

  20. 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 ...

  1. 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.

  2. Diversity, frequency, and geographic distribution of facultative bacterial endosymbionts in introduced aphid pests.

    Science.gov (United States)

    Sepúlveda, Daniela A; Zepeda-Paulo, Francisca; Ramírez, Claudio C; Lavandero, Blas; Figueroa, Christian C

    2017-06-01

    Facultative bacterial endosymbionts in insects have been under intense study during the last years. Endosymbionts can modify the insect's phenotype, conferring adaptive advantages under environmental stress. This seems particularly relevant for a group of worldwide agricultural aphid pests, because endosymbionts modify key fitness-related traits, including host plant use, protection against natural enemies and heat tolerance. Aimed to understand the role of facultative endosymbionts on the success of introduced aphid pests, the distribution and abundance of 5 facultative endosymbionts (Hamiltonella defensa, Regiella insecticola, Serratia symbiotica, Rickettsia and Spiroplasma) were studied and compared in 4 cereal aphids (Sitobion avenae, Diuraphis noxia, Metopolophium dirhodum and Schizaphis graminium) and in the pea aphid Acyrthosiphon pisum complex from 2 agroclimatic zones in Chile. Overall, infections with facultative endosymbionts exhibited a highly variable and characteristic pattern depending on the aphid species/host race and geographic zone, which could explain the success of aphid pest populations after their introduction. While S. symbiotica and H. defensa were the most frequent endosymbionts carried by the A. pisum pea-race and A. pisum alfalfa-race aphids, respectively, the most frequent facultative endosymbiont carried by all cereal aphids was R. insecticola. Interestingly, a highly variable composition of endosymbionts carried by S. avenae was also observed between agroclimatic zones, suggesting that endosymbionts are responding differentially to abiotic variables (temperature and precipitations). In addition, our findings constitute the first report of bacterial endosymbionts in cereal aphid species not screened before, and also the first report of aphid endosymbionts in Chile. © 2016 Institute of Zoology, Chinese Academy of Sciences.

  3. Degenerative minimalism in the genome of a psyllid endosymbiont.

    Science.gov (United States)

    Clark, M A; Baumann, L; Thao, M L; Moran, N A; Baumann, P

    2001-03-01

    Psyllids, like aphids, feed on plant phloem sap and are obligately associated with prokaryotic endosymbionts acquired through vertical transmission from an ancestral infection. We have sequenced 37 kb of DNA of the genome of Carsonella ruddii, the endosymbiont of psyllids, and found that it has a number of unusual properties revealing a more extreme case of degeneration than was previously reported from studies of eubacterial genomes, including that of the aphid endosymbiont Buchnera aphidicola. Among the unusual properties are an exceptionally low guanine-plus-cytosine content (19.9%), almost complete absence of intergenic spaces, operon fusion, and lack of the usual promoter sequences upstream of 16S rDNA. These features suggest the synthesis of long mRNAs and translational coupling. The most extreme instances of base compositional bias occur in the genes encoding proteins that have less highly conserved amino acid sequences; the guanine-plus-cytosine content of some protein-coding sequences is as low as 10%. The shift in base composition has a large effect on proteins: in polypeptides of C. ruddii, half of the residues consist of five amino acids with codons low in guanine plus cytosine. Furthermore, the proteins of C. ruddii are reduced in size, with an average of about 9% fewer amino acids than in homologous proteins of related bacteria. These observations suggest that the C. ruddii genome is not subject to constraints that limit the evolution of other known eubacteria.

  4. 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.

  5. Phenotypic and molecular characterization of Sinorhizobium meliloti strains isolated from the roots of Medicago sativa in Iran

    Directory of Open Access Journals (Sweden)

    Mahboobeh Nakhaei Moghaddam

    2017-12-01

    Full Text Available Introduction: The Rhizobium-legume interaction leads to biological nitrogen-fixation and increases nitrogen of soil. The aim of this study was to characterize the properties of Sinorhizobium isolates from the roots of alfalfa plantsin Iran. Materials and methods: Bacteria were isolated in yeast extract mannitol Agar and confirmed by plant infection test. After evaluation from the point of morphological and biochemical properties, a fragment of 16S rDNA gene with a size of approximately 1500 base pair was amplified using fD1 and rD1 primers. PCR (polymerase chain reaction products were analyzed for digestion pattern by Taq1 endonuclease. Results: 63 bacteria were isolated from homogenized nodules. 42 isolates generated nodules in three replicates in infection test. Of the 42 isolates 8, were resistant to salinity. Seven isolates had better growth than others at pH 4. All isolates were resistant to CuCl2 (0.5 mmol, CdCl2 (0.65 mmol, MnSO4 (0.75 and 1.5 mmol and ZnSO4 (0.125 mmol. Isolates S3Q and S22K were more resistant to salinity, acidity, temperature and heavy metals stresses. PCR products of all bacteria had the same restricted profile after digestion by Taq1 nuclease. Discussion and conclusion: The results showed that among isolated bacteria, there were some differences in the resistance to salinity, acidity, temperature and heavy metals stresses.  Identification of native strains of rhizobia, especially strains resistant to salinity, temperature, heavy metals and acidity could be valuable due to their potentiality for using biological fertilizers in harsh conditions.

  6. Sinorhizobium meliloti YbeY is an endoribonuclease with unprecedented catalytic features, acting as silencing enzyme in riboregulation.

    Science.gov (United States)

    Saramago, Margarida; Peregrina, Alexandra; Robledo, Marta; Matos, Rute G; Hilker, Rolf; Serrania, Javier; Becker, Anke; Arraiano, Cecilia M; Jiménez-Zurdo, José I

    2017-02-17

    Structural and biochemical features suggest that the almost ubiquitous bacterial YbeY protein may serve catalytic and/or Hfq-like protective functions central to small RNA (sRNA)-mediated regulation and RNA metabolism. We have biochemically and genetically characterized the YbeY ortholog of the legume symbiont Sinorhizobium meliloti (SmYbeY). Co-immunoprecipitation (CoIP) with a FLAG-tagged SmYbeY yielded a poor enrichment in RNA species, compared to Hfq CoIP-RNA uncovered previously by a similar experimental setup. Purified SmYbeY behaved as a monomer that indistinctly cleaved single- and double-stranded RNA substrates, a unique ability among bacterial endoribonucleases. SmYbeY-mediated catalysis was supported by the divalent metal ions Mg2+, Mn2+ and Ca2+, which influenced in a different manner cleavage efficiency and reactivity patterns, with Ca2+ specifically blocking activity on double-stranded and some structured RNA molecules. SmYbeY loss-of-function compromised expression of core energy and RNA metabolism genes, whilst promoting accumulation of motility, late symbiotic and transport mRNAs. Some of the latter transcripts are known Hfq-binding sRNA targets and might be SmYbeY substrates. Genetic reporter and in vitro assays confirmed that SmYbeY is required for sRNA-mediated down-regulation of the amino acid ABC transporter prbA mRNA. We have thus discovered a bacterial endoribonuclease with unprecedented catalytic features, acting also as gene silencing enzyme.

  7. Nutritional upgrading for omnivorous carpenter ants by the endosymbiont Blochmannia

    Directory of Open Access Journals (Sweden)

    Mueller Martin J

    2007-10-01

    Full Text Available Abstract Background Carpenter ants (genus Camponotus are considered to be omnivores. Nonetheless, the genome sequence of Blochmannia floridanus, the obligate intracellular endosymbiont of Camponotus floridanus, suggests a function in nutritional upgrading of host resources by the bacterium. Thus, the strongly reduced genome of the endosymbiont retains genes for all subunits of a functional urease, as well as those for biosynthetic pathways for all but one (arginine of the amino acids essential to the host. Results Nutritional upgrading by Blochmannia was tested in 90-day feeding experiments with brood-raising in worker-groups on chemically defined diets with and without essential amino acids and treated or not with antibiotics. Control groups were fed with cockroaches, honey water and Bhatkar agar. Worker-groups were provided with brood collected from the queenright mother-colonies (45 eggs and 45 first instar larvae each. Brood production did not differ significantly between groups of symbiotic workers on diets with and without essential amino acids. However, aposymbiotic worker groups raised significantly less brood on a diet lacking essential amino acids. Reduced brood production by aposymbiotic workers was compensated when those groups were provided with essential amino acids in their diet. Decrease of endosymbionts due to treatment with antibiotic was monitored by qRT-PCR and FISH after the 90-day experimental period. Urease function was confirmed by feeding experiments using 15N-labelled urea. GC-MS analysis of 15N-enrichment of free amino acids in workers revealed significant labelling of the non-essential amino acids alanine, glycine, aspartic acid, and glutamic acid, as well as of the essential amino acids methionine and phenylalanine. Conclusion Our results show that endosymbiotic Blochmannia nutritionally upgrade the diet of C. floridanus hosts to provide essential amino acids, and that it may also play a role in nitrogen recycling

  8. 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.

  9. Sinorhizobium meliloti can protect Medicago truncatula against Phoma medicaginis attack

    Directory of Open Access Journals (Sweden)

    Moncef MRABET

    2011-09-01

    Full Text Available The Sinorhizobium meliloti microsymbiont of Medicago spp. was used in an antibiosis test against Phoma medicaginis and in bioprotection assays of Medicago truncatula JA17 from the pathogen. Among 17 S. meliloti strains isolated from root nodules of M. truncatula and Medicago laciniata grown in Tunisian soils, six showed up to 60% growth inhibition of five P. medicaginis strains isolated from infected field-grown M. truncatula. Two S. meliloti strains with differing in vitro effects on P. medicaginis, 10.16/R6 antagonist and 5M6 non antagonist, were used in a bioprotection assay of M. truncatula JA17 from the pathogen. The inoculation of P. medicaginis caused complete root and stem rotting, and the mortality of all treated plantlets. Inoculation of the antagonist S. meliloti strain 10.16/R6 to M. truncatula JA17 infected with P. medicaginis was associated with a significant 65% decrease of vegetative rotting length, an 80% decrease of plant mortality, an increase of root length, and enhancement of root and shoot biomass comparatively to control plantlets treated with P. medicaginis. The inoculation of the non antagonistic S. meliloti strain 5M6 slightly decreased disease and slightly increased plant growth parameters.

  10. Structure and Biological Roles of Sinorhizobium fredii HH103 Exopolysaccharide

    Science.gov (United States)

    Acosta-Jurado, Sebastián; Soto, María J.; Margaret, Isabel; Crespo-Rivas, Juan C.; Sanjuan, Juan; Temprano, Francisco; Gil-Serrano, Antonio; Ruiz-Sainz, José E.; Vinardell, José M.

    2014-01-01

    Here we report that the structure of the Sinorhizobium fredii HH103 exopolysaccharide (EPS) is composed of glucose, galactose, glucuronic acid, pyruvic acid, in the ratios 5∶2∶2∶1 and is partially acetylated. A S. fredii HH103 exoA mutant (SVQ530), unable to produce EPS, not only forms nitrogen fixing nodules with soybean but also shows increased competitive capacity for nodule occupancy. Mutant SVQ530 is, however, less competitive to nodulate Vigna unguiculata. Biofilm formation was reduced in mutant SVQ530 but increased in an EPS overproducing mutant. Mutant SVQ530 was impaired in surface motility and showed higher osmosensitivity compared to its wild type strain in media containing 50 mM NaCl or 5% (w/v) sucrose. Neither S. fredii HH103 nor 41 other S. fredii strains were recognized by soybean lectin (SBL). S. fredii HH103 mutants affected in exopolysaccharides (EPS), lipopolysaccharides (LPS), cyclic glucans (CG) or capsular polysaccharides (KPS) were not significantly impaired in their soybean-root attachment capacity, suggesting that these surface polysaccharides might not be relevant in early attachment to soybean roots. These results also indicate that the molecular mechanisms involved in S. fredii attachment to soybean roots might be different to those operating in Bradyrhizobium japonicum. PMID:25521500

  11. Maintenance of algal endosymbionts in Paramecium bursaria: a simple model based on population dynamics.

    Science.gov (United States)

    Iwai, Sosuke; Fujiwara, Kenji; Tamura, Takuro

    2016-09-01

    Algal endosymbiosis is widely distributed in eukaryotes including many protists and metazoans, and plays important roles in aquatic ecosystems, combining phagotrophy and phototrophy. To maintain a stable symbiotic relationship, endosymbiont population size in the host must be properly regulated and maintained at a constant level; however, the mechanisms underlying the maintenance of algal endosymbionts are still largely unknown. Here we investigate the population dynamics of the unicellular ciliate Paramecium bursaria and its Chlorella-like algal endosymbiont under various experimental conditions in a simple culture system. Our results suggest that endosymbiont population size in P. bursaria was not regulated by active processes such as cell division coupling between the two organisms, or partitioning of the endosymbionts at host cell division. Regardless, endosymbiont population size was eventually adjusted to a nearly constant level once cells were grown with light and nutrients. To explain this apparent regulation of population size, we propose a simple mechanism based on the different growth properties (specifically the nutrient requirements) of the two organisms, and based from this develop a mathematical model to describe the population dynamics of host and endosymbiont. The proposed mechanism and model may provide a basis for understanding the maintenance of algal endosymbionts. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  12. A Sinorhizobium meliloti-specific N-acyl homoserine lactone quorum-sensing signal increases nodule numbers in Medicago truncatula independent of autoregulation

    Directory of Open Access Journals (Sweden)

    Debora Fabiola Veliz Vallejos

    2014-10-01

    Full Text Available N-acyl homoserine lactones (AHLs act as quorum sensing signals that regulate cell-density dependent behaviors in many gram-negative bacteria, in particular those important for plant-microbe interactions. AHLs can also be recognized by plants, and this may influence their interactions with bacteria. Here we tested whether the exposure to AHLs affects the nodule-forming symbiosis between legume hosts and rhizobia. We treated roots of the model legume, Medicago truncatula, with a range of AHLs either from its specific symbiont, Sinorhizobium meliloti, or from the potential pathogens, Pseudomonas aeruginosa and Agrobacterium vitis. We found increased numbers of nodules formed on root systems treated with the S. meliloti-specific AHL, 3-oxo-C14-homoserine lactone, at a concentration of 1 μM, while the other AHLs did not result in significant changes to nodule numbers. We did not find any evidence for altered nodule invasion by the rhizobia. Quantification of flavonoids that could act as nod gene inducers in S. meliloti did not show any correlation with increased nodule numbers. The effects of AHLs were specific for an increase in nodule numbers, but not lateral root numbers or root length. Increased nodule numbers following 3-oxo-C14-homoserine lactone treatment were under control of autoregulation of nodulation and were still observed in the autoregulation mutant, sunn4 (super numeric nodules4. However, increases in nodule numbers by 3-oxo-C14-homoserine lactone were not found in the ethylene-insensitive sickle mutant. A comparison between M. truncatula with M. sativa (alfalfa and Trifolium repens (white clover showed that the observed effects of AHLs on nodule numbers were specific to M. truncatula, despite M. sativa nodulating with the same symbiont. We conclude that plant perception of the S. meliloti-specific 3-oxo-C14-homoserine lactone influences nodule numbers in M. truncatula via an ethylene-dependent, but autoregulation

  13. 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.

  14. 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.

  15. The histones of the endosymbiont alga of Peridinium balticum (Dinophyceae).

    Science.gov (United States)

    Rizzo, P J; Morris, R L; Zweidler, A

    1988-01-01

    The histones of the endosymbiont nucleus of the binucleate dinoflagellate Peridinium balticum were characterized by amino acid analysis and peptide mapping, and compared to calf thymus histones. Using these and various other criteria we have identified two H1-like histones as well as the highly conserved histones H3 and H4. A 13,000 dalton component in sodium dodecyl sulphate (SDS) gels can be separated into two components in Triton-containing gels. We suggest that these histones (HPb1 and HPb2) correspond to the vertebrate histones H2A and H2B, respectively.

  16. Influence of different Sinorhizobium meliloti inocula on abundance of genes involved in nitrogen transformations in the rhizosphere of alfalfa (Medicago sativa L.).

    Science.gov (United States)

    Babić, Katarina Huić; Schauss, Kristina; Hai, Brigitte; Sikora, Sanja; Redzepović, Sulejman; Radl, Viviane; Schloter, Michael

    2008-11-01

    Inoculation of leguminous seeds with selected rhizobial strains is practised in agriculture to ameliorate the plant yield by enhanced root nodulation and nitrogen uptake of the plant. However, effective symbiosis between legumes and rhizobia does not only depend on the capacity of nitrogen fixation but also on the entire nitrogen turnover in the rhizosphere. We investigated the influence of seed inoculation with two indigenous Sinorhizobium meliloti strains exhibiting different efficiency concerning plant growth promotion on nitrogen turnover processes in the rhizosphere during the growth of alfalfa. Quantification of six target genes (bacterial amoA, nirK, nirS, nosZ, nifH and archaeal amoA) within the nitrogen cycle was performed in rhizosphere samples before nodule formation, at bud development and at the late flowering stage. The results clearly demonstrated that effectiveness of rhizobial inocula is related to abundance of nifH genes in the late flowering phase of alfalfa. Moreover, other genes involved in nitrogen turnover had been affected by the inocula, e.g. higher numbers of amoA copies were observed during flowering when the more effective strain had been inoculated. However, the respective gene abundances differed overall to a greater extent between the three plant development stages than between the inoculation variants.

  17. Biochemical and Molecular Phylogenetic Study of Agriculturally Useful Association of a Nitrogen-Fixing Cyanobacterium and Nodule Sinorhizobium with Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    E. V. Karaushu

    2015-01-01

    Full Text Available Seed inoculation with bacterial consortium was found to increase legume yield, providing a higher growth than the standard nitrogen treatment methods. Alfalfa plants were inoculated by mono- and binary compositions of nitrogen-fixing microorganisms. Their physiological and biochemical properties were estimated. Inoculation by microbial consortium of Sinorhizobium meliloti T17 together with a new cyanobacterial isolate Nostoc PTV was more efficient than the single-rhizobium strain inoculation. This treatment provides an intensification of the processes of biological nitrogen fixation by rhizobia bacteria in the root nodules and an intensification of plant photosynthesis. Inoculation by bacterial consortium stimulates growth of plant mass and rhizogenesis and leads to increased productivity of alfalfa and to improving the amino acid composition of plant leaves. The full nucleotide sequence of the rRNA gene cluster and partial sequence of the dinitrogenase reductase (nifH gene of Nostoc PTV were deposited to GenBank (JQ259185.1, JQ259186.1. Comparison of these gene sequences of Nostoc PTV with all sequences present at the GenBank shows that this cyanobacterial strain does not have 100% identity with any organisms investigated previously. Phylogenetic analysis showed that this cyanobacterium clustered with high credibility values with Nostoc muscorum.

  18. Biochemical and Molecular Phylogenetic Study of Agriculturally Useful Association of a Nitrogen-Fixing Cyanobacterium and Nodule Sinorhizobium with Medicago sativa L.

    Science.gov (United States)

    Karaushu, E V; Lazebnaya, I V; Kravzova, T R; Vorobey, N A; Lazebny, O E; Kiriziy, D A; Olkhovich, O P; Taran, N Yu; Kots, S Ya; Popova, A A; Omarova, E; Koksharova, O A

    2015-01-01

    Seed inoculation with bacterial consortium was found to increase legume yield, providing a higher growth than the standard nitrogen treatment methods. Alfalfa plants were inoculated by mono- and binary compositions of nitrogen-fixing microorganisms. Their physiological and biochemical properties were estimated. Inoculation by microbial consortium of Sinorhizobium meliloti T17 together with a new cyanobacterial isolate Nostoc PTV was more efficient than the single-rhizobium strain inoculation. This treatment provides an intensification of the processes of biological nitrogen fixation by rhizobia bacteria in the root nodules and an intensification of plant photosynthesis. Inoculation by bacterial consortium stimulates growth of plant mass and rhizogenesis and leads to increased productivity of alfalfa and to improving the amino acid composition of plant leaves. The full nucleotide sequence of the rRNA gene cluster and partial sequence of the dinitrogenase reductase (nifH) gene of Nostoc PTV were deposited to GenBank (JQ259185.1, JQ259186.1). Comparison of these gene sequences of Nostoc PTV with all sequences present at the GenBank shows that this cyanobacterial strain does not have 100% identity with any organisms investigated previously. Phylogenetic analysis showed that this cyanobacterium clustered with high credibility values with Nostoc muscorum.

  19. 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...

  20. Identification of Salt-Tolerant Sinorhizobium sp Strain BL3 Membrane Proteins Based on Proteomics

    DEFF Research Database (Denmark)

    Tanthanuch, Waraporn; Mohammed, Shabaz; Matthiesen, Rune

    2010-01-01

    Sinorhizobium sp. BL3 is a salt-tolerant strain that can fix atmospheric nitrogen in symbiosis with leguminous host plants under salt-stress conditions. Since cell membranes are the first barrier to environmental change, it is interesting to explore the membrane proteins within this protective...

  1. 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)....

  2. Interaction between Nitrogen and Phosphate Stress Responses in Sinorhizobium meliloti

    Directory of Open Access Journals (Sweden)

    Kelly Lynn Hagberg

    2016-11-01

    Full Text Available Bacteria have developed various stress response pathways to improve their assimilation and allocation of limited nutrients, such as nitrogen and phosphate. While both the Nitrogen Stress Response (NSR and Phosphate Stress Response (PSR have been studied individually, there are few experiments reported that characterize effects of multiple stresses on one or more pathways in Sinorhizobium meliloti, a facultatively symbiotic, nitrogen-fixing bacteria. The PII proteins, GlnB and GlnK, regulate the NSR activity, but analysis of global transcription changes in a PII deficient mutant suggest that the S. meliloti PII proteins may also regulate the PSR. PII double deletion mutants grow very slowly and pseudoreversion of the slow growth phenotype is common. To understand this phenomenon better, transposon mutants were isolated that had a faster growing phenotype. One mutation was in phoB, the response regulator for a two component regulatory system that is important in the PSR. phoB::Tn5 mutants had different phenotypes in the wild type compared to a PII deficient background. This led to the hypothesis that phosphate stress affects the NSR and conversely, that nitrogen stress affects the PSR. Our results show that phosphate availability affects glutamine synthetase activity and expression, which are often used as indicators of NSR activity, but that nitrogen availability did not affect alkaline phosphatase activity and expression, which are indicators of PSR activity. We conclude that the NSR is co-regulated by nitrogen and phosphate, whereas the PSR does not appear to be co-regulated by nitrogen in addition to its known phosphate regulation.

  3. [Occurrence of islands in genomes of Sinorhizobium meliloti native isolates].

    Science.gov (United States)

    Muntyan, V S; Cherkasova, M E; Andronov, E E; Simarov, B V; Roumiantseva, M L

    2016-10-01

    Genomes of 184 Sinorhizobium meliloti native isolates were studied to test the occurence of islands Sme21T, Sme19T, and Sme80S previously described in the model strain Rm1021. This analysis was conducted using PCR methodology involving specific primers. It was demonstrated that, in the examined geographically distinct populations of S. meliloti from the Northern Caucasus (NCG) and the Aral Sea region (PAG), the strains containing genomic islands were observed with similar frequency (0.55 and 0.57, respectively). Island Sme80S, denoted as an island of “environmental adaptivity,” was identified predominantly (frequency of 0.38) in genomes of strains which exhibited a lower level of salt tolerance and was isolated in PAG, a modern center of introgressive hybridization of alfalfa subjected to salinity. Island Sme21T designated as “ancestral” was observed in genomes of strains isolated in NCG, the primary center of host-plant biodiversity, 10-fold more often than in strains from PAG. An island Sme19T, which predominantly carries genes encoding transposases, was observed in genomes of strains in both populations with average frequency of 0.10. The analysis of linkage disequilibrium (LD) based on the assessment of probability for detection of different islands combinations in genomes revealed an independent inheritance of islands in salt-sensitive strains of various geographic origin. In contrast, the absence of this trend was noted in the majority of the examined combinations of salt-tolerant strains. It was concluded that the structure of chromosome in PAG strains which predominantly possessed a salt-sensitive phenotype was subjected to active recombinant processes, which could predetermine the intensity of microevolutionary processes in bacterial populations and facilitate an adaptation of bacteria in adverse environmental effect.

  4. Bacteria Endosymbiont, Wolbachia, Promotes Parasitism of Parasitoid Wasp Asobara japonica.

    Directory of Open Access Journals (Sweden)

    Shunsuke Furihata

    Full Text Available Wolbachia is the most widespread endosymbiotic bacterium that manipulates reproduction of its arthropod hosts to enhance its own spread throughout host populations. Infection with Wolbachia causes complete parthenogenetic reproduction in many Hymenoptera, producing only female offspring. The mechanism of such reproductive manipulation by Wolbachia has been extensively studied. However, the effects of Wolbachia symbiosis on behavioral traits of the hosts are scarcely investigated. The parasitoid wasp Asobara japonica is an ideal insect to investigate this because symbiotic and aposymbiotic strains are available: Wolbachia-infected Tokyo (TK and noninfected Iriomote (IR strains originally collected on the main island and southwest islands of Japan, respectively. We compared the oviposition behaviors of the two strains and found that TK strain females parasitized Drosophila melanogaster larvae more actively than the IR strain, especially during the first two days after eclosion. Removing Wolbachia from the TK strain wasps by treatment with tetracycline or rifampicin decreased their parasitism activity to the level of the IR strain. Morphological and behavioral analyses of both strain wasps showed that Wolbachia endosymbionts do not affect development of the host female reproductive tract and eggs, but do enhance host-searching ability of female wasps. These results suggest the possibility that Wolbachia endosymbionts may promote their diffusion and persistence in the host A. japonica population not only at least partly by parthenogenesis but also by enhancement of oviposition frequency of the host females.

  5. 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...

  6. Methods for the Extraction of Endosymbionts from the Whitefly Bemisia tabaci.

    Science.gov (United States)

    Zhu, Dan-Tong; Wang, Xin-Ru; Ban, Fei-Xue; Zou, Chi; Liu, Shu-Sheng; Wang, Xiao-Wei

    2017-06-19

    Bacterial symbionts form an intimate relationship with their hosts and confer advantages to the hosts in most cases. Genomic information is critical to study the functions and evolution of bacterial symbionts in their host. As most symbionts cannot be cultured in vitro, methods to isolate an adequate quantity of bacteria for genome sequencing are very important. In the whitefly Bemisia tabaci, a number of endosymbionts have been identified and are predicted to be of importance in the development and reproduction of the pests through multiple approaches. However, the mechanism underpinning the associations remains largely unknown. The obstacle partially comes from the fact that the endosymbionts in whitefly, mostly restrained in bacteriocytes, are hard to separate from the host cells. Here we report a step-by-step protocol for the identification, extraction and purification of endosymbionts from the whitefly B. tabaci mainly by dissection and filtration. Endosymbiont samples prepared by this method, although still a mixture of different endosymbiont species, are suitable for subsequent genome sequencing and analysis of the possible roles of endosymbionts in B. tabaci. This method may also be used to isolate endosymbionts from other insects.

  7. 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....

  8. 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...

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. Evidence for metabolic provisioning by a common invertebrate endosymbiont, Wolbachia pipientis, during periods of nutritional stress.

    NARCIS (Netherlands)

    Brownlie, J.C.; Cass, B.N.; Riegler, M.; Witsenburg, J.J.; Iturbe-Ormaetxe, I.; McGraw, E.A.; O'Neill, S.L.

    2009-01-01

    Wolbachia are ubiquitous inherited endosymbionts of invertebrates that invade host populations by modifying host reproductive systems. However, some strains lack the ability to impose reproductive modification and yet are still capable of successfully invading host populations. To explain this

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Sinorhizobium meliloti putA Gene Regulation: a New Model within the Family Rhizobiaceae

    OpenAIRE

    Soto, María José; Jiménez-Zurdo, José Ignacio; van Dillewijn, Pieter; Toro, Nicolás

    2000-01-01

    Proline dehydrogenase (PutA) is a bifunctional enzyme that catalyzes the oxidation of proline to glutamate. In Sinorhizobium meliloti, as in other microorganisms, the putA gene is transcriptionally activated in response to proline. In Rhodobacter capsulatus, Agrobacterium, and most probably in Bradyrhizobium, this activation is dependent on an Lrp-like protein encoded by the putR gene, located immediately upstream of putA. Interestingly, sequence and genetic analysis of the region upstream of...

  19. The effect of phosphate deficiency on quorum sensing signaling pathway of Sinorhizobium meliloti

    OpenAIRE

    Najmeh Pakdaman; akbar mostajeran

    2015-01-01

      Introduction : Phosphorus is one of the most essential macroelements for bacterial cells. Since phosphate (PO4-3) limitation is frequently encountered in soils, bacteria developed some mechanisms in response to this sever condition. Phosphate transporter (PstS) and proteins involved in quorum sensing (QS) signaling pathway are affected by mediating PhoB, response regulator, following phosphate starvation. QS system of Sinorhizobium meliloti composed of at least three genes of sinI (autoindu...

  20. Three way interactions between Thymus vulgaris, Medicago truncatula and Sinorhizobium meliloti

    OpenAIRE

    Grøndahl, Eva; Ehlers, Bodil Kirstine

    2012-01-01

    Thymus vulgaris is a dominating component of the Mediterranean garrigue vegetation. It produces aromatic oil, containing monoterpenes, which affects the performance (growth, survival) of other plants, and microorganisms. Annual plant species of the genus Medicago are commonly found in Mediterranean thyme communities; in fact they often grow very close to thyme plants (within 1 square meter). Medicago has a symbiosis with the nitrogen fixing bacteria Sinorhizobium meliloti – which is essential...

  1. Biodegradable plastics from Sinorhizobium meliloti as plastics compatible with the environment and human health

    Directory of Open Access Journals (Sweden)

    Mehrdad Hashemi Beidokhti

    2016-03-01

    Full Text Available Introduction: Polyhydroxyalkanoates (PHAs are natural polyesters and biodegradable plastics that are stored as intracellular inclusion bodies by a great variety of bacteria. The aim of this study was to extract polyhydroxyalkanoate from native Sinorhizobium meliloti in Iran. Materials and methods: Sinorhizobium meliloti isolates were collected from roots of alfalfa plants and were identified by Gram staining, biochemical experiments and amplification of 1500 bp fragment of 16Sr DNA gene. PHA granules were detected by microscopic examination. PHA production was evaluated in nutrient deficient medium and its amount was determined by conversion of PHA into crotonic acid by sulphuric acid treatment. The effect of various temperatures, agitation rate and carbon source (sucrose, mannitol, and maltose were evaluated on dry cell weight and polyhydroxybutyrate (PHB production. Results: The maximum amount of polymer production (43.10% was seen in basal mineral medium at 29°C, pH~7 and 215 revolutions per minute (rpm. The results of this research showed that the S5 isolate was capable to produce maximum poly3- hydroxybutyrate. The produced polymer was analyzed for its purity by GC- mass (gas chromatography- mass spectroscopy and confirmed to be PHB compared with the standard polymer. Discussion and conclusion: Native strains of Sinorhizobium can be used in the production of biodegradable plastics and the results of present study showed that S. meliloti S5 was capable to produce maximum PHB at 29°C, agitation rate of 215 rpm, and pH~7. 

  2. 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.

  3. Genetic variability of the whitefly Bemisia tabaci and its secondary endosymbionts in the Arabian Peninsula

    KAUST Repository

    Ragab, Alaa I.

    2013-05-01

    The whitefly Bemisia tabaci species complex has been well documented as one of the most economically important emergent plant virus vectors, through serious feeding damage to its broad range of plant hosts and transmission of plant viruses to important agricultural crops. It has been shown to have associations with endosymbionts which have significant effects on the insect fitness. The purpose of this study was to provide information for the biotype and secondary endosymbiont distribution for B. tabaci populations in the relatively unstudied Arabian peninsula. The geographical localization and variation in endosymbiont populations across the region were identified using a sequence-driven analysis of the population genetics of the secondary endosymbiont. Live field specimens were collected from 22 different locations in the region and preserved in 70% ethanol for genetic studies. Previously established procedures were used to extract and purify total insect DNA from 24-30 individual whiteflies for each location (Frohlich et al., 1999; Chiel et al., 2007). Specimens were subjected to PCR amplification using the respective 16S rDNAprimers for the Rickettsia, Hamiltonella, and Wolbachia to amplify endosymbiont DNA. PCR was run with primers for the highly conserved whitefly mitochondrial cytochrome oxidase subunit I (COI) gene for biotyping. Samples were sequenced using the Sanger method and the data analyzed to correlate the presence, prevalence and geographical distribution of endosymbionts in B. tabaci. Phylogenies 5 were constructed to track evolutionary differences amongst the endosymbionts and insects and how they have influenced the evolution of the regional populations. Samples were characterized by differences in the genomes and endosymbionts of common whitefly ‘biotypes’ that have different host plant preferences, vector capacities and insecticide resistance characteristics. It was found that the B biotype is the predominant haplotype, with no evidence of

  4. 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.

  5. Evolutionary convergence and nitrogen metabolism in Blattabacterium strain Bge, primary endosymbiont of the cockroach Blattella germanica.

    Directory of Open Access Journals (Sweden)

    Maria J López-Sánchez

    2009-11-01

    Full Text Available Bacterial endosymbionts of insects play a central role in upgrading the diet of their hosts. In certain cases, such as aphids and tsetse flies, endosymbionts complement the metabolic capacity of hosts living on nutrient-deficient diets, while the bacteria harbored by omnivorous carpenter ants are involved in nitrogen recycling. In this study, we describe the genome sequence and inferred metabolism of Blattabacterium strain Bge, the primary Flavobacteria endosymbiont of the omnivorous German cockroach Blattella germanica. Through comparative genomics with other insect endosymbionts and free-living Flavobacteria we reveal that Blattabacterium strain Bge shares the same distribution of functional gene categories only with Blochmannia strains, the primary Gamma-Proteobacteria endosymbiont of carpenter ants. This is a remarkable example of evolutionary convergence during the symbiotic process, involving very distant phylogenetic bacterial taxa within hosts feeding on similar diets. Despite this similarity, different nitrogen economy strategies have emerged in each case. Both bacterial endosymbionts code for urease but display different metabolic functions: Blochmannia strains produce ammonia from dietary urea and then use it as a source of nitrogen, whereas Blattabacterium strain Bge codes for the complete urea cycle that, in combination with urease, produces ammonia as an end product. Not only does the cockroach endosymbiont play an essential role in nutrient supply to the host, but also in the catabolic use of amino acids and nitrogen excretion, as strongly suggested by the stoichiometric analysis of the inferred metabolic network. Here, we explain the metabolic reasons underlying the enigmatic return of cockroaches to the ancestral ammonotelic state.

  6. Evolutionary Convergence and Nitrogen Metabolism in Blattabacterium strain Bge, Primary Endosymbiont of the Cockroach Blattella germanica

    Science.gov (United States)

    López-Sánchez, Maria J.; Neef, Alexander; Peretó, Juli; Patiño-Navarrete, Rafael; Pignatelli, Miguel; Latorre, Amparo; Moya, Andrés

    2009-01-01

    Bacterial endosymbionts of insects play a central role in upgrading the diet of their hosts. In certain cases, such as aphids and tsetse flies, endosymbionts complement the metabolic capacity of hosts living on nutrient-deficient diets, while the bacteria harbored by omnivorous carpenter ants are involved in nitrogen recycling. In this study, we describe the genome sequence and inferred metabolism of Blattabacterium strain Bge, the primary Flavobacteria endosymbiont of the omnivorous German cockroach Blattella germanica. Through comparative genomics with other insect endosymbionts and free-living Flavobacteria we reveal that Blattabacterium strain Bge shares the same distribution of functional gene categories only with Blochmannia strains, the primary Gamma-Proteobacteria endosymbiont of carpenter ants. This is a remarkable example of evolutionary convergence during the symbiotic process, involving very distant phylogenetic bacterial taxa within hosts feeding on similar diets. Despite this similarity, different nitrogen economy strategies have emerged in each case. Both bacterial endosymbionts code for urease but display different metabolic functions: Blochmannia strains produce ammonia from dietary urea and then use it as a source of nitrogen, whereas Blattabacterium strain Bge codes for the complete urea cycle that, in combination with urease, produces ammonia as an end product. Not only does the cockroach endosymbiont play an essential role in nutrient supply to the host, but also in the catabolic use of amino acids and nitrogen excretion, as strongly suggested by the stoichiometric analysis of the inferred metabolic network. Here, we explain the metabolic reasons underlying the enigmatic return of cockroaches to the ancestral ammonotelic state. PMID:19911043

  7. 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

  8. Sinorhizobium meliloti sigma factors RpoE1 and RpoE4 are activated in stationary phase in response to sulfite.

    Directory of Open Access Journals (Sweden)

    Bénédicte Bastiat

    Full Text Available Rhizobia are soil bacteria able to establish a nitrogen-fixing symbiosis with legume plants. Both in soil and in planta, rhizobia spend non-growing periods resembling the stationary phase of in vitro-cultured bacteria. The primary objective of this work was to better characterize gene regulation in this biologically relevant growth stage in Sinorhizobium meliloti. By a tap-tag/mass spectrometry approach, we identified five sigma factors co-purifying with the RNA polymerase in stationary phase: the general stress response regulator RpoE2, the heat shock sigma factor RpoH2, and three extra-cytoplasmic function sigma factors (RpoE1, RpoE3 and RpoE4 belonging to the poorly characterized ECF26 subgroup. We then showed that RpoE1 and RpoE4 i are activated upon metabolism of sulfite-generating compounds (thiosulfate and taurine, ii display overlapping regulatory activities, iii govern a dedicated sulfite response by controlling expression of the sulfite dehydrogenase SorT, iv are activated in stationary phase, likely as a result of endogenous sulfite generation during bacterial growth. We showed that SorT is required for optimal growth of S. meliloti in the presence of sulfite, suggesting that the response governed by RpoE1 and RpoE4 may be advantageous for bacteria in stationary phase either by providing a sulfite detoxification function or by contributing to energy production through sulfite respiration. This paper therefore reports the first characterization of ECF26 sigma factors, the first description of sigma factors involved in control of sulphur metabolism, and the first indication that endogenous sulfite may act as a signal for regulation of gene expression upon entry of bacteria in stationary phase.

  9. [The effect of combined and separate inoculation of alfalfa plants with Azospirillum lipoferum and Sinorhizobium meliloti on denitrification and nitrogen-fixing activities].

    Science.gov (United States)

    Furina, E K; Bonartseva, G A

    2007-01-01

    The effects of associative nitrogen fixer Azospirillum lipoferum strain 137 and root nodule bacteria Sinorhizobium meliloti after combined and separate inoculation of alfalfa seedlings on the background of mineral nitrogen applied at various times were studied. It was demonstrated that exudates of the alfalfa seedlings with the first pair of cotyledonary leaves already provide a high activity of these bacteria in the rhizosphere. To 74.6% of the introduced nitrate was transformed into N2O when the binary preparation of these bacteria was used. In an extended experiment (30 days), an active reduction of nitrates to N2O (11 micromol N2O/pot x 24 h) with inhibition of nitrogen fixation was observed in all of the experimental variants during the formation of legume-rhizobial and associative symbioses and simultaneous introduction of nitrates and bacteria. The most active enzyme fixation was observed in the case of a late (after 14 days) application of nitrates in the variants with both separate inoculations and inoculation with the binary preparation of A. lipoferum and S. meliloti. Separation in time of the application of bacterial preparations and mineral nitrogen assisted its preservation in all of the experimental variants. The variant of alfalfa inoculation with the binary preparation of A. lipoferum and S. meliloti and application of nitrates 2 weeks after inoculation was optimal for active nitrogen fixation (224.7 C2H4 nmol/flask x 24 h) and low denitrification activity (1.8 x micromol N2O/flask x 24 h). These results are useful in applied developments aimed at the use of bacterial and mineral fertilizers for leguminous plants.

  10. Plants, endosymbionts and parasites: Abscisic acid and calcium signaling.

    Science.gov (United States)

    Nagamune, Kisaburo; Xiong, Liming; Chini, Eduardo; Sibley, L David

    2008-01-01

    It was recently discovered that the protozoan parasite, Toxoplasma gondii produces and uses the plant hormone, abscisic acid (ABA), for communication. Following intracellular replication, ABA production influences the timing of parasite egress from the host cell. This density-dependent signal may serve to coordinate exit from the host cell in a synchronous manner by triggering calcium-dependent activation of motility. In the absence of ABA production, parasites undergo differentiation to the semidormant, tissue cyst. The pathway for ABA production in T. gondii may be derived from a relict endosymbiont, acquired by ingestion of a red algal cell. Although the parasite has lost the capacity for photosynthesis, the plant-like nature of this signaling pathway may be exploited to develop new drugs. In support of this idea, an inhibitor of ABA biosynthesis protected mice against lethal infection with T. gondii. Here, we compare the role of ABA in parasites to its activities in plants, where it is know to control development and stress responses.

  11. Two ancient bacterial endosymbionts have coevolved with the planthoppers (Insecta: Hemiptera: Fulgoroidea

    Directory of Open Access Journals (Sweden)

    Urban Julie M

    2012-06-01

    Full Text Available Abstract Background Members of the hemipteran suborder Auchenorrhyncha (commonly known as planthoppers, tree- and leafhoppers, spittlebugs, and cicadas are unusual among insects known to harbor endosymbiotic bacteria in that they are associated with diverse assemblages of bacterial endosymbionts. Early light microscopic surveys of species representing the two major lineages of Auchenorrhyncha (the planthopper superfamily Fulgoroidea; and Cicadomorpha, comprising Membracoidea [tree- and leafhoppers], Cercopoidea [spittlebugs], and Cicadoidea [cicadas], found that most examined species harbored at least two morphologically distinct bacterial endosymbionts, and some harbored as many as six. Recent investigations using molecular techniques have identified multiple obligate bacterial endosymbionts in Cicadomorpha; however, much less is known about endosymbionts of Fulgoroidea. In this study, we present the initial findings of an ongoing PCR-based survey (sequencing 16S rDNA of planthopper-associated bacteria to document endosymbionts with a long-term history of codiversification with their fulgoroid hosts. Results Results of PCR surveys and phylogenetic analyses of 16S rDNA recovered a monophyletic clade of Betaproteobacteria associated with planthoppers; this clade included Vidania fulgoroideae, a recently described bacterium identified in exemplars of the planthopper family Cixiidae. We surveyed 77 planthopper species representing 18 fulgoroid families, and detected Vidania in 40 species (representing 13 families. Further, we detected the Sulcia endosymbiont (identified as an obligate endosymbiont of Auchenorrhyncha in previous studies in 30 of the 40 species harboring Vidania. Concordance of the Vidania phylogeny with the phylogeny of the planthopper hosts (reconstructed based on sequence data from five genes generated from the same insect specimens from which the bacterial sequences were obtained was supported by statistical tests of

  12. Two ancient bacterial endosymbionts have coevolved with the planthoppers (Insecta: Hemiptera: Fulgoroidea).

    Science.gov (United States)

    Urban, Julie M; Cryan, Jason R

    2012-06-14

    Members of the hemipteran suborder Auchenorrhyncha (commonly known as planthoppers, tree- and leafhoppers, spittlebugs, and cicadas) are unusual among insects known to harbor endosymbiotic bacteria in that they are associated with diverse assemblages of bacterial endosymbionts. Early light microscopic surveys of species representing the two major lineages of Auchenorrhyncha (the planthopper superfamily Fulgoroidea; and Cicadomorpha, comprising Membracoidea [tree- and leafhoppers], Cercopoidea [spittlebugs], and Cicadoidea [cicadas]), found that most examined species harbored at least two morphologically distinct bacterial endosymbionts, and some harbored as many as six. Recent investigations using molecular techniques have identified multiple obligate bacterial endosymbionts in Cicadomorpha; however, much less is known about endosymbionts of Fulgoroidea. In this study, we present the initial findings of an ongoing PCR-based survey (sequencing 16S rDNA) of planthopper-associated bacteria to document endosymbionts with a long-term history of codiversification with their fulgoroid hosts. Results of PCR surveys and phylogenetic analyses of 16S rDNA recovered a monophyletic clade of Betaproteobacteria associated with planthoppers; this clade included Vidania fulgoroideae, a recently described bacterium identified in exemplars of the planthopper family Cixiidae. We surveyed 77 planthopper species representing 18 fulgoroid families, and detected Vidania in 40 species (representing 13 families). Further, we detected the Sulcia endosymbiont (identified as an obligate endosymbiont of Auchenorrhyncha in previous studies) in 30 of the 40 species harboring Vidania. Concordance of the Vidania phylogeny with the phylogeny of the planthopper hosts (reconstructed based on sequence data from five genes generated from the same insect specimens from which the bacterial sequences were obtained) was supported by statistical tests of codiversification. Codiversification tests also

  13. Genome Evolution and Phylogenomic Analysis of Candidatus Kinetoplastibacterium, the Betaproteobacterial Endosymbionts of Strigomonas and Angomonas

    Science.gov (United States)

    Alves, João M.P.; Serrano, Myrna G.; Maia da Silva, Flávia; Voegtly, Logan J.; Matveyev, Andrey V.; Teixeira, Marta M.G.; Camargo, Erney P.; Buck, Gregory A.

    2013-01-01

    It has been long known that insect-infecting trypanosomatid flagellates from the genera Angomonas and Strigomonas harbor bacterial endosymbionts (Candidatus Kinetoplastibacterium or TPE [trypanosomatid proteobacterial endosymbiont]) that supplement the host metabolism. Based on previous analyses of other bacterial endosymbiont genomes from other lineages, a stereotypical path of genome evolution in such bacteria over the duration of their association with the eukaryotic host has been characterized. In this work, we sequence and analyze the genomes of five TPEs, perform their metabolic reconstruction, do an extensive phylogenomic analyses with all available Betaproteobacteria, and compare the TPEs with their nearest betaproteobacterial relatives. We also identify a number of housekeeping and central metabolism genes that seem to have undergone positive selection. Our genome structure analyses show total synteny among the five TPEs despite millions of years of divergence, and that this lineage follows the common path of genome evolution observed in other endosymbionts of diverse ancestries. As previously suggested by cell biology and biochemistry experiments, Ca. Kinetoplastibacterium spp. preferentially maintain those genes necessary for the biosynthesis of compounds needed by their hosts. We have also shown that metabolic and informational genes related to the cooperation with the host are overrepresented amongst genes shown to be under positive selection. Finally, our phylogenomic analysis shows that, while being in the Alcaligenaceae family of Betaproteobacteria, the closest relatives of these endosymbionts are not in the genus Bordetella as previously reported, but more likely in the Taylorella genus. PMID:23345457

  14. Serratia symbiotica from the aphid Cinara cedri: a missing link from facultative to obligate insect endosymbiont.

    Directory of Open Access Journals (Sweden)

    Araceli Lamelas

    2011-11-01

    Full Text Available The genome sequencing of Buchnera aphidicola BCc from the aphid Cinara cedri, which is the smallest known Buchnera genome, revealed that this bacterium had lost its symbiotic role, as it was not able to synthesize tryptophan and riboflavin. Moreover, the biosynthesis of tryptophan is shared with the endosymbiont Serratia symbiotica SCc, which coexists with B. aphidicola in this aphid. The whole-genome sequencing of S. symbiotica SCc reveals an endosymbiont in a stage of genome reduction that is closer to an obligate endosymbiont, such as B. aphidicola from Acyrthosiphon pisum, than to another S. symbiotica, which is a facultative endosymbiont in this aphid, and presents much less gene decay. The comparison between both S. symbiotica enables us to propose an evolutionary scenario of the transition from facultative to obligate endosymbiont. Metabolic inferences of B. aphidicola BCc and S. symbiotica SCc reveal that most of the functions carried out by B. aphidicola in A. pisum are now either conserved in B. aphidicola BCc or taken over by S. symbiotica. In addition, there are several cases of metabolic complementation giving functional stability to the whole consortium and evolutionary preservation of the actors involved.

  15. An effective molecular approach for assessing cereal aphid-parasitoid-endosymbiont networks.

    Science.gov (United States)

    Ye, Zhengpei; Vollhardt, Ines M G; Girtler, Susanne; Wallinger, Corinna; Tomanovic, Zeljko; Traugott, Michael

    2017-06-09

    Molecular approaches are increasingly being used to analyse host-parasitoid food webs as they overcome several hurdles inherent to conventional approaches. However, such studies have focused primarily on the detection and identification of aphids and their aphidiid primary parasitoids, largely ignoring primary parasitoid-hyperparasitoid interactions or limiting these to a few common species within a small geographical area. Furthermore, the detection of bacterial secondary endosymbionts has not been considered in such assays despite the fact that endosymbionts may alter aphid-parasitoid interactions, as they can confer protection against parasitoids. Here we present a novel two-step multiplex PCR (MP-PCR) protocol to assess cereal aphid-primary parasitoid-hyperparasitoid-endosymbiont interactions. The first step of the assay allows detection of parasitoid DNA at a general level (24 primary and 16 hyperparasitoid species) as well as the species-specific detection of endosymbionts (3 species) and cereal aphids (3 species). The second step of the MP-PCR assay targets seven primary and six hyperparasitoid species that commonly occur in Central Europe. Additional parasitoid species not covered by the second-step of the assay can be identified via sequencing 16S rRNA amplicons generated in the first step of the assay. The approach presented here provides an efficient, highly sensitive, and cost-effective (~consumable costs of 1.3 € per sample) tool for assessing cereal aphid-parasitoid-endosymbiont interactions.

  16. Endosymbiont-based immunity in Drosophila melanogaster against parasitic nematode infection.

    Science.gov (United States)

    Yadav, Shruti; Frazer, Joanna; Banga, Ashima; Pruitt, Katherine; Harsh, Sneh; Jaenike, John; Eleftherianos, Ioannis

    2018-01-01

    Associations between endosymbiotic bacteria and their hosts represent a complex ecosystem within organisms ranging from humans to protozoa. Drosophila species are known to naturally harbor Wolbachia and Spiroplasma endosymbionts, which play a protective role against certain microbial infections. Here, we investigated whether the presence or absence of endosymbionts affects the immune response of Drosophila melanogaster larvae to infection by Steinernema carpocapsae nematodes carrying or lacking their mutualistic Gram-negative bacteria Xenorhabdus nematophila (symbiotic or axenic nematodes, respectively). We find that the presence of Wolbachia alone or together with Spiroplasma promotes the survival of larvae in response to infection with S. carpocapsae symbiotic nematodes, but not against axenic nematodes. We also find that Wolbachia numbers are reduced in Spiroplasma-free larvae infected with axenic compared to symbiotic nematodes, and they are also reduced in Spiroplasma-containing compared to Spiroplasma-free larvae infected with axenic nematodes. We further show that S. carpocapsae axenic nematode infection induces the Toll pathway in the absence of Wolbachia, and that symbiotic nematode infection leads to increased phenoloxidase activity in D. melanogaster larvae devoid of endosymbionts. Finally, infection with either type of nematode alters the metabolic status and the fat body lipid droplet size in D. melanogaster larvae containing only Wolbachia or both endosymbionts. Our results suggest an interaction between Wolbachia endosymbionts with the immune response of D. melanogaster against infection with the entomopathogenic nematodes S. carpocapsae. Results from this study indicate a complex interplay between insect hosts, endosymbiotic microbes and pathogenic organisms.

  17. Occurrence of bacterial endosymbionts in Acanthamoeba spp. isolated from corneal and environmental specimens and contact lenses.

    Science.gov (United States)

    Fritsche, T R; Gautom, R K; Seyedirashti, S; Bergeron, D L; Lindquist, T D

    1993-01-01

    Free-living and parasitic protozoa are known to harbor a variety of endosymbiotic bacteria, although the roles such endosymbionts play in host survival, infectivity, and invasiveness are unclear. We have identified the presence of intracellular bacteria in 14 of 57 (24%) axenically grown Acanthamoeba isolates examined. These organisms are gram negative and non-acid fast, and they cannot be cultured by routine methodologies, although electron microscopy reveals evidence for multiplication within the amoebic cytoplasm. Examination for Legionella spp. with culture and nucleic acid probes has proven unsuccessful. We conclude that these bacteria are endosymbionts which have an obligate need to multiply within their amoebic hosts. Rod-shaped bacteria were identified in 5 of 23 clinical Acanthamoeba isolates (3 of 19 corneal isolates and 2 of 4 contact lens isolates), 4 of 25 environmental Acanthamoeba isolates, and 2 of 9 American Type Culture Collection Acanthamoeba isolates (ATCC 30868 and ATCC 30871) previously unrecognized as having endosymbionts. Coccus-shaped bacteria were present in one clinical (corneal) isolate and two environmental isolates. There was no statistical difference (P > 0.8) between the numbers of endosymbiont strains originating from clinical (26% positive) and environmental (24% positive) amoebic isolates, suggesting that the presence alone of these bacteria does not enhance amoebic infectivity. Rods and cocci were found in both clinical and environmental isolates from different geographical areas (Seattle, Wash., and Portland, Oreg.), demonstrating their widespread occurrence in nature. Our findings suggest that endosymbiosis occurs commonly among members of the family Acanthamoebidae and that the endosymbionts comprise a diverse taxonomic assemblage. The role such endosymbionts may play in pathogenesis remains unknown, although a variety of exogenous bacteria have been implicated in the development of amoebic keratitis, warranting further

  18. 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.

  19. 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

  20. The Role of Lipid Competition for Endosymbiont-Mediated Protection against Parasitoid Wasps in Drosophila.

    Science.gov (United States)

    Paredes, Juan C; Herren, Jeremy K; Schüpfer, Fanny; Lemaitre, Bruno

    2016-07-12

    Insects commonly harbor facultative bacterial endosymbionts, such as Wolbachia and Spiroplasma species, that are vertically transmitted from mothers to their offspring. These endosymbiontic bacteria increase their propagation by manipulating host reproduction or by protecting their hosts against natural enemies. While an increasing number of studies have reported endosymbiont-mediated protection, little is known about the mechanisms underlying this protection. Here, we analyze the mechanisms underlying protection from parasitoid wasps in Drosophila melanogaster mediated by its facultative endosymbiont Spiroplasma poulsonii Our results indicate that S. poulsonii exerts protection against two distantly related wasp species, Leptopilina boulardi and Asobara tabida S. poulsonii-mediated protection against parasitoid wasps takes place at the pupal stage and is not associated with an increased cellular immune response. In this work, we provide three important observations that support the notion that S. poulsonii bacteria and wasp larvae compete for host lipids and that this competition underlies symbiont-mediated protection. First, lipid quantification shows that both S. poulsonii and parasitoid wasps deplete D. melanogaster hemolymph lipids. Second, the depletion of hemolymphatic lipids using the Lpp RNA interference (Lpp RNAi) construct reduces wasp success in larvae that are not infected with S. poulsonii and blocks S. poulsonii growth. Third, we show that the growth of S. poulsonii bacteria is not affected by the presence of the wasps, indicating that when S. poulsonii is present, larval wasps will develop in a lipid-depleted environment. We propose that competition for host lipids may be relevant to endosymbiont-mediated protection in other systems and could explain the broad spectrum of protection provided. Virtually all insects, including crop pests and disease vectors, harbor facultative bacterial endosymbionts. They are vertically transmitted from mothers to

  1. The Sinorhizobium fredii HH103 MucR1 Global Regulator Is Connected With the nod Regulon and Is Required for Efficient Symbiosis With Lotus burttii and Glycine max cv. Williams.

    Science.gov (United States)

    Acosta-Jurado, Sebastián; Alias-Villegas, Cynthia; Navarro-Gómez, Pilar; Zehner, Susanne; Murdoch, Piedad Del Socorro; Rodríguez-Carvajal, Miguel A; Soto, María J; Ollero, Francisco-Javier; Ruiz-Sainz, José E; Göttfert, Michael; Vinardell, José-María

    2016-09-01

    Sinorhizobium fredii HH103 is a rhizobial strain showing a broad host range of nodulation. In addition to the induction of bacterial nodulation genes, transition from a free-living to a symbiotic state requires complex genetic expression changes with the participation of global regulators. We have analyzed the role of the zinc-finger transcriptional regulator MucR1 from S. fredii HH103 under both free-living conditions and symbiosis with two HH103 host plants, Glycine max and Lotus burttii. Inactivation of HH103 mucR1 led to a severe decrease in exopolysaccharide (EPS) biosynthesis but enhanced production of external cyclic glucans (CG). This mutant also showed increased cell aggregation capacity as well as a drastic reduction in nitrogen-fixation capacity with G. max and L. burttii. However, in these two legumes, the number of nodules induced by the mucR1 mutant was significantly increased and decreased, respectively, with respect to the wild-type strain, indicating that MucR1 can differently affect nodulation depending on the host plant. RNA-Seq analysis carried out in the absence and the presence of flavonoids showed that MucR1 controls the expression of hundreds of genes (including some related to EPS production and CG transport), some of them being related to the nod regulon.

  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. A nopA deletion mutant of Sinorhizobium fredii USDA257, a soybean symbiont, is impaired in nodulation

    Science.gov (United States)

    Sinorhizobium fredii USDA257 employs type III secretion system (T3SS) to deliver effector proteins into the host cells through filamentous surface appendages, called pili. The NopA protein is the major component of USDA257 pili. The promoter region of USDA257 nopA posses a well conserved tts box. Se...

  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. 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)

  7. 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 ...

  8. 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 ...

  9. 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.

  10. Diversifying selection and host adaptation in two endosymbiont genomes

    Directory of Open Access Journals (Sweden)

    Slatko Barton

    2007-04-01

    Full Text Available Abstract Background The endosymbiont Wolbachia pipientis infects a broad range of arthropod and filarial nematode hosts. These diverse associations form an attractive model for understanding host:symbiont coevolution. Wolbachia's ubiquity and ability to dramatically alter host reproductive biology also form the foundation of research strategies aimed at controlling insect pests and vector-borne disease. The Wolbachia strains that infect nematodes are phylogenetically distinct, strictly vertically transmitted, and required by their hosts for growth and reproduction. Insects in contrast form more fluid associations with Wolbachia. In these taxa, host populations are most often polymorphic for infection, horizontal transmission occurs between distantly related hosts, and direct fitness effects on hosts are mild. Despite extensive interest in the Wolbachia system for many years, relatively little is known about the molecular mechanisms that mediate its varied interactions with different hosts. We have compared the genomes of the Wolbachia that infect Drosophila melanogaster, wMel and the nematode Brugia malayi, wBm to that of an outgroup Anaplasma marginale to identify genes that have experienced diversifying selection in the Wolbachia lineages. The goal of the study was to identify likely molecular mechanisms of the symbiosis and to understand the nature of the diverse association across different hosts. Results The prevalence of selection was far greater in wMel than wBm. Genes contributing to DNA metabolism, cofactor biosynthesis, and secretion were positively selected in both lineages. In wMel there was a greater emphasis on DNA repair, cell division, protein stability, and cell envelope synthesis. Conclusion Secretion pathways and outer surface protein encoding genes are highly affected by selection in keeping with host:parasite theory. If evidence of selection on various cofactor molecules reflects possible provisioning, then both insect as

  11. Kentomonas gen. n., a New Genus of Endosymbiont-containing Trypanosomatids of Strigomonadinae subfam. n

    Czech Academy of Sciences Publication Activity Database

    Votýpka, Jan; Kostygov, A.Y.; Kraeva, N.; Grybchuk-Ieremenko, A.; Tesařová, Martina; Grybchuk, D.; Lukeš, Julius; Yurchenko, Vyacheslav

    2014-01-01

    Roč. 165, č. 6 (2014), s. 825-838 ISSN 1434-4610 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Kentomonas * Trypanosomatidae * bacterial endosymbionts * phylogeny Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.045, year: 2014

  12. Establishment and maintenance of aphid endosymbionts after horizontal transfer is dependent on host genotype

    Czech Academy of Sciences Publication Activity Database

    Parker, B. J.; McLean, A. H. C.; Hrček, Jan; Gerardo, N. M.; Godfray, H. C. J.

    2017-01-01

    Roč. 13, č. 5 (2017), č. článku 20170016. ISSN 1744-9561 Institutional support: RVO:60077344 Keywords : endosymbionts * horizontal transfer * pea aphid Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 3.089, year: 2016 http://rsbl.royalsocietypublishing.org/content/13/5/20170016.long

  13. Species and endosymbiont diversity of Bemisia tabaci (Homoptera: Aleyrodidae) on vegetable crops in Senegal.

    Science.gov (United States)

    Hélène, Delatte; Rémy, Baudin; Nathalie, Becker; Anne-Laure, Girard; Traoré, Ramatoulaye Sidebe; Jean-Michel, Lett; Bernard, Reynaud

    2015-03-01

    Bemisia tabaci-transmitted geminiviruses are one of the major threats on cassava and vegetable crops in Africa. However, to date, few studies are available on the diversity of B. tabaci and their associated endosymbionts in Africa. More than 28 species have been described in the complex of B. tabaci cryptic species; among them, 2 are invasive pests worldwide: MED and MEAM1. In order to assess the species diversity of B. tabaci in vegetable crops in Senegal, several samplings in different localities, hosts and seasons were collected and analyzed with nuclear (microsatellite) and mitochondrial (COI) markers. The bacterial endosymbiont community was also studied for each sample. Two species were detected: MED Q1 and MEAM1 B. Patterns of MED Q1 (dominance on most of the samples and sites, highest nuclear and mitochondrial diversity and broader secondary endosymbiont community: Hamiltonella, Cardinium, Wolbachia and Rickettsia), point toward a predominant resident begomovirus vector group for MED Q1 on market gardening crops. Furthermore, the lower prevalence of the second species MEAM1 B, its lower nuclear and mitochondrial diversity and a narrower secondary endosymbiont community (Hamiltonella/Rickettsia), indicate that this genetic group is exotic and results from a recent invasion in this area. © 2014 Institute of Zoology, Chinese Academy of Sciences.

  14. Diversity and localization of bacterial endosymbionts from whitefly species collected in Brazil.

    Science.gov (United States)

    Marubayashi, Julio Massaharu; Kliot, Adi; Yuki, Valdir Atsushi; Rezende, Jorge Alberto Marques; Krause-Sakate, Renate; Pavan, Marcelo Agenor; Ghanim, Murad

    2014-01-01

    Whiteflies (Hemiptera: Aleyrodidae) are sap-sucking insect pests, and some cause serious damage in agricultural crops by direct feeding and by transmitting plant viruses. Whiteflies maintain close associations with bacterial endosymbionts that can significantly influence their biology. All whitefly species harbor a primary endosymbiont, and a diverse array of secondary endosymbionts. In this study, we surveyed 34 whitefly populations collected from the states of Sao Paulo, Bahia, Minas Gerais and Parana in Brazil, for species identification and for infection with secondary endosymbionts. Sequencing the mitochondrial Cytochrome Oxidase I gene revealed the existence of five whitefly species: The sweetpotato whitefly Bemisia tabaci B biotype (recently termed Middle East-Asia Minor 1 or MEAM1), the greenhouse whitefly Trialeurodes vaporariorum, B. tabaci A biotype (recently termed New World 2 or NW2) collected only from Euphorbia, the Acacia whitefly Tetraleurodes acaciae and Bemisia tuberculata both were detected only on cassava. Sequencing rRNA genes showed that Hamiltonella and Rickettsia were highly prevalent in all MEAM1 populations, while Cardinium was close to fixation in only three populations. Surprisingly, some MEAM1 individuals and one NW2 population were infected with Fritschea. Arsenopnohus was the only endosymbiont detected in T. vaporariorum. In T. acaciae and B. tuberculata populations collected from cassava, Wolbachia was fixed in B. tuberculata and was highly prevalent in T. acaciae. Interestingly, while B. tuberculata was additionally infected with Arsenophonus, T. acaciae was infected with Cardinium and Fritschea. Fluorescence in situ hybridization analysis on representative individuals showed that Hamiltonella, Arsenopnohus and Fritschea were localized inside the bacteriome, Cardinium and Wolbachia exhibited dual localization patterns inside and outside the bacteriome, and Rickettsia showed strict localization outside the bacteriome. This study is

  15. The Role of Lipid Competition for Endosymbiont-Mediated Protection against Parasitoid Wasps in Drosophila

    Directory of Open Access Journals (Sweden)

    Juan C. Paredes

    2016-07-01

    Full Text Available Insects commonly harbor facultative bacterial endosymbionts, such as Wolbachia and Spiroplasma species, that are vertically transmitted from mothers to their offspring. These endosymbiontic bacteria increase their propagation by manipulating host reproduction or by protecting their hosts against natural enemies. While an increasing number of studies have reported endosymbiont-mediated protection, little is known about the mechanisms underlying this protection. Here, we analyze the mechanisms underlying protection from parasitoid wasps in Drosophila melanogaster mediated by its facultative endosymbiont Spiroplasma poulsonii. Our results indicate that S. poulsonii exerts protection against two distantly related wasp species, Leptopilina boulardi and Asobara tabida. S. poulsonii-mediated protection against parasitoid wasps takes place at the pupal stage and is not associated with an increased cellular immune response. In this work, we provide three important observations that support the notion that S. poulsonii bacteria and wasp larvae compete for host lipids and that this competition underlies symbiont-mediated protection. First, lipid quantification shows that both S. poulsonii and parasitoid wasps deplete D. melanogaster hemolymph lipids. Second, the depletion of hemolymphatic lipids using the Lpp RNA interference (Lpp RNAi construct reduces wasp success in larvae that are not infected with S. poulsonii and blocks S. poulsonii growth. Third, we show that the growth of S. poulsonii bacteria is not affected by the presence of the wasps, indicating that when S. poulsonii is present, larval wasps will develop in a lipid-depleted environment. We propose that competition for host lipids may be relevant to endosymbiont-mediated protection in other systems and could explain the broad spectrum of protection provided.

  16. A Coxiella-Like Endosymbiont Is a Potential Vitamin Source for the Lone Star Tick

    Science.gov (United States)

    Smith, Todd A; Driscoll, Timothy; Gillespie, Joseph J; Raghavan, Rahul

    2015-01-01

    Amblyomma americanum (Lone star tick) is an important disease vector in the United States. It transmits several human pathogens, including the agents of human monocytic ehrlichiosis, tularemia, and southern tick-associated rash illness. Blood-feeding insects (Class Insecta) depend on bacterial endosymbionts to provide vitamins and cofactors that are scarce in blood. It is unclear how this deficiency is compensated in ticks (Class Arachnida) that feed exclusively on mammalian blood. A bacterium related to Coxiella burnetii, the agent of human Q fever, has been observed previously within cells of A. americanum. Eliminating this bacterium (CLEAA, Coxiella-like endosymbiont of A. americanum) with antibiotics reduced tick fecundity, indicating that it is an essential endosymbiont. In an effort to determine its role within this symbiosis, we sequenced the CLEAA genome. While highly reduced (656,901 bp) compared with C. burnetii (1,995,281 bp), the CLEAA genome encodes most major vitamin and cofactor biosynthesis pathways, implicating CLEAA as a vitamin provisioning endosymbiont. In contrast, CLEAA lacks any recognizable virulence genes, indicating that it is not a pathogen despite its presence in tick salivary glands. As both C. burnetii and numerous “Coxiella-like bacteria” have been reported from several species of ticks, we determined the evolutionary relationship between the two bacteria. Phylogeny estimation revealed that CLEAA is a close relative of C. burnetii, but was not derived from it. Our results are important for strategies geared toward controlling A. americanum and the pathogens it vectors, and also contribute novel information regarding the metabolic interdependencies of ticks and their nutrient-provisioning endosymbionts. PMID:25618142

  17. The conjugative plasmid of a bean-nodulating Sinorhizobium fredii strain is assembled from sequences of two Rhizobium plasmids and the chromosome of a Sinorhizobium strain

    Directory of Open Access Journals (Sweden)

    Brom Susana

    2011-06-01

    Full Text Available Abstract Background Bean-nodulating Rhizobium etli originated in Mesoamerica, while soybean-nodulating Sinorhizobium fredii evolved in East Asia. S. fredii strains, such as GR64, have been isolated from bean nodules in Spain, suggesting the occurrence of conjugative transfer events between introduced and native strains. In R. etli CFN42, transfer of the symbiotic plasmid (pRet42d requires cointegration with the endogenous self-transmissible plasmid pRet42a. Aiming at further understanding the generation of diversity among bean nodulating strains, we analyzed the plasmids of S. fredii GR64: pSfr64a and pSfr64b (symbiotic plasmid. Results The conjugative transfer of the plasmids of strain GR64 was analyzed. Plasmid pSfr64a was self-transmissible, and required for transfer of the symbiotic plasmid. We sequenced pSfr64a, finding 166 ORFs. pSfr64a showed three large segments of different evolutionary origins; the first one presented 38 ORFs that were highly similar to genes located on the chromosome of Sinorhizobium strain NGR234; the second one harbored 51 ORFs with highest similarity to genes from pRet42d, including the replication, but not the symbiosis genes. Accordingly, pSfr64a was incompatible with the R. etli CFN42 symbiotic plasmid, but did not contribute to symbiosis. The third segment contained 36 ORFs with highest similarity to genes localized on pRet42a, 20 of them involved in conjugative transfer. Plasmid pRet42a was unable to substitute pSfr64a for induction of pSym transfer, and its own transfer was significantly diminished in GR64 background. The symbiotic plasmid pSfr64b was found to differ from typical R. etli symbiotic plasmids. Conclusions S. fredii GR64 contains a chimeric transmissible plasmid, with segments from two R. etli plasmids and a S. fredii chromosome, and a symbiotic plasmid different from the one usually found in R. etli bv phaseoli. We infer that these plasmids originated through the transfer of a symbiotic

  18. Three way interactions between Thymus vulgaris, Medicago truncatula and Sinorhizobium meliloti

    DEFF Research Database (Denmark)

    Grøndahl, Eva; Ehlers, Bodil Kirstine

    2012-01-01

    thyme communities; in fact they often grow very close to thyme plants (within 1 square meter). Medicago has a symbiosis with the nitrogen fixing bacteria Sinorhizobium meliloti – which is essential for nitrogen uptake in the nutrient poor garrigue. The aim of this study was to examine 1) if Medicago...... experienced ones, irrespective of whether the soil was amended with thyme oil or not. Furthermore, there was a small, but significant difference in Medicago fitness between naive and experienced plant genotypes on soil amended with thyme oil. Thyme experienced Medicago genotypes performed better on thyme soil......Thymus vulgaris is a dominating component of the Mediterranean garrigue vegetation. It produces aromatic oil, containing monoterpenes, which affects the performance (growth, survival) of other plants, and microorganisms. Annual plant species of the genus Medicago are commonly found in Mediterranean...

  19. Symbiotic Properties of Sinorhizobium Fredii, J-TGS50 an Indonesian Soybean Nodule Forming Bacteria

    International Nuclear Information System (INIS)

    Setiyo Hadi Waluyo

    2004-01-01

    Green House experiments were conducted to study symbiotic properties of Sinorhizobium Fredii, J-TGS50. Sinorhizobium Fredii USDA 192, USDA 201, USDA 205, USDA 206, USDA 217 and Bradyrhizobium japonicum USDA 110 were used as references. Yeast extract mannitol broth culture of the bacteria were made and used as inoculation for several local and imported soybean varieties used in this study. Plants were harvested at 20 days after inoculation. Number of nodules were counted, fresh weight of nodules and shoot were determined. S. Fredii J-TGS50 and S. Fredii USDA 192, USDA 201, USDA 205, USDA 206, USDA 217 were found different in their symbiotic properties. S. Fredii J-TGS50 formed nodules on same imported soybean. While there were no nodules obtained from the plant inoculated with S. Fredii USDA 192, USDA 201, USDA 205, USDA 206, USDA 217. S. Fredii J-TGS50 and recommended B. Japonicum USDA 110 formed nodule on several local soybean varieties. There was no differences between those two bacteria either in nodulation efficiency or in the effectiveness of the formed nodules. Results of this study can be concluded that S. Fredii, J-TGS50 is a native to Indonesian soil and it is a promising soybean nodule forming bacteria in Indonesia. Using indigenous bacteria is valuable. Since they are mostly more tolerant and adaptable than the introduced ones. An important aspect for the success of Biological Nitrogen Fixation (BNF) is insight in the structure of indigenous soybean rhizobia populations. Study on the biodiversity of soybean rhizobia was important conducted. (author)

  20. The tep1 gene of Sinorhizobium meliloti coding for a putative transmembrane efflux protein and N-acetyl glucosamine affect nod gene expression and nodulation of alfalfa plants

    Directory of Open Access Journals (Sweden)

    Soto María

    2009-01-01

    Full Text Available Abstract Background Soil bacteria collectively known as Rhizobium, characterized by their ability to establish beneficial symbiosis with legumes, share several common characteristics with pathogenic bacteria when infecting the host plant. Recently, it was demonstrated that a fadD mutant of Sinorhizobium meliloti is altered in the control of swarming, a type of co-ordinated movement previously associated with pathogenicity, and is also impaired in nodulation efficiency on alfalfa roots. In the phytopathogen Xanthomonas campestris, a fadD homolog (rpfB forms part of a cluster of genes involved in the regulation of pathogenicity factors. In this work, we have investigated the role in swarming and symbiosis of SMc02161, a S. meliloti fadD-linked gene. Results The SMc02161 locus in S. meliloti shows similarities with members of the Major Facilitator Superfamily (MFS of transporters. A S. meliloti null-mutant shows increased sensitivity to chloramphenicol. This indication led us to rename the locus tep1 for transmembrane efflux protein. The lack of tep1 does not affect the appearance of swarming motility. Interestingly, nodule formation efficiency on alfalfa plants is improved in the tep1 mutant during the first days of the interaction though nod gene expression is lower than in the wild type strain. Curiously, a nodC mutation or the addition of N-acetyl glucosamine to the wild type strain lead to similar reductions in nod gene expression as in the tep1 mutant. Moreover, aminosugar precursors of Nod factors inhibit nodulation. Conclusion tep1 putatively encodes a transmembrane protein which can confer chloramphenicol resistance in S. meliloti by expelling the antibiotic outside the bacteria. The improved nodulation of alfalfa but reduced nod gene expression observed in the tep1 mutant suggests that Tep1 transports compounds which influence nodulation. In contrast to Bradyrhizobium japonicum, we show that in S. meliloti there is no feedback regulation

  1. 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)

  2. 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...

  3. Response of sponges with autotrophic endosymbionts during the coral-bleaching episode in Puerto Rico

    Science.gov (United States)

    Vicente, V. P.

    1990-04-01

    An updated list of sponges with algal endosymbionts including new records for Puerto Rico and the Caribbean, indicates that thirty-five species of common Caribbean sponges possess photosynthetic endosymbionts. Of these, 23 (67.6%) species in seven orders, were found with unicellular chroococcoid cyanobacteria ( Aphanocapsa-like) and 5 (14.7%) hadromerid species were found with zooxanthellae. Sponges with other algae as symbionts occur less frequently (≦6%). Thirty-one common sponge species were inspected for bleaching during coral-bleaching months (July-September 1987; January 1988) in Puerto Rico. Anthosigmella varians, Xestospongia muta and Petrosia pellasarca bleached partially, but only few individuals within any given population became bleached and the bleaching of sponges was very localized. Adaptations between cyanobacterial symbionts and sponges, acquired during the long evolutionary history of these two taxa may explain the paucity of bleached sponges when compared to the high incidence of bleached corals reported.

  4. Apple snails and their endosymbionts bioconcentrate heavy metals and uranium from contaminated drinking water.

    Science.gov (United States)

    Vega, Israel A; Arribére, María A; Almonacid, Andrea V; Ribeiro Guevara, Sergio; Castro-Vazquez, Alfredo

    2012-09-01

    The differential ability of apple snail tissues, endosymbionts, and eggs to bioaccumulate several metals (Sb, As, Ba, Br, Zn, Cr, Fe, Hg, Se, and U) was investigated. Metal concentrations were determined by neutron activation analysis in several tissues, endosymbionts, and eggs from mature apple snails cultured in either drinking water or reconstituted water (prepared with American Society for Testing and Materials type I water). The highest bioconcentration factors (BCFs) in the midgut gland were found for Ba, Zn, Se, As, U, Br, and Hg (in decreasing order), while the highest in the kidney were for Ba, Br, and Hg. The foot showed the highest BCFs for Ba, Hg, Br, and Se (in decreasing order). Calcified tissues (uterus, shell) and eggs showed low BCFs, except for Ba. Both C corpuscles and gland tissue showed statistically higher BCFs than K corpuscles for Ba, Fe, U, Br, and Sb. The concentration of most of the studied elements was significantly lower in tissues and endosymbionts obtained from snails cultured in reconstituted water instead of drinking water. Snails cultured in reconstituted water and then exposed or not to Hg, As, and U (at the maximum contaminant level allowed by the US Environmental Protection Agency) also resulted in high levels accumulated in midgut gland, endosymbionts and kidney. Our findings suggest that the midgut gland (and the symbionts contained therein), the kidney, and the foot of Pomacea canaliculata may be useful bioindicators of Hg, As and U pollution in freshwater bodies and that the unrestricted use of ampullariid snails as human and animal food must be considered with caution.

  5. 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

  6. Vertically transmitted viral endosymbionts of insects: do sigma viruses walk alone?

    Science.gov (United States)

    Longdon, Ben; Jiggins, Francis M

    2012-10-07

    Insects are host to a wide range of vertically transmitted bacterial endosymbionts, but we know relatively little about their viral counterparts. Here, we discuss the vertically transmitted viral endosymbionts of insects, firstly examining the diversity of this group, and then focusing on the well-studied sigma viruses that infect dipterans. Despite limited sampling, evidence suggests that vertically transmitted viruses may be common in insects. Unlike bacteria, viruses can be transmitted through sperm and eggs, a trait that allows them to rapidly spread through host populations even when infection is costly to the host. Work on Drosophila melanogaster has shown that sigma viruses and their hosts are engaged in a coevolutionary arms race, in which the spread of resistance genes in the host population is followed by the spread of viral genotypes that can overcome host resistance. In the long-term, associations between sigma viruses and their hosts are unstable, and the viruses persist by occasionally switching to new host species. It therefore seems likely that viral endosymbionts have major impacts on the evolution and ecology of insects.

  7. A screen of maternally inherited microbial endosymbionts in oribatid mites (Acari: Oribatida).

    Science.gov (United States)

    Konecka, Edyta; Olszanowski, Ziemowit

    2015-08-01

    We determined the distribution of microbial endosymbionts as possible agents of parthenogenesis in Oribatida. We screened mites from 20 species of 14 families suspected to be parthenogenetic from the absence or rarity of males. Our research included parthenogenesis-inducing bacteria Wolbachia spp., Cardinium spp., Rickettsia spp., and additionally Arsenophonus, Spiroplasma and microsporidia that can also manipulate host reproduction. We detected the endosymbionts by PCR-based methods and transmission electron microscopy (TEM) observation of fixed and stained preparations of host cells. We detected Wolbachia only in one Oribatida species, Oppiella nova, by identifying Wolbachia genes using PCR. TEM observations confirmed infection by the endosymbiont in O. nova and its lack in other Oribatida species. Sequence analysis of hcpA and fbpA genes showed that the Wolbachia strain from O. nova was different from strains characterized in some insects, crustaceans (Isopoda), mites (Tetranychidae), springtails (Hexapoda) and roundworms (Nematoda). The analysis strongly suggested that the Wolbachia sp. strain found in O. nova did not belong to supergroups A, B, C, D, E, F, H or M. We found that the sequences of Wolbachia from O. nova were clearly distantly related to sequences from the bacteria of the other supergroups. This observation makes O. nova a unique Wolbachia host in terms of the distinction of the strain. The role of these micro-organisms in O. nova remains unknown and is an issue to investigate.

  8. Evolutionary relationship between dinoflagellates bearing obligate diatom endosymbionts: insight into tertiary endosymbiosis.

    Science.gov (United States)

    Inagaki, Y; Dacks, J B; Doolittle, W F; Watanabe, K I; Ohama, T

    2000-11-01

    The marine dinoflagellates Peridinium balticum and Peridinium foliaceum are known for bearing diatom endosymbionts instead of peridinin-containing plastids. While evidence clearly indicates that their endosymbionts are closely related, the relationship between the host dinoflagellate cells is not settled. To examine the relationship of the two dinoflagellates, the DNA sequences of nuclear small-subunit rRNA genes (SSU rDNA) from Peridinium balticum, Peridinium foliaceum and one other peridinin-containing species, Peridinium bipes, were amplified, cloned and sequenced. While phylogenetic analyses under simple models of nucleotide substitution weakly support the monophyly of Peridinium balticum and Peridinium foliaceum, analyses under more sophisticated models significantly increased the statistical support for this relationship. Combining these results with the similarity between the two endosymbionts, it is concluded that (i) the two hosts have the closest sister relationship among dinoflagellates tested, (ii) the hypothesis that the diatom endosymbiosis occurred prior to the separation of the host cells is most likely to explain their evolutionary histories, and (iii) phylogenetic inferences under complex nucleotide evolution models seem to be able to compensate significant rate variation in the two SSU rDNA.

  9. Algal endosymbionts in European Hydra strains reflect multiple origins of the zoochlorella symbiosis.

    Science.gov (United States)

    Rajević, Nives; Kovačević, Goran; Kalafatić, Mirjana; Gould, Sven B; Martin, William F; Franjević, Damjan

    2015-12-01

    Symbiotic associations are of broad significance in evolution and biodiversity. Green Hydra is a classic example of endosymbiosis. In its gastrodermal myoepithelial cells it harbors endosymbiotic unicellular green algae, most commonly from the genus Chlorella. We reconstructed the phylogeny of cultured algal endosymbionts isolated and maintained in laboratory conditions for years from green Hydra strains collected from four different geographical sites within Croatia, one from Germany and one from Israel. Nuclear (18S rDNA, ITS region) and chloroplast markers (16S, rbcL) for maximum likelihood phylogenetic analyses were used. We focused on investigating the positions of these algal endosymbiotic strains within the chlorophyte lineage. Molecular analyses established that different genera and species of unicellular green algae are present as endosymbionts in green Hydra, showing that endosymbiotic algae growing within green Hydra sampled from four Croatian localities are not monophyletic. Our results indicate that the intracellular algal endosymbionts of green Hydra have become established several times independently in evolution. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Insect Sex Determination Manipulated by Their Endosymbionts: Incidences, Mechanisms and Implications

    Science.gov (United States)

    Kageyama, Daisuke; Narita, Satoko; Watanabe, Masaya

    2012-01-01

    The sex-determining systems of arthropods are surprisingly diverse. Some species have male or female heterogametic sex chromosomes while other species do not have sex chromosomes. Most species are diploids but some species, including wasps, ants, thrips and mites, are haplodiploids (n in males; 2n in females). Many of the sexual aberrations, such as sexual mosaics, sex-specific lethality and conversion of sexuality, can be explained by developmental defects including double fertilization of a binucleate egg, loss of a sex chromosome or perturbation of sex-determining gene expression, which occur accidentally or are induced by certain environmental conditions. However, recent studies have revealed that such sexual aberrations can be caused by various groups of vertically-transmitted endosymbiotic microbes such as bacteria of the genera Wolbachia, Rickettsia, Arsenophonus, Spiroplasma and Cardinium, as well as microsporidian protists. In this review, we first summarize the accumulated data on endosymbiont-induced sexual aberrations, and then discuss how such endosymbionts affect the developmental system of their hosts and what kinds of ecological and evolutionary effects these endosymbionts have on their host populations. PMID:26467955

  11. 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...

  12. 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.

  13. 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.

  14. Assessment of bacterial endosymbiont diversity in Otiorhynchus spp. (Coleoptera: Curculionidae larvae using a multitag 454 pyrosequencing approach

    Directory of Open Access Journals (Sweden)

    Hirsch Jacqueline

    2012-01-01

    Full Text Available Abstract Background Weevils of the genus Otiorhynchus are regarded as devastating pests in a wide variety of horticultural crops worldwide. So far, little is known on the presence of endosymbionts in Otiorhynchus spp.. Investigation of endosymbiosis in this genus may help to understand the evolution of different reproductive strategies in these weevils (parthenogenesis or sexual reproduction, host-symbiont interactions, and may provide a future basis for novel pest management strategy development. Here, we used a multitag 454 pyrosequencing approach to assess the bacterial endosymbiont diversity in larvae of four economically important Otiorhynchus species. Results High-throughput tag-encoded FLX amplicon pyrosequencing of a bacterial 16S rDNA fragment was used to characterise bacterial communities associated with different Otiorhynchus spp. larvae. By sequencing a total of ~48,000 PCR amplicons, we identified 49 different operational taxonomic units (OTUs as bacterial endosymbionts in the four studied Otiorhynchus species. More than 90% of all sequence reads belonged either to the genus Rickettsia or showed homology to the phylogenetic group of “Candidatus Blochmannia” and to endosymbionts of the lice Pedicinus obtusus and P. badii. By using specific primers for the genera Rickettsia and “Candidatus Blochmannia”, we identified a new phylogenetic clade of Rickettsia as well as “Candidatus Nardonella” endosymbionts in Otiorhynchus spp. which are closely related to “Candidatus Blochmannia” bacteria. Conclusions Here, we used multitag 454 pyrosequencing for assessment of insect endosymbiotic communities in weevils. As 454 pyrosequencing generates only quite short sequences, results of such studies can be regarded as a first step towards identifying respective endosymbiotic species in insects. In the second step of our study, we analysed sequences of specific gene regions for a more detailed phylogeny of selected endosymbiont genera

  15. An IMD-like pathway mediates both endosymbiont control and host immunity in the cereal weevil Sitophilus spp.

    Science.gov (United States)

    Maire, Justin; Vincent-Monégat, Carole; Masson, Florent; Zaidman-Rémy, Anna; Heddi, Abdelaziz

    2018-01-08

    Many insects developing on nutritionally unbalanced diets have evolved symbiotic associations with vertically transmitted intracellular bacteria (endosymbionts) that provide them with metabolic components, thereby improving the host's abilities to thrive on such poor ecological niches. While host-endosymbiont coevolutionary constraints are known to entail massive genomic changes in the microbial partner, host's genomic evolution remains elusive, particularly with regard to the immune system. In the cereal weevil Sitophilus spp., which houses Sodalis pierantonius, endosymbionts are secluded in specialized host cells, the bacteriocytes that group together as an organ, the bacteriome. We previously reported that at standard conditions, the bacteriome highly expresses the coleoptericin A (colA) antimicrobial peptide (AMP), which was shown to prevent endosymbiont escape from the bacteriocytes. However, following the insect systemic infection by pathogens, the bacteriome upregulates a cocktail of AMP encoding genes, including colA. The regulations that allow these contrasted immune responses remain unknown. In this short report, we provide evidence that an IMD-like pathway is conserved in two sibling species of cereal weevils, Sitophilus oryzae and Sitophilus zeamais. RNA interference (RNAi) experiments showed that imd and relish genes are essential for (i) colA expression in the bacteriome under standard conditions, (ii) AMP up-regulation in the bacteriome following a systemic immune challenge, and (iii) AMP systemic induction following an immune challenge. Histological analyses also showed that relish inhibition by RNAi resulted in endosymbiont escape from the bacteriome, strengthening the involvement of an IMD-like pathway in endosymbiont control. We conclude that Sitophilus' IMD-like pathway mediates both the bacteriome immune program involved in endosymbiont seclusion within the bacteriocytes and the systemic and local immune responses to exogenous challenges. This

  16. 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 ...

  17. 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 ...

  18. 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 ...

  19. 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

  20. 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,

  1. 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.

  2. 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 ...

  3. 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 ...

  4. 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.

  5. 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 ...

  6. 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

  7. 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 ...

  8. 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.

  9. 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.

  10. 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.

  11. Sinorhizobium meliloti putA gene regulation: a new model within the family Rhizobiaceae.

    Science.gov (United States)

    Soto, M J; Jiménez-Zurdo, J I; van Dillewijn, P; Toro, N

    2000-04-01

    Proline dehydrogenase (PutA) is a bifunctional enzyme that catalyzes the oxidation of proline to glutamate. In Sinorhizobium meliloti, as in other microorganisms, the putA gene is transcriptionally activated in response to proline. In Rhodobacter capsulatus, Agrobacterium, and most probably in Bradyrhizobium, this activation is dependent on an Lrp-like protein encoded by the putR gene, located immediately upstream of putA. Interestingly, sequence and genetic analysis of the region upstream of the S. meliloti putA gene did not reveal such a putR locus or any other encoded transcriptional activator of putA. Furthermore, results obtained with an S. meliloti putA null mutation indicate the absence of any proline-responsive transcriptional activator and that PutA serves as an autogenous repressor. Therefore, the model of S. meliloti putA regulation completely diverges from that of its Rhizobiaceae relatives and resembles more that of enteric bacteria. However, some differences have been found with the latter model: (i) S. meliloti putA gene is not catabolite repressed, and (ii) the gene encoding for the major proline permease (putP) does not form part of an operon with the putA gene.

  12. Inability To Catabolize Galactose Leads to Increased Ability To Compete for Nodule Occupancy in Sinorhizobium meliloti

    Science.gov (United States)

    Geddes, Barney A.

    2012-01-01

    A mutant unable to utilize galactose was isolated in Sinorhizobium meliloti strain Rm1021. The mutation was found to be in a gene annotated dgoK1, a putative 2-keto-3-deoxygalactonokinase. The genetic region was isolated on a complementing cosmid and subsequently characterized. Based on genetic and bioinformatic evidence, the locus encodes all five enzymes (galD, dgoK, dgoA, SMc00883, and ilvD1) involved in the De Ley-Doudoroff pathway for galactose catabolism. Although all five genes are present, genetic analysis suggests that the galactonase (SMc00883) and the dehydratase (ilvD1) are dispensable with respect to the ability to catabolize galactose. In addition, we show that the transport of galactose is partially facilitated by the arabinose transporter (AraABC) and that both glucose and galactose compete with arabinose for transport. Quantitative reverse transcription-PCR (qRT-PCR) data show that in a dgoK background, the galactose locus is constitutively expressed, and the induction of the ara locus seems to be enhanced. Assays of competition for nodule occupancy show that the inability to catabolize galactose is correlated with an increased ability to compete for nodule occupancy. PMID:22797764

  13. Crystallization and preliminary crystallographic studies of the recombinant dihydropyrimidinase from Sinorhizobium meliloti CECT4114

    International Nuclear Information System (INIS)

    Martínez-Rodríguez, Sergio; González-Ramírez, Luis Antonio; Clemente-Jiménez, Josefa María; Rodríguez-Vico, Felipe; Las Heras-Vázquez, Francisco Javier; Gavira, Jose A.; García-Ruíz, Juan Manuel

    2006-01-01

    The dihydropyrimidinase from S. meliloti CECT4114, with activity towards both hydantoin and dihydrouracil substrates, was crystallized, and diffraction data were collected to 1.85 Å resolution. Dihydropyrimidinases are involved in the reductive pathway of pyrimidine degradation, catalysing the hydrolysis of 5,6-dihydrouracil and 5,6-dihydrothymine to the corresponding N-carbamoyl β-amino acids. This enzyme has often been referred to as hydantoinase owing to its industrial application in the production of optically pure amino acids starting from racemic mixtures of 5-monosubstituted hydantoins. Recombinant dihydropyrimidinase from Sinorhizobium meliloti CECT4114 (SmelDhp) has been expressed, purified and crystallized. Crystallization was performed using the counter-diffusion method with capillaries of 0.3 mm inner diameter. Crystals of SmelDhp suitable for data collection and structure determination were grown in the presence of agarose at 0.1%(w/v) in order to ensure mass transport controlled by diffusion. X-ray data were collected to a resolution of 1.85 Å. The crystal belongs to the orthorhombic space group C222 1 , with unit-cell parameters a = 124.89, b = 126.28, c = 196.10 Å and two molecules in the asymmetric unit. A molecular-replacement solution has been determined and refinement is in progress

  14. Comprehensive metabolite profiling of Sinorhizobium meliloti using gas chromatography-mass spectrometry.

    Science.gov (United States)

    Barsch, Aiko; Patschkowski, Thomas; Niehaus, Karsten

    2004-10-01

    A metabolite analysis of the soil bacterium Sinorhizobium meliloti was established as a first step towards a better understanding of the symbiosis with its host plant Medicago truncatula. A crucial step was the development of fast harvesting and extraction methods for the bacterial metabolites because of rapid changes in their composition. S. meliloti 1021 cell cultures grown in minimal medium were harvested by centrifugation, filtration or immediate freezing in liquid nitrogen followed by a lyophilisation step. Bacteria were lysed mechanically in methanol and hydrophilic compounds were analysed after methoxymation and silylisation via GC-MS. The different compounds were identified by comparison with the NIST 98 database and available standards. From about 200 peaks in each chromatogram 65 compounds have been identified so far. A comparison of the different extraction methods giving the metabolite composition revealed clear changes in several amino acids and amino acid precursor pools. A principal component analysis (PCA) was able to distinguish S. meliloti cells grown on different carbon sources based on their metabolite profile. A comparison of the metabolite composition of a S. meliloti leucine auxotrophic mutant with the wild type revealed a marked accumulation of 2-isopropylmalate in the mutant. Interestingly, the accumulated metabolite is not the direct substrate of the mutated enzyme, 3-isopropylmalate dehydrogenase, but the substrate of isopropylmalate isomerase, which acts one step further upstream in the biosynthetic pathway of leucine. This finding further emphasises the importance of integrating metabolic data into post-genomic research.

  15. Mutualistic co-evolution of type III effector genes in Sinorhizobium fredii and Bradyrhizobium japonicum.

    Directory of Open Access Journals (Sweden)

    Jeffrey A Kimbrel

    2013-02-01

    Full Text Available Two diametric paradigms have been proposed to model the molecular co-evolution of microbial mutualists and their eukaryotic hosts. In one, mutualist and host exhibit an antagonistic arms race and each partner evolves rapidly to maximize their own fitness from the interaction at potential expense of the other. In the opposing model, conflicts between mutualist and host are largely resolved and the interaction is characterized by evolutionary stasis. We tested these opposing frameworks in two lineages of mutualistic rhizobia, Sinorhizobium fredii and Bradyrhizobium japonicum. To examine genes demonstrably important for host-interactions we coupled the mining of genome sequences to a comprehensive functional screen for type III effector genes, which are necessary for many Gram-negative pathogens to infect their hosts. We demonstrate that the rhizobial type III effector genes exhibit a surprisingly high degree of conservation in content and sequence that is in contrast to those of a well characterized plant pathogenic species. This type III effector gene conservation is particularly striking in the context of the relatively high genome-wide diversity of rhizobia. The evolution of rhizobial type III effectors is inconsistent with the molecular arms race paradigm. Instead, our results reveal that these loci are relatively static in rhizobial lineages and suggest that fitness conflicts between rhizobia mutualists and their host plants have been largely resolved.

  16. [Factor analysis of interactions between alfalfa nodule bacteria (Sinorhizobium meliloti) genes that regulate symbiotic nitrogen fixation].

    Science.gov (United States)

    Provorov, N A; Chuklina, E; Vorob'ev, N I; Onishchuk, O P; Simarov, B V

    2013-04-01

    Factor analysis has been conducted for the data on the interaction between the genes of the root nodule bacteria (rhizobia), which influence the efficiency of symbiosis with leguminous plants, including dctA (encoding succinate permease), dctBD (activating the dctA gene due to binding its enhancer in the presence of succinate), rpoN (activating the promoters of dctA and nitrogenase genes nifHDK), and nifA (activating the nitrogenase genes due to binding their enhancers). The analysis of the alfalfa rhizobia (Sinorhizobium meliloti) recombinants that contain additional copies ofthese genes suggested the antagonistic (epistatic) interaction between nifA and rpoN. It may be associated either with the competition for C compounds imported into the nodules between the energy production and nitrogen assimilation processes or with the competition for redox potentials between the oxidative phosphorylation and nitrogen fixation processes. Since the phenotypic effects of the studied genes depend on the activity of nitrogen export into the aerial parts of plants, we suppose that its accumulation in bacteroids impairs the activation of the nifHDK genes by the NifA protein due to its interaction with the GlnB protein (the nitrogen metabolism regulator) or with the FixLJ and ActSR proteins (the redox potential regulators).

  17. Site-Specific Ser/Thr/Tyr Phosphoproteome of Sinorhizobium meliloti at Stationary Phase.

    Directory of Open Access Journals (Sweden)

    Tao Liu

    Full Text Available Sinorhizobium meliloti, a facultative microsymbiont of alfalfa, should fine-tune its cellular processes to live saprophytically in soils characterized with limited nutrients and diverse stresses. In this study, TiO2 enrichment and LC-MS/MS were used to uncover the site-specific Ser/Thr/Tyr phosphoproteome of S. meliloti in minimum medium at stationary phase. There are a total of 96 unique phosphorylated sites, with a Ser/Thr/Tyr distribution of 63:28:5, in 77 proteins. Phosphoproteins identified in S. meliloti showed a wide distribution pattern regarding to functional categories, such as replication, transcription, translation, posttranslational modification, transport and metabolism of amino acids, carbohydrate, inorganic ion, succinoglycan etc. Ser/Thr/Tyr phosphosites identified within the conserved motif in proteins of key cellular function indicate a crucial role of phosphorylation in modulating cellular physiology. Moreover, phosphorylation in proteins involved in processes related to rhizobial adaptation was also discussed, such as those identified in SMa0114 and PhaP2 (polyhydroxybutyrate synthesis, ActR (pH stress and microaerobic adaption, SupA (potassium stress, chaperonin GroEL2 (viability and potentially symbiosis, and ExoP (succinoglycan synthesis and secretion. These Ser/Thr/Tyr phosphosites identified herein would be helpful for our further investigation and understanding of the role of phosphorylation in rhizobial physiology.

  18. Role of extracellular compounds in Cd-sequestration relative to Cd uptake by bacterium Sinorhizobium meliloti

    Energy Technology Data Exchange (ETDEWEB)

    Slaveykova, Vera I., E-mail: vera.slaveykova@epfl.c [Environmental Biophysical Chemistry, IIE-ENAC, Ecole Polytechnique Federale de Lausanne (EPFL), Station 2, CH-1015 Lausanne (Switzerland); Parthasarathy, Nalini [Department of Inorganic, Analytic and Applied Chemistry, University of Geneva, Sciences II, 30 Quai Ernest Ansermet, 1211 Geneva 4 (Switzerland); Dedieu, Karine; Toescher, Denis [Environmental Biophysical Chemistry, IIE-ENAC, Ecole Polytechnique Federale de Lausanne (EPFL), Station 2, CH-1015 Lausanne (Switzerland)

    2010-08-15

    The role of bacterially derived compounds in Cd(II) complexation and uptake by bacterium Sinorhizobium meliloti wild type (WT) and genetically modified ExoY-mutant, deficient in exopolysaccharide production, was explored combining chemical speciation measurements and assays with living bacteria. Obtained results demonstrated that WT- and ExoY-strains excreted siderophores in comparable amounts, while WT-strain produced much higher amount of exopolysaccharides and less exoproteins. An evaluation of Cd(II) distribution in bacterial suspensions under short term exposure conditions, showed that most of the Cd is bound to bacterial surface envelope, including Cd bound to the cell wall and to the attached extracellular polymeric substances. However, the amount of Cd bound to the dissolved extracellular compounds increases at high Cd(II) concentrations. The implications of these findings to more general understanding of the Cd(II) fate and cycling in the environment is discussed. - Bacterial excreted extracellular compounds play minor role in Cd(II) sequestration relative to bacteria.

  19. Crystallization and preliminary crystallographic studies of the recombinant dihydropyrimidinase from Sinorhizobium meliloti CECT4114

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Rodríguez, Sergio [Departamento de Química Física, Bioquímica y Química Inorgánica, Área de Bioquímica y Biología Molecular, Edificio CITE I, Universidad de Almería (Spain); González-Ramírez, Luis Antonio [Laboratorio de Estudios Cristalográficos-IACT, CSIC-UGRA, P. T. Ciencias de la Salud, Granada 18100 (Spain); Clemente-Jiménez, Josefa María; Rodríguez-Vico, Felipe; Las Heras-Vázquez, Francisco Javier [Departamento de Química Física, Bioquímica y Química Inorgánica, Área de Bioquímica y Biología Molecular, Edificio CITE I, Universidad de Almería (Spain); Gavira, Jose A.; García-Ruíz, Juan Manuel, E-mail: jmgruiz@ugr.es [Laboratorio de Estudios Cristalográficos-IACT, CSIC-UGRA, P. T. Ciencias de la Salud, Granada 18100 (Spain); Departamento de Química Física, Bioquímica y Química Inorgánica, Área de Bioquímica y Biología Molecular, Edificio CITE I, Universidad de Almería (Spain)

    2006-12-01

    The dihydropyrimidinase from S. meliloti CECT4114, with activity towards both hydantoin and dihydrouracil substrates, was crystallized, and diffraction data were collected to 1.85 Å resolution. Dihydropyrimidinases are involved in the reductive pathway of pyrimidine degradation, catalysing the hydrolysis of 5,6-dihydrouracil and 5,6-dihydrothymine to the corresponding N-carbamoyl β-amino acids. This enzyme has often been referred to as hydantoinase owing to its industrial application in the production of optically pure amino acids starting from racemic mixtures of 5-monosubstituted hydantoins. Recombinant dihydropyrimidinase from Sinorhizobium meliloti CECT4114 (SmelDhp) has been expressed, purified and crystallized. Crystallization was performed using the counter-diffusion method with capillaries of 0.3 mm inner diameter. Crystals of SmelDhp suitable for data collection and structure determination were grown in the presence of agarose at 0.1%(w/v) in order to ensure mass transport controlled by diffusion. X-ray data were collected to a resolution of 1.85 Å. The crystal belongs to the orthorhombic space group C222{sub 1}, with unit-cell parameters a = 124.89, b = 126.28, c = 196.10 Å and two molecules in the asymmetric unit. A molecular-replacement solution has been determined and refinement is in progress.

  20. Presence of Wolbachia endosymbionts in microfilariae of Wuchereria bancrofti (Spirurida: Onchocercidae from different geographical regions in India

    Directory of Open Access Journals (Sweden)

    Hoti SL

    2003-01-01

    Full Text Available In view of the recent discovery of rickettsial endosymbionts, Wolbachia in lymphatic filarial parasites, Wuchereria bancrofti and Brugia malayi and subsequently of their vital role in the survival and development of the latter, antibiotics such as tetracycline are being suggested for the treatment of lymphatic filariasis, by way of eliminating the endosymbiont. But, it is essential to assess their presence in parasites from areas endemic for lymphatic filariasis before such a new control tool is employed. In the present communication, we report the detection of Wolbachia endosymbionts in microfilariae of W. bancrofti parasites collected from geographically distant locations of India, such as Pondicherry (Union Territory, Calicut (Kerala, Jagadalpur (Madhya Pradesh, Thirukoilur (TamilNadu, Chinnanergunam (TamilNadu, Rajahmundry (Andhra Pradesh, and Varanasi (Uttar Pradesh, using Wolbachia specific 16S rDNA polymerase chain reaction.

  1. 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.

  2. 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.

  3. 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.

  4. Testing the reproducibility of multiple displacement amplification on genomes of clonal endosymbiont populations.

    Directory of Open Access Journals (Sweden)

    Kirsten Maren Ellegaard

    Full Text Available The multiple displacement amplification method has revolutionized genomic studies of uncultured bacteria, where the extraction of pure DNA in sufficient quantity for next-generation sequencing is challenging. However, the method is problematic in that it amplifies the target DNA unevenly, induces the formation of chimeric reads and also amplifies contaminating DNA. Here, we have tested the reproducibility of the multiple displacement amplification method using serial dilutions of extracted genomic DNA and intact cells from the cultured endosymbiont Bartonella australis. The amplified DNA was sequenced with the Illumina sequencing technology, and the results were compared to sequence data obtained from unamplified DNA in this study as well as from a previously published genome project. We show that artifacts such as the extent of the amplification bias, the percentage of chimeric reads and the relative fraction of contaminating DNA increase dramatically for the smallest amounts of template DNA. The pattern of read coverage was reproducibly obtained for samples with higher amounts of template DNA, suggesting that the bias is non-random and genome-specific. A re-analysis of previously published sequence data obtained after amplification from clonal endosymbiont populations confirmed these predictions. We conclude that many of the artifacts associated with the use of the multiple displacement amplification method can be alleviated or much reduced by using multiple cells as the template for the amplification. These findings should be particularly useful for researchers studying the genomes of endosymbionts and other uncultured bacteria, for which a small clonal population of cells can be isolated.

  5. Multiple Acquisitions of Pathogen-Derived Francisella Endosymbionts in Soft Ticks.

    Science.gov (United States)

    Gerhart, Jonathan G; Auguste Dutcher, H; Brenner, Amanda E; Moses, Abraham S; Grubhoffer, Libor; Raghavan, Rahul

    2018-02-01

    Bacterial endosymbionts of ticks are of interest due to their close evolutionary relationships with tick-vectored pathogens. For instance, whereas many ticks contain Francisella-like endosymbionts (FLEs), others transmit the mammalian pathogen Francisella tularensis. We recently sequenced the genome of an FLE present in the hard tick Amblyomma maculatum (FLE-Am) and showed that it likely evolved from a pathogenic ancestor. In order to expand our understanding of FLEs, in the current study we sequenced the genome of an FLE in the soft tick Ornithodoros moubata and compared it to the genomes of FLE-Am, Francisella persica-an FLE in the soft tick Argus (Persicargas) arboreus, Francisella sp. MA067296-a clinical isolate responsible for an opportunistic human infection, and F. tularensis, the established human pathogen. We determined that FLEs and MA067296 belonged to a sister taxon of mammalian pathogens, and contained inactivated versions of virulence genes present in F. tularensis, indicating that the most recent common ancestor shared by FLEs and F. tularensis was a potential mammalian pathogen. Our analyses also revealed that the two soft ticks (O. moubata and A. arboreus) probably acquired their FLEs separately, suggesting that the virulence attenuation observed in FLEs are not the consequence of a single acquisition event followed by speciation, but probably due to independent transitions of pathogenic francisellae into nonpathogenic FLEs within separate tick lineages. Additionally, we show that FLEs encode intact pathways for the production of several B vitamins and cofactors, denoting that they could function as nutrient-provisioning endosymbionts in ticks. © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  6. 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

  7. 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 ...

  8. 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 ...

  9. [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.

  10. 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...

  11. 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.

  12. 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 ...

  13. 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.

  14. The evolutionary development of plant-feeding insects and their nutritional endosymbionts.

    Science.gov (United States)

    Skidmore, Isabel H; Hansen, Allison K

    2017-12-01

    Herbivorous insects have evolved diverse mechanisms enabling them to feed on plants with suboptimal nutrient availability. Low nutrient availability negatively impacts insect herbivore development and fitness. To overcome this obstacle numerous insect lineages have evolved intimate associations with nutritional endosymbionts. This is especially true for insects that specialize on nitrogen-poor substrates, as these insects are highly dependent on intracellular symbionts to provide nitrogen lacking in their insect host's diet. Emerging evidence in these systems suggest that the symbiont's and/or the insect's biosynthetic pathways are dynamically regulated throughout the insect's development to potentially cope with the insect's changing nutritional demands. In this review, we evaluate the evolutionary development of symbiotic insect cells (bacteriocytes) by comparing and contrasting genes and mechanisms involved in maintaining and regulating the nutritional symbiosis throughout insect development in a diversity of insect herbivore-endosymbiont associations. With new advances in genome sequencing and functional genomics, we evaluate to what extent nutritional symbioses are shaped by (i) the regulation of symbiont titer, (ii) the regulation of insect symbiosis genes, and (iii) the regulation of symbiont genes. We discuss how important these mechanisms are for the biosynthesis of essential amino acids and vitamins across insect life stages in divergent insect-symbiont systems. We conclude by suggesting future directions of research to further elucidate the evolutionary development of bacteriocytes and the impact of these nutritional symbioses on insect-plant interactions. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  15. Genetic manipulation of endosymbionts to control vector and vector borne diseases

    Directory of Open Access Journals (Sweden)

    Jay Prakash Gupta

    Full Text Available Vector borne diseases (VBD are on the rise because of failure of the existing methods of control of vector and vector borne diseases and the climate change. A steep rise of VBDs are due to several factors like selection of insecticide resistant vector population, drug resistant parasite population and lack of effective vaccines against the VBDs. Environmental pollution, public health hazard and insecticide resistant vector population indicate that the insecticides are no longer a sustainable control method of vector and vector-borne diseases. Amongst the various alternative control strategies, symbiont based approach utilizing endosymbionts of arthropod vectors could be explored to control the vector and vector borne diseases. The endosymbiont population of arthropod vectors could be exploited in different ways viz., as a chemotherapeutic target, vaccine target for the control of vectors. Expression of molecules with antiparasitic activity by genetically transformed symbiotic bacteria of disease-transmitting arthropods may serve as a powerful approach to control certain arthropod-borne diseases. Genetic transformation of symbiotic bacteria of the arthropod vector to alter the vector’s ability to transmit pathogen is an alternative means of blocking the transmission of VBDs. In Indian scenario, where dengue, chikungunya, malaria and filariosis are prevalent, paratransgenic based approach can be used effectively. [Vet World 2012; 5(9.000: 571-576

  16. Endosymbiont gene functions impaired and rescued by polymerase infidelity at poly(A) tracts

    Science.gov (United States)

    Tamas, Ivica; Wernegreen, Jennifer J.; Nystedt, Björn; Kauppinen, Seth N.; Darby, Alistair C.; Gomez-Valero, Laura; Lundin, Daniel; Poole, Anthony M.; Andersson, Siv G. E.

    2008-01-01

    Among host-dependent bacteria that have evolved by extreme reductive genome evolution, long-term bacterial endosymbionts of insects have the smallest (160–790 kb) and most A + T-rich (>70%) bacterial genomes known to date. These genomes are riddled with poly(A) tracts, and 5–50% of genes contain tracts of 10 As or more. Here, we demonstrate transcriptional slippage at poly(A) tracts within genes of Buchnera aphidicola associated with aphids and Blochmannia pennsylvanicus associated with ants. Several tracts contain single frameshift deletions; these apparent pseudogenes showed patterns of constraint consistent with purifying selection on the encoded proteins. Transcriptional slippage yielded a heterogeneous population of transcripts with variable numbers of As in the tract. Across several frameshifted genes, including B. aphidicola cell wall biosynthesis genes and a B. pennsylvanicus histidine biosynthesis gene, 12–50% of transcripts contained corrected reading frames that could potentially yield full-length proteins. In situ immunostaining confirmed the production of the cell wall biosynthetic enzyme UDP-N-acetylmuramyl pentapeptide synthase encoded by the frameshifted murF gene. Simulation studies indicated an overrepresentation of poly(A) tracts in endosymbiont genomes relative to other A + T-rich bacterial genomes. Polymerase infidelity at poly(A) tracts rescues the functionality of genes with frameshift mutations and, conversely, reduces the efficiency of expression for in-frame genes carrying poly(A) regions. These features of homopolymeric tracts could be exploited to manipulate gene expression in small synthetic genomes. PMID:18815381

  17. Systematics of a kleptoplastidal dinoflagellate, Gymnodinium eucyaneum Hu (Dinophyceae), and its cryptomonad endosymbiont.

    Science.gov (United States)

    Xia, Shuang; Zhang, Qi; Zhu, Huan; Cheng, Yingyin; Liu, Guoxiang; Hu, Zhengyu

    2013-01-01

    New specimens of the kleptoplastidal dinoflagellate Gymnodinium eucyaneum Hu were collected in China. We investigated the systematics of the dinoflagellate and the origin of its endosymbiont based on light morphology and phylogenetic analyses using multiple DNA sequences. Cells were dorsoventrally flattened with a sharply acute hypocone and a hemispherical epicone. The confusion between G. eucyaneum and G. acidotum Nygaard still needs to be resolved. We found that the hypocone was conspicuously larger than the epicone in most G. eucyaneum cells, which differed from G. acidotum, but there were a few cells whose hypocone and epicone were of nearly the same size. In addition, there was only one site difference in the partial nuclear LSU rDNA sequences of a sample from Japan given the name G. acidotum and G. eucyaneum in the present study, which suggest that G. eucyaneum may be a synonym of G. acidotum. Spectroscopic analyses and phylogenetic analyses based on nucleomorph SSU rDNA sequences and chloroplast 23 s rDNA sequences suggested that the endosymbiont of G. eucyaneum was derived from Chroomonas (Cryptophyta), and that it was most closely related to C. coerulea Skuja. Moreover, the newly reported kleptoplastidal dinoflagellates G. myriopyrenoides and G. eucyaneum in our study were very similar, and the taxonomy of kleptoplastidal dinoflagellates was discussed.

  18. Systematics of a kleptoplastidal dinoflagellate, Gymnodinium eucyaneum Hu (Dinophyceae, and its cryptomonad endosymbiont.

    Directory of Open Access Journals (Sweden)

    Shuang Xia

    Full Text Available New specimens of the kleptoplastidal dinoflagellate Gymnodinium eucyaneum Hu were collected in China. We investigated the systematics of the dinoflagellate and the origin of its endosymbiont based on light morphology and phylogenetic analyses using multiple DNA sequences. Cells were dorsoventrally flattened with a sharply acute hypocone and a hemispherical epicone. The confusion between G. eucyaneum and G. acidotum Nygaard still needs to be resolved. We found that the hypocone was conspicuously larger than the epicone in most G. eucyaneum cells, which differed from G. acidotum, but there were a few cells whose hypocone and epicone were of nearly the same size. In addition, there was only one site difference in the partial nuclear LSU rDNA sequences of a sample from Japan given the name G. acidotum and G. eucyaneum in the present study, which suggest that G. eucyaneum may be a synonym of G. acidotum. Spectroscopic analyses and phylogenetic analyses based on nucleomorph SSU rDNA sequences and chloroplast 23 s rDNA sequences suggested that the endosymbiont of G. eucyaneum was derived from Chroomonas (Cryptophyta, and that it was most closely related to C. coerulea Skuja. Moreover, the newly reported kleptoplastidal dinoflagellates G. myriopyrenoides and G. eucyaneum in our study were very similar, and the taxonomy of kleptoplastidal dinoflagellates was discussed.

  19. First report of endosymbionts in Dreissena polymorpha from the brackish Curonian Lagoon, SE Baltic Sea

    Directory of Open Access Journals (Sweden)

    Romualda Chuševė

    2012-11-01

    Full Text Available We report the first results of a parasitological study ofDreissena polymorpha (zebra mussels from the brackishCuronian Lagoon, SE Baltic Sea. Zebra mussels were collected monthlyfrom May to October 2011 from a site near the mouth of the River Nemunas.Three types of endosymbionts were found in the mantle cavity andvisceral mass of the molluscs during dissections, i.e. thecommensal ciliate Conchophthirus acuminatus and parasitic ciliateOphryoglena sp., and rarely encountered, unidentified nematodes.The abundances of C. cuminatus and Ophryoglena sp.were positively associated with host shell length and watertemperature, but no effect of water salinity was detected.As the endosymbionts are either highly host-specific to zebra mussels(C. acuminatus and Ophryoglena sp. or are probablyfree-living organisms that inadvertently infect the molluscs (nematodes,we conclude that the presence of D. polymorpha in theCuronian Lagoon does not pose any serious parasitologicalrisk to native biota. We emphasize, however, that this conclusionshould be treated with caution as it is based on a study conductedonly at a single location. Our work extends the currentlyscarce records of D. polymorpha parasites and commensals frombrackish waters, and adds to a better understanding of the ecologicalimpact this highly invasive mollusc causes in the areas it has invaded.

  20. 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...

  1. 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.

  2. 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.

  3. Mining the Sinorhizobium meliloti transportome to develop FRET biosensors for sugars, dicarboxylates and cyclic polyols.

    Directory of Open Access Journals (Sweden)

    Alexandre Bourdès

    Full Text Available Förster resonance energy transfer (FRET biosensors are powerful tools to detect biologically important ligands in real time. Currently FRET bisosensors are available for twenty-two compounds distributed in eight classes of chemicals (two pentoses, two hexoses, two disaccharides, four amino acids, one nucleobase, two nucleotides, six ions and three phytoestrogens. To expand the number of available FRET biosensors we used the induction profile of the Sinorhizobium meliloti transportome to systematically screen for new FRET biosensors.Two new vectors were developed for cloning genes for solute-binding proteins (SBPs between those encoding FRET partner fluorescent proteins. In addition to a vector with the widely used cyan and yellow fluorescent protein FRET partners, we developed a vector using orange (mOrange2 and red fluorescent protein (mKate2 FRET partners. From the sixty-nine SBPs tested, seven gave a detectable FRET signal change on binding substrate, resulting in biosensors for D-quinic acid, myo-inositol, L-rhamnose, L-fucose, β-diglucosides (cellobiose and gentiobiose, D-galactose and C4-dicarboxylates (malate, succinate, oxaloacetate and fumarate. To our knowledge, we describe the first two FRET biosensor constructs based on SBPs from Tripartite ATP-independent periplasmic (TRAP transport systems.FRET based on orange (mOrange2 and red fluorescent protein (mKate2 partners allows the use of longer wavelength light, enabling deeper penetration of samples at lower energy and increased resolution with reduced back-ground auto-fluorescence. The FRET biosensors described in this paper for four new classes of compounds; (i cyclic polyols, (ii L-deoxy sugars, (iii β-linked disaccharides and (iv C4-dicarboxylates could be developed to study metabolism in vivo.

  4. Exploring the symbiotic pangenome of the nitrogen-fixing bacterium Sinorhizobium meliloti

    Energy Technology Data Exchange (ETDEWEB)

    Galardini, Marco [University of Florence; Mengoni, Alessio [University of Florence; Brilli, Matteo [Universite de Lyon, France; Pini, Francesco [University of Florence; Fioravanti, Antonella [University of Florence; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Daligault, Hajnalka E. [Los Alamos National Laboratory (LANL); Bruce, David [Los Alamos National Laboratory (LANL); Detter, J. Chris [U.S. Department of Energy, Joint Genome Institute; Tapia, Roxanne [Los Alamos National Laboratory (LANL); Han, Cliff [Los Alamos National Laboratory (LANL); Teshima, Hazuki [Los Alamos National Laboratory (LANL); Mocali, Stefano [Agrobiol & Pedol Ctr ABP, Agr Res Council, I-50121 Florence, Italy; Bazzicalupo, Marco [University of Florence; Biondi, Emanuele [University of Florence

    2011-01-01

    Background: Sinorhizobium meliloti is a model system for the studies of symbiotic nitrogen fixation. An extensive polymorphism at the genetic and phenotypic level is present in natural populations of this species, especially in relation with symbiotic promotion of plant growth. AK83 and BL225C are two nodule-isolated strains with diverse symbiotic phenotypes; BL225C is more efficient in promoting growth of the Medicago sativa plants than strain AK83. In order to investigate the genetic determinants of the phenotypic diversification of S. meliloti strains AK83 and BL225C, we sequenced the complete genomes for these two strains. Results: With sizes of 7.14 Mbp and 6.97 Mbp, respectively, the genomes of AK83 and BL225C are larger than the laboratory strain Rm1021. The core genome of Rm1021, AK83, BL225C strains included 5124 orthologous groups, while the accessory genome was composed by 2700 orthologous groups. While Rm1021 and BL225C have only three replicons (Chromosome, pSymA and pSymB), AK83 has also two plasmids, 260 and 70 Kbp long. We found 65 interesting orthologous groups of genes that were present only in the accessory genome, consequently responsible for phenotypic diversity and putatively involved in plant-bacterium interaction. Notably, the symbiosis inefficient AK83 lacked several genes required for microaerophilic growth inside nodules, while several genes for accessory functions related to competition, plant invasion and bacteroid tropism were identified only in AK83 and BL225C strains. Presence and extent of polymorphism in regulons of transcription factors involved in symbiotic interaction were also analyzed. Our results indicate that regulons are flexible, with a large number of accessory genes, suggesting that regulons polymorphism could also be a key determinant in the variability of symbiotic performances among the analyzed strains.

  5. Interaction between Nitrogen and Phosphate Stress Responses inSinorhizobium meliloti.

    Science.gov (United States)

    Hagberg, Kelly L; Yurgel, Svetlana N; Mulder, Monika; Kahn, Michael L

    2016-01-01

    Bacteria have developed various stress response pathways to improve their assimilation and allocation of limited nutrients, such as nitrogen and phosphate. While both the nitrogen stress response (NSR) and phosphate stress response (PSR) have been studied individually, there are few experiments reported that characterize effects of multiple stresses on one or more pathways in Sinorhizobium meliloti , a facultatively symbiotic, nitrogen-fixing bacteria. The P II proteins, GlnB and GlnK, regulate the NSR activity, but analysis of global transcription changes in a P II deficient mutant suggest that the S. meliloti P II proteins may also regulate the PSR. P II double deletion mutants grow very slowly and pseudoreversion of the slow growth phenotype is common. To understand this phenomenon better, transposon mutants were isolated that had a faster growing phenotype. One mutation was in phoB , the response regulator for a two component regulatory system that is important in the PSR. phoB ::Tn 5 mutants had different phenotypes in the wild type compared to a P II deficient background. This led to the hypothesis that phosphate stress affects the NSR and conversely, that nitrogen stress affects the PSR. Our results show that phosphate availability affects glutamine synthetase activity and expression, which are often used as indicators of NSR activity, but that nitrogen availability did not affect alkaline phosphatase activity and expression, which are indicators of PSR activity. We conclude that the NSR is co-regulated by nitrogen and phosphate, whereas the PSR does not appear to be co-regulated by nitrogen in addition to its known phosphate regulation.

  6. Alfalfa forage digestibility, quality and yield under future climate change scenarios vary with Sinorhizobium meliloti strain.

    Science.gov (United States)

    Sanz-Sáez, Álvaro; Erice, Gorka; Aguirreolea, Jone; Muñoz, Fernando; Sánchez-Díaz, Manuel; Irigoyen, Juan José

    2012-05-15

    Elevated CO(2) may decrease alfalfa forage quality and in vitro digestibility through a drop in crude protein and an enhancement of fibre content. The aim of the present study was to analyse the effect of elevated CO(2), elevated temperature and Sinorhizobium meliloti strains (102F78, 102F34 and 1032 GMI) on alfalfa yield, forage quality and in vitro dry matter digestibility. This objective is in line with the selection of S. meliloti strains in order to maintain high forage yield and quality under future climate conditions. Plants inoculated with the 102F34 strain showed more DM production than those inoculated with 1032GMI; however, these strains did not show significant differences with 102F78 plants. Neutral or acid detergent fibres were not enhanced in plants inoculated with the 102F34 strain under elevated CO(2) or temperature and hence, in vitro dry matter digestibility was unaffected. Crude protein content, an indicator of forage quality, was negatively related to shoot yield. Plants inoculated with 102F78 showed a similar shoot yield to those inoculated with 102F34, but had higher crude protein content at elevated CO(2) and temperature. Under these climate change conditions, 102F78 inoculated plants produced higher quality forage. However, the higher digestibility of plants inoculated with the 102F34 strain under any CO(2) or temperature conditions makes them more suitable for growing under climate change conditions. In general, elevated CO(2) in combination with high temperature (Climate Change scenario) reduced IVDMD and CP content and enhanced fibre content, which means that animal production will be negatively affected. Copyright © 2012 Elsevier GmbH. All rights reserved.

  7. Quantitative Proteomic Analysis of the Hfq-Regulon in Sinorhizobium meliloti 2011

    Science.gov (United States)

    Sobrero, Patricio; Schlüter, Jan-Philip; Lanner, Ulrike; Schlosser, Andreas; Becker, Anke; Valverde, Claudio

    2012-01-01

    Riboregulation stands for RNA-based control of gene expression. In bacteria, small non-coding RNAs (sRNAs) are a major class of riboregulatory elements, most of which act at the post-transcriptional level by base-pairing target mRNA genes. The RNA chaperone Hfq facilitates antisense interactions between target mRNAs and regulatory sRNAs, thus influencing mRNA stability and/or translation rate. In the α-proteobacterium Sinorhizobium meliloti strain 2011, the identification and detection of multiple sRNAs genes and the broadly pleitropic phenotype associated to the absence of a functional Hfq protein both support the existence of riboregulatory circuits controlling gene expression to ensure the fitness of this bacterium in both free living and symbiotic conditions. In order to identify target mRNAs subject to Hfq-dependent riboregulation, we have compared the proteome of an hfq mutant and the wild type S. meliloti by quantitative proteomics following protein labelling with 15N. Among 2139 univocally identified proteins, a total of 195 proteins showed a differential abundance between the Hfq mutant and the wild type strain; 65 proteins accumulated ≥2-fold whereas 130 were downregulated (≤0.5-fold) in the absence of Hfq. This profound proteomic impact implies a major role for Hfq on regulation of diverse physiological processes in S. meliloti, from transport of small molecules to homeostasis of iron and nitrogen. Changes in the cellular levels of proteins involved in transport of nucleotides, peptides and amino acids, and in iron homeostasis, were confirmed with phenotypic assays. These results represent the first quantitative proteomic analysis in S. meliloti. The comparative analysis of the hfq mutant proteome allowed identification of novel strongly Hfq-regulated genes in S. meliloti. PMID:23119037

  8. Malic Enzyme Cofactor and Domain Requirements for Symbiotic N2 Fixation by Sinorhizobium meliloti▿ †

    Science.gov (United States)

    Mitsch, Michael J.; Cowie, Alison; Finan, Turlough M.

    2007-01-01

    The NAD+-dependent malic enzyme (DME) and the NADP+-dependent malic enzyme (TME) of Sinorhizobium meliloti are representatives of a distinct class of malic enzymes that contain a 440-amino-acid N-terminal region homologous to other malic enzymes and a 330-amino-acid C-terminal region with similarity to phosphotransacetylase enzymes (PTA). We have shown previously that dme mutants of S. meliloti fail to fix N2 (Fix−) in alfalfa root nodules, whereas tme mutants are unimpaired in their N2-fixing ability (Fix+). Here we report that the amount of DME protein in bacteroids is 10 times greater than that of TME. We therefore investigated whether increased TME activity in nodules would allow TME to function in place of DME. The tme gene was placed under the control of the dme promoter, and despite elevated levels of TME within bacteroids, no symbiotic nitrogen fixation occurred in dme mutant strains. Conversely, expression of dme from the tme promoter resulted in a large reduction in DME activity and symbiotic N2 fixation. Hence, TME cannot replace the symbiotic requirement for DME. In further experiments we investigated the DME PTA-like domain and showed that it is not required for N2 fixation. Thus, expression of a DME C-terminal deletion derivative or the Escherichia coli NAD+-dependent malic enzyme (sfcA), both of which lack the PTA-like region, restored wild-type N2 fixation to a dme mutant. Our results have defined the symbiotic requirements for malic enzyme and raise the possibility that a constant high ratio of NADPH + H+ to NADP in nitrogen-fixing bacteroids prevents TME from functioning in N2-fixing bacteroids. PMID:17071765

  9. Malic enzyme cofactor and domain requirements for symbiotic N2 fixation by Sinorhizobium meliloti.

    Science.gov (United States)

    Mitsch, Michael J; Cowie, Alison; Finan, Turlough M

    2007-01-01

    The NAD(+)-dependent malic enzyme (DME) and the NADP(+)-dependent malic enzyme (TME) of Sinorhizobium meliloti are representatives of a distinct class of malic enzymes that contain a 440-amino-acid N-terminal region homologous to other malic enzymes and a 330-amino-acid C-terminal region with similarity to phosphotransacetylase enzymes (PTA). We have shown previously that dme mutants of S. meliloti fail to fix N(2) (Fix(-)) in alfalfa root nodules, whereas tme mutants are unimpaired in their N(2)-fixing ability (Fix(+)). Here we report that the amount of DME protein in bacteroids is 10 times greater than that of TME. We therefore investigated whether increased TME activity in nodules would allow TME to function in place of DME. The tme gene was placed under the control of the dme promoter, and despite elevated levels of TME within bacteroids, no symbiotic nitrogen fixation occurred in dme mutant strains. Conversely, expression of dme from the tme promoter resulted in a large reduction in DME activity and symbiotic N(2) fixation. Hence, TME cannot replace the symbiotic requirement for DME. In further experiments we investigated the DME PTA-like domain and showed that it is not required for N(2) fixation. Thus, expression of a DME C-terminal deletion derivative or the Escherichia coli NAD(+)-dependent malic enzyme (sfcA), both of which lack the PTA-like region, restored wild-type N(2) fixation to a dme mutant. Our results have defined the symbiotic requirements for malic enzyme and raise the possibility that a constant high ratio of NADPH + H(+) to NADP in nitrogen-fixing bacteroids prevents TME from functioning in N(2)-fixing bacteroids.

  10. Infection of Bacterial Endosymbionts in Insects: A Comparative Study of Two Techniques viz PCR and FISH for Detection and Localization of Symbionts in Whitefly, Bemisia tabaci.

    Directory of Open Access Journals (Sweden)

    Harpreet Singh Raina

    Full Text Available Bacterial endosymbionts have been associated with arthropods and large number of the insect species show interaction with such bacteria. Different approaches have been used to understand such symbiont- host interactions. The whitefly, Bemisia tabaci, a highly invasive agricultural pest, harbors as many as seven different bacterial endosymbionts. These bacterial endosymbionts are known to provide various nutritional, physiological, environmental and evolutionary benefits to its insect host. In this study, we have tried to compare two techniques, Polymerase chain reaction (PCR and Flourescence in situ Hybridisation (FISH commonly used for identification and localization of bacterial endosymbionts in B. tabaci as it harbors one of the highest numbers of endosymbionts which have helped it in becoming a successful global invasive agricultural pest. The amplified PCR products were observed as bands on agarose gel by electrophoresis while the FISH samples were mounted on slides and observed under confocal microscope. Analysis of results obtained by these two techniques revealed the advantages of FISH over PCR. On a short note, performing FISH, using LNA probes proved to be more sensitive and informative for identification as well as localization of bacterial endosymbionts in B. tabaci than relying on PCR. This study would help in designing more efficient experiments based on much reliable detection procedure and studying the role of endosymbionts in insects.

  11. ´Candidatus Midichloria mitochondrii´, an endosymbiont of the tick Ixodes ricinus with a unique intramitochondrial lifestyle

    Czech Academy of Sciences Publication Activity Database

    Sassera, D.; Beninati, T.; Bandi, C.; Bouman, Edwin Arien Poul; Sacchi, L.; Fabbi, M.; Lo, N.

    2006-01-01

    Roč. 56, č. 11 (2006), s. 2535-2540 ISSN 1466-5026 R&D Projects: GA ČR GA206/04/0751 Institutional research plan: CEZ:AV0Z60220518 Keywords : Ixodes ricinus * endosymbiont * intramitochondrial Subject RIV: EH - Ecology, Behaviour Impact factor: 2.662, year: 2006

  12. The candidate phylum 'Termite Group 1' of bacteria: phylogenetic diversity, distribution, and endosymbiont members of various gut flagellated protists.

    Science.gov (United States)

    Ohkuma, Moriya; Sato, Tomoyuki; Noda, Satoko; Ui, Sadaharu; Kudo, Toshiaki; Hongoh, Yuichi

    2007-06-01

    The candidate phylum 'Termite Group 1' (TG1) of bacteria, which is abundant in termite guts but has no culturable representative, was investigated with respect to the in situ localization, distribution, and diversity. Based on the 16S rRNA gene sequence analyses and FISH in termite guts, a number of lineages of TG1 members were identified as endosymbionts of a variety of gut flagellated protists from the orders Trichonymphida, Cristamonadida, and Oxymonadida that are mostly unique to termites. However, the survey in various environments using specific PCR primers revealed that TG1 members were also present in termites, a cockroach, and the bovine rumen that typically lack these protist orders. Most of the TG1 members from gut flagellates, termites, cockroaches, and the rumen formed a monophyletic subcluster that showed a shallow branching pattern in the phylogenetic tree, suggesting their recent diversification. Although endosymbionts of the same protist genera tended to be closely related, the endosymbiont lineages were often independent of the higher level classifications of their host protist and were dispersed in the phylogenetic tree. It appears that their cospeciation is not the sole rule for the diversification of TG1 members of endosymbionts.

  13. A community change in the algal endosymbionts of a scleractinian coral following a natural bleaching event : field evidence of acclimatization

    NARCIS (Netherlands)

    Jones, A. M.; Berkelmans, R.; van Oppen, M. J. H.; Mieog, J. C.; Sinclair, W.

    2008-01-01

    The symbiosis between reef-building corals and their algal endosymbionts (zooxanthellae of the genus Symbiodinium) is highly sensitive to temperature stress, which makes coral reefs vulnerable to climate change. Thermal tolerance in corals is known to be substantially linked to the type of

  14. Phylogenetic relationships of Francisella-like endosymbionts detected in two species of Amblyomma from snakes in Thailand

    Czech Academy of Sciences Publication Activity Database

    Sumrandee, C.; Hirunkanokpun, S.; Grubhoffer, Libor; Baimai, V.; Trinachartvanit, W.; Ahantarig, A.

    2014-01-01

    Roč. 5, č. 1 (2014), s. 29-32 ISSN 1877-959X Institutional support: RVO:60077344 Keywords : tick * Francisella-like endosymbiont * Amblyomma varanense * Amblyomma helvolum * snake * Thailand Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.718, year: 2014

  15. 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.

  16. 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.

  17. 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.

  18. Host gene response to endosymbiont and pathogen in the cereal weevil Sitophilus oryzae

    Directory of Open Access Journals (Sweden)

    Vigneron Aurélien

    2012-01-01

    Full Text Available Abstract Background Insects thriving on nutritionally poor habitats have integrated mutualistic intracellular symbiotic bacteria (endosymbionts in a bacteria-bearing tissue (the bacteriome that isolates the endosymbionts and protects them against a host systemic immune response. Whilst the metabolic and physiological features of long-term insect associations have been investigated in detail over the past decades, cellular and immune regulations that determine the host response to endosymbionts and pathogens have attracted interest more recently. Results To investigate bacteriome cellular specificities and weevil immune responses to bacteria, we have constructed and sequenced 7 cDNA libraries from Sitophilus oryzae whole larvae and bacteriomes. Bioinformatic analysis of 26,886 ESTs led to the generation of 8,941 weevil unigenes. Based on in silico analysis and on the examination of genes involved in the cellular pathways of potential interest to intracellular symbiosis (i.e. cell growth and apoptosis, autophagy, immunity, we have selected and analyzed 29 genes using qRT-PCR, taking into consideration bacteriome specificity and symbiosis impact on the host response to pathogens. We show that the bacteriome tissue accumulates transcripts from genes involved in cellular development and survival, such as the apoptotic inhibitors iap2 and iap3, and endosomal fusion and trafficking, such as Rab7, Hrs, and SNARE. As regards our investigation into immunity, we first strengthen the bacteriome immunomodulation previously reported in S. zeamais. We show that the sarcotoxin, the c-type lysozyme, and the wpgrp2 genes are downregulated in the S. oryzae bacteriome, when compared to aposymbiotic insects and insects challenged with E. coli. Secondly, transcript level comparison between symbiotic and aposymbiotic larvae provides evidence that the immune systemic response to pathogens is decreased in symbiotic insects, as shown by the relatively high expression of

  19. 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.

  20. Bacterial endosymbionts in field-collected samples of Trialeurodes sp. nr. abutiloneus (Hemiptera: Aleyrodidae).

    Science.gov (United States)

    Cass, Bodil N; Mozes-Daube, Netta; Iasur-Kruh, Lilach; Bondy, Elizabeth C; Kelly, Suzanne E; Hunter, Martha S; Zchori-Fein, Einat

    2014-01-01

    Facultative bacterial endosymbionts are common, influential associates of arthropods, yet their movement among host species has not been well documented. Plant-mediated transmission of Rickettsia has been shown for the whitefly Bemisia tabaci. Bemisia tabaci in USA cotton fields harbors the secondary symbionts Rickettsia and Hamiltonella, and co-occurs with Trialeurodes sp. nr. abutiloneus whiteflies. To determine whether symbionts may be shared, the microbial diversity of these whiteflies on cotton across the USA was analyzed. Trialeurodes sp. nr. abutiloneus bore Portiera, Pseudomonas, Serratia, Arsenophonus and Wolbachia. No Rickettsia or Hamiltonella were detected. These results provide no evidence for horizontal transmission of symbionts between these whitefly genera. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  1. Identification and phylogenetic analysis of heme synthesis genes in trypanosomatids and their bacterial endosymbionts.

    Directory of Open Access Journals (Sweden)

    João M P Alves

    Full Text Available It has been known for decades that some insect-infecting trypanosomatids can survive in culture without heme supplementation while others cannot, and that this capability is associated with the presence of a betaproteobacterial endosymbiont in the flagellate's cytoplasm. However, the specific mechanisms involved in this process remained obscure. In this work, we sequence and phylogenetically analyze the heme pathway genes from the symbionts and from their hosts, as well as from a number of heme synthesis-deficient Kinetoplastida. Our results show that the enzymes responsible for synthesis of heme are encoded on the symbiont genomes and produced in close cooperation with the flagellate host. Our evidence suggests that this synergistic relationship is the end result of a history of extensive gene loss and multiple lateral gene transfer events in different branches of the phylogeny of the Trypanosomatidae.

  2. 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

  3. Bacterial DNA sifted from the Trichoplax adhaerens (Animalia: Placozoa) genome project reveals a putative rickettsial endosymbiont.

    Science.gov (United States)

    Driscoll, Timothy; Gillespie, Joseph J; Nordberg, Eric K; Azad, Abdu F; Sobral, Bruno W

    2013-01-01

    Eukaryotic genome sequencing projects often yield bacterial DNA sequences, data typically considered as microbial contamination. However, these sequences may also indicate either symbiont genes or lateral gene transfer (LGT) to host genomes. These bacterial sequences can provide clues about eukaryote-microbe interactions. Here, we used the genome of the primitive animal Trichoplax adhaerens (Metazoa: Placozoa), which is known to harbor an uncharacterized Gram-negative endosymbiont, to search for the presence of bacterial DNA sequences. Bioinformatic and phylogenomic analyses of extracted data from the genome assembly (181 bacterial coding sequences [CDS]) and trace read archive (16S rDNA) revealed a dominant proteobacterial profile strongly skewed to Rickettsiales (Alphaproteobacteria) genomes. By way of phylogenetic analysis of 16S rDNA and 113 proteins conserved across proteobacterial genomes, as well as identification of 27 rickettsial signature genes, we propose a Rickettsiales endosymbiont of T. adhaerens (RETA). The majority (93%) of the identified bacterial CDS belongs to small scaffolds containing prokaryotic-like genes; however, 12 CDS were identified on large scaffolds comprised of eukaryotic-like genes, suggesting that T. adhaerens might have recently acquired bacterial genes. These putative LGTs may coincide with the placozoan's aquatic niche and symbiosis with RETA. This work underscores the rich, and relatively untapped, resource of eukaryotic genome projects for harboring data pertinent to host-microbial interactions. The nature of unknown (or poorly characterized) bacterial species may only emerge via analysis of host genome sequencing projects, particularly if these species are resistant to cell culturing, as are many obligate intracellular microbes. Our work provides methodological insight for such an approach.

  4. Transfer of a parthenogenesis-inducing Wolbachia endosymbiont derived from Trichogramma dendrolimi into Trichogramma evanescens.

    Science.gov (United States)

    Watanabe, Masaya; Kageyama, Daisuke; Miura, Kazuki

    2013-01-01

    Wolbachia, which are maternally transmitted endosymbionts, are considered to have moved horizontally between invertebrate hosts multiple times. However, it is not well understood how easily Wolbachia are transmitted horizontally between different hosts and how frequently horizontally-transmitted Wolbachia become established in their new hosts. We transferred a parthenogenesis-inducing Wolbachia endosymbiont derived from the parasitic wasp Trichogramma dendrolimi to Trichogramma evanescens. Specifically, Wolbachia was cultivated in a mosquito cell line and the Wolbachia-infected cells were microinjected into uninfected T. evanescens. Among 276 pupae inoculated with Wolbachia-infected cells, 65 adults emerged (G0). Diagnostic PCR demonstrated that 25 of 37 G0 females (68%) were Wolbachia-positive. Among isofemale lines established from G0 females, the proportions of infected lines were 80% (20 of 25) in G1 and 100% (18 of 18) in G2. In an isofemale line, infection was stably maintained for more than 10 generations. These results indicate invasion of Wolbachia into the germline of the recipient insect. Quantitative PCR demonstrated that the Wolbachia titer in the recipient host was significantly lower than that in the native host. The absence or very low number, if any, of parthenogenetically-reproducing individuals in the recipient host may be caused by the low Wolbachia titer. The Wolbachia titer in the recipients was lower in G11 than in G5, suggesting a decline in the density. Together with a previous report, our study may imply that Wolbachia in Trichogramma species are highly adapted to their hosts, which hinders robust expression of the Wolbachia phenotype in non-native host species. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. [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.

  6. The effect of phosphate deficiency on quorum sensing signaling pathway of Sinorhizobium meliloti

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    Najmeh Pakdaman

    2015-02-01

    Full Text Available   Introduction : Phosphorus is one of the most essential macroelements for bacterial cells. Since phosphate (PO4-3 limitation is frequently encountered in soils, bacteria developed some mechanisms in response to this sever condition. Phosphate transporter (PstS and proteins involved in quorum sensing (QS signaling pathway are affected by mediating PhoB, response regulator, following phosphate starvation. QS system of Sinorhizobium meliloti composed of at least three genes of sinI (autoinducer synthase, sinR and expR (autoinducer activated receptor which involved in its free living and symbiotic functions .   Materials and method s: The optical density (OD600 of different S. meliloti transformed strains carrying pLK004 (a pstS promoter-egfp fusion, pLK64 (a sinI promoter-egfp fusion, pLK65 (a sinR promoter-egfp fusion, pLK66 (an expR promoter-egfp fusion and control (promoterless-egfp fusion plasmids were read under different phosphate concentrations of 0.1 (phosphate deficiency, 0.5 and 2 mM (sufficient phosphate at several time points of 16, 24 and 40h. The promoter activity of different genes of pstS, sinI, sinR and expR were measured as emitted fluorescence per bacterial cell density (OD600 under different phosphate concentrations .   Results : By reducing phosphate concentration in the medium, the growth rate of transformed bacteria decreased, especially at 40h. The promoter activity of pstS, sinI and sinR, but not expR, genes was activated following phosphate starvation .   Discussion and conclusion : S. meliloti can upregulate PstS to partly compensate phosphate deficiency in the environment. The gene of sinR is also activated in a PhoB dependent manner as phosphate starvation is encountered. SinR is the activator of sinI, so the upregulation of QS pathway under phosphate deficiency may be facilitate free living and symbiotic bacterial functions .

  7. Exploring the symbiotic pangenome of the nitrogen-fixing bacterium Sinorhizobium meliloti

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    Daligault Hajnalka

    2011-05-01

    Full Text Available Abstract Background Sinorhizobium meliloti is a model system for the studies of symbiotic nitrogen fixation. An extensive polymorphism at the genetic and phenotypic level is present in natural populations of this species, especially in relation with symbiotic promotion of plant growth. AK83 and BL225C are two nodule-isolated strains with diverse symbiotic phenotypes; BL225C is more efficient in promoting growth of the Medicago sativa plants than strain AK83. In order to investigate the genetic determinants of the phenotypic diversification of S. meliloti strains AK83 and BL225C, we sequenced the complete genomes for these two strains. Results With sizes of 7.14 Mbp and 6.97 Mbp, respectively, the genomes of AK83 and BL225C are larger than the laboratory strain Rm1021. The core genome of Rm1021, AK83, BL225C strains included 5124 orthologous groups, while the accessory genome was composed by 2700 orthologous groups. While Rm1021 and BL225C have only three replicons (Chromosome, pSymA and pSymB, AK83 has also two plasmids, 260 and 70 Kbp long. We found 65 interesting orthologous groups of genes that were present only in the accessory genome, consequently responsible for phenotypic diversity and putatively involved in plant-bacterium interaction. Notably, the symbiosis inefficient AK83 lacked several genes required for microaerophilic growth inside nodules, while several genes for accessory functions related to competition, plant invasion and bacteroid tropism were identified only in AK83 and BL225C strains. Presence and extent of polymorphism in regulons of transcription factors involved in symbiotic interaction were also analyzed. Our results indicate that regulons are flexible, with a large number of accessory genes, suggesting that regulons polymorphism could also be a key determinant in the variability of symbiotic performances among the analyzed strains. Conclusions In conclusions, the extended comparative genomics approach revealed a

  8. 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.

  9. 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...

  10. [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.

  11. 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...

  12. Altered susceptibility to infection by Sinorhizobium meliloti and Nectria haematococca in alfalfa roots with altered cell cycle.

    Science.gov (United States)

    Woo, H-H; Hirsch, A M; Hawes, M C

    2004-07-01

    Most infections of plant roots are initiated in the region of elongation; the mechanism for this tissue-specific localization pattern is unknown. In alfalfa expressing PsUGT1 antisense mRNA under the control of the cauliflower mosaic virus (CaMV) 35S promoter, the cell cycle in roots is completed in 48 h instead of 24 h, and border cell number is decreased by more than 99%. These plants were found to exhibit increased root-tip infection by a fungal pathogen and reduced nodule formation by a bacterial symbiont. Thus, the frequency of infection in the region of elongation by Nectria haematocca was unaffected, but infection of the root tip was increased by more than 90%; early stages of Sinorhizobium meliloti infection and nodule morphology were normal, but the frequency of nodulation was fourfold lower than in wild-type roots.

  13. An integrated approach to functional genomics: construction of a novel reporter gene fusion library for Sinorhizobium meliloti.

    Science.gov (United States)

    Cowie, Alison; Cheng, Jiujun; Sibley, Christopher D; Fong, Ying; Zaheer, Rahat; Patten, Cheryl L; Morton, Richard M; Golding, G Brian; Finan, Turlough M

    2006-11-01

    As a means of investigating gene function, we developed a robust transcription fusion reporter vector to measure gene expression in bacteria. The vector, pTH1522, was used to construct a random insert library for the Sinorhizobium meliloti genome. pTH1522 replicates in Escherichia coli and can be transferred to, but cannot replicate in, S. meliloti. Homologous recombination of the DNA fragments cloned in pTH1522 into the S. meliloti genome generates transcriptional fusions to either the reporter genes gfp(+) and lacZ or gusA and rfp, depending on the orientation of the cloned fragment. Over 12,000 fusion junctions in 6,298 clones were identified by DNA sequence analysis, and the plasmid clones were recombined into S. meliloti. Reporter enzyme activities following growth of these recombinants in complex medium (LBmc) and in minimal medium with glucose or succinate as the sole carbon source allowed the identification of genes highly expressed under one or more growth condition and those expressed at very low to background levels. In addition to generating reporter gene fusions, the vector allows Flp recombinase-directed deletion formation and gene disruption, depending on the nature of the cloned fragment. We report the identification of genes essential for growth on complex medium as deduced from an inability to recover recombinants from pTH1522 clones that carried fragments internal to gene or operon transcripts. A database containing all the gene expression activities together with a web interface showing the precise locations of reporter fusion junctions has been constructed (www.sinorhizobium.org).

  14. 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 ...

  15. 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 ...

  16.  Serial replacement of diatom endosymbiont in two freshwater dinoflagellates, Peridiniopsis spp., (Peridiniales, Dinophyceae)

    DEFF Research Database (Denmark)

    Takano, Y.; Hansen, Gert; Fujita, D.

    2008-01-01

    structure and possessed an endosymbiotic diatom. The diatom endosymbiont, which contained a eukaryotic nucleus, chloroplasts and mitochondria, was separated from the dinoflagellate cytoplasm by a single unit membrane. The dinoflagellate cytoplasm contained a triple-membrane-bound eyespot, in addition......Two freshwater armoured dinoflagellates, Peridiniopsis cf. kevei from Japan and Peridiniopsis penardii from Japan and Italy, were examined by means of light, scanning and transmission electron microscopy. Morphological studies indicated that the two dinoflagellates had similar type of cellular...

  17. Waterlogging tolerance, tissue nitrogen and oxygen transport in the forage legume Melilotus siculus: a comparison of nodulated and nitrate-fed plants.

    Science.gov (United States)

    Konnerup, Dennis; Toro, Guillermo; Pedersen, Ole; Colmer, Timothy David

    2018-01-17

    Soil waterlogging adversely impacts most plants. Melilotus siculus is a waterlogging-tolerant annual forage legume, but data were lacking for the effects of root-zone hypoxia on nodulated plants reliant on N2 fixation. The aim was to compare the waterlogging tolerance and physiology of M. siculus reliant on N2 fixation or with access to NO3-. A factorial experiment imposed treatments of water level (drained or waterlogged), rhizobia (nil or inoculated) and mineral N supply (nil or 11 mm NO3-) for 21 d on plants in pots of vermiculite in a glasshouse. Nodulation, shoot and root growth and tissue N were determined. Porosity (gas volume per unit tissue volume) and respiration rates of root tissues and nodules, and O2 microelectrode profiling across nodules, were measured in a second experiment. Plants inoculated with the appropriate rhizobia, Ensifer (syn. Sinorhizobium) medicae, formed nodules. Nodulated plants grew as well as plants fed NO3-, both in drained and waterlogged conditions. The growth and total N content of nodulated plants (without any NO3- supplied) indicated N2 fixation. Respiration rates (mass basis) were highest in nodules and root tips and lowest in basal root tissues. Secondary aerenchyma (phellem) formed along basal root parts and a thin layer of this porous tissue also covered nodules, which together enhanced gas-phase diffusion of O2 to the nodules; O2 was below detection within the infected zone of the nodule interior. Melilotus siculus reliant on N2 fixation grew well both in drained and waterlogged conditions, and had similar tissue N concentrations. In waterlogged conditions the relatively high respiration rates of nodules must rely on O2 movement via the aerenchymatous phellem in hypocotyl, roots and the outer tissue layers of nodules. © The Author(s) 2018. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. A study of chlorophyll-like and phycobilin pigments in the C endosymbiont of the apple-snail pomacea canaliculata.

    Science.gov (United States)

    Vega, Israel A; Dellagnola, Federico A; Hurst, Jorge A; Godoy, Martín S; Castro-Vazquez, Alfredo

    2012-08-01

    Pigments present in the brown-greenish C morph of an intracellular endosymbiont of Pomacea canaliculata were investigated. Acetone extracts of the endosymbiotic corpuscles showed an absorption spectrum similar to that of chlorophylls. Three fractions obtained from silica gel column chromatography of the acetone extracts (C(I), C(II), and C(III)), were studied by positive ion fast atom bombardment-mass spectrometry (FAB-MS) and hydrogen-nuclear magnetic resonance (H-NMR). Results indicated the presence of (1) a sterol in the yellow colored C(I) fraction; (2) a mixture ofpheophorbides a and b in the major green fraction, C(II); and (3) a modified pheophorbide a in the smaller green fraction, C(III). Aqueous extracts of the C endosymbiont did not show evidence of the occurrence of C-phycocyanin, allophycocyanin or phycoerithrin (light absorption, fluorescence emission, and electrophoresis of the protein moieties) while cyanobacterial cells (Nostoc sp.) showed evidence of C-phycocyanin and allophycocyanin. The possible phylogenetic and functional significance of the pigments present in the C endosymbiont is discussed.

  19. 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.

  20. 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 ...

  1. 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 ...

  2. 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 ...

  3. 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 ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. 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 ...

  8. 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 ...

  9. 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.

  10. 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.

  11. 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.

  12. 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 ...

  13. 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.

  14. 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

  15. 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 ...

  16. 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)

  17. 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.

  18. 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.

  19. 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 ...

  20. 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.

  1. 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 ...

  2. 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 ...

  3. 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.

  4. 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 ...

  5. 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)

  6. 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 ...

  7. 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 ...

  8. 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

  9. 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.

  10. The cyanobacterial endosymbiont of the unicellular algae Rhopalodia gibba shows reductive genome evolution

    Directory of Open Access Journals (Sweden)

    Lockhart Peter J

    2008-01-01

    Full Text Available Abstract Background Bacteria occur in facultative association and intracellular symbiosis with a diversity of eukaryotic hosts. Recently, we have helped to characterise an intracellular nitrogen fixing bacterium, the so-called spheroid body, located within the diatom Rhopalodia gibba. Spheroid bodies are of cyanobacterial origin and exhibit features that suggest physiological adaptation to their intracellular life style. To investigate the genome modifications that have accompanied the process of endosymbiosis, here we compare gene structure, content and organisation in spheroid body and cyanobacterial genomes. Results Comparison of the spheroid body's genome sequence with corresponding regions of near free-living relatives indicates that multiple modifications have occurred in the endosymbiont's genome. These include localised changes that have led to elimination of some genes. This gene loss has been accompanied either by deletion of the respective DNA region or replacement with non-coding DNA that is AT rich in composition. In addition, genome modifications have led to the fusion and truncation of genes. We also report that in the spheroid body's genome there is an accumulation of deleterious mutations in genes for cell wall biosynthesis and processes controlled by transposases. Interestingly, the formation of pseudogenes in the spheroid body has occurred in the presence of intact, and presumably functional, recA and recF genes. This is in contrast to the situation in most investigated obligate intracellular bacterium-eukaryote symbioses, where at least either recA or recF has been eliminated. Conclusion Our analyses suggest highly specific targeting/loss of individual genes during the process of genome reduction and establishment of a cyanobacterial endosymbiont inside a eukaryotic cell. Our findings confirm, at the genome level, earlier speculation on the obligate intracellular status of the spheroid body in Rhopalodia gibba. This

  11. ACUTE TOXICITY OF METALS: NICKEL AND ZINC TO PARAMECIUM BURSARIA AND ITS ENDOSYMBIONTS

    Directory of Open Access Journals (Sweden)

    Patrycja Zagata

    2015-02-01

    Full Text Available Paramecium bursaria is an unicellular organism, widely distributed in the freshwater environment, where heavy metals are common contaminants. The ciliates, also including Paramecium bursaria, are a very abundant group in aquatic ecosystems, what makes them effective biological indicators of water pollutants. Paramecium bursaria is the only Paramecium which has evolved a mutualistic relationship with algae and it harbors these endosymbionts in its own cytoplasm. The algae are also very effective bioindicators of some pollutants because of their ability to biosorption and bioaccumulation of heavy metals. The aim of this study was to determine the acute toxicity of two metals’ compounds: nickel chloride (NiCl2 and zinc chloride (ZnCl2 to Paramecium bursaria and its endosymbionts. The ciliates were incubated in solutions with 5x10-8 to 5x10-2g/dm3 of NiCl2 and with 5x10-8 to 5x10-2g/dm3 of ZnCl2, at the temperature of 180C, in the light/dark conditions (12L/12D. Microscopic observations of cell divisions rate, cell shape changes as well as the swimming behavior, were conducted after 24, 48, 72 and 120 hours of incubation in the tested solutions and were compared to the control sample. Microscopic observations revealed the lethal doses for both compounds, for nickel chloride 5x10-5g/dm3 and for zinc chloride 5x10-3. These observations also revealed that in lesser concentrations than the lethal one, the slowdown and characteristic movements occur after metal addition. The PEA measurements of Fv/Fm parameter were carried out within 4 days, the first one after 24 hours of incubations. The results of this investigation has given us a view of a fluorescence efficiency by revealing that both compounds solutions can have the stimulating effect on Photosystem II, because the lowest fluorescence efficiency was measured in control samples.

  12. 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...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.;

  18. 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...

  19. 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...

  20. GroEL from the endosymbiont Buchnera aphidicola betrays the aphid by triggering plant defense

    Science.gov (United States)

    Chaudhary, Ritu; Atamian, Hagop S.; Shen, Zhouxin; Briggs, Steven P.; Kaloshian, Isgouhi

    2014-01-01

    Aphids are sap-feeding plant pests and harbor the endosymbiont Buchnera aphidicola, which is essential for their fecundity and survival. During plant penetration and feeding, aphids secrete saliva that contains proteins predicted to alter plant defenses and metabolism. Plants recognize microbe-associated molecular patterns and induce pattern-triggered immunity (PTI). No aphid-associated molecular pattern has yet been identified. By mass spectrometry, we identified in saliva from potato aphids (Macrosiphum euphorbiae) 105 proteins, some of which originated from Buchnera, including the chaperonin GroEL. Because GroEL is a widely conserved bacterial protein with an essential function, we tested its role in PTI. Applying or infiltrating GroEL onto Arabidopsis (Arabidopsis thaliana) leaves induced oxidative burst and expression of PTI early marker genes. These GroEL-induced defense responses required the known coreceptor BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1. In addition, in transgenic Arabidopsis plants, inducible expression of groEL activated PTI marker gene expression. Moreover, Arabidopsis plants expressing groEL displayed reduced fecundity of the green peach aphid (Myzus persicae), indicating enhanced resistance against aphids. Furthermore, delivery of GroEL into tomato (Solanum lycopersicum) or Arabidopsis through Pseudomonas fluorescens, engineered to express the type III secretion system, also reduced potato aphid and green peach aphid fecundity, respectively. Collectively our data indicate that GroEL is a molecular pattern that triggers PTI. PMID:24927572

  1. Plant-mediated horizontal transmission of Rickettsia endosymbiont between different whitefly species.

    Science.gov (United States)

    Li, Yi-Han; Ahmed, Muhammad Z; Li, Shao-Jian; Lv, Ning; Shi, Pei-Qiong; Chen, Xiao-Sheng; Qiu, Bao-Li

    2017-12-01

    A growing number of studies have revealed the presence of closely related endosymbionts in phylogenetically distant arthropods, indicating horizontal transmission of these bacteria. Here we investigated the interspecific horizontal transmission of Rickettsia between two globally invasive whitefly species, Bemisia tabaci MEAM1 and B. tabaci MED, via cotton plants. We found both scattered and confined distribution patterns of Rickettsia in these whiteflies. After entering cotton leaves, Rickettsia was restricted to the leaf phloem vessels and could be taken up by both species of the Rickettsia-free whitefly adults, but only the scattered pattern was observed in the recipient whiteflies. Both the relative quantity of Rickettsia and the efficiency of transmitting Rickettsia into cotton leaves were significantly higher in MEAM1 females than in MED females. The retention time of Rickettsia transmitted from MEAM1 into cotton leaves was at least 5 days longer than that of MED. Phylogenetic analysis based on 16S rRNA and gltA genes confirmed that the Rickettsia extracted from the donor MEAM1, the cotton leaves, the recipient MEAM1 and the recipient MED were all identical. We conclude that cotton plants can mediate horizontal transmission of Rickettsia between different insect species, and that the transmission dynamics of Rickettsia vary with different host whitefly species. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. A new cytogenetic mechanism for bacterial endosymbiont-induced parthenogenesis in Hymenoptera

    Science.gov (United States)

    Adachi-Hagimori, Tetsuya; Miura, Kazuki; Stouthamer, Richard

    2008-01-01

    Vertically transmitted endosymbiotic bacteria, such as Wolbachia, Cardinium and Rickettsia, modify host reproduction in several ways to facilitate their own spread. One such modification results in parthenogenesis induction, where males, which are unable to transmit the bacteria, are not produced. In Hymenoptera, the mechanism of diploidization due to Wolbachia infection, known as gamete duplication, is a post-meiotic modification. During gamete duplication, the meiotic mechanism is normal, but in the first mitosis the anaphase is aborted. The two haploid sets of chromosomes do not separate and thus result in a single nucleus containing two identical sets of haploid chromosomes. Here, we outline an alternative cytogenetic mechanism for bacterial endosymbiont-induced parthenogenesis in Hymenoptera. During female gamete formation in Rickettsia-infected Neochrysocharis formosa (Westwood) parasitoids, meiotic cells undergo only a single equational division followed by the expulsion of a single polar body. This absence of meiotic recombination and reduction corresponds well with a non-segregation pattern in the offspring of heterozygous females. We conclude that diploidy in N. formosa is maintained through a functionally apomictic cloning mechanism that differs entirely from the mechanism induced by Wolbachia. PMID:18713719

  3. Wolbachia endosymbionts in haplodiploid and diploid scolytine beetles (Coleoptera: Curculionidae: Scolytinae).

    Science.gov (United States)

    Kawasaki, Yuuki; Schuler, Hannes; Stauffer, Christian; Lakatos, Ferenc; Kajimura, Hisashi

    2016-05-19

    Haplodiploidy is a sex determination system in which fertilized diploid eggs develop into females and unfertilized haploid eggs develop into males. The evolutionary explanations for this phenomenon include the possibility that haplodiploidy can be reinforced by infection with endosymbiotic bacteria, such as Wolbachia. The subfamily Scolytinae contains species with haplodiploid and diploid sex determination systems. Thus, we studied the association with Wolbachia in 12 diploid and 11 haplodiploid scolytine beetles by analyzing wsp and multilocus sequence typing (MLST) of five loci in this endosymbiont. Wolbachia genotypes were compared with mitochondrial (COI) and nuclear (EF) genotypes in the scolytines. Eight of the 23 scolytine species were infected with Wolbachia, with haplodiploids at significantly higher rates than diploid species. Cloning and sequencing detected multiple infections with up to six Wolbachia strains in individual species. Phylogenetic analyses of wsp and five MLST genes revealed different Wolbachia strains in scolytines. Comparisons between the beetle and Wolbachia phylogenies revealed that closely related beetles were infected with genetically different Wolbachia strains. These results suggest the horizontal transmission of multiple Wolbachia strains between scolytines. We discuss these results in terms of the evolution of different sex determination systems in scolytine beetles. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Induction of Maltose Release by Light in the Endosymbiont Chlorella variabilis of Paramecium bursaria.

    Science.gov (United States)

    Shibata, Aika; Takahashi, Fumio; Kasahara, Masahiro; Imamura, Nobutaka

    2016-11-01

    The endosymbiotic green algae of Paramecium bursaria are known to release a photosynthate to the host cells. The endosymbiont Chlorella variabilis F36-ZK isolated in Japan releases maltose under acidic conditions, and such release requires both light and low pH. However, whether photosynthate release is due to light sensing by photoreceptors or is merely a consequence of active photosynthesis is unclear. Herein, we studied the effect of light on maltose release from C. variabilis F36-ZK; we measured maltose release using a combination of 1-phenyl-3-methyl-5-pyrazolone derivative and 14 C-tracer methods. Blue (450nm) or red (around 600nm) light was most effective to stimulate maltose release. This suggests that the photosynthetic pathway probably participates in maltose release, because the effective wavelength corresponds to the absorption spectrum of chlorophyll. Furthermore, maltose release was slightly affected by addition of a photosynthetic inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, but was abolished by another inhibitor of photosynthesis, 2,5-dibromo-6-isopropyl-3-methyl-1,4-benzoquinone, suggesting that electron flow through photosystem I may be more involved in maltose release. Interestingly, starving F36-ZK cells cultured under prolonged dark conditions did not release maltose but retained their photosynthetic capacity. Our results thus show that maltose release is regulated by light and cellular conditions in endosymbiotic Chlorella. Copyright © 2016. Published by Elsevier GmbH.

  5. From endosymbionts to host communities: factors determining the reproductive success of arthropod vectors.

    Science.gov (United States)

    Messika, Irit; Garrido, Mario; Kedem, Hadar; China, Victor; Gavish, Yoni; Dong, Qunfeng; Fuqua, Clay; Clay, Keith; Hawlena, Hadas

    2017-08-01

    Elucidating the factors determining reproductive success has challenged scientists since Darwin, but the exact pathways that shape the evolution of life history traits by connecting extrinsic (e.g., landscape structure) and intrinsic (e.g., female's age and endosymbionts) factors and reproductive success have rarely been studied. Here we collected female fleas from wild rodents in plots differing in their densities and proportions of the most dominant rodent species. We then combined path analysis and model selection approaches to explore the network of effects, ranging from micro to macroscales, determining the reproductive success of these fleas. Our results suggest that female reproductive success is directly and positively associated with their infection by Mycoplasma bacteria and their own body mass, and with the rodent species size and total density. In addition, we found evidence for indirect effects of rodent sex and rodent community diversity on female reproductive success. These results highlight the importance of exploring interrelated factors across organization scales while studying the reproductive success of wild organisms, and they have implications for the control of vector-borne diseases.

  6. Dietary saccharides and sweet tastants have differential effects on colonization of Drosophila oocytes by Wolbachia endosymbionts

    Directory of Open Access Journals (Sweden)

    Moises Camacho

    2017-07-01

    Full Text Available Wolbachia bacteria are widespread, maternally transmitted endosymbionts of insects. Maintenance of sufficient Wolbachia titer in maternal germline cells is required for transmission efficacy. The mechanisms that regulate Wolbachia titer are not well understood; however, dietary sucrose was reported to elevate oocyte Wolbachia titer in Drosophila melanogaster whereas dietary yeast decreased oocyte titer. To further investigate how oocyte Wolbachia titer is controlled, this study analyzed the response of wMel Wolbachia to diets enriched in an array of natural sugars and other sweet tastants. Confocal imaging of D. melanogaster oocytes showed that food enriched in dietary galactose, lactose, maltose and trehalose elevated Wolbachia titer. However, oocyte Wolbachia titers were unaffected by exposure to the sweet tastants lactulose, erythritol, xylitol, aspartame and saccharin as compared to the control. Oocyte size was generally non-responsive to the nutrient-altered diets. Ovary size, however, was consistently smaller in response to all sugar- and sweetener-enriched diets. Furthermore, most dietary sugars administered in tandem with dietary yeast conferred complete rescue of oocyte titer suppression by yeast. All diets dually enriched in yeast and sugar also rescued yeast-associated ovary volume changes. This indicates oocyte colonization by Wolbachia to be a nutritionally sensitive process regulated by multiple mechanistic inputs.

  7. Elongation factor-P at the crossroads of the host-endosymbiont interface.

    Science.gov (United States)

    Rajkovic, Andrei; Witzky, Anne; Navarre, William; Darwin, Andrew J; Ibba, Michael

    2015-09-23

    Elongation factor P (EF-P) is an ancient bacterial translational factor that aids the ribosome in polymerizing oligo-prolines. EF-P structurally resembles tRNA and binds in-between the exit and peptidyl sites of the ribosome to accelerate the intrinsically slow reaction of peptidyl-prolyl bond formation. Recent studies have identified in separate organisms, two evolutionarily convergent EF-P post-translational modification systems (EPMS), split predominantly between gammaproteobacteria, and betaproteobacteria. In both cases EF-P receives a post-translational modification, critical for its function, on a highly conserved residue that protrudes into the peptidyl-transfer center of the ribosome. EPMSs are comprised of a gene(s) that synthesizes the precursor molecule used in modifying EF-P, and a gene(s) encoding an enzyme that reacts with the precursor molecule to catalyze covalent attachment to EF-P. However, not all organisms genetically encode a complete EPMS. For instance, some symbiotic bacteria harbor efp and the corresponding gene that enzymatically attaches the modification, but lack the ability to synthesize the substrate used in the modification reaction. Here we highlight the recent discoveries made regarding EPMSs, with a focus on how these incomplete modification pathways shape or have been shaped by the endosymbiont-host relationship.

  8. Phylogenetic distribution and evolutionary pattern of an α-proteobacterial small RNA gene that controls polyhydroxybutyrate accumulation in Sinorhizobium meliloti.

    Science.gov (United States)

    Lagares, Antonio; Roux, Indra; Valverde, Claudio

    2016-06-01

    It has become clear that sRNAs play relevant regulatory functions in bacteria. However, a comprehensive understanding of their biological roles considering evolutionary aspects has not been achieved for most of them. Thus, we have characterized the evolutionary and phylogenetic aspects of the Sinorhizobium meliloti mmgR gene encoding the small RNA MmgR, which has been recently reported to be involved in the regulation of polyhydroxybutyrate accumulation in this bacterium. We constructed a covariance model from a multiple sequence and structure alignment of mmgR close homologs that allowed us to extend the search and to detect further remote homologs of the sRNA gene. From our results, mmgR seemed to evolve from a common ancestor of the α-proteobacteria that diverged from the order of Rickettsiales. We have found mmgR homologs in most current species of α-proteobacteria, with a few exceptions in which genomic reduction events or gene rearrangements seem to explain its absence. Furthermore, a strong microsyntenic relationship was found between a large set of mmgR homologs and homologs of a gene encoding a putative N-formyl glutamate amidohydrolase (NFGAH) that allowed us to trace back the evolutionary path of this group of mmgR orthologs. Among them, structure and sequence traits have been completely conserved throughout evolution, namely a Rho-independent terminator and a 10-mer (5'-UUUCCUCCCU-3') that is predicted to remain in a single-stranded region of the sRNA. We thus propose the definition of the new family of α-proteobacterial sRNAs αr8, as well as the subfamily αr8s1 which encompass S. meliloti mmgR orthologs physically linked with the downstream open reading frame encoding a putative NFGAH. So far, mmgR is the trans-encoded small RNA with the widest phylogenetic distribution of well recognized orthologs among α-proteobacteria. Expression of the expected MmgR transcript in rhizobiales other than S. meliloti (Sinorhizobium fredii, Rhizobium

  9. 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...

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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...

  15. 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 ...

  16. 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)

  17. 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...

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Glucose-Induced Trophic Shift in an Endosymbiont Dinoflagellate with Physiological and Molecular Consequences.

    Science.gov (United States)

    Xiang, Tingting; Jinkerson, Robert E; Clowez, Sophie; Tran, Cawa; Krediet, Cory J; Onishi, Masayuki; Cleves, Phillip A; Pringle, John R; Grossman, Arthur R

    2018-02-01

    Interactions between the dinoflagellate endosymbiont Symbiodinium and its cnidarian hosts (e.g. corals, sea anemones) are the foundation of coral-reef ecosystems. Carbon flow between the partners is a hallmark of this mutualism, but the mechanisms governing this flow and its impact on symbiosis remain poorly understood. We showed previously that although Symbiodinium strain SSB01 can grow photoautotrophically, it can grow mixotrophically or heterotrophically when supplied with Glc, a metabolite normally transferred from the alga to its host. Here we show that Glc supplementation of SSB01 cultures causes a loss of pigmentation and photosynthetic activity, disorganization of thylakoid membranes, accumulation of lipid bodies, and alterations of cell-surface morphology. We used global transcriptome analyses to determine if these physiological changes were correlated with changes in gene expression. Glc-supplemented cells exhibited a marked reduction in levels of plastid transcripts encoding photosynthetic proteins, although most nuclear-encoded transcripts (including those for proteins involved in lipid synthesis and formation of the extracellular matrix) exhibited little change in their abundances. However, the altered carbon metabolism in Glc-supplemented cells was correlated with modest alterations (approximately 2x) in the levels of some nuclear-encoded transcripts for sugar transporters. Finally, Glc-bleached SSB01 cells appeared unable to efficiently populate anemone larvae. Together, these results suggest links between energy metabolism and cellular physiology, morphology, and symbiotic interactions. However, the results also show that in contrast to many other organisms, Symbiodinium can undergo dramatic physiological changes that are not reflected by major changes in the abundances of nuclear-encoded transcripts and thus presumably reflect posttranscriptional regulatory processes. © 2018 American Society of Plant Biologists. All Rights Reserved.

  3. Bacterial Endosymbiont Localization in Hyalesthes obsoletus, the Insect Vector of Bois Noir in Vitis vinifera▿

    Science.gov (United States)

    Gonella, Elena; Negri, Ilaria; Marzorati, Massimo; Mandrioli, Mauro; Sacchi, Luciano; Pajoro, Massimo; Crotti, Elena; Rizzi, Aurora; Clementi, Emanuela; Tedeschi, Rosemarie; Bandi, Claudio; Alma, Alberto; Daffonchio, Daniele

    2011-01-01

    One emerging disease of grapevine in Europe is Bois noir (BN), a phytoplasmosis caused by “Candidatus Phytoplasma solani” and spread in vineyards by the planthopper Hyalesthes obsoletus (Hemiptera: Cixiidae). Here we present the first full characterization of the bacterial community of this important disease vector collected from BN-contaminated areas in Piedmont, Italy. Length heterogeneity PCR and denaturing gradient gel electrophoresis analysis targeting the 16S rRNA gene revealed the presence of a number of bacteria stably associated with the insect vector. In particular, symbiotic bacteria detected by PCR with high infection rates in adult individuals fell within the “Candidatus Sulcia muelleri” cluster in the Bacteroidetes and in the “Candidatus Purcelliella pentastirinorum” group in the Gammaproteobacteria, both previously identified in different leafhoppers and planthoppers. A high infection rate (81%) was also shown for another symbiont belonging to the Betaproteobacteria, designated the HO1-V symbiont. Because of the low level of 16S rRNA gene identity (80%) with the closest relative, an uncharacterized symbiont of the tick Haemaphysalis longicornis, we propose the new name “Candidatus Vidania fulgoroideae.” Other bacterial endosymbionts identified in H. obsoletus were related to the intracellular bacteria Wolbachia pipientis, Rickettsia sp., and “Candidatus Cardinium hertigii.” Fluorescent in situ hybridization coupled with confocal laser scanning microscopy and transmission electron microscopy showed that these bacteria are localized in the gut, testicles, and oocytes. As “Ca. Sulcia” is usually reported in association with other symbiotic bacteria, we propose that in H. obsoletus, it may occur in a bipartite or even tripartite relationship between “Ca. Sulcia” and “Ca. Purcelliella,” “Ca. Vidania,” or both. PMID:21183640

  4. Bacterial endosymbiont localization in Hyalesthes obsoletus, the insect vector of Bois noir in Vitis vinifera.

    Science.gov (United States)

    Gonella, Elena; Negri, Ilaria; Marzorati, Massimo; Mandrioli, Mauro; Sacchi, Luciano; Pajoro, Massimo; Crotti, Elena; Rizzi, Aurora; Clementi, Emanuela; Tedeschi, Rosemarie; Bandi, Claudio; Alma, Alberto; Daffonchio, Daniele

    2011-02-01

    One emerging disease of grapevine in Europe is Bois noir (BN), a phytoplasmosis caused by "Candidatus Phytoplasma solani" and spread in vineyards by the planthopper Hyalesthes obsoletus (Hemiptera: Cixiidae). Here we present the first full characterization of the bacterial community of this important disease vector collected from BN-contaminated areas in Piedmont, Italy. Length heterogeneity PCR and denaturing gradient gel electrophoresis analysis targeting the 16S rRNA gene revealed the presence of a number of bacteria stably associated with the insect vector. In particular, symbiotic bacteria detected by PCR with high infection rates in adult individuals fell within the "Candidatus Sulcia muelleri" cluster in the Bacteroidetes and in the "Candidatus Purcelliella pentastirinorum" group in the Gammaproteobacteria, both previously identified in different leafhoppers and planthoppers. A high infection rate (81%) was also shown for another symbiont belonging to the Betaproteobacteria, designated the HO1-V symbiont. Because of the low level of 16S rRNA gene identity (80%) with the closest relative, an uncharacterized symbiont of the tick Haemaphysalis longicornis, we propose the new name "Candidatus Vidania fulgoroideae." Other bacterial endosymbionts identified in H. obsoletus were related to the intracellular bacteria Wolbachia pipientis, Rickettsia sp., and "Candidatus Cardinium hertigii." Fluorescent in situ hybridization coupled with confocal laser scanning microscopy and transmission electron microscopy showed that these bacteria are localized in the gut, testicles, and oocytes. As "Ca. Sulcia" is usually reported in association with other symbiotic bacteria, we propose that in H. obsoletus, it may occur in a bipartite or even tripartite relationship between "Ca. Sulcia" and "Ca. Purcelliella," "Ca. Vidania," or both.

  5. Predicting the proteins of Angomonas deanei, Strigomonas culicis and their respective endosymbionts reveals new aspects of the trypanosomatidae family.

    Directory of Open Access Journals (Sweden)

    Maria Cristina Machado Motta

    Full Text Available Endosymbiont-bearing trypanosomatids have been considered excellent models for the study of cell evolution because the host protozoan co-evolves with an intracellular bacterium in a mutualistic relationship. Such protozoa inhabit a single invertebrate host during their entire life cycle and exhibit special characteristics that group them in a particular phylogenetic cluster of the Trypanosomatidae family, thus classified as monoxenics. In an effort to better understand such symbiotic association, we used DNA pyrosequencing and a reference-guided assembly to generate reads that predicted 16,960 and 12,162 open reading frames (ORFs in two symbiont-bearing trypanosomatids, Angomonas deanei (previously named as Crithidia deanei and Strigomonas culicis (first known as Blastocrithidia culicis, respectively. Identification of each ORF was based primarily on TriTrypDB using tblastn, and each ORF was confirmed by employing getorf from EMBOSS and Newbler 2.6 when necessary. The monoxenic organisms revealed conserved housekeeping functions when compared to other trypanosomatids, especially compared with Leishmania major. However, major differences were found in ORFs corresponding to the cytoskeleton, the kinetoplast, and the paraflagellar structure. The monoxenic organisms also contain a large number of genes for cytosolic calpain-like and surface gp63 metalloproteases and a reduced number of compartmentalized cysteine proteases in comparison to other TriTryp organisms, reflecting adaptations to the presence of the symbiont. The assembled bacterial endosymbiont sequences exhibit a high A+T content with a total of 787 and 769 ORFs for the Angomonas deanei and Strigomonas culicis endosymbionts, respectively, and indicate that these organisms hold a common ancestor related to the Alcaligenaceae family. Importantly, both symbionts contain enzymes that complement essential host cell biosynthetic pathways, such as those for amino acid, lipid and purine

  6. Predicting the Proteins of Angomonas deanei, Strigomonas culicis and Their Respective Endosymbionts Reveals New Aspects of the Trypanosomatidae Family

    Science.gov (United States)

    Motta, Maria Cristina Machado; Martins, Allan Cezar de Azevedo; de Souza, Silvana Sant’Anna; Catta-Preta, Carolina Moura Costa; Silva, Rosane; Klein, Cecilia Coimbra; de Almeida, Luiz Gonzaga Paula; de Lima Cunha, Oberdan; Ciapina, Luciane Prioli; Brocchi, Marcelo; Colabardini, Ana Cristina; de Araujo Lima, Bruna; Machado, Carlos Renato; de Almeida Soares, Célia Maria; Probst, Christian Macagnan; de Menezes, Claudia Beatriz Afonso; Thompson, Claudia Elizabeth; Bartholomeu, Daniella Castanheira; Gradia, Daniela Fiori; Pavoni, Daniela Parada; Grisard, Edmundo C.; Fantinatti-Garboggini, Fabiana; Marchini, Fabricio Klerynton; Rodrigues-Luiz, Gabriela Flávia; Wagner, Glauber; Goldman, Gustavo Henrique; Fietto, Juliana Lopes Rangel; Elias, Maria Carolina; Goldman, Maria Helena S.; Sagot, Marie-France; Pereira, Maristela; Stoco, Patrícia H.; de Mendonça-Neto, Rondon Pessoa; Teixeira, Santuza Maria Ribeiro; Maciel, Talles Eduardo Ferreira; de Oliveira Mendes, Tiago Antônio; Ürményi, Turán P.; de Souza, Wanderley; Schenkman, Sergio; de Vasconcelos, Ana Tereza Ribeiro

    2013-01-01

    Endosymbiont-bearing trypanosomatids have been considered excellent models for the study of cell evolution because the host protozoan co-evolves with an intracellular bacterium in a mutualistic relationship. Such protozoa inhabit a single invertebrate host during their entire life cycle and exhibit special characteristics that group them in a particular phylogenetic cluster of the Trypanosomatidae family, thus classified as monoxenics. In an effort to better understand such symbiotic association, we used DNA pyrosequencing and a reference-guided assembly to generate reads that predicted 16,960 and 12,162 open reading frames (ORFs) in two symbiont-bearing trypanosomatids, Angomonas deanei (previously named as Crithidia deanei) and Strigomonas culicis (first known as Blastocrithidia culicis), respectively. Identification of each ORF was based primarily on TriTrypDB using tblastn, and each ORF was confirmed by employing getorf from EMBOSS and Newbler 2.6 when necessary. The monoxenic organisms revealed conserved housekeeping functions when compared to other trypanosomatids, especially compared with Leishmania major. However, major differences were found in ORFs corresponding to the cytoskeleton, the kinetoplast, and the paraflagellar structure. The monoxenic organisms also contain a large number of genes for cytosolic calpain-like and surface gp63 metalloproteases and a reduced number of compartmentalized cysteine proteases in comparison to other TriTryp organisms, reflecting adaptations to the presence of the symbiont. The assembled bacterial endosymbiont sequences exhibit a high A+T content with a total of 787 and 769 ORFs for the Angomonas deanei and Strigomonas culicis endosymbionts, respectively, and indicate that these organisms hold a common ancestor related to the Alcaligenaceae family. Importantly, both symbionts contain enzymes that complement essential host cell biosynthetic pathways, such as those for amino acid, lipid and purine/pyrimidine metabolism

  7. Effect of a Sinorhizobium meliloti strain with a modified putA gene on the rhizosphere microbial community of alfalfa.

    Science.gov (United States)

    van Dillewijn, Pieter; Villadas, Pablo J; Toro, Nicolás

    2002-09-01

    The success of a rhizobial inoculant in the soil depends to a large extent on its capacity to compete against indigenous strains. M403, a Sinorhizobium meliloti strain with enhanced competitiveness for nodule occupancy, was recently constructed by introducing a plasmid containing an extra copy of a modified putA (proline dehydrogenase) gene. This strain and M401, a control strain carrying the same plasmid without the modified gene, were used as soil inoculants for alfalfa in a contained field release experiment at León, Spain. In this study, we determined the effects of these two strains on the indigenous microbial community. 16S rRNA genes were obtained from the rhizosphere of alfalfa inoculated with strain M403 or strain M401 or from noninoculated plants by amplification of DNA from soil with bacterial group-specific primers. These genes were analyzed and compared by restriction fragment length polymorphism and temperature gradient gel electrophoresis. The results allowed us to differentiate between alterations in the microbial community apparently caused by inoculation and by the rhizosphere effect and seasonal fluctuations induced by the alfalfa plants and by the environment. Only moderate inoculation-dependent effects could be detected, while the alfalfa plants appeared to have a much stronger influence on the microbial community.

  8. Identification of Sinorhizobium (Ensifer) medicae based on a specific genomic sequence unveiled by M13-PCR fingerprinting.

    Science.gov (United States)

    Dourado, Ana Catarina; Alves, Paula I L; Tenreiro, Tania; Ferreira, Eugénio M; Tenreiro, Rogério; Fareleira, Paula; Crespo, M Teresa Barreto

    2009-12-01

    A collection of nodule isolates from Medicago polymorpha obtained from southern and central Portugal was evaluated by M13-PCR fingerprinting and hierarchical cluster analysis. Several genomic clusters were obtained which, by 16S rRNA gene sequencing of selected representatives, were shown to be associated with particular taxonomic groups of rhizobia and other soil bacteria. The method provided a clear separation between rhizobia and co-isolated non-symbiotic soil contaminants. Ten M13-PCR groups were assigned to Sinorhizobium (Ensifer) medicae and included all isolates responsible for the formation of nitrogen-fixing nodules upon re-inoculation of M. polymorpha test-plants. In addition, enterobacterial repetitive intergenic consensus (ERIC)-PCR fingerprinting indicated a high genomic heterogeneity within the major M13- PCR clusters of S. medicae isolates. Based on nucleotide sequence data of an M13-PCR amplicon of ca. 1500 bp, observed only in S. medicae isolates and spanning locus Smed_3707 to Smed_3709 from the pSMED01 plasmid sequence of S. medicae WSM419 genome's sequence, a pair of PCR primers was designed and used for direct PCR amplification of a 1399-bp sequence within this fragment. Additional in silico and in vitro experiments, as well as phylogenetic analysis, confirmed the specificity of this primer combination and therefore the reliability of this approach in the prompt identification of S. medicae isolates and their distinction from other soil bacteria.

  9. Sinorhizobium meliloti 1021 loss-of-function deletion mutation in chvI and its phenotypic characteristics.

    Science.gov (United States)

    Wang, Chunxia; Kemp, Jocelyn; Da Fonseca, Isabel O; Equi, Raymie C; Sheng, Xiaoyan; Charles, Trevor C; Sobral, Bruno W S

    2010-02-01

    Bacterial two-component regulatory systems (TCS) are common components of complex regulatory networks and cascades. In Sinorhizobium meliloti, the TCS ExoS/ChvI controls exopolysaccharide succinoglycan production and flagellum biosynthesis. Although this system plays a crucial role in establishing the symbiosis between S. meliloti and its host plant, it is not well characterized. Attempts to generate complete loss-of-function mutations in either exoS or chvI in S. meliloti have been unsuccessful; thus, it was previously suggested that exoS or chvI are essential genes for bacterial cell growth. We constructed a chvI mutant by completely deleting the open reading frame encoding this gene. The mutant strain failed to grow on complex medium, exhibited lower tolerance to acidic condition, produced significantly less poly-3-hydroxybutyrate than the wild type, was hypermotile, and exhibited an altered lipopolysaccharide profile. In addition, this mutant was defective in symbiosis with Medicago truncatula and M. sativa (alfalfa), although it induced root hair deformation as efficiently as the wild type. Together, our results demonstrate that ChvI is intimately involved in regulatory networks involving the cell envelope and metabolism; however, its precise role within the regulatory network remains to be determined.

  10. Crystallization and preliminary crystallographic studies of an active-site mutant hydantoin racemase from Sinorhizobium meliloti CECT4114

    International Nuclear Information System (INIS)

    Martínez-Rodríguez, Sergio; González-Ramírez, Luis Antonio; Clemente-Jiménez, Josefa María; Rodríguez-Vico, Felipe; Las Heras-Vázquez, Francisco Javier; Gavira, Jose Antonio; García-Ruiz, Juan Ma.

    2007-01-01

    Crystals of an active-site mutated hydantoin racemase from S. meliloti have been obtained in the presence and absence of d,l-5-isopropyl-hydantoin and characterized by X-ray diffraction. A recombinant active-site mutant of hydantoin racemase (C76A) from Sinorhizobium meliloti CECT 4114 (SmeHyuA) has been crystallized in the presence and absence of the substrate d,l-5-isopropyl hydantoin. Crystals of the SmeHyuA mutant suitable for data collection and structure determination were grown using the counter-diffusion method. X-ray data were collected to resolutions of 2.17 and 1.85 Å for the free and bound enzymes, respectively. Both crystals belong to space group R3 and contain two molecules of SmeHyuA per asymmetric unit. The crystals of the free and complexed SmeHyuA have unit-cell parameters a = b = 85.43, c = 152.37 Å and a = b = 85.69, c = 154.38 Å, crystal volumes per protein weight (V M ) of 1.94 and 1.98 Å 3 Da −1 and solvent contents of 36.7 and 37.9%, respectively

  11. 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.

  12. Cloning-free genome engineering in Sinorhizobium meliloti advances applications of Cre/loxP site-specific recombination.

    Science.gov (United States)

    Döhlemann, Johannes; Brennecke, Meike; Becker, Anke

    2016-09-10

    The soil-dwelling α-proteobacterium Sinorhizobium meliloti serves as model for studies of symbiotic nitrogen fixation, a highly important process in sustainable agriculture. Here, we report advancements of the genetic toolbox accelerating genome editing in S. meliloti. The hsdMSR operon encodes a type-I restriction-modification (R-M) system. Transformation of S. meliloti is counteracted by the restriction endonuclease HsdR degrading DNA which lacks the appropriate methylation pattern. We provide a stable S. meliloti hsdR deletion mutant showing enhanced transformation with Escherichia coli-derived plasmid DNA and demonstrate that using an E. coli plasmid donor, expressing S. meliloti methyl transferase genes, is an alternative strategy of increasing the transformation efficiency of S. meliloti. Furthermore, we devise a novel cloning-free genome editing (CFGE) method for S. meliloti, Agrobacterium tumefaciens and Xanthomonas campestris, and demonstrate the applicability of this method for intricate applications of the Cre/lox recombination system in S. meliloti. An enhanced Cre/lox system, allowing for serial deletions of large genomic regions, was established. An assay of lox spacer mutants identified a set of lox sites mediating specific recombination. The availability of several non-promiscuous Cre recognition sites enables simultaneous specific Cre/lox recombination events. CFGE combined with Cre/lox recombination is put forward as powerful approach for targeted genome editing, involving serial steps of manipulation to expedite the genetic accessibility of S. meliloti as chassis. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Crystallization and preliminary crystallographic studies of an active-site mutant hydantoin racemase from Sinorhizobium meliloti CECT4114

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Rodríguez, Sergio [Department of Cellular and Molecular Interactions, Vrije Universiteit Brussel, 1050 Brussels (Belgium); Ultrastructure Laboratory, Vrije Universiteit Brussel, 1050 Brussels (Belgium); González-Ramírez, Luis Antonio [Laboratorio de Estudios Cristalográficos, IACT (CSIC-U. Granada), P. T. Ciencias de la Salud, Granada 18100 (Spain); Clemente-Jiménez, Josefa María; Rodríguez-Vico, Felipe; Las Heras-Vázquez, Francisco Javier [Departamento de Química Física, Bioquímica y Química Inorgánica, Área de Bioquímica y Biología Molecular, Edf. CITE I, Universidad de Almería (Spain); Gavira, Jose Antonio, E-mail: jgavira@ugr.es; García-Ruiz, Juan Ma. [Laboratorio de Estudios Cristalográficos, IACT (CSIC-U. Granada), P. T. Ciencias de la Salud, Granada 18100 (Spain); Department of Cellular and Molecular Interactions, Vrije Universiteit Brussel, 1050 Brussels (Belgium)

    2008-01-01

    Crystals of an active-site mutated hydantoin racemase from S. meliloti have been obtained in the presence and absence of d,l-5-isopropyl-hydantoin and characterized by X-ray diffraction. A recombinant active-site mutant of hydantoin racemase (C76A) from Sinorhizobium meliloti CECT 4114 (SmeHyuA) has been crystallized in the presence and absence of the substrate d,l-5-isopropyl hydantoin. Crystals of the SmeHyuA mutant suitable for data collection and structure determination were grown using the counter-diffusion method. X-ray data were collected to resolutions of 2.17 and 1.85 Å for the free and bound enzymes, respectively. Both crystals belong to space group R3 and contain two molecules of SmeHyuA per asymmetric unit. The crystals of the free and complexed SmeHyuA have unit-cell parameters a = b = 85.43, c = 152.37 Å and a = b = 85.69, c = 154.38 Å, crystal volumes per protein weight (V{sub M}) of 1.94 and 1.98 Å{sup 3} Da{sup −1} and solvent contents of 36.7 and 37.9%, respectively.

  14. 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.

  15. 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...

  16. 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

  17. 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.

  18. Three phylogenetic groups of nodA and nifH genes in Sinorhizobium and Mesorhizobium isolates from leguminous trees growing in Africa and Latin America.

    Science.gov (United States)

    Haukka, K; Lindström, K; Young, J P

    1998-02-01

    The diversity and phylogeny of nodA and nifH genes were studied by using 52 rhizobial isolates from Acacia senegal, Prosopis chilensis, and related leguminous trees growing in Africa and Latin America. All of the strains had similar host ranges and belonged to the genera Sinorhizobium and Mesorhizobium, as previously determined by 16S rRNA gene sequence analysis. The restriction patterns and a sequence analysis of the nodA and nifH genes divided the strains into the following three distinct groups: sinorhizobia from Africa, sinorhizobia from Latin America, and mesorhizobia from both regions. In a phylogenetic tree also containing previously published sequences, the nodA genes of our rhizobia formed a branch of their own, but within the branch no correlation between symbiotic genes and host trees was apparent. Within the large group of African sinorhizobia, similar symbiotic gene types were found in different chromosomal backgrounds, suggesting that transfer of symbiotic genes has occurred across species boundaries. Most strains had plasmids, and the presence of plasmid-borne nifH was demonstrated by hybridization for some examples. The nodA and nifH genes of Sinorhizobium teranga ORS1009T grouped with the nodA and nifH genes of the other African sinorhizobia, but Sinorhizobium saheli ORS609T had a totally different nodA sequence, although it was closely related based on the 16S rRNA gene and nifH data. This might be because this S. saheli strain was originally isolated from Sesbania sp., which belongs to a different cross-nodulation group than Acacia and Prosopis spp. The factors that appear to have influenced the evolution of rhizobial symbiotic genes vary in importance at different taxonomic levels.

  19. Three Phylogenetic Groups of nodA and nifH Genes in Sinorhizobium and Mesorhizobium Isolates from Leguminous Trees Growing in Africa and Latin America

    Science.gov (United States)

    Haukka, Kaisa; Lindström, Kristina; Young, J. Peter W.

    1998-01-01

    The diversity and phylogeny of nodA and nifH genes were studied by using 52 rhizobial isolates from Acacia senegal, Prosopis chilensis, and related leguminous trees growing in Africa and Latin America. All of the strains had similar host ranges and belonged to the genera Sinorhizobium and Mesorhizobium, as previously determined by 16S rRNA gene sequence analysis. The restriction patterns and a sequence analysis of the nodA and nifH genes divided the strains into the following three distinct groups: sinorhizobia from Africa, sinorhizobia from Latin America, and mesorhizobia from both regions. In a phylogenetic tree also containing previously published sequences, the nodA genes of our rhizobia formed a branch of their own, but within the branch no correlation between symbiotic genes and host trees was apparent. Within the large group of African sinorhizobia, similar symbiotic gene types were found in different chromosomal backgrounds, suggesting that transfer of symbiotic genes has occurred across species boundaries. Most strains had plasmids, and the presence of plasmid-borne nifH was demonstrated by hybridization for some examples. The nodA and nifH genes of Sinorhizobium teranga ORS1009T grouped with the nodA and nifH genes of the other African sinorhizobia, but Sinorhizobium saheli ORS609T had a totally different nodA sequence, although it was closely related based on the 16S rRNA gene and nifH data. This might be because this S. saheli strain was originally isolated from Sesbania sp., which belongs to a different cross-nodulation group than Acacia and Prosopis spp. The factors that appear to have influenced the evolution of rhizobial symbiotic genes vary in importance at different taxonomic levels. PMID:9464375

  20. Characterization of Sinorhizobium sp. LM21 Prophages and Virus-Encoded DNA Methyltransferases in the Light of Comparative Genomic Analyses of the Sinorhizobial Virome

    Directory of Open Access Journals (Sweden)

    Przemyslaw Decewicz

    2017-06-01

    Full Text Available The genus Sinorhizobium/Ensifer mostly groups nitrogen-fixing bacteria that create root or stem nodules on leguminous plants and transform atmospheric nitrogen into ammonia, which improves the productivity of the plants. Although these biotechnologically-important bacteria are commonly found in various soil environments, little is known about their phages. In this study, the genome of Sinorhizobium sp. LM21 isolated from a heavy-metal-contaminated copper mine in Poland was investigated for the presence of prophages and DNA methyltransferase-encoding genes. In addition to the previously identified temperate phage, ΦLM21, and the phage-plasmid, pLM21S1, the analysis revealed the presence of three prophage regions. Moreover, four novel phage-encoded DNA methyltransferase (MTase genes were identified and the enzymes were characterized. It was shown that two of the identified viral MTases methylated the same target sequence (GANTC as cell cycle-regulated methyltransferase (CcrM of the bacterial host strain, LM21. This discovery was recognized as an example of the evolutionary convergence between enzymes of sinorhizobial viruses and their host, which may play an important role in virus cycle. In the last part of the study, thorough comparative analyses of 31 sinorhizobial (prophages (including active sinorhizobial phages and novel putative prophages retrieved and manually re-annotated from Sinorhizobium spp. genomes were performed. The networking analysis revealed the presence of highly conserved proteins (e.g., holins and endolysins and a high diversity of viral integrases. The analysis also revealed a large number of viral DNA MTases, whose genes were frequently located within the predicted replication modules of analyzed prophages, which may suggest their important regulatory role. Summarizing, complex analysis of the phage protein similarity network enabled a new insight into overall sinorhizobial virome diversity.

  1. Identification and phylogenetic analysis of Dirofilaria ursi (Nematoda: Filarioidea) from Wisconsin black bears (Ursus americanus) and its Wolbachia endosymbiont.

    Science.gov (United States)

    Michalski, Michelle L; Bain, Odile; Fischer, Kerstin; Fischer, Peter U; Kumar, Sanjay; Foster, Jeremy M

    2010-04-01

    Dirofilaria ursi is a filarial nematode of American black bears (Ursus americanus Pallas, 1780) that is vectored by black flies (Simuliidae) in many parts of the United States. In northwestern Wisconsin, the prevalence of microfilaremic bears during the fall hunting season was 21% (n = 47). Unsheathed blood microfilariae from Wisconsin bears possess characters consistent with the original description of D. ursi, as do adult worms observed histologically and grossly. Immunohistochemistry was used to identify the Wolbachia endosymbiont in the hypodermis and lateral cords of an adult female D. ursi. Amplification of wsp, gatB, coxA, fbpA, and ftsZ bacterial sequences from parasite DNA confirmed the presence of Wolbachia, and molecular phylogenetic analysis of the Wolbachia ftsZ gene groups the endosymbiont with Wolbachia from D. immitis and D. repens. Phylogenetic analysis of D. ursi 5s rDNA sequence confirms the morphological observations grouping this parasite as a member of Dirofilaria, and within the Dirofilaria - Onchocerca clade of filarial nematodes. This is the first report of Wolbachia characterization and molecular phylogeny information for D. ursi.

  2. Antibiotic treatment leads to the elimination of Wolbachia endosymbionts and sterility in the diplodiploid collembolan Folsomia candida

    Directory of Open Access Journals (Sweden)

    Kingcombe Rachel

    2009-08-01

    Full Text Available Abstract Background Wolbachia is an extremely widespread bacterial endosymbiont of arthropods and nematodes that causes a variety of reproductive peculiarities. Parthenogenesis is one such peculiarity but it has been hypothesised that this phenomenon may be functionally restricted to organisms that employ haplodiploid sex determination. Using two antibiotics, tetracycline and rifampicin, we attempted to eliminate Wolbachia from the diplodiploid host Folsomia candida, a species of springtail which is a widely used study organism. Results Molecular assays confirmed that elimination of Wolbachia was successfully achieved through continuous exposure of populations (over two generations and several weeks to rifampicin administered as 2.7% dry weight of their yeast food source. The consequence of this elimination was total sterility of all individuals, despite the continuation of normal egg production. Conclusion Microbial endosymbionts play an obligatory role in the reproduction of their diplodiploid host, most likely one in which the parthenogenetic process is facilitated by Wolbachia. A hitherto unknown level of host-parasite interdependence is thus recorded.

  3. Blochmannia endosymbionts improve colony growth and immune defence in the ant Camponotus fellah

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    Depoix Delphine

    2009-02-01

    Full Text Available Abstract Background Microorganisms are a large and diverse form of life. Many of them live in association with large multicellular organisms, developing symbiotic relations with the host and some have even evolved to form obligate endosymbiosis 1. All Carpenter ants (genus Camponotus studied hitherto harbour primary endosymbiotic bacteria of the Blochmannia genus. The role of these bacteria in ant nutrition has been demonstrated 2 but the omnivorous diet of these ants lead us to hypothesize that the bacteria might provide additional advantages to their host. In this study, we establish links between Blochmannia, growth of starting new colonies and the host immune response. Results We manipulated the number of bacterial endosymbionts in incipient laboratory-reared colonies of Camponotus fellah by administrating doses of an antibiotic (Rifampin mixed in honey-solution. Efficiency of the treatment was estimated by quantitative polymerase chain reaction and Fluorescent in situ hybridization (FISH, using Blochmannia specific primers (qPCR and two fluorescent probes (one for all Eubacterial and other specific for Blochmannia. Very few or no bacteria could be detected in treated ants. Incipient Rifampin treated colonies had significantly lower numbers of brood and adult workers than control colonies. The immune response of ants from control and treated colonies was estimated by inserting nylon filaments in the gaster and removing it after 24 h. In the control colonies, the encapsulation response was positively correlated to the bacterial amount, while no correlation was observed in treated colonies. Indeed, antibiotic treatment increased the encapsulation response of the workers, probably due to stress conditions. Conclusion The increased growth rate observed in non-treated colonies confirms the importance of Blochmannia in this phase of colony development. This would provide an important selective advantage during colony founding, where the colonies

  4. Synthesis of silver nanoparticles by endosymbiont Pseudomonas fluorescens CA 417 and their bactericidal activity.

    Science.gov (United States)

    Syed, Baker; M N, Nagendra Prasad; B L, Dhananjaya; K, Mohan Kumar; S, Yallappa; S, Satish

    2016-12-01

    The present study emphasizes on biogenic synthesis of silver nanoparticles and their bactericidal activity against human and phytopathogens. Nanoparticle synthesis was performed using endosymbiont Pseudomonas fluorescens CA 417 inhabiting Coffea arabica L. Synthesized nanoparticles were characterized using hyphenated spectroscopic techniques such as UV-vis spectroscopy which revealed maximum absorption 425nm. Fourier transform infrared spectroscopy (FTIR) analysis revealed the possible functional groups mediating and stabilizing silver nanoparticles with predominant peaks occurring at 3346 corresponding to hydroxyl group, 1635 corresponding carbonyl group and 680 to aromatic group. X-ray diffraction (XRD) analysis revealed the Bragg's diffraction pattern with distinct peaks at 38° 44°, 64° and 78° revealing the face-centered cubic (fcc) metallic crystal corresponding to the (111), (200), (220) and (311) facets of the crystal planes at 2θ angle. The energy dispersive X-ray spectroscopy (EDS) analysis revealed presence of high intense absorption peak at 3keV is a typical characteristic of nano-crystalline silver which confirmed the presence of elemental silver. TEM analysis revealed the size of the nanoparticles to be in the range 5-50nm with polydisperse nature of synthesized nanoparticles bearing myriad shapes. The particle size determined by Dynamic light scattering (DLS) method revealed average size to be 20.66nm. The synthesized silver nanoparticles exhibited significant antibacterial activity against panel of test pathogens. The results showed Klebsiella pneumoniae (MTCC 7407) and Xanthomonas campestris to be more sensitive among the test human pathogen and phyto-pathogen respectively. The study also reports synergistic effect of silver nanoparticles in combination with kanamycin which displayed increased fold activity up to 58.3% against Klebsiella pneumoniae (MTCC 7407). The results of the present investigation are promising enough and attribute towards

  5. The roles of positive and negative selection in the molecular evolution of insect endosymbionts.

    Science.gov (United States)

    Fry, Adam J; Wernegreen, Jennifer J

    2005-08-01

    The evolutionary rate acceleration observed in most endosymbiotic bacteria may be explained by higher mutation rates, changes in selective pressure, and increased fixation of deleterious mutations by genetic drift. Here, we explore the forces influencing molecular evolution in Blochmannia, an obligate endosymbiont of Camponotus and related ant genera. Our goals were to compare rates of sequence evolution in Blochmannia with related bacteria, to explore variation in the strength and efficacy of negative (purifying) selection, and to evaluate the effect of positive selection. For six Blochmannia pairs, plus Buchnera and related enterobacteria, estimates of sequence divergence at four genes confirm faster rates of synonymous evolution in the ant mutualist. This conclusion is based on higher dS between Blochmannia lineages despite their more recent divergence. Likewise, generally higher dN in Blochmannia indicates faster rates of nonsynonymous substitution in this group. One exception is the groEL gene, for which lower dN and dN/dS compared to Buchnera indicate exceptionally strong negative selection in Blochmannia. In addition, we explored evidence for positive selection in Blochmannia using both site-and lineage-based maximum likelihood models. These approaches confirmed heterogeneity of dN/dS among codon sites and revealed significant variation in dN/dS across Blochmannia lineages for three genes. Lineage variation affected genes independently, with no evidence of parallel changes in dN/dS across genes along a given branch. Our data also reveal instances of dN/dS greater than one; however, we do not interpret these large dN/dS ratios as evidence for positive selection. In sum, while drift may contribute to an overall rate acceleration at nonsynonymous sites in Blochmannia, variable selective pressures best explain the apparent gene-specific changes in dN/dS across lineages of this ant mutualist. In the course of this study, we reanalyzed variation at Buchnera gro

  6. 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.

  7. Consumo de frutas, verduras e legumes por gestantes adolescentes

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    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.

  8. [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.

  9. Screening for bacterial DNA in the hard tick Hyalomma marginatum (Ixodidae from Socotra Island (Yemen: detection of Francisella-like endosymbiont

    Directory of Open Access Journals (Sweden)

    M. Montagna

    2012-12-01

    Full Text Available Thirty-four adult ticks collected from livestock on Socotra Island (Yemen were identified as Hyalomma marginatum using traditional morphological characteristics. Morphological identification was confirmed for all the collected specimens using a molecular approach targeting a fragment of the mitochondrial gene 12S rRNA. All the specimens were examined for the presence of tick-borne pathogens and the tick endosymbiont Candidatus Midichloria mitochondrii using polymerase chain reaction. Three specimens out of the 34 analyzed tested positive to the presence of Francisella spp. leading to the first detection of these bacteria in H. marginatum on Socotra Island. The phylogenetic analyses conducted on a 660 bp fragment of the ribosomal gene 16S rRNA of Francisella spp. (including F. philomiragia as outgroup, the four subspecies of F. tularensis and the Francisella-like endosymbiont of ticks confirm that the newly detected Francisella strains cluster into the Francisella-like endosymbionts of ticks. Interestingly, the detected Francisella-like endosymbiont, shows a different genotype to that previously isolated from H. marginatum collected in Bulgaria. No specimen was positive for the presence of Rickettsia spp., Coxiella burnetii, Borrelia burgdorferi or M. mitochondrii.

  10. Nuclearia pattersoni sp. n. (Filosea), a new species of amphizoic amoeba isolated from gills of roach (Rutilus rutilus), and its rickettsial endosymbiont

    Czech Academy of Sciences Publication Activity Database

    Dyková, Iva; Veverková, Marie; Fiala, Ivan; Macháčková, Blanka; Pecková, Hana

    2003-01-01

    Roč. 50, č. 3 (2003), s. 161-170 ISSN 0015-5683 R&D Projects: GA AV ČR IAA6022202 Institutional research plan: CEZ:AV0Z6022909; CEZ:MSM 123100003 Keywords : Filosea * Nuclearia pattersoni * rickettsial endosymbiont Subject RIV: EA - Cell Biology Impact factor: 0.469, year: 2003

  11. PhoU Allows Rapid Adaptation to High Phosphate Concentrations by Modulating PstSCAB Transport Rate in Sinorhizobium meliloti.

    Science.gov (United States)

    diCenzo, George C; Sharthiya, Harsh; Nanda, Anish; Zamani, Maryam; Finan, Turlough M

    2017-09-15

    Maintenance of cellular phosphate homeostasis is essential for cellular life. The PhoU protein has emerged as a key regulator of this process in bacteria, and it is suggested to modulate phosphate import by PstSCAB and control activation of the phosphate limitation response by the PhoR-PhoB two-component system. However, a proper understanding of PhoU has remained elusive due to numerous complications of mutating phoU , including loss of viability and the genetic instability of the mutants. Here, we developed two sets of strains of Sinorhizobium meliloti that overcame these limitations and allowed a more detailed and comprehensive analysis of the biological and molecular activities of PhoU. The data showed that phoU cannot be deleted in the presence of phosphate unless PstSCAB is inactivated also. However, phoU deletions were readily recovered in phosphate-free media, and characterization of these mutants revealed that addition of phosphate to the environment resulted in toxic levels of PstSCAB-mediated phosphate accumulation. Phosphate uptake experiments indicated that PhoU significantly decreased the PstSCAB transport rate specifically in phosphate-replete cells but not in phosphate-starved cells and that PhoU could rapidly respond to elevated environmental phosphate concentrations and decrease the PstSCAB transport rate. Site-directed mutagenesis results suggested that the ability of PhoU to respond to phosphate levels was independent of the conformation of the PstSCAB transporter. Additionally, PhoU-PhoU and PhoU-PhoR interactions were detected using a bacterial two-hybrid screen. We propose that PhoU modulates PstSCAB and PhoR-PhoB in response to local, internal fluctuations in phosphate concentrations resulting from PstSCAB-mediated phosphate import. IMPORTANCE Correct maintenance of cellular phosphate homeostasis is critical in all kingdoms of life and in bacteria involves the PhoU protein. This work provides novel insights into the role of the Sinorhizobium

  12. Regulation of Polyhydroxybutyrate Accumulation in Sinorhizobium meliloti by theTrans-Encoded Small RNA MmgR.

    Science.gov (United States)

    Lagares, Antonio; Ceizel Borella, Germán; Linne, Uwe; Becker, Anke; Valverde, Claudio

    2017-04-15

    Riboregulation has a major role in the fine-tuning of multiple bacterial processes. Among the RNA players, trans -encoded untranslated small RNAs (sRNAs) regulate complex metabolic networks by tuning expression from multiple target genes in response to numerous signals. In Sinorhizobium meliloti , over 400 sRNAs are expressed under different stimuli. The sRNA MmgR (standing for M akes m ore g ranules R egulator) has been of particular interest to us since its sequence and structure are highly conserved among the alphaproteobacteria and its expression is regulated by the amount and quality of the bacterium's available nitrogen source. In this work, we explored the biological role of MmgR in S. meliloti 2011 by characterizing the effect of a deletion of the internal conserved core of mmgR ( mmgR Δ33-51 ). This mutation resulted in larger amounts of polyhydroxybutyrate (PHB) distributed into more intracellular granules than are found in the wild-type strain. This phenotype was expressed upon cessation of balanced growth owing to nitrogen depletion in the presence of surplus carbon (i.e., at a carbon/nitrogen molar ratio greater than 10). The normal PHB accumulation was complemented with a wild-type mmgR copy but not with unrelated sRNA genes. Furthermore, the expression of mmgR limited PHB accumulation in the wild type, regardless of the magnitude of the C surplus. Quantitative proteomic profiling and quantitative reverse transcription-PCR (qRT-PCR) revealed that the absence of MmgR results in a posttranscriptional overexpression of both PHB phasin proteins (PhaP1 and PhaP2). Together, our results indicate that the widely conserved alphaproteobacterial MmgR sRNA fine-tunes the regulation of PHB storage in S. meliloti IMPORTANCE High-throughput RNA sequencing has recently uncovered an overwhelming number of trans -encoded small RNAs (sRNAs) in diverse prokaryotes. In the nitrogen-fixing alphaproteobacterial symbiont of alfalfa root nodules Sinorhizobium meliloti

  13. Nitrate reduction associated with respiration in Sinorhizobium meliloti 2011 is performed by a membrane-bound molybdoenzyme.

    Science.gov (United States)

    Ferroni, Felix M; Rivas, María G; Rizzi, Alberto C; Lucca, María E; Perotti, Nora I; Brondino, Carlos D

    2011-10-01

    The purification and biochemical characterization of the respiratory membrane-bound nitrate reductase from Sinorhizobium meliloti 2011 (Sm NR) is reported together with the optimal conditions for cell growth and enzyme production. The best biomass yield was obtained under aerobic conditions in a fed-batch system using Luria-Bertani medium with glucose as carbon source. The highest level of Sm NR production was achieved using microaerobic conditions with the medium supplemented with both nitrate and nitrite. Sm NR is a mononuclear Mo-protein belonging to the DMSO reductase family isolated as a heterodimeric enzyme containing two subunits of 118 and 45 kDa. Protein characterization by mass spectrometry showed homology with respiratory nitrate reductases. UV-Vis spectra of as-isolated and dithionite reduced Sm NR showed characteristic absorption bands of iron-sulfur and heme centers. Kinetic studies indicate that Sm NR follows a Michaelis-Menten mechanism (K (m) = 97 ± 11 μM, V = 9.4 ± 0.5 μM min(-1), and k (cat) = 12.1 ± 0.6 s(-1)) and is inhibited by azide, chlorate, and cyanide with mixed inhibition patterns. Physiological and kinetic studies indicate that molybdenum is essential for NR activity and that replacement of this metal for tungsten inhibits the enzyme. Although no narGHI gene cluster has been annotated in the genome of rhizobia, the biochemical characterization indicates that Sm NR is a Mo-containing NR enzyme with molecular organization similar to NarGHI.

  14. An ABC-Type Cobalt Transport System Is Essential for Growth of Sinorhizobium melilotiat Trace Metal Concentrations ▿ †

    Science.gov (United States)

    Cheng, Jiujun; Poduska, Branislava; Morton, Richard A.; Finan, Turlough M.

    2011-01-01

    We report expression and mutant phenotypes for a gene cluster in Sinorhizobium meliloti, designated cbtJKL, that has been shown to encode an ABC-type cobalt transport system. Transcription of cbtJKLinitiated 384 nucleotides upstream from the cbtJtranslation start codon, and the resulting 5′ region contained a putative B12riboswitch. Expression of the cbtJKLgenes appeared to be controlled by (cobalt-loaded) cobalamin interacting at the B12riboswitch, since (i) a putative B12riboswitch was located within this large upstream region, (ii) cbtJtranscription was repressed upon addition of cobalt or vitamin B12, and (iii) deletions in the B12riboswitch resulted in constitutive cbtJKLtranscription. Insertion mutants in cbtJKLfailed to grow in LB medium, and growth was restored through the addition of cobalt but not other metals. This growth phenotype appeared to be due to the chelation of cobalt present in LB, and cbtJKLmutants also failed to grow in minimal medium containing the chelating agent EDTA unless the medium was supplemented with additional or excess cobalt. In uptake experiments, 57Co2+accumulation was high in wild-type cells expressing the cbtJKLgenes, whereas wild-type cells in which cbtJKLexpression was repressed showed reduced accumulation. In cbtJKLmutant cells, 57Co2+accumulation was reduced relative to that of the wild type, and presumably, this residual cobalt transport occurred via an alternate ion uptake system(s) that is not specific to cobalt. In symbiosis, the alternate system(s) appeared to mediate cobalt transport into bacteroid cells, as low cbtJKLexpression was detected in bacteroids and cbtJKLmutants formed N2-fixing nodules on alfalfa. PMID:21725018

  15. Global mapping of transcription start sites and promoter motifs in the symbiotic α-proteobacterium Sinorhizobium meliloti 1021

    Science.gov (United States)

    2013-01-01

    Background Sinorhizobium meliloti is a soil-dwelling α-proteobacterium that possesses a large, tripartite genome and engages in a nitrogen fixing symbiosis with its plant hosts. Although much is known about this important model organism, global characterization of genetic regulatory circuits has been hampered by a lack of information about transcription and promoters. Results Using an RNAseq approach and RNA populations representing 16 different growth and stress conditions, we comprehensively mapped S. meliloti transcription start sites (TSS). Our work identified 17,001 TSS that we grouped into six categories based on the genomic context of their transcripts: mRNA (4,430 TSS assigned to 2,657 protein-coding genes), leaderless mRNAs (171), putative mRNAs (425), internal sense transcripts (7,650), antisense RNA (3,720), and trans-encoded sRNAs (605). We used this TSS information to identify transcription factor binding sites and putative promoter sequences recognized by seven of the 15 known S. meliloti σ factors σ70, σ54, σH1, σH2, σE1, σE2, and σE9). Altogether, we predicted 2,770 new promoter sequences, including 1,302 located upstream of protein coding genes and 722 located upstream of antisense RNA or trans-encoded sRNA genes. To validate promoter predictions for targets of the general stress response σ factor, RpoE2 (σE2), we identified rpoE2-dependent genes using microarrays and confirmed TSS for a subset of these by 5′ RACE mapping. Conclusions By identifying TSS and promoters on a global scale, our work provides a firm foundation for the continued study of S. meliloti gene expression with relation to gene organization, σ factors and other transcription factors, and regulatory RNAs. PMID:23497287

  16. Symbiotic Nitrogen Fixation in Alfalfa (Medicago Sativa L.) by Sinorhizobium Meliloti at Al-Qassim Regions, Saudi Arabia

    International Nuclear Information System (INIS)

    Al-Barakah, F. N.; Mridha, M. A. U.

    2016-01-01

    The nodulation status in alfalfa (Medicago sativa L.) plants by Sinorhizobium meliloti under Saudi field condition was assessed in some selected farms in four seasons for two years. In the present study, we also monitored the introduced S. meliloti strains activity under Saudi soil conditions. The samples were collected at regular seasonal intervals from the selected farms. The total number of nodules, morphology of the nodules and the effectiveness of N/sub 2/-fixation was assessed. In general, it was revealed that soils in the selected areas in Saudi Arabia have sufficient bacteria of the proper types to nodulate the alfalfa plants. These nodules are high in number, small in size and white in color. The nodules obtained from most of the selected farms are ineffective for nitrogen fixation. Inoculation of alfalfa seeds with imported S. meliloti strains failed to fix the atmospheric nitrogen sufficiently and also the growth improvement of alfalfa plants. There was a wide variation in the occurrence of number of nodules among the four seasons in two years. It was also observed that summer season severely affected the nodulation making it nearly zero. This low number of nodules exerts a very slow recovery of nodule formation in the next year. The introduced strains were always over competing with the native strains but they did not survive because of hot and dry summer. Nitrogenase activity of the nodules collected from both the inoculated and non-inoculated farms were always very low in all the collected samples, which indicates that the ability of fixing nitrogen by S. meliloti strains in alfalfa under Saudi soils conditions is very low. (author)

  17. Loss of malic enzymes leads to metabolic imbalance and altered levels of trehalose and putrescine in the bacterium Sinorhizobium meliloti.

    Science.gov (United States)

    Zhang, Ye; Smallbone, Laura Anne; diCenzo, George C; Morton, Richard; Finan, Turlough M

    2016-07-26

    Malic enzymes decarboxylate the tricarboxylic acid (TCA) cycle intermediate malate to the glycolytic end-product pyruvate and are well positioned to regulate metabolic flux in central carbon metabolism. Despite the wide distribution of these enzymes, their biological roles are unclear in part because the reaction catalyzed by these enzymes can be by-passed by other pathways. The N2-fixing alfalfa symbiont Sinorhizobium meliloti contains both a NAD(P)-malic enzyme (DME) and a separate NADP-malic enzyme (TME) and to help understand the role of these enzymes, we investigated growth, metabolomic, and transcriptional consequences resulting from loss of these enzymes in free-living cells. Loss of DME, TME, or both enzymes had no effect on growth with the glycolytic substrate, glucose. In contrast, the dme mutants, but not tme, grew slowly on the gluconeogenic substrate succinate and this slow growth was further reduced upon the addition of glucose. The dme mutant strains incubated with succinate accumulated trehalose and hexose sugar phosphates, secreted malate, and relative to wild-type, these cells had moderately increased transcription of genes involved in gluconeogenesis and pathways that divert metabolites away from the TCA cycle. While tme mutant cells grew at the same rate as wild-type on succinate, they accumulated the compatible solute putrescine. NAD(P)-malic enzyme (DME) of S. meliloti is required for efficient metabolism of succinate via the TCA cycle. In dme mutants utilizing succinate, malate accumulates and is excreted and these cells appear to increase metabolite flow via gluconeogenesis with a resulting increase in the levels of hexose-6-phosphates and trehalose. For cells utilizing succinate, TME activity alone appeared to be insufficient to produce the levels of pyruvate required for efficient TCA cycle metabolism. Putrescine was found to accumulate in tme cells growing with succinate, and whether this is related to altered levels of NADPH requires

  18. The RpiR-Like Repressor IolR Regulates Inositol Catabolism in Sinorhizobium meliloti▿†

    Science.gov (United States)

    Kohler, Petra R. A.; Choong, Ee-Leng; Rossbach, Silvia

    2011-01-01

    Sinorhizobium meliloti, the nitrogen-fixing symbiont of alfalfa, has the ability to catabolize myo-, scyllo-, and d-chiro-inositol. Functional inositol catabolism (iol) genes are required for growth on these inositol isomers, and they play a role during plant-bacterium interactions. The inositol catabolism genes comprise the chromosomally encoded iolA (mmsA) and the iolY(smc01163)RCDEB genes, as well as the idhA gene located on the pSymB plasmid. Reverse transcriptase assays showed that the iolYRCDEB genes are transcribed as one operon. The iol genes were weakly expressed without induction, but their expression was strongly induced by myo-inositol. The putative transcriptional regulator of the iol genes, IolR, belongs to the RpiR-like repressor family. Electrophoretic mobility shift assays demonstrated that IolR recognized a conserved palindromic sequence (5′-GGAA-N6-TTCC-3′) in the upstream regions of the idhA, iolY, iolR, and iolC genes. Complementation assays found IolR to be required for the repression of its own gene and for the downregulation of the idhA-encoded myo-inositol dehydrogenase activity in the presence and absence of inositol. Further expression studies indicated that the late pathway intermediate 2-keto-5-deoxy-d-gluconic acid 6-phosphate (KDGP) functions as the true inducer of the iol genes. The iolA (mmsA) gene encoding methylmalonate semialdehyde dehydrogenase was not regulated by IolR. The S. meliloti iolA (mmsA) gene product seems to be involved in more than only the inositol catabolic pathway, since it was also found to be essential for valine catabolism, supporting its more recent annotation as mmsA. PMID:21784930

  19. TRANSITION METAL TRANSPORT IN PLANTS AND ASSOCIATED ENDOSYMBIONTS: ARBUSCULAR MYCORRHIZAL FUNGI AND RHIZOBIA

    Directory of Open Access Journals (Sweden)

    Manuel González-Guerrero

    2016-07-01

    Full Text Available Transition metals such as iron, copper, zinc, or molybdenum, are essential nutrients for plants. These elements are involved in almost every biological process, including photosynthesis, tolerance to biotic and abiotic stress, or symbiotic nitrogen fixation. However, plants often grow in soils with limiting metallic oligonutrient bioavailability. Consequently, to ensure the proper metal levels, plants have developed a complex metal uptake and distribution system, that not only involves the plant itself, but also its associated microorganisms. These microorganisms can simply increase metal solubility in soils and making them more accessible to the host plant, as well as induce the plant metal deficiency response, or deliver directly transition elements to cortical cells. Other, instead of providing metals can act as metal sinks, such as endosymbiotic rhizobia in legume nodules that requires relatively large amounts to carry out nitrogen fixation. In this review, we propose to do an overview of metal transport mechanisms in the plant-microbe system, emphasizing the role of arbuscular mycorrhizal fungi and endosymbiotic rhizobia.

  20. 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...

  1. 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 ...

  2. 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 ...

  3. 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 ...

  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. 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. 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,

  9. 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.

  10. 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...

  11. 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

  12. 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

  13. 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.

  14. 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

  15. Molecular characterization of the pSinB plasmid of the arsenite oxidizing, metallotolerant Sinorhizobium sp. M14 - insight into the heavy metal resistome of sinorhizobial extrachromosomal replicons.

    Science.gov (United States)

    Romaniuk, Krzysztof; Dziewit, Lukasz; Decewicz, Przemyslaw; Mielnicki, Sebastian; Radlinska, Monika; Drewniak, Lukasz

    2017-01-01

    Sinorhizobium sp. M14 is an As(III)-oxidizing, psychrotolerant strain, capable of growth in the presence of extremely high concentrations of arsenic and many other heavy metals. Metallotolerant abilities of the M14 strain depend upon the presence of two extrachromosomal replicons: pSinA (∼ 109 kb) and pSinB (∼ 300 kb). The latter was subjected to complex analysis. The performed analysis demonstrated that the plasmid pSinB is a narrow-host-range repABC-type replicon, which is fully stabilized by the phd-vapC-like toxin-antitoxin stabilizing system. In silico analysis showed that among the phenotypic gene clusters of the plasmid pSinB, eight modules are potentially involved in heavy metals resistance (HMR). These modules carry genes encoding efflux pumps, permeases, transporters and copper oxidases, which provide resistance to arsenic, cadmium, cobalt, copper, iron, mercury, nickel, silver and zinc. The functional analysis revealed that the HMR modules are active and have an effect on the minimal inhibitory concentration (MIC) values observed for the heterological host cells. The phenotype was manifested by an increase or decrease of the MICs of heavy metals and it was strain specific. The analysis of distribution of the heavy metal resistance genes, i.e. resistome, in Sinorhizobium spp. plasmids, revealed that the HMR modules are common in these replicons. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. 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.

  17. 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)

  18. 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

  19. 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.

  20. 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/.

  1. 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)

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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...

  11. 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

  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. Modification of Insect and Arachnid Behaviours by Vertically Transmitted Endosymbionts: Infections as Drivers of Behavioural Change and Evolutionary Novelty

    Directory of Open Access Journals (Sweden)

    Sara L. Goodacre

    2012-02-01

    Full Text Available Vertically acquired, endosymbiotic bacteria such as those belonging to the Rickettsiales and the Mollicutes are known to influence the biology of their arthropod hosts in order to favour their own transmission. In this study we investigate the influence of such reproductive parasites on the behavior of their insects and arachnid hosts. We find that changes in host behavior that are associated with endosymbiont infections are not restricted to characteristics that are directly associated with reproduction. Other behavioural traits, such as those involved in intraspecific competition or in dispersal may also be affected. Such behavioural shifts are expected to influence the level of intraspecific variation and the rate at which adaptation can occur through their effects on effective population size and gene flow amongst populations. Symbionts may thus influence both levels of polymorphism within species and the rate at which diversification can occur.

  14. Analysis of Species, Subgroups, and Endosymbionts of Bemisia tabaci (Hemiptera: Aleyrodidae) From Southwestern Cotton Fields in Turkey.

    Science.gov (United States)

    Karut, Kamil; Mete Karaca, M; Döker, Ismail; Kazak, Cengiz

    2017-08-01

    Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the most important insect pests worldwide including Turkey. Although there are substantial data regarding species composition of Turkish B. tabaci populations, the situation is still not clear and further investigations are needed. Therefore, in this study, species and subgroups of B. tabaci collected from cotton fields in southwestern part of Turkey (Antalya, Aydın, Denizli, and Muğla) were determined using microsatellite analysis, AluI-based mtCOI polymerase chain reaction-random length polymorphism, and sequencing. Secondary endosymbionts were also determined using diagnostic species-specific PCR. Middle East Asia Minor 1 (MEAM1), Mediterranean (MED) Q1, and MED Q2 were the species and subgroups found in this study. The MED species (85.3%) were found to be more dominant than MEAM1. Species status of B. tabaci varied depending on the location. Although all samples collected from Aydın were found to be Q1, three species and subgroups were found in Muğla. Secondary endosymbionts varied according to species and subgroups. Arsenophonus was found only from Q2, while Hamiltonella was detected in MEAM1 and Q1. In addition, high Rickettsia and low Wolbachia infections were detected in MEAM1 and Q1 populations, respectively. In conclusion, for the first time, we report the presence and symbiotic communities of Q1 from Turkey. We also found that the symbiont complement of the Q1 is more congruent with Q1 from Greece than other regions of the world, which may have some interesting implications for movement of this invasive subgroup. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Relationship between water soluble carbohydrate content, aphid endosymbionts and clonal performance of Sitobion avenae on cocksfoot cultivars.

    Directory of Open Access Journals (Sweden)

    Hussein Alkhedir

    Full Text Available Aphids feed on plant phloem sap, rich in sugars but poor in essential amino acids. However, sugars cause osmotic regulation problems for aphids, which they overcome by hydrolysing the sugars in their gut and polymerising the hydrolysis products into oligosaccharides, excreted with honeydew. Aphids harbour primary bacterial endosymbionts, which supply them with essential amino acids necessary for survival. They also harbour secondary (facultative endosymbionts (sfS, some of which have a positive impact on life history traits, although it is not yet known whether they also play a role in providing effective tolerance to differing levels of water soluble carbohydrates (WSCs. We investigated the relationship between WSC content of cocksfoot cultivars and performance of clones of the English grain aphid Sitobion avenae F. We evaluated how clone genotype and their sfS modulate performance on these different cultivars. We therefore examined the performance of genetically defined clones of S. avenae, collected from different host plants, harbouring different sfS. The performance was tested on 10 Dactylis glomerata L. cultivars with varying WSC content. D. glomerata is known as a wild host plant for S. avenae and is also commercially planted. We found that high WSCs levels are responsible for the resistance of D. glomerata cultivars to specific S. avenae clones. The minimum level of WSCs conferring resistance to D. glomerata cultivars was 1.7% dw. Cultivars with a WSC content of 2.2% or higher were resistant to S. avenae and did not allow reproduction. Our results further indicate that sfS modulate to some extend host plant cultivar adaptation in S. avenae. This is the first study revealing the importance of WSCs for aphid performance. Cocksfoot cultivars with a high content of WSCs might be therefore considered for aphid control or used for resistance breeding in this and other grass species, including cereals.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Transcriptome Analysis of Polyhydroxybutyrate Cycle Mutants Reveals Discrete Loci Connecting Nitrogen Utilization and Carbon Storage in Sinorhizobium meliloti.

    Science.gov (United States)

    D'Alessio, Maya; Nordeste, Ricardo; Doxey, Andrew C; Charles, Trevor C

    2017-01-01

    Polyhydroxybutyrate (PHB) and glycogen polymers are produced by bacteria as carbon storage compounds under unbalanced growth conditions. To gain insights into the transcriptional mechanisms controlling carbon storage in Sinorhizobium meliloti , we investigated the global transcriptomic response to the genetic disruption of key genes in PHB synthesis and degradation and in glycogen synthesis. Under both nitrogen-limited and balanced growth conditions, transcriptomic analysis was performed with genetic mutants deficient in PHB synthesis ( phbA , phbB , phbAB , and phbC ), PHB degradation ( bdhA , phaZ , and acsA2 ), and glycogen synthesis ( glgA1 ). Three distinct genomic regions of the pSymA megaplasmid exhibited altered expression in the wild type and the PHB cycle mutants that was not seen in the glycogen synthesis mutant. An Fnr family transcriptional motif was identified in the upstream regions of a cluster of genes showing similar transcriptional patterns across the mutants. This motif was found at the highest density in the genomic regions with the strongest transcriptional effect, and the presence of this motif upstream of genes in these regions was significantly correlated with decreased transcript abundance. Analysis of the genes in the pSymA regions revealed that they contain a genomic overrepresentation of Fnr family transcription factor-encoding genes. We hypothesize that these loci, containing mostly nitrogen utilization, denitrification, and nitrogen fixation genes, are regulated in response to the intracellular carbon/nitrogen balance. These results indicate a transcriptional regulatory association between intracellular carbon levels (mediated through the functionality of the PHB cycle) and the expression of nitrogen metabolism genes. IMPORTANCE The ability of bacteria to store carbon and energy as intracellular polymers uncouples cell growth and replication from nutrient uptake and provides flexibility in the use of resources as they are available to

  1. Role of specific quorum-sensing signals in the regulation of exopolysaccharide II production within Sinorhizobium meliloti spreading colonies.

    Directory of Open Access Journals (Sweden)

    Mengsheng Gao

    Full Text Available BACKGROUND: Quorum sensing (QS in Sinorhizobium meliloti involves at least half a dozen different N-acyl homoserine lactone (AHL signals. These signals are produced by SinI, the sole AHL synthase in S. meliloti Rm8530. The sinI gene is regulated by two LuxR-type transcriptional regulators, SinR and ExpR. Mutations in sinI, sinR and expR abolish the production of exopolysaccharide II (EPS II. METHODOLOGY/PRINCIPAL FINDINGS: This study investigated a new type of coordinated surface spreading of Rm8530 that can be categorized as swarming. Motility assays on semi-solid surfaces revealed that both flagella and EPS II are required for this type of motility. The production of EPS II depends on AHLs produced by SinI. Of these AHLs, only C(16:1- and 3-oxo-C(16:1-homoserine lactones (HSLs stimulated swarming in an ExpR-dependent manner. These two AHLs induced the strongest response in the wggR reporter fusions. WggR is a positive regulator of the EPS II biosynthesis gene expression. The levels of the wggR activation correlated with the extent of swarming. Furthermore, swarming of S. meliloti required the presence of the high molecular weight (HMW fraction of EPS II. Within swarming colonies, a recombinase-based RIVET reporter in the wggR gene was resolved in 30% of the cells, indicating an enhanced regulation of EPS II production in the subpopulation of cells, which was sufficient to support swarming of the entire colony. CONCLUSIONS/SIGNIFICANCE: Swarming behavior of S. meliloti Rm8530 on semi-solid surfaces is found to be dependent on the functional QS regulatory cascades. Even though multiple AHL signals are produced by the bacterium, only two AHLs species, C(16:1- and 3-oxo-C(16:1-HSLs, affected swarming by up-regulating the expression of wggR. While EPS II is produced by Rm8530 as high and low molecular weight fractions, only the HMW EPS II facilitated initial stages of swarming, thus, suggesting a function for this polymer.

  2. 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)

  3. 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.

  4. 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.

  5. 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/.

  6. 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.

  7. 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

  8. 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...

  9. 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)....

  10. Genetic diversity of Wolbachia endosymbionts in Culex quinquefasciatus from Hawai`i, Midway Atoll, and Samoa

    Science.gov (United States)

    Atkinson, Carter T.; Watcher-Weatherwax, William; Lapointe, Dennis

    2016-01-01

    Incompatible insect techniques are potential methods for controlling Culex quinquefasciatus and avian disease transmission in Hawai‘i without the use of pesticides or genetically modified organisms. The approach is based on naturally occurring sperm-egg incompatibilities within the Culex pipiens complex that are controlled by different strains of the bacterial endosymbiont Wolbachia pipientis (wPip). Incompatibilities can be unidirectional (crosses between males infected with strain A and females infected with strain B are fertile, while reciprocal crosses are not) or bidirectional (reciprocal crosses between sexes with different wPip strains are infertile). The technique depends on release of sufficient numbers of male mosquitoes infected with an incompatible wPip strain to suppress mosquito populations and reduce transmission of introduced avian malaria (Plasmodium relictum) and Avipoxvirus in native forest bird habitats. Both diseases are difficult to manage using more traditional methods based on removal and treatment of larval habitats and coordination of multiple approaches may be needed to control this vector. We characterized the diversity of Wolbachia strains in C. quinquefasciatus from Hawai‘i, Kaua‘i, Midway Atoll, and American Samoa with a variety of genetic markers to identify compatibility groups and their distribution within and between islands. We confirmed the presence of wPip with multilocus sequence typing, tested for local genetic variability using 16 WO prophage genes, and identified similarities to strains from other parts of the world with a transposable element (tr1). We also tested for genetic differences in ankyrin motifs (ank2 and pk1) which have been used to classify wPip strains into five worldwide groups (wPip1–wPip5) that vary in compatibility with each other based on experimental crosses. We found a mixture of both widely distributed and site specific genotypes based on presence or absence of WO prophage and transposable

  11. Crystallization, preliminary X-ray diffraction and structure solution of MosA, a dihydrodipicolinate synthase from Sinorhizobium meliloti L5-30

    International Nuclear Information System (INIS)

    Leduc, Yvonne A.; Phenix, Christopher P.; Puttick, Jennifer; Nienaber, Kurt; Palmer, David R. J.; Delbaere, Louis T. J.

    2005-01-01

    MosA from S. meliloti L5-30 has been crystallized in solution with pyruvate and the 2.3 Å resolution structure has been solved by molecular replacement using E. coli dihydrodipicolinate synthase as the model. The structure of MosA, a dihydrodipicolinate synthase and reported methyltransferase from Sinorhizobium meliloti, has been solved using molecular replacement with Escherichia coli dihydrodipicolinate synthase as the model. A crystal grown in the presence of pyruvate diffracted X-rays to 2.3 Å resolution using synchrotron radiation and belonged to the orthorhombic space group C222 1 , with unit-cell parameters a = 69.14, b = 138.87, c = 124.13 Å

  12. The succinoglycan endoglycanase encoded by exoK is required for efficient symbiosis of Sinorhizobium meliloti 1021 with the host plants Medicago truncatula and Medicago sativa (Alfalfa).

    Science.gov (United States)

    Mendis, Hajeewaka C; Queiroux, Clothilde; Brewer, Tess E; Davis, Olivia M; Washburn, Brian K; Jones, Kathryn M

    2013-09-01

    The acidic polysaccharide succinoglycan produced by the nitrogen-fixing rhizobial symbiont Sinorhizobium meliloti 1021 is required for this bacterium to invade the host plant Medicago truncatula and to efficiently invade the host plant M. sativa (alfalfa). The β-glucanase enzyme encoded by exoK has previously been demonstrated to cleave succinoglycan and participate in producing the low molecular weight form of this polysaccharide. Here, we show that exoK is required for efficient S. meliloti invasion of both M. truncatula and alfalfa. Deletion mutants of exoK have a substantial reduction in symbiotic productivity on both of these plant hosts. Insertion mutants of exoK have an even less productive symbiosis than the deletion mutants with the host M. truncatula that is caused by a secondary effect of the insertion itself, and may be due to a polar effect on the expression of the downstream exoLAMON genes.

  13. The genome, proteome and phylogenetic analysis of Sinorhizobium meliloti phage ΦM12, the founder of a new group of T4-superfamily phages.

    Science.gov (United States)

    Brewer, Tess E; Stroupe, M Elizabeth; Jones, Kathryn M

    2014-02-01

    Phage ΦM12 is an important transducing phage of the nitrogen-fixing rhizobial bacterium Sinorhizobium meliloti. Here we report the genome, phylogenetic analysis, and proteome of ΦM12, the first report of the genome and proteome of a rhizobium-infecting T4-superfamily phage. The structural genes of ΦM12 are most similar to T4-superfamily phages of cyanobacteria. ΦM12 is the first reported T4-superfamily phage to lack genes encoding class I ribonucleotide reductase (RNR) and exonuclease dexA, and to possess a class II coenzyme B12-dependent RNR. ΦM12's novel collection of genes establishes it as the founder of a new group of T4-superfamily phages, fusing features of cyanophages and phages of enteric bacteria. © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Characterization of a partner switching system regulating c-di-GMP levels in Sinorhizobium meliloti. Implication in the synthesis of a novel exopolysaccharide

    OpenAIRE

    Baena Ropero, Irene

    2016-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 04-02-2016 Esta tesis tiene embargado el acceso al texto completo hasta el 04-08-2017 Sinorhizobium meliloti produce un β-D-glucano de enlaces alternos (1→3) (1→4) (ML β-glucano) en respuesta a altos niveles de diguanilato cíclico (di-GMP-c). Dos proteínas, BgsB y BgsA, son las responsables de la síntesis, siendo BgsA la glucano sintasa que sensa dichos ni...

  15. Intra-specific differentiation of fungal endosymbiont Alternaria longissima CLB44 using RNA secondary structure analysis and their anti-infective potential.

    Science.gov (United States)

    Rao, H C Yashavantha; Satish, Sreedharamurthy

    2016-08-01

    New antimicrobial agents derived from endosymbio-tic fungi with unique and targeted mode of action are crucially rudimentary to combat multidrug-resistant infections. Most of the fungi isolated as endosymbionts show close morphological feature resemblance to plant pathogenic or free-living forms, and it is difficult to differentiate these different lifestyles. A fungal endosymbiont strain CLB44 was isolated from Combretum latifolium Blume (Combretaceae). CLB44 was then identified as Alternaria longissima based on morphological and internal transcribed spacer (ITS) intervening 5.8S rRNA gene sequence analysis. ITS2 RNA secondary structure analysis was carried out using mfold server with temperature 37 °C, and anti-infective potential was determined by MIC and disk diffusion methods. ITS2 RNA secondary structure analysis clearly distinguished endosymbiotic A. longissima CLB44 from free-living and pathogenic A. longissima members in the same monophyletic clade. Secondary metabolites produced effectively inhibited Pseudomonas aeruginosa (25 μg/ml), Escherichia coli (25 μg/ml), methicillin-resistant Staphylococcus aureus (50 μg/ml), Candida albicans (100 μg/ml), and other human pathogens. This study emerges as an innovative finding that explores newly revealed ITS2 RNAs that may be an insight as new markers for refining phylogenetic relations and to distinguish fungal endosymbionts with other free-living or pathogenic forms. A. longissima CLB44, in the emerging field of endosymbionts, will pave the way to a novel avenue in drug discovery to combat multidrug-resistant infections. The sequence data of this fungus is deposited in GenBank under the accession no. KU310611.

  16. 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...

  17. GeMprospector--online design of cross-species genetic marker candidates in legumes and grasses.

    Science.gov (United States)

    Fredslund, Jakob; Madsen, Lene H; Hougaard, Birgit K; Sandal, Niels; Stougaard, Jens; Bertioli, David; Schauser, Leif

    2006-07-01

    The web program GeMprospector (URL: http://cgi-www.daimi.au.dk/cgi-chili/GeMprospector/main) allows users to automatically design large sets of cross-species genetic marker candidates targeting either legumes or grasses. The user uploads a collection of ESTs from one or more legume or grass species, and they are compared with a database of clusters of homologous EST and genomic sequences from other legumes or grasses, respectively. Multiple sequence alignments between submitted ESTs and their homologues in the appropriate database form the basis of automated PCR primer design in conserved exons such that each primer set amplifies an intron. The only user input is a collection of ESTs, not necessarily from more than one species, and GeMprospector can boost the potential of such an EST collection by combining it with a large database to produce cross-species genetic marker candidates for legumes or grasses.

  18. Potential Uses of Wild Germplasms of Grain Legumes for Crop Improvement.

    Science.gov (United States)

    Muñoz, Nacira; Liu, Ailin; Kan, Leo; Li, Man-Wah; Lam, Hon-Ming

    2017-02-04

    Challenged by population increase, climatic change, and soil deterioration, crop improvement is always a priority in securing food supplies. Although the production of grain legumes is in general lower than that of cereals, the nutritional value of grain legumes make them important components of food security. Nevertheless, limited by severe genetic bottlenecks during domestication and human selection, grain legumes, like other crops, have suffered from a loss of genetic diversity which is essential for providing genetic materials for crop improvement programs. Illustrated by whole-genome-sequencing, wild relatives of crops adapted to various environments were shown to maintain high genetic diversity. In this review, we focused on nine important grain legumes (soybean, peanut, pea, chickpea, common bean, lentil, cowpea, lupin, and pigeonpea) to discuss the potential uses of their wild relatives as genetic resources for crop breeding and improvement, and summarized the various genetic/genomic approaches adopted for these purposes.

  19. Phylogeny and Phylogeography of Rhizobial Symbionts Nodulating Legumes of the Tribe Genisteae

    Directory of Open Access Journals (Sweden)

    Tomasz Stępkowski

    2018-03-01

    Full Text Available The legume tribe Genisteae comprises 618, predominantly temperate species, showing an amphi-Atlantic distribution that was caused by several long-distance dispersal events. Seven out of the 16 authenticated rhizobial genera can nodulate particular Genisteae species. Bradyrhizobium predominates among rhizobia nodulating Genisteae legumes. Bradyrhizobium strains that infect Genisteae species belong to both the Bradyrhizobium japonicum and Bradyrhizobium elkanii superclades. In symbiotic gene phylogenies, Genisteae bradyrhizobia are scattered among several distinct clades, comprising strains that originate from phylogenetically distant legumes. This indicates that the capacity for nodulation of Genisteae spp. has evolved independently in various symbiotic gene clades, and that it has not been a long-multi-step process. The exception is Bradyrhizobium Clade II, which unlike other clades comprises strains that are specialized in nodulation of Genisteae, but also Loteae spp. Presumably, Clade II represents an example of long-lasting co-evolution of bradyrhizobial symbionts with their legume hosts.

  20. Deciphering composition and function of the root microbiome of a legume plant

    NARCIS (Netherlands)

    Hartman, Kyle; van der Heijden, Marcel G A; Roussely-Provent, Valexia; Walser, Jean-Claude; Schlaeppi, Klaus

    2017-01-01

    BACKGROUND: Diverse assemblages of microbes colonize plant roots and collectively function as a microbiome. Earlier work has characterized the root microbiomes of numerous plant species, but little information is available for legumes despite their key role in numerous ecosystems including

  1. Heating and Soaking Influence in Vitro Hindgut Fermentation of Tropical Legume Grains in Pigs.

    Science.gov (United States)

    Torres, Julieta; Muñoz, Luz S; Peters, Michael; Montoya, Carlos A

    2018-01-17

    The effects of different thermal (raw versus autoclaving or boiling for 5 and 20 min) and soaking (with or without) treatments on the in vitro hindgut fermentation in pigs of undigested residue collected after in vitro foregut digestion of tropical legumes' grains (Canavalia brasiliensis; Lablab purpureus; pink, red and white Vigna unguiculata) were investigated. The undigested residue was fermented with a pig fecal inoculum to determine fermentability, gas, and short-chain fatty acid (SCFA) productions. Soaked raw legumes increased the production of SCFAs (e.g., butyric acid) and fermentability, while autoclaving reduced them. The productions of butyric acid and energy derived from SCFAs differed between legumes, with canavalia and lablab having the lowest and highest values, respectively. SCFAs and energy productions were highly related to the predicted nutrients entering the hindgut. In conclusion, different heating and soaking treatments can be applied to legumes to modulate the production of target SCFAs.

  2. Ribosomal RNA analysis indicates a benthic pennate diatom ancestry for the endosymbionts of the dinoflagellates Peridinium foliaceum and Peridinium balticum (Pyrrhophyta).

    Science.gov (United States)

    Chesnick, J M; Kooistra, W H; Wellbrock, U; Medlin, L K

    1997-01-01

    The establishment of chloroplasts as cellular organelles in the dinoflagellate, heterokont (stramenopile), haptophyte, and cryptophyte algae is widely accepted to have been the result of secondary endosymbiotic events, that is, the uptake of a photosynthetic eukaryote by a phagotrophic eukaryote. However, the circumstances that promote such associations between two phylogenetically distinct organisms and result in the integration of their genomes to form a single functional photosynthetic cell is unclear. The dinoflagellates Peridinium foliaceum and Peridinium balticum are unusual in that each contains a membrane-bound eukaryotic heterokont endosymbiont. These symbioses have been interpreted, through data derived from ultrastructural and biochemical investigations, to represent an intermediate stage of secondary endosymbiotic chloroplast acquisition. In this study we have examined the phylogenetic origin of the P. foliaceum and P. balticum heterokont endosymbionts through analysis of their nuclear small subunit ribosomal RNA genes. Our analyses clearly demonstrate both endosymbionts are pennate diatoms belonging to the family Bacillariaceae. Since members of the Bacillariaceae are usually benthic, living on shallow marine sediments, the manner in which establishment of a symbiosis between a planktonic flagellated dinoflagellate and a bottom-dwelling diatom is discussed. In particular, specific environmentally-associated life strategy stages of the host and symbiont, coupled with diatom food preferences by the dinoflagellate, may have been vital to the formation of this association.

  3. Nutritional composition and in vitro digestibility of grass and legume winter (cover) crops.

    Science.gov (United States)

    Brown, A N; Ferreira, G; Teets, C L; Thomason, W E; Teutsch, C D

    2018-03-01

    In dairy farming systems, growing winter crops for forage is frequently limited to annual grasses grown in monoculture. The objectives of this study were to determine how cropping grasses alone or in mixtures with legumes affects the yield, nutritional composition, and in vitro digestibility of fresh and ensiled winter crops and the yield, nutritional composition, and in vitro digestibility of the subsequent summer crops. Experimental plots were planted with 15 different winter crops at 3 locations in Virginia. At each site, 4 plots of each treatment were planted in a randomized complete block design. The 15 treatments included 5 winter annual grasses [barley (BA), ryegrass (RG), rye (RY), triticale (TR), and wheat (WT)] in monoculture [i.e., no legumes (NO)] or with 1 of 2 winter annual legumes [crimson clover (CC) and hairy vetch (HV)]. After harvesting the winter crops, corn and forage sorghum were planted within the same plots perpendicular to the winter crop plantings. The nutritional composition and the in vitro digestibility of winter and summer crops were determined for fresh and ensiled samples. Growing grasses in mixtures with CC increased forage dry matter (DM) yield (2.84 Mg/ha), but the yield of mixtures with HV (2.47 Mg/ha) was similar to that of grasses grown in monoculture (2.40 Mg/ha). Growing grasses in mixtures with legumes increased the crude protein concentration of the fresh forage from 13.0% to 15.5% for CC and to 17.3% for HV. For neutral detergent fiber (NDF) concentrations, the interaction between grasses and legumes was significant for both fresh and ensiled forages. Growing BA, RY, and TR in mixtures with legumes decreased NDF concentrations, whereas growing RG and WT with legumes did not affect the NDF concentrations of either the fresh or the ensiled forages. Growing grasses in mixtures with legumes decreased the concentration of sugars of fresh forages relative to grasses grown in monoculture. Primarily, this decrease can be

  4. Contrasted nitrogen utilization in annual C 3 grass and legume crops: Physiological explorations and ecological considerations

    Science.gov (United States)

    Del Pozo, Alejandro; Garnier, Eric; Aronson, James

    2000-01-01

    Although it is well known that legumes have unusually high levels of nitrogen in both reproductive and vegetative organs, the physiological implications of this pattern have been poorly assessed. We conducted a literature survey and used data from two (unpublished) experiments on annual legumes and C 3 grasses in order to test whether these high nitrogen concentrations in legumes are correlated to high rates of carbon gain. Three different temporal/spatial scales were considered: full growing season/stand, days to month/whole plant and seconds/leaf. At the stand level, and for plants grown under both extratropical and tropical settings, biomass per unit organic-nitrogen was lower in legume than in grass crops. At a shorter time scale, the relative growth rate per unit plant nitrogen (`nitrogen productivity') was lower in faba bean ( Vicia faba var. minor cv. Tina) than in wheat ( Triticum aestivum cv. Alexandria), and this was confirmed in a comparison of two wild, circum-Mediterranean annuals - Medicago minima, a legume, and Bromus madritensis, a grass. Finally, at the leaf level, a synthesis of published data comparing soybean ( Glycine max) and rice ( Oryza sativa) on the one hand, and our own data on faba bean and wheat on the other hand, demonstrates that the photosynthetic rate per unit leaf nitrogen (the photosynthetic nitrogen use efficiency) is consistently lower in legumes than in grasses. These results demonstrate that, regardless of the scale considered and although the organic-nitrogen concentration in vegetative organs of legumes is higher than in grasses, this does not lead to higher rates of carbon gain in the former. Various physiological factors affecting the efficiency of nitrogen utilization at the three time scales considered are discussed. The suggestion is made that the ecological significance of the high nitrogen concentration in legumes may be related to a high nitrogen demand for high quality seed production at a time when nitrogen

  5. Legume breeding for rust resistance: Lessons to learn from the model Medicago truncatula

    OpenAIRE

    Rubiales, Diego; Castillejo Sánchez, M. Ángeles; Madrid, Eva; Barilli, Eleonora; Rispail, Nicolas

    2011-01-01

    Rusts are major biotic constraints of legumes worldwide. Breeding for rust resistance is regarded as the most cost efficient method for rust control. However, in contrast to common bean for which complete monogenic resistance exists and is efficiently used, most of the rust resistance reactions described so far in cool season food legumes are incomplete and of complex inheritance. Incomplete resistance has been described in faba bean, pea, chickpea and lentil and several of their associated Q...

  6. The Germination of Some Species Tropical Legume Seeds

    Directory of Open Access Journals (Sweden)

    Eko Poetri

    2005-09-01

    Full Text Available A study to evaluate the seed germination of Leucaena pallida under climatic and soil conditions in Palu was conducted in village of Taipa, Sub district of North Palu, District of Palu. To compare with other species of legume trees however, this study involved Leucaena leucocephala cv Tarramba, Leucaena leucocephala cv Gumph and Gliricidia maculata. This experiment used completely randomized design with species of tropical tree legumes as treatment.  Each treatment was replicated five times.  Each experimental unit consisted of one tray (size 12.5 x 25 cm and planted by 20 seed.  Each tray was filled with soil while the seeds were planted one cm deep.  All seeds were immersed in warm water (600C for five minutes before planted.  The base of the trays were drilled to create some holes for water to drain out.  The trays were sprayed twice daily (07.00 am and 03.00 pm to keep the soil to be moist using a very smooth sprayer.  The variables recorded included the initiation time of germination, the range time of germination and the percentage of seed germination.  The data obtained were analyses using the Minitab 11. Least significance difference was used to test for possible differences between treatment means. The result revealed that initiation time of germination and the range of germination were not varied (P>0.05 among the seeds tested. The initiation time of germination ranged between 9 to 12 d after sowing.  Gliricidia maculata seed has the shortest period to germinate (12-16 d after sowing, meanwhile Leucaena leucocephala cv. Tarramba appear to be the longest (9-17 d after sowing. The highest seed viability was 60% in Leucaena leucocephala, cv Gump while the lowest was found in Gliricidia maculata (29%. In addition, both Leucaena pallida and Leucaena leucocephala cv Tarramba had medium seed germination (40% and 53% respectively. (Animal Production 7(3: 156-160 (2005Key Words: Seed, Germination, Tropical Leguminous

  7. 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.

  8. Soil oribatid mite communities under three species of legumes in an ultisol in Brazil.

    Science.gov (United States)

    Badejo, M Adetola; Espindola, Jose Antonio Azevedo; Guerra, Jose Guilherme Marinho; De Aquino, Adriana Maria; Correa, Maria Elizabeth Fernandes

    2002-01-01

    Oribatid mite densities in the topsoil and their activity at the soil surface were monitored under three species of perennial legume cover crops namely, Arachis pintoi, Macroptilium atropupureum and Pueraria phaseoloides, grass (Panicum maximum) and bare plots on three occasions in 1998 and 1999 in a derived savanna zone in Brazil. Both densities and activity at the soil surface were higher in the early but cool dry season in April 1998 than in the early wet but warm season in November 1998 and 1999. Three taxonomic groups of macropyline oribatid mites, namely Nothrus, Archegozetes and Masthermannia as well as a brachypyline taxon, Scheloribates were suggested as possible indicators of effect of legumes on soil biota because their populations increased under the legumes and/or the irresidues. Nothrus in particular increased in abundance more than any other taxon in the presence of residues of A. pintoi. Each legume supported a unique oribatid mite community in terms of species composition and relative abundance. The large numbers of Archegozeres trapped from all the legume and grass plots in April and November 1998 were also attributed to highly conducive conditions provided by the vegetation cover and their residues. The results suggest that the oribatid mite community of the study area was numerically stable as the peak populations of different species were not synchronized. Many taxonomic groups of pycnonotic brachypyline mites were absent. Legume cover crops, especially A. pintoi, and their residues have potential in restoring oribatid mite populations to precultivation levels.

  9. Comprehensive comparative genomic and transcriptomic analyses of the legume genes controlling the nodulation process

    Directory of Open Access Journals (Sweden)

    Zhenzhen eQiao

    2016-01-01

    Full Text Available Nitrogen is one of the most essential plant nutrients and one of the major factors limiting crop productivity. Having the goal to perform a more sustainable agriculture, there is a need to maximize biological nitrogen fixation, a feature of legumes. To enhance our understanding of the molecular mechanisms controlling the interaction between legumes and rhizobia, the symbiotic partner fixing and assimilating the atmospheric nitrogen for the plant, researchers took advantage of genetic and genomic resources developed across different legume models (e.g. Medicago truncatula, Lotus japonicus, Glycine max and Phaseolous vulgaris to identify key regulatory genes of the nodulation process. In this study, we are presenting the results of a comprehensive comparative genomic analysis to highlight orthologous and paralogous relationships between the legume genes controlling nodulation. Mining large transcriptomic datasets, we also identified several orthologous and paralogous genes characterized by the induction of their expression during nodulation across legume plant species. This comprehensive study prompts new insights into the evolution of the nodulation process in legume plant and will benefit the scientific community interested in the transfer of functional genomic information between species.

  10. Physical, chemical and nutritional characteristics of premature-processed and matured green legumes.

    Science.gov (United States)

    Bhattacharya, Sila; Malleshi, N G

    2012-08-01

    Premature green legumes are good sources of nutraceuticals and antioxidants and are consumed as snacks as well as vegetables. They are seasonal and have limited shelf-life. Efforts are provided to prepare shelf-stable green legumes to extend their availability throughout the year. Green legumes from chick pea or Bengal gram (Cicer arietinum) and field bean (Dolichos lablab) have been processed to enhance their shelf-life, and determined their nutritional, physico-chemical and nutraceutical qualities. The shelf stable green legumes (SSGL) show higher water absorption capacity compared to matured dry legumes (MDL). The total colour change in the processed/dried SSGL and MDL samples increased significantly (p ≤ 0.05) compared to the freshly harvested green samples. The carotenoid content of Bengal gram and field bean SSGLs are 8.0 and 3.2 mg/100 g, and chlorophyll contents are 12.5 and 0.5 mg/100 g, respectively, which are in negligible quantities in matured legumes; the corresponding polyphenol contents are 197.8 and 153.1 mg/100 g. These results indicate that SSGLs possess potential antioxidant activity.

  11. Health benefits of legumes and pulses with a focus on Australian sweet lupins.

    Science.gov (United States)

    Kouris-Blazos, Antigone; Belski, Regina

    2016-01-01

    The 68th United Nations General Assembly declared 2016 the International Year of Pulses. Therefore it is timely to review the current evidence of the benefits of legumes for human health with a focus on Australian sweet lupins. Medline, Pubmed, Cochrane library were searched to identify cross-sectional/epidemiological studies, randomised controlled trials (RCTs) and systematic reviews. The strongest evidence appears to be for links between eating legumes and reduced risk of colorectal cancer as well as eating soy foods and reduced LDL cholesterol. However, epidemiological studies and RCTs suggest that replacing several meat-based meals a week with legumes can have a positive impact on longevity, diabetes, cardiovascular disease and weight management, potentially via favourable effects on the gut microbiome. Sweet lupins are unique among legumes with one of the highest combined amounts of digestible plant protein (38%) and dietary fibre (30%). Unlike other legumes, their low amount of anti-nutritional factors negates the need for soaking/cooking and they can therefore be eaten uncooked. Sweet lupins may lower blood pressure, improve blood lipids and insulin sensitivity and favourably alter the gut microbiome. There is growing interest in pulses, especially sweet lupins, as ingredients to improve the nutritional value of baked goods (particularly gluten free) and to create novel products to replace meat. Legumes form part of most traditional diets. They, including sweet lupins, can play a useful role in health maintenance.

  12. Legume intake and risk of prostate cancer: a meta-analysis of prospective cohort studies.

    Science.gov (United States)

    Li, Jie; Mao, Qi-Qi

    2017-07-04

    Previous studies regarding the relationship between legume intake and risk of prostate cancer have reported inconsistent results. We conducted a meta-analysis of prospective cohort studies to summarize evidence on this association. A systematic literature search of articles published through June 2016 was performed using PubMed and Web of Science databases. The combined relative risk (RR) with its 95% confidence interval (CI) for the highest versus the lowest intake of legumes was calculated with a random-effects model. Dose-response meta-analysis was also performed for the studies that provided at least three levels of legume consumption. Ten articles (eight cohorts) reporting 281,034 individuals and 10,234 incident cases were identified. The individuals with high consumption of legumes compared with the reference group experienced a significantly reduced risk for developing prostate cancer (RR: 0.85 [95% CI 0.75-0.96], P = 0.010). Moderate heterogeneity of RRs was observed across these studies (P = 0.064 for heterogeneity, I2 = 45.8 %). Dose-response meta-analysis indicated that the risk of prostate cancer reduced by 3.7% (95% CI 1.5%-5.8%) for each 20 grams per day increment of legume intake. In conclusion, the results from this meta-analysis suggest that a high intake of legumes is associated with a low incidence of prostate cancer.

  13. Secretion systems and signal exchange between nitrogen-fixing rhizobia and legumes.

    Science.gov (United States)

    Nelson, Matthew S; Sadowsky, Michael J

    2015-01-01

    The formation of symbiotic nitrogen-fixing nodules on the roots and/or stem of leguminous plants involves a complex signal exchange between both partners. Since many microorganisms are present in the soil, legumes and rhizobia must recognize and initiate communication with each other to establish symbioses. This results in the formation of nodules. Rhizobia within nodules exchange fixed nitrogen for carbon from the legume. Symbiotic relationships can become non-beneficial if one partner ceases to provide support to the other. As a result, complex signal exchange mechanisms have evolved to ensure continued, beneficial symbioses. Proper recognition and signal exchange is also the basis for host specificity. Nodule formation always provides a fitness benefit to rhizobia, but does not always provide a fitness benefit to legumes. Therefore, legumes have evolved a mechanism to regulate the number of nodules that are formed, this is called autoregulation of nodulation. Sequencing of many different rhizobia have revealed the presence of several secretion systems - and the Type III, Type IV, and Type VI secretion systems are known to be used by pathogens to transport effector proteins. These secretion systems are also known to have an effect on host specificity and are a determinant of overall nodule number on legumes. This review focuses on signal exchange between rhizobia and legumes, particularly focusing on the role of secretion systems involved in nodule formation and host specificity.

  14. Comprehensive Comparative Genomic and Transcriptomic Analyses of the Legume Genes Controlling the Nodulation Process.

    Science.gov (United States)

    Qiao, Zhenzhen; Pingault, Lise; Nourbakhsh-Rey, Mehrnoush; Libault, Marc

    2016-01-01

    Nitrogen is one of the most essential plant nutrients and one of the major factors limiting crop productivity. Having the goal to perform a more sustainable agriculture, there is a need to maximize biological nitrogen fixation, a feature of legumes. To enhance our understanding of the molecular mechanisms controlling the interaction between legumes and rhizobia, the symbiotic partner fixing and assimilating the atmospheric nitrogen for the plant, researchers took advantage of genetic and genomic resources developed across different legume models (e.g., Medicago truncatula, Lotus japonicus, Glycine max, and Phaseolus vulgaris) to identify key regulatory protein coding genes of the nodulation process. In this study, we are presenting the results of a comprehensive comparative genomic analysis to highlight orthologous and paralogous relationships between the legume genes controlling nodulation. Mining large transcriptomic datasets, we also identified several orthologous and paralogous genes characterized by the induction of their expression during nodulation across legume plant species. This comprehensive study prompts new insights into the evolution of the nodulation process in legume plant and will benefit the scientific community interested in the transfer of functional genomic information between species.

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

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    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.

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

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    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.

  17. Acylated flavonol glycosides from the forage legume, Onobrychis viciifolia (sainfoin).

    Science.gov (United States)

    Veitch, Nigel C; Regos, Ionela; Kite, Geoffrey C; Treutter, Dieter

    2011-04-01

    Ten acylated flavonol glycosides were isolated from aqueous acetone extracts of the aerial parts of the forage legume, Onobrychis viciifolia, and their structures determined using spectroscopic methods. Among these were eight previously unreported examples which comprised either feruloylated or sinapoylated derivatives of 3-O-di- and 3-O-triglycosides of kaempferol (3,5,7,4'-tetrahydroxyflavone) or quercetin (3,5,7,3',4'-pentahydroxyflavone). The diglycosides were acylated at the primary Glc residue of O-α-Rhap(1→6)-β-Glcp (rutinose), whereas the triglycosides were acylated at the terminal Rha residues of the branched trisaccharides, O-α-Rhap(1→2)[α-Rhap(1→6)]-β-Galp or O-α-Rhap(1→2)[α-Rhap(1→6)]-β-Glcp. Identification of the primary 3-O-linked hexose residues as either Gal or Glc was carried out by negative ion electrospray and serial MS, and cryoprobe NMR spectroscopy. Analysis of UV and MS spectra of the acylated flavonol glycosides provided additional diagnostic features relevant to direct characterisation of these compounds in hyphenated analyses. Quantitative analysis of the acylated flavonol glycosides present in different aerial parts of sainfoin revealed that the highest concentrations were in mature leaflets. Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Production and transcriptional regulation of proanthocyanidin biosynthesis in forage legumes.

    Science.gov (United States)

    Zhou, Meiliang; Wei, Li; Sun, Zhanmin; Gao, Lihua; Meng, Yu; Tang, Yixiong; Wu, Yanmin

    2015-05-01

    Proanthocyanidins (PA), also known as condensed tannins, contribute to important forage legumes traits including disease resistance and forage quality. PA in forage plants has both positive and negative effects on feed digestibility and animal performance. The analytical methods and their applicability in measuring the contents of PA in forage plants are essential to studies on their nutritional effects. In spite of important breakthroughs in our understanding of the PA biosynthesis, important questions still remain to be answered such as the PA polymerization and transport. Recent advances in the understanding of transcription factor-mediated gene regulation mechanisms in anthocyanin and PA biosynthetic pathway in model plants suggest new approaches for the metabolic engineering of PA in forage plants. The present review will attempt to present the state-of-the-art of research in these areas and provide an update on the production and metabolic engineering of PA in forage plants. We hope that this will contribute to a better understanding of the ways in which PA production to manipulate the content of PA for beneficial effects in forage plants.

  19. Seed protein improvement in cereals and grain legumes

    International Nuclear Information System (INIS)

    1979-01-01

    Based upon the recommendations of a panel of experts in 1968, the Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture established an international programme to improve the protein content and quality in seed crops of importance to developing countries. Reports of previous meetings held under this programme have been published by the IAEA. The meeting on Seed Protein Improvement in Cereals and Grain Legumes, held in September 1978, marked the formal end of the FAO/IAEA/GSF Co-ordinated Research Programme on Seed Protein Improvement. It reviewed the progress achieved. Volume I covers 27 papers. Following a review of the world protein and nutritional situation, the contributions are grouped under the main headings of the need for and use of variability in protein characteristics; genetics, biochemistry and physiology of seed storage proteins; analytical and nutritional techniques; and coordinated research programmes under a joint FAO/IAEA/GSF programme on grain protein improvement. Individual papers of direct relevance are cited as separate entries in INIS

  20. 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.

  1. Legumes increase rhizosphere carbon and nitrogen relative to cereals in California agricultural plots

    Science.gov (United States)

    Bergman, R.; Maltais-landry, G.

    2013-12-01

    Nitrogen (N) is an essential nutrient to plant growth, therefore a sufficient supply is needed for high yields. By using N-fixing plants like legumes in crop rotation, we can increase soil N and yields of following crops. Furthermore, legumes also affect soil carbon (C) and C:N ratios, which impacts nutrient cycling in soils. We assessed the effects of two legumes (vetch, fava bean) and a cereal mixture (oats and wheat) on soil N and C by comparing both rhizosphere and bulk soils. We studied the impacts of these plants with different management types (organic, low-input conventional, unfertilized) to see if plant effects on soil C and N changed across management. We used plots from the Long-Term Research on Agricultural Systems (LTRAS) experiment (Davis, CA) to conduct this experiment, where three plots were under each management type. Within each of these plots, we sampled three micro-plots, where we collected rhizosphere soil from fava bean, vetch, and cereals as well as bulk soil, i.e. non-rhizosphere soil. We collected 108 samples, each of which were dried and ball-milled into a fine, uniform powder. Tin capsules with 15-30mg of soil were then analyzed with a Carlo Erba Elemental analyzer to measure how much N and C was present in each of the samples. The different management types didn't affect the relationship among plants, but soil C and N were highest in organic and lowest in unfertilized plots. We found that N was significantly higher in legume rhizosphere than cereal rhizosphere and bulk soils. Soil C was also higher in legumes vs. cereals and bulk soils, but the only significant difference was with the bulk soils. This ultimately resulted in lower C:N ratios in the rhizosphere of legumes, only vetch, however, had significantly lower soil C:N than cereals. Vetch had higher N, and lower C and C:N than fava bean, but the difference between the two legumes was never significant. Similarly, cereals had higher C and N and lower C:N than bulk soils, although

  2. Generalist dinoflagellate endosymbionts and host genotype diversity detected from mesophotic (67-100 m depths coral Leptoseris

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    Kahng Samuel E

    2009-09-01

    Full Text Available Abstract Background Mesophotic corals (light-dependent corals in the deepest half of the photic zone at depths of 30 - 150 m provide a unique opportunity to study the limits of the interactions between corals and endosymbiotic dinoflagellates in the genus Symbiodinium. We sampled Leptoseris spp. in Hawaii via manned submersibles across a depth range of 67 - 100 m. Both the host and Symbiodinium communities were genotyped, using a non-coding region of the mitochondrial ND5 intron (NAD5 and the nuclear ribosomal internal transcribed spacer region 2 (ITS2, respectively. Results Coral colonies harbored endosymbiotic communities dominated by previously identified shallow water Symbiodinium ITS2 types (C1_ AF333515, C1c_ AY239364, C27_ AY239379, and C1b_ AY239363 and exhibited genetic variability at mitochondrial NAD5. Conclusion This is one of the first studies to examine genetic diversity in corals and their endosymbiotic dinoflagellates sampled at the limits of the depth and light gradients for hermatypic corals. The results reveal that these corals associate with generalist endosymbiont types commonly found in shallow water corals and implies that the composition of the Symbiodinium community (based on ITS2 alone is not responsible for the dominance and broad depth distribution of Leptoseris spp. The level of genetic diversity detected in the coral NAD5 suggests that there is undescribed taxonomic diversity in the genus Leptoseris from Hawaii.

  3. Purification and partial genome characterization of the bacterial endosymbiont Blattabacterium cuenoti from the fat bodies of cockroaches

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    Yamada Akinori

    2008-11-01

    Full Text Available Abstract Background Symbiotic relationships between intracellular bacteria and eukaryotes are widespread in nature. Genome sequencing of the bacterial partner has provided a number of key insights into the basis of these symbioses. A challenging aspect of sequencing symbiont genomes is separating the bacteria from the host tissues. In the present study, we describe a simple method of endosymbiont purification from complex environment, using Blattabacterium cuenoti inhabiting in cockroaches as a model system. Findings B. cuenoti cells were successfully purified from the fat bodies of the cockroach Panesthia angustipennis by a combination of slow- and fast-speed centrifugal fractionations, nylon-membrane filtration, and centrifugation with Percoll solutions. We performed pulse-field electrophoresis, diagnostic PCR and random sequencing of the shoutgun library. These experiments confirmed minimal contamination of host and mitochondrial DNA. The genome size and the G+C content of B. cuenoti were inferred to be 650 kb and 32.1 ± 7.6%, respectively. Conclusion The present study showed successful purification and characterization of the genome of B. cuenoti. Our methodology should be applicable for future symbiont genome sequencing projects. An advantage of the present purification method is that each step is easily performed with ordinary microtubes and a microcentrifuge, and without DNase treatment.

  4. The endosymbiont Wolbachia pipientis induces the expression of host antioxidant proteins in an Aedes albopictus cell line.

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    Lesley J Brennan

    Full Text Available Wolbachia are obligate intracellular bacteria which commonly infect arthropods. They are maternally inherited and capable of altering host development, sex determination, and reproduction. Reproductive manipulations include feminization, male-killing, parthenogenesis, and cytoplasmic incompatibility. The mechanism by which Wolbachia avoid destruction by the host immune response is unknown. Generation of antimicrobial peptides (AMPs and reactive oxygen species (ROS by the host are among the first lines of traditional antimicrobial defense. Previous work shows no link between a Wolbachia infection and the induction of AMPs. Here we compare the expression of protein in a cell line naturally infected with Wolbachia and an identical cell line cured of the infection through the use of antibiotics. Protein extracts of each cell line were analyzed by two dimensional gel electrophoresis and LC/MS/MS. Our results show the upregulation of host antioxidant proteins, which are active against ROS generated by aerobic cell metabolism and during an immune response. Furthermore, flow cytometric and microscopic analysis demonstrates that ROS production is significantly greater in Wolbachia-infected mosquito cells and is associated with endosymbiont-containing vacuoles located in the host cell cytoplasm. This is the first empirical data supporting an association between Wolbachia and the insect antioxidant system.

  5. Integration of molecular, ecological, morphological and endosymbiont data for species delimitation within the Pnigalio soemius complex (Hymenoptera: Eulophidae).

    Science.gov (United States)

    Gebiola, M; Gómez-Zurita, J; Monti, M M; Navone, P; Bernardo, U

    2012-03-01

    Integrative taxonomy is a recently developed approach that uses multiple lines of evidence such as molecular, morphological, ecological and geographical data to test species limits, and it stands as one of the most promising approaches to species delimitation in taxonomically difficult groups. The Pnigalio soemius complex (Hymenoptera: Eulophidae) represents an interesting taxonomical and ecological study case, as it is characterized by a lack of informative morphological characters, deep mitochondrial divergence, and is susceptible to infection by parthenogenesis-inducing Rickettsia. We tested the effectiveness of an integrative taxonomy approach in delimiting species within the P. soemius complex. We analysed two molecular markers (COI and ITS2) using different methods, performed multivariate analysis on morphometric data and exploited ecological data such as host-plant system associations, geographical separation, and the prevalence, type and effects of endosymbiont infection. The challenge of resolving different levels of resolution in the data was met by setting up a formal procedure of data integration within and between conflicting independent lines of evidence. An iterative corroboration process of multiple sources of data eventually indicated the existence of several cryptic species that can be treated as stable taxonomic hypotheses. Furthermore, the integrative approach confirmed a trend towards host specificity within the presumed polyphagous P. soemius and suggested that Rickettsia could have played a major role in the reproductive isolation and genetic diversification of at least two species. © 2012 Blackwell Publishing Ltd.

  6. Long-range dispersal and high-latitude environments influence the population structure of a "stress-tolerant" dinoflagellate endosymbiont.

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    D Tye Pettay

    Full Text Available The migration and dispersal of stress-tolerant symbiotic dinoflagellates (genus Symbiodinium may influence the response of symbiotic reef-building corals to a warming climate. We analyzed the genetic structure of the stress-tolerant endosymbiont, Symbiodinium glynni nomen nudum (ITS2 - D1, obtained from Pocillopora colonies that dominate eastern Pacific coral communities. Eleven microsatellite loci identified genotypically diverse populations with minimal genetic subdivision throughout the Eastern Tropical Pacific, encompassing 1000's of square kilometers from mainland Mexico to the Galapagos Islands. The lack of population differentiation over these distances corresponds with extensive regional host connectivity and indicates that Pocillopora larvae, which maternally inherit their symbionts, aid in the dispersal of this symbiont. In contrast to its host, however, subtropical populations of S. glynni in the Gulf of California (Sea of Cortez were strongly differentiated from populations in tropical eastern Pacific. Selection pressures related to large seasonal fluctuations in temperature and irradiance likely explain this abrupt genetic discontinuity. We infer that S. glynni genotypes harbored by host larvae arriving from more southern locations are rapidly replaced by genotypes adapted to more temperate environments. The strong population structure of S. glynni corresponds with fluctuating environmental conditions and suggests that these genetically diverse populations have the potential to evolve rapidly to changing environments and reveals the importance of environmental extremes in driving microbial eukaryote (e.g., plankton speciation in marine ecosystems.

  7. Vector transmission of a plant-pathogenic bacterium in the Arsenophonus clade sharing ecological traits with facultative insect endosymbionts.

    Science.gov (United States)

    Bressan, Alberto; Sémétey, Olivier; Arneodo, Joel; Lherminier, Jeannine; Boudon-Padieu, Elisabeth

    2009-11-01

    The planthopper Pentastiridius leporinus (Hemiptera: Cixiidae) is the major vector of a nonculturable plant-pathogenic gamma-3 proteobacterium associated with a disease of sugar beet called syndrome "basses richesses" (SBR). The bacterium, here called SBR bacterium, belongs to the Arsenophonous clade, which includes mostly insect-associated facultative symbionts. Assays using field-collected planthopper nymphs and adults were carried out to investigate the interaction of SBR bacterium with the insect vector and its transmission to sugar beet. Field-collected planthoppers showed a percentage of infection that averaged from 57% for early instar nymphs to near 100% for late instar nymphs and emerging adults. SBR bacterium was persistently transmitted by emerging adults. Root-feeding nymphs were able to inoculate SBR bacterium to sugar beet. The bacterium was transmitted vertically from infected parental females to their respective offspring with an average frequency of 30%. Real-time polymerase chain reaction assays on dissected planthopper internal organs revealed a high concentration of the bacterium within male and female reproductive organs and within female salivary glands. SBR-like bacteria were observed through transmission electron microscopy in the cytoplasm of different insect organs including ovaries, salivary glands, and guts with no evidence for cytological disorders. SBR bacterium seems to share common ecological traits of insect-transmitted plant pathogens and facultative insect endosymbionts suggesting it may have evolved primarily as an insect-associated bacterium.

  8. Generalist dinoflagellate endosymbionts and host genotype diversity detected from mesophotic (67-100 m depths) coral Leptoseris.

    Science.gov (United States)

    Chan, Yvonne L; Pochon, Xavier; Fisher, Marla A; Wagner, Daniel; Concepcion, Gregory T; Kahng, Samuel E; Toonen, Robert J; Gates, Ruth D

    2009-09-11

    Mesophotic corals (light-dependent corals in the deepest half of the photic zone at depths of 30-150 m) provide a unique opportunity to study the limits of the interactions between corals and endosymbiotic dinoflagellates in the genus Symbiodinium. We sampled Leptoseris spp. in Hawaii via manned submersibles across a depth range of 67-100 m. Both the host and Symbiodinium communities were genotyped, using a non-coding region of the mitochondrial ND5 intron (NAD5) and the nuclear ribosomal internal transcribed spacer region 2 (ITS2), respectively. Coral colonies harbored endosymbiotic communities dominated by previously identified shallow water Symbiodinium ITS2 types (C1_ AF333515, C1c_ AY239364, C27_ AY239379, and C1b_ AY239363) and exhibited genetic variability at mitochondrial NAD5. This is one of the first studies to examine genetic diversity in corals and their endosymbiotic dinoflagellates sampled at the limits of the depth and light gradients for hermatypic corals. The results reveal that these corals associate with generalist endosymbiont types commonly found in shallow water corals and implies that the composition of the Symbiodinium community (based on ITS2) alone is not responsible for the dominance and broad depth distribution of Leptoseris spp. The level of genetic diversity detected in the coral NAD5 suggests that there is undescribed taxonomic diversity in the genus Leptoseris from Hawaii.

  9. Influence of legume crops on content of organic carbon in sandy soil

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    Hajduk Edmund

    2015-06-01

    Full Text Available The paper presents the results of a 3-year field experiment designed to evaluate the content of organic carbon in brown soil (Haplic Cambisol Dystric developed from a light loamy sand under legumes cultivation. Experimental factors were: species of legume crop (colorful-blooming pea (Pisum sativum, chickling vetch (Lathyrus sativus, narrow-leafed lupin (Lupinus angustifolius, methods of legumes tillage (legumes in pure culture and in mixture with naked oats and mineral N fertilization (0, 30, 60, 90 kg N·ha−1. Cultivation of legumes on sandy soil did not result in an increase of organic carbon content in the soil after harvest as compared to the initial situation, i.e. 7.39 vs. 7.76 g·kg−1 dry matter (DM, on average, respectively. However, there was the beneficial effect of this group of plants on soil abundance in organic matter, the manifestation of which was higher content of organic carbon in soils after legume harvest as compared to soils with oats grown (7.21 g·kg−1 DM, on average. Among experimental crops, cultivation of pea exerted the most positive action to organic carbon content (7.58 g·kg−1, after harvest, on average, whereas narrow-leaved lupin had the least effect on organic carbon content (7.23 g·kg−1, on average. Pure culture and greater intensity of legume cultivation associated with the use of higher doses of mineral nitrogen caused less reduction in organic carbon content in soils after harvest.

  10. The Effect of Irradiation Treatment on the Non-Enzymatic Browning Reaction in Legume Seeds

    International Nuclear Information System (INIS)

    El-Niely, H.F.G.

    2013-01-01

    The present study was conducted to evaluate the effects of gamma irradiation treatment, at room temperature, on the non-enzymatic browning reaction (Millerd reaction products, MRPs) generated in soybeans, broad beans and dried peas seeds at dose levels of 10, 30 and 60 kGy and their effects on the chemical constituents, soluble protein, available lysine and in vitro protein digestibility. The formation of MRPs in the studied legumes was assayed by monitoring the formation of brown pigments (browning intensity) by spectrophotometric method. The results revealed that the chemical composition of irradiated legumes showed non-significant differences relative to the raw one. A dose dependent decrease in soluble proteins and available lysine in the three legumes were observed. The non-enzymatic browning reaction was significantly increased with increasing the radiation dose, which was proved by changes in browning index tests. At the same time, the in vitro protein digestibility was increased after irradiation up to 60 kGy. Irradiation of dried peas with 60 kGy produced higher browning index than the other legumes. A positive correlation was observed between the radiation dose and the browning index for soybeans (R2= 0.96), broad beans (R2 = 0.81) and dried peas (R2 = 0.97) which means that 96%, 81% and 97 of the variation in the incidence of non-enzymatic browning reaction in soybean, broad bean and dried peas, respectively, are due to the effect of irradiation treatments. The present study suggests that the formation of non-enzymatic browning reaction did not impair the nutritional quality of legumes, therefore, the process of irradiation was helpful in increasing the in vitro protein digestibility of studied legumes. These results clearly indicated that gamma irradiation processing at the studied doses can add valuable effects to the studied legumes

  11. RNA interference-based resistance against a legume mastrevirus

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    Mansoor Shahid

    2011-11-01

    Full Text Available Abstract Background RNA interference (RNAi is a homology-dependant gene silencing mechanism and has been widely used to engineer resistance in plants against RNA viruses. However, its usefulness in delivering resistance against plant DNA viruses belonging to family Geminiviridae is still being debated. Although the RNAi approach has been shown, using a transient assay, to be useful in countering monocotyledonous plant-infecting geminiviruses of the genus Mastrevirus, it has yet to be investigated as a means of delivering resistance to dicot-infecting mastreviruses. Chickpea chlorotic dwarf Pakistan virus (CpCDPKV is a legume-infecting mastrevirus that affects chickpea and other leguminous crops in Pakistan. Results Here a hairpin (hpRNAi construct containing sequences encompassing part of replication-associated protein gene, intergenic region and part of the movement protein gene of CpCDPKV under the control of the Cauliflower mosaic virus 35S promoter has been produced and stably transformed into Nicotiana benthamiana. Plants harboring the hairpin construct were challenged with CpCDPKV. All non-transgenic N. benthamiana plants developed symptoms of CpCDPKV infection within two weeks post-inoculation. In contrast, none of the inoculated transgenic plants showed symptoms of infection and no viral DNA could be detected by Southern hybridization. A real-time quantitative PCR analysis identified very low-level accumulation of viral DNA in the inoculated transgenic plants. Conclusions The results presented show that the RNAi-based resistance strategy is useful in protecting plants from a dicot-infecting mastrevirus. The very low levels of virus detected in plant tissue of transgenic plants distal to the inoculation site suggest that virus movement and/or viral replication was impaired leading to plants that showed no discernible signs of virus infection.

  12. IMPLEMENTATION OF DNA MARKERS TO IMPROVE BREEDING OF FORAGE LEGUMES

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    S. Grljušić

    2008-09-01

    Full Text Available 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 forage species involved in program and comparison of conventional and molecular marker efficiency in variability evaluation. RAPDs were used (i to estimate availability of alfalfa (Medicago sativa L. and Medicago falcata L. genetic variation and (ii to identify changes of red clover (Trifolium pratense L. variability after natural selection. SSRs were applied to evaluate diversity within and among field pea (Pisum sativum L. var. arvense and sativum groups/varieties. A total of 90 (alfalfa or 92 (red clover polymorphic bands was found by RAPDs. Total number of SSR alleles recorded was 118. The average Roger's distance per species/genus estimated was 0.29 (red clover, 0.33 (alfalfa and 0.51 (field pea. 2D PCo analysis of each species/genus separated materials into respective groups. A high degree of genetic variation within populations/varieties of each investigated species was found by AMOVA. The correspondence between pairs of matrices based on the morphological and molecular data was significant (p=0.95 only for red clover. RAPD and SSR data have given valuable information on genetic structure of materials and provided a description that determines heterogeneity. Further studies will be focused on identifying quantitative trait loci and marker assisted selection.

  13. Biochemical studies on weaning foods based legumes and carrots

    International Nuclear Information System (INIS)

    Nabag, Fatima Omer

    1997-01-01

    Attempts were made to utilize available food sources in formulation of weaning foods. Common legumes (chick pea and pigeon pea ) were used as protein source. While dehydrated carrots powder were used as a vitamin A source. Addition of 25% chick pea increased the protein content of the weaning foods to 16.7% and 14.4%,respectively ,while Cerelac and Riri gave protein content of 15.3% and 7.3%,respectively. In corporation of carrots at 10% level gave a vitamin A content of 564 RE/100 g material. Weaning food containing chick pea recorded higher preference among panelists and significantly better (p≤0.05)than samples containing pigeon pea. The bulk density of newly developed based formulae CP 3 , PP 3 (0.7 g/ml, 0.8 g/ml, respectively ) was higher than the market weaning food Cerelac and Riri (0.6 g/ml and 0.5 g/ml,respectively )The formula CP 3 recorded lower hot paste viscosity (3500 cp.) than both values obtained for Cerelac (4500 cp.) and Riri (extremely viscous). The lysine content of CP 3 (3.9 g/100 g protein) was higher than respective values in market foods and for better when calculated per weaning material (0.65 g/100 g material) compared to the other products (0.57; 0.28 g/100 material of Cerelac and Riri, respectively). Chick pea-based formula (CP 3 ) was also found to possess higher in vitro protein didestibility (95.2%) compared to Cerelac (94.2%) and Riri (88.5%). The calculated protein efficiency ratio (C-PER) of CP 3 (1.7) was higher than that of Riri (1.6) and lower than that of cerelac (2.7). (Author)

  14. Small RNA pathways and diversity in model legumes: lessons from genomics.

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    Pilar eBustos-Sanmamed

    2013-07-01

    Full Text Available Small non coding RNAs (smRNA participate in the regulation of development, cell differentiation, adaptation to environmental constraints and defense responses in plants. They negatively regulate gene expression by degrading specific mRNA targets, repressing their translation or modifying chromatin conformation through homologous interaction with target loci. MicroRNAs (miRNA and short-interfering RNAs (siRNA are generated from long double stranded RNA (dsRNA that are cleaved into 20- to 24-nucleotide dsRNAs by RNase III proteins called DICERs (DCL. One strand of the duplex is then loaded onto effective complexes containing different ARGONAUTE (AGO proteins. In this review, we explored smRNA diversity in model legumes and compiled available data from miRBAse, the miRNA database, and from 22 reports of smRNA deep sequencing or miRNA identification genome-wide in Medicago truncatula, Glycine max and Lotus japonicus. In addition to conserved miRNAs present in other plant species, 229, 179 and 35 novel miRNA families were identified respectively in these 3 legumes, among which several seems legume-specific. New potential functions of several miRNAs in the legume-specific nodulation process are discussed. Furthermore, a new category of siRNA, the phased siRNAs, which seems to mainly regulate disease-resistance genes, was recently discovered in legumes. Despite that the genome sequence of model legumes are not yet fully completed, further analysis was performed by database mining of gene families and protein characteristics of DCLs and AGOs in these genomes. Although most components of the smRNA pathways are conserved, identifiable homologs of key smRNA players from non-legumes could not yet be detected in M. truncatula available genomic and expressed sequence databases. In addition, an important gene diversification was observed in the three legumes. Functional significance of these variant isoforms may reflect peculiarities of smRNA biogenesis in

  15. Multiple use of legumes as green manure in rotation with corn and hay for milk production

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    Edwin Castro Rincón

    2016-01-01

    Full Text Available The dry tropical livestock systems go through dramatic decrease in milk production during the dry season. This can be mitigated by including legumes as green manure in forage crops as silage and hay to feed cows. Two experiments were conducted to evaluate 1 the contribution of legumes to milk production in cows supplemented with Canavalia brasiliensis as hay and 2 the effect of the removal of legume (5 levels between 0-100 % on corn production as forage. A direct relationship between the level of legume biomass removal and reduced maize yield (r = 0.85 was observed. When levels of removal of C. brasiliensis were below 50 %, the forage yield of corn was not affected (MS 11,283 kg ha-1 compared to non-removal treatment (12,601 kg MS ha-1(p > 0.05. At the time of corn harvest, the total nitrogen decreased (15-20 %; NO3 varied between 8 and 26 mg/kg, with lower levels contained in the removal of 75 to 100 %; and 15 % organic C increased with the removal of 0, 25 and 50 % legume. Regarding the second experiment, it was found that cows supplemented with hay C. brasiliensis, increased their milk production by 17 % with supplementation of 1.5 % LW/day. The compositional quality of milk did not change due to the treatment of hay supplementation of C. brasiliensis

  16. Nitrogen modulation of legume root architecture signalling pathways involves phytohormones and small regulatory molecules

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    Nadiatul Akmal Mohd-Radzman

    2013-10-01

    Full Text Available Nitrogen, particularly nitrate is an important yield determinant for crops. However, current agricultural practice with excessive fertilizer usage has detrimental effects on the environment. Therefore, legumes have been suggested as a sustainable alternative for replenishing soil nitrogen. Legumes can uniquely form nitrogen-fixing nodules through symbiotic interaction with specialized soil bacteria. Legumes possess a highly plastic root system which modulates its architecture according to the nitrogen availability in the soil. Understanding how legumes regulate root development in response to nitrogen availability is an important step to improving root architecture. The nitrogen-mediated root development pathway starts with sensing soil nitrogen level followed by subsequent signal transduction pathways involving phytohormones, microRNAs and regulatory peptides that collectively modulate the growth and shape of the root system. This review focuses on the current understanding of nitrogen-mediated legume root architecture including local and systemic regulations by different N-sources and the modulations by phytohormones and small regulatory molecules.

  17. Emerging Genomic Tools for Legume Breeding: Current Status and Future Prospects

    Science.gov (United States)

    Pandey, Manish K.; Roorkiwal, Manish; Singh, Vikas K.; Ramalingam, Abirami; Kudapa, Himabindu; Thudi, Mahendar; Chitikineni, Anu; Rathore, Abhishek; Varshney, Rajeev K.

    2016-01-01

    Legumes play a vital role in ensuring global nutritional food security and improving soil quality through nitrogen fixation. Accelerated higher genetic gains is required to meet the demand of ever increasing global population. In recent years, speedy developments have been witnessed in legume genomics due to advancements in next-generation sequencing (NGS) and high-throughput genotyping technologies. Reference genome sequences for many legume crops have been reported in the last 5 years. The availability of the draft genome sequences and re-sequencing of elite genotypes for several important legume crops have made it possible to identify structural variations at large scale. Availability of large-scale genomic resources and low-cost and high-throughput genotyping technologies are enhancing the efficiency and resolution of genetic mapping and marker-trait association studies. Most importantly, deployment of molecular breeding approaches has resulted in development of improved lines in some legume crops such as chickpea and groundnut. In order to support genomics-driven crop improvement at a fast pace, the deployment of breeder-friendly genomics and decision support tools seems appear to be critical in breeding programs in developing countries. This review provides an overview of emerging genomics and informatics tools/approaches that will be the key driving force for accelerating genomics-assisted breeding and ultimately ensuring nutritional and food security in developing countries. PMID:27199998

  18. The Concentration of Zn, Fe, Mn, Cu and Se in Fiber Fractions of Legumes in Indonesia

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    Evitayani

    2010-05-01

    Full Text Available This study was carried out to evaluate concentration of micro minerals (Zn, Fe, Mn, Cu and Se of forages and their distribution in fiber fraction (neutral detergent fiber/NDF and acid detergent fiber/ADF in West Sumatra during dry and rainy seasons. Four species of common legume namely Leucaena leucocephala, Centrocema pubescens, Calopogonium mucunoides and Acacia mangium were collected at native pasture during rainy and dry seasons. The results showed that micro minerals concentration of forages and their distribution in fiber fraction varied among species and season. In general, concentration of micro minerals was slightly higher in rainy season compared to dry season either in legumes forages. Data on legume forages showed that 75% of legumes were deficient in Zn and Mn, 62.5 % deficient in Cu and 50 % deficient in Se. There was no species of legume deficient in Fe. Distribution of micro minerals in NDF and ADF were also significantly affected by species and season and depends on the kinds of element measured. Generally, micro minerals were associated in fiber fractions and it yield much higher during dry season compared to rainy season. Iron (Fe and selenium (Se in forages were the highest elements associated in NDF and ADF, while the lowest was found in Copper (Cu. (Animal Production 12(2: 105-110 (2010Keywords: Seasons, forages, micro mineral distribution, fiber fraction

  19. Anti-inflammatory effects of phytochemicals from fruits, vegetables, and food legumes: A review.

    Science.gov (United States)

    Zhu, Fengmei; Du, Bin; Xu, Baojun

    2017-06-12

    Inflammation is the first biological response of the immune system to infection, injury or irritation. Evidence suggests that the anti-inflammatory effect is mediated through the regulation of various inflammatory cytokines, such as nitric oxide, interleukins, tumor necrosis factor alpha-α, interferon gamma-γ as well as noncytokine mediator, prostaglandin E 2 . Fruits, vegetables, and food legumes contain high levels of phytochemicals that show anti-inflammatory effect, but their mechanisms of actions have not been completely identified. The aim of this paper was to summarize the recent investigations and findings regarding in vitro and animal model studies on the anti-inflammatory effects of fruits, vegetables, and food legumes. Specific cytokines released for specific type of physiological event might shed some light on the specific use of each source of phytochemicals that can benefit to counter the inflammatory response. As natural modulators of proinflammatory gene expressions, phytochemical from fruits, vegetables, and food legumes could be incorporated into novel bioactive anti-inflammatory formulations of various nutraceuticals and pharmaceuticals. Finally, these phytochemicals are discussed as the natural promotion strategy for the improvement of human health status. The phenolics and triterpenoids in fruits and vegetables showed higher anti-inflammatory activity than other compounds. In food legumes, lectins and peptides had anti-inflammatory activity in most cases. However, there are lack of human study data on the anti-inflammatory activity of phytochemicals from fruits, vegetables, and food legumes.

  20. Effect of industrial dehydration on the soluble carbohydrates and dietary fiber fractions in legumes.

    Science.gov (United States)

    Martín-Cabrejas, María A; Aguilera, Yolanda; Benítez, Vanesa; Molla, Esperanza; López-Andréu, Francisco J; Esteban, Rosa M

    2006-10-04

    The effects of soaking, cooking, and industrial dehydration treatments on soluble carbohydrates, including raffinose family oligosaccharides (RFOs), and also on total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble (SDF) dietary fiber fractions were studied in legumes (lentil and chickpea). Ciceritol and stachyose were the main alpha-galactosides for chickpea and lentil, respectively. The processing involved a drastic reduction of soluble carbohydrates of these legumes, 85% in the case of lentil and 57% in the case of chickpea. The processed legume flours presented low residual levels of alpha-galactosides, which are advisable for people with digestive problems. Processing of legumes involved changes in dietary fiber fractions. A general increase of IDF (27-36%) due to the increase of glucose and Klason lignin was observed. However, a different behavior of SDF was exhibited during thermal dehydration, this fraction increasing in the case of chickpea (32%) and decreasing in the case of lentil (27%). This is probably caused by the different structures and compositions of the cell wall networks of the legumes.

  1. Perennial Grain Legume Domestication Phase I: Criteria for Candidate Species Selection

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    Brandon Schlautman

    2018-03-01

    Full Text Available Annual cereal and legume grain production is dependent on inorganic nitrogen (N and other fertilizers inputs to resupply nutrients lost as harvested grain, via soil erosion/runoff, and by other natural or anthropogenic causes. Temperate-adapted perennial grain legumes, though currently non-existent, might be uniquely situated as crop plants able to provide relief from reliance on synthetic nitrogen while supplying stable yields of highly nutritious seeds in low-input agricultural ecosystems. As such, perennial grain legume breeding and domestication programs are being initiated at The Land Institute (Salina, KS, USA and elsewhere. This review aims to facilitate the development of those programs by providing criteria for evaluating potential species and in choosing candidates most likely to be domesticated and adopted as herbaceous, perennial, temperate-adapted grain legumes. We outline specific morphological and ecophysiological traits that may influence each candidate’s agronomic potential, the quality of its seeds and the ecosystem services it can provide. Finally, we suggest that perennial grain legume breeders and domesticators should consider how a candidate’s reproductive biology, genome structure and availability of genetic resources will determine its ease of breeding and its domestication timeline.

  2. Inoculation and inter-cropping of legumes in established grass for increasing biomass of fodder

    International Nuclear Information System (INIS)

    Ullah, M.A.; Hussain, N.

    2014-01-01

    Livestock sector has become very important component of agriculture sector in the world due to variety of dairy and meat products and high income to the farmers. In Pakistan, this vast resource faces many crucial challenges like low quality and high priced feed and fodder and limited chances of increasing area under fodders due to competition for food crops. Intercropping (33%, 50% and 67%) of Panicum maximum grass and legumes (Vicia sativa and cowpeas) coupled with inoculation was studied under rainfed conditions at National Agricultural Research Centre (NARC) Islamabad, Pakistan. Intercropping significantly increased tillering of grass. Seed inoculation of legumes also gave maximum tillers. The grass and legumes biomass without any treatment were recorded as 7.09 and -18.17 t ha, respectively, during two years of study. Mixed fodder -1 production increased to 11.62, 13.6 and 14.13 t ha with 33%, 50% and 67% intercropping, respectively. Respective values of biomass were -1 observed as 13.18, 13.70 and 17.87 t ha when combined with inoculation. Intercropping of grass and legumes 67% with inoculation was assessed as the best treatment. The increases were computed as 304%, 230%, 132%, and 60% over grass alone in the first, second, third and fourth crops while respective increases were 101%, 151%, 165% and 74% over monoculture legumes. (author)

  3. Flowers of the early-branching papilionoid legume Petaladenium urceoliferum display unique morphological and ontogenetic features.

    Science.gov (United States)

    Prenner, Gerhard; Cardoso, Domingos; Zartman, Charles E; de Queiroz, Luciano P

    2015-11-01

    Floral development can help to shed light on puzzling features across flowering plants. The enigmatic Amazonian monospecific genus Petaladenium of the legume family (Leguminosae) had rarely been collected and only recently became available for ontogenetic studies. The fimbriate-glandular wing petals of P. urceoliferum are unique among the more than 19000 legume species. Ontogenetic data illuminate the systematic position of the genus and foster our understanding on floral evolution during the early diversification of the papilionoid legumes. Flower buds were collected in the field, fixed in 70% ethanol, and investigated using scanning electron microscopy (SEM). Results were compared with existing material from early-diverging papilionoid legumes. Formation of sepals and petals shows bidirectional tendencies. Stamens arise in two whorls, and the single carpel arises concomitantly with the outer stamen whorl. Gland formation starts early on the edges of the wing petals. The carpel reopens for a short time when the initiation of ovules is visible. Stomata at the base of the hypanthium indicate that the flower functions like other standard flag blossoms. The floral ontogeny confirms the close affinity of P. urceoliferum with the florally heterogeneous, early-diverging papilionoid Amburaneae clade. The results strengthen the theory of a distinct experimental phase among early-branching papilionoid legumes during which a wider range of floral morphologies arose. Polysymmetry, monosymmetry, variable organ numbers, and a wide range of ontogenetic patterns laid the foundation for a successful canalization toward the more restricted but well-adapted dorsiventral papilionoid flag blossom. © 2015 Botanical Society of America.

  4. Comparative study on antioxidant activity of different varieties of commonly consumed legumes in India.

    Science.gov (United States)

    Marathe, Sushama A; Rajalakshmi, V; Jamdar, Sahayog N; Sharma, Arun

    2011-09-01

    Legumes are rich source of proteins, dietary fiber, micronutrients and bioactive phytochemicals. Thirty different varieties of commonly consumed legumes in India, were screened for phenolic content and antioxidant activity using, radical scavenging [(1,1-diphenyl-2-picryl-hydrazyl (DPPH·) and 2,2'-azino-bis (3-ethylbenz-thiazoline-6-sulfonic acid, (ABTS·⁺], Ferric Reducing Antioxidant Power (FRAP) and metal ion (Fe²⁺) chelation assays. Legumes varied largely in their antioxidant activity. Horse gram, common beans, cowpea (brown and red) and fenugreek showed high DPPH· radical scavenging activity (>400 units/g), while lablab bean (cream and white), chickpea (cream and green), butter bean and pea (white and green) showed low antioxidant activity (pea, lentils, cowpea (white) and common bean (maroon) showed intermediate activity. Similar trend was observed when the activity was assessed with ABTS·⁺ and FRAP assays. Thus most of the varieties having light color seed coat, except soybean exhibited low antioxidant activity. While legumes having dark color seed coat did not always possessed high antioxidant activity (e.g. moth bean, black pea, black gram, lentils). Antioxidant activity showed positive correlation (r²>0.95) with phenolic contents, in DPPH·, ABTS·⁺ and FRAP assays, whereas poor correlation (r²=0.297) was observed between Fe²⁺ chelating activity of the legumes and phenolic contents. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Estimation of Nitrogenase Enzyme Activities and Plant Growth of Legume and Non-legume Inoculated with Diazotrophic Bacteria

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    Salwani S.

    2012-06-01

    Full Text Available Biological Nitrogen Fixation (BNF process benefits the agriculture sector especially for reducing cost of nitrogenfertilizer. In the process, the diazotrophs convert N2 into ammonia (NH3 which is useable by plants. The BNF process iscatalysed by nitrogenase enzyme that involved protons and electrons together with evolution of H2 therefore, theassessment of N2 fixation is also available via H2 production and electron allocation analysis. Thus, the aims of thisexperiment were to estimate the nitrogenase enzyme activities and observe the influence of diazothrophs on growth oflegume (soybean and non legume (rice plants. Host plants were inoculated with respective inocula; Bradyrhizobiumjaponicum (strain 532C for soybean while Azospirillum brasilense (Sp7 and locally isolated diazotroph (isolate 5 forrice. At harvest, the plants were observed for plant growth parameters, H2 evolution, N2 fixation and electron allocationcoefficient (EAC values. The experiment recorded N2 fixation activities of inoculated soybean plants at 141.2 μmol N2 h-1g-1 dry weight nodule, and the evolution of H2 at 144.4 μmol H2 h-1 g-1 dry weight nodule. The electron allocationcoefficient (EAC of soybean was recorded at 0.982. For inoculated rice plants, none of the observations was successfully recorded. However, results for chlorophyll contents and plant dry weight of both plants inoculated with respective inocula were similar to the control treatments supplied with full nitrogen fertilization (+N. The experiment clearly showed that inoculation of diazotrophic bacteria could enhance growth of the host plants similar to plants treated with nitrogenous fertilizer due to efficient N2 fixation process

  6. Two-component regulatory system ActS/ActR is required for Sinorhizobium meliloti adaptation to oxidative stress.

    Science.gov (United States)

    Tang, Guirong; Wang, Sunjun; Lu, Dawei; Huang, Leqi; Li, Ningning; Luo, Li

    2017-05-01

    The two-component system ActS/ActR plays important roles in bacterial adaptation to abiotic stress, including acid tolerance and oxidant resistance. However, the underlying regulatory mechanism is not clear. In this study, we found that the ActS/ActR system is required for adaptation to oxidative stress by regulating the transcription of the genes actR, katB, gshA and gshB1. The actS and actR mutants were sensitive to low pH and oxidants such as H 2 O 2 , oxidized glutathione (GSSG) and sodium nitroprusside (SNP). The expression of actR by using a plasmid rescued the defect of SNP sensitivity for all actS and actR mutants. The expression of actS and actR were suppressed by treatment with H 2 O 2 . The expression of actS, actR, oxyR, katA and katB was required for ActS and ActR under normal conditions. The induction of katB, gshA and gshB1 depended on ActS and ActR during treatment with H 2 O 2 and SNP. Our findings revealed that the ActS/ActR system is a key redox regulator in S. meliltoi and provides a new cue to understanding Rhizobium-legume symbiosis. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  7. Effects of a sex-ratio distorting endosymbiont on mtDNA variation in a global insect pest

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    Cook James M

    2009-03-01

    Full Text Available Abstract Background Patterns of mtDNA variation within a species reflect long-term population structure, but may also be influenced by maternally inherited endosymbionts, such as Wolbachia. These bacteria often alter host reproductive biology and can drive particular mtDNA haplotypes through populations. We investigated the impacts of Wolbachia infection and geography on mtDNA variation in the diamondback moth, a major global pest whose geographic distribution reflects both natural processes and transport via human agricultural activities. Results The mtDNA phylogeny of 95 individuals sampled from 10 countries on four continents revealed two major clades. One contained only Wolbachia-infected individuals from Malaysia and Kenya, while the other contained only uninfected individuals, from all countries including Malaysia and Kenya. Within the uninfected group was a further clade containing all individuals from Australasia and displaying very limited sequence variation. In contrast, a biparental nuclear gene phylogeny did not have infected and uninfected clades, supporting the notion that maternally-inherited Wolbachia are responsible for the mtDNA pattern. Only about 5% (15/306 of our global sample of individuals was infected with the plutWB1 isolate and even within infected local populations, many insects were uninfected. Comparisons of infected and uninfected isofemale lines revealed that plutWB1 is associated with sex ratio distortion. Uninfected lines have a 1:1 sex ratio, while infected ones show a 2:1 female bias. Conclusion The main correlate of mtDNA variation in P. xylostella is presence or absence of the plutWB1 infection. This is associated with substantial sex ratio distortion and the underlying mechanisms deserve further study. In contrast, geographic origin is a poor predictor of moth mtDNA sequences, reflecting human activity in moving the insects around the globe. The exception is a clade of Australasian individuals, which may

  8. A community change in the algal endosymbionts of a scleractinian coral following a natural bleaching event: field evidence of acclimatization.

    Science.gov (United States)

    Jones, A M; Berkelmans, R; van Oppen, M J H; Mieog, J C; Sinclair, W

    2008-06-22

    The symbiosis between reef-building corals and their algal endosymbionts (zooxanthellae of the genus Symbiodinium) is highly sensitive to temperature stress, which makes coral reefs vulnerable to climate change. Thermal tolerance in corals is known to be substantially linked to the type of zooxanthellae they harbour and, when multiple types are present, the relative abundance of types can be experimentally manipulated to increase the thermal limits of individual corals. Although the potential exists for this to translate into substantial thermal acclimatization of coral communities, to date there is no evidence to show that this takes place under natural conditions. In this study, we show field evidence of a dramatic change in the symbiont community of Acropora millepora, a common and widespread Indo-Pacific hard coral species, after a natural bleaching event in early 2006 in the Keppel Islands (Great Barrier Reef). Before bleaching, 93.5% (n=460) of the randomly sampled and tagged colonies predominantly harboured the thermally sensitive Symbiodinium type C2, while the remainder harboured a tolerant Symbiodinium type belonging to clade D or mixtures of C2 and D. After bleaching, 71% of the surviving tagged colonies that were initially C2 predominant changed to D or C1 predominance. Colonies that were originally C2 predominant suffered high mortality (37%) compared with D-predominant colonies (8%). We estimate that just over 18% of the original A. millepora population survived unchanged leaving 29% of the population C2 and 71% D or C1 predominant six months after the bleaching event. This change in the symbiont community structure, while it persists, is likely to have substantially increased the thermal tolerance of this coral population. Understanding the processes that underpin the temporal changes in symbiont communities is key to assessing the acclimatization potential of reef corals.

  9. The first transcriptomes from field-collected individual whiteflies ( Bemisia tabaci, Hemiptera: Aleyrodidae):  a case study of the endosymbiont composition

    Science.gov (United States)

    Ndunguru, Joseph; Tumuhimbise, Robooni; Tairo, Fred; Guo, Jian-Yang; Vrielink, Alice; Blythe, Amanda; Kinene, Tonny; De Marchi, Bruno; Kehoe, Monica A.; Tanz, Sandra; Boykin, Laura M.

    2018-01-01

    Background: Bemisia tabaci species ( B. tabaci), or whiteflies, are the world’s most devastating insect pests. They cause billions of dollars (US) of damage each year, and are leaving farmers in the developing world food insecure. Currently, all publically available transcriptome data for B. tabaci are generated from pooled samples, which can lead to high heterozygosity and skewed representation of the genetic diversity. The ability to extract enough RNA from a single whitefly has remained elusive due to their small size and technological limitations. Methods: In this study, we optimised a single whitefly RNA extraction procedure, and sequenced the transcriptome of four individual adult Sub-Saharan Africa 1 (SSA1) B. tabaci. Transcriptome sequencing resulted in 39-42 million raw reads. De novo assembly of trimmed reads yielded between 65,000-162,000 Contigs across B. tabaci transcriptomes. Results: Bayesian phylogenetic analysis of mitochondrion cytochrome I oxidase (mtCOI) grouped the four whiteflies within the SSA1 clade. BLASTn searches on the four transcriptomes identified five endosymbionts; the primary endosymbiont Portiera aleyrodidarum and four secondary endosymbionts: Arsenophonus, Wolbachia, Rickettsia, and Cardinium spp. that were predominant across all four SSA1 B. tabaci samples with prevalence levels of between 54.1 to 75%. Amino acid alignments of the NusG gene of P. aleyrodidarum for the SSA1 B. tabaci transcriptomes of samples WF2 and WF2b revealed an eleven amino acid residue deletion that was absent in samples WF1 and WF2a. Comparison of the protein structure of the NusG protein from P. aleyrodidarum in SSA1 with known NusG structures showed the deletion resulted in a shorter D loop. Conclusions: The use of field-collected specimens means time and money will be saved in future studies using single whitefly transcriptomes in monitoring vector and viral interactions. Our method is applicable to any small organism where RNA quantity has limited

  10. Legume seeds and rapeseed press cake as substitutes for soybean meal in sow and piglet feed

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    Ewa Hanczakowska

    2013-11-01

    Full Text Available The possibility of replacing soybean meal with mixtures of rapeseed press cake (RPC and legume seeds in sow and piglet diets was evaluated in an experiment on 30 sows and their progeny. Group I (control received standard feed mixture containing soybean meal as the main protein source, group II – RPC mixed with fodder pea, group III – field bean, group IV – blue lupine, group V – yellow lupine. Weaned piglets received mixtures containing RPC and legume mixtures. Considerable differences were found in amino acid composition of proteins. Differences in the apparent digestibility of essential nutrients were statistically insignificant. Sows fed with field bean and yellow lupine gave birth to heaviest piglets. After weaning piglets receiving field bean were characterized by the best weight gains. It is concluded that mixing rapeseed cake with legume seeds allows for the complete replacement of soybean meal in sow diets and for partial replacement in piglet diets.

  11. Transfer of biologically fixed nitrogen to the non-legume component of mixed pastures

    International Nuclear Information System (INIS)

    Haystead, A.

    1983-01-01

    Pasture ecosystems are extremely diverse, as are the management procedures imposed upon them by the pastoralist. In low input pasture enterprises in marginal areas, legume nitrogen fixation is frequently (but not invariably) crucial to continued productivity. Legumes usually do not dominate a pasture and their role in transferring fixed nitrogen to a non-legume, frequently graminaceous, species is important. Methods for measuring this transfer are critically assessed in terms of their usefulness in realistic pasture environments. Existing techniques all have serious disadvantages in this respect. Isotopic studies of individual processes within the transfer system are described and some new lines of investigation are proposed. The value of isotopic studies in improving pasture management is discussed. (author)

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

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    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.

  13. 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.

  14. Risk assessment of clinical reactions to legumes in peanut-allergic children

    DEFF Research Database (Denmark)

    Jensen, Louise Bjerremann; Andersen, Milene; Skov, Per Stahl

    2008-01-01

    Peanut-allergic children might be at risk for reactions to other legumes. However, it is not always possible to perform multiple oral food challenges in children. On the basis of patient case history, in vitro diagnostic tests, and eventually food challenges, we aimed at developing an algorithm...... for risk assessment of possible clinical reactions to other legumes (soybean, lupine, fresh, and blanched green pea). Seventy-five consecutive patients with a positive oral food challenge to peanut were included in the study. All tests were run as part of the routine allergy examination. A high proportion...... of patients and/or caretakers refused the administered legume oral food challenges. Obtained diagnoses from histamine release did not correlate significantly to the outcome of the algorithm. Interestingly, threshold from peanut challenges did not correlate with the risk assessment.The algorithm presented...

  15. Proteome analysis of pod and seed development in the model legume Lotus japonicus

    DEFF Research Database (Denmark)

    Nautrup-Pedersen, G.; Dam, S.; Laursen, B. S.

    2010-01-01

    of the pod and seed proteomes in five developmental stages, paves the way for comparative pathway analysis and provides new metabolic information. Proteins were analyzed by two-dimensional gel electrophoresis and tandem-mass spectrometry. These analyses lead to the identification of 604 pod proteins and 965......Legume pods serve important functions during seed development and are themselves sources of food and feed. Compared to seeds, the metabolism and development of pods are not well-defined. The present characterization of pods from the model legume Lotus japonicus, together with the detailed analyses...... and photosynthesis. Proteins detected only in pods included three enzymes participating in the urea cycle and four in nitrogen and amino group metabolism, highlighting the importance of nitrogen metabolism during pod development. Additionally, five legume seed proteins previously unassigned in the glutamate...

  16. Induced mutations for the improvement of grain legumes in South East Asia (1975)

    International Nuclear Information System (INIS)

    1977-01-01

    The report is divided into seven sections containing papers on the following subjects: regional cooperation for improving grain legume production in South-East Asia and the role of FAO in this connection; national reports on the production and consumption of grain legumes (mainly beans, soybeans, peas, peanuts) in various Asian countries (separate reports for Pakistan, India, Sri Lanka, Bangladesh, Burma, Philippines, Indonesia, Papua New Guinea, Taiwan, and Australia). Specific papers are presented on the following: modifications of field pea; chickpea breeding at ICRISAT; mutation breeding in winged bean; mutation breeding in improving groundnut cultivars; and the consumption of grain legumes in Singapore. Finally, some conclusions and recommendations adopted by the participants of the meeting are presented

  17. Seed protein improvement in cereals and grain legumes

    International Nuclear Information System (INIS)

    1978-01-01

    Full text: This Symposium organized in co-operation with the Gesellschaft fur Strahlen- und Umweltforschung mbH (GSF), Neuherberg near Munich, Federal Republic of Germany, was the culmination of the eight year FAO/IAEA/GSF Co-ordinated Research Programme to Improve Protein Content and Quality of Crops by Nuclear Techniques The co-ordinated research programme has stimulated plant breeding in developing countries, assisted in the development of techniques for the identification and evaluation of nutritionally improved mutants and encouraged basic research on seed storage proteins. The Symposium comprised 90 scientific presentations plus equipment displays. Sixty-one scientific papers were orally presented and discussed in eight sessions. An additional 29 scientific contributions were presented as posters and were on display throughout the Symposium. One afternoon of the Symposium was devoted to examination and individual discussion of the poster displays. It was especially notable that this method of presentation and discussion of scientific results was very favourably received. Five items of scientific equipment demonstrated analytical systems in use for protein or amino acid assay in plant breeding programmes. The Symposium clearly demonstrated the reality of nutritional deficiencies in poor countries and outlined plant breeding strategies for overcoming these. Progress was reported in improving the nutritional quality of cereals (wheat, maize, rice, barley, sorghum, millet, triticale, oats), legumes (beans, peas, soybeans, field beans, chick peas, lentils, pigeon peas, cowpeas, grams, peanuts) and some other crops (cotton, buckwheat). Notable results have been achieved, but much of the work has been in progress less than 10 years, which is too short a time for the development, testing and release of commercial varieties. Chemical and nutritional assay methods, including some promising new methods were reviewed and assessed. Rapid developments in knowledge of the

  18. An analysis of the nutritive value of heat processed legume seeds for animal production using the DVE/OEB model : a review

    NARCIS (Netherlands)

    Yu, P.; Goelema, J.O.; Leury, B.J.; Tamminga, S.; Egan, A.R.

    2002-01-01

    Recently obtained information on structural and compositional effects of processing of legume seeds is reviewed, in relation to legume seed characteristics affecting digestive behavior and nutrient utilization. The emphasis is on (1) manipulation of digestive behavior by heat processing methods,

  19. Responses of legumes to rhizobia and arbuscular mycorrhizal fungi: A meta-analysis of potential photosynthate limitation of symbioses

    NARCIS (Netherlands)

    Kaschuk, G.; Leffelaar, P.A.; Giller, K.E.; Alberton, O.; Hungria, M.; Kuyper, T.W.

    2010-01-01

    Legumes are prized for their seed protein and lipid mass fractions. Since legumes spend up to 4–16% of photosynthesis on each of the rhizobial and arbuscular mycorrhizal (AM) fungal symbioses, it might be expected that positive responses in yield due to rhizobial and AM symbioses are accompanied by

  20. Piloting a Cooperative Extension Service Nutrition Education Program on First-Grade Children's Willingness to Try Foods Containing Legumes

    Science.gov (United States)

    Edwards, Cassandra S.; Hermann, Janice R.

    2011-01-01

    Many nutrition education campaigns targeting children in the United States focus on increasing fruit and vegetable consumption, but most don't specifically promote legumes. The project described here sought to pilot the effect of an Extension nutrition education program on first grade children's willingness to try foods containing legumes. A…

  1. Maize-grain legume intercropping for enhanced resource use efficiency and crop productivity in the Guinea savanna of northern Ghana

    NARCIS (Netherlands)

    Kermah, Michael; Franke, Angelinus C.; Adjei-nsiah, Samuel; Ahiabor, Benjamin D.K.; Abaidoo, Robert C.; Giller, Ken E.

    2017-01-01

    Smallholder farmers in the Guinea savanna practise cereal-legume intercropping to mitigate risks of crop failure in mono-cropping. The productivity of cereal-legume intercrops could be influenced by the spatial arrangement of the intercrops and the soil fertility status. Knowledge on the effect of

  2. Interaction between a tannin-containing legume and endophyte-infected tall fescue seed on lambs’ feeding behavior and physiology

    Science.gov (United States)

    It was hypothesized that a tannin-rich legume like sainfoin reduces the negative post-ingestive effects of ergot alkaloids in tall fescue. Thirty-two 4-month-old lambs were individually penned and randomly assigned to a 2X2 factorial arrangement with two legume species (1-sainfoin [SAN; ' 3% condens...

  3. Productivity and residual benefits of grain legumes to sorghum under semi-arid conditions in southwestern Zimbabwe

    NARCIS (Netherlands)

    Ncube, B.; Twomlow, S.J.; Wijk, van M.T.; Dimes, J.P.; Giller, K.E.

    2007-01-01

    The productivity and residual benefits of four grain legumes to sorghum (Sorghum bicolor) grown in rotation were measured under semi-arid conditions over three cropping seasons. Two varieties of each of the grain legumes; cowpea (Vigna unguiculata); groundnut (Arachis hypogaea); pigeon pea (Cajanus

  4. Protease inhibitors from processed legumes effectively inhibit superoxide generation in response to TPA.

    Science.gov (United States)

    Yavelow, J; Gidlund, M; Troll, W

    1982-01-01

    Crude extracts containing protease inhibitors from edible legumes (canned chick-peas, canned kidney beans and bean curd) were capable of blocking the superoxide response to human polymorphonuclear leukocytes produced by the tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Protease inhibitors purified from crude extracts more effectively blocked the superoxide response produced by TPA. Bowman-Birk soybean inhibitor was more effective in blocking this effect of the tumor promoter than Kunitz soybean inhibitor. The significance of protease inhibitors in edible legumes and the possible role of free oxygen radicals in tumor promotion are discussed.

  5. Upgrading of shamy wheat bread quality through supplement with flour of certain gamma irradiated legumes

    International Nuclear Information System (INIS)

    Nassef, A.E.

    1997-01-01

    Soybean flour,chick peas flour and lupines were irradiated at 0,5 and 10 kGy and individually used to replace 5,10 or 15% of wheat flour in shamy bread. The effect of supplementation of wheat flour with these legume flours on the major, chemical composition and nutritional quality of bread was studied. Results indicated that protein, ash and fiber contents of supplemented shamy bread were higher than the control. On the other hand, the amino acids of the shamy wheat bread supplemented irradiated legumes flour, improved the quality (water retention capacity, stailing rate and bread freshness) of bread

  6. Kidney bean: a major sensitizer among legumes in asthma and rhinitis patients from India.

    Directory of Open Access Journals (Sweden)

    Ramkrashan Kasera

    Full Text Available BACKGROUND: The prevalence of IgE mediated food allergies has increased over the last two decades. Food allergy has been reported to be fatal in highly sensitive individuals. Legumes are important food allergens but their prevalence may vary among different populations. The present study identifies sensitization to common legumes among Indian population, characterizes allergens of kidney bean and establishes its cross reactivity with other legumes. METHODOLOGY: Patients (n = 355 with history of legume allergy were skin prick tested (SPT with 10 legumes. Specific IgE (sIgE and total IgE were estimated in sera by enzyme-linked immunosorbent assay. Characterization of kidney bean allergens and their cross reactivity was investigated by immunobiochemical methods. Identification of major allergens of kidney bean was carried out by mass spectrometry. PRINCIPAL FINDINGS: Kidney bean exhibited sensitization in 78 (22.0% patients followed by chickpea 65 (18.0% and peanut 53 (15%. SPT positive patients depicted significantly elevated sIgE levels against different legumes (r = 0.85, p<0.0001. Sera from 30 kidney bean sensitive individuals exhibited basophil histamine release (16-54% which significantly correlated with their SPT (r = 0.83, p<0.0001 and sIgE (r = 0.99, p<0.0001. Kidney bean showed eight major allergens of 58, 50, 45, 42, 40, 37, 34 and 18 kDa on immunoblot and required 67.3±2.51 ng of homologous protein for 50% IgE inhibition. Inhibition assays revealed extensive cross reactivity among kidney bean, peanut, black gram and pigeon pea. nLC-MS/MS analysis identified four allergens of kidney bean showing significant matches with known proteins namely lectin (phytohemagglutinin, phaseolin, alpha-amylase inhibitor precursor and group 3 late embryogenesis abundant protein. CONCLUSION/SIGNIFICANCE: Among legumes, kidney bean followed by chick pea and peanut are the major allergic triggers in asthma and rhinitis patients in India

  7. Changes in nutritive value and herbage yield during extended growth intervals in grass-legume mixtures

    DEFF Research Database (Denmark)

    Elgersma, Anjo; Søegaard, Karen

    2018-01-01

    . Perennial ryegrass was sown with each of four legumes: red clover, white clover, lucerne and birdsfoot trefoil, and white clover was sown with hybrid ryegrass, meadow fescue and timothy. Effects of species composition on herbage yield, contents of N, neutral detergent fibre (NDF), acid detergent fibre (ADF......There is a lack of information on the effects of companion species in grass–legume mixtures on herbage yield and quality changes during prolonged growth. Such information is relevant for harvest planning and estimation of consequences for feeding value of conserved feed when harvesting is delayed...

  8. Peanut cross-reacting allergens in seeds and sprouts of a range of legumes

    DEFF Research Database (Denmark)

    Jensen, Louise Bjerreman; Pedersen, Mona H; Skov, Per Stahl

    2008-01-01

    protein extracts of seeds and sprouts (comprising cotelydons and hypocotyls/epicotyls) of peanut, soybean, green pea, blue lupine, mung bean, alfalfa, broad bean, and azuki bean were prepared. The reactivity of sera from 10 peanut-allergic patients to these extracts was analysed by indirect histamine......BACKGROUND: Recently, peanut-allergic patients have reported symptoms upon ingestion of bean sprouts produced from various legumes. OBJECTIVE: This study was designed to identify immunoreactivity to seeds and sprouts of legumes other than peanut in sera from peanut-allergic patients. METHODS: Crude...

  9. Genome-Wide Transcriptional Changes and Lipid Profile Modifications Induced by Medicago truncatula N5 Overexpression at an Early Stage of the Symbiotic Interaction with Sinorhizobium meliloti

    Directory of Open Access Journals (Sweden)

    Chiara Santi

    2017-12-01

    Full Text Available Plant lipid-transfer proteins (LTPs are small basic secreted proteins, which are characterized by lipid-binding capacity and are putatively involved in lipid trafficking. LTPs play a role in several biological processes, including the root nodule symbiosis. In this regard, the Medicago truncatula nodulin 5 (MtN5 LTP has been proved to positively regulate the nodulation capacity, controlling rhizobial infection and nodule primordia invasion. To better define the lipid transfer protein MtN5 function during the symbiosis, we produced MtN5-downregulated and -overexpressing plants, and we analysed the transcriptomic changes occurring in the roots at an early stage of Sinorhizobium meliloti infection. We also carried out the lipid profile analysis of wild type (WT and MtN5-overexpressing roots after rhizobia infection. The downregulation of MtN5 increased the root hair curling, an early event of rhizobia infection, and concomitantly induced changes in the expression of defence-related genes. On the other hand, MtN5 overexpression favoured the invasion of the nodules by rhizobia and determined in the roots the modulation of genes that are involved in lipid transport and metabolism as well as an increased content of lipids, especially galactolipids that characterize the symbiosome membranes. Our findings suggest the potential participation of LTPs in the synthesis and rearrangement of membranes occurring during the formation of the infection threads and the symbiosome membrane.

  10. 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.

  11. Genome-Wide Transcriptional Changes and Lipid Profile Modifications Induced by Medicago truncatula N5 Overexpression at an Early Stage of the Symbiotic Interaction with Sinorhizobium meliloti.

    Science.gov (United States)

    Santi, Chiara; Molesini, Barbara; Guzzo, Flavia; Pii, Youry; Vitulo, Nicola; Pandolfini, Tiziana

    2017-12-19

    Plant lipid-transfer proteins (LTPs) are small basic secreted proteins, which are characterized by lipid-binding capacity and are putatively involved in lipid trafficking. LTPs play a role in several biological processes, including the root nodule symbiosis. In this regard, the Medicago truncatula nodulin 5 (MtN5) LTP has been proved to positively regulate the nodulation capacity, controlling rhizobial infection and nodule primordia invasion. To better define the lipid transfer protein MtN5 function during the symbiosis, we produced MtN5-downregulated and -overexpressing plants, and we analysed the transcriptomic changes occurring in the roots at an early stage of Sinorhizobium meliloti infection. We also carried out the lipid profile analysis of wild type (WT) and MtN5-overexpressing roots after rhizobia infection. The downregulation of MtN5 increased the root hair curling, an early event of rhizobia infection, and concomitantly induced changes in the expression of defence-related genes. On the other hand, MtN5 overexpression favoured the invasion of the nodules by rhizobia and determined in the roots the modulation of genes that are involved in lipid transport and metabolism as well as an increased content of lipids, especially galactolipids that characterize the symbiosome membranes. Our findings suggest the potential participation of LTPs in the synthesis and rearrangement of membranes occurring during the formation of the infection threads and the symbiosome membrane.

  12. “Candidatus Gortzia shahrazadis”, a novel endosymbiont of Paramecium multimicronucleatum and a revision of the biogeographical distribution of Holospora-like bacteria

    Directory of Open Access Journals (Sweden)

    Valentina Serra

    2016-11-01

    Full Text Available Holospora spp. and Candidatus Gortzia infectiva, known as Holospora-like bacteria (HLB, are commonly found as nuclear endosymbionts of ciliates, especially the Paramecium genus. HLB are related by phylogenetic relationships, morphological features, and life cycles, which involve two alternating morphotypes: reproductive and infectious forms (RF, IF. In this paper we describe a novel species belonging to the Ca. Gortzia genus, detected in P. multimicronucleatum, a ciliate for which infection by an HLB has not been reported, discovered in India. This novel endosymbiont shows unusual and surprising features with respect to other HLB, such as large variations in IF morphology and the occasional ability to reproduce in the host cytoplasm. We propose the name of Candidatus Gortzia shahrazadis for this novel HLB . Moreover, we report two additional species of HLB from Indian Paramecium populations: Ca. Gortzia infectiva (from P. jenningsi, and H. obtusa (from P. caudatum; the latter is the first record of Holospora from a tropical country. Although tropical, we retrieved H. obtusa at an elevation of 706 m. corresponding to a moderate climate not unlike conditions where Holospora are normally found, suggesting the genus Holospora does exist in tropical countries, but restricted to higher elevations.

  13. “Candidatus Gortzia shahrazadis”, a Novel Endosymbiont of Paramecium multimicronucleatum and a Revision of the Biogeographical Distribution of Holospora-Like Bacteria

    Science.gov (United States)

    Serra, Valentina; Fokin, Sergei I.; Castelli, Michele; Basuri, Charan K.; Nitla, Venkatamahesh; Verni, Franco; Sandeep, Bhagavatula V.; Kalavati, Chaganti; Petroni, Giulio

    2016-01-01

    Holospora spp. and “Candidatus Gortzia infectiva”, known as Holospora-like bacteria (HLB), are commonly found as nuclear endosymbionts of ciliates, especially the Paramecium genus. HLB are related by phylogenetic relationships, morphological features, and life-cycles, which involve two alternating morphotypes: reproductive and infectious forms (RF, IF). In this paper we describe a novel species belonging to the “Ca. Gortzia” genus, detected in P. multimicronucleatum, a ciliate for which infection by an HLB has not been reported, discovered in India. This novel endosymbiont shows unusual and surprising features with respect to other HLB, such as large variations in IF morphology and the occasional ability to reproduce in the host cytoplasm. We propose the name of “Candidatus Gortzia shahrazadis” for this novel HLB. Moreover, we report two additional species of HLB from Indian Paramecium populations: “Ca. Gortzia infectiva” (from P. jenningsi), and H. obtusa (from P. caudatum); the latter is the first record of Holospora from a tropical country. Although tropical, we retrieved H. obtusa at an elevation of 706 m corresponding to a moderate climate not unlike conditions where Holospora are normally found, suggesting the genus Holospora does exist in tropical countries, but restricted to higher elevations. PMID:27867371

  14. Isoflavone rumen metabolites: A missing link in the benefits of legumes on grazing animal production

    Science.gov (United States)

    Clovers are widely used to add protein to ruminant diets. Clovers and other legumes also produce a class of small molecules called isoflavones. Isoflavones have estrogenic properties, which can interfere with reproduction in grazing ruminants, but they also have benefits. We identified potential b...

  15. Self-reseeding annual legumes for cover cropping in rainfed managed olive orchards

    Energy Technology Data Exchange (ETDEWEB)

    Ângelo Rodrigues, M.; Ferreira, I. Q.; Freitas, S.L.; Pires, J.M.; Arrobas, M.P.

    2015-07-01

    Given the environmental impact of nitrogen (N)-fertilizer manufacture and use, the sustainable management of agro-systems should be sought by growing N-fixing legumes. In this work, eleven self-reseeding annual legumes were grown in pure stands as mulching cover crops in a rainfed olive orchard managed without grazing animals. Dry matter yield, N content in above-ground biomass, groundcover percentage and persistence of the sown species were assessed during four growing seasons. All covers provided enough soil protection over the year, with living plants during the autumn/winter period and a mulch of dead residues during the summer. The legumes overcame a false break observed in the third year recovering the dominance of the covers in the fourth growing season. This means that the seed bank established in previous seasons ensured the persistence of the sown legume even when a gap in seed production occurred. The early-maturing cultivars produced less biomass and fixed less N (approx. 50 kg N/ha/yr present in the above-ground biomass) than the late-maturing ones, but would compete less for water since the growing cycle finished earlier in the spring. They seem best suited to being grown in dry farmed olive orchards with low N demand in drought prone regions. (Author)

  16. Draft genome sequence of pigeonpea (Cajanus cajan), an orphan legume crop of resource-poor farmers

    DEFF Research Database (Denmark)

    Varshney, Rajeev K.; Chen, Wenbin; Li, Yupeng

    2012-01-01

    Pigeonpea is an important legume food crop grown primarily by smallholder farmers in many semi-arid tropical regions of the world. We used the Illumina next-generation sequencing platform to generate 237.2 Gb of sequence, which along with Sanger-based bacterial artificial chromosome end sequences...

  17. Exploring socio-ecological niches for legumes in western Kenya smallholder farming systems

    NARCIS (Netherlands)

    Ojiem, J.O.

    2006-01-01

    Keywords: adaptability, agro-ecosystems, biophysical and socio-economic heterogeneity, economic benefits, N2-fixation, productivity.This thesis explores the potential of using herbaceous and grain legume species to improve soil fertility and farm productivity in the heterogeneous

  18. N2 Fixation by Grain Legume Varieties as Affected By Rhizobia ...

    African Journals Online (AJOL)

    acer

    ABSTRACT: Rhizobium – legume symbiotic association contributes considerable amount of N in tropical soils. However, low rainfall and high temperature in Sudano-Sahelian region of Northeastern. Nigeria may affect the Rhizobial population in the soil. Therefore, the influence of Rhizobia inoculation on N2 fixation by ...

  19. Plastid Genome Evolution in the Early-Diverging Legume Subfamily Cercidoideae (Fabaceae

    Directory of Open Access Journals (Sweden)

    Yin-Huan Wang

    2018-02-01

    Full Text Available The subfamily Cercidoideae is an early-branching legume lineage, which consists of 13 genera distributed in the tropical and warm temperate Northern Hemisphere. A previous study detected two plastid genomic variations in this subfamily, but the limited taxon sampling left the overall plastid genome (plastome diversification across the subfamily unaddressed, and phylogenetic relationships within this clade remained unresolved. Here, we assembled eight plastomes from seven Cercidoideae genera and conducted phylogenomic-comparative analyses in a broad evolutionary framework across legumes. The plastomes of Cercidoideae all exhibited a typical quadripartite structure with a conserved gene content typical of most angiosperm plastomes. Plastome size ranged from 151,705 to 165,416 bp, mainly due to the expansion and contraction of inverted repeat (IR regions. The order of genes varied due to the occurrence of several inversions. In Tylosema species, a plastome with a 29-bp IR-mediated inversion was found to coexist with a canonical-type plastome, and the abundance of the two arrangements of isomeric molecules differed between individuals. Complete plastome data were much more efficient at resolving intergeneric relationships of Cercidoideae than the previously used selection of only a few plastid or nuclear loci. In sum, our study revealed novel insights into the structural diversification of plastomes in an early-branching legume lineage, and, thus, into the evolutionary trajectories of legume plastomes in general.

  20. The effects of feeding mixed cereal-tree forage legume silages on ...

    African Journals Online (AJOL)

    The effects of feeding mixed cereal-tree forage legume silages on mild yield and composition in lactating. BZ Mugweni, M titterton, BV Maasdorp, JF Mupangwa, F Gandiya. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  1. Improving food and agricultural production. Thailand. Mutation breeding of food legumes

    International Nuclear Information System (INIS)

    Oram, R.N.

    1991-01-01

    The objectives of the present mission were to assist and advise mutation breeders on the induction, selection, utilization and maintenance of useful mutants in grain legumes, especially in soybean, mungbean, red kidney bean, sugar pea, cowpea and yard-long bean, and to provide consultation to plant breeders

  2. Productivity and nutritive value of three grass-legume mixtures in the ...

    African Journals Online (AJOL)

    Productivity and nutritive value of three grass-legume mixtures in the Sudan savannah zone Kano state, Nigeria. ... Results of the study indicated that Sorghum almum-Lablab purpureus mixture recorded numerically higher dry matter yield (7806 kg dm/hectare) compared to other mixtures, similarly leaf area for grass (46.4) ...

  3. Superparamagnetic adsorbents for high-gradient magnetic fishing of lectins out of legume extracts

    DEFF Research Database (Denmark)

    Heebøll-Nielsen, Anders; Dalkiær, M.; Hubbuch, Jürgen

    2004-01-01

    culinaris agglutinin (greater than or equal to 250 mg g(-1)) with dissociation constants in the micromolar range, though neither of these systems showed any selectivity for lectins in leguminous extracts. When the affinity supports were applied to carbohydrate containing legume extracts only the dextran...

  4. Content of amino acids and minerals in selected sorts of legumes

    Directory of Open Access Journals (Sweden)

    Stanislav Kráčmar

    2013-07-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 The aim of this study was to determine amino acid composition and mineral content in selected legume samples. All analyses were carried out at the laboratory temperature of 21±2 °C in triplicate. Amino acid composition was determined using the automatic amino acid analyzer AAA 400 with post-column derivatization. To assess the nutritional value of protein, index of essential amino acids (EAAI was calculated. Minerals were determined using the atomic absorption spectrometer AA 30. All results were statistically evaluated. The highest content of Cys, Glu, Asp, Leu, Lys and Arg was determined in seeds of G. max; only the content of Cys and His was lower than 10 g kg-1. The greatest total content of essential amino acids (EAA was discovered in soybeans, almost 128 g kg-1. The majority (Na, K, Mg, and Ca, trace (Fe, Zn, and Cr and toxic elements (Pb, Cd were determined. Legumes were rich in Mg and Ca-mainly G. max and Ph. vulgaris. The content of Mg was 2.1 g/1000g in soybeans and 1.6 g/1000g in common beans. Also in these two legumes the greatest concentration of toxic Pb was found. Values obtained during the determination of the chemical composition in samples of legumes and buckwheat products can be influenced by many factors, e.g. climatic conditions, location etc.

  5. Processing of legume seeds : effects on digestive behaviour in dairy cows

    NARCIS (Netherlands)

    Goelema, J.O.

    1999-01-01

    In this study, effects of toasting, expander treatment and pelleting on in situ rumen degradability and intestinal digestibility of legume seeds are described. Toasting decreases protein degradability of peas, lupins, faba beans and soybeans and starch degradability of peas and faba beans,

  6. Tree legumes in medium-term fallows: Nz fixation, nitrate recovery ...

    African Journals Online (AJOL)

    Legume effects on the fixation of atmospheric N and nitrate recovery were determined in a sub-humid, bi-modal rainfall system. Fallows improved with sesbania (Sesbania sesban) and tephrosia (Tephrosia vogellii) produced more biomass and fixed more N than those fallows improved with pigeonpea (Cajanus cajan) or ...

  7. The potential of legume pods as supplements to low quality roughages

    African Journals Online (AJOL)

    The potential of legume pods as supplements to low quality roughages. A.T. Ngwa, I.V. Nsahlai, M.L.K. Bonsi. Abstract. (South African J of Animal Science, 2000, 30, Supplement 1: 107-108). Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  8. 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

  9. Soil chemical properties and legume-cereal rotation benefits in an ...

    African Journals Online (AJOL)

    This research was conducted at the Department of Soil Science, University of Nigeria Teaching and Research Farm in 2008 and 2009 growing seasons. The objective was to evaluate the effects of edible grain legumes (cowpea and soybean) and velvet-bean/maize rotations on soil chemical properties and the contribution ...

  10. Exploratory trials on reinforcement of veld with legumes in the south ...

    African Journals Online (AJOL)

    In all, 17 legumes were involved, including the genera Coronilla, Desmodium, Glycine, Lespedeza, Lotus, Macroptillium, Medicago, Neotononia, Trifolium and Vigna. Only Coronilla varia (crownvetch) showed a satisfactory degree of persistence. However, crownvetch is slow to establish, is intolerant of waterlogging and has ...

  11. [Glycemic response to consumption of a cereals and legume (Phaseolus vulgaris) bar on healthy individuals].

    Science.gov (United States)

    Zambrano, Rosaura; Granito, Marisela; Valero, Yolmar

    2013-06-01

    The objective of this work was to formulate a cereals and legume (Phaseolus vulgaris) bar and assess its impact on the glycemic response of healthy individuals, in order to contribute to the healthy food supply beneficial to consumers. A mixture of cereals (corn and oats) and different percentages (20 and 30%) of Phaseolus vulgaris was used to formulate the bar. Additionally, a legume cereal bar without legumes (bar control) was prepared. The bar with 30% of Phaseolus vulgaris was selected through sensory evaluation, being scored with better flavor and texture. This combination of cereals and legumes aminoacid improves complementation and reaches the formulation criteria previously established. Chemical characterization indicated a higher protein content in the bar with 30% of Phaseolus vulgaris (13.55%) relative to the bar control (8.5%). The contents of fat, ash and dietary fiber did not differ between the two bars evaluated. However, the soluble fiber and resistant starch of the selected bar was a 32.05% and 18.67%, respectively, than in the control bar; this may contribute to decreasing the rate of glucose uptake. The selected bar presented a low glycemic index (49) and intermediate glycemic load (12.0) in healthy volunteers, which could lead to a possible reduction in the rate of absorption of glucose into the bloodstream, associated with a carbohydrate content of slow absorption. This bar represents a proposal of a healthy snack for the consumer.

  12. From the lab bench: Mixtures of grasses and legumes for extending the grazing season

    Science.gov (United States)

    A column was written to discuss how clovers and warm-season legumes, such as alfalfa and birdsfoot trefoil, in mixture with grasses can enhance the overall nutritive value of the overall forage, increase dry matter yield, and contribute nitrogen to the soil via the nitrogen fixing Rhizobia bacteria ...

  13. From the lab bench: Mixtures of grasses and legumes; a good or bad thing?

    Science.gov (United States)

    A column was written to discuss the advantages of complex mixtures of grasses and legumes. Historically, Kentucky pastures have been primarily composed of toxic endophyte-infected tall fescue, but Kentucky bluegrass and other grasses are presently encroaching tall fescue pastures. These other gras...

  14. Soil amendment with biochar increases the competitive ability of legumes via increased potassium availability

    NARCIS (Netherlands)

    Oram, N.J.; Van de Voorde, T.F.J.; Ouwehand, G.J.; Bezemer, T.M.; Mommer, Liesje; Jeffery, S.; van Groeningen, J.W.

    2014-01-01

    Soil amendment with biochar is currently proposed as a management strategy to improve soil quality and enhance plant productivity. Relatively little is known about how biochar affects plant competition, although it has been suggested that it can increase the competitive ability of legumes. This

  15. Estimation of extractable protein in botanical fractions of legume and grass species

    DEFF Research Database (Denmark)

    Solati, Zeinab; Jørgensen, Uffe; Eriksen, Jørgen

    2018-01-01

    With a globally strong interest in bio-based products such as fuels and chemicals, a feasible source of protein for the industry with positive economic impacts could be from leaves. However, more knowledge is needed on how to improve the content of extractable protein. Grasses and legumes have a ...

  16. Evaluating shade effects on crop productivity in sorghum-legume intercropping systems using support vector machines

    Science.gov (United States)

    Sorghum-legume intercropping has the potential to improve forage productivity, resource use efficiency, and forage quality under irrigation in the Southern High Plains of the United States. Crop production is conversion of solar radiation into biomass and solar radiation is wasted early in the seaso...

  17. Mineral composition of legumes forages cultivated under different levels of shade

    Directory of Open Access Journals (Sweden)

    João Carlos de Carvalho Almeida

    2015-02-01

    Full Text Available The objective of this study was to evaluate the composition of calcium, phosphorus and potassium, and the leaf: stem ratio of four tropical forage legumes: Calopogonium mucunoides (calopo, Pueraria phaseoloides (puero, Macrotyloma axillare (archer and Neonotonia wightii (perennial soybean, under different levels of artificial shade (0, 30, 50 and 70% in the summer and autumn seasons of 2006 and 2007, respectively. The experimental design was a randomized complete block in factorial 4x4 design with four replications. Was used SNK test at 5% probability to evaluate the effect of the legume species and regression analysis to test the effect of the level of shading. There was a trend of increase in the concentration of 3 independent minerals examined the season. In contrast, there was a reduction in the leaf: stem ratio and a slight increase in specific leaf area archer, perennial soybean and puero (R2 ? 40%, which suggests small effect of shading on the morphology of leaves of 3 forage legumes, which in turn have little effect concentrating minerals, besides these finding is confirmed the annual calopo behavior, which prevents their use as legume forage for the autumn season.

  18. Future prospects for ascochyta blight resistance breeding in cool season food legumes

    Directory of Open Access Journals (Sweden)

    Diego eRubiales

    2012-02-01

    Full Text Available Legume cultivation is strongly hampered by the occurrence of ascochyta blights. Strategies of control have been developed but only marginal successes have been achieved. Breeding for disease resistance is regarded the most cost efficient method of control. Significant genetic variation for disease resistance exists in most legume crops with numerous germplasm lines maintained, providing an excellent resource for plant breeders. Fast and reliable screening methods have been adjusted to fulfil breeding programmes needs. However, the complex inheritance controlled quantitatively by multiple genes, have been difficult to manipulate. Successful application of biotechnology to ascochyta blight resistance breeding in legume crops will facilitate both a good biological knowledge of the crops and of the mechanisms underlying resistance. The current focus in applied breeding is leveraging biotechnological tools to develop more and better markers to speed up the delivery of improved cultivars to the farmer. To date, however, progress in marker development and delivery of useful markers has been slow. The limited saturation of the genomic regions bearing putative QTLs in legume crops makes difficult to identify the most tightly-linked markers

  19. Nodulation of tree legumes and the ecology of their native rhizobial populations in tropical soils

    NARCIS (Netherlands)

    Bala, A.; Murphy, P.J.; Osunde, A.O.; Giller, K.E.

    2003-01-01

    A legume introduced into a new area will only form nodules and fix nitrogen if compatible rhizobia are present in the soil. Using 25 (60 in the case of Sesbania sesban) soils sampled from tropical areas of Africa, Asia and Latin America, we examined the nodulation of four agroforestry tree species

  20. Condensed tannins in some forage legumes: their role in the prevention of ruminant pasture bloat.

    Science.gov (United States)

    Lees, G L

    1992-01-01

    For the past 20 years, the focus in our laboratory has been on finding the causes of ruminant pasture bloat and eventually breeding a bloat-safe alfalfa (Medicago sativa L.); i.e., with bloat potential reduced to the economic threshold. In the mid-seventies, the mechanisms of bloat were explored and found to be more physical than chemical. Characteristic of all bloating legumes after ingestion was a very rapid initial rate of ingestion by rumen microbes. Through the study of bloating and non-bloating legumes, factors were elucidated in the plant that would slow this process. One of these factors was the presence of condensed tannins in the herbage. Some of the non-bloating legumes contained these secondary metabolites, but no condensed tannins were found in any of the bloating legumes. Therefore, species containing an appreciable amount of condensed tannins in their leaves and stems are considered to be non-bloating. Conventional breeding methods have not been successful in producing an alfalfa with condensed tannins in its herbage. New approaches using tissue culture techniques are being attempted, but genetic engineering has the greatest potential for success.

  1. Grain legume impacts on soil biological processes in Sub-Saharan Africa

    Science.gov (United States)

    Grain legumes occupy about 20 million hectares in Africa. The major crops are cowpea (Vigna unguiculata), which is grown on about 11 million hectares mostly in west Africa, and common bean (Phaseolus vulgaris), grown on about 5 million hectares mostly in eastern and southern Africa. These grain le...

  2. The Role of Micro-Ribonucleic Acids in Legumes with a Focus on Abiotic Stress Response

    Directory of Open Access Journals (Sweden)

    Nitin Mantri

    2013-11-01

    Full Text Available Legumes are special group of N-fixing plants that are an essential component of cropping system and important source of food and feed for human and animal consumption. Like other crops, the productivity of legumes is threatened by environmental stresses caused due to global climate change. Abiotic stress tolerance is complex trait involving a suite of genes, the expression of which is controlled by transcription factors including gene and/or polypeptide sequences. Recently, micro-ribonucleic acids (miRNAs have been increasingly recognized for their role in regulating the synthesis of polypeptides from different messenger ribonucleic acids (mRNAs including those that act as transcription factors. This review summarizes the current knowledge on the role of different miRNAs in response to main abiotic stresses in legumes. We found consistent as well as conflicting results within and between different legume species. This highlights that we have barely scratched the surface and very comprehensive and targeted experiments will be required in future to underpin the role of miRNAs in controlling the expression of important genes associated with abiotic stress tolerances.

  3. Forage production of grass-legume binary mixtures on Intermountain Western USA irrigated pastures

    Science.gov (United States)

    A well-managed irrigated pasture is optimized for forage production with the use of N fertilizer which incurs extra expense. The objective was to determine which binary grass-legume mixture and mixture planting ratio of tall fescue (Festuca arundinacea Schreb.) (TF), meadow brome (Bromus bieberstei...

  4. 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…

  5. THE NUTRITIONAL COMPOSITION AND ACCEPTABILITY OF CACTI (Opuntia ficus indica)-LEGUME MIXED SILAGE

    OpenAIRE

    J. GUSHA; S. KATSANDE; P.I. ZVINOROVA; S. NCUBE

    2013-01-01

    The potential of making silage using dry browse legume hay (Acacia angustissima, Leucaena leucocephala, Calliandra callothrysus and Macroptilium Atropurpureum) mixed with fresh cactus (Opuntia ficus-indica) for winter supplementation of veld grass was evaluated using the proximate, tannins and the pH analyses. Chemical analysis revealed that N values were significantly increased (P

  6. 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

  7. Crimped Cover Crop Legume Residue Effects on Sweet Corn (Zea mays L.) Yield in Puerto Rico

    Science.gov (United States)

    Crimped legume residue can control weeds and supply N for sweet corn production if biomass is sufficient. Three sweet corn (Zea mays L.) open pollinated variety “Suresweet 2011” plantings (April, 2013; July 2013; February 2014) were conducted on an Oxisol (very fine, kaolinitic, isohyperthermic and...

  8. Selection and breeding of grain legumes in Australia for enhanced nodulation and N2 fixation

    International Nuclear Information System (INIS)

    Herridge, D.F.; Holland, J.F.; Rose, I.A.; Redden, R.J.

    1998-01-01

    During the period 1980-87, the areas sown to grain legumes in Australia increased dramatically, from 0.25 Mha to 1.65 Mha. These increases occurred in the western and southern cereal belts, but not in the north which N continued to be supplied by the mineralization of soil organic matter. Therefore, there was a need to promote the use of N 2 -fixing legumes in the cereal-dominated northern cropping belt. Certain problems had to be addressed before farmers would accept legumes and change established patterns of cropping. Here we describe our efforts to improve N 2 fixation by soybean, common bean and pigeon pea. Selection and breeding for enhanced N 2 fixation of soybean commenced at Tamworth in 1980 after surveys of commercial crops indicated that nodulation was sometimes inadequate, particularly on new land, and that the levels of fixed-N inputs were variable and often low. Similar programmes were established in 1985 (common bean) and 1988 (pigeon bean). Progress was made in increasing N 2 fixation by these legumes towards obtaining economic yields without fertilizer N and contributing organic N for the benefit of subsequent cereal crops

  9. 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

    . 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...

  10. Legume Protein Isolates for Stable Acidic Emulsions Prepared by Premix Membrane Emulsification

    NARCIS (Netherlands)

    Ladjal Ettoumi, Yakoub; Berton-Carabin, Claire; Chibane, Mohamed; Schroën, Karin

    2017-01-01

    Proteins originating from dry legumes are not that much used in food formulations, yet, they are interesting components from a sustainability point of view, and could have interesting functional properties, e.g. for emulsion preparation. Therefore, this work focuses on the potential of the water

  11. The Effects of Fortification of Legumes and Extrusion on the Protein Digestibility of Wheat Based Snack

    Directory of Open Access Journals (Sweden)

    Swapnil S. Patil

    2016-04-01

    Full Text Available Cereal food products are an important part of the human diet with wheat being the most commonly consumed cereal in many parts of the world. Extruded snack products are increasing in consumer interest due to their texture and ease of use. However, wheat based foods are rich in starch and are associated with high glycaemic impact products. Although legume materials are generally rich in fibre and protein and may be of high nutritive value, there is a paucity of research regarding their use in extruded snack food products. The aim of this study was to prepare wheat-based extrudates using four different legume flours: lentil, chickpea, green pea, and yellow pea flour. The effects of adding legumes to wheat-based snacks at different levels (0%, 5%, 10%, and 15% during extrusion were investigated in terms of protein digestibility. It was observed that fortification of snacks with legumes caused a slight increase in the protein content by 1%–1.5% w/w, and the extrusion technique increased the protein digestibility by 37%–62% w/v. The product developed by extrusion was found to be low in fat and moisture content.

  12. Method Development to Increase Protein Enrichment During Dry Fractionation of Starch-Rich Legumes

    NARCIS (Netherlands)

    Pelgrom, P.J.M.; Boom, R.M.; Schutyser, M.A.I.

    2015-01-01

    A facile method was developed to establish milling settings that optimally separate starch granules from protein bodies and cell wall fibres for starch-rich legumes. Optimal separation was obtained for pea, bean, lentil and chickpea when the particle size distribution curve of flour and isolated

  13. Enhancing Legume Ecosystem Services through an Understanding of Plant–Pollinator Interplay

    Science.gov (United States)

    Suso, María J.; Bebeli, Penelope J.; Christmann, Stefanie; Mateus, Célia; Negri, Valeria; Pinheiro de Carvalho, Miguel A. A.; Torricelli, Renzo; Veloso, Maria M.

    2016-01-01

    Legumes are bee-pollinated, but to a different extent. The importance of the plant–pollinator interplay (PPI), in flowering crops such as legumes lies in a combination of the importance of pollination for the production service and breeding strategies, plus the increasing urgency in mitigating the decline of pollinators through the development and implementation of conservation measures. To realize the full potential of the PPI, a multidisciplinary approach is required. This article assembles an international team of genebank managers, geneticists, plant breeders, experts on environmental governance and agro-ecology, and comprises several sections. The contributions in these sections outline both the state of the art of knowledge in the field and the novel aspects under development, and encompass a range of reviews, opinions and perspectives. The first three sections explore the role of PPI in legume breeding strategies. PPI based approaches to crop improvement can make it possible to adapt and re-design breeding strategies to meet both goals of: (1) optimal productivity, based on an efficient use of pollinators, and (2) biodiversity conservation. The next section deals with entomological aspects and focuses on the protection of the “pest control service” and pollinators in legume crops. The final section addresses general approaches to encourage the synergy between food production and pollination services at farmer field level. Two basic approaches are proposed: (a) Farming with Alternative Pollinators and (b) Crop Design System. PMID:27047514

  14. Legumes as suppliers of nitrogen to pasture. | B.W. | African Journal ...

    African Journals Online (AJOL)

    Nitrogen losses ranging between 0, 16 and 0, 26 kg/ha/day may occur direct from the soil of grazed legume pastures while removal of animal products from the system represents a major loss of N from the system in the form of protein. On a global basis it has been estimated that annully 200 million tons of N are fixed ...

  15. Enhancing legume ecosystem services through an understanding of plant-pollinator interplay

    Directory of Open Access Journals (Sweden)

    Maria Jose eSuso

    2016-03-01

    Full Text Available Legumes are bee-pollinated, but to a different extent. The importance of the plant-pollinator interplay (PPI, in flowering crops such as legumes lies in a combination of the importance of pollination for the production service and breeding strategies, plus the increasing urgency in mitigating the decline of pollinators through the development and implementation of conservation measures. To realize the full potential of the PPI, a multidisciplinary approach is required. This article assembles an international team of genebank managers, geneticists, plant breeders, experts on environmental governance and agro-ecology, and comprises several sections. The contributions in these sections outline both the state of the art of knowledge in the field and the novel aspects under development, and encompass a range of reviews, opinions and perspectives. The first three sections explore the role of PPI in legume breeding strategies. PPI based approaches to crop improvement can make it possible to adapt and re-design breeding strategies to meet both goals of: 1 optimal productivity, based on an efficient use of pollinators, and 2 biodiversity conservation. The next section deals with entomological aspects and focuses on the protection of the pest control service and pollinators in legume crops. The final section addresses general approaches to encourage the synergy between food production and pollination services at farmer field level. Two basic approaches are proposed: a Farming with Alternative Pollinators (FAP and b Crop Design System (CDS.

  16. The pulvinus endodermal cells and their relation to leaf movement in legumes of the Brazilian cerrado.

    Science.gov (United States)

    Rodrigues, T M; Machado, S R

    2007-07-01

    Legume pulvini have a clearly delimited endodermis, whose variable content has been associated with the velocity and type of leaf movement: pulvini in leaves with fast nastic movement contain starch grains; pulvini in leaves with slow nastic movements have calcium oxalate crystals as well as starch grains in the endodermis. However, the studies carried out to date have involved few legume species. This study therefore purported to examine the consistency of this hypothesis in other legumes. Thus, the structure and content of the pulvinus endodermal cells of nine legumes of the Brazilian cerrado, with different types and velocities of leaf movement, were investigated: slow nyctinastic and heliotropic movements ( BAUHINIA RUFA, COPAIFERA LANGSDORFFII, SENNA RUGOSA - Caesalpinioideae; ANDIRA HUMILIS and DALBERGIA MISCOLOBIUM - Faboideae; STRYPHNODENDRON POLYPHYLLUM - Mimosoideae), slow heliotropic movement ( ZORNIA DIPHYLLA - Faboideae), and fast seismonastic and slow nyctinastic and heliotropic movements ( MIMOSA RIXOSA and MIMOSA FLEXUOSA - Mimosoideae). Samples were prepared following standard plant anatomy and ultrastructure techniques. The endodermis of all the species contains starch grains. In the species displaying only slow movements, calcium oxalate prismatic crystals were observed in addition to starch grains, except in ZORNIA DIPHYLLA. In conclusion, oxalate crystals occur only in endodermal cells of pulvini that display slow movements, while starch grains are always present in pulvinus endodermal cells of plants with any kind of movement.

  17. Alterations in biochemical and physiological characters in radiation-induced mutants of grain legumes

    International Nuclear Information System (INIS)

    Mueller, H.P.

    1984-01-01

    Selected examples from different grain legumes are studied. The biochemically and physiologically detectable alterations in distintc characters as caused by the action of mutant genes are presented comparatively. The interactions between different mutant genes in order to evaluated the influence of the genotypic constitution on the expression of mutated genes are emphasized. (M.A.C.) [pt

  18. 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...

  19. A comparison of a number of annual cool season legumes under ...

    African Journals Online (AJOL)

    Fifteen annual cool season legumes were compared under dryland conditions on two sites in the Dohne Sourveld. These sites were Dohne, with a mild but dry winter and an average rainfall of 743 mm per year, and Grasslands, a colder, wetter site. Vicia spp were among the highest-yielding cultivars at both sites. At Dohne ...

  20. A comparison of the dry matter yields of perennial legumes in the ...

    African Journals Online (AJOL)

    , in the Dohne Sourveld. These sites were Dohne, which has a mild, but dry winter and an average of 743 mm of rainfall per year, and Grasslands, which is a colder site with an average rainfall of 866 mm per year. The legumes were compared ...