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Mycorrhizal induction of phenolic compounds and antioxidant properties of fungi and seedlings during the early steps of symbiosis.

Reis, Filipa S.; Ferreira, Isabel C.F.R.; Barros, Lillian; Santos-Buelga, Celestino; Martins, Anabela
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.03%
Ectomycorrhizal (ECM) symbiosis plays a major role in nutrient cycling and the functioning of forest ecosystems. Trees with well developed ectomycorrhizas are more resistant to environmental stresses such as drought and to biotic stresses such as root pathogens. The establishment of ECM symbiosis is triggered by signals produced by both partners. These signals lead to morphological changes and a complex development of specific structures in both the plant root and the fungus. The development of the ECM fungi, Paxillus involutus and Pisolithus arhizus, in presence and absence of the symbiont – Pinus pinaster- was evaluated, as well as their antioxidant properties and phenolic compounds composition in response to the symbiotic association. ECM fungi grew less in the presence of Pinus pinaster, with Pisolithus arhizus being less affected in growth and thus being more adapted to this association. Protocatechuic acid was found only in Paxillus involutus, while Pinus pinaster roots, both in association and isolated, proved to have other phenolic acids, such as p-hydroxybenzoic and p-coumaric acids. The symbiosis between Paxillus involutus and Pinus pinaster had no major effects on the symbionts, while the association between Pisolithus arhizus and Pinus pinaster seems to generally decrease the antioxidant effects of both symbionts...

Effect of the mycorrhizal symbiosis time in the antioxidant activity of fungi and Pinus pinaster roots, stems and leaves

Reis, Filipa S.; Ferreira, Isabel C.F.R.; Martins, Anabela
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.8%
The ectomycorrhizal (ECM) symbiosis that develops between the roots of host trees and the soil ECM fungi is an important factor towards the survival, health and growth of these trees, as it stimulates their water and nutrient uptake. Ectomycorrhizal colonization can result in the deposition of phenolic compounds in peripheral cortex cells and a similar answer can be recognized as one way of plant defense against pathogenic infections. The aim of the present work was the evaluation of antioxidant potential of the ectomycorrhizal fungi, Paxillus involutus and Pisolithus arhizus, in presence and absence of the symbiont – Pinus pinaster –, in response to the symbiotic association, under different contact periods (45 days and 48 h). Phenolic contents in mycelia, culture media and plant leaves, stems and roots were determined by Folin-Ciocalteu assay, and their antioxidant properties were evaluated by three in vitro assays: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power and lipid peroxidation inhibition through B-carotene bleaching inhibition. Comparing the response of the symbionts to the host species, Pinus pinaster benefited most with the association, because it generally decreases the phenolics content and the antioxidant activity values in the presence of both ectomycorrhizal fungi along time. Pisolithus arhizus also decreased...

Antioxidants in Pinus Pinaster roots and mycorrhizal fungi during the early steps of symbiosis

Carocho, Márcio; Barros, Lillian; Ferreira, Isabel C.F.R.; Barreira, João C.M.; Martins, Anabela
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.94%
Ectomycorrhizal symbiosis between fungi mycelia and the roots of some plants could have important effects in the levels of antioxidants of both partners. In the present work, the effects of co-culture period in the antioxidant properties and antioxidants (phenolics, tocopherols and sugars) production during early steps of in vitro mycorrhization (Pinus pinaster-Pisolithus arhizus and Pinus pinaster-Paxillus involutus) were evaluated. The studied parameters were determined in each culture element (root, mycelium and medium) in order to understand the response of each partner to the symbiotic association. P. arhizus proved to be more compatible with P. pinaster than P. involutus, since the antioxidant activity in the latter species increased from 48 to 72 h, while P. arhizus antioxidant properties decreased at the same period (indicative of less oxidative stress). Despite P. involutus proved to be less suitable to be included in forestation programs using mycorrhization processes, it revealed a higher potential for bioactive compounds production in the early steps of symbiosis. A maximal value of phenolics content was obtained after the first 6 h.

Proposta de um indicador para monitorar a evolução da simbiose industrial em parques eco-industriais segundo a perspectiva de sistemas dinâmicos

Felicio, Miriã Camargo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/01/2013 PT
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27.33%
Os Parques Eco-Industriais (EIP - Eco-Industrial Park) surgiram como um novo modelo de organização espacial para arranjos industriais. Uma característica importante para um EIP é a adoção do conceito de simbiose industrial (SI), em que as empresas reutilizam resíduos em busca de um sistema fechado, diminuindo impacto ambiental. Há propostas para avaliar o fluxo de resíduos e a simbiose de um EIP por meio de indicadores detalhados em um determinado momento. Porém, trata-se de uma visão estática do parque na qual seria possível que os agentes implementassem mudanças para construir uma situação de sistema fechado ideal. Pesquisas recentes demonstram que essa abordagem enfrenta algumas limitações, uma vez que o processo de simbiose depende das decisões rotineiras e individuais de cada ator, empresários, técnicos e agenciadores, as quais podem alterar a dinâmica do fluxo de material no decorrer do tempo. A fim de contribuir, propõe-se um indicador de simbiose industrial diferente, elaborado segundo a abordagem do parque como um sistema dinâmico. Trata-se de uma ferramenta capaz de monitorar o nível de simbiose de um parque ao longo do tempo. Diferencia-se por permitir que a organização agenciadora possa implementar políticas de incentivo à simbiose industrial...

Inclusão do conceito de simbiose industrial na definição do layout: uma proposta conceitual; Including the industrial symbiosis concept in layout definition: a conceptual proposal

Camparotti, Carlos Eduardo Soares
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 10/04/2015 PT
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36.8%
O aspecto ambiental está cada vez mais presente no cotidiano das empresas, as quais necessitam reduzir custos e diminuir seus impactos ambientais sempre, concomitantemente a isso tem a necessidade de diminuir a disposição de resíduos na natureza e a extração desenfreada de recursos naturais finitos. Um conceito importante encontrado na literatura é a Simbiose Industrial (SI), a qual busca reutilizar resíduos para obter um sistema fechado com a diminuição de impactos ambientais. A SI ocorre entre empresas e estas são preferíveis que estejam dentro de um parque para maior eficiência, portanto pode-se considerar que a proximidade geográfica influencia no sucesso dela e que o arranjo físico do parque deve ser planejado para atingir melhores resultados. Este trabalho propõe um procedimento composto por seis passos, baseados principalmente no modelo Systematic Layout Planning (SLP) de Muther (1973) para planejar o layout de empresas que participam da SI dentro de um sistema com limites definidos, de forma a encontrar o melhor arranjo físico que favoreça as trocas simbióticas e os relacionamentos criados. O procedimento proposto direciona desde a coleta de dados, passando pelo matching, análise e fluxo, até o estabelecimento das inter-relações das empresas dentro do espaço. Para demonstrar a aplicação do procedimento e os possíveis resultados...

Trophic plasticity in the cnidarian-dinoflagellate symbiosis; Plasticidade trófica na simbiose entre cnidários e dinoflagelados

Leal, Miguel Albuquerque da Costa
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
37.1%
Coral reefs are of utmost ecological and economical importance but are currently in global decline due to climate change and anthropogenic disturbances. Corals, as well as other cnidarian species, live in symbiosis with photosynthetic dinoflagellates of the genus Symbiodinium. This relationship provides the cnidarian host with alternative metabolic pathways, as the symbionts translocate photosynthetic carbon to the animal. Besides this autotrophic nutrition mode, symbiotic cnidarians also take up organic matter from the environment (heterotrophy). The nutritional balance between auto- and heterotrophy is critical for the functioning, fitness and resilience of the cnidariandinoflagellate symbiosis. New methodological approaches were developed to better understand the role of auto- and heterotrophy in the ecophysiology of cnidarians associated with Symbiodinium, and the ecological implications of this trophic plasticity. Specifically, the new approaches were developed to assess photophysiology, biomass production of the model organism Aiptasia sp. and molecular tools to investigate heterotrophy in the cnidarian-dinoflagellate symbiosis. Using these approaches, we were able to non-invasively assess the photophysiological spatial heterogeneity of symbiotic cnidarians and identify spatial patterns between chlorophyll fluorescence and relative content of chlorophyll a and green-fluorescent proteins. Optimal culture conditions to maximize the biomass production of Aiptasia pallida were identified...

Chickpea rhizobia symbiosis genes are highly conserved across multiple Mesorhizobium species

Laranjo, Marta; Alexandre, Ana; Rivas, Raul; Velázquez, Encarna; Young, J. Peter W.; Oliveira, Solange
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Artigo de Revista Científica Formato: 7862 bytes; application/pdf
ENG
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37.15%
ABSTRACT Chickpea has been considered as a restrictive host for nodulation by rhizobia. However, recent studies have reported that several Mesorhizobium species may effectively nodulate chickpea. With the purpose of investigating the evolutionary relationships between these different species with the ability of nodulating the same host, we analysed 21 Portuguese chickpea rhizobial isolates. Symbiosis genes nifH and nodC were sequenced and used for phylogenetic studies. Symbiotic effectiveness was determined to evaluate its relationship with symbiosis genes. The comparison of 16S rRNA gene-based phylogeny with the phylogenies based on symbiosis genes revealed evidence of lateral transfer of symbiosis genes across different species. Chickpea is confirmed as a nonpromiscuous host. Although chickpea is nodulated by many different species, they share common symbiosis genes, suggesting recognition of only a few Nod factors by chickpea. Our results suggest that sequencing of nifH or nodC genes can be used for rapid detection of chickpea mesorhizobia.

WEED MANAGEMENT UNDER NO-TILL TO INCREASE THE BENEFITS OF THE TRIPARTITE SYMBIOSIS

Alho, Luis; Carvalho, Mário; Goss, Michael; Brito, Isabel
Fonte: 19th ISTRO Meeting Publicador: 19th ISTRO Meeting
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.94%
In southern regions of Europe subclover (Trifolium subterraneum L.), inoculated with rhizobia, is commonly sown in acid soils that are marginal for arable crop production. The rate of success of these pastures is small both in terms of plant growth and nodulation with the introduced rhizobia. Manganese toxicity is frequently considered to be a contributory factor. Nevertheless, other native legumes, particularly Ornithopus, are commonly found to grow satisfactorily under these conditions. Knowing that Ornithopus is a highly mycotrophic plant, we hypothesized that preserving the extraradical mycelium (ERM) of mycorrhizal fungi associated with its roots at the time for seeding subclover would allow for a better performance of subclover through an enhanced tripartite symbiosis (legume-rhizobia-mycorrhizal fungi). To test this hypothesis a pot experiment was conducted in a soil where manganese toxicity was known to occur. Ornithopus compressus and Silene gallica (a non-mycotrophic plant) and two different weed control methods were used to promote different levels of clover AM colonization. The weeds were allowed to growth for 6 weeks and controlled by glyphosate or mechanically with soil disturbance, prior to the seeding of inoculated subclover (T. subterraneum cv. Nungarin). The only treatment where the ERM was kept intact was Ornithopus controlled by glyphosate. Three weeks after planting...

Industrial symbiosis potential of the Sines oil refinery – environmental and economic evaluation

Lopes, Miguel Ângelo de Freitas
Fonte: Faculdade de Ciências e Tecnologia Publicador: Faculdade de Ciências e Tecnologia
Tipo: Dissertação de Mestrado
Publicado em //2013 ENG
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37.1%
Dissertação para obtenção do Grau de Mestre em Engenharia do Ambiente – Perfil Gestão e Sistemas Ambientais; Industrial symbiosis is an application of industrial ecology that consists of a collaborative approach between different industries and firms aimed at improving their environmental and economic performance involving the exchange of waste/byproducts as substitutes for raw materials. This collaboration is conditioned by the geographic proximity between industries and may face some information, economic, regulatory or motivational barriers. The main objective of this thesis was to develop a methodology to find and evaluate new potential exchanges in light of industrial symbiosis and to apply it to Sines oil refinery case study. The methodology was divided into four phases. The first phase is where, through the analysis of similar case studies, the potential new exchanges are uncovered.The second was made based on a literature review on the main barriers to industrial symbiosis development. This phase was developed to swiftly filter potential synergies that would face barriers to its development. The other two phases were only applied to the potential synergies that successfully passed the “filter”. Those phases consisted of an environmental evaluation through a LCA and a financial analysis. The application of the methodology showed two new potential synergetic possibilities for the Sines oil refinery. The results of the evaluation of those potential synergies were very promising both environmentally and financially. This research thus demonstrates the potential and benefits associated with the development of industrial symbiosis networks if the barriers to this development can be successfully surpassed.

Hawksbill turtles visit moustached barbers: cleaning symbiosis between eretmochelys imbricata and the shrimp stenopus hispidus

Sazima,Ivan; Grossman,Alice; Sazima,Cristina
Fonte: Instituto Virtual da Biodiversidade | BIOTA - FAPESP Publicador: Instituto Virtual da Biodiversidade | BIOTA - FAPESP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2004 EN
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This seems to be the first record of cleaning symbiosis between marine turtles and shrimps. During their foraging on the reef flat, the turtles regularly visited and posed at the stations. The same stations were visited by a few species of reef fishes, which posed and were cleaned by the shrimps. We suggest that cleaning symbiosis between turtles and shrimps is widespread and went unrecognised due to the superficial resemblance between a resting turtle and a posing and cleaned one. Additionally, we submit a putative origin for the cleaning symbiosis between marine turtles and cleaner shrimps following a few simple behavioural steps.

Expression Islands Clustered on the Symbiosis Island of the Mesorhizobium loti Genome

Uchiumi, Toshiki; Ohwada, Takuji; Itakura, Manabu; Mitsui, Hisayuki; Nukui, Noriyuki; Dawadi, Pramod; Kaneko, Takakazu; Tabata, Satoshi; Yokoyama, Tadashi; Tejima, Kouhei; Saeki, Kazuhiko; Omori, Hirofumi; Hayashi, Makoto; Maekawa, Takaki; Sriprang, Rutch
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /04/2004 EN
Relevância na Pesquisa
27.25%
Rhizobia are symbiotic nitrogen-fixing soil bacteria that are associated with host legumes. The establishment of rhizobial symbiosis requires signal exchanges between partners in microaerobic environments that result in mutualism for the two partners. We developed a macroarray for Mesorhizobium loti MAFF303099, a microsymbiont of the model legume Lotus japonicus, and monitored the transcriptional dynamics of the bacterium during symbiosis, microaerobiosis, and starvation. Global transcriptional profiling demonstrated that the clusters of genes within the symbiosis island (611 kb), a transmissible region distinct from other chromosomal regions, are collectively expressed during symbiosis, whereas genes outside the island are downregulated. This finding implies that the huge symbiosis island functions as clustered expression islands to support symbiotic nitrogen fixation. Interestingly, most transposase genes on the symbiosis island were highly upregulated in bacteroids, as were nif, fix, fdx, and rpoN. The genome region containing the fixNOPQ genes outside the symbiosis island was markedly upregulated as another expression island under both microaerobic and symbiotic conditions. The symbiosis profiling data suggested that there was activation of amino acid metabolism...

A Medicago truncatula phosphate transporter indispensable for the arbuscular mycorrhizal symbiosis

Javot, Hélène; Penmetsa, R. Varma; Terzaghi, Nadia; Cook, Douglas R.; Harrison, Maria J.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.25%
The arbuscular mycorrhizal (AM) symbiosis is a mutualistic endosymbiosis formed by plant roots and AM fungi. Most vascular flowering plants have the ability to form these associations, which have a significant impact on plant health and consequently on ecosystem function. Nutrient exchange is a central feature of the AM symbiosis, and AM fungi obtain carbon from their plant host while assisting the plant with the acquisition of phosphorus (as phosphate) from the soil. In the AM symbiosis, the fungus delivers Pi to the root through specialized hyphae called arbuscules. The molecular mechanisms of Pi and carbon transfer in the symbiosis are largely unknown, as are the mechanisms by which the plant regulates the symbiosis in response to its nutrient status. Plants possess many classes of Pi transport proteins, including a unique clade (Pht1, subfamily I), members of which are expressed only in the AM symbiosis. Here, we show that MtPT4, a Medicago truncatula member of subfamily I, is essential for the acquisition of Pi delivered by the AM fungus. However, more significantly, MtPT4 function is critical for AM symbiosis. Loss of MtPT4 function leads to premature death of the arbuscules; the fungus is unable to proliferate within the root...

The genome of the intracellular bacterium of the coastal bivalve, Solemya velum: a blueprint for thriving in and out of symbiosis

Dmytrenko, Oleg; Russell, Shelbi L; Loo, Wesley T; Fontanez, Kristina M; Liao, Li; Roeselers, Guus; Sharma, Raghav; Stewart, Frank J; Newton, Irene LG; Woyke, Tanja; Wu, Dongying; Lang, Jenna Morgan; Eisen, Jonathan A; Cavanaugh, Colleen M
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
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37.03%
Background: Symbioses between chemoautotrophic bacteria and marine invertebrates are rare examples of living systems that are virtually independent of photosynthetic primary production. These associations have evolved multiple times in marine habitats, such as deep-sea hydrothermal vents and reducing sediments, characterized by steep gradients of oxygen and reduced chemicals. Due to difficulties associated with maintaining these symbioses in the laboratory and culturing the symbiotic bacteria, studies of chemosynthetic symbioses rely heavily on culture independent methods. The symbiosis between the coastal bivalve, Solemya velum, and its intracellular symbiont is a model for chemosynthetic symbioses given its accessibility in intertidal environments and the ability to maintain it under laboratory conditions. To better understand this symbiosis, the genome of the S. velum endosymbiont was sequenced. Results: Relative to the genomes of obligate symbiotic bacteria, which commonly undergo erosion and reduction, the S. velum symbiont genome was large (2.7 Mb), GC-rich (51%), and contained a large number (78) of mobile genetic elements. Comparative genomics identified sets of genes specific to the chemosynthetic lifestyle and necessary to sustain the symbiosis. In addition...

Industrial symbiosis and the successional city : adapting exchange networks to energy constraints

Terway, Timothy M. (Timothy Michael)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 142 p.
ENG
Relevância na Pesquisa
27.25%
Industrial ecology offers models for hybridizing technology and natural processes, human desires and the capacities of ecosystems in an effort to reconcile the expanding conflicts among them. Industrial symbiosis applies this thinking to the scale of the city and its supporting industrial operations. Case studies of industrial symbiosis, which is the changing of linear, open-loop production to closed-loop systems through the reuse and exchange of waste materials, energy, and knowledge, showcase advantages in waste and energy use reduction within the United States. What are the major limits holding back the widespread development of industrial symbiosis in this country and how can they be overcome? Secondly, what tools can foster its large-scale implementation once the constraints are overcome? Methodologically, the successful study of the future capacity of industrial symbiosis within the American context must address the future consequences of resources that are no longer cheap nor abundant, as well as the current state of their production, distribution, and consumption.; (cont.) The major constraints facing industrial symbiosis in America are: current extremely high subsidies in transport and resource costs, low symbiosis visibility...

Industrial Symbiosis for Very Large Scale Photovoltaic Manufacturing

Pearce, Joshua M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica Formato: 526183 bytes; application/pdf
EN
Relevância na Pesquisa
36.8%
In order to stabilize the global climate the world’s governments must make significant commitments to drastically reduce global greenhouse gas (GHG) emissions. One of the most promising methods of curbing GHG emissions is a world transition from fossil fuels to renewable sources of energy. Solar photovoltaic (PV) cells offer a technically sustainable solution to the projected enormous future energy demands. This article explores utilizing industrial symbiosis to obtain economies of scale and increased manufacturing efficiencies for solar photovoltaic cells in order for solar electricity to compete economically with fossil fuel-fired electricity. The state of PV manufacturing, the market and the effects of scale on both are reviewed. Government policies necessary to construct a multi-gigaWatt PV factory and complimentary policies to protect existing solar companies are outlined and the technical requirements for a symbiotic industrial system are explored to increase the manufacturing efficiency while improving the environmental impact of PV. The results of the analysis show that an 8-factory industrial symbiotic system can be viewed as a medium-term investment by any government, which will not only obtain direct financial return, but also an improved global environment. The technical concepts and policy limitations to this approach were analyzed and it was found that symbiotic growth will help to mitigate many of the limitations of PV and is likely to catalyze mass manufacturing of PV by transparently demonstrating that large scale PV manufacturing is technically feasible and reaches an enormous untapped market for PV with low costs.

PROTEOMIC ANALYSIS OF WOLBACHIA SYMBIOSIS WITHIN THE DROSOPHILA OVARY

Perez, Ricardo
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Relevância na Pesquisa
36.8%
Wolbachia pipientis are bacterial endosymbionts carried by millions of invertebrate species, including ~40% of insect species and some filarial nematodes. In insects, basic Wolbachia research has potential applications in controlling vector borne disease. Conversely, Wolbachia of filarial nematodes are causative agents of neglected tropical diseases such as lymphatic filariasis and African river blindness. However, remarkably little is known about how Wolbachia interact with their hosts at the molecular level. Understanding this is important to inform the basis for symbiosis and help prevent human disease. I used a high-throughput proteomics approach to study how Drosophila host cells are modified by Wolbachia infection. This analysis identified 23 Drosophila proteins that significantly changed in amount as a result of Wolbachia infection. A subset of differentially abundant host proteins were consistent with Wolbachia-associated phenotypes reported previously. This study also provides the first ever discovery-based evidence for a Wolbachia-associated change in maternal germline histone loads, which has possible implications in Rescue of a common Wolbachia-induced reproductive manipulation known as Cytoplasmic Incompatibility.

Evolutionary costs and benefits of a newly discovered symbiosis between the social amoeba Dictyostelium and bacteria

Brock, Debra Lynn Adams
Fonte: Universidade Rice Publicador: Universidade Rice
ENG
Relevância na Pesquisa
37.03%
Recent work has shown that microorganisms are surprisingly like animals in having sophisticated behaviours such as cooperation, communication, and recognition, as well as many kinds of symbioses. Here we show first that the social amoeba Dictyostelium discoideum has a primitive farming symbiosis that includes dispersal and prudent harvesting of the crop. About one-third of wild-collected clones engage in husbandry of bacteria. Instead of consuming all bacteria in their patch, they stop feeding early and incorporate bacteria into their fruiting bodies. They then carry bacteria during spore dispersal and can seed a new food crop, which is a major advantage if edible bacteria are lacking at the new site. However, if they arrive at sites already containing appropriate bacteria, the costs of early feeding cessation are not compensated, which may account for the dichotomous nature of this farming symbiosis. We also observed farmer Dictyostelium discoideum clones carry bacteria that they do not use as food. We hypothesized that these bacteria may play a defensive role against other D. discoideum clones. In our second study, we investigated the impact of these bacteria-carrying farmers on non-farming D. discoideum clones. We found that the presence of farming clones reduces spore production in non-farmers. Furthermore...

Full Establishment of Arbuscular Mycorrhizal Symbiosis in Rice Occurs Independently of Enzymatic Jasmonate Biosynthesis

Gutjahr, Caroline; Siegler, Heike; Haga, Ken; Iino, Moritoshi; Paszkowski, Uta
Fonte: PLOS Publicador: PLOS
Tipo: Article; published version
EN
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36.8%
This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/ 10.1371/journal.pone.0123422; Development of the mutualistic arbuscular mycorrhiza (AM) symbiosis between most land plants and fungi of the Glomeromycota is regulated by phytohormones. The role of jasmonate (JA) in AM colonization has been investigated in the dicotyledons Medicago truncatula, tomato and Nicotiana attenuata and contradicting results have been obtained with respect to a neutral, promotive or inhibitory effect of JA on AM colonization. Furthermore, it is currently unknown whether JA plays a role in AM colonization of monocotyledonous roots. Therefore we examined whether JA biosynthesis is required for AM colonization of the monocot rice. To this end we employed the rice mutant constitutive photomorphogenesis 2 (cpm2), which is deficient in JA biosynthesis. Through a time course experiment the amount and morphology of fungal colonization did not differ between wild-type and cpm2 roots. Furthermore, no significant difference in the expression of AM marker genes was detected between wild type and cpm2. However, treatment of wild-type roots with 50 ?M JA lead to a decrease of AM colonization and this was correlated with induction of the defense gene PR4. These results indicate that JA is not required for AM colonization of rice but high levels of JA in the roots suppress AM development likely through the induction of defense.; CG was supported by a PhD fellowship of the German National Merit Foundation (Studienstiftung des Deutschen Volkes); http://www.studienstiftung.de/ and the Roche Foundation (Switzerland). Research in the UP laboratory was supported by the SNF 'professeur boursier' grants PP00A-110874 and PP00P3-130704; http://www.snf.ch/en/Pages/default.aspx. The funders had no role in study design...

The Molecular Biology of Lichen Symbiosis and Development

Joneson, Suzanne
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação Formato: 3043183 bytes; application/pdf
Publicado em //2009 EN_US
Relevância na Pesquisa
37.29%

Lichen-forming fungi employ a successful mode of nutrition as symbiotic partners with green algae and/or cyanobacteria (the photobiont). Nearly one fifth of all known fungi are obligate lichen formers, yet we know little of how they find compatible partners and establish long-lived symbiotic relationships. The combined growth of these symbionts forms a body (thallus) with emergent properties unlike either of the symbionts individually grown. Based on other well-studied eukaryotic systems, the development of a lichen thallus must rely upon the successful identification and collaboration of these two very different organisms. Identifying the molecular basis of microbe recognition and interactions remains one of the greatest challenges in studying symbiotic systems.

In this thesis, I determine the stage in which to begin looking for lichen symbiosis specific genes, and then examine mycobiont and photobiont genes that, when compared to the aposymbiotic state, are upregulated in the symbiotic state. Using the symbiosis between the mycobiont Cladonia grayi and the photobiont Asterochloris sp., as well as scanning electron microscopy observations of the earliest stages of contact between C. grayi and Asterochloris sp....

GmZIPI encodes a symbiosis specific zinc transporter in soybean

Moreau, Sophie; Thomson, Rowena M; Kaiser, B; Trevaskis, Ben; Guerinot, M; Udvardi, Michael; Puppo, Alain J
Fonte: American Society for Biochemistry and Molecular Biology Inc Publicador: American Society for Biochemistry and Molecular Biology Inc
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
36.8%
The importance of zinc in organisms is clearly established, and mechanisms involved in zinc acquisition by plants have recently received increased interest. In this report, the identification, characterization and location of GmZIP1, the first soybean member of the ZIP family of metal transporters, are described. GmZIP1 was found to possess eight putative transmembrane domains together with a histidine-rich extra-membrane loop. By functional complementation of zrt1zrt2 yeast cells no longer able to take up zinc, GmZIP1 was found to be highly selective for zinc, with an estimated Km value of 13.8 μM. Cadmium was the only other metal tested able to inhibit zinc uptake in yeast. An antibody raised against GmZIP1 specifically localized the protein to the peribacteroid membrane, an endosymbiotic membrane in nodules resulting from the interaction of the plant with its microsymbiont. The specific expression of GmZIP1 in nodules was confirmed by Northern blot, with no expression in roots, stems, or leaves of nodulated soybean plants. Antibodies to GmZIP1 inhibited zinc uptake by symbiosomes, indicating that at least some of the zinc uptake observed in isolated symbiosomes could be attributed to GmZIP1. The orientation of the protein in the membrane and its possible role in the symbiosis are discussed.