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Sample records for promoting industrial symbiosis

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

  2. Network analysis of eight industrial symbiosis systems

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Zheng, Hongmei; Shi, Han; Yu, Xiangyi; Liu, Gengyuan; Su, Meirong; Li, Yating; Chai, Yingying

    2016-06-01

    Industrial symbiosis is the quintessential characteristic of an eco-industrial park. To divide parks into different types, previous studies mostly focused on qualitative judgments, and failed to use metrics to conduct quantitative research on the internal structural or functional characteristics of a park. To analyze a park's structural attributes, a range of metrics from network analysis have been applied, but few researchers have compared two or more symbioses using multiple metrics. In this study, we used two metrics (density and network degree centralization) to compare the degrees of completeness and dependence of eight diverse but representative industrial symbiosis networks. Through the combination of the two metrics, we divided the networks into three types: weak completeness, and two forms of strong completeness, namely "anchor tenant" mutualism and "equality-oriented" mutualism. The results showed that the networks with a weak degree of completeness were sparse and had few connections among nodes; for "anchor tenant" mutualism, the degree of completeness was relatively high, but the affiliated members were too dependent on core members; and the members in "equality-oriented" mutualism had equal roles, with diverse and flexible symbiotic paths. These results revealed some of the systems' internal structure and how different structures influenced the exchanges of materials, energy, and knowledge among members of a system, thereby providing insights into threats that may destabilize the network. Based on this analysis, we provide examples of the advantages and effectiveness of recent improvement projects in a typical Chinese eco-industrial park (Shandong Lubei).

  3. Academia-industry symbiosis in organic chemistry.

    PubMed

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

    2015-03-17

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

  4. Academia-industry symbiosis in organic chemistry.

    PubMed

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

    2015-03-17

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

  5. Academia–Industry Symbiosis in Organic Chemistry

    PubMed Central

    2015-01-01

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

  6. A review of industrial symbiosis research: theory and methodology

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Zheng, Hongmei; Chen, Bin; Su, Meirong; Liu, Gengyuan

    2015-03-01

    The theory, methodologies, and case studies in the field of industrial symbiosis have been developing for nearly 30 years. In this paper, we trace the development history of industrial symbiosis, and review its current theoretical and methodological bases, as well as trends in current research. Based on the research gaps that we identify, we provide suggestions to guide the future development of this approach to permit more comprehensive analyses. Our theoretical review includes key definitions, a classification system, and a description of the formation and development mechanisms. We discuss methodological studies from the perspective of individual industrial metabolic processes and network analysis. Analyzing specific metabolic processes can help to characterize the exchanges of materials and energy, and to reveal the ecological performance and economic benefits of the symbiosis. Network analysis methods are increasingly being used to analyze both the structural and functional characteristics of a system. Our suggestions for future research focus on three aspects: how to quantitatively classify industrial symbiosis systems, monitor the dynamics of a developing industrial symbiosis system, and analyze its internal attributes more deeply.

  7. Understanding resilience in industrial symbiosis networks: insights from network analysis.

    PubMed

    Chopra, Shauhrat S; Khanna, Vikas

    2014-08-01

    Industrial symbiotic networks are based on the principles of ecological systems where waste equals food, to develop synergistic networks. For example, industrial symbiosis (IS) at Kalundborg, Denmark, creates an exchange network of waste, water, and energy among companies based on contractual dependency. Since most of the industrial symbiotic networks are based on ad-hoc opportunities rather than strategic planning, gaining insight into disruptive scenarios is pivotal for understanding the balance of resilience and sustainability and developing heuristics for designing resilient IS networks. The present work focuses on understanding resilience as an emergent property of an IS network via a network-based approach with application to the Kalundborg Industrial Symbiosis (KIS). Results from network metrics and simulated disruptive scenarios reveal Asnaes power plant as the most critical node in the system. We also observe a decrease in the vulnerability of nodes and reduction in single points of failure in the system, suggesting an increase in the overall resilience of the KIS system from 1960 to 2010. Based on our findings, we recommend design strategies, such as increasing diversity, redundancy, and multi-functionality to ensure flexibility and plasticity, to develop resilient and sustainable industrial symbiotic networks.

  8. Commensal bacteria direct selective cargo sorting to promote symbiosis.

    PubMed

    Zhang, Qin; Pan, Ying; Yan, Ruiqing; Zeng, Benhua; Wang, Haifang; Zhang, Xinwen; Li, Wenxia; Wei, Hong; Liu, Zhihua

    2015-09-01

    Mucosal immunity protects a host from intestinal inflammation and infection and is profoundly influenced by symbiotic bacteria. Here we report that in mice symbiotic bacteria directed selective cargo sorting in Paneth cells to promote symbiosis through Nod2, a cytosolic bacterial sensor, and the multifunctional protein kinase LRRK2, both encoded by inflammatory bowel disease (IBD)-associated genes. Commensals recruited Nod2 onto lysozyme-containing dense core vesicles (DCVs), which was required for DCV localization of LRRK2 and a small GTPase, Rab2a. Deficiency of Nod2, LRRK2 or Rab2a or depletion of commensals resulted in lysosomal degradation of lysozyme. Thus, commensal bacteria and host factors orchestrate the lysozyme-sorting process to protect the host from enteric infection, implicating Paneth cell dysfunction in IBD pathogenesis.

  9. Emergy-based assessment on industrial symbiosis: a case of Shenyang Economic and Technological Development Zone.

    PubMed

    Geng, Yong; Liu, Zuoxi; Xue, Bing; Dong, Huijuan; Fujita, Tsuyoshi; Chiu, Anthony

    2014-12-01

    Industrial symbiosis is the sharing of services, utility, and by-product resources among industries. This is usually made in order to add value, reduce costs, and improve the environment, and therefore has been taken as an effective approach for developing an eco-industrial park, improving resource efficiency, and reducing pollutant emission. Most conventional evaluation approaches ignored the contribution of natural ecosystem to the development of industrial symbiosis and cannot reveal the interrelations between economic development and environmental protection, leading to a need of an innovative evaluation method. Under such a circumstance, we present an emergy analysis-based evaluation method by employing a case study at Shenyang Economic and Technological Development Zone (SETDZ). Specific emergy indicators on industrial symbiosis, including emergy savings and emdollar value of total emergy savings, were developed so that the holistic picture of industrial symbiosis can be presented. Research results show that nonrenewable inputs, imported resource inputs, and associated services could be saved by 89.3, 32.51, and 15.7 %, and the ratio of emergy savings to emergy of the total energy used would be about 25.58 %, and the ratio of the emdollar value of total emergy savings to the total gross regional product (GRP) of SETDZ would be 34.38 % through the implementation of industrial symbiosis. In general, research results indicate that industrial symbiosis could effectively reduce material and energy consumption and improve the overall eco-efficiency. Such a method can provide policy insights to industrial park managers so that they can raise appropriate strategies on developing eco-industrial parks. Useful strategies include identifying more potential industrial symbiosis opportunities, optimizing energy structure, increasing industrial efficiency, recovering local ecosystems, and improving public and industrial awareness of eco-industrial park policies.

  10. Emergy-based assessment on industrial symbiosis: a case of Shenyang Economic and Technological Development Zone.

    PubMed

    Geng, Yong; Liu, Zuoxi; Xue, Bing; Dong, Huijuan; Fujita, Tsuyoshi; Chiu, Anthony

    2014-12-01

    Industrial symbiosis is the sharing of services, utility, and by-product resources among industries. This is usually made in order to add value, reduce costs, and improve the environment, and therefore has been taken as an effective approach for developing an eco-industrial park, improving resource efficiency, and reducing pollutant emission. Most conventional evaluation approaches ignored the contribution of natural ecosystem to the development of industrial symbiosis and cannot reveal the interrelations between economic development and environmental protection, leading to a need of an innovative evaluation method. Under such a circumstance, we present an emergy analysis-based evaluation method by employing a case study at Shenyang Economic and Technological Development Zone (SETDZ). Specific emergy indicators on industrial symbiosis, including emergy savings and emdollar value of total emergy savings, were developed so that the holistic picture of industrial symbiosis can be presented. Research results show that nonrenewable inputs, imported resource inputs, and associated services could be saved by 89.3, 32.51, and 15.7 %, and the ratio of emergy savings to emergy of the total energy used would be about 25.58 %, and the ratio of the emdollar value of total emergy savings to the total gross regional product (GRP) of SETDZ would be 34.38 % through the implementation of industrial symbiosis. In general, research results indicate that industrial symbiosis could effectively reduce material and energy consumption and improve the overall eco-efficiency. Such a method can provide policy insights to industrial park managers so that they can raise appropriate strategies on developing eco-industrial parks. Useful strategies include identifying more potential industrial symbiosis opportunities, optimizing energy structure, increasing industrial efficiency, recovering local ecosystems, and improving public and industrial awareness of eco-industrial park policies. PMID

  11. Design for sustainability of industrial symbiosis based on emergy and multi-objective particle swarm optimization.

    PubMed

    Ren, Jingzheng; Liang, Hanwei; Dong, Liang; Sun, Lu; Gao, Zhiqiu

    2016-08-15

    Industrial symbiosis provides novel and practical pathway to the design for the sustainability. Decision support tool for its verification is necessary for practitioners and policy makers, while to date, quantitative research is limited. The objective of this work is to present an innovative approach for supporting decision-making in the design for the sustainability with the implementation of industrial symbiosis in chemical complex. Through incorporating the emergy theory, the model is formulated as a multi-objective approach that can optimize both the economic benefit and sustainable performance of the integrated industrial system. A set of emergy based evaluation index are designed. Multi-objective Particle Swarm Algorithm is proposed to solve the model, and the decision-makers are allowed to choose the suitable solutions form the Pareto solutions. An illustrative case has been studied by the proposed method, a few of compromises between high profitability and high sustainability can be obtained for the decision-makers/stakeholders to make decision.

  12. Beyond the Boundary: Science, Industry, and Managing Symbiosis

    ERIC Educational Resources Information Center

    Hansen, Birgitte Gorm

    2011-01-01

    Whether celebratory or critical, STS research on science-industry relations has focused on the blurring of boundaries and hybridization of codes and practices. However, the vocabulary of boundary and hybrid tends to reify science and industry as separate in the attempt to map their relation. Drawing on interviews with the head of a research center…

  13. Methods for assessing the energy-saving efficiency of industrial symbiosis in industrial parks.

    PubMed

    Li, Wenfeng; Cui, Zhaojie; Han, Feng

    2015-01-01

    The available energy resources are being depleted worldwide. Industrial symbiosis (IS) provides a promising approach for increasing the efficiency of energy utilization, with numerous studies reporting the superiority of this technology. However, studies quantifying the energy-saving efficiency of IS remain insufficient. This paper proposes an index system for the quantitative evaluation of the energy-saving efficiency of IS. Both energy-saving and financial indexes were selected, the former include the IS energy-saving index, the contribution rate of energy saved through IS, fractional energy savings, and cut rate of energy consumption per total output value; and the latter include the IS investment payback period, IS input-output ratio, net present value (NPV), and internal rate of return (IRR) of IS. The proposed methods were applied to a case study on the XF Industrial Park (XF IP), in the city of Liaocheng in Shandong Province of China. Three energy-saving channels using IS were found in the XF IP: (a) utilizing the energy of high-temperature materials among industrial processes, (b) recovering waste heat and steam between different processes, and (c) saving energy by sharing infrastructures. The results showed that the energy efficiency index of IS was 0.326, accounting for 34.6% of the comprehensive energy-saving index in 2011, and the fractional energy-savings were 12.42%. The index of energy consumption per total industrial output value varied from 90.9 tce/MRMB to 51.6 tce/MRMB. Thus, the cut rate of energy consumption per total industrial output value was 43.42%. The average values of the IS input-output ratio was 406.2 RMB/tce, 57.2% lower than the price of standard coal. Static investment payback period in the XF IP was 8.5 months, indicating that the XF IP began to earn profit 8.5 months after the construction of all IS modes. The NVP and IRR of each IS mode in the XF IP were greater than zero, with average values equal to 1,789.96 MRMB and 140

  14. Methods for assessing the energy-saving efficiency of industrial symbiosis in industrial parks.

    PubMed

    Li, Wenfeng; Cui, Zhaojie; Han, Feng

    2015-01-01

    The available energy resources are being depleted worldwide. Industrial symbiosis (IS) provides a promising approach for increasing the efficiency of energy utilization, with numerous studies reporting the superiority of this technology. However, studies quantifying the energy-saving efficiency of IS remain insufficient. This paper proposes an index system for the quantitative evaluation of the energy-saving efficiency of IS. Both energy-saving and financial indexes were selected, the former include the IS energy-saving index, the contribution rate of energy saved through IS, fractional energy savings, and cut rate of energy consumption per total output value; and the latter include the IS investment payback period, IS input-output ratio, net present value (NPV), and internal rate of return (IRR) of IS. The proposed methods were applied to a case study on the XF Industrial Park (XF IP), in the city of Liaocheng in Shandong Province of China. Three energy-saving channels using IS were found in the XF IP: (a) utilizing the energy of high-temperature materials among industrial processes, (b) recovering waste heat and steam between different processes, and (c) saving energy by sharing infrastructures. The results showed that the energy efficiency index of IS was 0.326, accounting for 34.6% of the comprehensive energy-saving index in 2011, and the fractional energy-savings were 12.42%. The index of energy consumption per total industrial output value varied from 90.9 tce/MRMB to 51.6 tce/MRMB. Thus, the cut rate of energy consumption per total industrial output value was 43.42%. The average values of the IS input-output ratio was 406.2 RMB/tce, 57.2% lower than the price of standard coal. Static investment payback period in the XF IP was 8.5 months, indicating that the XF IP began to earn profit 8.5 months after the construction of all IS modes. The NVP and IRR of each IS mode in the XF IP were greater than zero, with average values equal to 1,789.96 MRMB and 140

  15. Industrial and urban symbiosis in Japan: analysis of the Eco-Town Program 1997-2006.

    PubMed

    Van Berkel, Rene; Fujita, Tsuyoshi; Hashimoto, Shizuka; Geng, Yong

    2009-03-01

    Japan's Eco-Town Program spearheaded in Japan the integration of Industrial Symbiosis and Urban Symbiosis, seeking to maximise the economic and environmental benefit from close geographic proximity of industrial and urban areas, through the use of previously discarded commercial, municipal and industrial waste materials in industrial applications. The program established 26 Eco-Towns around Japan. Approximately 1.65 billion USD was invested in 61 innovative recycling projects, with an average government subsidy of 36%. In addition at least 107 other recycling facilities have been constructed without government subsidy. 14 Eco-Towns primarily contributed to improving industry's productivity, whilst 10 Eco-Towns primarily contributed to improving environmental amenity. In 16 Eco-Towns the private sector was the most important actor supporting local government in the realisation of the Eco-Town, whilst in 9 Eco-Towns this was civil society. The availability of investment subsidies, the coming into force of ambitious recycling legislation with quantified, product-specific targets, access to the significant technological resources of the private sector, and widespread recognition of the urgency to act on environmental issues, all contributed to the success of the Eco-Town Program.

  16. Design for sustainability of industrial symbiosis based on emergy and multi-objective particle swarm optimization.

    PubMed

    Ren, Jingzheng; Liang, Hanwei; Dong, Liang; Sun, Lu; Gao, Zhiqiu

    2016-08-15

    Industrial symbiosis provides novel and practical pathway to the design for the sustainability. Decision support tool for its verification is necessary for practitioners and policy makers, while to date, quantitative research is limited. The objective of this work is to present an innovative approach for supporting decision-making in the design for the sustainability with the implementation of industrial symbiosis in chemical complex. Through incorporating the emergy theory, the model is formulated as a multi-objective approach that can optimize both the economic benefit and sustainable performance of the integrated industrial system. A set of emergy based evaluation index are designed. Multi-objective Particle Swarm Algorithm is proposed to solve the model, and the decision-makers are allowed to choose the suitable solutions form the Pareto solutions. An illustrative case has been studied by the proposed method, a few of compromises between high profitability and high sustainability can be obtained for the decision-makers/stakeholders to make decision. PMID:27110990

  17. Assessment of life cycle environmental benefits of an industrial symbiosis cluster in China.

    PubMed

    Yu, Fei; Han, Feng; Cui, Zhaojie

    2015-04-01

    Reusing industrial waste may have impressive potential environmental benefits, especially in terms of the total life cycle, and life cycle assessment (LCA) has been proved to be an effective method to evaluate industrial symbiosis (IS). Circular economy and IS have been developed for decades and have been successful in China. However, very few studies about the environmental benefit assessment of IS applied by LCA in China have been conducted. In the current article, LCA was used to evaluate the environmental benefits and costs of IS, compared with a no-IS scenario for four environmental impact categories. The results showed that four environmental benefits were avoided by the 11 symbiosis performances, namely, 41.6 thousand TJ of primary energy, 4.47 million t CO2e of greenhouse gasses, 19.7 thousand t SO2e of acidification, and 81.1 t PO4(3+)e of eutrophication. Among these IS performances, the comprehensive utilization of red mud produced the most visible benefit. The results also present that energy conservation was the distinctive feature of IS in China.

  18. Assessment of life cycle environmental benefits of an industrial symbiosis cluster in China.

    PubMed

    Yu, Fei; Han, Feng; Cui, Zhaojie

    2015-04-01

    Reusing industrial waste may have impressive potential environmental benefits, especially in terms of the total life cycle, and life cycle assessment (LCA) has been proved to be an effective method to evaluate industrial symbiosis (IS). Circular economy and IS have been developed for decades and have been successful in China. However, very few studies about the environmental benefit assessment of IS applied by LCA in China have been conducted. In the current article, LCA was used to evaluate the environmental benefits and costs of IS, compared with a no-IS scenario for four environmental impact categories. The results showed that four environmental benefits were avoided by the 11 symbiosis performances, namely, 41.6 thousand TJ of primary energy, 4.47 million t CO2e of greenhouse gasses, 19.7 thousand t SO2e of acidification, and 81.1 t PO4(3+)e of eutrophication. Among these IS performances, the comprehensive utilization of red mud produced the most visible benefit. The results also present that energy conservation was the distinctive feature of IS in China. PMID:25339529

  19. Colonization of root cells and plant growth promotion by Piriformospora indica occurs independently of plant common symbiosis genes

    PubMed Central

    Banhara, Aline; Ding, Yi; Kühner, Regina; Zuccaro, Alga; Parniske, Martin

    2015-01-01

    Arbuscular mycorrhiza (AM) fungi (Glomeromycota) form symbiosis with and deliver nutrients via the roots of most angiosperms. AM fungal hyphae are taken up by living root epidermal cells, a program which relies on a set of plant common symbiosis genes (CSGs). Plant root epidermal cells are also infected by the plant growth-promoting fungus Piriformospora indica (Basidiomycota), raising the question whether this interaction relies on the AM-related CSGs. Here we show that intracellular colonization of root cells and intracellular sporulation by P. indica occurred in CSG mutants of the legume Lotus japonicus and in Arabidopsis thaliana, which belongs to the Brassicaceae, a family that has lost the ability to form AM as well as a core set of CSGs. A. thaliana mutants of homologs of CSGs (HCSGs) interacted with P. indica similar to the wild-type. Moreover, increased biomass of A. thaliana evoked by P. indica was unaltered in HCSG mutants. We conclude that colonization and growth promotion by P. indica are independent of the CSGs and that AM fungi and P. indica exploit different host pathways for infection. PMID:26441999

  20. Medicago sativa--Sinorhizobium meliloti Symbiosis Promotes the Bioaccumulation of Zinc in Nodulated Roots.

    PubMed

    Zribi, Kais; Nouairi, Issam; Slama, Ines; Talbi-Zribi, Ons; Mhadhbi, Haythem

    2015-01-01

    In this study we investigated effects of Zn supply on germination, growth, inorganic solutes (Zn, Ca, Fe, and Mg) partitioning and nodulation of Medicago sativa This plant was cultivated with and without Zn (2 mM). Treatments were plants without (control) and with Zn tolerant strain (S532), Zn intolerant strain (S112) and 2 mM urea nitrogen fertilisation. Results showed that M. sativa germinates at rates of 50% at 2 mM Zn. For plants given nitrogen fertilisation, Zn increased plant biomass production. When grown with symbionts, Zn supply had no effect on nodulation. Moreover, plants with S112 showed a decrease of shoot and roots biomasses. However, in symbiosis with S532, an increase of roots biomass was observed. Plants in symbiosis with S. meliloti accumulated more Zn in their roots than nitrogen fertilised plants. Zn supply results in an increase of Ca concentration in roots of fertilised nitrogen plants. However, under Zn supply, Fe concentration decreased in roots and increased in nodules of plants with S112. Zn supply showed contrasting effects on Mg concentrations for plants with nitrogen fertilisation (increase) and plants with S112 (decrease). The capacity of M. sativa to accumulate Zn in their nodulated roots encouraged its use in phytostabilisation processes.

  1. Strategies for sustainable development of industrial park in Ulsan, South Korea--from spontaneous evolution to systematic expansion of industrial symbiosis.

    PubMed

    Park, Hung-Suck; Rene, Eldon R; Choi, Soo-Mi; Chiu, Anthony S F

    2008-04-01

    The Korea National Cleaner Production Center (KNCPC) affiliated to the Korea Institute of Industrial Technology (KITECH) has started a 15 year, 3-phase EIP master plan with the support of Ministry of Commerce, Industry, and Energy (MOCIE). A total of 6 industrial parks, including industrial parks in Ulsan city, known as the industrial capital of South Korea, are planning projects to find the feasibility of shifting existing industrial parks to eco-industrial parks. The basic survey shows that Ulsan industrial complex has been continuously evolving from conventional industrial complexes to eco-industrial parks by spontaneous industrial symbiosis. This paper describes the Korean national policies and the developmental activities of this vision to drive the global trend of innovation for converting the existing industrial parks to eco-industrial parks through inter-industry waste, energy, and material exchange in Ulsan Industrial complexes. In addition, the primary and supportive components of the Ulsan EIP pilot project, which will be implemented for 5 years is elaborated with its schedules and economic benefits.

  2. Schoolyard Symbiosis.

    ERIC Educational Resources Information Center

    Allard, David W.

    1996-01-01

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

  3. The Piriformospora indica effector PIIN_08944 promotes the mutualistic Sebacinalean symbiosis

    PubMed Central

    Akum, Fidele N.; Steinbrenner, Jens; Biedenkopf, Dagmar; Imani, Jafargholi; Kogel, Karl-Heinz

    2015-01-01

    Pathogenic and mutualistic microbes actively suppress plant defense by secreting effector proteins to manipulate the host responses for their own benefit. Current knowledge about fungal effectors has been mainly derived from biotrophic and hemibiotrophic plant pathogenic fungi and oomycetes with restricted host range. We studied colonization strategies of the root endophytic basidiomycete Piriformospora indica that colonizes a wide range of plant species thereby establishing long-term mutualistic relationships. The release of P. indica’s genome helped to identify hundreds of genes coding for candidate effectors and provides an opportunity to investigate the role of those proteins in a mutualistic symbiosis. We demonstrate that the candidate effector PIIN_08944 plays a crucial role during fungal colonization of Arabidopsis thaliana roots. PIIN_08944 expression was detected during chlamydospore germination, and fungal deletion mutants (PiΔ08944) showed delayed root colonization. Constitutive over-expression of PIIN_08944 in Arabidopsis rescued the delayed colonization phenotype of the deletion mutant. PIIN_08944-expressing Arabidopsis showed a reduced expression of flg22-induced marker genes of pattern-triggered immunity (PTI) and the salicylic acid (SA) defense pathway, and expression of PIIN_08944 in barley reduced the burst of reactive oxygen species (ROS) triggered by flg22 and chitin. These data suggest that PIIN_08944 contributes to root colonization by P. indica by interfering with SA-mediated basal immune responses of the host plant. Consistent with this, PIIN_08944-expressing Arabidopsis also supported the growth of the biotrophic oomycete Hyaloperonospora arabidopsidis while growth of the necrotrophic fungi Botrytis cinerea on Arabidopsis and Fusarium graminearum on barley was not affected. PMID:26579156

  4. The Piriformospora indica effector PIIN_08944 promotes the mutualistic Sebacinalean symbiosis.

    PubMed

    Akum, Fidele N; Steinbrenner, Jens; Biedenkopf, Dagmar; Imani, Jafargholi; Kogel, Karl-Heinz

    2015-01-01

    Pathogenic and mutualistic microbes actively suppress plant defense by secreting effector proteins to manipulate the host responses for their own benefit. Current knowledge about fungal effectors has been mainly derived from biotrophic and hemibiotrophic plant pathogenic fungi and oomycetes with restricted host range. We studied colonization strategies of the root endophytic basidiomycete Piriformospora indica that colonizes a wide range of plant species thereby establishing long-term mutualistic relationships. The release of P. indica's genome helped to identify hundreds of genes coding for candidate effectors and provides an opportunity to investigate the role of those proteins in a mutualistic symbiosis. We demonstrate that the candidate effector PIIN_08944 plays a crucial role during fungal colonization of Arabidopsis thaliana roots. PIIN_08944 expression was detected during chlamydospore germination, and fungal deletion mutants (PiΔ08944) showed delayed root colonization. Constitutive over-expression of PIIN_08944 in Arabidopsis rescued the delayed colonization phenotype of the deletion mutant. PIIN_08944-expressing Arabidopsis showed a reduced expression of flg22-induced marker genes of pattern-triggered immunity (PTI) and the salicylic acid (SA) defense pathway, and expression of PIIN_08944 in barley reduced the burst of reactive oxygen species (ROS) triggered by flg22 and chitin. These data suggest that PIIN_08944 contributes to root colonization by P. indica by interfering with SA-mediated basal immune responses of the host plant. Consistent with this, PIIN_08944-expressing Arabidopsis also supported the growth of the biotrophic oomycete Hyaloperonospora arabidopsidis while growth of the necrotrophic fungi Botrytis cinerea on Arabidopsis and Fusarium graminearum on barley was not affected. PMID:26579156

  5. Teaching Symbiosis.

    ERIC Educational Resources Information Center

    Harper, G. H.

    1985-01-01

    Argues that the meaning of the word "symbiosis" be standardized and that it should be used in a broad sense. Also criticizes the orthodox teaching of general principles in this subject and recommends that priority be given to continuity, intimacy, and associated adaptations, rather than to the harm/benefit relationship. (Author/JN)

  6. AEC to Referee, Not Promote, Industry.

    PubMed

    1971-10-29

    A major turnabout in the attitude of the Atomic Energy Commission toward the nuclear power industry was signaled last week by the ntew AEC chairman James R. Schlesinger. With patrician froideur, Schlesinger informed a mass gathering of the nuclear power industry at Bal Harbour, Florida, that from henceforth the AEC woLuld act as the referee of nuclear power, not its promoter. Saying he would dispense with the "anecdotes and clumsy jests" customary on such occasions, Schlesinger served notice on the nuclear banqueters that their cozy relationship with the AEC was at an end. The industry should not expect the AEC to fight its battles: it should take its own case to the public-as the Sierra Club does. Nor did the AEC intend to bend the rules in industry's favor. "We have had a fair amount of advice on how to evade the clear mandate of the federal courts. It is advice we did not think proper to accept," Schlesinger said. Even on matters of engineering quality, the diners were told they knew full well they had "reason to blush." Roused out of any postprandial euphoria by this glacial disdain, the industry representatives heard the new chairman announce the following radical upheavals in official AEC philosophy.

  7. Heavy metal stress in alders: Tolerance and vulnerability of the actinorhizal symbiosis.

    PubMed

    Bélanger, Pier-Anne; Bellenger, Jean-Philippe; Roy, Sébastien

    2015-11-01

    Alders have already demonstrated their potential for the revegetation of both mining and industrial sites. These actinorhizal trees and shrubs and the actinobacteria Frankia associate in a nitrogen-fixing symbiosis which could however be negatively affected by the presence of heavy metals, and accumulate them. In our hydroponic assay with black alders, quantification of the roots and shoots metal concentrations showed that, in the absence of stress, symbiosis increases Mo and Ni root content and simultaneously decreases Mo shoot content. Interestingly, the Mo shoot content also decreases in the presence of Ni, Cu, Pb, Zn and Cd for symbiotic alders. In symbiotic alders, Pb shoot translocation was promoted in presence of Pb. On the other hand, Cd exclusion in symbiotic root tissues was observed with Pb and Cd. In the presence of symbiosis, only Cd and Pb showed translocation into aerial tissues when present in the nutrient solution. Moreover, the translocation of Ni to shoot was prevented by symbiosis in the presence of Cd, Ni and Pb. The hydroponic experiment demonstrated that alders benefit from the symbiosis, producing more biomass (total, root and shoot) than non nodulated alders in control condition, and in the presence of metals (Cu, Ni, Zn, Pb and Cd). Heavy metals did not reduce the nodule numbers (SNN), but the presence of Zn or Cd did reduce nodule allocation. Our study suggests that the Frankia-alder symbiosis is a promising (and a compatible) plant-microorganism association for the revegetation of contaminated sites, with minimal risk of metal dispersion.

  8. Cell Biology of Cnidarian-Dinoflagellate Symbiosis

    PubMed Central

    Allemand, Denis; Weis, Virginia M.

    2012-01-01

    Summary: The symbiosis between cnidarians (e.g., corals or sea anemones) and intracellular dinoflagellate algae of the genus Symbiodinium is of immense ecological importance. In particular, this symbiosis promotes the growth and survival of reef corals in nutrient-poor tropical waters; indeed, coral reefs could not exist without this symbiosis. However, our fundamental understanding of the cnidarian-dinoflagellate symbiosis and of its links to coral calcification remains poor. Here we review what we currently know about the cell biology of cnidarian-dinoflagellate symbiosis. In doing so, we aim to refocus attention on fundamental cellular aspects that have been somewhat neglected since the early to mid-1980s, when a more ecological approach began to dominate. We review the four major processes that we believe underlie the various phases of establishment and persistence in the cnidarian/coral-dinoflagellate symbiosis: (i) recognition and phagocytosis, (ii) regulation of host-symbiont biomass, (iii) metabolic exchange and nutrient trafficking, and (iv) calcification. Where appropriate, we draw upon examples from a range of cnidarian-alga symbioses, including the symbiosis between green Hydra and its intracellular chlorophyte symbiont, which has considerable potential to inform our understanding of the cnidarian-dinoflagellate symbiosis. Ultimately, we provide a comprehensive overview of the history of the field, its current status, and where it should be going in the future. PMID:22688813

  9. Department of Industrial Health and Saftey Promotion: Curriculum Plan.

    ERIC Educational Resources Information Center

    Brody, Carmen

    The industrial health and safety promotion curriculum described in this paper is intended for an industrial manufacturing plant employing approximately 10,000 people. The paper begins by describing the plant and the workers for which the curriculum was designed. Next, a rationale for having a Department of Industrial Health and Safety program…

  10. How Symbiosis Creates Diversity

    ERIC Educational Resources Information Center

    Lord, Joshua

    2010-01-01

    Diversity in habitats on Earth is astounding--whether on land or in the sea--and this is in part due to symbiosis. The lesson described in this article helps students understand how symbiosis affects different organisms through a fun and engaging game where they match hosts and symbionts based on their respective needs. This 45-minute lesson is…

  11. [Promoting research from the viewpoint of industry].

    PubMed

    Specker, M

    1997-01-01

    Industry sponsors medical research in the fields of pharmaceutical products, diagnostics, medical technology, medical equipment, clinical nutrition and information systems. In pharmaceutical research, the companies of VFA invested a total of DM 4.3 billion in 1995, that means 18% of the turnover. DM 1.4 billion were spent mainly on clinical research studies. Beyond this, industry shares the costs of academic research institutes and gives support through its foundations. The decreasing number of domestic clinical studies, that German clinics complain about, is caused by organisational and administrative deficiencies, leading to major economic disadvantages. Recommendations of how to improve the situation exist and must be implemented.

  12. Heavy metal stress in alders: Tolerance and vulnerability of the actinorhizal symbiosis.

    PubMed

    Bélanger, Pier-Anne; Bellenger, Jean-Philippe; Roy, Sébastien

    2015-11-01

    Alders have already demonstrated their potential for the revegetation of both mining and industrial sites. These actinorhizal trees and shrubs and the actinobacteria Frankia associate in a nitrogen-fixing symbiosis which could however be negatively affected by the presence of heavy metals, and accumulate them. In our hydroponic assay with black alders, quantification of the roots and shoots metal concentrations showed that, in the absence of stress, symbiosis increases Mo and Ni root content and simultaneously decreases Mo shoot content. Interestingly, the Mo shoot content also decreases in the presence of Ni, Cu, Pb, Zn and Cd for symbiotic alders. In symbiotic alders, Pb shoot translocation was promoted in presence of Pb. On the other hand, Cd exclusion in symbiotic root tissues was observed with Pb and Cd. In the presence of symbiosis, only Cd and Pb showed translocation into aerial tissues when present in the nutrient solution. Moreover, the translocation of Ni to shoot was prevented by symbiosis in the presence of Cd, Ni and Pb. The hydroponic experiment demonstrated that alders benefit from the symbiosis, producing more biomass (total, root and shoot) than non nodulated alders in control condition, and in the presence of metals (Cu, Ni, Zn, Pb and Cd). Heavy metals did not reduce the nodule numbers (SNN), but the presence of Zn or Cd did reduce nodule allocation. Our study suggests that the Frankia-alder symbiosis is a promising (and a compatible) plant-microorganism association for the revegetation of contaminated sites, with minimal risk of metal dispersion. PMID:26091871

  13. 78 FR 24152 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order; Request...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-24

    ... Agricultural Marketing Service Softwood Lumber Research, Promotion, Consumer Education and Industry Information..., Promotion, Consumer Education and Industry Information Order (Order). DATES: Comments must be received by... INFORMATION: Title: Softwood Lumber Research, Promotion, Consumer Education and Industry Information...

  14. Tobacco related bar promotions: insights from tobacco industry documents

    PubMed Central

    Katz, S; Lavack, A

    2002-01-01

    Design: Over 2000 tobacco industry documents available as a result of the Master Settlement Agreement were reviewed on the internet at several key web sites using keyword searches that included "bar", "night", "pub", "party", and "club". The majority of the documents deal with the US market, with a minor emphasis on Canadian and overseas markets. Results: The documents indicate that bar promotions are important for creating and maintaining brand image, and are generally targeted at a young adult audience. Several measures of the success of these promotions are used, including number of individuals exposed to the promotion, number of promotional items given away, and increased sales of a particular brand during and after the promotion. Conclusion: Bar promotions position cigarettes as being part of a glamorous lifestyle that includes attendance at nightclubs and bars, and appear to be highly successful in increasing sales of particular brands. PMID:11893819

  15. Bibliographies on health promotion programs for business and industry.

    PubMed

    Martin, F; Dandoy, S; Kirkman-Liff, B; Chaconas, S

    1982-01-01

    Health promotion programs have been developing at a rapid pace throughout the United States. Business and industry have been major targets for and supporters of these new ventures. This intense interest in health promotion programs has produced a need for a systematic review of past experience. The Center for Health Services Administration at Arizona State University prepared two comprehensive bibliographies of references on occupational health promotion programs. The annotated bibliography includes ninety references that were deemed most relevant to the subject at the time the searches were made in Spring of 1982. The second bibliography, which is not annotated, is supplemental and provides eighty-eight additional related references.

  16. Tobacco point-of-purchase promotion: examining tobacco industry documents.

    PubMed

    Lavack, Anne M; Toth, Graham

    2006-10-01

    In the face of increasing media restrictions around the world, point-of-purchase promotion (also called point-of-sale merchandising, and frequently abbreviated as POP or POS) is now one of the most important tools that tobacco companies have for promoting tobacco products. Using tobacco industry documents, this paper demonstrates that tobacco companies have used point-of-purchase promotion in response to real or anticipated advertising restrictions. Their goal was to secure dominance in the retail setting, and this was achieved through well-trained sales representatives who offered contracts for promotional incentive programmes to retailers, which included the use of point-of-sale displays and merchandising fixtures. Audit programmes played an important role in ensuring contract enforcement and compliance with a variety of tobacco company incentive programmes. Tobacco companies celebrated their merchandising successes, in recognition of the stiff competition that existed among tobacco companies for valuable retail display space. PMID:16998172

  17. Symbiosis-mediated outbreaks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Symbiosis simply means "living together" and in its narrowest form can mean two species deriving mutual benefit from the association. Recent studies have made evident that insect associations with microorganisms can range the gamut from casual associations to obligate or context-dependent mutualisms...

  18. Survival through Symbiosis.

    ERIC Educational Resources Information Center

    Abdi, S. Wali

    1992-01-01

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

  19. Chinese Tobacco Industry Promotional Activity on the Microblog Weibo

    PubMed Central

    Wang, Fan; Zheng, Pinpin; Yang, Dongyun; Freeman, Becky; Fu, Hua; Chapman, Simon

    2014-01-01

    Background Although China ratified the WHO Framework Convention on Tobacco Control [FCTC] in 2005, the partial ban on tobacco advertising does not cover the internet. Weibo is one of the most important social media channels in China, using a format similar to its global counterpart, Twitter. The Weibo homepage is a platform to present products, brands and corporate culture. There is great potential for the tobacco industry to exploit Weibo to promote products. Methods Seven tobacco industry Weibo accounts that each had more than 5000 fans were selected to examine the content of Weibos established by tobacco companies or their advertising agents. Results Of the 12073 posts found on the seven accounts, 92.3% (11143) could be classified into six main themes: traditional culture, popular culture, social and business affairs, advertisement, public relations and tobacco culture. Posts under the theme of popular culture accounted for about half of total posts (49%), followed by ‘advertisement’ and ‘tobacco culture’ (both at 12%), ‘traditional culture’ and ‘public relations’ (both at 11%), and finally ‘social and business affairs’ (5%). 33% of posts included the words ‘cigarette’ or ‘smoking’ and 53% of posts included the tobacco brand name, indicating that tobacco companies carefully construct the topic and content of posts. Conclusions Weibo is an important new online marketing tool for the Chinese tobacco industry. Tobacco industry use of Weibo to promote brands and normalize smoking subverts China's ratification of the WHO FCTC. Policy to control tobacco promotion needs reforming to address this widespread circumvention of China's tobacco advertising ban. PMID:24914739

  20. Differentiation as symbiosis.

    PubMed

    Chigira, M; Watanabe, H

    1994-07-01

    Preservation of the identity of DNA is the ultimate goal of multicellular organisms. An abnormal DNA sequence in cells within an individual means its parasitic nature in cell society as shown in tumors. Somatic gene arrangement and gene mutation in development may be considered as de novo formation of parasites. It is likely that the developmental process with genetic alterations means symbiosis between altered cells and germ line cells preserving genetic information without alterations, when somatic alteration of DNA sequence is a major mechanism of differentiation. According to the selfish gene theory of Dawkins, germ line cells permit symbiosis when somatic cell society derives clear profit for the replication of original DNA copies. PMID:7968715

  1. Strategies for promoting renewables in a new electric industry

    SciTech Connect

    Driver, B.

    1996-12-31

    This paper describes strategies for promoting renewable resources in an era characterized by competitive pressures in the electric industry. It begins with a background section to describe the perspective from which I am writing and the nature of the pressures confronting renewables in 1996. Then, the paper turns to a discussion of the regulatory and other options to promote renewables in this environment. The major conclusion of the paper is that there is no {open_quotes}magic bullet{close_quotes} to guide the development of renewables through the developing competitive era within the electric industry. Indeed, it appears that the job can get done only through a combination of different measures at all levels of government. The author believes that among the most effective measures are likely to be: a national renewable resources generation standard; conditions attached to restructuring events; regional interstate compacts; regional risk-sharing consortia supported by federal and state tax and fiscal policy; and state {open_quotes}systems benefits charges;{close_quotes}

  2. Speciation by Symbiosis: the Microbiome and Behavior

    PubMed Central

    Shropshire, J. Dylan

    2016-01-01

    ABSTRACT Species are fundamental units of comparison in biology. The newly discovered importance and ubiquity of host-associated microorganisms are now stimulating work on the roles that microbes can play in animal speciation. We previously synthesized the literature and advanced concepts of speciation by symbiosis with notable attention to hybrid sterility and lethality. Here, we review recent studies and relevant data on microbes as players in host behavior and behavioral isolation, emphasizing the patterns seen in these analyses and highlighting areas worthy of additional exploration. We conclude that the role of microbial symbionts in behavior and speciation is gaining exciting traction and that the holobiont and hologenome concepts afford an evolving intellectual framework to promote research and intellectual exchange between disciplines such as behavior, microbiology, genetics, symbiosis, and speciation. Given the increasing centrality of microbiology in macroscopic life, microbial symbiosis is arguably the most neglected aspect of animal and plant speciation, and studying it should yield a better understanding of the origin of species. PMID:27034284

  3. 7 CFR 1260.169 - Promotion, research, consumer information and industry information.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... industry information. 1260.169 Section 1260.169 Agriculture Regulations of the Department of Agriculture... Operating Committee § 1260.169 Promotion, research, consumer information and industry information. The... approval any plans and projects for promotion, research, consumer information and industry...

  4. 7 CFR 1260.169 - Promotion, research, consumer information and industry information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... industry information. 1260.169 Section 1260.169 Agriculture Regulations of the Department of Agriculture... Operating Committee § 1260.169 Promotion, research, consumer information and industry information. The... approval any plans and projects for promotion, research, consumer information and industry...

  5. 7 CFR 1260.169 - Promotion, research, consumer information and industry information.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... industry information. 1260.169 Section 1260.169 Agriculture Regulations of the Department of Agriculture... Operating Committee § 1260.169 Promotion, research, consumer information and industry information. The... approval any plans and projects for promotion, research, consumer information and industry...

  6. 7 CFR 1260.169 - Promotion, research, consumer information and industry information.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... industry information. 1260.169 Section 1260.169 Agriculture Regulations of the Department of Agriculture... Operating Committee § 1260.169 Promotion, research, consumer information and industry information. The... approval any plans and projects for promotion, research, consumer information and industry...

  7. Expanding genomics of mycorrhizal symbiosis

    DOE PAGES

    Kuo, Alan; Kohler, Annegret; Martin, Francis M.; Grigoriev, Igor V.

    2014-11-04

    The mycorrhizal symbiosis between soil fungi and plant roots is a ubiquitous mutualism that plays key roles in plant nutrition, soil health, and carbon cycling. The symbiosis evolved repeatedly and independently as multiple morphotypes [e.g., arbuscular mycorrhizae (AM), ectomycorrhizal (ECM)] in multiple fungal clades (e.g., phyla Glomeromycota, Ascomycota, Basidiomycota). The accessibility and cultivability of many mycorrhizal partners make them ideal models for symbiosis studies. Alongside molecular, physiological, and ecological investigations, sequencing led to the first three mycorrhizal fungal genomes, representing two morphotypes and three phyla. The genome of the ECM basidiomycete Laccaria bicolor showed that the mycorrhizal lifestyle can evolvemore » through loss of plant cell wall-degrading enzymes (PCWDEs) and expansion of lineage-specific gene families such as short secreted protein (SSP) effectors. The genome of the ECM ascomycete Tuber melanosporum showed that the ECM type can evolve without expansion of families as in Laccaria, and thus a different set of symbiosis genes. The genome of the AM glomeromycete Rhizophagus irregularis showed that despite enormous phylogenetic distance and morphological difference from the other two fungi, symbiosis can involve similar solutions as symbiosis-induced SSPs and loss of PCWDEs. The three genomes provide a solid base for addressing fundamental questions about the nature and role of a vital mutualism.« less

  8. Expanding genomics of mycorrhizal symbiosis

    SciTech Connect

    Kuo, Alan; Kohler, Annegret; Martin, Francis M.; Grigoriev, Igor V.

    2014-11-04

    The mycorrhizal symbiosis between soil fungi and plant roots is a ubiquitous mutualism that plays key roles in plant nutrition, soil health, and carbon cycling. The symbiosis evolved repeatedly and independently as multiple morphotypes [e.g., arbuscular mycorrhizae (AM), ectomycorrhizal (ECM)] in multiple fungal clades (e.g., phyla Glomeromycota, Ascomycota, Basidiomycota). The accessibility and cultivability of many mycorrhizal partners make them ideal models for symbiosis studies. Alongside molecular, physiological, and ecological investigations, sequencing led to the first three mycorrhizal fungal genomes, representing two morphotypes and three phyla. The genome of the ECM basidiomycete Laccaria bicolor showed that the mycorrhizal lifestyle can evolve through loss of plant cell wall-degrading enzymes (PCWDEs) and expansion of lineage-specific gene families such as short secreted protein (SSP) effectors. The genome of the ECM ascomycete Tuber melanosporum showed that the ECM type can evolve without expansion of families as in Laccaria, and thus a different set of symbiosis genes. The genome of the AM glomeromycete Rhizophagus irregularis showed that despite enormous phylogenetic distance and morphological difference from the other two fungi, symbiosis can involve similar solutions as symbiosis-induced SSPs and loss of PCWDEs. The three genomes provide a solid base for addressing fundamental questions about the nature and role of a vital mutualism.

  9. Expanding genomics of mycorrhizal symbiosis

    PubMed Central

    Kuo, Alan; Kohler, Annegret; Martin, Francis M.; Grigoriev, Igor V.

    2014-01-01

    The mycorrhizal symbiosis between soil fungi and plant roots is a ubiquitous mutualism that plays key roles in plant nutrition, soil health, and carbon cycling. The symbiosis evolved repeatedly and independently as multiple morphotypes [e.g., arbuscular mycorrhizae (AM), ectomycorrhizal (ECM)] in multiple fungal clades (e.g., phyla Glomeromycota, Ascomycota, Basidiomycota). The accessibility and cultivability of many mycorrhizal partners make them ideal models for symbiosis studies. Alongside molecular, physiological, and ecological investigations, sequencing led to the first three mycorrhizal fungal genomes, representing two morphotypes and three phyla. The genome of the ECM basidiomycete Laccaria bicolor showed that the mycorrhizal lifestyle can evolve through loss of plant cell wall-degrading enzymes (PCWDEs) and expansion of lineage-specific gene families such as short secreted protein (SSP) effectors. The genome of the ECM ascomycete Tuber melanosporum showed that the ECM type can evolve without expansion of families as in Laccaria, and thus a different set of symbiosis genes. The genome of the AM glomeromycete Rhizophagus irregularis showed that despite enormous phylogenetic distance and morphological difference from the other two fungi, symbiosis can involve similar solutions as symbiosis-induced SSPs and loss of PCWDEs. The three genomes provide a solid base for addressing fundamental questions about the nature and role of a vital mutualism. PMID:25408690

  10. Symbiosis, Empathy, Suicidal Behavior, and the Family.

    ERIC Educational Resources Information Center

    Richman, Joseph

    1978-01-01

    This paper discusses the theoretical concept of symbiosis, as described by Mahler and her co-workers, and its clinical applications in suicidal situations. Also, the practical implications of the concept of symbiosis for assessment and treatment are discussed (Author)

  11. Mycorrhizal symbiosis in leeks increases plant growth under low phosphorus and affects the levels of specific flavonoid glycosides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction- Mycorrhizae symbiosis is a universal phenomenon in nature that promotes plant growth and food quality in most plants, especially, under phosphorus deficiency and water stress. Objective- The objective of this study was to assess the effects of mycorrhizal symbiosis on changes in the le...

  12. Industry Self-Regulation as a Means to Promote Nonproliferation

    SciTech Connect

    Hund, Gretchen; Elkhamri, Oksana O.

    2005-10-01

    Companies within numerous industries that have been “early adopters” of self-regulation concept, considering the environment and society alongside business issues, have realized several benefits and some competitive advantage while substantially improving their environmental performance. Given that proliferation prevention is also a public good, our premise is that the experience gained and lessons learned from the self-regulation initiative in other industries and more broadly in the arena of sustainable development provide a basis for examining the feasibility of developing self-regulation mechanisms applicable to industries involved with sensitive technologies (nuclear, radiological source, and other dual-use industries)

  13. 7 CFR 1220.230 - Promotion, research, consumer information, and industry information.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... industry information. 1220.230 Section 1220.230 Agriculture Regulations of the Department of Agriculture... Research Order Expenses and Assessments § 1220.230 Promotion, research, consumer information, and industry..., research, consumer information, and industry information activities with respect to soybean and...

  14. 7 CFR 1220.230 - Promotion, research, consumer information, and industry information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... industry information. 1220.230 Section 1220.230 Agriculture Regulations of the Department of Agriculture... Research Order Expenses and Assessments § 1220.230 Promotion, research, consumer information, and industry..., research, consumer information, and industry information activities with respect to soybean and...

  15. 7 CFR 1220.230 - Promotion, research, consumer information, and industry information.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... industry information. 1220.230 Section 1220.230 Agriculture Regulations of the Department of Agriculture... Research Order Expenses and Assessments § 1220.230 Promotion, research, consumer information, and industry..., research, consumer information, and industry information activities with respect to soybean and...

  16. 7 CFR 1220.230 - Promotion, research, consumer information, and industry information.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... industry information. 1220.230 Section 1220.230 Agriculture Regulations of the Department of Agriculture... Research Order Expenses and Assessments § 1220.230 Promotion, research, consumer information, and industry..., research, consumer information, and industry information activities with respect to soybean and...

  17. Symbiosis in Paramecium Bursaria.

    PubMed

    Karakashian, M W

    1975-01-01

    Paramecium bursaria normally appears green dut to several hundred symbiotic Chlorella which are dispersed throughout its cytoplasm. The symbionts are situated within individual vacuoles and these alga-vacuole complexes grow and divide at a rate compatible with that of the paramecium. The symbiotic units also persist through conjugation and the subsequent reorganization of the host. Studies of the benefit of the symbiosis to the ciliate hosts have shown that they are able to grow and survive better than aposymbiotic animals in environments deficient in bacteria. The symbionts are also able to extract nourishment from the host when it is well fed and they are deprived of light. The biochemical nature of these exchanges has not been determined. Potential symbionts usually enter the host in food vacuoles. If they are ingested in sufficient numbers, they are able to interfere with the normal course of host digestion, perhaps by preventing the release of digestive enzymes into the food vacuole. All natural symbionts of P. bursaria appear able to reinfect aposymbiotic cells. Some freeliving strains of Chlorella and related algae are also infective, but these associations are relatively unstable and provide little evident benefit to the host. Host susceptibility to infection by certain strains of free-living algae is invariably lost with time. This loss is specific and often rapid, but it does not occur simultaneously in subcultures derived from the original susceptible culture. The basis for these susceptibility changes is still unknown, but they may be related to long-lasting effect of the previous symbionts on the digestive efficiency of the paramecium host. PMID:785659

  18. Health Promotion and Industry: Where Interdisciplinary Research Meets Reality.

    ERIC Educational Resources Information Center

    Ricketts, Thomas C.; Kaluzny, Arnold D.

    1987-01-01

    Evaluation research in work-site health promotion offers an opportunity to test the effectiveness of work-site health promotion and disease prevention programs. Based on an evaluation of the research, an interdisciplinary approach to data collection and analysis is suggested, and policy implications are outlined. (TJH)

  19. Designing for multi-lifecycle to promote industrial ecology philosophy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper presents a design concept originally developed to suit the needs of the agro-industrial sector in the developing economies. It also highlights how this concept fits into other green design paradigms and to the goals of industrial ecology. The need to design for multi-lifecycles arose fro...

  20. The Microbiota, Chemical Symbiosis, and Human Disease

    PubMed Central

    Redinbo, Matthew R.

    2014-01-01

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

  1. 76 FR 53816 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order; Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... Agricultural Marketing Service 7 CFR Part 1217 RIN 0581-AD03 Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order; Correction AGENCY: Agricultural Marketing Service. ACTION..., 2011 (76 FR 46185), regarding softwood lumber. Corrections are made in the amendatory...

  2. 75 FR 61025 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-01

    ... September 18, 2008 (73 FR 49934; August 25, 2008), prescribed an importer declaration program and entry... Education and Industry Information Order; Referendum Procedures AGENCY: Agricultural Marketing Service, USDA... referendum to determine whether issuance of a proposed Softwood Lumber Research, Promotion,...

  3. A Role for Industry in Promoting Nuclear Security and Nonproliferation

    SciTech Connect

    Hund, Gretchen; Seward, Amy M.; Elkhamri, Oksana O.

    2009-11-01

    Industry has a unique opportunity and critical role to play in strengthening governmental efforts to prevent the spread of nuclear, radiological, and dual-use materials and technologies that could be used in a nuclear or radiological weapon. Governmental regulations and policies are in effect at both the national and international levels to inhibit access to such materials and technologies by illegitimate end-users. However, the discovery of an illegal nuclear network, spearheaded by Pakistani scientist A Q Khan, increased international concern about what more could be done to prevent proliferation. Industry is well-poised and has a strong incentive to take a more proactive role to complement existing governmental efforts. Companies can be a tremendous help in ensuring that illicit diversions do not occur by increasing their oversight over the supply chain.

  4. A health promotion program evaluation in a minority industry.

    PubMed

    Fowler, B A; Risner, P B

    1994-01-01

    Wellness or health promotion programs (HPP) in the worksite are beneficial to both employer and employee. Companies report reduced absenteeism and improved job performance and productivity (O'Donnell & Ainsworth, 1984; Glantz & Orr, 1986). These programs are vital for Black Americans who experience distressing disparity in the leading causes of mortality and morbidity when compared to White Americans. Black Americans also experience poorer health as a result of racism, prejudice, discrimination, economic issues, and social ills such as poverty and lack of access to health care. The major purpose of this study was to examine the effects of a nurse-delivered six-month pilot HPP on the health awareness and reported health behaviors of Black Americans in the workplace. Approximately 50 employees participated in the HPP. The overall health screening and evaluation survey results indicated that the HPP was effective in increasing health awareness and in changing health behaviors. Nurses can play an important leadership role in improving the health of Black Americans in the workplace.

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

    PubMed Central

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

    2014-01-01

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

  6. A novel reef coral symbiosis

    NASA Astrophysics Data System (ADS)

    Pantos, O.; Bythell, J. C.

    2010-09-01

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

  7. Is Industry-University Interaction Promoting Innovation in the Brazilian Pharmaceutical Industry?

    ERIC Educational Resources Information Center

    Paranhos, Julia; Hasenclever, Lia

    2011-01-01

    This paper analyses industry-university interaction and its characteristics in the Brazilian pharmaceutical system of innovation, taking account of the relevance of company strategies, the approach of the universities and the actions of government. By analysing primary and secondary data the authors show that, for as long as corporate investment…

  8. A secondary symbiosis in progress?

    PubMed

    Okamoto, Noriko; Inouye, Isao

    2005-10-14

    Algae have acquired plastids by developing an endosymbiotic relationship with either a cyanobacterium (primary endosymbiosis) or other eukaryotic algae (secondary endosymbiosis). We report a protist, which we tentatively refer to as Hatena, that hosts an endosymbiotic green algal partner but inherits it unevenly. The endosymbiosis causes drastic morphological changes to both the symbiont and the host cell architecture. This type of life cycle, in which endosymbiont integration has only partially converted the host from predator to autotroph, may represent an early stage of plastid acquisition through secondary symbiosis. PMID:16224014

  9. 76 FR 22751 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-22

    ... FR 61002) and a second rule pertained to proposed referendum procedures (75 FR 61025). Both rules... Register on October 1, 2010 (75 FR 61025). Copies of the rule were made available by USDA through the... Lumber Research, Promotion, Consumer Education and Industry Information Order; Referendum...

  10. An Industrial Promotion Survey: A Guide for Your Rural Community's Development. Extension Circular 134.

    ERIC Educational Resources Information Center

    Kuennen, Daniel S.

    Divided into 2 parts, this publication presents a brief review of facts concerning rural industrial expansion as relative to rural community development and describes the way in which a community should go about researching, compiling, and publishing an attractive promotion portfolio. To aid communities in the initial steps toward industrial…

  11. Perspectives on workplace health promotion among employees in low-wage industries

    PubMed Central

    Hammerback, Kristen; Hannon, Peggy A.; Harris, Jeffrey R.; Clegg-Thorp, Catherine; Kohn, Marlana; Parrish, Amanda

    2016-01-01

    Purpose Study goals were to (a) understand the attitudes of employees in low-wage industries toward workplace health promotion, including views on appropriateness of employer involvement in employee health, and level of interest in workplace health promotion overall and in specific programs; and (b) determine the potential for extending workplace health promotion to spouses and partners of these employees. Approach Forty-two 60-90-minute interviews Setting Interviews were conducted with couples (married or living together) in the Seattle/King County metropolitan area of Washington State. Participants Forty-two couples with one or more members working in one of five low-wage industries: accommodation/food services, education, health care/social assistance, manufacturing, and retail trade. Method Qualitative analysis of interview transcripts using grounded theory to identify themes. Results Employees consider workplace health promotion both appropriate and desirable, and believe it benefits employers through increased productivity and morale. Most have little personal experience with it and doubt their employers would prioritize employee health. Employees are most interested in efforts focused on nutrition and physical activity. Both employees and their partners support extending workplace health promotion to include partners. Conclusion Employees and their partners are interested in workplace health promotion if it addresses behaviors they care about. Concern over employer involvement in their personal health decisions is minimal; instead, employees view employer interest in their health as a sign that they are valued. PMID:25162321

  12. Differential spatio-temporal expression of carotenoid cleavage dioxygenases regulates apocarotenoid fluxes during AM symbiosis.

    PubMed

    López-Ráez, Juan A; Fernández, Iván; García, Juan M; Berrio, Estefanía; Bonfante, Paola; Walter, Michael H; Pozo, María J

    2015-01-01

    Apocarotenoids are a class of compounds that play important roles in nature. In recent years, a prominent role for these compounds in arbuscular mycorrhizal (AM) symbiosis has been shown. They are derived from carotenoids by the action of the carotenoid cleavage dioxygenase (CCD) enzyme family. In the present study, using tomato as a model, the spatio-temporal expression pattern of the CCD genes during AM symbiosis establishment and functioning was investigated. In addition, the levels of the apocarotenoids strigolactones (SLs), C13 α-ionol and C14 mycorradicin (C13/C14) derivatives were analyzed. The results suggest an increase in SLs promoted by the presence of the AM fungus at the early stages of the interaction, which correlated with an induction of the SL biosynthesis gene SlCCD7. At later stages, induction of SlCCD7 and SlCCD1 expression in arbusculated cells promoted the production of C13/C14 apocarotenoid derivatives. We show here that the biosynthesis of apocarotenoids during AM symbiosis is finely regulated throughout the entire process at the gene expression level, and that CCD7 constitutes a key player in this regulation. Once the symbiosis is established, apocarotenoid flux would be turned towards the production of C13/C14 derivatives, thus reducing SL biosynthesis and maintaining a functional symbiosis.

  13. Rhizobial symbiosis effect on the growth, metal uptake, and antioxidant responses of Medicago lupulina under copper stress.

    PubMed

    Kong, Zhaoyu; Mohamad, Osama Abdalla; Deng, Zhenshan; Liu, Xiaodong; Glick, Bernard R; Wei, Gehong

    2015-08-01

    The effects of rhizobial symbiosis on the growth, metal uptake, and antioxidant responses of Medicago lupulina in the presence of 200 mg kg(-1) Cu(2+) throughout different stages of symbiosis development were studied. The symbiosis with Sinorhizobium meliloti CCNWSX0020 induced an increase in plant growth and nitrogen content irrespective of the presence of Cu(2+). The total amount of Cu uptake of inoculated plants significantly increased by 34.0 and 120.4% in shoots and roots, respectively, compared with non-inoculated plants. However, although the rhizobial symbiosis promoted Cu accumulation both in shoots and roots, the increase in roots was much higher than in shoots, thus decreasing the translocation factor and helping Cu phytostabilization. The rate of lipid peroxidation was significantly decreased in both shoots and roots of inoculated vs. non-inoculated plants when measured either 8, 13, or 18 days post-inoculation. In comparison with non-inoculated plants, the activities of superoxide dismutase and ascorbate peroxidase of shoots of inoculated plants exposed to excess Cu were significantly elevated at different stages of symbiosis development; similar increases occurred in the activities of superoxide dismutase, catalase, and glutathione reductase of inoculated roots. The symbiosis with S. meliloti CCNWSX0020 also upregulated the corresponding genes involved in antioxidant responses in the plants treated with excess Cu. The results indicated that the rhizobial symbiosis with S. meliloti CCNWSX0020 not only enhanced plant growth and metal uptake but also improved the responses of plant antioxidant defense to excess Cu stress.

  14. Promoting physical activity and healthy eating: convergence in framing the role of industry.

    PubMed

    Dorfman, Lori; Yancey, Antronette K

    2009-10-01

    This commentary addresses a little explored aspect of prevention, namely, how public health practitioners conceptualize the roles of industries whose business interests may be at odds with physical activity and eating nutrient-rich foods. Taking their cues from successful campaigns in tobacco control, many public health advocates have framed obesity as a battle with the food industry. Such framing presents problems when it exacerbates existing tensions between practitioners in nutrition and physical activity, and alienates potential fitness industry partners. Creating healthy environments requires reframing expectations of all industries that influence physical activity and inactivity. A broader view of the influence of corporate practices on physical and social environments will help both physical activity and nutrition advocates identify what they can do together, and in partnership with the business sector, to create environments that promote activity and nutritious eating. PMID:19576928

  15. The Rhizobium-plant symbiosis.

    PubMed Central

    van Rhijn, P; Vanderleyden, J

    1995-01-01

    Rhizobium, Bradyrhizobium, and Azorhizobium species are able to elicit the formation of unique structures, called nodules, on the roots or stems of the leguminous host. In these nodules, the rhizobia convert atmospheric N2 into ammonia for the plant. To establish this symbiosis, signals are produced early in the interaction between plant and rhizobia and they elicit discrete responses by the two symbiotic partners. First, transcription of the bacterial nodulation (nod) genes is under control of the NodD regulatory protein, which is activated by specific plant signals, flavonoids, present in the root exudates. In return, the nod-encoded enzymes are involved in the synthesis and excretion of specific lipooligosaccharides, which are able to trigger on the host plant the organogenic program leading to the formation of nodules. An overview of the organization, regulation, and function of the nod genes and their participation in the determination of the host specificity is presented. PMID:7708010

  16. The role of tobacco advertising and promotion: themes employed in litigation by tobacco industry witnesses

    PubMed Central

    Goldberg, Marvin E; Davis, Ronald M; O'Keefe, Anne Marie

    2006-01-01

    Objectives To identify key themes related to tobacco advertising and promotion in testimony provided by tobacco industry‐affiliated witnesses in tobacco litigation, and to present countervailing evidence and arguments. Methods Themes in industry testimony were identified by review of transcripts of testimony in the Tobacco Deposition and Trial Testimony Archive (http://tobaccodocuments.org/datta) from a sample of defence witnesses, including three academic expert witnesses, six senior executives of tobacco companies, and one industry advertising consultant. Counterarguments to the themes embodied in defence testimony were based on information from peer‐reviewed literature, advertising trade publications, government reports, tobacco industry documents, and testimony provided by expert witnesses testifying for plaintiffs. Results Five major themes employed by defence witnesses were identified: (1) tobacco advertising has a relatively weak “share of voice” in the marketing environment and is a weak force in affecting smoking behaviour; (2) tobacco advertising and promotion do not create new smokers, expand markets, or increase total tobacco consumption; (3) the tobacco industry does not target, study, or track youth smoking; (4) tobacco advertising and promotion do not cause smoking initiation by youth; and (5) tobacco companies and the industry adhere closely to relevant laws, regulations, and industry voluntary codes. Substantial evidence exists in rebuttal to these arguments. Conclusions Tobacco industry‐affiliated witnesses have marshalled many arguments to deny the adverse effects of tobacco marketing activities and to portray tobacco companies as responsible corporate citizens. Effective rebuttals to these arguments exist, and plaintiffs' attorneys have, with varying degrees of success, presented them to judges and juries. PMID:17130625

  17. The Mutual Symbiosis between Inclusive Bi-Lingual Education and Multicultural Education

    ERIC Educational Resources Information Center

    Irby, Beverly J.; Tong, Fuhui; Lara-Alecio, Rafael

    2011-01-01

    In this article the authors postulate a mutual symbiosis between multicultural and inclusive bi-lingual education. Combining bi-lingual and multicultural education to create a symbiotic relationship can stimulate reform in schools and can promote inclusive educational systems, thereby keeping native languages and cultures alive for minority…

  18. Oral health promotion by the oral health products industry: unrecognised and unappreciated?

    PubMed

    Barnett, M L

    2008-03-01

    There is often ambivalence in the way dentists view the oral health care industry. On the one hand, there are the skeptics who view corporate activities as suspect, calling into question the validity of industry-sponsored research and considering all promotional activities as self-serving. On the other hand, there are those who will evaluate research, whether industry sponsored or not, on its merits and appreciate corporate philanthropy that aims to give something back to the profession, although at times the expectations of the amount of financial support available are markedly in excess of the actual amount based on dental product sales. (Yes--and don't let your young children see this!--the tooth fairy who goes around dispensing endless number of dollars or pounds or euros does not actually exist!) Recognizing that, of necessity, corporations exist to make a profit, I would submit that the relationship of responsible companies to the profession can often be looked at as a partnership in which both sides benefit. Ultimately, all have as a goal the improvement of the oral health of our patients (or consumers) which is facilitated by the availability of effective products. In addition to marketing products, the oral care industry plays a large, though oftentimes unnoticed, role in oral health promotion. For the most part, this involves targeted financial support or contributions of products that serve to enhance patients' understanding of oral diseases and the need for good oral care, and/or provide access to care for underserved groups. In the following sections, I will give some examples of industry-supported health promotion activities, most of which will be activities in the United States with which I am most familiar. These are examples only--the list is not intended to be exhaustive and a company's name will be included in only the few instances in which it is an integral part of the programme title. PMID:18435227

  19. Eco-Evo-Devo: developmental symbiosis and developmental plasticity as evolutionary agents.

    PubMed

    Gilbert, Scott F; Bosch, Thomas C G; Ledón-Rettig, Cristina

    2015-10-01

    The integration of research from developmental biology and ecology into evolutionary theory has given rise to a relatively new field, ecological evolutionary developmental biology (Eco-Evo-Devo). This field integrates and organizes concepts such as developmental symbiosis, developmental plasticity, genetic accommodation, extragenic inheritance and niche construction. This Review highlights the roles that developmental symbiosis and developmental plasticity have in evolution. Developmental symbiosis can generate particular organs, can produce selectable genetic variation for the entire animal, can provide mechanisms for reproductive isolation, and may have facilitated evolutionary transitions. Developmental plasticity is crucial for generating novel phenotypes, facilitating evolutionary transitions and altered ecosystem dynamics, and promoting adaptive variation through genetic accommodation and niche construction. In emphasizing such non-genomic mechanisms of selectable and heritable variation, Eco-Evo-Devo presents a new layer of evolutionary synthesis.

  20. Transnational tobacco industry promotion of the cigarette gifting custom in China

    PubMed Central

    Chu, Alexandria; Jiang, Nan; Glantz, Stanton A

    2011-01-01

    Objective To understand how British American Tobacco (BAT) and Philip Morris (PM) researched the role and popularity of cigarette gifting in forming relationships among Chinese customs and how they exploited the practice to promote their brands State Express 555 and Marlboro. Methods Searches and analysis of industry documents from the Legacy Tobacco Documents Library complemented by searches on LexisNexis Academic news, online search engines and information from the tobacco industry trade press. Results From 1980–1999, BAT and PM employed Chinese market research firms to gather consumer information about perceptions of foreign cigarettes and the companies discovered that cigarettes, especially prestigious ones, were gifted and smoked purposely for building relationships and social status in China. BAT and PM promoted their brands as gifts by enhancing cigarette cartons and promoting culturally themed packages, particularly during the gifting festivals of Chinese New Year and Mid-Autumn Festival to tie their brands in to festival values such as warmth, friendship and celebration. They used similar marketing in Chinese communities outside China. Conclusions BAT and PM tied their brands to Chinese cigarette gifting customs by appealing to social and cultural values of respect and personal honour. Decoupling cigarettes from their social significance in China and removing their appeal would probably reduce cigarette gifting and promote a decline in smoking. Tobacco control efforts in countermarketing, large graphic warnings and plain packaging to make cigarette packages less attractive as gifts could contribute to denormalising cigarette gifting. PMID:21282136

  1. Helping to promote healthy diets and lifestyles: the role of the food industry.

    PubMed

    Gassin, A L

    2001-12-01

    In order to be successful, public health nutrition strategies require the active collaboration of all stakeholders in the promotion of healthy diet and lifestyle patterns. The food industry plays an important role both in providing products that meet consumers' needs in terms of taste, convenience, quality, nutrition and value as well as in communicating to consumers about the importance of good nutrition, including the contribution of specific foods to a balanced diet. The food industry contributes to educational efforts regarding healthy diets and lifestyles both directly--through product labelling, advertising, educational materials, on-line communications and information provided by Consumer Services departments--and indirectly, through active involvement and participation in educational programmes pursued in collaboration with nutrition and health education authorities. Through ongoing dialogue with its consumers and research conducted on consumer knowledge and attitudes towards diet, the food industry can ensure that communications developed are motivating and relevant to consumers' lives. In this paper, the specific contribution of the food industry will be illustrated through the promotion of healthy eating habits among children, focusing in particular on the importance of the breakfast meal.

  2. How best to promote industrial pollution prevention through the effluent guidelines process. Recommendations of the industrial pollution prevention project (IP3) focus group

    SciTech Connect

    Not Available

    1994-05-01

    The Industrial Pollution Prevention Project (IP3) Focus Group was requested by EPA to provide specific recommendations on how best to promote industrial pollution prevention through the effluent guidelines process. In response to that request, the Group makes the following recommendations to EPA: To promote more industrial pollution prevention, the effluent guidelines process must (1) be more flexible, (2) address all media, and (3) impart a pollution prevention mindset to everyone throughout the effluent guidelines process. To accomplish this, EPA should adopt a specific new approach to the development and achievement of Best Available Technology (BAT) limits.

  3. Exploring How the Tobacco Industry Presents and Promotes Itself in Social Media

    PubMed Central

    Liang, Yunji; Zheng, Xiaolong; Zhou, Xingshe; Leischow, Scott James; Chung, Wingyan

    2015-01-01

    Background The commercial potential of social media is utilized by tobacco manufacturers and vendors for tobacco promotion online. However, the prevalence and promotional strategies of pro-tobacco content in social media are still not widely understood. Objective The goal of this study was to reveal what is presented by the tobacco industry, and how it promotes itself, on social media sites. Methods The top 70 popular cigarette brands are divided into two groups according to their retail prices: group H (brands with high retail prices) and group L (brands with low retail prices). Three comprehensive searches were conducted on Facebook, Wikipedia, and YouTube respectively using the top 70 popular cigarette brands as keywords. We identified tobacco-related content including history and culture, product features, health warnings, home page of cigarette brands, and Web-based tobacco shops. Furthermore, we examined the promotional strategies utilized in social media. Results According to the data collected from March 3, 2014 to March 10, 2014, 43 of the 70 representative cigarette brands had created 238 Facebook fan pages, 46 cigarette brands were identified in Wikipedia, and there were over 120,000 pro-tobacco videos on YouTube, associated with 61 cigarette brands. The main content presented on the three social media websites differs significantly. Wikipedia focuses on history and culture (67%, 32/48; P<.001). Facebook mainly covers history and culture (37%, 16/43; P<.001) and major products (35%, 15/43), while YouTube focuses on the features of major tobacco products (79%, 48/61; P=.04) and information about Web-based shops (49%, 30/61; P=.004). Concerning the content presented by groups H and L, there is no significant difference between the two groups. With regard to the promotional strategies used, sales promotions exist extensively in social media. Sales promotion is more prevalent on YouTube than on the other two sites (64%, 39/61 vs 35%, 15/43; P=.004

  4. [The attitude of physicians regarding the promotion strategies of the pharmaceutical industry].

    PubMed

    Castresana, Leonardo; Mejia, Raul; Aznar, Mireya

    2005-01-01

    Pharmaceutical companies invest large sums of money promoting their products. They use a multifaceted approach to drug promotion, incorporating techniques such as hospital and office detailing by pharmaceutical representatives. Although these practices are commonly used, little has been published about the attitude of physicians concerning their interaction with the pharmaceutical industry. We performed a cross sectional anonymous survey to identify the extent of and attitudes towards the relationship between the physicians and the pharmaceutical industry and its representatives with its impact on the knowledge, attitude and behavior of the physicians. Internists, cardiologists and dermatologists who work in ambulatory settings from private and public hospitals in Buenos Aires city participated in this study, 44% were female, 35% residents, 65% staff physicians, averaging 41 years of age. Of these, 86% receive medical samples frecuently, 39% desk gifts, 19% invitations to congresses and 12% free lunches. Half of the doctors believe that receiving benefits from the pharmaceutical industry has an influence on medical prescription, but only 27% accept this as influential in their own prescriptions. Residents consider, more frequently than others, that these activities affect their decisions, (42% vs. 18% p = 0.007, global 30%). Most of the participants consider appropriate receiving these benefits, although 35% think that they affect the final price of medications. In conclusion, there is a high level of interaction between the pharmaceutical industry and our medical population. Although the latter recognize the influence of these interactions on prescriptions and the elevation of the cost of the final product, they find it appropriate to receive benefits.

  5. Polyfire project- an example of an industrial research project promoting safe industrial production of fire-resistant nanocomposites

    NASA Astrophysics Data System (ADS)

    Vaquero, C.; López de Ipiña, J.; Galarza, N.; Hargreaves, B.; Weager, B.; Breen, C.

    2011-07-01

    New developments based on nanotechnology have to guarantee safe products and processes to be accepted by society. The Polyfire project will develop and scale-up techniques for processing halogen-free, fire-retardant nanocomposite materials and coatings based on unsaturated polyester resins and organoclays. The project includes a work package that will assess the Health and Environmental impacts derived from the manipulation of nanoparticles. This work package includes the following tasks: (1) Identification of Health and Environment Impacts derived from the processes, (2) Experimentation to study specific Nanoparticle Emissions, (3) Development of a Risk Management Methodology for the process, and (4) A Comparison of the Health and Environmental Impact of New and Existing Materials. To date, potential exposure scenarios to nanomaterials have been identified through the development of a Preliminary Hazard Analysis (PHA) of the new production processes. In the next step, these scenarios will be studied and simulated to evaluate potential emissions of nanomaterials. Polyfire is a collaborative European project, funded by the European Commission 7th Framework Programme (Grant Agreement No 229220). It features 11 partners from 5 countries (5 SMEs, 3 research institutes, 2 large companies, 1 association) and runs for three years (1st September 2009 - 31st August 2012). This project is an example of an industrial research development which aims to introduce to the market new products promoting the safe use of nanomaterials.

  6. Plant hormones as signals in arbuscular mycorrhizal symbiosis.

    PubMed

    Miransari, Mohammad; Abrishamchi, A; Khoshbakht, K; Niknam, V

    2014-06-01

    Arbuscular mycorrhizal (AM) fungi are non-specific symbionts developing mutual and beneficial symbiosis with most terrestrial plants. Because of the obligatory nature of the symbiosis, the presence of the host plant during the onset and proceeding of symbiosis is necessary. However, AM fungal spores are able to germinate in the absence of the host plant. The fungi detect the presence of the host plant through some signal communications. Among the signal molecules, which can affect mycorrhizal symbiosis are plant hormones, which may positively or adversely affect the symbiosis. In this review article, some of the most recent findings regarding the signaling effects of plant hormones, on mycorrhizal fungal symbiosis are reviewed. This may be useful for the production of plants, which are more responsive to mycorrhizal symbiosis under stress.

  7. Unethical and Deadly Symbiosis in Higher Education

    ERIC Educational Resources Information Center

    Crumbley, D. Larry; Flinn, Ronald; Reichelt, Kenneth J.

    2012-01-01

    As administrators are pressured to increase retention rates in accounting departments, and higher education in general, a deadly symbiosis is occurring. Most students and parents only wish for high grades, so year after year many educators engage in unethical grade inflation and course work deflation. Since administrators use the students to audit…

  8. Arbuscular mycorrhizal symbiosis induces strigolactone biosynthesis under drought and improves drought tolerance in lettuce and tomato.

    PubMed

    Ruiz-Lozano, Juan Manuel; Aroca, Ricardo; Zamarreño, Ángel María; Molina, Sonia; Andreo-Jiménez, Beatriz; Porcel, Rosa; García-Mina, José María; Ruyter-Spira, Carolien; López-Ráez, Juan Antonio

    2016-02-01

    Arbuscular mycorrhizal (AM) symbiosis alleviates drought stress in plants. However, the intimate mechanisms involved, as well as its effect on the production of signalling molecules associated with the host plant-AM fungus interaction remains largely unknown. In the present work, the effects of drought on lettuce and tomato plant performance and hormone levels were investigated in non-AM and AM plants. Three different water regimes were applied, and their effects were analysed over time. AM plants showed an improved growth rate and efficiency of photosystem II than non-AM plants under drought from very early stages of plant colonization. The levels of the phytohormone abscisic acid, as well as the expression of the corresponding marker genes, were influenced by drought stress in non-AM and AM plants. The levels of strigolactones and the expression of corresponding marker genes were affected by both AM symbiosis and drought. The results suggest that AM symbiosis alleviates drought stress by altering the hormonal profiles and affecting plant physiology in the host plant. In addition, a correlation between AM root colonization, strigolactone levels and drought severity is shown, suggesting that under these unfavourable conditions, plants might increase strigolactone production in order to promote symbiosis establishment to cope with the stress. PMID:26305264

  9. Arbuscular mycorrhizal symbiosis induces strigolactone biosynthesis under drought and improves drought tolerance in lettuce and tomato.

    PubMed

    Ruiz-Lozano, Juan Manuel; Aroca, Ricardo; Zamarreño, Ángel María; Molina, Sonia; Andreo-Jiménez, Beatriz; Porcel, Rosa; García-Mina, José María; Ruyter-Spira, Carolien; López-Ráez, Juan Antonio

    2016-02-01

    Arbuscular mycorrhizal (AM) symbiosis alleviates drought stress in plants. However, the intimate mechanisms involved, as well as its effect on the production of signalling molecules associated with the host plant-AM fungus interaction remains largely unknown. In the present work, the effects of drought on lettuce and tomato plant performance and hormone levels were investigated in non-AM and AM plants. Three different water regimes were applied, and their effects were analysed over time. AM plants showed an improved growth rate and efficiency of photosystem II than non-AM plants under drought from very early stages of plant colonization. The levels of the phytohormone abscisic acid, as well as the expression of the corresponding marker genes, were influenced by drought stress in non-AM and AM plants. The levels of strigolactones and the expression of corresponding marker genes were affected by both AM symbiosis and drought. The results suggest that AM symbiosis alleviates drought stress by altering the hormonal profiles and affecting plant physiology in the host plant. In addition, a correlation between AM root colonization, strigolactone levels and drought severity is shown, suggesting that under these unfavourable conditions, plants might increase strigolactone production in order to promote symbiosis establishment to cope with the stress.

  10. Practical Application of Methanol-Mediated Mutualistic Symbiosis between Methylobacterium Species and a Roof Greening Moss, Racomitrium japonicum

    PubMed Central

    Tani, Akio; Takai, Yuichiro; Suzukawa, Ikko; Akita, Motomu; Murase, Haruhiko; Kimbara, Kazuhide

    2012-01-01

    Bryophytes, or mosses, are considered the most maintenance-free materials for roof greening. Racomitrium species are most often used due to their high tolerance to desiccation. Because they grow slowly, a technology for forcing their growth is desired. We succeeded in the efficient production of R. japonicum in liquid culture. The structure of the microbial community is crucial to stabilize the culture. A culture-independent technique revealed that the cultures contain methylotrophic bacteria. Using yeast cells that fluoresce in the presence of methanol, methanol emission from the moss was confirmed, suggesting that it is an important carbon and energy source for the bacteria. We isolated Methylobacterium species from the liquid culture and studied their characteristics. The isolates were able to strongly promote the growth of some mosses including R. japonicum and seed plants, but the plant-microbe combination was important, since growth promotion was not uniform across species. One of the isolates, strain 22A, was cultivated with R. japonicum in liquid culture and in a field experiment, resulting in strong growth promotion. Mutualistic symbiosis can thus be utilized for industrial moss production. PMID:22479445

  11. Agro-food industry growth and obesity in China: what role for regulating food advertising and promotion and nutrition labelling?

    PubMed

    Hawkes, C

    2008-03-01

    Taking a food supply chain approach, this paper examines the regulation of food marketing and nutrition labelling as strategies to help combat obesity in China in an era of rapid agro-food industry growth. China is the largest food producer and consumer in the world. Since the early 1980s, the agro-food industry has undergone phenomenal expansion throughout the food supply chain, from agricultural production to trade, agro-food processing to food retailing, and from food service to advertising and promotion. This industry growth, alongside related socioeconomic changes and government policies, has encouraged a 'nutrition transition'. China's population, especially in urban areas, is now consuming significantly more energy from dietary fat, which is leading to higher rates of obesity. Regulation of food advertising and promotion and nutrition labelling has the potential to help prevent the further growth of obesity in China and encourage the agro-food industry to supplier healthier foods. Government legislation and guidance, as well as self-regulation and voluntary initiatives, are needed to reduce children's exposure to food advertising and promotion, and increase the effectiveness of nutrition labelling. Policies on food marketing and nutrition labelling should be adapted to the China context, and accompanied by further action throughout the food supply chain. Given China's unique characteristics and position in the world today, there is an opportunity for the government and the agro-food industry to lead the world by creating a balanced, health promoting model of complementary legislation and industry action. PMID:18307719

  12. Computer symbiosis: Emergence of symbiotic behavior through evolution

    SciTech Connect

    Ikegami, Takashi; Kaneko, Kunihiko

    1989-01-01

    Symbiosis is altruistic cooperation between distinct species. It is one of the most effective evolutionary processes, but its dynamics are not well understood as yet. A simple model of symbiosis is introduced, where we consider interactions between hosts and parasites and also mutations of hosts and parasites. It is found that a symbiotic state emerges for a suitable range of mutation rates. The symbiotic state is not static, but dynamically oscillates. Harmful parasites violating symbiosis appear periodically, but are rapidly extinguished by hosts and other parasites, and the symbiotic state is recovered. The emergence of ''Tit for Tat'' strategy to maintain symbiosis is discussed. 4 figs.

  13. Industry experience in promoting weekly iron-folic acid supplementation in the Philippines.

    PubMed

    Garcia, Josel; Datol-Barrett, Eva; Dizon, Maynilad

    2005-12-01

    After participating in a pilot project under a government-industry partnership to promote the adoption of weekly iron-folic acid supplementation among women of reproductive age in the Philippines in 1998, United Laboratories (UNILAB), the Philippines' largest private pharmaceutical company, decided in April 2002 to launch a weekly iron-folic acid supplement for pregnant and non-pregnant women under the brand name Femina. The business objective set for the Femina brand was to build the category of preventive iron-folic acid supplements in line with the Philippine Department of Health's advocacy on weekly supplementation as an alternate to daily dosing to reduce the prevalence of anemia in the country. The brand was supported with an integrated mix of traditional advertising media with complementary direct-to-consumer educational programs that aimed to create awareness of iron-deficiency anemia, its causes and effects, and the role of weekly intake of iron-folic acid in preventing the condition. Aggressive marketing support for 1 year was successful in creating awareness among the target women. Significant lessons derived from consumers identified opportunity areas that can be further addressed in developing advocacy programs on weekly iron supplementation implemented on a nationwide scale in the future.

  14. Developing environmental legislation to promote recycling of industrial by-products - an endless story?

    PubMed

    Sorvari, Jaana

    2008-01-01

    In Finland during the last few decades, mineral industrial residues (by-products) have been used in earthworks, but only to a limited extent relative to their total volume. The most important barrier to efficient recycling of by-products has been the need for a site-specific environmental permit, since the permit process tends to be time-consuming and laborious. In 2000 a working group was set up to prepare national legislation, i.e., a Government decree, in order to promote the use of by-products in earth construction. The aim was to exempt certain residues from the environmental permit obligation. At the first stage, the working group determined specific decision criteria for the selection of the by-products to be included. For the selected residues, the acceptable construction applications and material-specific environmental standards were defined. Various difficulties were encountered during the preparation of the decree. These were mainly caused by the lack of data and by some ongoing changes in environmental regulations. Furthermore, the draft decree received several critical and partly contradictory comments and proposals for amendments. This resulted in considerable delay in implementation.

  15. Industry experience in promoting weekly iron-folic acid supplementation in the Philippines.

    PubMed

    Garcia, Josel; Datol-Barrett, Eva; Dizon, Maynilad

    2005-12-01

    After participating in a pilot project under a government-industry partnership to promote the adoption of weekly iron-folic acid supplementation among women of reproductive age in the Philippines in 1998, United Laboratories (UNILAB), the Philippines' largest private pharmaceutical company, decided in April 2002 to launch a weekly iron-folic acid supplement for pregnant and non-pregnant women under the brand name Femina. The business objective set for the Femina brand was to build the category of preventive iron-folic acid supplements in line with the Philippine Department of Health's advocacy on weekly supplementation as an alternate to daily dosing to reduce the prevalence of anemia in the country. The brand was supported with an integrated mix of traditional advertising media with complementary direct-to-consumer educational programs that aimed to create awareness of iron-deficiency anemia, its causes and effects, and the role of weekly intake of iron-folic acid in preventing the condition. Aggressive marketing support for 1 year was successful in creating awareness among the target women. Significant lessons derived from consumers identified opportunity areas that can be further addressed in developing advocacy programs on weekly iron supplementation implemented on a nationwide scale in the future. PMID:16466091

  16. Arbuscular mycorrhizal fungi in terms of symbiosis-parasitism continuum.

    PubMed

    Schmidt, B; Gaşpar, S; Camen, D; Ciobanu, I; Sumălan, R

    2011-01-01

    Arbuscular mycorrhizal fungi are forming the most wide-spread mycorrhizal relationships on Earth. Mycorrhiza contributes to phosphorous acquisition, water absorption and resistance to diseases. The fungus promotes the absorption of nutrients and water from soil, meanwhile the host plant offers photosynthetic assimilates in exchange, like carbohydrates, as energy source. The plant benefits from the contribution of symbiotic partner only when nutrients are in low concentrations in soil and the root system would not be able to absorb sufficiently the minerals. When the help of mycorrhizal fungi is not necessarily needed, the host plant is making an economy of energy, suppressing the development of fungi in the internal radicular space. In this moment, the nature of relationship turns from symbiotic to parasitic, triggering a series of defensive reactions from the plant. Also, there were several cases reported when the presence of arbuscular mycorrhizal fungi negatively influenced the host plant. For example, in adverse environmental conditions, like very high temperatures, instead of determining a higher plant biomass and flowering, the mycorrhiza reduces the growth of the host plant. We conducted a pot experiment with hydroponic culture to examine the effect of arbuscular mycorrhiza on development of French marigold as a host plant. As experimental variants, the phosphorous content in nutrient medium and temperature varied. Plants were artificially infected with arbuscular mycorrhizal fungi using a commercial inoculum containing three fungal species, as following: Glomus intraradices, Glomus etunicatum and Glomus claroideum. Colonization intensity and arbuscular richness were checked using root staining with aniline blue and estimation with the Trouvelot method. To observe the differences between plants from the experimental variants, we examined the number of side shoots, flower buds and fully developed flowers, fresh biomass and total leaf area. Results show that

  17. Femtosecond laser-fabricated biochip for studying symbiosis between Phormidium and seedling root

    NASA Astrophysics Data System (ADS)

    Ishikawa, Nobuaki; Hanada, Yasutaka; Ishikawa, Ikuko; Sugioka, Koji; Midorikawa, Katsumi

    2015-06-01

    We present the fabrication of a waveguide-like structure in a polydimethylsiloxane (PDMS) polymer substrate using a femtosecond laser to study the mechanism of symbiosis between filamentous cyanobacteria, Phormidium, and a seedling root. While symbiosis occurring underground promotes the growth of vegetable seedlings, the details of the mechanism remain unclear. Understanding the mechanisms of Phormidium gliding to the seedling root will facilitate improving the mat formation of Phormidium, which will lead to increased vegetable production. We assumed a symbiosis mechanism in which sunlight propagates through the seedling root and is scattered underground to guide the Phormidium gliding. Once attached to the root, Phormidium uses the scattered light for photosynthesis. Photosynthetic products, in turn, promote an increase in Phormidium mat formation and vegetable growth. To verify this assumption, the optical characteristics of the seedling root were investigated. A waveguide-like structure with the same optical characteristics of the root was subsequently fabricated by femtosecond laser in PDMS polymer to assess the light illumination effect on Phormidium behavior.

  18. The Symbiodinium kawagutii genome illuminates dinoflagellate gene expression and coral symbiosis.

    PubMed

    Lin, Senjie; Cheng, Shifeng; Song, Bo; Zhong, Xiao; Lin, Xin; Li, Wujiao; Li, Ling; Zhang, Yaqun; Zhang, Huan; Ji, Zhiliang; Cai, Meichun; Zhuang, Yunyun; Shi, Xinguo; Lin, Lingxiao; Wang, Lu; Wang, Zhaobao; Liu, Xin; Yu, Sheng; Zeng, Peng; Hao, Han; Zou, Quan; Chen, Chengxuan; Li, Yanjun; Wang, Ying; Xu, Chunyan; Meng, Shanshan; Xu, Xun; Wang, Jun; Yang, Huanming; Campbell, David A; Sturm, Nancy R; Dagenais-Bellefeuille, Steve; Morse, David

    2015-11-01

    Dinoflagellates are important components of marine ecosystems and essential coral symbionts, yet little is known about their genomes. We report here on the analysis of a high-quality assembly from the 1180-megabase genome of Symbiodinium kawagutii. We annotated protein-coding genes and identified Symbiodinium-specific gene families. No whole-genome duplication was observed, but instead we found active (retro)transposition and gene family expansion, especially in processes important for successful symbiosis with corals. We also documented genes potentially governing sexual reproduction and cyst formation, novel promoter elements, and a microRNA system potentially regulating gene expression in both symbiont and coral. We found biochemical complementarity between genomes of S. kawagutii and the anthozoan Acropora, indicative of host-symbiont coevolution, providing a resource for studying the molecular basis and evolution of coral symbiosis. PMID:26542574

  19. The Symbiodinium kawagutii genome illuminates dinoflagellate gene expression and coral symbiosis.

    PubMed

    Lin, Senjie; Cheng, Shifeng; Song, Bo; Zhong, Xiao; Lin, Xin; Li, Wujiao; Li, Ling; Zhang, Yaqun; Zhang, Huan; Ji, Zhiliang; Cai, Meichun; Zhuang, Yunyun; Shi, Xinguo; Lin, Lingxiao; Wang, Lu; Wang, Zhaobao; Liu, Xin; Yu, Sheng; Zeng, Peng; Hao, Han; Zou, Quan; Chen, Chengxuan; Li, Yanjun; Wang, Ying; Xu, Chunyan; Meng, Shanshan; Xu, Xun; Wang, Jun; Yang, Huanming; Campbell, David A; Sturm, Nancy R; Dagenais-Bellefeuille, Steve; Morse, David

    2015-11-01

    Dinoflagellates are important components of marine ecosystems and essential coral symbionts, yet little is known about their genomes. We report here on the analysis of a high-quality assembly from the 1180-megabase genome of Symbiodinium kawagutii. We annotated protein-coding genes and identified Symbiodinium-specific gene families. No whole-genome duplication was observed, but instead we found active (retro)transposition and gene family expansion, especially in processes important for successful symbiosis with corals. We also documented genes potentially governing sexual reproduction and cyst formation, novel promoter elements, and a microRNA system potentially regulating gene expression in both symbiont and coral. We found biochemical complementarity between genomes of S. kawagutii and the anthozoan Acropora, indicative of host-symbiont coevolution, providing a resource for studying the molecular basis and evolution of coral symbiosis.

  20. Not Waiting for Godot: The Evolution of Health Promotion at PPG Industries.

    PubMed

    Colombi, Alberto M; Pringle, Janice L; Welsh, George T

    2008-04-01

    PPG Industries is a manufacturer of coatings, chemicals, optical products, specialty materials, glass, and fiberglass. The company's approach to healthcare combines perhaps 2 disparate concepts. The first is that employee health and behavior change relies to a large degree on employee awareness and ownership of their own health and second that "what gets measured gets done." It is widely acknowledged that one of the best tools for employee awareness is the health risk appraisal tool. Additional components of employee awareness include knowing key individual health metrics and effectively engaging with healthcare providers. As a leading global manufacturer, PPG well understands the critical importance of cost accounting and financial metrics to drive business decisions. PPG's perhaps unique approach comes from the strong marriage of individual health/wellness promotion and frequent, timely, and informative financial metrics on health and the cost of care. Combining capacity building through the mobilization of volunteer wellness teams with expert interventions and financial discipline is a feature of the experience here described. This approach has resulted in both management and employee engagement in the issue and has allowed PPG to bend the curve of ever-increasing healthcare costs and achieve cost increases per employee at one half the reported national average for companies of comparable size. Because this journal is dedicated to health and drug benefits, we gathered an appropriately representative team composed of a physician, an epidemiologist who resides in a pharmacy school, and a benefits manager. The team evolved from a common vision to identify ways of improving employee health and well-being. The team presented both as keynote speakers and as contributors to a breakout session at the National Symposium on Work-Life organized in 2007 by the National Institute for Occupational Safety and Health, a federal agency of the Centers for Disease Control and

  1. Modeling symbiosis by interactions through species carrying capacities

    NASA Astrophysics Data System (ADS)

    Yukalov, V. I.; Yukalova, E. P.; Sornette, D.

    2012-08-01

    We introduce a mathematical model of symbiosis between different species by taking into account the influence of each species on the carrying capacities of the others. The modeled entities can pertain to biological and ecological societies or to social, economic and financial societies. Our model includes three basic types: symbiosis with direct mutual interactions, symbiosis with asymmetric interactions, and symbiosis without direct interactions. In all cases, we provide a complete classification of all admissible dynamical regimes. The proposed model of symbiosis turned out to be very rich, as it exhibits four qualitatively different regimes: convergence to stationary states, unbounded exponential growth, finite-time singularity, and finite-time death or extinction of species.

  2. Reciprocal genomic evolution in the ant–fungus agricultural symbiosis

    PubMed Central

    Nygaard, Sanne; Hu, Haofu; Li, Cai; Schiøtt, Morten; Chen, Zhensheng; Yang, Zhikai; Xie, Qiaolin; Ma, Chunyu; Deng, Yuan; Dikow, Rebecca B.; Rabeling, Christian; Nash, David R.; Wcislo, William T.; Brady, Seán G.; Schultz, Ted R.; Zhang, Guojie; Boomsma, Jacobus J.

    2016-01-01

    The attine ant–fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal cultivars. We show that ant subsistence farming probably originated in the early Tertiary (55–60 MYA), followed by further transitions to the farming of fully domesticated cultivars and leaf-cutting, both arising earlier than previously estimated. Evolutionary modifications in the ants include unprecedented rates of genome-wide structural rearrangement, early loss of arginine biosynthesis and positive selection on chitinase pathways. Modifications of fungal cultivars include loss of a key ligninase domain, changes in chitin synthesis and a reduction in carbohydrate-degrading enzymes as the ants gradually transitioned to functional herbivory. In contrast to human farming, increasing dependence on a single cultivar lineage appears to have been essential to the origin of industrial-scale ant agriculture. PMID:27436133

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

    PubMed

    Nygaard, Sanne; Hu, Haofu; Li, Cai; Schiøtt, Morten; Chen, Zhensheng; Yang, Zhikai; Xie, Qiaolin; Ma, Chunyu; Deng, Yuan; Dikow, Rebecca B; Rabeling, Christian; Nash, David R; Wcislo, William T; Brady, Seán G; Schultz, Ted R; Zhang, Guojie; Boomsma, Jacobus J

    2016-01-01

    The attine ant-fungus agricultural symbiosis evolved over tens of millions of years, producing complex societies with industrial-scale farming analogous to that of humans. Here we document reciprocal shifts in the genomes and transcriptomes of seven fungus-farming ant species and their fungal cultivars. We show that ant subsistence farming probably originated in the early Tertiary (55-60 MYA), followed by further transitions to the farming of fully domesticated cultivars and leaf-cutting, both arising earlier than previously estimated. Evolutionary modifications in the ants include unprecedented rates of genome-wide structural rearrangement, early loss of arginine biosynthesis and positive selection on chitinase pathways. Modifications of fungal cultivars include loss of a key ligninase domain, changes in chitin synthesis and a reduction in carbohydrate-degrading enzymes as the ants gradually transitioned to functional herbivory. In contrast to human farming, increasing dependence on a single cultivar lineage appears to have been essential to the origin of industrial-scale ant agriculture. PMID:27436133

  4. Symbiosis catalyses niche expansion and diversification

    PubMed Central

    Joy, Jeffrey B.

    2013-01-01

    Interactions between species are important catalysts of the evolutionary processes that generate the remarkable diversity of life. Symbioses, conspicuous and inherently interesting forms of species interaction, are pervasive throughout the tree of life. However, nearly all studies of the impact of species interactions on diversification have concentrated on competition and predation leaving unclear the importance of symbiotic interaction. Here, I show that, as predicted by evolutionary theories of symbiosis and diversification, multiple origins of a key innovation, symbiosis between gall-inducing insects and fungi, catalysed both expansion in resource use (niche expansion) and diversification. Symbiotic lineages have undergone a more than sevenfold expansion in the range of host-plant taxa they use relative to lineages without such fungal symbionts, as defined by the genetic distance between host plants. Furthermore, symbiotic gall-inducing insects are more than 17 times as diverse as their non-symbiotic relatives. These results demonstrate that the evolution of symbiotic interaction leads to niche expansion, which in turn catalyses diversification. PMID:23390106

  5. Osmoregulation in anthozoan-dinoflagellate symbiosis.

    PubMed

    Mayfield, Anderson B; Gates, Ruth D

    2007-05-01

    Endosymbiosis creates a unique osmotic circumstance. Hosts are not only responsible for balancing their internal osmolarity with respect to the external environment, but they must also maintain a compatible osmotic environment for their endosymbionts, which may themselves contribute to the net osmolarity of the host cell through molecular fluxes and/or exchange. Cnidarian hosts that harbor intracellular dinoflagellates (zooxanthellae) are excellent examples of such a symbiosis. These associations are characterized by the exchange of osmotically active compounds, but they are temporally stable under normal environmental conditions indicating that these osmotically driven exchanges are effectively and rapidly regulated. Although we have some knowledge about how asymbiotic anthozoans and algae osmoregulate, our understanding of the physiological mechanisms involved in regulating an intact anthozoan-dinoflagellate symbiosis is poor. Large-scale expulsion of endosymbiotic zooxanthellae, or bleaching, is currently considered to be one of the greatest threats to coral reefs worldwide. To date, there has been little consideration of the osmotic scenarios that occur when these symbioses are exposed to the conditions that normally elicit bleaching, such as increased seawater temperatures and UV radiation. Here we review what is known about osmoregulation and osmotic stress in anthozoans and dinoflagellates and discuss the osmotic implications of exposure to environmental stress in these globally distributed and ecologically important symbioses.

  6. Auxin influences strigolactones in pea mycorrhizal symbiosis.

    PubMed

    Foo, E

    2013-03-15

    Hormone interactions are essential for the control of many developmental processes, including intracellular symbioses. The interaction between auxin and the new plant hormone strigolactone in the regulation of arbuscular mycorrhizal symbiosis was examined in one of the few auxin deficient mutants available in a mycorrhizal species, the auxin-deficient bsh mutant of pea (Pisum sativum). Mycorrhizal colonisation with the fungus Glomus intraradices was significantly reduced in the low auxin bsh mutant. The bsh mutant also exhibited a reduction in strigolactone exudation and the expression of a key strigolactone biosynthesis gene (PsCCD8). Strigolactone exudation was also reduced in wild type plants when the auxin content was reduced by stem girdling. Low strigolactone levels appear to be at least partially responsible for the reduced colonisation of the bsh mutant, as application of the synthetic strigolactone GR24 could partially rescue the mycorrhizal phenotype of bsh mutants. Data presented here indicates root auxin content was correlated with strigolactone exudation in both mutant and wild type plants. Mutant studies suggest that auxin may regulate early events in the formation of arbuscular mycorrhizal symbiosis by controlling strigolactone levels, both in the rhizosphere and possibly during early root colonisation. PMID:23219475

  7. Forests trapped in nitrogen limitation--an ecological market perspective on ectomycorrhizal symbiosis.

    PubMed

    Franklin, Oskar; Näsholm, Torgny; Högberg, Peter; Högberg, Mona N

    2014-07-01

    Ectomycorrhizal symbiosis is omnipresent in boreal forests, where it is assumed to benefit plant growth. However, experiments show inconsistent benefits for plants and volatility of individual partnerships, which calls for a re-evaluation of the presumed role of this symbiosis. We reconcile these inconsistencies by developing a model that demonstrates how mycorrhizal networking and market mechanisms shape the strategies of individual plants and fungi to promote symbiotic stability at the ecosystem level. The model predicts that plants switch abruptly from a mixed strategy with both mycorrhizal and nonmycorrhizal roots to a purely mycorrhizal strategy as soil nitrogen availability declines, in agreement with the frequency distribution of ectomycorrhizal colonization intensity across a wide-ranging data set. In line with observations in field-scale isotope labeling experiments, the model explains why ectomycorrhizal symbiosis does not alleviate plant nitrogen limitation. Instead, market mechanisms may generate self-stabilization of the mycorrhizal strategy via nitrogen depletion feedback, even if plant growth is ultimately reduced. We suggest that this feedback mechanism maintains the strong nitrogen limitation ubiquitous in boreal forests. The mechanism may also have the capacity to eliminate or even reverse the expected positive effect of rising CO2 on tree growth in strongly nitrogen-limited boreal forests.

  8. Forests trapped in nitrogen limitation--an ecological market perspective on ectomycorrhizal symbiosis.

    PubMed

    Franklin, Oskar; Näsholm, Torgny; Högberg, Peter; Högberg, Mona N

    2014-07-01

    Ectomycorrhizal symbiosis is omnipresent in boreal forests, where it is assumed to benefit plant growth. However, experiments show inconsistent benefits for plants and volatility of individual partnerships, which calls for a re-evaluation of the presumed role of this symbiosis. We reconcile these inconsistencies by developing a model that demonstrates how mycorrhizal networking and market mechanisms shape the strategies of individual plants and fungi to promote symbiotic stability at the ecosystem level. The model predicts that plants switch abruptly from a mixed strategy with both mycorrhizal and nonmycorrhizal roots to a purely mycorrhizal strategy as soil nitrogen availability declines, in agreement with the frequency distribution of ectomycorrhizal colonization intensity across a wide-ranging data set. In line with observations in field-scale isotope labeling experiments, the model explains why ectomycorrhizal symbiosis does not alleviate plant nitrogen limitation. Instead, market mechanisms may generate self-stabilization of the mycorrhizal strategy via nitrogen depletion feedback, even if plant growth is ultimately reduced. We suggest that this feedback mechanism maintains the strong nitrogen limitation ubiquitous in boreal forests. The mechanism may also have the capacity to eliminate or even reverse the expected positive effect of rising CO2 on tree growth in strongly nitrogen-limited boreal forests. PMID:24824576

  9. Structural relations of late night snacking choice attributes and health promotion behaviors according to dietary style of industrial workers

    PubMed Central

    Park, Young Il

    2014-01-01

    BACKGROUND/OBJECTIVES This research was conducted to develop a construct model regarding the dietary style, late night snacking choice attributes and health promotion behaviors of industrial workers. SUBJECTS/METHODS The surveys were collected during the period between January and February 2013. A statistical analysis of 888 industrial workers was conducted using SPSS 12.0 for Windows and SEM (Structural Equation Model) using AMOS (Analysis of Moment Structure) 5.0 statistics package. RESULTS The results of the correlations between all variables showed significant positive correlations (P < 0.05). Results of factors analysis on dietary styles were categorized into five factors and health promotion behaviors were categorized into four. The reliability of these findings was supported by a Cronbach's alpha coefficient of 0.6 and higher for all other factors. After obtaining the factors from processing an exploratory factor analysis and the end results supported the validity. In an attempt to study the late night snacking choice attributes in accordance to dietary styles and the health promotion behaviors of industrial workers, a structural equation model was constructed and analyzed. CONCLUSIONS All tests proved the model satisfied the recommended levels of the goodness on fit index, and thus, the overall research model was proved to be appropriate. PMID:25110564

  10. Arbuscular mycorrhizal symbiosis influences strigolactone production under salinity and alleviates salt stress in lettuce plants.

    PubMed

    Aroca, Ricardo; Ruiz-Lozano, Juan Manuel; Zamarreño, Angel María; Paz, José Antonio; García-Mina, José María; Pozo, María José; López-Ráez, Juan Antonio

    2013-01-01

    Arbuscular mycorrhizal (AM) symbiosis can alleviate salt stress in plants. However the intimate mechanisms involved, as well as the effect of salinity on the production of signalling molecules associated to the host plant-AM fungus interaction remains largely unknown. In the present work, we have investigated the effects of salinity on lettuce plant performance and production of strigolactones, and assessed its influence on mycorrhizal root colonization. Three different salt concentrations were applied to mycorrhizal and non-mycorrhizal plants, and their effects, over time, analyzed. Plant biomass, stomatal conductance, efficiency of photosystem II, as well as ABA content and strigolactone production were assessed. The expression of ABA biosynthesis genes was also analyzed. AM plants showed improved growth rates and a better performance of physiological parameters such as stomatal conductance and efficiency of photosystem II than non-mycorrhizal plants under salt stress since very early stages - 3 weeks - of plant colonization. Moreover, ABA levels were lower in those plants, suggesting that they were less stressed than non-colonized plants. On the other hand, we show that both AM symbiosis and salinity influence strigolactone production, although in a different way in AM and non-AM plants. The results suggest that AM symbiosis alleviates salt stress by altering the hormonal profiles and affecting plant physiology in the host plant. Moreover, a correlation between strigolactone production, ABA content, AM root colonization and salinity level is shown. We propose here that under these unfavourable conditions, plants increase strigolactone production in order to promote symbiosis establishment to cope with salt stress.

  11. 78 FR 58956 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order; Changes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-25

    ...; ] DEPARTMENT OF AGRICULTURE Agricultural Marketing Service 7 CFR Part 1217 Softwood Lumber Research, Promotion... Order with oversight by the U.S. Department of Agriculture (USDA). Under the Order, assessments are... Internet at: http://www.regulations.gov or to the Promotion and Economics Division, Fruit and...

  12. Promoting creativity in the electric utility industry under a regulated and/or de-regulated environment

    SciTech Connect

    Riley, H.W. Jr.

    1996-12-31

    Over the years, utilities have been going through cost cutting measures and efficiency improvements in an effort to be more competitive or stay competitive within their market territory. The next logical step for a utility to take is to promote Creativity. With a creative environment in place, utilities can keep pace with the changes in the industry and maintain or attain their competitive advantage. The goal of the creative electric utility work-force is to keep up with changes in the industry and become more competitive as the market becomes more competitive. Utilities can change the way they do business by utilizing an effectively trained and skilled work-force on the subject of creative thinking. Creativity within a work-force depends on the employees desire to understand difficult aspects of his or her life. This paper will provide the foundation for linking Creativity and the electric utility industry.

  13. The case for responsibility of the IT industry to promote equality for women in computing.

    PubMed

    Turner, E

    2001-04-01

    This paper investigates the relationship between the role that information technology (IT) has played in the development of women's employment, the possibility of women having a significant influence on the technology's development, and the way that the IT industry perceives women as computer scientists, users and consumers. The industry's perception of women and men is investigated through the portrayal of them in computing advertisements. While women are increasingly updating their technological skills and know-how, and through this process are entering some positions in the workplace traditionally occupied by men, these achievements are not mirrored in their social and occupational status. The computer industry and higher education have worryingly low numbers of women, while the possibility of women influencing the development of computer technology is just emerging in feminist research. This paper argues that, though the IT industry, through their self-regulatory codes, subscribes to equal treatment of sexes, races and persons with disabilities, the industry nevertheless paints a stereotyped picture of inequality when portraying men and women in computer advertisements. As long as such a perception of women prevails within the industry, it will stand as a barrier to women having equal access to computer technology. If advertisements influence the way society perceives major social constructs and issues, then the computing industry has a social responsibility to portray men and women in an equal and non-stereotypical fashion. PMID:11349365

  14. Symbiosis and the origin of eukaryotic motility

    NASA Technical Reports Server (NTRS)

    Margulis, L.; Hinkle, G.

    1991-01-01

    Ongoing work to test the hypothesis of the origin of eukaryotic cell organelles by microbial symbioses is discussed. Because of the widespread acceptance of the serial endosymbiotic theory (SET) of the origin of plastids and mitochondria, the idea of the symbiotic origin of the centrioles and axonemes for spirochete bacteria motility symbiosis was tested. Intracellular microtubular systems are purported to derive from symbiotic associations between ancestral eukaryotic cells and motile bacteria. Four lines of approach to this problem are being pursued: (1) cloning the gene of a tubulin-like protein discovered in Spirocheata bajacaliforniesis; (2) seeking axoneme proteins in spirochets by antibody cross-reaction; (3) attempting to cultivate larger, free-living spirochetes; and (4) studying in detail spirochetes (e.g., Cristispira) symbiotic with marine animals. Other aspects of the investigation are presented.

  15. Brassinosteroids Regulate Root Growth, Development, and Symbiosis.

    PubMed

    Wei, Zhuoyun; Li, Jia

    2016-01-01

    Brassinosteroids (BRs) are natural plant hormones critical for growth and development. BR deficient or signaling mutants show significantly shortened root phenotypes. However, for a long time, it was thought that these phenotypes were solely caused by reduced cell elongation in the mutant roots. Functions of BRs in regulating root development have been largely neglected. Nonetheless, recent detailed analyses, revealed that BRs are not only involved in root cell elongation but are also involved in many aspects of root development, such as maintenance of meristem size, root hair formation, lateral root initiation, gravitropic response, mycorrhiza formation, and nodulation in legume species. In this review, current findings on the functions of BRs in mediating root growth, development, and symbiosis are discussed.

  16. Expanding the Pool of Federal Policy Options to Promote Industrial Energy Efficiency

    SciTech Connect

    Brown, Dr. Marilyn Ann; Cox, Matthew; Jackson, Roderick K; Lapsa, Melissa Voss

    2011-01-01

    Improving the energy efficiency of industry is essential for maintaining the viability of domestic manufacturing, especially in a world economy where production is shifting to low-cost, less regulated developing countries. Numerous studies have shown the potential for significant cost-effective energy-savings in U.S. industries, but the realization of this potential is hindered by regulatory, information, workforce, and financial obstacles. This report evaluates seven federal policy options aimed at improving the energy efficiency of industry, grounded in an understanding of industrial decision-making and the barriers to efficiency improvements. Detailed analysis employs the Georgia Institute of Technology's version of the National Energy Modeling System and spreadsheet calculations, generating a series of benefit/cost metrics spanning private and public costs and energy bill savings, as well as air pollution benefits and the social cost of carbon. Two of the policies would address regulatory hurdles (Output-Based Emissions Standards and a federal Energy Portfolio Standard with Combined Heat and Power); three would help to fill information gaps and workforce training needs (the Superior Energy Performance program, Implementation Support Services, and a Small Firm Energy Management program); and two would tackle financial barriers (Tax Lien Financing and Energy-Efficient Industrial Motor Rebates). The social benefit-cost ratios of these policies appear to be highly favorable based on a range of plausible assumptions. Each of the seven policy options has an appropriate federal role, broad applicability across industries, utilizes readily available technologies, and all are administratively feasible.

  17. Promoter Screening from Bacillus subtilis in Various Conditions Hunting for Synthetic Biology and Industrial Applications.

    PubMed

    Song, Yafeng; Nikoloff, Jonas M; Fu, Gang; Chen, Jingqi; Li, Qinggang; Xie, Nengzhong; Zheng, Ping; Sun, Jibin; Zhang, Dawei

    2016-01-01

    The use of Bacillus subtilis in synthetic biology and metabolic engineering is highly desirable to take advantage of the unique metabolic pathways present in this organism. To do this, an evaluation of B. subtilis' intrinsic biological parts is required to determine the best strategies to accurately regulate metabolic circuits and expression of target proteins. The strengths of promoter candidates were evaluated by measuring relative fluorescence units of a green fluorescent protein reporter, integrated into B. subtilis' chromosome. A total of 84 predicted promoter sequences located upstream of different classes of proteins including heat shock proteins, cell-envelope proteins, and proteins resistant against toxic metals (based on similarity) and other kinds of genes were tested. The expression levels measured ranged from 0.0023 to 4.53-fold of the activity of the well-characterized strong promoter P43. No significant shifts were observed when strains, carrying different promoter candidates, were cultured at high temperature or in media with ethanol, but some strains showed increased activity when cultured under high osmotic pressure. Randomly selected promoter candidates were tested and found to activate transcription of thermostable β-galactosidase (bgaB) at a similar level, implying the ability of these sequences to function as promoter elements in multiple genetic contexts. In addition, selected promoters elevated the final production of both cytoplasmic bgaB and secreted protein α-amylase to about fourfold and twofold, respectively. The generated data allows a deeper understanding of B. subtilis' metabolism and will facilitate future work to develop this organism for synthetic biology. PMID:27380260

  18. Promoter Screening from Bacillus subtilis in Various Conditions Hunting for Synthetic Biology and Industrial Applications

    PubMed Central

    Fu, Gang; Chen, Jingqi; Li, Qinggang; Xie, Nengzhong; Zheng, Ping; Sun, Jibin; Zhang, Dawei

    2016-01-01

    The use of Bacillus subtilis in synthetic biology and metabolic engineering is highly desirable to take advantage of the unique metabolic pathways present in this organism. To do this, an evaluation of B. subtilis’ intrinsic biological parts is required to determine the best strategies to accurately regulate metabolic circuits and expression of target proteins. The strengths of promoter candidates were evaluated by measuring relative fluorescence units of a green fluorescent protein reporter, integrated into B. subtilis’ chromosome. A total of 84 predicted promoter sequences located upstream of different classes of proteins including heat shock proteins, cell-envelope proteins, and proteins resistant against toxic metals (based on similarity) and other kinds of genes were tested. The expression levels measured ranged from 0.0023 to 4.53-fold of the activity of the well-characterized strong promoter P43. No significant shifts were observed when strains, carrying different promoter candidates, were cultured at high temperature or in media with ethanol, but some strains showed increased activity when cultured under high osmotic pressure. Randomly selected promoter candidates were tested and found to activate transcription of thermostable β-galactosidase (bgaB) at a similar level, implying the ability of these sequences to function as promoter elements in multiple genetic contexts. In addition, selected promoters elevated the final production of both cytoplasmic bgaB and secreted protein α-amylase to about fourfold and twofold, respectively. The generated data allows a deeper understanding of B. subtilis’ metabolism and will facilitate future work to develop this organism for synthetic biology. PMID:27380260

  19. Tobacco industry price-subsidizing promotions may overcome the downward pressure of higher prices on initiation of regular smoking.

    PubMed

    Pierce, John P; Gilmer, Todd P; Lee, Lora; Gilpin, Elizabeth A; de Beyer, Joy; Messer, Karen

    2005-10-01

    Real cigarette prices in the US increased from the early 1980s to early 1990s. Holding all else equal, adolescent initiation of regular smoking should have declined during this period. Using national population-based surveys (n = 336 343) conducted in the 1990s, we present trends (early 1960s to mid-1990s) in the initiation of regular smoking among 14-17-year-old adolescents and 18-21-year-old young adults. We also present trends in consumer-price-index-adjusted cigarette price and tobacco-industry expenditures for price-subsidizing promotions. We relate price and price-subsidizing tobacco industry expenditures to trends in initiation in the two age groups, using autoregressive integrated moving average models (ARIMA). From the model results, we conclude that price-subsidizing promotions may provide the tobacco industry with an effective way to segment the market. That is, they effectively offer lower prices to population subgroups that are more price-sensitive (e.g. young smokers not yet addicted), countering the depressing effect of general price increases on smoking. Thus, we find that the relationship of cigarette price to smoking behavior is more complex than previously described. PMID:15791678

  20. Ectomycorrhizal symbiosis in vitro between Tricholoma matsutake and Pinus densiflora seedlings that resembles naturally occurring 'shiro'.

    PubMed

    Yamada, Akiyoshi; Maeda, Ken; Kobayashi, Hisayasu; Murata, Hitoshi

    2006-03-01

    We established an in vitro ectomycorrhizal symbiosis between Tricholoma matsutake and Pinus densiflora. Mycorrhiza formed in a substrate of Modified Norkrans' C medium and granite-based soil had features similar to those observed previously only in naturally occurring mycorrhizal system called 'shiro,' and promoted the growth of plants with smaller root/shoot ratios. The in vitro formation of 'shiro' is essential for the development of T. matsutake system to produce mushrooms and is useful for the propagation and plantation of the mycorrhizal seedlings.

  1. Study of cnidarian-algal symbiosis in the "omics" age.

    PubMed

    Meyer, Eli; Weis, Virginia M

    2012-08-01

    The symbiotic associations between cnidarians and dinoflagellate algae (Symbiodinium) support productive and diverse ecosystems in coral reefs. Many aspects of this association, including the mechanistic basis of host-symbiont recognition and metabolic interaction, remain poorly understood. The first completed genome sequence for a symbiotic anthozoan is now available (the coral Acropora digitifera), and extensive expressed sequence tag resources are available for a variety of other symbiotic corals and anemones. These resources make it possible to profile gene expression, protein abundance, and protein localization associated with the symbiotic state. Here we review the history of "omics" studies of cnidarian-algal symbiosis and the current availability of sequence resources for corals and anemones, identifying genes putatively involved in symbiosis across 10 anthozoan species. The public availability of candidate symbiosis-associated genes leaves the field of cnidarian-algal symbiosis poised for in-depth comparative studies of sequence diversity and gene expression and for targeted functional studies of genes associated with symbiosis. Reviewing the progress to date suggests directions for future investigations of cnidarian-algal symbiosis that include (i) sequencing of Symbiodinium, (ii) proteomic analysis of the symbiosome membrane complex, (iii) glycomic analysis of Symbiodinium cell surfaces, and (iv) expression profiling of the gastrodermal cells hosting Symbiodinium. PMID:22983032

  2. 76 FR 22757 - Softwood Lumber Research, Promotion, Consumer Education and Industry Information Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-22

    ... Register on October 1, 2010 (75 FR 61002). That rule provided for a 60-day comment period which ended on... referendum order. SUMMARY: This rule proposes a Softwood Lumber Research, Promotion, Consumer Education and.... Department of Agriculture (USDA) is conducting a referendum among eligible domestic softwood...

  3. Consequences of symbiosis for food web dynamics.

    PubMed

    Kooi, B W; Kuijper, L D J; Kooijman, S A L M

    2004-09-01

    Basic Lotka-Volterra type models in which mutualism (a type of symbiosis where the two populations benefit both) is taken into account, may give unbounded solutions. We exclude such behaviour using explicit mass balances and study the consequences of symbiosis for the long-term dynamic behaviour of a three species system, two prey and one predator species in the chemostat. We compose a theoretical food web where a predator feeds on two prey species that have a symbiotic relationships. In addition to a species-specific resource, the two prey populations consume the products of the partner population as well. In turn, a common predator forages on these prey populations. The temporal change in the biomass and the nutrient densities in the reactor is described by ordinary differential equations (ODE). Since products are recycled, the dynamics of these abiotic materials must be taken into account as well, and they are described by odes in a similar way as the abiotic nutrients. We use numerical bifurcation analysis to assess the long-term dynamic behaviour for varying degrees of symbiosis. Attractors can be equilibria, limit cycles and chaotic attractors depending on the control parameters of the chemostat reactor. These control parameters that can be experimentally manipulated are the nutrient density of the inflow medium and the dilution rate. Bifurcation diagrams for the three species web with a facultative symbiotic association between the two prey populations, are similar to that of a bi-trophic food chain; nutrient enrichment leads to oscillatory behaviour. Predation combined with obligatory symbiotic prey-interactions has a stabilizing effect, that is, there is stable coexistence in a larger part of the parameter space than for a bi-trophic food chain. However, combined with a large growth rate of the predator, the food web can persist only in a relatively small region of the parameter space. Then, two zero-pair bifurcation points are the organizing centers. In

  4. Advancing the health care supply chain and promoting leadership through strategic partnerships with industry.

    PubMed

    Motiwala, Sanober S; McLaughlin, Joan E; King, John; Hodgson, Brent; Hamilton, Michael

    2008-01-01

    While supply chain partnerships are common in the private industry, they are unique in health care. This article looks at the novel partnership between St. Michael's Hospital and Baxter Canada. By sharing information and working together, these organizations evaluated and tackled service disruptions caused by backorders. Their formal collaboration has resulted in a streamlined backorder management process, and more importantly, better and timelier patient care.

  5. Tax and Fiscal Policies for Promotion of Industrial EnergyEfficiency: A Survey of International Experience

    SciTech Connect

    Price, Lynn; Galitsky, Christina; Sinton, Jonathan; Worrell,Ernst; Graus, Wina

    2005-09-15

    The Energy Foundation's China Sustainable Energy Program (CSEP) has undertaken a major project investigating fiscal and tax policy options for stimulating energy efficiency and renewable energy development in China. This report, which is part of the sectoral sub-project studies on energy efficiency in industry, surveys international experience with tax and fiscal policies directed toward increasing investments in energy efficiency in the industrial sector. The report begins with an overview of tax and fiscal policies, including descriptions and evaluations of programs that use energy or energy-related carbon dioxide (CO2) taxes, pollution levies, public benefit charges, grants or subsidies, subsidized audits, loans, tax relief for specific technologies, and tax relief as part of an energy or greenhouse gas (GHG) emission tax or agreement scheme. Following the discussion of these individual policies, the report reviews experience with integrated programs found in two countries as well as with GHG emissions trading programs. The report concludes with a discussion of the best practices related to international experience with tax and fiscal policies to encourage investment in energy efficiency in industry.

  6. Metabolic constraints for a novel symbiosis

    PubMed Central

    Sørensen, Megan E. S.; Cameron, Duncan D.; Brockhurst, Michael A.; Wood, A. Jamie

    2016-01-01

    Ancient evolutionary events are difficult to study because their current products are derived forms altered by millions of years of adaptation. The primary endosymbiotic event formed the first photosynthetic eukaryote resulting in both plants and algae, with vast consequences for life on Earth. The evolutionary time that passed since this event means the dominant mechanisms and changes that were required are obscured. Synthetic symbioses such as the novel interaction between Paramecium bursaria and the cyanobacterium Synechocystis PC6803, recently established in the laboratory, permit a unique window on the possible early trajectories of this critical evolutionary event. Here, we apply metabolic modelling, using flux balance analysis (FBA), to predict the metabolic adaptations necessary for this previously free-living symbiont to transition to the endosymbiotic niche. By enforcing reciprocal nutrient trading, we are able to predict the most efficient exchange nutrients for both host and symbiont. During the transition from free-living to obligate symbiosis, it is likely that the trading parameters will change over time, which leads in our model to discontinuous changes in the preferred exchange nutrients. Our results show the applicability of FBA modelling to ancient evolutionary transitions driven by metabolic exchanges, and predict how newly established endosymbioses, governed by conflict, will differ from a well-developed one that has reached a mutual-benefit state. PMID:27069664

  7. A Symbiosis: Carbon Monitoring and Carbon Management

    NASA Astrophysics Data System (ADS)

    Macauley, M.

    2015-12-01

    "We measure what we value and value what we measure." This old dictum characterizes the usefulness of carbon monitoring in serving society, both in advancing research on carbon cycles and in applying new scientific knowledge to help carbon management. Many attempts to design policy for carbon management have been limited, ineffective, or otherwise unsuccessful in part due to inadequate capacity to observe carbon sources and sinks with sufficient measurement certainty and at appropriate spatial scale. Too often, policy designers fail to understand the complexities of carbon science and carbon researchers fail to align at least a portion of their science goals with policy requirements. The carbon monitoring systems research and applications activities under the auspices of the US National Aeronautics and Space Administration have significantly advanced both science and applications. To further this necessary symbiosis, this paper will synthesize current and prospective spatial and temporal requirements for emerging policy needs, discuss likely requirements for measurement certainty, and draw lessons from experiences in policies designed to monitor and manage other natural resources for which scientific research necessarily influenced policy design and effectiveness.

  8. Bacterial communities associated with the lichen symbiosis.

    PubMed

    Bates, Scott T; Cropsey, Garrett W G; Caporaso, J Gregory; Knight, Rob; Fierer, Noah

    2011-02-01

    Lichens are commonly described as a mutualistic symbiosis between fungi and "algae" (Chlorophyta or Cyanobacteria); however, they also have internal bacterial communities. Recent research suggests that lichen-associated microbes are an integral component of lichen thalli and that the classical view of this symbiotic relationship should be expanded to include bacteria. However, we still have a limited understanding of the phylogenetic structure of these communities and their variability across lichen species. To address these knowledge gaps, we used bar-coded pyrosequencing to survey the bacterial communities associated with lichens. Bacterial sequences obtained from four lichen species at multiple locations on rock outcrops suggested that each lichen species harbored a distinct community and that all communities were dominated by Alphaproteobacteria. Across all samples, we recovered numerous bacterial phylotypes that were closely related to sequences isolated from lichens in prior investigations, including those from a lichen-associated Rhizobiales lineage (LAR1; putative N(2) fixers). LAR1-related phylotypes were relatively abundant and were found in all four lichen species, and many sequences closely related to other known N(2) fixers (e.g., Azospirillum, Bradyrhizobium, and Frankia) were recovered. Our findings confirm the presence of highly structured bacterial communities within lichens and provide additional evidence that these bacteria may serve distinct functional roles within lichen symbioses.

  9. Metabolic constraints for a novel symbiosis.

    PubMed

    Sørensen, Megan E S; Cameron, Duncan D; Brockhurst, Michael A; Wood, A Jamie

    2016-03-01

    Ancient evolutionary events are difficult to study because their current products are derived forms altered by millions of years of adaptation. The primary endosymbiotic event formed the first photosynthetic eukaryote resulting in both plants and algae, with vast consequences for life on Earth. The evolutionary time that passed since this event means the dominant mechanisms and changes that were required are obscured. Synthetic symbioses such as the novel interaction between Paramecium bursaria and the cyanobacterium Synechocystis PC6803, recently established in the laboratory, permit a unique window on the possible early trajectories of this critical evolutionary event. Here, we apply metabolic modelling, using flux balance analysis (FBA), to predict the metabolic adaptations necessary for this previously free-living symbiont to transition to the endosymbiotic niche. By enforcing reciprocal nutrient trading, we are able to predict the most efficient exchange nutrients for both host and symbiont. During the transition from free-living to obligate symbiosis, it is likely that the trading parameters will change over time, which leads in our model to discontinuous changes in the preferred exchange nutrients. Our results show the applicability of FBA modelling to ancient evolutionary transitions driven by metabolic exchanges, and predict how newly established endosymbioses, governed by conflict, will differ from a well-developed one that has reached a mutual-benefit state. PMID:27069664

  10. Asian success stories in promoting energy efficiency in industry and building

    SciTech Connect

    Yang, Ming

    1996-12-31

    This article describes the program of the International Institute for Energy Conservation (IIEC), which has offices in Washington, Bangkok, Santiago, and London, in addition to staff in a number of other countries. The mission of this private organization is to promote the efficient use of energy as a tool for sustainable development by supporting the development of policies, technologies, and practices. Its focus is on energy efficiency, transportation systems, and renewable energy sources. Examples of specific program activities in Thailand, China, Philippines, Malaysia, Indonesia and Singapore are discussed.

  11. Promoting pollution prevention through community-industry dialogues: the good neighbor model in Minnesota.

    PubMed

    Murdock, Barbara Scott; Sexton, Ken

    2002-05-15

    This article examines five attempts by communities to promote pollution prevention through direct negotiations with local manufacturing plants. These projects were Good Neighbor Dialogues spearheaded by Citizens for a Better Environment-Minnesota, an environmental advocacy organization. Three community-company partnerships (a container plant, a foundry, and a cabinet manufacturer) were successful and two (a munitions plant and a petroleum refinery) were not. Successful dialogues all shared certain characteristics: the company was open to negotiating with the community; there was an effective "champion" within the company; a skilled, independent facilitator served as moderator; community participants received independent technical assistance; and both the company and community understood the value of cooperative environmental decision making. Results suggest that Good Neighbor Dialogues can, under the right settings and circumstances, be an effective mechanism for building social capital by fostering greater understanding and trust between companies and communities. They offer the prospect of community-company partnerships that promote pollution prevention and other environmental improvements, while at the same time reinforcing and amplifying traditional pollution control strategies. PMID:12038821

  12. Partnering with industry to promote compliance: The Texas EnviroMentor program

    SciTech Connect

    Watzlavick, P.

    1997-08-01

    The Texas Natural Resource Conservation Commission (TNRCC) Small Business Assistance Program (SBAP) is expanding its service by establishing Texas EnviroMentor, a cooperative effort linking government and business. Industry and legal professionals volunteer as EnviroMentors to help small businesses comply with environmental regulations. The EnviroMentor program can help businesses with permits, suggest ways to lower costs, and answer technical questions. Like all SBAP initiatives, Texas EnviroMentor is nonregulatory and confidential. Businesses wary of government assistant that might hesitate to work with the SBAP can use the program to seek help from private-sector volunteers. Nothing discussed during a company`s involvement with the EnviroMentors is shared with TNRCC enforcement divisions. The SBAP helps businesses understand and comply with environmental regulations. The SBAP provides technical assistance, pollution prevention information, advocacy, and industry-specific workshops. Staff members help businesses identify barrier to compliance and work to solve those problems before enforcement action occurs. Small businesses benefit from being able to call the program`s free hot line and get answers to questions about air, water, and waste rules.

  13. DELLA proteins regulate arbuscule formation in arbuscular mycorrhizal symbiosis

    PubMed Central

    Floss, Daniela S.; Levy, Julien G.; Lévesque-Tremblay, Véronique; Pumplin, Nathan; Harrison, Maria J.

    2013-01-01

    Most flowering plants are able to form endosymbioses with arbuscular mycorrhizal fungi. In this mutualistic association, the fungus colonizes the root cortex and establishes elaborately branched hyphae, called arbuscules, within the cortical cells. Arbuscule development requires the cellular reorganization of both symbionts, and the resulting symbiotic interface functions in nutrient exchange. A plant symbiosis signaling pathway controls the development of the symbiosis. Several components of the pathway have been identified, but transcriptional regulators that control downstream pathways for arbuscule formation are still unknown. Here we show that DELLA proteins, which are repressors of gibberellic acid (GA) signaling and function at the nexus of several signaling pathways, are required for arbuscule formation. Arbuscule formation is severely impaired in a Medicago truncatula Mtdella1/Mtdella2 double mutant; GA treatment of wild-type roots phenocopies the della double mutant, and a dominant DELLA protein (della1-Δ18) enables arbuscule formation in the presence of GA. Ectopic expression of della1-Δ18 suggests that DELLA activity in the vascular tissue and endodermis is sufficient to enable arbuscule formation in the inner cortical cells. In addition, expression of della1-Δ18 restores arbuscule formation in the symbiosis signaling pathway mutant cyclops/ipd3, indicating an intersection between DELLA and symbiosis signaling for arbuscule formation. GA signaling also influences arbuscule formation in monocots, and a Green Revolution wheat variety carrying dominant DELLA alleles shows enhanced colonization but a limited growth response to arbuscular mycorrhizal symbiosis. PMID:24297892

  14. DELLA proteins regulate arbuscule formation in arbuscular mycorrhizal symbiosis.

    PubMed

    Floss, Daniela S; Levy, Julien G; Lévesque-Tremblay, Véronique; Pumplin, Nathan; Harrison, Maria J

    2013-12-17

    Most flowering plants are able to form endosymbioses with arbuscular mycorrhizal fungi. In this mutualistic association, the fungus colonizes the root cortex and establishes elaborately branched hyphae, called arbuscules, within the cortical cells. Arbuscule development requires the cellular reorganization of both symbionts, and the resulting symbiotic interface functions in nutrient exchange. A plant symbiosis signaling pathway controls the development of the symbiosis. Several components of the pathway have been identified, but transcriptional regulators that control downstream pathways for arbuscule formation are still unknown. Here we show that DELLA proteins, which are repressors of gibberellic acid (GA) signaling and function at the nexus of several signaling pathways, are required for arbuscule formation. Arbuscule formation is severely impaired in a Medicago truncatula Mtdella1/Mtdella2 double mutant; GA treatment of wild-type roots phenocopies the della double mutant, and a dominant DELLA protein (della1-Δ18) enables arbuscule formation in the presence of GA. Ectopic expression of della1-Δ18 suggests that DELLA activity in the vascular tissue and endodermis is sufficient to enable arbuscule formation in the inner cortical cells. In addition, expression of della1-Δ18 restores arbuscule formation in the symbiosis signaling pathway mutant cyclops/ipd3, indicating an intersection between DELLA and symbiosis signaling for arbuscule formation. GA signaling also influences arbuscule formation in monocots, and a Green Revolution wheat variety carrying dominant DELLA alleles shows enhanced colonization but a limited growth response to arbuscular mycorrhizal symbiosis.

  15. Ectomycorrhizal symbiosis affects functional diversity of rhizosphere fluorescent pseudomonads.

    PubMed

    Frey-Klett, Pascale; Chavatte, Michaël; Clausse, Marie-Lise; Courrier, Sébastien; Le Roux, Christine; Raaijmakers, Jos; Martinotti, Maria Giovanna; Pierrat, Jean-Claude; Garbaye, Jean

    2005-01-01

    Here we characterized the effect of the ectomycorrhizal symbiosis on the genotypic and functional diversity of soil Pseudomonas fluorescens populations and analysed its possible consequences in terms of plant nutrition, development and health. Sixty strains of P. fluorescens were isolated from the bulk soil of a forest nursery, the ectomycorrhizosphere and the ectomycorrhizas of the Douglas fir (Pseudostuga menziesii) seedlings-Laccaria bicolor S238N. They were characterized in vitro with the following criteria: ARDRA, phosphate solubilization, siderophore, HCN and AIA production, genes of N2-fixation and antibiotic synthesis, in vitro confrontation with a range of phytopathogenic and ectomycorrhizal fungi, effect on the Douglas fir-L. bicolor symbiosis. For most of these criteria, we demonstrated that the ectomycorrhizosphere significantly structures the P. fluorescens populations and selects strains potentially beneficial to the symbiosis and to the plant. This prompts us to propose the ectomycorrhizal symbiosis as a true microbial complex where multitrophic interactions take place. Moreover it underlines the fact that this symbiosis has an indirect positive effect on plant growth, via its selective pressure on bacterial communities, in addition to its known direct positive effect. PMID:15720643

  16. Use of municipal incinerator bottom ash as sintering promoter in industrial ceramics.

    PubMed

    Barbieri, L; Corradi, A; Lancellotti, I; Manfredini, T

    2002-01-01

    The use of glassy frits obtained from municipal incinerator bottom ash and glass cullet, as sintering promoters in the production process of porcelainized stoneware, was investigated. The emphasis was on studying the similarities and differences with respect to the standard body. The characterization involved the application of several techniques: chemical analysis, X-ray powder diffraction, linear shrinkage during firing, water absorption, bending strength and spot resistance test. The results show that, the addition of these glassy frits in the body improve the characteristics of water absorption and spot resistance which is related to the absence of surface porosity originated by the glassy phase. Moreover, addition of glassy frits to the porcelanized stoneware body does not change significantly its bending strength. In the firing conditions used there is a slight worsening in the tiles planarity, while there is a significant modification of the color, which becomes darker with respect to the base body.

  17. An antimicrobial peptide essential for bacterial survival in the nitrogen-fixing symbiosis.

    PubMed

    Kim, Minsoo; Chen, Yuhui; Xi, Jiejun; Waters, Christopher; Chen, Rujin; Wang, Dong

    2015-12-01

    In the nitrogen-fixing symbiosis between legume hosts and rhizobia, the bacteria are engulfed by a plant cell membrane to become intracellular organelles. In the model legume Medicago truncatula, internalization and differentiation of Sinorhizobium (also known as Ensifer) meliloti is a prerequisite for nitrogen fixation. The host mechanisms that ensure the long-term survival of differentiating intracellular bacteria (bacteroids) in this unusual association are unclear. The M. truncatula defective nitrogen fixation4 (dnf4) mutant is unable to form a productive symbiosis, even though late symbiotic marker genes are expressed in mutant nodules. We discovered that in the dnf4 mutant, bacteroids can apparently differentiate, but they fail to persist within host cells in the process. We found that the DNF4 gene encodes NCR211, a member of the family of nodule-specific cysteine-rich (NCR) peptides. The phenotype of dnf4 suggests that NCR211 acts to promote the intracellular survival of differentiating bacteroids. The greatest expression of DNF4 was observed in the nodule interzone II-III, where bacteroids undergo differentiation. A translational fusion of DNF4 with GFP localizes to the peribacteroid space, and synthetic NCR211 prevents free-living S. meliloti from forming colonies, in contrast to mock controls, suggesting that DNF4 may interact with bacteroids directly or indirectly for its function. Our findings indicate that a successful symbiosis requires host effectors that not only induce bacterial differentiation, but also that maintain intracellular bacteroids during the host-symbiont interaction. The discovery of NCR211 peptides that maintain bacterial survival inside host cells has important implications for improving legume crops.

  18. An antimicrobial peptide essential for bacterial survival in the nitrogen-fixing symbiosis

    PubMed Central

    Kim, Minsoo; Chen, Yuhui; Xi, Jiejun; Waters, Christopher; Chen, Rujin; Wang, Dong

    2015-01-01

    In the nitrogen-fixing symbiosis between legume hosts and rhizobia, the bacteria are engulfed by a plant cell membrane to become intracellular organelles. In the model legume Medicago truncatula, internalization and differentiation of Sinorhizobium (also known as Ensifer) meliloti is a prerequisite for nitrogen fixation. The host mechanisms that ensure the long-term survival of differentiating intracellular bacteria (bacteroids) in this unusual association are unclear. The M. truncatula defective nitrogen fixation4 (dnf4) mutant is unable to form a productive symbiosis, even though late symbiotic marker genes are expressed in mutant nodules. We discovered that in the dnf4 mutant, bacteroids can apparently differentiate, but they fail to persist within host cells in the process. We found that the DNF4 gene encodes NCR211, a member of the family of nodule-specific cysteine-rich (NCR) peptides. The phenotype of dnf4 suggests that NCR211 acts to promote the intracellular survival of differentiating bacteroids. The greatest expression of DNF4 was observed in the nodule interzone II-III, where bacteroids undergo differentiation. A translational fusion of DNF4 with GFP localizes to the peribacteroid space, and synthetic NCR211 prevents free-living S. meliloti from forming colonies, in contrast to mock controls, suggesting that DNF4 may interact with bacteroids directly or indirectly for its function. Our findings indicate that a successful symbiosis requires host effectors that not only induce bacterial differentiation, but also that maintain intracellular bacteroids during the host–symbiont interaction. The discovery of NCR211 peptides that maintain bacterial survival inside host cells has important implications for improving legume crops. PMID:26598690

  19. Industry

    SciTech Connect

    Bernstein, Lenny; Roy, Joyashree; Delhotal, K. Casey; Harnisch, Jochen; Matsuhashi, Ryuji; Price, Lynn; Tanaka, Kanako; Worrell, Ernst; Yamba, Francis; Fengqi, Zhou; de la Rue du Can, Stephane; Gielen, Dolf; Joosen, Suzanne; Konar, Manaswita; Matysek, Anna; Miner, Reid; Okazaki, Teruo; Sanders, Johan; Sheinbaum Parado, Claudia

    2007-12-01

    This chapter addresses past, ongoing, and short (to 2010) and medium-term (to 2030) future actions that can be taken to mitigate GHG emissions from the manufacturing and process industries. Globally, and in most countries, CO{sub 2} accounts for more than 90% of CO{sub 2}-eq GHG emissions from the industrial sector (Price et al., 2006; US EPA, 2006b). These CO{sub 2} emissions arise from three sources: (1) the use of fossil fuels for energy, either directly by industry for heat and power generation or indirectly in the generation of purchased electricity and steam; (2) non-energy uses of fossil fuels in chemical processing and metal smelting; and (3) non-fossil fuel sources, for example cement and lime manufacture. Industrial processes also emit other GHGs, e.g.: (1) Nitrous oxide (N{sub 2}O) is emitted as a byproduct of adipic acid, nitric acid and caprolactam production; (2) HFC-23 is emitted as a byproduct of HCFC-22 production, a refrigerant, and also used in fluoroplastics manufacture; (3) Perfluorocarbons (PFCs) are emitted as byproducts of aluminium smelting and in semiconductor manufacture; (4) Sulphur hexafluoride (SF{sub 6}) is emitted in the manufacture, use and, decommissioning of gas insulated electrical switchgear, during the production of flat screen panels and semiconductors, from magnesium die casting and other industrial applications; (5) Methane (CH{sub 4}) is emitted as a byproduct of some chemical processes; and (6) CH{sub 4} and N{sub 2}O can be emitted by food industry waste streams. Many GHG emission mitigation options have been developed for the industrial sector. They fall into three categories: operating procedures, sector-wide technologies and process-specific technologies. A sampling of these options is discussed in Sections 7.2-7.4. The short- and medium-term potential for and cost of all classes of options are discussed in Section 7.5, barriers to the application of these options are addressed in Section 7.6 and the implication of

  20. Symbiosis-induced adaptation to oxidative stress.

    PubMed

    Richier, Sophie; Furla, Paola; Plantivaux, Amandine; Merle, Pierre-Laurent; Allemand, Denis

    2005-01-01

    Cnidarians in symbiosis with photosynthetic protists must withstand daily hyperoxic/anoxic transitions within their host cells. Comparative studies between symbiotic (Anemonia viridis) and non-symbiotic (Actinia schmidti) sea anemones show striking differences in their response to oxidative stress. First, the basal expression of SOD is very different. Symbiotic animal cells have a higher isoform diversity (number and classes) and a higher activity than the non-symbiotic cells. Second, the symbiotic animal cells of A. viridis also maintain unaltered basal values for cellular damage when exposed to experimental hyperoxia (100% O(2)) or to experimental thermal stress (elevated temperature +7 degrees C above ambient). Under such conditions, A. schmidti modifies its SOD activity significantly. Electrophoretic patterns diversify, global activities diminish and cell damage biomarkers increase. These data suggest symbiotic cells adapt to stress while non-symbiotic cells remain acutely sensitive. In addition to being toxic, high O(2) partial pressure (P(O(2))) may also constitute a preconditioning step for symbiotic animal cells, leading to an adaptation to the hyperoxic condition and, thus, to oxidative stress. Furthermore, in aposymbiotic animal cells of A. viridis, repression of some animal SOD isoforms is observed. Meanwhile, in cultured symbionts, new activity bands are induced, suggesting that the host might protect its zooxanthellae in hospite. Similar results have been observed in other symbiotic organisms, such as the sea anemone Aiptasia pulchella and the scleractinian coral Stylophora pistillata. Molecular or physical interactions between the two symbiotic partners may explain such variations in SOD activity and might confer oxidative stress tolerance to the animal host. PMID:15634847

  1. Ocean acidification alters fish-jellyfish symbiosis.

    PubMed

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

    2016-06-29

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

  2. Symbiosis-induced adaptation to oxidative stress.

    PubMed

    Richier, Sophie; Furla, Paola; Plantivaux, Amandine; Merle, Pierre-Laurent; Allemand, Denis

    2005-01-01

    Cnidarians in symbiosis with photosynthetic protists must withstand daily hyperoxic/anoxic transitions within their host cells. Comparative studies between symbiotic (Anemonia viridis) and non-symbiotic (Actinia schmidti) sea anemones show striking differences in their response to oxidative stress. First, the basal expression of SOD is very different. Symbiotic animal cells have a higher isoform diversity (number and classes) and a higher activity than the non-symbiotic cells. Second, the symbiotic animal cells of A. viridis also maintain unaltered basal values for cellular damage when exposed to experimental hyperoxia (100% O(2)) or to experimental thermal stress (elevated temperature +7 degrees C above ambient). Under such conditions, A. schmidti modifies its SOD activity significantly. Electrophoretic patterns diversify, global activities diminish and cell damage biomarkers increase. These data suggest symbiotic cells adapt to stress while non-symbiotic cells remain acutely sensitive. In addition to being toxic, high O(2) partial pressure (P(O(2))) may also constitute a preconditioning step for symbiotic animal cells, leading to an adaptation to the hyperoxic condition and, thus, to oxidative stress. Furthermore, in aposymbiotic animal cells of A. viridis, repression of some animal SOD isoforms is observed. Meanwhile, in cultured symbionts, new activity bands are induced, suggesting that the host might protect its zooxanthellae in hospite. Similar results have been observed in other symbiotic organisms, such as the sea anemone Aiptasia pulchella and the scleractinian coral Stylophora pistillata. Molecular or physical interactions between the two symbiotic partners may explain such variations in SOD activity and might confer oxidative stress tolerance to the animal host.

  3. Ocean acidification alters fish-jellyfish symbiosis.

    PubMed

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

    2016-06-29

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

  4. On Human Symbiosis and the Vicissitudes of Individuation. Infantile Psychosis, Volume 1.

    ERIC Educational Resources Information Center

    Mahler, Margaret S.

    The concepts of symbiosis and separation-individuation are explained, and the symbiosis theory of infantile psychosis is presented. Diagnostic considerations and clinical cases of child psychosis are reviewed; prototypes of mother-child interaction are described; and therapy is discussed. A summary of the symbiosis theory and a bibliography of…

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

    PubMed

    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.

  6. Evolving together: the biology of symbiosis, part 1

    PubMed Central

    2000-01-01

    Symbioses, prolonged associations between organisms often widely separated phylogenetically, are more common in biology than we once thought and have been neglected as a phenomenon worthy of study on its own merits. Extending along a dynamic continuum from antagonistic to cooperative and often involving elements of both antagonism and mutualism, symbioses involve pathogens, commensals, and mutualists interacting in myriad ways over the evolutionary history of the involved “partners.” In this first of 2 parts, some remarkable examples of symbiosis will be explored, from the coral-algal symbiosis and nitrogen fixation to the great diversity of dietary specializations enabled by the gastrointestinal microbiota of animals. PMID:16389385

  7. Genome of an arbuscular mycorrhizal fungus provides insight into the oldest plant symbiosis.

    PubMed

    Tisserant, Emilie; Malbreil, Mathilde; Kuo, Alan; Kohler, Annegret; Symeonidi, Aikaterini; Balestrini, Raffaella; Charron, Philippe; Duensing, Nina; Frei dit Frey, Nicolas; Gianinazzi-Pearson, Vivienne; Gilbert, Luz B; Handa, Yoshihiro; Herr, Joshua R; Hijri, Mohamed; Koul, Raman; Kawaguchi, Masayoshi; Krajinski, Franziska; Lammers, Peter J; Masclaux, Frederic G; Murat, Claude; Morin, Emmanuelle; Ndikumana, Steve; Pagni, Marco; Petitpierre, Denis; Requena, Natalia; Rosikiewicz, Pawel; Riley, Rohan; Saito, Katsuharu; San Clemente, Hélène; Shapiro, Harris; van Tuinen, Diederik; Bécard, Guillaume; Bonfante, Paola; Paszkowski, Uta; Shachar-Hill, Yair Y; Tuskan, Gerald A; Young, J Peter W; Young, Peter W; Sanders, Ian R; Henrissat, Bernard; Rensing, Stefan A; Grigoriev, Igor V; Corradi, Nicolas; Roux, Christophe; Martin, Francis

    2013-12-10

    The mutualistic symbiosis involving Glomeromycota, a distinctive phylum of early diverging Fungi, is widely hypothesized to have promoted the evolution of land plants during the middle Paleozoic. These arbuscular mycorrhizal fungi (AMF) perform vital functions in the phosphorus cycle that are fundamental to sustainable crop plant productivity. The unusual biological features of AMF have long fascinated evolutionary biologists. The coenocytic hyphae host a community of hundreds of nuclei and reproduce clonally through large multinucleated spores. It has been suggested that the AMF maintain a stable assemblage of several different genomes during the life cycle, but this genomic organization has been questioned. Here we introduce the 153-Mb haploid genome of Rhizophagus irregularis and its repertoire of 28,232 genes. The observed low level of genome polymorphism (0.43 SNP per kb) is not consistent with the occurrence of multiple, highly diverged genomes. The expansion of mating-related genes suggests the existence of cryptic sex-related processes. A comparison of gene categories confirms that R. irregularis is close to the Mucoromycotina. The AMF obligate biotrophy is not explained by genome erosion or any related loss of metabolic complexity in central metabolism, but is marked by a lack of genes encoding plant cell wall-degrading enzymes and of genes involved in toxin and thiamine synthesis. A battery of mycorrhiza-induced secreted proteins is expressed in symbiotic tissues. The present comprehensive repertoire of R. irregularis genes provides a basis for future research on symbiosis-related mechanisms in Glomeromycota.

  8. Genome of an arbuscular mycorrhizal fungus provides insight into the oldest plant symbiosis

    PubMed Central

    Tisserant, Emilie; Malbreil, Mathilde; Kuo, Alan; Kohler, Annegret; Symeonidi, Aikaterini; Balestrini, Raffaella; Charron, Philippe; Duensing, Nina; Frei dit Frey, Nicolas; Gianinazzi-Pearson, Vivienne; Gilbert, Luz B.; Handa, Yoshihiro; Herr, Joshua R.; Hijri, Mohamed; Koul, Raman; Kawaguchi, Masayoshi; Krajinski, Franziska; Lammers, Peter J.; Masclaux, Frederic G.; Murat, Claude; Morin, Emmanuelle; Ndikumana, Steve; Pagni, Marco; Petitpierre, Denis; Requena, Natalia; Rosikiewicz, Pawel; Riley, Rohan; Saito, Katsuharu; San Clemente, Hélène; Shapiro, Harris; van Tuinen, Diederik; Bécard, Guillaume; Bonfante, Paola; Paszkowski, Uta; Shachar-Hill, Yair Y.; Tuskan, Gerald A.; Young, J. Peter W.; Sanders, Ian R.; Henrissat, Bernard; Rensing, Stefan A.; Grigoriev, Igor V.; Corradi, Nicolas; Roux, Christophe; Martin, Francis

    2013-01-01

    The mutualistic symbiosis involving Glomeromycota, a distinctive phylum of early diverging Fungi, is widely hypothesized to have promoted the evolution of land plants during the middle Paleozoic. These arbuscular mycorrhizal fungi (AMF) perform vital functions in the phosphorus cycle that are fundamental to sustainable crop plant productivity. The unusual biological features of AMF have long fascinated evolutionary biologists. The coenocytic hyphae host a community of hundreds of nuclei and reproduce clonally through large multinucleated spores. It has been suggested that the AMF maintain a stable assemblage of several different genomes during the life cycle, but this genomic organization has been questioned. Here we introduce the 153-Mb haploid genome of Rhizophagus irregularis and its repertoire of 28,232 genes. The observed low level of genome polymorphism (0.43 SNP per kb) is not consistent with the occurrence of multiple, highly diverged genomes. The expansion of mating-related genes suggests the existence of cryptic sex-related processes. A comparison of gene categories confirms that R. irregularis is close to the Mucoromycotina. The AMF obligate biotrophy is not explained by genome erosion or any related loss of metabolic complexity in central metabolism, but is marked by a lack of genes encoding plant cell wall-degrading enzymes and of genes involved in toxin and thiamine synthesis. A battery of mycorrhiza-induced secreted proteins is expressed in symbiotic tissues. The present comprehensive repertoire of R. irregularis genes provides a basis for future research on symbiosis-related mechanisms in Glomeromycota. PMID:24277808

  9. Sea turtle symbiosis facilitates social monogamy in oceanic crabs via refuge size.

    PubMed

    Pfaller, Joseph B; Gil, Michael A

    2016-09-01

    The capacity for resource monopolization by individuals often dictates the size and composition of animal groups, and ultimately, the adoption of mating strategies. For refuge-dwelling animals, the ability (or inability) of individuals to monopolize refuges should depend on the relative size of the refuge. In theory, groups should be larger and more inclusive when refuges are large, and smaller and more exclusive when refuges are small, regardless of refuge type. We test this prediction by comparing the size and composition of groups of oceanic crabs (Planes minutus) living on plastic flotsam and loggerhead sea turtles. We found that (i) surface area of refuges (barnacle colonies on flotsam and supracaudal space on turtles) is a better predictor of crab number than total surface area and (ii) flotsam and turtles with similar refuge surface area host a similar number (1-2) and composition (adult male-female pairs) of crabs. These results indicate that group size and composition of refuge-dwelling animals are modulated by refuge size and the capacity for refuge monopolization. Moreover, these results suggest that sea turtle symbiosis facilitates social monogamy in oceanic crabs, providing insights into how symbiosis can promote specific mating strategies.

  10. Sea turtle symbiosis facilitates social monogamy in oceanic crabs via refuge size.

    PubMed

    Pfaller, Joseph B; Gil, Michael A

    2016-09-01

    The capacity for resource monopolization by individuals often dictates the size and composition of animal groups, and ultimately, the adoption of mating strategies. For refuge-dwelling animals, the ability (or inability) of individuals to monopolize refuges should depend on the relative size of the refuge. In theory, groups should be larger and more inclusive when refuges are large, and smaller and more exclusive when refuges are small, regardless of refuge type. We test this prediction by comparing the size and composition of groups of oceanic crabs (Planes minutus) living on plastic flotsam and loggerhead sea turtles. We found that (i) surface area of refuges (barnacle colonies on flotsam and supracaudal space on turtles) is a better predictor of crab number than total surface area and (ii) flotsam and turtles with similar refuge surface area host a similar number (1-2) and composition (adult male-female pairs) of crabs. These results indicate that group size and composition of refuge-dwelling animals are modulated by refuge size and the capacity for refuge monopolization. Moreover, these results suggest that sea turtle symbiosis facilitates social monogamy in oceanic crabs, providing insights into how symbiosis can promote specific mating strategies. PMID:27651538

  11. Arbuscular mycorrhizal symbiosis and active ingredients of medicinal plants: current research status and prospectives.

    PubMed

    Zeng, Yan; Guo, Lan-Ping; Chen, Bao-Dong; Hao, Zhi-Peng; Wang, Ji-Yong; Huang, Lu-Qi; Yang, Guang; Cui, Xiu-Ming; Yang, Li; Wu, Zhao-Xiang; Chen, Mei-Lan; Zhang, Yan

    2013-05-01

    Medicinal plants have been used world-wide for thousands of years and are widely recognized as having high healing but minor toxic side effects. The scarcity and increasing demand for medicinal plants and their products have promoted the development of artificial cultivation of medicinal plants. Currently, one of the prominent issues in medicinal cultivation systems is the unstable quality of the products. Arbuscular mycorrhiza (AM) affects secondary metabolism and the production of active ingredients of medicinal plants and thus influence the quality of herbal medicines. In this review, we have assembled, analyzed, and summarized the effects of AM symbioses on secondary metabolites of medicinal plants. We conclude that symbiosis of AM is conducive to favorable characteristics of medicinal plants, by improving the production and accumulation of important active ingredients of medicinal plants such as terpenes, phenols, and alkaloids, optimizing the composition of different active ingredients in medicinal plants and ultimately improving the quality of herbal materials. We are convinced that the AM symbiosis will benefit the cultivation of medicinal plants and improve the total yield and quality of herbal materials. Through this review, we hope to draw attention to the status and prospects of, and arouse more interest in, the research field of medicinal plants and mycorrhiza.

  12. The receptor kinase CERK1 has dual functions in symbiosis and immunity signalling.

    PubMed

    Zhang, Xiaowei; Dong, Wentao; Sun, Jongho; Feng, Feng; Deng, Yiwen; He, Zuhua; Oldroyd, Giles E D; Wang, Ertao

    2015-01-01

    The establishment of symbiotic interactions between mycorrhizal fungi, rhizobial bacteria and their legume hosts involves a common symbiosis signalling pathway. This signalling pathway is activated by Nod factors produced by rhizobia and these are recognised by the Nod factor receptors NFR1/LYK3 and NFR5/NFP. Mycorrhizal fungi produce lipochitooligosaccharides (LCOs) similar to Nod factors, as well as short-chain chitin oligomers (CO4/5), implying commonalities in signalling during mycorrhizal and rhizobial associations. Here we show that NFR1/LYK3, but not NFR5/NFP, is required for the establishment of the mycorrhizal interaction in legumes. NFR1/LYK3 is necessary for the recognition of mycorrhizal fungi and the activation of the symbiosis signalling pathway leading to induction of calcium oscillations and gene expression. Chitin oligosaccharides also act as microbe associated molecular patterns that promote plant immunity via similar LysM receptor-like kinases. CERK1 in rice has the highest homology to NFR1 and we show that this gene is also necessary for the establishment of the mycorrhizal interaction as well as for resistance to the rice blast fungus. Our results demonstrate that NFR1/LYK3/OsCERK1 represents a common receptor for chitooligosaccharide-based signals produced by mycorrhizal fungi, rhizobial bacteria (in legumes) and fungal pathogens. It would appear that mycorrhizal recognition has been conserved in multiple receptors across plant species, but additional diversification in certain plant species has defined other signals that this class of receptors can perceive.

  13. Quorum sensing in the squid-Vibrio symbiosis.

    PubMed

    Verma, Subhash C; Miyashiro, Tim

    2013-08-07

    Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization.

  14. Quorum Sensing in the Squid-Vibrio Symbiosis

    PubMed Central

    Verma, Subhash C.; Miyashiro, Tim

    2013-01-01

    Quorum sensing is an intercellular form of communication that bacteria use to coordinate group behaviors such as biofilm formation and the production of antibiotics and virulence factors. The term quorum sensing was originally coined to describe the mechanism underlying the onset of luminescence production in cultures of the marine bacterium Vibrio fischeri. Luminescence and, more generally, quorum sensing are important for V. fischeri to form a mutualistic symbiosis with the Hawaiian bobtail squid, Euprymna scolopes. The symbiosis is established when V. fischeri cells migrate via flagella-based motility from the surrounding seawater into a specialized structure injuvenile squid called the light organ. The cells grow to high cell densities within the light organ where the infection persists over the lifetime of the animal. A hallmark of a successful symbiosis is the luminescence produced by V. fischeri that camouflages the squid at night by eliminating its shadow within the water column. While the regulatory networks governing quorum sensing are critical for properly regulating V. fischeri luminescence within the squid light organ, they also regulate luminescence-independent processes during symbiosis. In this review, we discuss the quorum-sensing network of V. fischeri and highlight its impact at various stages during host colonization. PMID:23965960

  15. Signaling events during initiation of arbuscular mycorrhizal symbiosis.

    PubMed

    Schmitz, Alexa M; Harrison, Maria J

    2014-03-01

    Under nutrient-limiting conditions, plants will enter into symbiosis with arbuscular mycorrhizal (AM) fungi for the enhancement of mineral nutrient acquisition from the surrounding soil. AM fungi live in close, intracellular association with plant roots where they transfer phosphate and nitrogen to the plant in exchange for carbon. They are obligate fungi, relying on their host as their only carbon source. Much has been discovered in the last decade concerning the signaling events during initiation of the AM symbiosis, including the identification of signaling molecules generated by both partners. This signaling occurs through symbiosis-specific gene products in the host plant, which are indispensable for normal AM development. At the same time, plants have adapted complex mechanisms for avoiding infection by pathogenic fungi, including an innate immune response to general microbial molecules, such as chitin present in fungal cell walls. How it is that AM fungal colonization is maintained without eliciting a defensive response from the host is still uncertain. In this review, we present a summary of the molecular signals and their elicited responses during initiation of the AM symbiosis, including plant immune responses and their suppression.

  16. [HYDROBIOCENOSES--A MODEL SYSTEM OF ASSOCIATIVE SYMBIOSIS].

    PubMed

    Nemtseva, N V

    2015-01-01

    Evolutionary formed mechanisms, that preserve and support microorganism populations in any environmental conditions up to extreme, that are the base of survival strategy, were analyzed. Natural mechanisms, that support biodiversity and stability of ecosystems of natural water bodies, are shown to determine structuredness of hydrobiont communities by associative symbiosis type.

  17. Sugar for my honey: carbohydrate partitioning in ectomycorrhizal symbiosis.

    PubMed

    Nehls, Uwe; Grunze, Nina; Willmann, Martin; Reich, Marlis; Küster, Helge

    2007-01-01

    Simple, readily utilizable carbohydrates, necessary for growth and maintenance of large numbers of microbes are rare in forest soils. Among other types of mutualistic interactions, the formation of ectomycorrhizas, a symbiosis between tree roots and certain soil fungi, is a way to overcome nutrient and carbohydrate limitations typical for many forest ecosystems. Ectomycorrhiza formation is typical for trees in boreal and temperate forests of the northern hemisphere and alpine regions world-wide. The main function of this symbiosis is the exchange of fungus-derived nutrients for plant-derived carbohydrates, enabling the colonization of mineral nutrient-poor environments. In ectomycorrhizal symbiosis up to 1/3 of plant photoassimilates could be transferred toward the fungal partner. The creation of such a strong sink is directly related to the efficiency of fungal hexose uptake at the plant/fungus interface, a modulated fungal carbohydrate metabolism in the ectomycorrhiza, and the export of carbohydrates towards soil growing hyphae. However, not only the fungus but also the plant partner increase its expression of hexose importer genes at the plant/fungus interface. This increase in hexose uptake capacity of plant roots in combination with an increase in photosynthesis may explain how the plant deals with the growing fungal carbohydrate demand in symbiosis and how it can restrict this loss of carbohydrates under certain conditions to avoid fungal parasitism. PMID:17078984

  18. Current knowledge on the environmental fate, potential impact, and management of growth-promoting steroids used in the US beef cattle industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growth promoting steroids and steroid-like compounds (GPSC) used by the US beef cattle industry are potential contaminants to water resources. Manure generated in concentrated animal feeding operations contains GPSCs that may enter the environment. Several studies have focused on off-site impacts of...

  19. Pass the fruits and vegetables! A community-university-industry partnership promotes weight loss in African American women.

    PubMed

    Weerts, Sally E; Amoran, Alma

    2011-03-01

    This article describes a community-university-industry partnership to alleviate food insecurity while promoting weight loss. Twenty-one overweight African American women are randomly assigned to experimental or control groups. Each receives supermarket gift cards and brief health education monthly for 3 months. The experimental group buys fresh produce only, whereas the control group buys any groceries. Data on weight, body mass index (BMI), waist-hip circumferences, and dietary intake are collected at baseline and months 1 to 3. Nine (43%) have complete data. Quantitative data reveal that the experimental group have lost significantly more weight (-6, +4 lbs), significantly reduced BMI (-1, +0.7), and eat significantly more raw, fresh produce (1.29, 0.15 cups). A focus group held at month 4 is rich with the meanings of participating, eating "well," and forming new habits. A nutrient-dense diet that is calorically balanced is the hallmark of health and well-being and may be related to weight loss in new ways. However, this diet is not always affordable by those most in need of it. The unexpected outcome of a statistical relationship among consuming raw, freshly prepared produce, weight loss, and BMI reduction within 3 months is not altogether explainable. There are obvious benefits, however, to these outcomes that support the continuing study of the phenomenon.

  20. Enhanced production of L-sorbose in an industrial Gluconobacter oxydans strain by identification of a strong promoter based on proteomics analysis.

    PubMed

    Hu, Yudong; Wan, Hui; Li, Jianghua; Zhou, Jingwen

    2015-07-01

    Gluconobacter oxydans is capable of rapidly incomplete oxidation of many sugars and alcohols, which means the strain has great potential for industrial purposes. Strong promoters are one of the essential factors that can improve strain performance by overexpression of specific genes. In this study, a pipeline for screening strong promoters by proteomics analysis was established. Based on the procedure, a new strong promoter designated as P B932_2000 was identified in G. oxydans WSH-003. The promoter region was characterized based on known genome sequence information using BPROM. The strength of P B932_2000 was further assessed by analysis of enhanced green fluorescent protein (egfp) expression and comparison with egfp expression by two commonly used strong promoters, P E. coli_tufB and P G. oxydans_tufB . Both quantitative real-time PCR and fluorescence intensities for egfp gene expression showed that P B932_2000 promoter is stronger than the other two. Overexpression of D-sorbitol dehydrogenase (sldh) by P B932_2000 in G. oxydans WSH-003 enhanced the titer and productivity of L-sorbose synthesis from D-sorbitol by 12.0 % and 33.3 %, respectively. These results showed that proteomics analysis is an efficient way to identify strong promoters. The isolated promoter P B932_2000 could further facilitate the metabolic engineering of G. oxydans.

  1. The evolution of specificity in the legume-rhizobium symbiosis.

    PubMed

    Young, J P; Johnston, A W

    1989-11-01

    We know more about the partnership between legumes and their root-nodule bacteria than about any other symbiosis or any other plant-microbe interaction. In the light of recent research we are beginning to see details of an elaborate tapestry. The rhizobia are not a self-contained branch on the bacterial tree; their ancestry is intertwined with that of photosynthetic and pathogenic bacteria. Their host ranges, which vary enormously in breadth, overlap to form a tangled web of interconnections between plants and bacteria, and mechanisms of infection and nodule development are more diverse than we once thought. From genetic analysis of the bacteria we learn that specificity is not the province of special 'host-range determinants', but is affected by a wide range of genes with diverse modes of action. The symbiosis is a rich resource for evolutionary fact and speculation, but its complexity and diversity should warn us not to expect easy answers.

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

    PubMed

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

    2016-07-01

    A multidisciplinary approach, involving eco-physiological, morphometric, biochemical and molecular analyses, has been used to study the impact of two different AM fungi, i.e. Funneliformis mosseae and Rhizophagus intraradices, on tomato response to water stress. Overall, results show that AM symbiosis positively affects the tolerance to drought in tomato with a different plant response depending on the involved AM fungal species. PMID:27359066

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

    SciTech Connect

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

    2007-08-10

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

  4. Symbiosis increases coral tolerance to ocean acidification

    NASA Astrophysics Data System (ADS)

    Ohki, S.; Irie, T.; Inoue, M.; Shinmen, K.; Kawahata, H.; Nakamura, T.; Kato, A.; Nojiri, Y.; Suzuki, A.; Sakai, K.; van Woesik, R.

    2013-04-01

    Increasing the acidity of ocean waters will directly threaten calcifying marine organisms such as reef-building scleractinian corals, and the myriad of species that rely on corals for protection and sustenance. Ocean pH has already decreased by around 0.1 pH units since the beginning of the industrial revolution, and is expected to decrease by another 0.2-0.4 pH units by 2100. This study mimicked the pre-industrial, present, and near-future levels of pCO2 using a precise control system (±5% pCO2), to assess the impact of ocean acidification on the calcification of recently-settled primary polyps of Acropora digitifera, both with and without symbionts, and adult fragments with symbionts. The increase in pCO2 of 100 μatm between the pre-industrial period and the present had more effect on the calcification rate of adult A. digitifera than the anticipated future increases of several hundreds of micro-atmospheres of pCO2. The primary polyps with symbionts showed higher calcification rates than primary polyps without symbionts, suggesting that (i) primary polyps housing symbionts are more tolerant to near-future ocean acidification than organisms without symbionts, and (ii) corals acquiring symbionts from the environment (i.e. broadcasting species) will be more vulnerable to ocean acidification than corals that maternally acquire symbionts.

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

    SciTech Connect

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

    2005-03-01

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

  6. Evolution of symbiosis with resource allocation from fecundity to survival

    NASA Astrophysics Data System (ADS)

    Fukui, Shin

    2014-05-01

    Symbiosis is one of the most fundamental relationships between or among organisms and includes parasitism (which has negative effects on the fitness of the interacting partner), commensalism (no effect), and mutualism (positive effects). The effects of these interactions are usually assumed to influence a single component of a species' fitness, either survival or fecundity, even though in reality the interaction can simultaneously affect both of these components. I used a dual lattice model to investigate the process of evolution of mutualistic symbiosis in the presence of interactive effects on both survival and fecundity. I demonstrate that a positive effect on survival and a negative effect on fecundity are key to the establishment of mutualism. Furthermore, both the parasitic and the mutualistic behaviour must carry large costs for mutualism to evolve. This helps develop a new understanding of symbiosis as a function of resource allocation, in which resources are shifted from fecundity to survival. The simultaneous establishment of mutualism from parasitism never occurs in two species, but can do so in one of the species as long as the partner still behaves parasitically. This suggests that one of the altruistic behaviours in a mutualistic unit consisting of two species must originate as a parasitic behaviour.

  7. Evolution of symbiosis with resource allocation from fecundity to survival.

    PubMed

    Fukui, Shin

    2014-05-01

    Symbiosis is one of the most fundamental relationships between or among organisms and includes parasitism (which has negative effects on the fitness of the interacting partner), commensalism (no effect), and mutualism (positive effects). The effects of these interactions are usually assumed to influence a single component of a species' fitness, either survival or fecundity, even though in reality the interaction can simultaneously affect both of these components. I used a dual lattice model to investigate the process of evolution of mutualistic symbiosis in the presence of interactive effects on both survival and fecundity. I demonstrate that a positive effect on survival and a negative effect on fecundity are key to the establishment of mutualism. Furthermore, both the parasitic and the mutualistic behaviour must carry large costs for mutualism to evolve. This helps develop a new understanding of symbiosis as a function of resource allocation, in which resources are shifted from fecundity to survival. The simultaneous establishment of mutualism from parasitism never occurs in two species, but can do so in one of the species as long as the partner still behaves parasitically. This suggests that one of the altruistic behaviours in a mutualistic unit consisting of two species must originate as a parasitic behaviour.

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

    PubMed Central

    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, Rutchadaporn; Murooka, Yoshikatsu; Tajima, Shigeyuki; Simomura, Kenshiro; Nomura, Mika; Suzuki, Akihiro; Shimoda, Yoshikazu; Sioya, Kouki; Abe, Mikiko; Minamisawa, Kiwamu

    2004-01-01

    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, as well as nif-fix gene expression. In contrast, genes for cell wall synthesis, cell division, DNA replication, and flagella were strongly repressed in differentiated bacteroids. A highly upregulated gene in bacteroids, mlr5932 (encoding 1-aminocyclopropane-1-carboxylate deaminase), was disrupted and was confirmed to be involved in nodulation enhancement, indicating that disruption of highly expressed genes is a useful strategy for exploring novel gene functions in symbiosis. PMID:15060047

  9. Modulation of Symbiont Lipid A Signaling by Host Alkaline Phosphatases in the Squid-Vibrio Symbiosis

    PubMed Central

    Rader, Bethany A.; Kremer, Natacha; Apicella, Michael A.; Goldman, William E.; McFall-Ngai, Margaret J.

    2012-01-01

    ABSTRACT The synergistic activity of Vibrio fischeri lipid A and the peptidoglycan monomer (tracheal cytotoxin [TCT]) induces apoptosis in the superficial cells of the juvenile Euprymna scolopes light organ during the onset of the squid-vibrio symbiosis. Once the association is established in the epithelium-lined crypts of the light organ, the host degrades the symbiont’s constitutively produced TCT by the amidase activity of a peptidoglycan recognition protein (E. scolopes peptidoglycan recognition protein 2 [EsPGRP2]). In the present study, we explored the role of alkaline phosphatases in transforming the lipid A of the symbiont into a form that changes its signaling properties to host tissues. We obtained full-length open reading frames for two E. scolopes alkaline phosphatase (EsAP) mRNAs (esap1 and esap2); transcript levels suggested that the dominant light organ isoform is EsAP1. Levels of total EsAP activity increased with symbiosis, but only after the lipid A-dependent morphogenetic induction at 12 h, and were regulated over the day-night cycle. Inhibition of total EsAP activity impaired normal colonization and persistence by the symbiont. EsAP activity localized to the internal regions of the symbiotic juvenile light organ, including the lumina of the crypt spaces where the symbiont resides. These data provide evidence that EsAPs work in concert with EsPGRPs to change the signaling properties of bacterial products and thereby promote persistent colonization by the mutualistic symbiont. PMID:22550038

  10. Two putative-aquaporin genes are differentially expressed during arbuscular mycorrhizal symbiosis in Lotus japonicus

    PubMed Central

    2012-01-01

    Background Arbuscular mycorrhizas (AM) are widespread symbioses that provide great advantages to the plant, improving its nutritional status and allowing the fungus to complete its life cycle. Nevertheless, molecular mechanisms that lead to the development of AM symbiosis are not yet fully deciphered. Here, we have focused on two putative aquaporin genes, LjNIP1 and LjXIP1, which resulted to be upregulated in a transcriptomic analysis performed on mycorrhizal roots of Lotus japonicus. Results A phylogenetic analysis has shown that the two putative aquaporins belong to different functional families: NIPs and XIPs. Transcriptomic experiments have shown the independence of their expression from their nutritional status but also a close correlation with mycorrhizal and rhizobial interaction. Further transcript quantification has revealed a good correlation between the expression of one of them, LjNIP1, and LjPT4, the phosphate transporter which is considered a marker gene for mycorrhizal functionality. By using laser microdissection, we have demonstrated that one of the two genes, LjNIP1, is expressed exclusively in arbuscule-containing cells. LjNIP1, in agreement with its putative role as an aquaporin, is capable of transferring water when expressed in yeast protoplasts. Confocal analysis have demonstrated that eGFP-LjNIP1, under its endogenous promoter, accumulates in the inner membrane system of arbusculated cells. Conclusions Overall, the results have shown different functionality and expression specificity of two mycorrhiza-inducible aquaporins in L. japonicus. One of them, LjNIP1 can be considered a novel molecular marker of mycorrhizal status at different developmental stages of the arbuscule. At the same time, LjXIP1 results to be the first XIP family aquaporin to be transcriptionally regulated during symbiosis. PMID:23046713

  11. Induced gene expression in industrial Saccharomyces pastorianus var. carlsbergensis TUM 34/70: evaluation of temperature and ethanol inducible native promoters.

    PubMed

    Fischer, S; Engstler, C; Procopio, S; Becker, T

    2016-05-01

    Induced gene expression is an important trait in yeast metabolic engineering, but current regulations prevent the use of conventional expression systems, such as galactose and copper, in food and beverage fermentations. This article examines the suitability of temperature-inducible native promoters for use in the industrial yeast strain Saccharomyces pastorianus var. carlsbergensis TUM 34/70 under brewing conditions. Ten different promoters were cloned and characterized under varying temperature shifts and ethanol concentrations using a green fluorescent protein reporter. The activities of these promoters varied depending upon the stress conditions applied. A temperature shift to 4°C led to the highest fold changes of PSSA3, PUBI4 and PHSP104 by 5.4, 4.5 and 5.0, respectively. Ethanol shock at 24°C showed marked, concentration-dependent induction of the promoters. Here, PHSP104 showed its highest induction at ethanol concentrations between 4% (v/v) and 6% (v/v). The highest fold changes of PSSA3 and PUBI4 were found at 10% (v/v) ethanol. In comparison, the ethanol shock at a typical fermentation temperature (12°C) leads to lower induction patterns of these promoters. Taken together, the data show that three promoters (PHSP104, PUBI4 and PSSA3) have high potential for targeted gene expression in self-cloning brewing yeast using temperature shifts. PMID:26882929

  12. The Food Industry and Self-Regulation: Standards to Promote Success and to Avoid Public Health Failures

    PubMed Central

    Sharma, Lisa L.; Teret, Stephen P.

    2010-01-01

    Threatened by possible government regulation and critical public opinion, industries often undertake self-regulatory actions, issue statements of concern for public welfare, and assert that self-regulation is sufficient to protect the public. The food industry has made highly visible pledges to curtail children's food marketing, sell fewer unhealthy products in schools, and label foods in responsible ways. Ceding regulation to industry carries opportunities but is highly risky. In some industries (e.g., tobacco), self-regulation has been an abject failure, but in others (e.g., forestry and marine fisheries), it has been more successful. We examined food industry self-regulation in the context of other self-regulatory successes and failures and defined 8 standards that should be met if self-regulation is to be effective. PMID:20019306

  13. Arbuscular mycorrhizal symbiosis and osmotic adjustment in response to NaCl stress: a meta-analysis

    PubMed Central

    Augé, Robert M.; Toler, Heather D.; Saxton, Arnold M.

    2014-01-01

    Arbuscular mycorrhizal (AM) symbiosis can enhance plant resistance to NaCl stress in several ways. Two fundamental roles involve osmotic and ionic adjustment. By stimulating accumulation of solutes, the symbiosis can help plants sustain optimal water balance and diminish Na+ toxicity. The size of the AM effect on osmolytes has varied widely and is unpredictable. We conducted a meta-analysis to determine the size of the AM effect on 22 plant solute characteristics after exposure to NaCl and to examine how experimental conditions have influenced the AM effect. Viewed across studies, AM symbioses have had marked effects on plant K+, increasing root and shoot K+ concentrations by an average of 47 and 42%, respectively, and root and shoot K+/Na+ ratios by 47 and 58%, respectively. Among organic solutes, soluble carbohydrates have been most impacted, with AM-induced increases of 28 and 19% in shoots and roots. The symbiosis has had no consistent effect on several characteristics, including root glycine betaine concentration, root or shoot Cl− concentrations, leaf Ψπ, or shoot proline or polyamine concentrations. The AM effect has been very small for shoot Ca++ concentration and root concentrations of Na+, Mg++ and proline. Interpretations about AM-conferred benefits regarding these compounds may be best gauged within the context of the individual studies. Shoot and root K+/Na+ ratios and root proline concentration showed significant between-study heterogeneity, and we examined nine moderator variables to explore what might explain the differences in mycorrhizal effects on these parameters. Moderators with significant impacts included AM taxa, host type, presence or absence of AM growth promotion, stress severity, and whether NaCl constituted part or all of the experimental saline stress treatment. Meta-regression of shoot K+/Na+ ratio showed a positive response to root colonization, and root K+/Na+ ratio a negative response to time of exposure to NaCl. PMID:25368626

  14. Symbiosis between nitrogen-fixing bacteria and Medicago truncatula is not significantly affected by silver and silver sulfide nanomaterials.

    PubMed

    Judy, Jonathan D; Kirby, Jason K; McLaughlin, Mike J; McNear, David; Bertsch, Paul M

    2016-07-01

    Silver (Ag) engineered nanomaterials (ENMs) are being released into waste streams and are being discharged, largely as Ag2S aged-ENMs (a-ENMs), into agroecosystems receiving biosolids amendments. Recent research has demonstrated that biosolids containing an environmentally relevant mixture of ZnO, TiO2, and Ag ENMs and their transformation products, including Ag2S a-ENMs, disrupted the symbiosis between nitrogen-fixing bacteria and legumes. However, this study was unable to unequivocally determine which ENM or combination of ENMs and a-ENMs was responsible for the observed inhibition. Here, we examined further the effects of polyvinylpyrollidone (PVP) coated pristine Ag ENMs (PVP-Ag), Ag2S a-ENMs, and soluble Ag (as AgSO4) at 1, 10, and 100 mg Ag kg(-1) on the symbiosis between the legume Medicago truncatula and the nitrogen-fixing bacterium, Sinorhizobium melliloti in biosolids-amended soil. Nodulation frequency, nodule function, glutathione reductase production, and biomass were not significantly affected by any of the Ag treatments, even at 100 mg kg(-1), a concentration analogous to a worst-case scenario resulting from long-term, repeated biosolids amendments. Our results provide additional evidence that the disruption of the symbiosis between nitrogen-fixing bacteria and legumes in response to a mixture of ENMs in biosolids-amended soil reported previously may not be attributable to Ag ENMs or their transformation end-products. We anticipate these findings will provide clarity to regulators and industry regarding potential unintended consequences to terrestrial ecosystems resulting from of the use of Ag ENMs in consumer products. PMID:27149150

  15. Complaints, Complainants, and Rulings Regarding Drug Promotion in the United Kingdom and Sweden 2004–2012: A Quantitative and Qualitative Study of Pharmaceutical Industry Self-Regulation

    PubMed Central

    Zetterqvist, Anna V.; Merlo, Juan; Mulinari, Shai

    2015-01-01

    Background In many European countries, medicines promotion is governed by voluntary codes of practice administered by the pharmaceutical industry under its own system of self-regulation. Involvement of industry organizations in policing promotion has been proposed to deter illicit conduct, but few detailed studies on self-regulation have been carried out to date. The objective of this study was to examine the evidence for promotion and self-regulation in the UK and Sweden, two countries frequently cited as examples of effective self-regulation. Methods and Findings We performed a qualitative content analysis of documents outlining the constitutions and procedures of these two systems. We also gathered data from self-regulatory bodies on complaints, complainants, and rulings for the period 2004–2012. The qualitative analysis revealed similarities and differences between the countries. For example, self-regulatory bodies in both countries are required to actively monitor promotional items and impose sanctions on violating companies, but the range of sanctions is greater in the UK where companies may, for instance, be audited or publicly reprimanded. In total, Swedish and UK bodies ruled that 536 and 597 cases, respectively, were in breach, equating to an average of more than one case/week for each country. In Sweden, 430 (47%) complaints resulted from active monitoring, compared with only two complaints (0.2%) in the UK. In both countries, a majority of violations concerned misleading promotion. Charges incurred on companies averaged €447,000 and €765,000 per year in Sweden and the UK, respectively, equivalent to about 0.014% and 0.0051% of annual sales revenues, respectively. One hundred cases in the UK (17% of total cases in breach) and 101 (19%) in Sweden were highlighted as particularly serious. A total of 46 companies were ruled in breach of code for a serious offence at least once in the two countries combined (n = 36 in the UK; n = 27 in Sweden); seven

  16. The engine of the reef: photobiology of the coral-algal symbiosis.

    PubMed

    Roth, Melissa S

    2014-01-01

    Coral reef ecosystems thrive in tropical oligotrophic oceans because of the relationship between corals and endosymbiotic dinoflagellate algae called Symbiodinium. Symbiodinium convert sunlight and carbon dioxide into organic carbon and oxygen to fuel coral growth and calcification, creating habitat for these diverse and productive ecosystems. Light is thus a key regulating factor shaping the productivity, physiology, and ecology of the coral holobiont. Similar to all oxygenic photoautotrophs, Symbiodinium must safely harvest sunlight for photosynthesis and dissipate excess energy to prevent oxidative stress. Oxidative stress is caused by environmental stressors such as those associated with global climate change, and ultimately leads to breakdown of the coral-algal symbiosis known as coral bleaching. Recently, large-scale coral bleaching events have become pervasive and frequent threatening and endangering coral reefs. Because the coral-algal symbiosis is the biological engine producing the reef, the future of coral reef ecosystems depends on the ecophysiology of the symbiosis. This review examines the photobiology of the coral-algal symbiosis with particular focus on the photophysiological responses and timescales of corals and Symbiodinium. Additionally, this review summarizes the light environment and its dynamics, the vulnerability of the symbiosis to oxidative stress, the abiotic and biotic factors influencing photosynthesis, the diversity of the coral-algal symbiosis, and recent advances in the field. Studies integrating physiology with the developing "omics" fields will provide new insights into the coral-algal symbiosis. Greater physiological and ecological understanding of the coral-algal symbiosis is needed for protection and conservation of coral reefs.

  17. Impediment to symbiosis establishment between giant clams and Symbiodinium algae due to sterilization of seawater.

    PubMed

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

    2013-01-01

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

  18. Man-Computer Symbiosis Through Interactive Graphics: A Survey and Identification of Critical Research Areas.

    ERIC Educational Resources Information Center

    Knoop, Patricia A.

    The purpose of this report was to determine the research areas that appear most critical to achieving man-computer symbiosis. An operational definition of man-computer symbiosis was developed by: (1) reviewing and summarizing what others have said about it, and (2) attempting to distinguish it from other types of man-computer relationships. From…

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

    PubMed Central

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

    2013-01-01

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

  20. Persistent virus and addiction modules: an engine of symbiosis.

    PubMed

    Villarreal, Luis P

    2016-06-01

    The giant DNA viruses are highly prevalent and have a particular affinity for the lytic infection of unicellular eukaryotic host. The giant viruses can also be infected by inhibitory virophage which can provide lysis protection to their host. The combined protective and destructive action of such viruses can define a general model (PD) of virus-mediated host survival. Here, I present a general model for role such viruses play in the evolution of host symbiosis. By considering how virus mixtures can participate in addiction modules, I provide a functional explanation for persistence of virus derived genetic 'junk' in their host genomic habitats. PMID:27039268

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

    PubMed

    Duhamel, Marie; Vandenkoornhuyse, Philippe

    2013-11-01

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

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

    NASA Astrophysics Data System (ADS)

    Weiss, Achim

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

  3. Public/private sector cooperation to promote industrial energy efficiency: Allied partners and the US Department of Energy

    SciTech Connect

    McKane, Aimee; Cockrill, Chris; Tutterow, Vestal; Radspieler, Anthony

    2003-05-18

    Since 1996, the US Department of Energy's Office of Industrial Technologies (USDOE) has been involved in a unique voluntary collaboration with industry called the Allied Partner program. Initially developed under the Motor Challenge program, the partnership concept continues as a central element of USDOE's BestPractices, which in 2001 integrated all of USDOE's near-term industrial program offerings including those in motors, compressed air, pump, fan, process heating and steam systems. Partnerships are sought with end use industrial companies as well as equipment suppliers and manufacturers, utilities, consultants, and state agencies that have extensive existing relationships with industrial customers. Partners are neither paid nor charged a fee for participation. Since the inception of Allied Partners, the assumption has been that these relationships could serve as the foundation for conveying a system energy-efficiency message to many more industrial facilities than could be reached through a typical government-to-end-user program model. An independent evaluation of the Motor Challenge program, reported at the last EEMODS conference, attributed US $16.9 million or nearly 67 percent of the total annual program energy savings to the efforts of Allied Partners in the first three years of operation. A recent evaluation of the Compressed Air Challenger, which grew out of the former Motor Challenger program, attribute additional energy savings from compressed air training alone at US $12.1 million per year. Since the reorganization under BestPractices, the Allied Partner program has been reshaped to extend the impact of all BestPractices program activities. This new model is more ambitious than the former Motor Challenge program concerning the level of collaborative activities negotiated with Allied Partners. This paper describes in detail two new types of program initiatives involving Allied Partners: Qualified Specialist Training and Energy Events. The Qualified

  4. Effects of multiple climate change factors on the tall fescue-fungal endophyte symbiosis: infection frequency and tissue chemistry.

    SciTech Connect

    Brosi, Glade; McCulley, Rebecca L; Bush, L P; Nelson, Jim A; Classen, Aimee T; Norby, Richard J

    2011-01-01

    Climate change (altered CO{sub 2}, warming, and precipitation) may affect plant-microbial interactions, such as the Lolium arundinaceum-Neotyphodium coenophialum symbiosis, to alter future ecosystem structure and function. To assess this possibility, tall fescue tillers were collected from an existing climate manipulation experiment in a constructed old-field community in Tennessee (USA). Endophyte infection frequency (EIF) was determined, and infected (E+) and uninfected (E-) tillers were analysed for tissue chemistry. The EIF of tall fescue was higher under elevated CO{sub 2} (91% infected) than with ambient CO{sub 2} (81%) but was not affected by warming or precipitation treatments. Within E+ tillers, elevated CO{sub 2} decreased alkaloid concentrations of both ergovaline and loline, by c. 30%; whereas warming increased loline concentrations 28% but had no effect on ergovaline. Independent of endophyte infection, elevated CO{sub 2} reduced concentrations of nitrogen, cellulose, hemicellulose, and lignin. These results suggest that elevated CO{sub 2}, more than changes in temperature or precipitation, may promote this grass-fungal symbiosis, leading to higher EIF in tall fescue in old-field communities. However, as all three climate factors are likely to change in the future, predicting the symbiotic response and resulting ecological consequences may be difficult and dependent on the specific atmospheric and climatic conditions encountered.

  5. The symbiont side of symbiosis: do microbes really benefit?

    PubMed Central

    Garcia, Justine R.; Gerardo, Nicole M.

    2014-01-01

    Microbial associations are integral to all eukaryotes. Mutualism, the interaction of two species for the benefit of both, is an important aspect of microbial associations, with evidence that multicellular organisms in particular benefit from microbes. However, the microbe’s perspective has largely been ignored, and it is unknown whether most microbial symbionts benefit from their associations with hosts. It has been presumed that microbial symbionts receive host-derived nutrients or a competition-free environment with reduced predation, but there have been few empirical tests, or even critical assessments, of these assumptions. We evaluate these hypotheses based on available evidence, which indicate reduced competition and predation are not universal benefits for symbionts. Some symbionts do receive nutrients from their host, but this has not always been linked to a corresponding increase in symbiont fitness. We recommend experiments to test symbiont fitness using current experimental systems of symbiosis and detail considerations for other systems. Incorporating symbiont fitness into symbiosis research will provide insight into the evolution of mutualistic interactions and cooperation in general. PMID:25309530

  6. Genes conserved for arbuscular mycorrhizal symbiosis identified through phylogenomics.

    PubMed

    Bravo, Armando; York, Thomas; Pumplin, Nathan; Mueller, Lukas A; Harrison, Maria J

    2016-01-01

    Arbuscular mycorrhizal symbiosis (AMS), a widespread mutualistic association of land plants and fungi(1), is predicted to have arisen once, early in the evolution of land plants(2-4). Consistent with this notion, several genes required for AMS have been conserved throughout evolution(5) and their symbiotic functions preserved, at least between monocot and dicot plants(6,7). Despite its significance, knowledge of the plants' genetic programme for AMS is limited. To date, most genes required for AMS have been found through commonalities with the evolutionarily younger nitrogen-fixing Rhizobium legume symbiosis (RLS)(8) or by reverse genetic analyses of differentially expressed candidate genes(9). Large sequence-indexed insertion mutant collections and recent genome editing technologies have vastly increased the power of reverse genetics but selection of candidate genes, from the thousands of genes that change expression during AMS, remains an arbitrary process. Here, we describe a phylogenomics approach to identify genes whose evolutionary history predicts conservation for AMS and we demonstrate the accuracy of the predictions through reverse genetics analysis. Phylogenomics analysis of 50 plant genomes resulted in 138 genes from Medicago truncatula predicted to function in AMS. This includes 15 genes with known roles in AMS. Additionally, we demonstrate that mutants in six previously uncharacterized AMS-conserved genes are all impaired in AMS. Our results demonstrate that phylogenomics is an effective strategy to identify a set of evolutionarily conserved genes required for AMS. PMID:27249190

  7. An ancient tripartite symbiosis of plants, ants and scale insects.

    PubMed

    Ueda, Shouhei; Quek, Swee-Peck; Itioka, Takao; Inamori, Keita; Sato, Yumiko; Murase, Kaori; Itino, Takao

    2008-10-22

    In the Asian tropics, a conspicuous radiation of Macaranga plants is inhabited by obligately associated Crematogaster ants tending Coccus (Coccidae) scale insects, forming a tripartite symbiosis. Recent phylogenetic studies have shown that the plants and the ants have been codiversifying over the past 16-20 million years (Myr). The prevalence of coccoids in ant-plant mutualisms suggest that they play an important role in the evolution of ant-plant symbioses. To determine whether the scale insects were involved in the evolutionary origin of the mutualism between Macaranga and Crematogaster, we constructed a cytochrome oxidase I (COI) gene phylogeny of the scale insects collected from myrmecophytic Macaranga and estimated their time of origin based on a COI molecular clock. The minimum age of the associated Coccus was estimated to be half that of the ants, at 7-9Myr, suggesting that they were latecomers in the evolutionary history of the symbiosis. Crematogaster mitochondrial DNA (mtDNA) lineages did not exhibit specificity towards Coccus mtDNA lineages, and the latter was not found to be specific towards Macaranga taxa, suggesting that patterns of associations in the scale insects are dictated by opportunity rather than by specialized adaptations to host plant traits.

  8. Arsenic effect on the model crop symbiosis Bradyrhizobium-soybean.

    PubMed

    Talano, Melina A; Cejas, Romina B; González, Paola S; Agostini, Elizabeth

    2013-02-01

    Soybean (Glycine max) is often being cultivated in soils with moderate to high arsenic (As) concentrations or under irrigation with As contaminated groundwater. The purpose of this study was to determine the effect of As on soybean germination, development and nodulation in soybean-Bradyrhizobium japonicum E109 symbiosis, as a first-step approach to evaluate the impact of As on soybean production. Semi-hydroponic assays were conducted using soybean seedlings inoculated and non-inoculated with B. japonicum E109 and treated with arsenate or arsenite. Soybean germination and development, at early stage of growth, were significantly reduced from 10 μM arsenate or arsenite. This also was seen for soybean seedlings inoculated with B. japonicum mainly with arsenite where, in addition, the number of effective nodules was reduced, despite that the microorganism tolerated the metalloid. This minor nodulation could be due to a reduced motility (swarming and swimming) of the microorganism in presence of As. Arsenic concentration in roots was about 250-times higher than in shoots. Transference coefficient values indicated that As translocation to aerial parts was low and As accumulated mainly in roots, without significant differences between inoculated and non-inoculated plants. The presence of As restricted soybean-B. japonicum symbiosis and hence, the efficiency of most used commercial inoculants for soybean. Thus, water and/or soils containing As would negatively impact on soybean production, even in plants inoculated with B. japonicum E109.

  9. Aphids evolved novel secreted proteins for symbiosis with bacterial endosymbiont.

    PubMed

    Shigenobu, Shuji; Stern, David L

    2013-01-01

    Aphids evolved novel cells, called bacteriocytes, that differentiate specifically to harbour the obligatory mutualistic endosymbiotic bacteria Buchnera aphidicola. The genome of the host aphid Acyrthosiphon pisum contains many orphan genes that display no similarity with genes found in other sequenced organisms, prompting us to hypothesize that some of these orphan genes are related to lineage-specific traits, such as symbiosis. We conducted deep sequencing of bacteriocytes mRNA followed by whole mount in situ hybridizations of over-represented transcripts encoding aphid-specific orphan proteins. We identified a novel class of genes that encode small proteins with signal peptides, which are often cysteine-rich, that are over-represented in bacteriocytes. These genes are first expressed at a developmental time point coincident with the incorporation of symbionts strictly in the cells that contribute to the bacteriocyte and this bacteriocyte-specific expression is maintained throughout the aphid's life. The expression pattern suggests that recently evolved secretion proteins act within bacteriocytes, perhaps to mediate the symbiosis with beneficial bacterial partners, which is reminiscent of the evolution of novel cysteine-rich secreted proteins of leguminous plants that regulate nitrogen-fixing endosymbionts.

  10. A Promotion Program of Academic-Industrial Collaboration with Active and Joint Participation by Technical College Students Utilizing the Support Program for Contemporary Educational Needs

    NASA Astrophysics Data System (ADS)

    Furusaki, Tsuyoshi; Ueda, Shigeta; Kojima, Yoichiro; Ikeda, Shin-Ichi; Abe, Tsukasa; Yoshizawa, Kousuke; Tada, Mitsuhiro

    Since 2005, Tomakomai National College of Technology has been conducting “A Promotion Program of Academic-Industrial Collaboration with Active and Joint Participation by Technical College Students” , in which the students actively challenged to resolve technical problems of local companies through internships and graduation researches. This project was adopted as part of the Support Program for Contemporary Educational Needs by the Ministry of Education, Culture, Sports, Science and Technology. It has been revealed that the program is practical and effective engineering education for the students, i.e. “Future Engineers” . In addition, it leads to the revitalization of local companies which carried out collaborative researches with the participating students.

  11. Building an Entrepreneurial University in Brazil: The Role and Potential of University-Industry Linkages in Promoting Regional Economic Development

    ERIC Educational Resources Information Center

    Amaral, Marcelo; Ferreira, Andre; Teodoro, Pitias

    2011-01-01

    This study is part of a broader research project, conducted by the Triple Helix Research Group--Brazil, focusing on university-industry-government linkages in the state of Rio de Janeiro. The case study reported here is that of the Regional University of Volta Redonda: the aim was to develop an understanding of how a regional university can be…

  12. Discarded oranges and brewer's spent grains as promoting ingredients for microbial growth by submerged and solid state fermentation of agro-industrial waste mixtures.

    PubMed

    Aggelopoulos, Theodoros; Bekatorou, Argyro; Pandey, Ashok; Kanellaki, Maria; Koutinas, Athanasios A

    2013-08-01

    The exploitation of various agro-industrial wastes for microbial cell mass production of Kluyveromyces marxianus, kefir, and Saccharomyces cerevisiae is reported in the present investigation. Specifically, the promotional effect of whole orange pulp on cell growth in mixtures consisting of cheese whey, molasses, and potato pulp in submerged fermentation processes was examined. A 2- to 3-fold increase of cell mass was observed in the presence of orange pulp. Likewise, the promotional effect of brewer's spent grains on cell growth in solid state fermentation of mixtures of whey, molasses, potato pulp, malt spent rootlets, and orange pulp was examined. The cell mass was increased by 3-fold for K. marxianus and 2-fold for S. cerevisiae in the presence of these substrates, proving their suitability for single-cell protein production without the need for extra nutrients. Cell growth kinetics were also studied by measurements of cell counts at various time intervals at different concentrations of added orange pulp. The protein content of the fermented substrates was increased substantially, indicating potential use of mixed agro-industrial wastes of negligible cost, as protein-enriched livestock feed, achieving at the same time creation of added value and waste minimization. PMID:23780341

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

    PubMed

    López-Baena, Francisco J; Ruiz-Sainz, José E; Rodríguez-Carvajal, Miguel A; Vinardell, José M

    2016-01-01

    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. PMID:27213334

  14. Lipopolysaccharide mutants of Rhizobium meliloti are not defective in symbiosis

    SciTech Connect

    Clover, R.H.; Kieber, J.; Signer, E.R. )

    1989-07-01

    Mutants of Rhizobium meliloti selected primarily for bacteriophage resistance fall into 13 groups. Mutants in the four best-characterized groups (class A, lpsB, lpsC, and class D), which map to the rhizobial chromosome, appear to affect lipopolysaccharide (LPS) as judged by the reactivity with monoclonal antibodies and behavior on sodium dodecyl sulfate-polyacrylamide gels of extracted LPS. Mutations in all 13 groups, in an otherwise wild-type genetic background, are Fix{sup +} on alfalfa. This suggests that LPS does not play a major role in symbiosis. Mutations in lpsB, however, are Fix{sup {minus}} in one particular genetic background, evidently because of the cumulative effect of several independent background mutations. In addition, an auxotrophic mutation evidently equivalent to Escherichia coli carAB is Fix{sup {minus}} on alfalfa.

  15. Nuclear energy and waste management pyroprocess for system symbiosis

    NASA Astrophysics Data System (ADS)

    Ogawa, Toru; Minato, Kazuo; Okamoto, Yoshihiro; Nishihara, Kenji

    2007-01-01

    The actinide management has become a key issue in nuclear energy. Recovering and fissioning transuranium elements reduce the long-term proliferation risks and the environmental burden. The better way of waste management will be made by system symbiosis: a combination of light-water reactor and fast reactor and/or accelerator-driven transmutation system should be sought. The new recycling technology should be able to achieve good economy with smaller plants, which can process fuels from different types of reactors on a common technical basis. Ease in handling the higher heat load of transuranium nuclides is also important. Pyroprocesses with the use of molten salts are regarded as the strong candidate for such recycling technology. In JAEA, the first laboratory for the high-temperature chemistry of Am and Cm has been established. The fundamental data will be combined with the computer code for predicting the molten-salts electrolytic processes.

  16. Long-distance transport of signals during symbiosis

    PubMed Central

    Xie, Zhi-Ping; Illana, Antonio

    2011-01-01

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

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

    PubMed Central

    López-Baena, Francisco J.; Ruiz-Sainz, José E.; Rodríguez-Carvajal, Miguel A.; Vinardell, José M.

    2016-01-01

    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. PMID:27213334

  18. Making the Most of Omics for Symbiosis Research

    PubMed Central

    Chaston, J.; Douglas, A.E.

    2012-01-01

    Omics, including genomics, proteomics and metabolomics, enable us to explain symbioses in terms of the underlying molecules and their interactions. The central task is to transform molecular catalogs of genes, metabolites etc. into a dynamic understanding of symbiosis function. We review four exemplars of omics studies that achieve this goal, through defined biological questions relating to metabolic integration and regulation of animal-microbial symbioses, the genetic autonomy of bacterial symbionts, and symbiotic protection of animal hosts from pathogens. As omic datasets become increasingly complex, computationally-sophisticated downstream analyses are essential to reveal interactions not evident to visual inspection of the data. We discuss two approaches, phylogenomics and transcriptional clustering, that can divide the primary output of omics studies – long lists of factors – into manageable subsets, and we describe how they have been applied to analyze large datasets and generate testable hypotheses. PMID:22983030

  19. The DOE s In-Plant Training (INPLT) Model to Promote Energy Efficiency in the Industrial Sector

    SciTech Connect

    Alkadi, Nasr E; Nimbalkar, Sachin U; De Fontaine, Mr. Andre; Schoeneborn, Fred C

    2013-01-01

    In-Plant Training (INPLT) is a new model for developing energy efficiency expertise within the US manufacturing companies participating in the U.S. Department of Energy s (DOE s) Better Buildings, Better Plants Program-a nationwide initiative to drive a 25% reduction in industrial energy intensity in 10 years. INPLTs are designed to fill a market niche by providing hands on training in a real world manufacturing plant environment. Through INPLTs, participants from multiple manufacturing plants, supply chains, utilities, and other external stakeholders learn how to conduct energy assessments, use energy analysis tools to analyze energy saving opportunities, develop energy management systems, and implement energy savings projects. Typical INPLT events are led by DOE-certified Energy Experts and range from 2-4 days. Topics discussed include: identification of cross-cutting or system specific opportunities; introduction to ISO 50001 Energy Management Systems; and energy project implementation and replication. This model is flexible, and can be tailored to suit the needs of specific industries. The INPLTs are a significant departure from the traditional single plant energy assessment model previously employed by DOE. INPLTs shift the focus from the concept of a single-plant s energy profile to a broader focus on training and capacity building among multiple industrial participants. The objective is to enable trainees to identify, quantify, implement and replicate future energy saving projects without continued external assistance. This paper discusses the INPLT model and highlights some of the initial outcomes from the successfully delivered INPLTs and the overall impact in terms of numbers of plants/participants trained, impacted energy footprints, and potential replication of identified opportunities.

  20. Species specificity of symbiosis and secondary metabolism in ascidians

    PubMed Central

    Tianero, Ma Diarey B; Kwan, Jason C; Wyche, Thomas P; Presson, Angela P; Koch, Michael; Barrows, Louis R; Bugni, Tim S; Schmidt, Eric W

    2015-01-01

    Ascidians contain abundant, diverse secondary metabolites, which are thought to serve a defensive role and which have been applied to drug discovery. It is known that bacteria in symbiosis with ascidians produce several of these metabolites, but very little is known about factors governing these ‘chemical symbioses'. To examine this phenomenon across a wide geographical and species scale, we performed bacterial and chemical analyses of 32 different ascidians, mostly from the didemnid family from Florida, Southern California and a broad expanse of the tropical Pacific Ocean. Bacterial diversity analysis showed that ascidian microbiomes are highly diverse, and this diversity does not correlate with geographical location or latitude. Within a subset of species, ascidian microbiomes are also stable over time (R=−0.037, P-value=0.499). Ascidian microbiomes and metabolomes contain species-specific and location-specific components. Location-specific bacteria are found in low abundance in the ascidians and mostly represent strains that are widespread. Location-specific metabolites consist largely of lipids, which may reflect differences in water temperature. By contrast, species-specific bacteria are mostly abundant sequenced components of the microbiomes and include secondary metabolite producers as major components. Species-specific chemicals are dominated by secondary metabolites. Together with previous analyses that focused on single ascidian species or symbiont type, these results reveal fundamental properties of secondary metabolic symbiosis. Different ascidian species have established associations with many different bacterial symbionts, including those known to produce toxic chemicals. This implies a strong selection for this property and the independent origin of secondary metabolite-based associations in different ascidian species. The analysis here streamlines the connection of secondary metabolite to producing bacterium, enabling further biological and

  1. Lichen Symbiosis: Nature's High Yielding Machines for Induced Hydrogen Production

    PubMed Central

    Papazi, Aikaterini; Kastanaki, Elizabeth; Pirintsos, Stergios; Kotzabasis, Kiriakos

    2015-01-01

    Hydrogen is a promising future energy source. Although the ability of green algae to produce hydrogen has long been recognized (since 1939) and several biotechnological applications have been attempted, the greatest obstacle, being the O2-sensitivity of the hydrogenase enzyme, has not yet been overcome. In the present contribution, 75 years after the first report on algal hydrogen production, taking advantage of a natural mechanism of oxygen balance, we demonstrate high hydrogen yields by lichens. Lichens have been selected as the ideal organisms in nature for hydrogen production, since they consist of a mycobiont and a photobiont in symbiosis. It has been hypothesized that the mycobiont’s and photobiont’s consumption of oxygen (increase of COX and AOX proteins of mitochondrial respiratory pathways and PTOX protein of chrolorespiration) establishes the required anoxic conditions for the activation of the phycobiont’s hydrogenase in a closed system. Our results clearly supported the above hypothesis, showing that lichens have the ability to activate appropriate bioenergetic pathways depending on the specific incubation conditions. Under light conditions, they successfully use the PSII-dependent and the PSII-independent pathways (decrease of D1 protein and parallel increase of PSaA protein) to transfer electrons to hydrogenase, while under dark conditions, lichens use the PFOR enzyme and the dark fermentative pathway to supply electrons to hydrogenase. These advantages of lichen symbiosis in combination with their ability to survive in extreme environments (while in a dry state) constitute them as unique and valuable hydrogen producing natural factories and pave the way for future biotechnological applications. PMID:25826211

  2. Lichen symbiosis: nature's high yielding machines for induced hydrogen production.

    PubMed

    Papazi, Aikaterini; Kastanaki, Elizabeth; Pirintsos, Stergios; Kotzabasis, Kiriakos

    2015-01-01

    Hydrogen is a promising future energy source. Although the ability of green algae to produce hydrogen has long been recognized (since 1939) and several biotechnological applications have been attempted, the greatest obstacle, being the O2-sensitivity of the hydrogenase enzyme, has not yet been overcome. In the present contribution, 75 years after the first report on algal hydrogen production, taking advantage of a natural mechanism of oxygen balance, we demonstrate high hydrogen yields by lichens. Lichens have been selected as the ideal organisms in nature for hydrogen production, since they consist of a mycobiont and a photobiont in symbiosis. It has been hypothesized that the mycobiont's and photobiont's consumption of oxygen (increase of COX and AOX proteins of mitochondrial respiratory pathways and PTOX protein of chrolorespiration) establishes the required anoxic conditions for the activation of the phycobiont's hydrogenase in a closed system. Our results clearly supported the above hypothesis, showing that lichens have the ability to activate appropriate bioenergetic pathways depending on the specific incubation conditions. Under light conditions, they successfully use the PSII-dependent and the PSII-independent pathways (decrease of D1 protein and parallel increase of PSaA protein) to transfer electrons to hydrogenase, while under dark conditions, lichens use the PFOR enzyme and the dark fermentative pathway to supply electrons to hydrogenase. These advantages of lichen symbiosis in combination with their ability to survive in extreme environments (while in a dry state) constitute them as unique and valuable hydrogen producing natural factories and pave the way for future biotechnological applications.

  3. Lichen symbiosis: nature's high yielding machines for induced hydrogen production.

    PubMed

    Papazi, Aikaterini; Kastanaki, Elizabeth; Pirintsos, Stergios; Kotzabasis, Kiriakos

    2015-01-01

    Hydrogen is a promising future energy source. Although the ability of green algae to produce hydrogen has long been recognized (since 1939) and several biotechnological applications have been attempted, the greatest obstacle, being the O2-sensitivity of the hydrogenase enzyme, has not yet been overcome. In the present contribution, 75 years after the first report on algal hydrogen production, taking advantage of a natural mechanism of oxygen balance, we demonstrate high hydrogen yields by lichens. Lichens have been selected as the ideal organisms in nature for hydrogen production, since they consist of a mycobiont and a photobiont in symbiosis. It has been hypothesized that the mycobiont's and photobiont's consumption of oxygen (increase of COX and AOX proteins of mitochondrial respiratory pathways and PTOX protein of chrolorespiration) establishes the required anoxic conditions for the activation of the phycobiont's hydrogenase in a closed system. Our results clearly supported the above hypothesis, showing that lichens have the ability to activate appropriate bioenergetic pathways depending on the specific incubation conditions. Under light conditions, they successfully use the PSII-dependent and the PSII-independent pathways (decrease of D1 protein and parallel increase of PSaA protein) to transfer electrons to hydrogenase, while under dark conditions, lichens use the PFOR enzyme and the dark fermentative pathway to supply electrons to hydrogenase. These advantages of lichen symbiosis in combination with their ability to survive in extreme environments (while in a dry state) constitute them as unique and valuable hydrogen producing natural factories and pave the way for future biotechnological applications. PMID:25826211

  4. Harnessing mosquito-Wolbachia symbiosis for vector and disease control.

    PubMed

    Bourtzis, Kostas; Dobson, Stephen L; Xi, Zhiyong; Rasgon, Jason L; Calvitti, Maurizio; Moreira, Luciano A; Bossin, Hervé C; Moretti, Riccardo; Baton, Luke Anthony; Hughes, Grant L; Mavingui, Patrick; Gilles, Jeremie R L

    2014-04-01

    Mosquito species, members of the genera Aedes, Anopheles and Culex, are the major vectors of human pathogens including protozoa (Plasmodium sp.), filariae and of a variety of viruses (causing dengue, chikungunya, yellow fever, West Nile). There is lack of efficient methods and tools to treat many of the diseases caused by these major human pathogens, since no efficient vaccines or drugs are available; even in malaria where insecticide use and drug therapies have reduced incidence, 219 million cases still occurred in 2010. Therefore efforts are currently focused on the control of vector populations. Insecticides alone are insufficient to control mosquito populations since reduced susceptibility and even resistance is being observed more and more frequently. There is also increased concern about the toxic effects of insecticides on non-target (even beneficial) insect populations, on humans and the environment. During recent years, the role of symbionts in the biology, ecology and evolution of insect species has been well-documented and has led to suggestions that they could potentially be used as tools to control pests and therefore diseases. Wolbachia is perhaps the most renowned insect symbiont, mainly due to its ability to manipulate insect reproduction and to interfere with major human pathogens thus providing new avenues for pest control. We herein present recent achievements in the field of mosquito-Wolbachia symbiosis with an emphasis on Aedes albopictus. We also discuss how Wolbachia symbiosis can be harnessed for vector control as well as the potential to combine the sterile insect technique and Wolbachia-based approaches for the enhancement of population suppression programs. PMID:24252486

  5. Unfolding the secrets of coral–algal symbiosis

    PubMed Central

    Rosic, Nedeljka; Ling, Edmund Yew Siang; Chan, Chon-Kit Kenneth; Lee, Hong Ching; Kaniewska, Paulina; Edwards, David; Dove, Sophie; Hoegh-Guldberg, Ove

    2015-01-01

    Dinoflagellates from the genus Symbiodinium form a mutualistic symbiotic relationship with reef-building corals. Here we applied massively parallel Illumina sequencing to assess genetic similarity and diversity among four phylogenetically diverse dinoflagellate clades (A, B, C and D) that are commonly associated with corals. We obtained more than 30 000 predicted genes for each Symbiodinium clade, with a majority of the aligned transcripts corresponding to sequence data sets of symbiotic dinoflagellates and <2% of sequences having bacterial or other foreign origin. We report 1053 genes, orthologous among four Symbiodinium clades, that share a high level of sequence identity to known proteins from the SwissProt (SP) database. Approximately 80% of the transcripts aligning to the 1053 SP genes were unique to Symbiodinium species and did not align to other dinoflagellates and unrelated eukaryotic transcriptomes/genomes. Six pathways were common to all four Symbiodinium clades including the phosphatidylinositol signaling system and inositol phosphate metabolism pathways. The list of Symbiodinium transcripts common to all four clades included conserved genes such as heat shock proteins (Hsp70 and Hsp90), calmodulin, actin and tubulin, several ribosomal, photosynthetic and cytochrome genes and chloroplast-based heme-containing cytochrome P450, involved in the biosynthesis of xanthophylls. Antioxidant genes, which are important in stress responses, were also preserved, as were a number of calcium-dependent and calcium/calmodulin-dependent protein kinases that may play a role in the establishment of symbiosis. Our findings disclose new knowledge about the genetic uniqueness of symbiotic dinoflagellates and provide a list of homologous genes important for the foundation of coral–algal symbiosis. PMID:25343511

  6. Harnessing mosquito-Wolbachia symbiosis for vector and disease control.

    PubMed

    Bourtzis, Kostas; Dobson, Stephen L; Xi, Zhiyong; Rasgon, Jason L; Calvitti, Maurizio; Moreira, Luciano A; Bossin, Hervé C; Moretti, Riccardo; Baton, Luke Anthony; Hughes, Grant L; Mavingui, Patrick; Gilles, Jeremie R L

    2014-04-01

    Mosquito species, members of the genera Aedes, Anopheles and Culex, are the major vectors of human pathogens including protozoa (Plasmodium sp.), filariae and of a variety of viruses (causing dengue, chikungunya, yellow fever, West Nile). There is lack of efficient methods and tools to treat many of the diseases caused by these major human pathogens, since no efficient vaccines or drugs are available; even in malaria where insecticide use and drug therapies have reduced incidence, 219 million cases still occurred in 2010. Therefore efforts are currently focused on the control of vector populations. Insecticides alone are insufficient to control mosquito populations since reduced susceptibility and even resistance is being observed more and more frequently. There is also increased concern about the toxic effects of insecticides on non-target (even beneficial) insect populations, on humans and the environment. During recent years, the role of symbionts in the biology, ecology and evolution of insect species has been well-documented and has led to suggestions that they could potentially be used as tools to control pests and therefore diseases. Wolbachia is perhaps the most renowned insect symbiont, mainly due to its ability to manipulate insect reproduction and to interfere with major human pathogens thus providing new avenues for pest control. We herein present recent achievements in the field of mosquito-Wolbachia symbiosis with an emphasis on Aedes albopictus. We also discuss how Wolbachia symbiosis can be harnessed for vector control as well as the potential to combine the sterile insect technique and Wolbachia-based approaches for the enhancement of population suppression programs.

  7. Species specificity of symbiosis and secondary metabolism in ascidians.

    PubMed

    Tianero, Ma Diarey B; Kwan, Jason C; Wyche, Thomas P; Presson, Angela P; Koch, Michael; Barrows, Louis R; Bugni, Tim S; Schmidt, Eric W

    2015-03-01

    Ascidians contain abundant, diverse secondary metabolites, which are thought to serve a defensive role and which have been applied to drug discovery. It is known that bacteria in symbiosis with ascidians produce several of these metabolites, but very little is known about factors governing these 'chemical symbioses'. To examine this phenomenon across a wide geographical and species scale, we performed bacterial and chemical analyses of 32 different ascidians, mostly from the didemnid family from Florida, Southern California and a broad expanse of the tropical Pacific Ocean. Bacterial diversity analysis showed that ascidian microbiomes are highly diverse, and this diversity does not correlate with geographical location or latitude. Within a subset of species, ascidian microbiomes are also stable over time (R=-0.037, P-value=0.499). Ascidian microbiomes and metabolomes contain species-specific and location-specific components. Location-specific bacteria are found in low abundance in the ascidians and mostly represent strains that are widespread. Location-specific metabolites consist largely of lipids, which may reflect differences in water temperature. By contrast, species-specific bacteria are mostly abundant sequenced components of the microbiomes and include secondary metabolite producers as major components. Species-specific chemicals are dominated by secondary metabolites. Together with previous analyses that focused on single ascidian species or symbiont type, these results reveal fundamental properties of secondary metabolic symbiosis. Different ascidian species have established associations with many different bacterial symbionts, including those known to produce toxic chemicals. This implies a strong selection for this property and the independent origin of secondary metabolite-based associations in different ascidian species. The analysis here streamlines the connection of secondary metabolite to producing bacterium, enabling further biological and

  8. Unfolding the secrets of coral-algal symbiosis.

    PubMed

    Rosic, Nedeljka; Ling, Edmund Yew Siang; Chan, Chon-Kit Kenneth; Lee, Hong Ching; Kaniewska, Paulina; Edwards, David; Dove, Sophie; Hoegh-Guldberg, Ove

    2015-04-01

    Dinoflagellates from the genus Symbiodinium form a mutualistic symbiotic relationship with reef-building corals. Here we applied massively parallel Illumina sequencing to assess genetic similarity and diversity among four phylogenetically diverse dinoflagellate clades (A, B, C and D) that are commonly associated with corals. We obtained more than 30,000 predicted genes for each Symbiodinium clade, with a majority of the aligned transcripts corresponding to sequence data sets of symbiotic dinoflagellates and <2% of sequences having bacterial or other foreign origin. We report 1053 genes, orthologous among four Symbiodinium clades, that share a high level of sequence identity to known proteins from the SwissProt (SP) database. Approximately 80% of the transcripts aligning to the 1053 SP genes were unique to Symbiodinium species and did not align to other dinoflagellates and unrelated eukaryotic transcriptomes/genomes. Six pathways were common to all four Symbiodinium clades including the phosphatidylinositol signaling system and inositol phosphate metabolism pathways. The list of Symbiodinium transcripts common to all four clades included conserved genes such as heat shock proteins (Hsp70 and Hsp90), calmodulin, actin and tubulin, several ribosomal, photosynthetic and cytochrome genes and chloroplast-based heme-containing cytochrome P450, involved in the biosynthesis of xanthophylls. Antioxidant genes, which are important in stress responses, were also preserved, as were a number of calcium-dependent and calcium/calmodulin-dependent protein kinases that may play a role in the establishment of symbiosis. Our findings disclose new knowledge about the genetic uniqueness of symbiotic dinoflagellates and provide a list of homologous genes important for the foundation of coral-algal symbiosis.

  9. Restoring balance to industry-academia relationships in an era of institutional financial conflicts of interest: promoting research while maintaining trust.

    PubMed

    Johns, Michael M E; Barnes, Mark; Florencio, Patrik S

    2003-02-12

    Economic partnerships between industry and academia accelerate medical innovation and enhance patient access to medical advances, but such partnerships have sometimes eroded public trust in the research enterprise. There is particular risk for conflict of interest when economic partnerships extend beyond a university's corporate interests to involve institutional decision makers. Institutions and institutional decision makers should fully disclose industry-related financial interests and relationships. Without legitimate justification for such interests, individuals should divest themselves from these interests or recuse themselves from responsibility for research oversight. Management of institutional partnerships also might entail the physical separation of certain facilities, the placement of restrictions on information shared between investment and research staffs, and provision of oversight by independent review panels made up of persons who have expertise in intellectual property, finance, and research, but who are not financially or otherwise dependent on the institution. Through these means, it is possible to restore balance to industry-academia relationships, thereby promoting progress while maintaining public trust in research. PMID:12585953

  10. Beyond Food Promotion: A Systematic Review on the Influence of the Food Industry on Obesity-Related Dietary Behaviour among Children.

    PubMed

    Sonntag, Diana; Schneider, Sarah; Mdege, Noreen; Ali, Shehzad; Schmidt, Burkhard

    2015-10-16

    An increased consumption of energy-dense, nutrient-poor food and beverages as a result of a changing obesogenic environment contributes substantially to the increasing prevalence of childhood overweight and obesity. This paper reviews the nature and extent of food industry influences which expose children to commercial influences and thus might affect unhealthy dietary behaviour and finally contributes to obesity. A systematic search of nine electronic databases (including PubMed, PsycINFO, EconLit) and reference lists of original studies and reviews using key search terms identified 1900 articles. Of these only thirty-six articles met the inclusion and quality criteria. A narrative synthesis of the reviewed studies revealed six key obesogenic environments by which the food industry possibly influences obesity-related dietary behaviours in young children. These were schools, retailers, mass media "television", mass media "internet", home and promotional campaigns. Identifying these obesogenic environments is critical for monitoring and controlling the food industry, the development of effective environmental-level interventions to prevent childhood overweight and obesity and to identify knowledge gaps to be addressed in future research to support informed decisions of policy makers.

  11. Beyond Food Promotion: A Systematic Review on the Influence of the Food Industry on Obesity-Related Dietary Behaviour among Children

    PubMed Central

    Sonntag, Diana; Schneider, Sarah; Mdege, Noreen; Ali, Shehzad; Schmidt, Burkhard

    2015-01-01

    An increased consumption of energy-dense, nutrient-poor food and beverages as a result of a changing obesogenic environment contributes substantially to the increasing prevalence of childhood overweight and obesity. This paper reviews the nature and extent of food industry influences which expose children to commercial influences and thus might affect unhealthy dietary behaviour and finally contributes to obesity. A systematic search of nine electronic databases (including PubMed, PsycINFO, EconLit) and reference lists of original studies and reviews using key search terms identified 1900 articles. Of these only thirty-six articles met the inclusion and quality criteria. A narrative synthesis of the reviewed studies revealed six key obesogenic environments by which the food industry possibly influences obesity-related dietary behaviours in young children. These were schools, retailers, mass media “television”, mass media “internet”, home and promotional campaigns. Identifying these obesogenic environments is critical for monitoring and controlling the food industry, the development of effective environmental-level interventions to prevent childhood overweight and obesity and to identify knowledge gaps to be addressed in future research to support informed decisions of policy makers. PMID:26501319

  12. Beyond Food Promotion: A Systematic Review on the Influence of the Food Industry on Obesity-Related Dietary Behaviour among Children.

    PubMed

    Sonntag, Diana; Schneider, Sarah; Mdege, Noreen; Ali, Shehzad; Schmidt, Burkhard

    2015-10-01

    An increased consumption of energy-dense, nutrient-poor food and beverages as a result of a changing obesogenic environment contributes substantially to the increasing prevalence of childhood overweight and obesity. This paper reviews the nature and extent of food industry influences which expose children to commercial influences and thus might affect unhealthy dietary behaviour and finally contributes to obesity. A systematic search of nine electronic databases (including PubMed, PsycINFO, EconLit) and reference lists of original studies and reviews using key search terms identified 1900 articles. Of these only thirty-six articles met the inclusion and quality criteria. A narrative synthesis of the reviewed studies revealed six key obesogenic environments by which the food industry possibly influences obesity-related dietary behaviours in young children. These were schools, retailers, mass media "television", mass media "internet", home and promotional campaigns. Identifying these obesogenic environments is critical for monitoring and controlling the food industry, the development of effective environmental-level interventions to prevent childhood overweight and obesity and to identify knowledge gaps to be addressed in future research to support informed decisions of policy makers. PMID:26501319

  13. Media(ted) fabrications: how the science-media symbiosis helped 'sell' cord banking.

    PubMed

    Michelle, Carolyn

    2006-01-01

    This paper considers the problematic role of the science-media symbiosis in the dissemination of misleading and emotionally manipulative information regarding services offered by CordBank, New Zealand's only umbilical cord blood banking facility. As this case study illustrates, the growing reliance of health and science reporters on the knowledge capital of medical specialists, biogenetic researchers, and scientists potentially enhances the ability of 'expert' sources to set the agenda for media representations of emerging medical and scientific developments, and may undermine the editorial independence of journalists and editors, many of whom in this case failed to critically evaluate deeply problematic claims regarding the current and future benefits of cord banking. Heavy reliance on established media frames of anecdotal personalization and technoboosterism also reinforced a proscience journalistic culture in which claims by key sources were uncritically reiterated and amplified, with journalistic assessments of the value of cord banking emphasizing potential benefits for individual consumers. It is argued that use of these media frames potentially detracts from due consideration of the broader social, ethical, legal, and health implications of emerging biomedical developments, along with the professional, personal, and increasingly also financial interests at stake in their public promotion, given the growing commercialization of biogenetic technologies. PMID:16808425

  14. Full establishment of arbuscular mycorrhizal symbiosis in rice occurs independently of enzymatic jasmonate biosynthesis.

    PubMed

    Gutjahr, Caroline; Siegler, Heike; Haga, Ken; Iino, Moritoshi; Paszkowski, Uta

    2015-01-01

    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 μM 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. PMID:25860838

  15. Symbiosis theory-directed green synthesis of silver nanoparticles and their application in infected wound healing

    PubMed Central

    Wen, Lu; Zeng, Pei; Zhang, Liping; Huang, Wenli; Wang, Hui; Chen, Gang

    2016-01-01

    In this study, silver nanoparticles (AgNPs) were synthesized for the first time using an antibacterial endophytic fungus of Chinese medicinal herb Orchidantha chinensis, which has anti-inflammatory and antimicrobial activities. The AgNPs were analyzed by various characterization techniques to reveal their morphology, chemical composition, and stability. Also, the relationship between Chinese medicinal herbs, endophytic fungi, and the property of AgNPs was investigated for the first time. Interestingly, an experiment performed in this study revealed the proteins produced by the endophytic fungus to be capped on the nanoparticles, which led to an increase in the stability of spherical and polydispersed AgNPs with low aggregation for over 6 months. More importantly, further study demonstrated that the AgNPs possessed superior antibacterial activity and effectively promoted wound healing. Altogether, the biosynthesis of active AgNPs using the endophytic fungus from Chinese medicinal herb based on the symbiosis theory is simple, eco-friendly, and promising. PMID:27358563

  16. Arbuscular mycorrhiza Symbiosis Induces a Major Transcriptional Reprogramming of the Potato SWEET Sugar Transporter Family.

    PubMed

    Manck-Götzenberger, Jasmin; Requena, Natalia

    2016-01-01

    Biotrophic microbes feeding on plants must obtain carbon from their hosts without killing the cells. The symbiotic Arbuscular mycorrhizal (AM) fungi colonizing plant roots do so by inducing major transcriptional changes in the host that ultimately also reprogram the whole carbon partitioning of the plant. AM fungi obtain carbohydrates from the root cortex apoplast, in particular from the periarbuscular space that surrounds arbuscules. However, the mechanisms by which cortical cells export sugars into the apoplast for fungal nutrition are unknown. Recently a novel type of sugar transporter, the SWEET, able to perform not only uptake but also efflux from cells was identified. Plant SWEETs have been shown to be involved in the feeding of pathogenic microbes and are, therefore, good candidates to play a similar role in symbiotic associations. Here we have carried out the first phylogenetic and expression analyses of the potato SWEET family and investigated its role during mycorrhiza symbiosis. The potato genome contains 35 SWEETs that cluster into the same four clades defined in Arabidopsis. Colonization of potato roots by the AM fungus Rhizophagus irregularis imposes major transcriptional rewiring of the SWEET family involving, only in roots, changes in 22 of the 35 members. None of the SWEETs showed mycorrhiza-exclusive induction and most of the 12 induced genes belong to the putative hexose transporters of clade I and II, while only two are putative sucrose transporters from clade III. In contrast, most of the repressed transcripts (10) corresponded to clade III SWEETs. Promoter-reporter assays for three of the induced genes, each from one cluster, showed re-localization of expression to arbuscule-containing cells, supporting a role for SWEETs in the supply of sugars at biotrophic interfaces. The complex transcriptional regulation of SWEETs in roots in response to AM fungal colonization supports a model in which symplastic sucrose in cortical cells could be cleaved

  17. Arbuscular mycorrhiza Symbiosis Induces a Major Transcriptional Reprogramming of the Potato SWEET Sugar Transporter Family

    PubMed Central

    Manck-Götzenberger, Jasmin; Requena, Natalia

    2016-01-01

    Biotrophic microbes feeding on plants must obtain carbon from their hosts without killing the cells. The symbiotic Arbuscular mycorrhizal (AM) fungi colonizing plant roots do so by inducing major transcriptional changes in the host that ultimately also reprogram the whole carbon partitioning of the plant. AM fungi obtain carbohydrates from the root cortex apoplast, in particular from the periarbuscular space that surrounds arbuscules. However, the mechanisms by which cortical cells export sugars into the apoplast for fungal nutrition are unknown. Recently a novel type of sugar transporter, the SWEET, able to perform not only uptake but also efflux from cells was identified. Plant SWEETs have been shown to be involved in the feeding of pathogenic microbes and are, therefore, good candidates to play a similar role in symbiotic associations. Here we have carried out the first phylogenetic and expression analyses of the potato SWEET family and investigated its role during mycorrhiza symbiosis. The potato genome contains 35 SWEETs that cluster into the same four clades defined in Arabidopsis. Colonization of potato roots by the AM fungus Rhizophagus irregularis imposes major transcriptional rewiring of the SWEET family involving, only in roots, changes in 22 of the 35 members. None of the SWEETs showed mycorrhiza-exclusive induction and most of the 12 induced genes belong to the putative hexose transporters of clade I and II, while only two are putative sucrose transporters from clade III. In contrast, most of the repressed transcripts (10) corresponded to clade III SWEETs. Promoter-reporter assays for three of the induced genes, each from one cluster, showed re-localization of expression to arbuscule-containing cells, supporting a role for SWEETs in the supply of sugars at biotrophic interfaces. The complex transcriptional regulation of SWEETs in roots in response to AM fungal colonization supports a model in which symplastic sucrose in cortical cells could be cleaved

  18. Arbuscular mycorrhiza Symbiosis Induces a Major Transcriptional Reprogramming of the Potato SWEET Sugar Transporter Family.

    PubMed

    Manck-Götzenberger, Jasmin; Requena, Natalia

    2016-01-01

    Biotrophic microbes feeding on plants must obtain carbon from their hosts without killing the cells. The symbiotic Arbuscular mycorrhizal (AM) fungi colonizing plant roots do so by inducing major transcriptional changes in the host that ultimately also reprogram the whole carbon partitioning of the plant. AM fungi obtain carbohydrates from the root cortex apoplast, in particular from the periarbuscular space that surrounds arbuscules. However, the mechanisms by which cortical cells export sugars into the apoplast for fungal nutrition are unknown. Recently a novel type of sugar transporter, the SWEET, able to perform not only uptake but also efflux from cells was identified. Plant SWEETs have been shown to be involved in the feeding of pathogenic microbes and are, therefore, good candidates to play a similar role in symbiotic associations. Here we have carried out the first phylogenetic and expression analyses of the potato SWEET family and investigated its role during mycorrhiza symbiosis. The potato genome contains 35 SWEETs that cluster into the same four clades defined in Arabidopsis. Colonization of potato roots by the AM fungus Rhizophagus irregularis imposes major transcriptional rewiring of the SWEET family involving, only in roots, changes in 22 of the 35 members. None of the SWEETs showed mycorrhiza-exclusive induction and most of the 12 induced genes belong to the putative hexose transporters of clade I and II, while only two are putative sucrose transporters from clade III. In contrast, most of the repressed transcripts (10) corresponded to clade III SWEETs. Promoter-reporter assays for three of the induced genes, each from one cluster, showed re-localization of expression to arbuscule-containing cells, supporting a role for SWEETs in the supply of sugars at biotrophic interfaces. The complex transcriptional regulation of SWEETs in roots in response to AM fungal colonization supports a model in which symplastic sucrose in cortical cells could be cleaved

  19. The Laccaria and Tuber Genomes Reveal Unique Signatures of Mycorrhizal Symbiosis Evolution (2010 JGI User Meeting)

    SciTech Connect

    Knapp, Steve

    2010-03-24

    Francis Martin from the French agricultural research institute INRA talks on how "The Laccaria and Tuber genomes reveal unique signatures of mycorrhizal symbiosis evolution" on March 24, 2010 at the 5th Annual DOE JGI User Meeting

  20. Landau and Lifshitz' formulation of Le Chatelier's principle: an insight into symbiosis?

    PubMed

    Halabi, T

    2013-12-01

    A correspondence allows application of Landau and Lifshitz' formulation of Le Chatelier's principle from statistical physics to a simple 2-D model of biological symbiosis. The insight: symbionts stabilize the occupation of narrow peaks on fitness landscape. PMID:23851635

  1. Are heterotrophic and silica-rich eukaryotic microbes an important part of the lichen symbiosis?

    PubMed Central

    Wilkinson, David M.; Creevy, Angela L.; Kalu, Chiamaka L.; Schwartzman, David W.

    2015-01-01

    We speculate that heterotrophic and/or silica-rich eukaryotic microorganisms maybe an important part of the lichen symbiosis. None of the very few studies of heterotrophic protists associated with lichens have considered the possibility that they may be of functional significance in the lichen symbiosis. Here we start to develop, currently speculative, theoretical ideas about their potential significance. For example, all the protist taxa identified in lichens we sampled in Ohio USA depend on silica for growth and construction of their cell walls, this could suggest that silica-rich lichen symbionts may be significant in the biogeochemistry of the lichen symbiosis. We also present arguments suggesting a role for protists in nitrogen cycling within lichen thalli and a potential role in controlling bacterial populations associated with lichens. In this necessarily speculative paper we highlight areas for future research and how newer technologies may be useful for understanding the full suite of organisms involved in the lichen symbiosis. PMID:26000198

  2. Pharmaceutical Industry Off-label Promotion and Self-regulation: A Document Analysis of Off-label Promotion Rulings by the United Kingdom Prescription Medicines Code of Practice Authority 2003–2012

    PubMed Central

    Vilhelmsson, Andreas; Davis, Courtney; Mulinari, Shai

    2016-01-01

    Background European Union law prohibits companies from marketing drugs off-label. In the United Kingdom—as in some other European countries, but unlike the United States—industry self-regulatory bodies are tasked with supervising compliance with marketing rules. The objectives of this study were to (1) characterize off-label promotion rulings in the UK compared to the whistleblower-initiated cases in the US and (2) shed light on the UK self-regulatory mechanism for detecting, deterring, and sanctioning off-label promotion. Methods and Findings We conducted structured reviews of rulings by the UK self-regulatory authority, the Prescription Medicines Code of Practice Authority (PMCPA), between 2003 and 2012. There were 74 off-label promotion rulings involving 43 companies and 65 drugs. Nineteen companies were ruled in breach more than once, and ten companies were ruled in breach three or more times over the 10-y period. Drawing on a typology previously developed to analyse US whistleblower complaints, we coded and analysed the apparent strategic goals of each off-label marketing scheme and the practices consistent with those alleged goals. 50% of rulings cited efforts to expand drug use to unapproved indications, and 39% and 38% cited efforts to expand beyond approved disease entities and dosing strategies, respectively. The most frequently described promotional tactic was attempts to influence prescribers (n = 72, 97%), using print material (70/72, 97%), for example, advertisements (21/70, 30%). Although rulings cited prescribers as the prime target of off-label promotion, competing companies lodged the majority of complaints (prescriber: n = 16, 22%, versus companies: n = 42, 57%). Unlike US whistleblower complaints, few UK rulings described practices targeting consumers (n = 3, 4%), payers (n = 2, 3%), or company staff (n = 2, 3%). Eight UK rulings (11%) pertaining to six drugs described promotion of the same drug for the same off-label use as was alleged by

  3. Origin and Evolution of Nitrogen Fixation Genes on Symbiosis Islands and Plasmid in Bradyrhizobium

    PubMed Central

    Okubo, Takashi; Piromyou, Pongdet; Tittabutr, Panlada; Teaumroong, Neung; Minamisawa, Kiwamu

    2016-01-01

    The nitrogen fixation (nif) genes of nodule-forming Bradyrhizobium strains are generally located on symbiosis islands or symbiosis plasmids, suggesting that these genes have been transferred laterally. The nif genes of rhizobial and non-rhizobial Bradyrhizobium strains were compared in order to infer the evolutionary histories of nif genes. Based on all codon positions, the phylogenetic tree of concatenated nifD and nifK sequences showed that nifDK on symbiosis islands formed a different clade from nifDK on non-symbiotic loci (located outside of symbiosis islands and plasmids) with elongated branches; however, these genes were located in close proximity, when only the 1st and 2nd codon positions were analyzed. The guanine (G) and cytosine (C) content of the 3rd codon position of nifDK on symbiosis islands was lower than that on non-symbiotic loci. These results suggest that nif genes on symbiosis islands were derived from the non-symbiotic loci of Bradyrhizobium or closely related strains and have evolved toward a lower GC content with a higher substitution rate than the ancestral state. Meanwhile, nifDK on symbiosis plasmids clustered with nifDK on non-symbiotic loci in the tree representing all codon positions, and the GC content of symbiotic and non-symbiotic loci were similar. These results suggest that nif genes on symbiosis plasmids were derived from the non-symbiotic loci of Bradyrhizobium and have evolved with a similar evolutionary pattern and rate as the ancestral state. PMID:27431195

  4. Origin and Evolution of Nitrogen Fixation Genes on Symbiosis Islands and Plasmid in Bradyrhizobium.

    PubMed

    Okubo, Takashi; Piromyou, Pongdet; Tittabutr, Panlada; Teaumroong, Neung; Minamisawa, Kiwamu

    2016-09-29

    The nitrogen fixation (nif) genes of nodule-forming Bradyrhizobium strains are generally located on symbiosis islands or symbiosis plasmids, suggesting that these genes have been transferred laterally. The nif genes of rhizobial and non-rhizobial Bradyrhizobium strains were compared in order to infer the evolutionary histories of nif genes. Based on all codon positions, the phylogenetic tree of concatenated nifD and nifK sequences showed that nifDK on symbiosis islands formed a different clade from nifDK on non-symbiotic loci (located outside of symbiosis islands and plasmids) with elongated branches; however, these genes were located in close proximity, when only the 1st and 2nd codon positions were analyzed. The guanine (G) and cytosine (C) content of the 3rd codon position of nifDK on symbiosis islands was lower than that on non-symbiotic loci. These results suggest that nif genes on symbiosis islands were derived from the non-symbiotic loci of Bradyrhizobium or closely related strains and have evolved toward a lower GC content with a higher substitution rate than the ancestral state. Meanwhile, nifDK on symbiosis plasmids clustered with nifDK on non-symbiotic loci in the tree representing all codon positions, and the GC content of symbiotic and non-symbiotic loci were similar. These results suggest that nif genes on symbiosis plasmids were derived from the non-symbiotic loci of Bradyrhizobium and have evolved with a similar evolutionary pattern and rate as the ancestral state.

  5. The engine of the reef: photobiology of the coral–algal symbiosis

    PubMed Central

    Roth, Melissa S.

    2014-01-01

    Coral reef ecosystems thrive in tropical oligotrophic oceans because of the relationship between corals and endosymbiotic dinoflagellate algae called Symbiodinium. Symbiodinium convert sunlight and carbon dioxide into organic carbon and oxygen to fuel coral growth and calcification, creating habitat for these diverse and productive ecosystems. Light is thus a key regulating factor shaping the productivity, physiology, and ecology of the coral holobiont. Similar to all oxygenic photoautotrophs, Symbiodinium must safely harvest sunlight for photosynthesis and dissipate excess energy to prevent oxidative stress. Oxidative stress is caused by environmental stressors such as those associated with global climate change, and ultimately leads to breakdown of the coral–algal symbiosis known as coral bleaching. Recently, large-scale coral bleaching events have become pervasive and frequent threatening and endangering coral reefs. Because the coral–algal symbiosis is the biological engine producing the reef, the future of coral reef ecosystems depends on the ecophysiology of the symbiosis. This review examines the photobiology of the coral–algal symbiosis with particular focus on the photophysiological responses and timescales of corals and Symbiodinium. Additionally, this review summarizes the light environment and its dynamics, the vulnerability of the symbiosis to oxidative stress, the abiotic and biotic factors influencing photosynthesis, the diversity of the coral–algal symbiosis, and recent advances in the field. Studies integrating physiology with the developing “omics” fields will provide new insights into the coral–algal symbiosis. Greater physiological and ecological understanding of the coral–algal symbiosis is needed for protection and conservation of coral reefs. PMID:25202301

  6. Carbon availability triggers fungal nitrogen uptake and transport in arbuscular mycorrhizal symbiosis.

    PubMed

    Fellbaum, Carl R; Gachomo, Emma W; Beesetty, Yugandhar; Choudhari, Sulbha; Strahan, Gary D; Pfeffer, Philip E; Kiers, E Toby; Bücking, Heike

    2012-02-14

    The arbuscular mycorrhizal (AM) symbiosis, formed between the majority of land plants and ubiquitous soil fungi of the phylum Glomeromycota, is responsible for massive nutrient transfer and global carbon sequestration. AM fungi take up nutrients from the soil and exchange them against photosynthetically fixed carbon (C) from the host. Recent studies have demonstrated that reciprocal reward strategies by plant and fungal partners guarantee a "fair trade" of phosphorus against C between partners [Kiers ET, et al. (2011) Science 333:880-882], but whether a similar reward mechanism also controls nitrogen (N) flux in the AM symbiosis is not known. Using mycorrhizal root organ cultures, we manipulated the C supply to the host and fungus and followed the uptake and transport of N sources in the AM symbiosis, the enzymatic activities of arginase and urease, and fungal gene expression in the extraradical and intraradical mycelium. We found that the C supply of the host plant triggers the uptake and transport of N in the symbiosis, and that the increase in N transport is orchestrated by changes in fungal gene expression. N transport in the symbiosis is stimulated only when the C is delivered by the host across the mycorrhizal interface, not when C is supplied directly to the fungal extraradical mycelium in the form of acetate. These findings support the importance of C flux from the root to the fungus as a key trigger for N uptake and transport and provide insight into the N transport regulation in the AM symbiosis.

  7. Ethylene signalling and ethylene-targeted transcription factors are required to balance beneficial and nonbeneficial traits in the symbiosis between the endophytic fungus Piriformospora indica and Arabidopsis thaliana.

    PubMed

    Camehl, Iris; Sherameti, Irena; Venus, Yvonne; Bethke, Gerit; Varma, Ajit; Lee, Justin; Oelmüller, Ralf

    2010-03-01

    *The endophytic fungus Piriformospora indica colonizes the roots of the model plant Arabidopsis thaliana and promotes its growth and seed production. The fungus can be cultivated in axenic culture without a host, and therefore this is an excellent system to investigate plant-fungus symbiosis. *The growth of etr1, ein2 and ein3/eil1 mutant plants was not promoted or even inhibited by the fungus; the plants produced less seeds and the roots were more colonized compared with the wild-type. This correlates with a mild activation of defence responses. The overexpression of ETHYLENE RESPONSE FACTOR1 constitutively activated defence responses, strongly reduced root colonization and abolished the benefits for the plants. *Piriformospora indica-mediated stimulation of growth and seed yield was not affected by jasmonic acid, and jasmonic acid-responsive promoter beta-glucuronidase gene constructs did not respond to the fungus in Arabidopsis roots. *We propose that ethylene signalling components and ethylene-targeted transcription factors are required to balance beneficial and nonbeneficial traits in the symbiosis. The results show that the restriction of fungal growth by ethylene signalling components is required for the beneficial interaction between the two symbionts.

  8. Using technology to promote science as a basic subject for literacy: A precollege/college/industry/government collaboration

    SciTech Connect

    Redmond, B.L.; Saturnelli, A.M.

    1994-12-31

    Our goal is to ensure that All students have the opportunity to learn science, and it is being accomplished through a unique working model program that: (1) changes the way that teaching and learning take place; (2) incorporates the advanced technology of microscopy directly into the K-12 curriculum; and (3) develops R & D teacher specialists. We conducted three in-service science courses, a Summer Science Microscopy Camp, and a staff development program (the latter funded by a NYS Education Department grant) in which science professors, industrial engineers and scientists interacted with teachers and students to explore the world using high technology. This year, all 5th and 7th graders in the district (200 students) and about 1,000 high school science students are having experiences as active researchers, solving real-life, multi-step problems using all levels of microscopy, including scanning tunneling. Students develop a chronological portfolio, using multimedia formats. Our 1993 Summer Microscopy Camp attendance record was 98%, compared to the typical 75% for other programs.

  9. The characterization of six auxin-induced tomato GH3 genes uncovers a member, SlGH3.4, strongly responsive to arbuscular mycorrhizal symbiosis.

    PubMed

    Liao, Dehua; Chen, Xiao; Chen, Aiqun; Wang, Huimin; Liu, Jianjian; Liu, Junli; Gu, Mian; Sun, Shubin; Xu, Guohua

    2015-04-01

    In plants, the GH3 gene family is widely considered to be involved in a broad range of plant physiological processes, through modulation of hormonal homeostasis. Multiple GH3 genes have been functionally characterized in several plant species; however, to date, limited works to study the GH3 genes in tomato have been reported. Here, we characterize the expression and regulatory profiles of six tomato GH3 genes, SlGH3.2, SlGH3.3, SlGH3.4, SlGH3.7, SlGH3.9 and SlGH3.15, in response to different phytohormone applications and arbuscular mycorrhizal (AM) fungal colonization. All six GH3 genes showed inducible responses to external IAA, and three members were significantly up-regulated in response to AM symbiosis. In particular, SlGH3.4, the transcripts of which were barely detectable under normal growth conditions, was strongly activated in the IAA-treated and AM fungal-colonized roots. A comparison of the SlGH3.4 expression in wild-type plants and M161, a mutant with a defect in AM symbiosis, confirmed that SlGH3.4 expression is highly correlated to mycorrhizal colonization. Histochemical staining demonstrated that a 2,258 bp SlGH3.4 promoter fragment could drive β-glucuronidase (GUS) expression strongly in root tips, steles and cortical cells of IAA-treated roots, but predominantly in the fungal-colonized cells of mycorrhizal roots. A truncated 654 bp promoter failed to direct GUS expression in IAA-treated roots, but maintained the symbiosis-induced activity in mycorrhizal roots. In summary, our results suggest that a mycorrhizal signaling pathway that is at least partially independent of the auxin signaling pathway has evolved for the co-regulation of the auxin- and mycorrhiza-activated GH3 genes in plants.

  10. The characterization of six auxin-induced tomato GH3 genes uncovers a member, SlGH3.4, strongly responsive to arbuscular mycorrhizal symbiosis.

    PubMed

    Liao, Dehua; Chen, Xiao; Chen, Aiqun; Wang, Huimin; Liu, Jianjian; Liu, Junli; Gu, Mian; Sun, Shubin; Xu, Guohua

    2015-04-01

    In plants, the GH3 gene family is widely considered to be involved in a broad range of plant physiological processes, through modulation of hormonal homeostasis. Multiple GH3 genes have been functionally characterized in several plant species; however, to date, limited works to study the GH3 genes in tomato have been reported. Here, we characterize the expression and regulatory profiles of six tomato GH3 genes, SlGH3.2, SlGH3.3, SlGH3.4, SlGH3.7, SlGH3.9 and SlGH3.15, in response to different phytohormone applications and arbuscular mycorrhizal (AM) fungal colonization. All six GH3 genes showed inducible responses to external IAA, and three members were significantly up-regulated in response to AM symbiosis. In particular, SlGH3.4, the transcripts of which were barely detectable under normal growth conditions, was strongly activated in the IAA-treated and AM fungal-colonized roots. A comparison of the SlGH3.4 expression in wild-type plants and M161, a mutant with a defect in AM symbiosis, confirmed that SlGH3.4 expression is highly correlated to mycorrhizal colonization. Histochemical staining demonstrated that a 2,258 bp SlGH3.4 promoter fragment could drive β-glucuronidase (GUS) expression strongly in root tips, steles and cortical cells of IAA-treated roots, but predominantly in the fungal-colonized cells of mycorrhizal roots. A truncated 654 bp promoter failed to direct GUS expression in IAA-treated roots, but maintained the symbiosis-induced activity in mycorrhizal roots. In summary, our results suggest that a mycorrhizal signaling pathway that is at least partially independent of the auxin signaling pathway has evolved for the co-regulation of the auxin- and mycorrhiza-activated GH3 genes in plants. PMID:25535196

  11. The environmental impact of growth-promoting compounds employed by the United States beef cattle industry: history, current knowledge, and future directions.

    PubMed

    Kolok, Alan S; Sellin, Marlo K

    2008-01-01

    The current state of knowledge regarding the environmental impact of growth-promoting compounds associated with the U.S. beef cattle industry is extensive in some areas but virtually nonexistent in others. The compounds administered to the cattle are quite well understood, as are bovine metabolism and excretion. If the sex and age of the cattle on the feedlot are known, the metabolites excreted by the cattle should be predictable with a great deal of accuracy. The fate, transport, and biological effects of growth-promoting compounds are just beginning to be studied. Most of the research conducted on the fate and transport of growth-promoting compounds has focused on 17beta-E2; however, much of this research was not conducted using feedlot runoff or manure. Studies are needed that focus specifically on manures and runoff from experimental or commercial feedlots. To date, the degree to which growth-promoting compounds are released from feedlots in a bioavailable form remains a point of speculation. The environmental fate and transport of TBA, P, and MGA have not been well studied. Comparisons between the fate and transport of T and 17beta-E2, however, make it clear that compounds with similar structure may behave very differently once released into the environment. Considering that 17beta-E2 is a naturally occurring estrogen and that TBA is a nonaromatizable androgen, it is not surprising that these compounds directly impact the reproductive physiology of fishes. The effects of these two compounds have been well documented, as has been described here; however, the effects of P and MGA exposures have gone largely uninvestigated. This is a serious critical gap in our knowledge base because progestogins play an important role in sex steroid synthesis and reproduction. Clearly, additional research on the consequences of exposures to P and MGA is warranted. The majority of research investigating the effects of 17beta-E2 and TBA metabolites on fish has been conducted in

  12. Iron: an essential micronutrient for the legume-rhizobium symbiosis

    PubMed Central

    Brear, Ella M.; Day, David A.; Smith, Penelope M. C.

    2013-01-01

    Legumes, which develop a symbiosis with nitrogen-fixing bacteria, have an increased demand for iron. Iron is required for the synthesis of iron-containing proteins in the host, including the highly abundant leghemoglobin, and in bacteroids for nitrogenase and cytochromes of the electron transport chain. Deficiencies in iron can affect initiation and development of the nodule. Within root cells, iron is chelated with organic acids such as citrate and nicotianamine and distributed to other parts of the plant. Transport to the nitrogen-fixing bacteroids in infected cells of nodules is more complicated. Formation of the symbiosis results in bacteroids internalized within root cortical cells of the legume where they are surrounded by a plant-derived membrane termed the symbiosome membrane (SM). This membrane forms an interface that regulates nutrient supply to the bacteroid. Consequently, iron must cross this membrane before being supplied to the bacteroid. Iron is transported across the SM as both ferric and ferrous iron. However, uptake of Fe(II) by both the symbiosome and bacteroid is faster than Fe(III) uptake. Members of more than one protein family may be responsible for Fe(II) transport across the SM. The only Fe(II) transporter in nodules characterized to date is GmDMT1 (Glycine max divalent metal transporter 1), which is located on the SM in soybean. Like the root plasma membrane, the SM has ferric iron reductase activity. The protein responsible has not been identified but is predicted to reduce ferric iron accumulated in the symbiosome space prior to uptake by the bacteroid. With the recent publication of a number of legume genomes including Medicago truncatula and G. max, a large number of additional candidate transport proteins have been identified. Members of the NRAMP (natural resistance-associated macrophage protein), YSL (yellow stripe-like), VIT (vacuolar iron transporter), and ZIP (Zrt-, Irt-like protein) transport families show enhanced expression in

  13. Global distribution and vertical patterns of a prymnesiophyte-cyanobacteria obligate symbiosis.

    PubMed

    Cabello, Ana M; Cornejo-Castillo, Francisco M; Raho, Nicolas; Blasco, Dolors; Vidal, Montserrat; Audic, Stéphane; de Vargas, Colomban; Latasa, Mikel; Acinas, Silvia G; Massana, Ramon

    2016-03-01

    A marine symbiosis has been recently discovered between prymnesiophyte species and the unicellular diazotrophic cyanobacterium UCYN-A. At least two different UCYN-A phylotypes exist, the clade UCYN-A1 in symbiosis with an uncultured small prymnesiophyte and the clade UCYN-A2 in symbiosis with the larger Braarudosphaera bigelowii. We targeted the prymnesiophyte-UCYN-A1 symbiosis by double CARD-FISH (catalyzed reporter deposition-fluorescence in situ hybridization) and analyzed its abundance in surface samples from the MALASPINA circumnavigation expedition. Our use of a specific probe for the prymnesiophyte partner allowed us to verify that this algal species virtually always carried the UCYN-A symbiont, indicating that the association was also obligate for the host. The prymnesiophyte-UCYN-A1 symbiosis was detected in all ocean basins, displaying a patchy distribution with abundances (up to 500 cells ml(-1)) that could vary orders of magnitude. Additional vertical profiles taken at the NE Atlantic showed that this symbiosis occupied the upper water column and disappeared towards the Deep Chlorophyll Maximum, where the biomass of the prymnesiophyte assemblage peaked. Moreover, sequences of both prymnesiophyte partners were searched within a large 18S rDNA metabarcoding data set from the Tara-Oceans expedition around the world. This sequence-based analysis supported the patchy distribution of the UCYN-A1 host observed by CARD-FISH and highlighted an unexpected homogeneous distribution (at low relative abundance) of B. bigelowii in the open ocean. Our results demonstrate that partners are always in symbiosis in nature and show contrasted ecological patterns of the two related lineages.

  14. Cyclophilin and the regulation of symbiosis in Aiptasia pallida.

    PubMed

    Perez, S; Weis, V

    2008-08-01

    The sea anemone Aiptasia pallida, symbiotic with intracellular dinoflagellates, expresses a peptydyl-prolyl cis-trans isomerase (PPIase) belonging to the conserved family of cytosolic cyclophilins (ApCypA). Protein extracts from A. pallida exhibited PPIase activity. Given the high degree of conservation of ApCypA and its known function in the cellular stress response, we hypothesized that it plays a similar role in the cnidarian-dinoflagellate symbiosis. To explore its role, we inhibited the activity of cyclophilin with cyclosporin A (CsA). CsA effectively inhibited the PPIase activity of protein extracts from symbiotic A. pallida. CsA also induced the dose-dependent release of symbiotic algae from host tissues (bleaching). Laser scanning confocal microscopy using superoxide and nitric oxide-sensitive fluorescent dyes on live specimens of A. pallida revealed that CsA strongly induced the production of these known mediators of bleaching. We tested whether the CsA-sensitive isomerase activity is important for maintaining the activity of the antioxidant enzyme superoxide dismutase (SOD). SOD activity of protein extracts was not affected by pre-incubation with CsA in vitro. PMID:18723638

  15. Genetic diversity for mycorrhizal symbiosis and phosphate transporters in rice.

    PubMed

    Jeong, Kwanho; Mattes, Nicolas; Catausan, Sheryl; Chin, Joong Hyoun; Paszkowski, Uta; Heuer, Sigrid

    2015-11-01

    Phosphorus (P) is a major plant nutrient and developing crops with higher P-use efficiency is an important breeding goal. In this context we have conducted a comparative study of irrigated and rainfed rice varieties to assess genotypic differences in colonization with arbuscular mycorrhizal (AM) fungi and expression of different P transporter genes. Plants were grown in three different soil samples from a rice farm in the Philippines. The data show that AM symbiosis in all varieties was established after 4 weeks of growth under aerobic conditions and that, in soil derived from a rice paddy, natural AM populations recovered within 6 weeks. The analysis of AM marker genes (AM1, AM3, AM14) and P transporter genes for the direct Pi uptake (PT2, PT6) and AM-mediated pathway (PT11, PT13) were largely in agreement with the observed root AM colonization providing a useful tool for diversity studies. Interestingly, delayed AM colonization was observed in the aus-type rice varieties which might be due to their different root structure and might confer an advantage for weed competition in the field. The data further showed that P-starvation induced root growth and expression of the high-affinity P transporter PT6 was highest in the irrigated variety IR66 which also maintained grain yield under P-deficient field conditions. PMID:26466747

  16. Microgravity effects on the legume/Rhizobium symbiosis

    NASA Astrophysics Data System (ADS)

    Urban, James E.

    1997-01-01

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

  17. Cell and developmental biology of arbuscular mycorrhiza symbiosis.

    PubMed

    Gutjahr, Caroline; Parniske, Martin

    2013-01-01

    The default mineral nutrient acquisition strategy of land plants is the symbiosis with arbuscular mycorrhiza (AM) fungi. Research into the cell and developmental biology of AM revealed fascinating insights into the plasticity of plant cell development and of interorganismic communication. It is driven by the prospect of increased exploitation of AM benefits for sustainable agriculture. The plant cell developmental program for intracellular accommodation of AM fungi is activated by a genetically defined signaling pathway involving calcium spiking in the nucleus as second messenger. Calcium spiking is triggered by chitooligosaccharides released by AM fungi that are probably perceived via LysM domain receptor kinases. Fungal infection and calcium spiking are spatiotemporally coordinated, and only cells committed to accommodating the fungus undergo high-frequency spiking. Delivery of mineral nutrients by AM fungi occurs at tree-shaped hyphal structures, the arbuscules, in plant cortical cells. Nutrients are taken up at a plant-derived periarbuscular membrane, which surrounds fungal hyphae and carries a specific transporter composition that is of direct importance for symbiotic efficiency. An elegant study has unveiled a new and unexpected mechanism for specific protein localization to the periarbuscular membrane, which relies on the timing of gene expression to synchronize protein biosynthesis with a redirection of secretion. The control of AM development by phytohormones is currently subject to active investigation and has led to the rediscovery of strigolactones. Nearly all tested phytohormones regulate AM development, and major insights into the mechanisms of this regulation are expected in the near future.

  18. Paracatenula, an ancient symbiosis between thiotrophic Alphaproteobacteria and catenulid flatworms.

    PubMed

    Gruber-Vodicka, Harald Ronald; Dirks, Ulrich; Leisch, Nikolaus; Baranyi, Christian; Stoecker, Kilian; Bulgheresi, Silvia; Heindl, Niels Robert; Horn, Matthias; Lott, Christian; Loy, Alexander; Wagner, Michael; Ott, Jörg

    2011-07-19

    Harnessing chemosynthetic symbionts is a recurring evolutionary strategy. Eukaryotes from six phyla as well as one archaeon have acquired chemoautotrophic sulfur-oxidizing bacteria. In contrast to this broad host diversity, known bacterial partners apparently belong to two classes of bacteria--the Gamma- and Epsilonproteobacteria. Here, we characterize the intracellular endosymbionts of the mouthless catenulid flatworm genus Paracatenula as chemoautotrophic sulfur-oxidizing Alphaproteobacteria. The symbionts of Paracatenula galateia are provisionally classified as "Candidatus Riegeria galateiae" based on 16S ribosomal RNA sequencing confirmed by fluorescence in situ hybridization together with functional gene and sulfur metabolite evidence. 16S rRNA gene phylogenetic analysis shows that all 16 Paracatenula species examined harbor host species-specific intracellular Candidatus Riegeria bacteria that form a monophyletic group within the order Rhodospirillales. Comparing host and symbiont phylogenies reveals strict cocladogenesis and points to vertical transmission of the symbionts. Between 33% and 50% of the body volume of the various worm species is composed of bacterial symbionts, by far the highest proportion among all known endosymbiotic associations between bacteria and metazoans. This symbiosis, which likely originated more than 500 Mya during the early evolution of flatworms, is the oldest known animal-chemoautotrophic bacteria association. The distant phylogenetic position of the symbionts compared with other mutualistic or parasitic Alphaproteobacteria promises to illuminate the common genetic predispositions that have allowed several members of this class to successfully colonize eukaryote cells.

  19. New digestive symbiosis in the hydrothermal vent amphipoda Ventiella sulfuris.

    PubMed

    Corbari, Laure; Durand, Lucile; Cambon-Bonavita, Marie-Anne; Gaill, Françoise; Compère, Philippe

    2012-02-01

    Ventiella sulfuris Barnard and Ingram, 1990 is the most abundant amphipod species inhabiting the Eastern Pacific Rise (EPR 9°N) vent fields. This vent-endemic species is frequently encountered near colonies of Pompeii worms Alvinella pompejana. V. sulfuris specimens were collected during the oceanographic cruise LADDER II at the Bio9 (9°50.3'N, 2508m depth) hydrothermal vent site. Main objectives were to highlight the occurrence of bacterial symbiosis in V. sulfuris and to hypothesise their implications in nutrition. Observations in light and electron microscopy (SEM, TEM) showed that the outer body surface and appendages are free of microorganisms. In contrast, the digestive system revealed two major microbial communities settled in the midgut and in the hindgut. Gut contents showed bacterial traces together with abundant fragments of Alvinellid cuticle and setae, from A. pompejana, suggesting that V. sulfuris could directly feed on Alvinellids and/or on their bacterial epibionts. Molecular analyses based on the 16S rRNA genes revealed the diversity of bacterial communities in the digestive system, of which, the Epsilonproteobacteria phylum, could be considered as one of the major bacterial group. Hypotheses were proposed on their symbiotic features and their implications in V. sulfuris nutrition.

  20. Paracatenula, an ancient symbiosis between thiotrophic Alphaproteobacteria and catenulid flatworms

    PubMed Central

    Gruber-Vodicka, Harald Ronald; Dirks, Ulrich; Leisch, Nikolaus; Stoecker, Kilian; Bulgheresi, Silvia; Heindl, Niels Robert; Horn, Matthias; Lott, Christian; Loy, Alexander; Wagner, Michael; Ott, Jörg

    2011-01-01

    Harnessing chemosynthetic symbionts is a recurring evolutionary strategy. Eukaryotes from six phyla as well as one archaeon have acquired chemoautotrophic sulfur-oxidizing bacteria. In contrast to this broad host diversity, known bacterial partners apparently belong to two classes of bacteria—the Gamma- and Epsilonproteobacteria. Here, we characterize the intracellular endosymbionts of the mouthless catenulid flatworm genus Paracatenula as chemoautotrophic sulfur-oxidizing Alphaproteobacteria. The symbionts of Paracatenula galateia are provisionally classified as “Candidatus Riegeria galateiae” based on 16S ribosomal RNA sequencing confirmed by fluorescence in situ hybridization together with functional gene and sulfur metabolite evidence. 16S rRNA gene phylogenetic analysis shows that all 16 Paracatenula species examined harbor host species-specific intracellular Candidatus Riegeria bacteria that form a monophyletic group within the order Rhodospirillales. Comparing host and symbiont phylogenies reveals strict cocladogenesis and points to vertical transmission of the symbionts. Between 33% and 50% of the body volume of the various worm species is composed of bacterial symbionts, by far the highest proportion among all known endosymbiotic associations between bacteria and metazoans. This symbiosis, which likely originated more than 500 Mya during the early evolution of flatworms, is the oldest known animal–chemoautotrophic bacteria association. The distant phylogenetic position of the symbionts compared with other mutualistic or parasitic Alphaproteobacteria promises to illuminate the common genetic predispositions that have allowed several members of this class to successfully colonize eukaryote cells. PMID:21709249

  1. Algal ancestor of land plants was preadapted for symbiosis.

    PubMed

    Delaux, Pierre-Marc; Radhakrishnan, Guru V; Jayaraman, Dhileepkumar; Cheema, Jitender; Malbreil, Mathilde; Volkening, Jeremy D; Sekimoto, Hiroyuki; Nishiyama, Tomoaki; Melkonian, Michael; Pokorny, Lisa; Rothfels, Carl J; Sederoff, Heike Winter; Stevenson, Dennis W; Surek, Barbara; Zhang, Yong; Sussman, Michael R; Dunand, Christophe; Morris, Richard J; Roux, Christophe; Wong, Gane Ka-Shu; Oldroyd, Giles E D; Ané, Jean-Michel

    2015-10-27

    Colonization of land by plants was a major transition on Earth, but the developmental and genetic innovations required for this transition remain unknown. Physiological studies and the fossil record strongly suggest that the ability of the first land plants to form symbiotic associations with beneficial fungi was one of these critical innovations. In angiosperms, genes required for the perception and transduction of diffusible fungal signals for root colonization and for nutrient exchange have been characterized. However, the origin of these genes and their potential correlation with land colonization remain elusive. A comprehensive phylogenetic analysis of 259 transcriptomes and 10 green algal and basal land plant genomes, coupled with the characterization of the evolutionary path leading to the appearance of a key regulator, a calcium- and calmodulin-dependent protein kinase, showed that the symbiotic signaling pathway predated the first land plants. In contrast, downstream genes required for root colonization and their specific expression pattern probably appeared subsequent to the colonization of land. We conclude that the most recent common ancestor of extant land plants and green algae was preadapted for symbiotic associations. Subsequent improvement of this precursor stage in early land plants through rounds of gene duplication led to the acquisition of additional pathways and the ability to form a fully functional arbuscular mycorrhizal symbiosis. PMID:26438870

  2. The effects of SO sub 2 on Azolla - Anabaena symbiosis

    SciTech Connect

    Jaeseoun Hur; Wellburn, A.R. )

    1991-05-01

    Cultures of Azolla pinnata containing Anabaena were investigated as a sensitive and reproducible bioindicator of air pollution. Three equal doses of SO{sub 2} (week*ppb: 1*100, 2*50, 4*25) were applied to Azolla cultures growing in nitrogen-free medium in a specially-designed exposure system. Exposure to high concentrations of SO{sub 2} showed highly significant reductions in growth of the fern, while nitrogen fixation and heterocyst development were severely damaged. This was associated with a reduction of protein content in the SO{sub 2}-exposed ferns and again more significant at higher SO{sub 2} levels. There was a variation in the absolute amount of the individual pigments between SO{sub 2} doses and/or treatments which was related to the physiological development of the ferns throughout the fumigations. Moreover, the ratio of violaxanthin to antheraxanthin in the 100 ppb SO{sub 2}-treated ferns was significantly higher than that in the clean air-grown ferns. The results clearly demonstrate that SO{sub 2} has adverse effects on the symbiosis and suggest that this fern is a promising bioindicator of air pollution and a very good model to investigate the inter-relationships between photosynthesis, nitrogen fixation and air pollution stress.

  3. Crystal structure of a symbiosis-related lectin from octocoral.

    PubMed

    Kita, Akiko; Jimbo, Mitsuru; Sakai, Ryuichi; Morimoto, Yukio; Miki, Kunio

    2015-09-01

    D-Galactose-binding lectin from the octocoral, Sinularia lochmodes (SLL-2), distributes densely on the cell surface of microalgae, Symbiodinium sp., an endosymbiotic dinoflagellate of the coral, and is also shown to be a chemical cue that transforms dinoflagellate into a non-motile (coccoid) symbiotic state. SLL-2 binds with high affinity to the Forssman antigen (N-acetylgalactosamine(GalNAc)α1-3GalNAcβ1-3Galα1-4Galβ1-4Glc-ceramide), and the presence of Forssman antigen-like sugar on the surface of Symbiodinium CS-156 cells was previously confirmed. Here we report the crystal structures of SLL-2 and its GalNAc complex as the first crystal structures of a lectin involved in the symbiosis between coral and dinoflagellate. N-Linked sugar chains and a galactose derivative binding site common to H-type lectins were observed in each monomer of the hexameric SLL-2 crystal structure. In addition, unique sugar-binding site-like regions were identified at the top and bottom of the hexameric SLL-2 structure. These structural features suggest a possible binding mode between SLL-2 and Forssman antigen-like pentasaccharide. PMID:26022515

  4. Microbial fuel cells for robotics: energy autonomy through artificial symbiosis.

    PubMed

    Ieropoulos, Ioannis A; Greenman, John; Melhuish, Chris; Horsfield, Ian

    2012-06-01

    The development of the microbial fuel cell (MFC) technology has seen an enormous growth over the last hundred years since its inception by Potter in 1911. The technology has reached a level of maturity that it is now considered to be a field in its own right with a growing scientific community. The highest level of activity has been recorded over the last decade and it is perhaps considered commonplace that MFCs are primarily suitable for stationary, passive wastewater treatment applications. Sceptics have certainly not considered MFCs as serious contenders in the race for developing renewable energy technologies. Yet this is the only type of alternative system that can convert organic waste-widely distributed around the globe-directly into electricity, and therefore, the only technology that will allow artificial agents to autonomously operate in a plethora of environments. This Minireview describes the history and current state-of-the-art regarding MFCs in robotics and their vital role in artificial symbiosis and autonomy. Furthermore, the article demonstrates how pursuing practical robotic applications can provide insights of the core MFC technology in general.

  5. Synthetic biology approaches to engineering the nitrogen symbiosis in cereals.

    PubMed

    Rogers, Christian; Oldroyd, Giles E D

    2014-05-01

    Nitrogen is abundant in the earth's atmosphere but, unlike carbon, cannot be directly assimilated by plants. The limitation this places on plant productivity has been circumvented in contemporary agriculture through the production and application of chemical fertilizers. The chemical reduction of nitrogen for this purpose consumes large amounts of energy and the reactive nitrogen released into the environment as a result of fertilizer application leads to greenhouse gas emissions, as well as widespread eutrophication of aquatic ecosystems. The environmental impacts are intensified by injudicious use of fertilizers in many parts of the world. Simultaneously, limitations in the production and supply of chemical fertilizers in other regions are leading to low agricultural productivity and malnutrition. Nitrogen can be directly fixed from the atmosphere by some bacteria and Archaea, which possess the enzyme nitrogenase. Some plant species, most notably legumes, have evolved close symbiotic associations with nitrogen-fixing bacteria. Engineering cereal crops with the capability to fix their own nitrogen could one day address the problems created by the over- and under-use of nitrogen fertilizers in agriculture. This could be achieved either by expression of a functional nitrogenase enzyme in the cells of the cereal crop or through transferring the capability to form a symbiotic association with nitrogen-fixing bacteria. While potentially transformative, these biotechnological approaches are challenging; however, with recent advances in synthetic biology they are viable long-term goals. This review discusses the possibility of these biotechnological solutions to the nitrogen problem, focusing on engineering the nitrogen symbiosis in cereals.

  6. Crystal structure of a symbiosis-related lectin from octocoral.

    PubMed

    Kita, Akiko; Jimbo, Mitsuru; Sakai, Ryuichi; Morimoto, Yukio; Miki, Kunio

    2015-09-01

    D-Galactose-binding lectin from the octocoral, Sinularia lochmodes (SLL-2), distributes densely on the cell surface of microalgae, Symbiodinium sp., an endosymbiotic dinoflagellate of the coral, and is also shown to be a chemical cue that transforms dinoflagellate into a non-motile (coccoid) symbiotic state. SLL-2 binds with high affinity to the Forssman antigen (N-acetylgalactosamine(GalNAc)α1-3GalNAcβ1-3Galα1-4Galβ1-4Glc-ceramide), and the presence of Forssman antigen-like sugar on the surface of Symbiodinium CS-156 cells was previously confirmed. Here we report the crystal structures of SLL-2 and its GalNAc complex as the first crystal structures of a lectin involved in the symbiosis between coral and dinoflagellate. N-Linked sugar chains and a galactose derivative binding site common to H-type lectins were observed in each monomer of the hexameric SLL-2 crystal structure. In addition, unique sugar-binding site-like regions were identified at the top and bottom of the hexameric SLL-2 structure. These structural features suggest a possible binding mode between SLL-2 and Forssman antigen-like pentasaccharide.

  7. Algal ancestor of land plants was preadapted for symbiosis

    PubMed Central

    Delaux, Pierre-Marc; Radhakrishnan, Guru V.; Jayaraman, Dhileepkumar; Cheema, Jitender; Malbreil, Mathilde; Volkening, Jeremy D.; Sekimoto, Hiroyuki; Nishiyama, Tomoaki; Melkonian, Michael; Pokorny, Lisa; Rothfels, Carl J.; Sederoff, Heike Winter; Stevenson, Dennis W.; Surek, Barbara; Zhang, Yong; Sussman, Michael R.; Dunand, Christophe; Morris, Richard J.; Roux, Christophe; Wong, Gane Ka-Shu; Oldroyd, Giles E. D.; Ané, Jean-Michel

    2015-01-01

    Colonization of land by plants was a major transition on Earth, but the developmental and genetic innovations required for this transition remain unknown. Physiological studies and the fossil record strongly suggest that the ability of the first land plants to form symbiotic associations with beneficial fungi was one of these critical innovations. In angiosperms, genes required for the perception and transduction of diffusible fungal signals for root colonization and for nutrient exchange have been characterized. However, the origin of these genes and their potential correlation with land colonization remain elusive. A comprehensive phylogenetic analysis of 259 transcriptomes and 10 green algal and basal land plant genomes, coupled with the characterization of the evolutionary path leading to the appearance of a key regulator, a calcium- and calmodulin-dependent protein kinase, showed that the symbiotic signaling pathway predated the first land plants. In contrast, downstream genes required for root colonization and their specific expression pattern probably appeared subsequent to the colonization of land. We conclude that the most recent common ancestor of extant land plants and green algae was preadapted for symbiotic associations. Subsequent improvement of this precursor stage in early land plants through rounds of gene duplication led to the acquisition of additional pathways and the ability to form a fully functional arbuscular mycorrhizal symbiosis. PMID:26438870

  8. Algal ancestor of land plants was preadapted for symbiosis.

    PubMed

    Delaux, Pierre-Marc; Radhakrishnan, Guru V; Jayaraman, Dhileepkumar; Cheema, Jitender; Malbreil, Mathilde; Volkening, Jeremy D; Sekimoto, Hiroyuki; Nishiyama, Tomoaki; Melkonian, Michael; Pokorny, Lisa; Rothfels, Carl J; Sederoff, Heike Winter; Stevenson, Dennis W; Surek, Barbara; Zhang, Yong; Sussman, Michael R; Dunand, Christophe; Morris, Richard J; Roux, Christophe; Wong, Gane Ka-Shu; Oldroyd, Giles E D; Ané, Jean-Michel

    2015-10-27

    Colonization of land by plants was a major transition on Earth, but the developmental and genetic innovations required for this transition remain unknown. Physiological studies and the fossil record strongly suggest that the ability of the first land plants to form symbiotic associations with beneficial fungi was one of these critical innovations. In angiosperms, genes required for the perception and transduction of diffusible fungal signals for root colonization and for nutrient exchange have been characterized. However, the origin of these genes and their potential correlation with land colonization remain elusive. A comprehensive phylogenetic analysis of 259 transcriptomes and 10 green algal and basal land plant genomes, coupled with the characterization of the evolutionary path leading to the appearance of a key regulator, a calcium- and calmodulin-dependent protein kinase, showed that the symbiotic signaling pathway predated the first land plants. In contrast, downstream genes required for root colonization and their specific expression pattern probably appeared subsequent to the colonization of land. We conclude that the most recent common ancestor of extant land plants and green algae was preadapted for symbiotic associations. Subsequent improvement of this precursor stage in early land plants through rounds of gene duplication led to the acquisition of additional pathways and the ability to form a fully functional arbuscular mycorrhizal symbiosis.

  9. CbrA is a stationary-phase regulator of cell surface physiology and legume symbiosis in Sinorhizobium meliloti.

    PubMed

    Gibson, Katherine E; Campbell, Gordon R; Lloret, Javier; Walker, Graham C

    2006-06-01

    Sinorhizobium meliloti produces an exopolysaccharide called succinoglycan that plays a critical role in promoting symbiosis with its host legume, alfalfa (Medicago sativa). We performed a transposon mutagenesis and screened for mutants with altered succinoglycan production and a defect in symbiosis. In this way, we identified a putative two-component histidine kinase associated with a PAS sensory domain, now designated CbrA (calcofluor-bright regulator A). The cbrA::Tn5 mutation causes overproduction of succinoglycan and results in increased accumulation of low-molecular-weight forms of this exopolysaccharide. Our results suggest the cbrA::Tn5 allele leads to this succinoglycan phenotype through increased expression of exo genes required for succinoglycan biosynthesis and modification. Interestingly, CbrA-dependent regulation of exo and exs genes is observed almost exclusively during stationary-phase growth. The cbrA::Tn5 mutant also has an apparent cell envelope defect, based on increased sensitivity to a number of toxic compounds, including the bile salt deoxycholate and the hydrophobic dye crystal violet. Growth of the cbrA mutant is also slowed under oxidative-stress conditions. The CbrA-regulated genes exsA and exsE encode putative inner membrane ABC transporters with a high degree of similarity to lipid exporters. ExsA is homologous to the Escherichia coli MsbA protein, which is required for lipopolysaccharide transport, while ExsE is a member of the eukaryotic family of ABCD/hALD peroxisomal membrane proteins involved in transport of very long-chain fatty acids, which are a unique component of the lipopolysaccharides of alphaproteobacteria. Thus, CbrA could play a role in regulating the lipopolysaccharide or lipoprotein components of the cell envelope. PMID:16740957

  10. DELLA proteins regulate expression of a subset of AM symbiosis-induced genes in Medicago truncatula

    PubMed Central

    Floss, Daniela S.; Lévesque-Tremblay, Véronique; Park, Hee-Jin; Harrison, Maria J.

    2016-01-01

    ABSTRACT The majority of the vascular flowering plants form symbiotic associations with fungi from the phylum Glomeromycota through which both partners gain access to nutrients, either mineral nutrients in the case of the plant, or carbon, in the case of the fungus.1 The association develops in the roots and requires substantial remodeling of the root cortical cells where branched fungal hyphae, called arbuscules, are housed in a new membrane-bound apoplastic compartment.2 Nutrient exchange between the symbionts occurs over this interface and its development and maintenance is critical for symbiosis. Previously, we showed that DELLA proteins, which are well known as repressors of gibberellic acid signaling, also regulate development of AM symbiosis and are necessary to enable arbuscule development.3 Furthermore, constitutive overexpression of a dominant DELLA protein (della1-Δ18) is sufficient to induce transcripts of several AM symbiosis-induced genes, even in the absence of the fungal symbiont.4 Here we further extend this approach and identify AM symbiosis genes that respond transcriptionally to constitutive expression of a dominant DELLA protein and also genes that do respond to this treatment. Additionally, we demonstrate that DELLAs interact with REQUIRED FOR ARBUSCULE DEVELOPMENT 1 (RAD1) which further extends our knowledge of GRAS factor complexes that have the potential to regulate gene expression during AM symbiosis. PMID:26984507

  11. DELLA proteins regulate expression of a subset of AM symbiosis-induced genes in Medicago truncatula.

    PubMed

    Floss, Daniela S; Lévesque-Tremblay, Véronique; Park, Hee-Jin; Harrison, Maria J

    2016-01-01

    The majority of the vascular flowering plants form symbiotic associations with fungi from the phylum Glomeromycota through which both partners gain access to nutrients, either mineral nutrients in the case of the plant, or carbon, in the case of the fungus. (1) The association develops in the roots and requires substantial remodeling of the root cortical cells where branched fungal hyphae, called arbuscules, are housed in a new membrane-bound apoplastic compartment. (2) Nutrient exchange between the symbionts occurs over this interface and its development and maintenance is critical for symbiosis. Previously, we showed that DELLA proteins, which are well known as repressors of gibberellic acid signaling, also regulate development of AM symbiosis and are necessary to enable arbuscule development. (3) Furthermore, constitutive overexpression of a dominant DELLA protein (della1-Δ18) is sufficient to induce transcripts of several AM symbiosis-induced genes, even in the absence of the fungal symbiont. (4) Here we further extend this approach and identify AM symbiosis genes that respond transcriptionally to constitutive expression of a dominant DELLA protein and also genes that do respond to this treatment. Additionally, we demonstrate that DELLAs interact with REQUIRED FOR ARBUSCULE DEVELOPMENT 1 (RAD1) which further extends our knowledge of GRAS factor complexes that have the potential to regulate gene expression during AM symbiosis.

  12. Laser microdissection and its application to analyze gene expression in arbuscular mycorrhizal symbiosis.

    PubMed

    Gomez, S Karen; Harrison, Maria J

    2009-05-01

    Phosphorus is essential for plant growth, and in many soils phosphorus availability limits crop production. Most plants in natural ecosystems obtain phosphorus via a symbiotic partnership with arbuscular mycorrhizal (AM) fungi. While the significance of these associations is apparent, their molecular basis is poorly understood. Consequently, the potential to harness the mycorrhizal symbiosis to improve phosphorus nutrition in agriculture is not realized. Transcript profiling has recently been used to investigate gene expression changes that accompany development of the AM symbiosis. While these approaches have enabled the identification of AM-symbiosis-associated genes, they have generally involved the use of RNA from whole mycorrhizal roots. Laser microdissection techniques allow the dissection and capture of individual cells from a tissue. RNA can then be isolated from these samples and cell-type specific gene expression information can be obtained. This technology has been applied to obtain cells from plants and more recently to study plant-microbe interactions. The latter techniques, particularly those developed for root-microbe interactions, are of relevance to plant-parasitic weed research. Here, laser microdissection, its use in plant biology and in particular plant-microbe interactions are discussed. An overview of the AM symbiosis is then provided, with a focus on recent advances in understanding development of the arbuscule-cortical cell interface. Finally, the recent applications of laser microdissection for analyses of AM symbiosis are discussed.

  13. Lipo-chitin oligosaccharides, plant symbiosis signalling molecules that modulate mammalian angiogenesis in vitro.

    PubMed

    Djordjevic, Michael A; Bezos, Anna; Susanti; Marmuse, Laurence; Driguez, Hugues; Samain, Eric; Vauzeilles, Boris; Beau, Jean-Marie; Kordbacheh, Farzaneh; Rolfe, Barry G; Schwörer, Ralf; Daines, Alison M; Gresshoff, Peter M; Parish, Christopher R

    2014-01-01

    Lipochitin oligosaccharides (LCOs) are signaling molecules required by ecologically and agronomically important bacteria and fungi to establish symbioses with diverse land plants. In plants, oligo-chitins and LCOs can differentially interact with different lysin motif (LysM) receptors and affect innate immunity responses or symbiosis-related pathways. In animals, oligo-chitins also induce innate immunity and other physiological responses but LCO recognition has not been demonstrated. Here LCO and LCO-like compounds are shown to be biologically active in mammals in a structure dependent way through the modulation of angiogenesis, a tightly-regulated process involving the induction and growth of new blood vessels from existing vessels. The testing of 24 LCO, LCO-like or oligo-chitin compounds resulted in structure-dependent effects on angiogenesis in vitro leading to promotion, or inhibition or nil effects. Like plants, the mammalian LCO biological activity depended upon the presence and type of terminal substitutions. Un-substituted oligo-chitins of similar chain lengths were unable to modulate angiogenesis indicating that mammalian cells, like plant cells, can distinguish between LCOs and un-substituted oligo-chitins. The cellular mode-of-action of the biologically active LCOs in mammals was determined. The stimulation or inhibition of endothelial cell adhesion to vitronectin or fibronectin correlated with their pro- or anti-angiogenic activity. Importantly, novel and more easily synthesised LCO-like disaccharide molecules were also biologically active and de-acetylated chitobiose was shown to be the primary structural basis of recognition. Given this, simpler chitin disaccharides derivatives based on the structure of biologically active LCOs were synthesised and purified and these showed biological activity in mammalian cells. Since important chronic disease states are linked to either insufficient or excessive angiogenesis, LCO and LCO-like molecules may have the

  14. Functional analysis of the novel mycorrhiza-specific phosphate transporter AsPT1 and PHT1 family from Astragalus sinicus during the arbuscular mycorrhizal symbiosis.

    PubMed

    Xie, Xianan; Huang, Wu; Liu, Fengchuan; Tang, Nianwu; Liu, Yi; Lin, Hui; Zhao, Bin

    2013-05-01

    Arbuscular mycorrhizas contribute significantly to inorganic phosphate (Pi) uptake in plants. Gene networks involved in the regulation and function of the Pht1 family transporters in legume species during AM symbiosis are not fully understood. In order to characterize the six distinct members of Pht1 transporters in mycorrhizal Astragalus sinicus, we combined cellular localization, heterologous functional expression in yeast with expression/subcellular localization studies and reverse genetics approaches in planta. Pht1;1 and Pht1;4 silenced lines were generated to uncover the role of the newly discovered dependence of the AM symbiosis on another phosphate transporter AsPT1 besides AsPT4. These Pht1 transporters are triggered in Pi-starved mycorrhizal roots. AsPT1 and AsPT4 were localized in arbuscule-containing cells of the cortex. The analysis of promoter sequences revealed conserved motifs in both AsPT1 and AsPT4. AsPT1 overexpression showed higher mycorrhization levels than controls for parameters analysed, including abundance of arbuscules. By contrast, knockdown of AsPT1 by RNA interference led to degenerating or dead arbuscule phenotypes identical to that of AsPT4 silencing lines. AsPT4 but not AsPT1 is required for symbiotic Pi uptake. These results suggest that both, AsPT1 and AsPT4, are required for the AM symbiosis, most importantly, AsPT1 may serve as a novel symbiotic transporter for AM development.

  15. Structural basis for regulation of rhizobial nodulation and symbiosis gene expression by the regulatory NolR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The symbiosis between rhizobial microbes and host plants involves the coordinated expression of multiple genes, which leads to nodule formation and nitrogen fixation. As part of the transcriptional machinery for nodulation and symbiosis across a range of Rhizobium, NolR serves as a global regulatory...

  16. Shared Skeletal Support in a Coral-Hydroid Symbiosis

    PubMed Central

    Pantos, Olga; Hoegh-Guldberg, Ove

    2011-01-01

    Hydroids form symbiotic relationships with a range of invertebrate hosts. Where they live with colonial invertebrates such as corals or bryozoans the hydroids may benefit from the physical support and protection of their host's hard exoskeleton, but how they interact with them is unknown. Electron microscopy was used to investigate the physical interactions between the colonial hydroid Zanclea margaritae and its reef-building coral host Acropora muricata. The hydroid tissues extend below the coral tissue surface sitting in direct contact with the host's skeleton. Although this arrangement provides the hydroid with protective support, it also presents problems of potential interference with the coral's growth processes and exposes the hydroid to overgrowth and smothering. Desmocytes located within the epidermal layer of the hydroid's perisarc-free hydrorhizae fasten it to the coral skeleton. The large apical surface area of the desmocyte and high bifurcation of the distal end within the mesoglea, as well as the clustering of desmocytes suggests that a very strong attachment between the hydroid and the coral skeleton. This is the first study to provide a detailed description of how symbiotic hydroids attach to their host's skeleton, utilising it for physical support. Results suggest that the loss of perisarc, a characteristic commonly associated with symbiosis, allows the hydroid to utilise desmocytes for attachment. The use of these anchoring structures provides a dynamic method of attachment, facilitating detachment from the coral skeleton during extension, thereby avoiding overgrowth and smothering enabling the hydroid to remain within the host colony for prolonged periods of time. PMID:21695083

  17. Stress tolerance in plants via habitat-adapted symbiosis

    USGS Publications Warehouse

    Rodriguez, R.J.; Henson, J.; Van Volkenburgh, E.; Hoy, M.; Wright, L.; Beckwith, F.; Kim, Y.-O.; Redman, R.S.

    2008-01-01

    We demonstrate that native grass species from coastal and geothermal habitats require symbiotic fungal endophytes for salt and heat tolerance, respectively. Symbiotically conferred stress tolerance is a habitat-specific phenomenon with geothermal endophytes conferring heat but not salt tolerance, and coastal endophytes conferring salt but not heat tolerance. The same fungal species isolated from plants in habitats devoid of salt or heat stress did not confer these stress tolerances. Moreover, fungal endophytes from agricultural crops conferred disease resistance and not salt or heat tolerance. We define habitat-specific, symbiotically-conferred stress tolerance as habitat-adapted symbiosis and hypothesize that it is responsible for the establishment of plants in high-stress habitats. The agricultural, coastal and geothermal plant endophytes also colonized tomato (a model eudicot) and conferred disease, salt and heat tolerance, respectively. In addition, the coastal plant endophyte colonized rice (a model monocot) and conferred salt tolerance. These endophytes have a broad host range encompassing both monocots and eudicots. Interestingly, the endophytes also conferred drought tolerance to plants regardless of the habitat of origin. Abiotic stress tolerance correlated either with a decrease in water consumption or reactive oxygen sensitivity/generation but not to increased osmolyte production. The ability of fungal endophytes to confer stress tolerance to plants may provide a novel strategy for mitigating the impacts of global climate change on agricultural and native plant communities.The ISME Journal (2008) 2, 404-416; doi:10.1038/ismej.2007.106; published online 7 February 2008. ?? 2008 International Society for Microbial Ecology All rights reserved.

  18. Impact of simulated microgravity on the normal developmental time line of an animal-bacteria symbiosis

    PubMed Central

    Foster, Jamie S.; Khodadad, Christina L. M.; Ahrendt, Steven R.; Parrish, Mirina L.

    2013-01-01

    The microgravity environment during space flight imposes numerous adverse effects on animal and microbial physiology. It is unclear, however, how microgravity impacts those cellular interactions between mutualistic microbes and their hosts. Here, we used the symbiosis between the host squid Euprymna scolopes and its luminescent bacterium Vibrio fischeri as a model system. We examined the impact of simulated microgravity on the timeline of bacteria-induced development in the host light organ, the site of the symbiosis. To simulate the microgravity environment, host squid and symbiosis-competent bacteria were incubated together in high-aspect ratio rotating wall vessel bioreactors and examined throughout the early stages of the bacteria-induced morphogenesis. The host innate immune response was suppressed under simulated microgravity; however, there was an acceleration of bacteria-induced apoptosis and regression in the host tissues. These results suggest that the space flight environment may alter the cellular interactions between animal hosts and their natural healthy microbiome. PMID:23439280

  19. Neo-Symbiosis: The Next Stage in the Evolution of Human Information Interaction.

    SciTech Connect

    Griffith, Douglas; Greitzer, Frank L.

    2008-12-01

    In his 1960 paper Man-Machine Symbiosis, Licklider predicted that human brains and computing machines will be coupled in a tight partnership that will think as no human brain has ever thought and process data in a way not approached by the information-handling machines we know today. Today we are on the threshold of resurrecting the vision of symbiosis. While Licklider’s original vision suggested a co-equal relationship, here we discuss an updated vision, neo-symbiosis, in which the human holds a superordinate position in an intelligent human-computer collaborative environment. This paper was originally published as a journal article and is being published as a chapter in an upcoming book series, Advances in Novel Approaches in Cognitive Informatics and Natural Intelligence.

  20. Resistance to Antiangiogenic Therapies by Metabolic Symbiosis in Renal Cell Carcinoma PDX Models and Patients.

    PubMed

    Jiménez-Valerio, Gabriela; Martínez-Lozano, Mar; Bassani, Nicklas; Vidal, August; Ochoa-de-Olza, María; Suárez, Cristina; García-Del-Muro, Xavier; Carles, Joan; Viñals, Francesc; Graupera, Mariona; Indraccolo, Stefano; Casanovas, Oriol

    2016-05-10

    Antiangiogenic drugs are used clinically for treatment of renal cell carcinoma (RCC) as a standard first-line treatment. Nevertheless, these agents primarily serve to stabilize disease, and resistance eventually develops concomitant with progression. Here, we implicate metabolic symbiosis between tumor cells distal and proximal to remaining vessels as a mechanism of resistance to antiangiogenic therapies in patient-derived RCC orthoxenograft (PDX) models and in clinical samples. This metabolic patterning is regulated by the mTOR pathway, and its inhibition effectively blocks metabolic symbiosis in PDX models. Clinically, patients treated with antiangiogenics consistently present with histologic signatures of metabolic symbiosis that are exacerbated in resistant tumors. Furthermore, the mTOR pathway is also associated in clinical samples, and its inhibition eliminates symbiotic patterning in patient samples. Overall, these data support a mechanism of resistance to antiangiogenics involving metabolic compartmentalization of tumor cells that can be inhibited by mTOR-targeted drugs.

  1. Impact of simulated microgravity on the normal developmental time line of an animal-bacteria symbiosis.

    PubMed

    Foster, Jamie S; Khodadad, Christina L M; Ahrendt, Steven R; Parrish, Mirina L

    2013-01-01

    The microgravity environment during space flight imposes numerous adverse effects on animal and microbial physiology. It is unclear, however, how microgravity impacts those cellular interactions between mutualistic microbes and their hosts. Here, we used the symbiosis between the host squid Euprymna scolopes and its luminescent bacterium Vibrio fischeri as a model system. We examined the impact of simulated microgravity on the timeline of bacteria-induced development in the host light organ, the site of the symbiosis. To simulate the microgravity environment, host squid and symbiosis-competent bacteria were incubated together in high-aspect ratio rotating wall vessel bioreactors and examined throughout the early stages of the bacteria-induced morphogenesis. The host innate immune response was suppressed under simulated microgravity; however, there was an acceleration of bacteria-induced apoptosis and regression in the host tissues. These results suggest that the space flight environment may alter the cellular interactions between animal hosts and their natural healthy microbiome. PMID:23439280

  2. A widespread plant-fungal-bacterial symbiosis promotes plant biodiversity, plant nutrition and seedling recruitment.

    PubMed

    van der Heijden, Marcel G A; de Bruin, Susanne; Luckerhoff, Ludo; van Logtestijn, Richard S P; Schlaeppi, Klaus

    2016-02-01

    Highly diverse microbial assemblages colonize plant roots. It is still poorly understood whether different members of this root microbiome act synergistically by supplying different services (for example, different limiting nutrients) to plants and plant communities. In order to test this, we manipulated the presence of two widespread plant root symbionts, arbuscular mycorrhizal fungi and nitrogen-fixing rhizobia bacteria in model grassland communities established in axenic microcosms. Here, we demonstrate that both symbionts complement each other resulting in increased plant diversity, enhanced seedling recruitment and improved nutrient acquisition compared with a single symbiont situation. Legume seedlings obtained up to 15-fold higher productivity if they formed an association with both symbionts, opposed to productivity they reached with only one symbiont. Our results reveal the importance of functional diversity of symbionts and demonstrate that different members of the root microbiome can complement each other in acquiring different limiting nutrients and in driving important ecosystem functions.

  3. Heritable symbiosis: The advantages and perils of an evolutionary rabbit hole

    PubMed Central

    Bennett, Gordon M.; Moran, Nancy A.

    2015-01-01

    Many eukaryotes have obligate associations with microorganisms that are transmitted directly between generations. A model for heritable symbiosis is the association of aphids, a clade of sap-feeding insects, and Buchnera aphidicola, a gammaproteobacterium that colonized an aphid ancestor 150 million years ago and persists in almost all 5,000 aphid species. Symbiont acquisition enables evolutionary and ecological expansion; aphids are one of many insect groups that would not exist without heritable symbiosis. Receiving less attention are potential negative ramifications of symbiotic alliances. In the short run, symbionts impose metabolic costs. Over evolutionary time, hosts evolve dependence beyond the original benefits of the symbiosis. Symbiotic partners enter into an evolutionary spiral that leads to irreversible codependence and associated risks. Host adaptations to symbiosis (e.g., immune-system modification) may impose vulnerabilities. Symbiont genomes also continuously accumulate deleterious mutations, limiting their beneficial contributions and environmental tolerance. Finally, the fitness interests of obligate heritable symbionts are distinct from those of their hosts, leading to selfish tendencies. Thus, genes underlying the host–symbiont interface are predicted to follow a coevolutionary arms race, as observed for genes governing host–pathogen interactions. On the macroevolutionary scale, the rapid evolution of interacting symbiont and host genes is predicted to accelerate host speciation rates by generating genetic incompatibilities. However, degeneration of symbiont genomes may ultimately limit the ecological range of host species, potentially increasing extinction risk. Recent results for the aphid–Buchnera symbiosis and related systems illustrate that, whereas heritable symbiosis can expand ecological range and spur diversification, it also presents potential perils. PMID:25713367

  4. CERBERUS and NSP1 of Lotus japonicus are common symbiosis genes that modulate arbuscular mycorrhiza development.

    PubMed

    Takeda, Naoya; Tsuzuki, Syusaku; Suzaki, Takuya; Parniske, Martin; Kawaguchi, Masayoshi

    2013-10-01

    Arbuscular mycorrhizal symbiosis (AMS) and root nodule symbiosis (RNS) are mutualistic plant-microbe interactions that confer nutritional benefits to both partners. Leguminous plants possess a common genetic system for intracellular symbiosis with AM fungi and with rhizobia. Here we show that CERBERUS and NSP1, which respectively encode an E3 ubiquitin ligase and a GRAS transcriptional regulator and which have previously only been implicated in RNS, are involved in AM fungal infection in Lotus japonicus. Hyphal elongation along the longitudinal axis of the root was reduced in the cerberus mutant, giving rise to a lower colonization level. Knockout of NSP1 decreased the frequency of plants colonized by AM fungi or rhizobia. CERBERUS and NSP1 showed different patterns of expression in response to infection with symbiotic microbes. A low constitutive level of CERBERUS expression was observed in the root and an increased level of NSP1 expression was detected in arbuscule-containing cells. Induction of AM marker gene was triggered in both cerberus and nsp1 mutants by infection with symbiotic microbes; however, the mutants showed a weaker induction of marker gene expression than the wild type, mirroring their lower level of colonization. The common symbiosis genes are believed to act in an early signaling pathway for recognition of symbionts and for triggering early symbiotic responses. Our quantitative analysis of symbiotic phenotypes revealed developmental defects of the novel common symbiosis mutants in both symbioses, which demonstrates that common symbiosis mechanisms also contribute to a range of functions at later or different stages of symbiont infection.

  5. Périgord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis.

    PubMed

    Martin, Francis; Kohler, Annegret; Murat, Claude; Balestrini, Raffaella; Coutinho, Pedro M; Jaillon, Olivier; Montanini, Barbara; Morin, Emmanuelle; Noel, Benjamin; Percudani, Riccardo; Porcel, Bettina; Rubini, Andrea; Amicucci, Antonella; Amselem, Joelle; Anthouard, Véronique; Arcioni, Sergio; Artiguenave, François; Aury, Jean-Marc; Ballario, Paola; Bolchi, Angelo; Brenna, Andrea; Brun, Annick; Buée, Marc; Cantarel, Brandi; Chevalier, Gérard; Couloux, Arnaud; Da Silva, Corinne; Denoeud, France; Duplessis, Sébastien; Ghignone, Stefano; Hilselberger, Benoît; Iotti, Mirco; Marçais, Benoît; Mello, Antonietta; Miranda, Michele; Pacioni, Giovanni; Quesneville, Hadi; Riccioni, Claudia; Ruotolo, Roberta; Splivallo, Richard; Stocchi, Vilberto; Tisserant, Emilie; Viscomi, Arturo Roberto; Zambonelli, Alessandra; Zampieri, Elisa; Henrissat, Bernard; Lebrun, Marc-Henri; Paolocci, Francesco; Bonfante, Paola; Ottonello, Simone; Wincker, Patrick

    2010-04-15

    The Périgord black truffle (Tuber melanosporum Vittad.) and the Piedmont white truffle dominate today's truffle market. The hypogeous fruiting body of T. melanosporum is a gastronomic delicacy produced by an ectomycorrhizal symbiont endemic to calcareous soils in southern Europe. The worldwide demand for this truffle has fuelled intense efforts at cultivation. Identification of processes that condition and trigger fruit body and symbiosis formation, ultimately leading to efficient crop production, will be facilitated by a thorough analysis of truffle genomic traits. In the ectomycorrhizal Laccaria bicolor, the expansion of gene families may have acted as a 'symbiosis toolbox'. This feature may however reflect evolution of this particular taxon and not a general trait shared by all ectomycorrhizal species. To get a better understanding of the biology and evolution of the ectomycorrhizal symbiosis, we report here the sequence of the haploid genome of T. melanosporum, which at approximately 125 megabases is the largest and most complex fungal genome sequenced so far. This expansion results from a proliferation of transposable elements accounting for approximately 58% of the genome. In contrast, this genome only contains approximately 7,500 protein-coding genes with very rare multigene families. It lacks large sets of carbohydrate cleaving enzymes, but a few of them involved in degradation of plant cell walls are induced in symbiotic tissues. The latter feature and the upregulation of genes encoding for lipases and multicopper oxidases suggest that T. melanosporum degrades its host cell walls during colonization. Symbiosis induces an increased expression of carbohydrate and amino acid transporters in both L. bicolor and T. melanosporum, but the comparison of genomic traits in the two ectomycorrhizal fungi showed that genetic predispositions for symbiosis-'the symbiosis toolbox'-evolved along different ways in ascomycetes and basidiomycetes. PMID:20348908

  6. Heritable symbiosis: The advantages and perils of an evolutionary rabbit hole.

    PubMed

    Bennett, Gordon M; Moran, Nancy A

    2015-08-18

    Many eukaryotes have obligate associations with microorganisms that are transmitted directly between generations. A model for heritable symbiosis is the association of aphids, a clade of sap-feeding insects, and Buchnera aphidicola, a gammaproteobacterium that colonized an aphid ancestor 150 million years ago and persists in almost all 5,000 aphid species. Symbiont acquisition enables evolutionary and ecological expansion; aphids are one of many insect groups that would not exist without heritable symbiosis. Receiving less attention are potential negative ramifications of symbiotic alliances. In the short run, symbionts impose metabolic costs. Over evolutionary time, hosts evolve dependence beyond the original benefits of the symbiosis. Symbiotic partners enter into an evolutionary spiral that leads to irreversible codependence and associated risks. Host adaptations to symbiosis (e.g., immune-system modification) may impose vulnerabilities. Symbiont genomes also continuously accumulate deleterious mutations, limiting their beneficial contributions and environmental tolerance. Finally, the fitness interests of obligate heritable symbionts are distinct from those of their hosts, leading to selfish tendencies. Thus, genes underlying the host-symbiont interface are predicted to follow a coevolutionary arms race, as observed for genes governing host-pathogen interactions. On the macroevolutionary scale, the rapid evolution of interacting symbiont and host genes is predicted to accelerate host speciation rates by generating genetic incompatibilities. However, degeneration of symbiont genomes may ultimately limit the ecological range of host species, potentially increasing extinction risk. Recent results for the aphid-Buchnera symbiosis and related systems illustrate that, whereas heritable symbiosis can expand ecological range and spur diversification, it also presents potential perils.

  7. Location and Survival of Mycorrhiza Helper Pseudomonas fluorescens during Establishment of Ectomycorrhizal Symbiosis between Laccaria bicolor and Douglas Fir

    PubMed Central

    Frey-Klett, P.; Pierrat, J. C.; Garbaye, J.

    1997-01-01

    The mycorrhiza helper bacterium Pseudomonas fluorescens BBc6, isolated from a Laccaria bicolor sporocarp, consistently promotes L. bicolor-Douglas fir (Pseudotsuga menziesii) ectomycorrhizal formation, even with low doses of bacterial inoculum. In order to describe this phenomenon more accurately, we have looked at the location and survival of the introduced bacterial strain in the soil and in the rhizosphere during the establishment of mycorrhizal symbiosis in glasshouse and nursery experiments. Bacterial populations were quantified with a spontaneous, stable, rifampin-resistant mutant, BBc6R8, which phenotypically conformed to the parental strain. BBc6R8 populations declined rapidly, reaching the detection limit after 19 weeks, and did not increase either when L. bicolor sporocarps were forming in autumn or when Douglas fir roots resumed growing in spring. BBc6R8 was neither an endophyte nor a rhizobacterium. Furthermore, it was not particularly associated with either mycorrhizas of Douglas fir-L. bicolor or L. bicolor sporocarps. Surprisingly, a significant mycorrhiza helper effect was observed when the inoculated BBc6R8 population had dropped as low as 30 CFU g of dry matter(sup-1) in the soil. This study raises questions concerning the bacterial concentration in the soil which is effective for promotion of mycorrhizal establishment and the timing of the bacterial effect. It allows us to develop working hypotheses, which can be tested experimentally, to identify the mechanisms of the mycorrhiza helper effect. PMID:16535478

  8. Litter-forager termite mounds enhance the ectomycorrhizal symbiosis between Acacia holosericea A. Cunn. Ex G. Don and Scleroderma dictyosporum isolates.

    PubMed

    Duponnois, Robin; Assikbetse, Komi; Ramanankierana, Heriniaina; Kisa, Marija; Thioulouse, Jean; Lepage, Michel

    2006-05-01

    The hypothesis of the present study was that the termite mounds of Macrotermes subhyalinus (MS) (a litter-forager termite) were inhabited by a specific microflora that could enhance with the ectomycorrhizal fungal development. We tested the effect of this feeding group mound material on (i) the ectomycorrhization symbiosis between Acacia holosericea (an Australian Acacia introduced in the sahelian areas) and two ectomycorrhizal fungal isolates of Scleroderma dictyosporum (IR408 and IR412) in greenhouse conditions, (ii) the functional diversity of soil microflora and (iii) the diversity of fluorescent pseudomonads. The results showed that the termite mound amendment significantly increased the ectomycorrhizal expansion. MS mound amendment and ectomycorrhizal inoculation induced strong modifications of the soil functional microbial diversity by promoting the multiplication of carboxylic acid catabolizing microorganisms. The phylogenetic analysis showed that fluorescent pseudomonads mostly belong to the Pseudomonads monteillii species. One of these, P. monteillii isolate KR9, increased the ectomycorrhizal development between S. dictyosporum IR412 and A. holosericea. The occurrence of MS termite mounds could be involved in the expansion of ectomycorrhizal symbiosis and could be implicated in nutrient flow and local diversity.

  9. Evaluating industrial symbiosis and algae cultivation from a life cycle perspective.

    PubMed

    Soratana, Kullapa; Landis, Amy E

    2011-07-01

    A comparative life cycle assessment (LCA) was conducted on 20 scenarios of microalgae cultivation. These scenarios examined the utilization of nutrients and CO(2) from synthetic sources and waste streams as well as the materials used to construct a photobioreactor (PBR). A 0.2-m(3) closed PBR of Chlorella vulgaris at 30%-oil content by weight with the productivity of 25 g/m(2) × day was used as a case study. Results of the study show that the utilization of resources from waste streams mainly avoided global warming potential (GWP) and eutrophication impacts. Impacts from the production of material used to construct the PBR dominate total impacts in acidification and ozone depletion categories, even over longer PBR lifetimes; thus, the choice of PBR construction materials is important.

  10. Insights on the Impact of Arbuscular Mycorrhizal Symbiosis on Tomato Tolerance to Water Stress.

    PubMed

    Chitarra, Walter; Pagliarani, Chiara; Maserti, Biancaelena; Lumini, Erica; Siciliano, Ilenia; Cascone, Pasquale; Schubert, Andrea; Gambino, Giorgio; Balestrini, Raffaella; Guerrieri, Emilio

    2016-06-01

    Arbuscular mycorrhizal (AM) fungi, which form symbioses with the roots of the most important crop species, are usually considered biofertilizers, whose exploitation could represent a promising avenue for the development in the future of a more sustainable next-generation agriculture. The best understood function in symbiosis is an improvement in plant mineral nutrient acquisition, as exchange for carbon compounds derived from the photosynthetic process: this can enhance host growth and tolerance to environmental stresses, such as water stress (WS). However, physiological and molecular mechanisms occurring in arbuscular mycorrhiza-colonized plants and directly involved in the mitigation of WS effects need to be further investigated. The main goal of this work is to verify the potential impact of AM symbiosis on the plant response to WS To this aim, the effect of two AM fungi (Funneliformis mosseae and Rhizophagus intraradices) on tomato (Solanum lycopersicum) under the WS condition was studied. A combined approach, involving ecophysiological, morphometric, biochemical, and molecular analyses, has been used to highlight the mechanisms involved in plant response to WS during AM symbiosis. Gene expression analyses focused on a set of target genes putatively involved in the plant response to drought, and in parallel, we considered the expression changes induced by the imposed stress on a group of fungal genes playing a key role in the water-transport process. Taken together, the results show that AM symbiosis positively affects the tolerance to WS in tomato, with a different plant response depending on the AM fungi species involved. PMID:27208301

  11. Role of Hfq in an animal-microbe symbiosis under simulated microgravity conditions

    NASA Astrophysics Data System (ADS)

    Grant, Kyle C.; Khodadad, Christina L. M.; Foster, Jamie S.

    2014-01-01

    Microgravity has a profound impact on the physiology of pathogenic microbes; however, its effects on mutualistic microbes are relatively unknown. To examine the effects of microgravity on those beneficial microbes that associate with animal tissues, we used the symbiosis between the bobtail squid Euprymna scolopes and a motile, luminescent bacterium, Vibrio fischeri as a model system. Specifically, we examined the role of Hfq, an RNA-binding protein known to be an important global regulator under space flight conditions, in the squid-vibrio symbiosis under simulated microgravity. To mimic a reduced gravity environment, the symbiotic partners were co-incubated in high-aspect-ratio rotating wall vessel bioreactors and examined at various stages of development. Results indicated that under simulated microgravity, hfq expression was down-regulated in V. fischeri. A mutant strain defective in hfq showed no colonization phenotype, indicating that Hfq was not required to initiate the symbiosis with the host squid. However, the hfq mutant showed attenuated levels of apoptotic cell death, a key symbiosis phenotype, within the host light organ suggesting that Hfq does contribute to normal light organ morphogenesis. Results also indicated that simulated microgravity conditions accelerated the onset of cell death in wild-type cells but not in the hfq mutant strains. These data suggest that Hfq plays an important role in the mutualism between V. fischeri and its animal host and that its expression can be negatively impacted by simulated microgravity conditions.

  12. Effects of nano-ZnO on the agronomically relevant Rhizobium-legume symbiosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of nano-ZnO (nZnO) on Rhizobium-legume symbiosis was studied with garden pea and its compatible bacterial partner Rhizobium leguminosarum bv. viciae 3841. Exposure of peas to nZnO had no impact on germination, but significantly affected root length. Chronic exposure of plant to nZnO impac...

  13. The effect of pseudo-microgravity on the symbiosis of plants and microorganisms

    NASA Astrophysics Data System (ADS)

    Tomita-Yokotani, Kaori; Maki, Asano; Aoki, Toshio; Tamura, Kenji; Wada, Hidenori; Hashimoto, Hirofumi; Yamashita, Masamichi

    The symbiosis of plants and microorganisms is important to conduct agriculture under space environment. However, we have less knowledge on whether this kind of symbiosis can be established under space condition. We examined the functional compounds responsible to symbiosis between rhizobiaum and Lotus japonicus as a model of symbiotic combination. The existence of the substances for their symbiosis, some flavonoids, have already been known from the study of gene expression, but the detail structures have not yet been elucidated. Pseudomicrogravity was generated by the 3D-clinorotation. Twenty flavonoids were found in the extracts of 16 days plants of Lotus japonicus grown under the normal gravity by HPLC. Content of two flavonoids among them was affected by the infection of Mesorhizobium loti to them. It has a possibility that the two flavonoids were key substances for their combination process. The productions of those flavonoids were confirmed also under the pseudo-microgravity. The amount of one flavonoid was increased by both infection of rhizobium and exposure to the normal and pseudo-micro gravity. Chemical species of these flavonoids were identified by LC- ESI/MS and spectroscopic analysis. To show the effects of pseudo-microgravity on the gene expression, enzymic activities related to the functional compounds are evaluated after the rhizobial infection.

  14. Effects of nano-TiO2 on the agronomically-relevant Rhizobium-legume symbiosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of nano-TiO2 on Rhizobium-legume symbiosis was studied using garden peas and the compatible bacterial partner Rhizobium leguminosarum bv. viciae 3841. Exposure to nano-TiO2 did not affect the germination of peas grown aseptically, nor did it impact the gross root structure. However, nano-...

  15. [Effect of five fungicides on growth of Glycyrrhiza uralensis and efficiency of mycorrhizal symbiosis].

    PubMed

    Li, Peng-ying; Yang, Guang; Zhou, Xiu-teng; Zhou, Liane-yun; Shao, Ai-juan; Chen, Mei-lan

    2015-12-01

    In order to obtain the fungicides with minimal impact on efficiency of mycorrhizal symbiosis, the effect of five fungicides including polyoxins, jinggangmycins, thiophanate methylate, chlorothalonil and carbendazim on the growth of medicinal plant and efficiency of mycorrhizal symbiosis were studied. Pot cultured Glycyrrhiza uralensis was treated with different fungicides with the concentration that commonly used in the field. 60 d after treated with fungicides, infection rate, infection density, biomass indexes, photosyn- thetic index and the content of active component were measured. Experimental results showed that carbendazim had the strongest inhibition on mycorrhizal symbiosis effect. Carbendazim significantly inhibited the mycorrhizal infection rate, significantly suppressed the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. Polyoxins showed the lowest inhibiting affection. Polyoxins had no significant effect on mycorrhizal infection rate, the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. The other three fungicides also had an inhibitory effect on efficiency of mycorrhizal symbiosis, and the inhibition degrees were all between polyoxins's and carbendazim's. The author considered that fungicide's inhibition degree on mycorrhizal effect might be related with the species of fungicides, so the author suggested that the farmer should try to choose bio-fungicides like polyoxins.

  16. Mixed Nodule Infection in Sinorhizobium meliloti–Medicago sativa Symbiosis Suggest the Presence of Cheating Behavior

    PubMed Central

    Checcucci, Alice; Azzarello, Elisa; Bazzicalupo, Marco; Galardini, Marco; Lagomarsino, Alessandra; Mancuso, Stefano; Marti, Lucia; Marzano, Maria C.; Mocali, Stefano; Squartini, Andrea; Zanardo, Marina; Mengoni, Alessio

    2016-01-01

    In the symbiosis between rhizobia and legumes, host plants can form symbiotic root nodules with multiple rhizobial strains, potentially showing different symbiotic performances in nitrogen fixation. Here, we investigated the presence of mixed nodules, containing rhizobia with different degrees of mutualisms, and evaluate their relative fitness in the Sinorhizobium meliloti–Medicago sativa model symbiosis. We used three S. meliloti strains, the mutualist strains Rm1021 and BL225C and the non-mutualist AK83. We performed competition experiments involving both in vitro and in vivo symbiotic assays with M. sativa host plants. We show the occurrence of a high number (from 27 to 100%) of mixed nodules with no negative effect on both nitrogen fixation and plant growth. The estimation of the relative fitness as non-mutualist/mutualist ratios in single nodules shows that in some nodules the non-mutualist strain efficiently colonized root nodules along with the mutualist ones. In conclusion, we can support the hypothesis that in S. meliloti–M. sativa symbiosis mixed nodules are formed and allow non-mutualist or less-mutualist bacterial partners to be less or not sanctioned by the host plant, hence allowing a potential form of cheating behavior to be present in the nitrogen fixing symbiosis. PMID:27379128

  17. Mixed Nodule Infection in Sinorhizobium meliloti-Medicago sativa Symbiosis Suggest the Presence of Cheating Behavior.

    PubMed

    Checcucci, Alice; Azzarello, Elisa; Bazzicalupo, Marco; Galardini, Marco; Lagomarsino, Alessandra; Mancuso, Stefano; Marti, Lucia; Marzano, Maria C; Mocali, Stefano; Squartini, Andrea; Zanardo, Marina; Mengoni, Alessio

    2016-01-01

    In the symbiosis between rhizobia and legumes, host plants can form symbiotic root nodules with multiple rhizobial strains, potentially showing different symbiotic performances in nitrogen fixation. Here, we investigated the presence of mixed nodules, containing rhizobia with different degrees of mutualisms, and evaluate their relative fitness in the Sinorhizobium meliloti-Medicago sativa model symbiosis. We used three S. meliloti strains, the mutualist strains Rm1021 and BL225C and the non-mutualist AK83. We performed competition experiments involving both in vitro and in vivo symbiotic assays with M. sativa host plants. We show the occurrence of a high number (from 27 to 100%) of mixed nodules with no negative effect on both nitrogen fixation and plant growth. The estimation of the relative fitness as non-mutualist/mutualist ratios in single nodules shows that in some nodules the non-mutualist strain efficiently colonized root nodules along with the mutualist ones. In conclusion, we can support the hypothesis that in S. meliloti-M. sativa symbiosis mixed nodules are formed and allow non-mutualist or less-mutualist bacterial partners to be less or not sanctioned by the host plant, hence allowing a potential form of cheating behavior to be present in the nitrogen fixing symbiosis. PMID:27379128

  18. [Effect of five fungicides on growth of Glycyrrhiza uralensis and efficiency of mycorrhizal symbiosis].

    PubMed

    Li, Peng-ying; Yang, Guang; Zhou, Xiu-teng; Zhou, Liane-yun; Shao, Ai-juan; Chen, Mei-lan

    2015-12-01

    In order to obtain the fungicides with minimal impact on efficiency of mycorrhizal symbiosis, the effect of five fungicides including polyoxins, jinggangmycins, thiophanate methylate, chlorothalonil and carbendazim on the growth of medicinal plant and efficiency of mycorrhizal symbiosis were studied. Pot cultured Glycyrrhiza uralensis was treated with different fungicides with the concentration that commonly used in the field. 60 d after treated with fungicides, infection rate, infection density, biomass indexes, photosyn- thetic index and the content of active component were measured. Experimental results showed that carbendazim had the strongest inhibition on mycorrhizal symbiosis effect. Carbendazim significantly inhibited the mycorrhizal infection rate, significantly suppressed the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. Polyoxins showed the lowest inhibiting affection. Polyoxins had no significant effect on mycorrhizal infection rate, the actual photosynthetic efficiency of G. uralensis and the most indicators of biomass. The other three fungicides also had an inhibitory effect on efficiency of mycorrhizal symbiosis, and the inhibition degrees were all between polyoxins's and carbendazim's. The author considered that fungicide's inhibition degree on mycorrhizal effect might be related with the species of fungicides, so the author suggested that the farmer should try to choose bio-fungicides like polyoxins. PMID:27141668

  19. The promiscuous larvae: flexibility in the establishment of symbiosis in corals

    NASA Astrophysics Data System (ADS)

    Cumbo, V. R.; Baird, A. H.; van Oppen, M. J. H.

    2013-03-01

    Coral reefs thrive in part because of the symbiotic partnership between corals and Symbiodinium. While this partnership is one of the keys to the success of coral reef ecosystems, surprisingly little is known about many aspects of coral symbiosis, in particular the establishment and development of symbiosis in host species that acquire symbionts anew in each generation. More specifically, the point at which symbiosis is established (i.e., larva vs. juvenile) remains uncertain, as does the source of free-living Symbiodinium in the environment. In addition, the capacity of host and symbiont to form novel combinations is unknown. To explore patterns of initial association between host and symbiont, larvae of two species of Acropora were exposed to sediment collected from three locations on the Great Barrier Reef. A high proportion of larvae established symbiosis shortly after contact with sediments, and Acropora larvae were promiscuous, taking up multiple types of Symbiodinium. The Symbiodinium types acquired from the sediments reflected the symbiont assemblage within a wide range of cnidarian hosts at each of the three sites, suggesting potential regional differences in the free-living Symbiodinium assemblage. Coral larvae clearly have the capacity to take up Symbiodinium prior to settlement, and sediment is a likely source. Promiscuous larvae allow species to associate with Symbiodinium appropriate for potentially novel environments that may be experienced following dispersal.

  20. Insights on the Impact of Arbuscular Mycorrhizal Symbiosis on Tomato Tolerance to Water Stress1[OPEN

    PubMed Central

    Siciliano, Ilenia

    2016-01-01

    Arbuscular mycorrhizal (AM) fungi, which form symbioses with the roots of the most important crop species, are usually considered biofertilizers, whose exploitation could represent a promising avenue for the development in the future of a more sustainable next-generation agriculture. The best understood function in symbiosis is an improvement in plant mineral nutrient acquisition, as exchange for carbon compounds derived from the photosynthetic process: this can enhance host growth and tolerance to environmental stresses, such as water stress (WS). However, physiological and molecular mechanisms occurring in arbuscular mycorrhiza-colonized plants and directly involved in the mitigation of WS effects need to be further investigated. The main goal of this work is to verify the potential impact of AM symbiosis on the plant response to WS. To this aim, the effect of two AM fungi (Funneliformis mosseae and Rhizophagus intraradices) on tomato (Solanum lycopersicum) under the WS condition was studied. A combined approach, involving ecophysiological, morphometric, biochemical, and molecular analyses, has been used to highlight the mechanisms involved in plant response to WS during AM symbiosis. Gene expression analyses focused on a set of target genes putatively involved in the plant response to drought, and in parallel, we considered the expression changes induced by the imposed stress on a group of fungal genes playing a key role in the water-transport process. Taken together, the results show that AM symbiosis positively affects the tolerance to WS in tomato, with a different plant response depending on the AM fungi species involved. PMID:27208301

  1. Mixed Nodule Infection in Sinorhizobium meliloti-Medicago sativa Symbiosis Suggest the Presence of Cheating Behavior.

    PubMed

    Checcucci, Alice; Azzarello, Elisa; Bazzicalupo, Marco; Galardini, Marco; Lagomarsino, Alessandra; Mancuso, Stefano; Marti, Lucia; Marzano, Maria C; Mocali, Stefano; Squartini, Andrea; Zanardo, Marina; Mengoni, Alessio

    2016-01-01

    In the symbiosis between rhizobia and legumes, host plants can form symbiotic root nodules with multiple rhizobial strains, potentially showing different symbiotic performances in nitrogen fixation. Here, we investigated the presence of mixed nodules, containing rhizobia with different degrees of mutualisms, and evaluate their relative fitness in the Sinorhizobium meliloti-Medicago sativa model symbiosis. We used three S. meliloti strains, the mutualist strains Rm1021 and BL225C and the non-mutualist AK83. We performed competition experiments involving both in vitro and in vivo symbiotic assays with M. sativa host plants. We show the occurrence of a high number (from 27 to 100%) of mixed nodules with no negative effect on both nitrogen fixation and plant growth. The estimation of the relative fitness as non-mutualist/mutualist ratios in single nodules shows that in some nodules the non-mutualist strain efficiently colonized root nodules along with the mutualist ones. In conclusion, we can support the hypothesis that in S. meliloti-M. sativa symbiosis mixed nodules are formed and allow non-mutualist or less-mutualist bacterial partners to be less or not sanctioned by the host plant, hence allowing a potential form of cheating behavior to be present in the nitrogen fixing symbiosis.

  2. A model symbiosis reveals a role for sheathed-flagellum rotation in the release of immunogenic lipopolysaccharide

    PubMed Central

    Brennan, Caitlin A; Hunt, Jason R; Kremer, Natacha; Krasity, Benjamin C; Apicella, Michael A; McFall-Ngai, Margaret J; Ruby, Edward G

    2014-01-01

    Bacterial flagella mediate host–microbe interactions through tissue tropism during colonization, as well as by activating immune responses. The flagellar shaft of some bacteria, including several human pathogens, is encased in a membranous sheath of unknown function. While it has been hypothesized that the sheath may allow these bacteria to evade host responses to the immunogenic flagellin subunit, this unusual structural feature has remained an enigma. Here we demonstrate that the rotation of the sheathed flagellum in both the mutualist Vibrio fischeri and the pathogen Vibrio cholerae promotes release of a potent bacteria-derived immunogen, lipopolysaccharide, found in the flagellar sheath. We further present a new role for the flagellar sheath in triggering, rather than circumventing, host immune responses in the model squid-vibrio symbiosis. Such an observation not only has implications for the study of bacterial pathogens with sheathed flagella, but also raises important biophysical questions of sheathed-flagellum function. DOI: http://dx.doi.org/10.7554/eLife.01579.001 PMID:24596150

  3. Metal toxicity differently affects the Iris pseudacorus-arbuscular mycorrhiza fungi symbiosis in terrestrial and semi-aquatic habitats.

    PubMed

    Wężowicz, K; Turnau, K; Anielska, T; Zhebrak, I; Gołuszka, K; Błaszkowski, J; Rozpądek, P

    2015-12-01

    Phytoremediation offers an environmental friendly alternative to conventional cleanup techniques. In this study, mycorrhizal fungi isolated from the roots of Mentha longifolia grown in the basin of the Centuria River (S Poland) were used. Iris pseudacorus was grown in substratum from an industrial waste, enriched in Pb, Fe, Zn, and Cd in a terrestrial and water-logged habitat. Plant yield and photosynthetic performance was the highest in the aquatic environment; however, the presence of toxic metals (TM) negatively affected photosystem II (PSII) photochemistry as shown by the JIP test. Fungi colonization and Cd accumulation within plant tissues was decreased. In the terrestrial habitat, neither arbuscular mycorrhizal fungi (AMF) nor metal toxicity affected plant growth, although metal uptake, Cd in particular, as well as photosynthesis were affected. Inoculated plants accumulated significantly more Cd, and photosynthesis was downregulated. The results presented in this study clearly indicate that the I. pseudacorus-AMF symbiosis adapts itself to the presence of toxic metals in the environment, optimizing resource supply, energy fluxes, and possibly stress tolerance mechanisms. Plant/AMF consortia grown in terrestrial and water-logged habitats utilize different strategies to cope with metal toxicity. The use of AMF in improving the phytoremediation potential of I. pseudacorus needs, however, further research.

  4. Metal toxicity differently affects the Iris pseudacorus-arbuscular mycorrhiza fungi symbiosis in terrestrial and semi-aquatic habitats.

    PubMed

    Wężowicz, K; Turnau, K; Anielska, T; Zhebrak, I; Gołuszka, K; Błaszkowski, J; Rozpądek, P

    2015-12-01

    Phytoremediation offers an environmental friendly alternative to conventional cleanup techniques. In this study, mycorrhizal fungi isolated from the roots of Mentha longifolia grown in the basin of the Centuria River (S Poland) were used. Iris pseudacorus was grown in substratum from an industrial waste, enriched in Pb, Fe, Zn, and Cd in a terrestrial and water-logged habitat. Plant yield and photosynthetic performance was the highest in the aquatic environment; however, the presence of toxic metals (TM) negatively affected photosystem II (PSII) photochemistry as shown by the JIP test. Fungi colonization and Cd accumulation within plant tissues was decreased. In the terrestrial habitat, neither arbuscular mycorrhizal fungi (AMF) nor metal toxicity affected plant growth, although metal uptake, Cd in particular, as well as photosynthesis were affected. Inoculated plants accumulated significantly more Cd, and photosynthesis was downregulated. The results presented in this study clearly indicate that the I. pseudacorus-AMF symbiosis adapts itself to the presence of toxic metals in the environment, optimizing resource supply, energy fluxes, and possibly stress tolerance mechanisms. Plant/AMF consortia grown in terrestrial and water-logged habitats utilize different strategies to cope with metal toxicity. The use of AMF in improving the phytoremediation potential of I. pseudacorus needs, however, further research. PMID:26585452

  5. The bifunctional plant receptor, OsCERK1, regulates both chitin-triggered immunity and arbuscular mycorrhizal symbiosis in rice.

    PubMed

    Miyata, Kana; Kozaki, Toshinori; Kouzai, Yusuke; Ozawa, Kenjirou; Ishii, Kazuo; Asamizu, Erika; Okabe, Yoshihiro; Umehara, Yosuke; Miyamoto, Ayano; Kobae, Yoshihiro; Akiyama, Kohki; Kaku, Hanae; Nishizawa, Yoko; Shibuya, Naoto; Nakagawa, Tomomi

    2014-11-01

    Plants are constantly exposed to threats from pathogenic microbes and thus developed an innate immune system to protect themselves. On the other hand, many plants also have the ability to establish endosymbiosis with beneficial microbes such as arbuscular mycorrhizal (AM) fungi or rhizobial bacteria, which improves the growth of host plants. How plants evolved these systems managing such opposite plant-microbe interactions is unclear. We show here that knockout (KO) mutants of OsCERK1, a rice receptor kinase essential for chitin signaling, were impaired not only for chitin-triggered defense responses but also for AM symbiosis, indicating the bifunctionality of OsCERK1 in defense and symbiosis. On the other hand, a KO mutant of OsCEBiP, which forms a receptor complex with OsCERK1 and is essential for chitin-triggered immunity, established mycorrhizal symbiosis normally. Therefore, OsCERK1 but not chitin-triggered immunity is required for AM symbiosis. Furthermore, experiments with chimeric receptors showed that the kinase domains of OsCERK1 and homologs from non-leguminous, mycorrhizal plants could trigger nodulation signaling in legume-rhizobium interactions as the kinase domain of Nod factor receptor1 (NFR1), which is essential for triggering the nodulation program in leguminous plants, did. Because leguminous plants are believed to have developed the rhizobial symbiosis on the basis of AM symbiosis, our results suggest that the symbiotic function of ancestral CERK1 in AM symbiosis enabled the molecular evolution to leguminous NFR1 and resulted in the establishment of legume-rhizobia symbiosis. These results also suggest that OsCERK1 and homologs serve as a molecular switch that activates defense or symbiotic responses depending on the infecting microbes. PMID:25231970

  6. The bifunctional plant receptor, OsCERK1, regulates both chitin-triggered immunity and arbuscular mycorrhizal symbiosis in rice.

    PubMed

    Miyata, Kana; Kozaki, Toshinori; Kouzai, Yusuke; Ozawa, Kenjirou; Ishii, Kazuo; Asamizu, Erika; Okabe, Yoshihiro; Umehara, Yosuke; Miyamoto, Ayano; Kobae, Yoshihiro; Akiyama, Kohki; Kaku, Hanae; Nishizawa, Yoko; Shibuya, Naoto; Nakagawa, Tomomi

    2014-11-01

    Plants are constantly exposed to threats from pathogenic microbes and thus developed an innate immune system to protect themselves. On the other hand, many plants also have the ability to establish endosymbiosis with beneficial microbes such as arbuscular mycorrhizal (AM) fungi or rhizobial bacteria, which improves the growth of host plants. How plants evolved these systems managing such opposite plant-microbe interactions is unclear. We show here that knockout (KO) mutants of OsCERK1, a rice receptor kinase essential for chitin signaling, were impaired not only for chitin-triggered defense responses but also for AM symbiosis, indicating the bifunctionality of OsCERK1 in defense and symbiosis. On the other hand, a KO mutant of OsCEBiP, which forms a receptor complex with OsCERK1 and is essential for chitin-triggered immunity, established mycorrhizal symbiosis normally. Therefore, OsCERK1 but not chitin-triggered immunity is required for AM symbiosis. Furthermore, experiments with chimeric receptors showed that the kinase domains of OsCERK1 and homologs from non-leguminous, mycorrhizal plants could trigger nodulation signaling in legume-rhizobium interactions as the kinase domain of Nod factor receptor1 (NFR1), which is essential for triggering the nodulation program in leguminous plants, did. Because leguminous plants are believed to have developed the rhizobial symbiosis on the basis of AM symbiosis, our results suggest that the symbiotic function of ancestral CERK1 in AM symbiosis enabled the molecular evolution to leguminous NFR1 and resulted in the establishment of legume-rhizobia symbiosis. These results also suggest that OsCERK1 and homologs serve as a molecular switch that activates defense or symbiotic responses depending on the infecting microbes.

  7. Symbiosis of sea anemones and hermit crabs: different resource utilization patterns in the Aegean Sea

    NASA Astrophysics Data System (ADS)

    Vafeiadou, Anna-Maria; Antoniadou, Chryssanthi; Chintiroglou, Chariton

    2012-09-01

    The small-scale distribution and resource utilization patterns of hermit crabs living in symbiosis with sea anemones were investigated in the Aegean Sea. Four hermit crab species, occupying shells of nine gastropod species, were found in symbiosis with the sea anemone Calliactis parasitica. Shell resource utilization patterns varied among hermit crabs, with Dardanus species utilizing a wide variety of shells. The size structure of hermit crab populations also affected shell resource utilization, with small-sized individuals inhabiting a larger variety of shells. Sea anemone utilization patterns varied both among hermit crab species and among residence shells, with larger crabs and shells hosting an increased abundance and biomass of C. parasitica. The examined biometric relationships suggested that small-sized crabs carry, proportionally to their weight, heavier shells and increased anemone biomass than larger ones. Exceptions to the above patterns are related either to local resource availability or to other environmental factors.

  8. Symbiosis with Francisella tularensis provides resistance to pathogens in the silkworm.

    PubMed

    Suzuki, Jin; Uda, Akihiko; Watanabe, Kenta; Shimizu, Takashi; Watarai, Masahisa

    2016-01-01

    Francisella tularensis, the causative agent of tularemia, is a highly virulent facultative intracellular pathogen found in a wide range of animals, including arthropods, and environments. This bacterium has been known for over 100 years, but the lifestyle of F. tularensis in natural reservoirs remains largely unknown. Thus, we established a novel natural host model for F. tularensis using the silkworm (Bombyx mori), which is an insect model for infection by pathogens. F. tularensis established a symbiosis with silkworms, and bacteria were observed in the hemolymph. After infection with F. tularensis, the induction of melanization and nodulation, which are immune responses to bacterial infection, were inhibited in silkworms. Pre-inoculation of silkworms with F. tularensis enhanced the expression of antimicrobial peptides and resistance to infection by pathogenic bacteria. These results suggest that silkworms acquire host resistance via their symbiosis with F. tularensis, which may have important fitness benefits in natural reservoirs. PMID:27507264

  9. Convergent losses of decay mechanisms and rapid turnover of symbiosis genes in mycorrhizal mutualists.

    PubMed

    Kohler, Annegret; Kuo, Alan; Nagy, Laszlo G; Morin, Emmanuelle; Barry, Kerrie W; Buscot, Francois; Canbäck, Björn; Choi, Cindy; Cichocki, Nicolas; Clum, Alicia; Colpaert, Jan; Copeland, Alex; Costa, Mauricio D; Doré, Jeanne; Floudas, Dimitrios; Gay, Gilles; Girlanda, Mariangela; Henrissat, Bernard; Herrmann, Sylvie; Hess, Jaqueline; Högberg, Nils; Johansson, Tomas; Khouja, Hassine-Radhouane; LaButti, Kurt; Lahrmann, Urs; Levasseur, Anthony; Lindquist, Erika A; Lipzen, Anna; Marmeisse, Roland; Martino, Elena; Murat, Claude; Ngan, Chew Y; Nehls, Uwe; Plett, Jonathan M; Pringle, Anne; Ohm, Robin A; Perotto, Silvia; Peter, Martina; Riley, Robert; Rineau, Francois; Ruytinx, Joske; Salamov, Asaf; Shah, Firoz; Sun, Hui; Tarkka, Mika; Tritt, Andrew; Veneault-Fourrey, Claire; Zuccaro, Alga; Tunlid, Anders; Grigoriev, Igor V; Hibbett, David S; Martin, Francis

    2015-04-01

    To elucidate the genetic bases of mycorrhizal lifestyle evolution, we sequenced new fungal genomes, including 13 ectomycorrhizal (ECM), orchid (ORM) and ericoid (ERM) species, and five saprotrophs, which we analyzed along with other fungal genomes. Ectomycorrhizal fungi have a reduced complement of genes encoding plant cell wall-degrading enzymes (PCWDEs), as compared to their ancestral wood decayers. Nevertheless, they have retained a unique array of PCWDEs, thus suggesting that they possess diverse abilities to decompose lignocellulose. Similar functional categories of nonorthologous genes are induced in symbiosis. Of induced genes, 7-38% are orphan genes, including genes that encode secreted effector-like proteins. Convergent evolution of the mycorrhizal habit in fungi occurred via the repeated evolution of a 'symbiosis toolkit', with reduced numbers of PCWDEs and lineage-specific suites of mycorrhiza-induced genes.

  10. Symbiosis with Francisella tularensis provides resistance to pathogens in the silkworm

    PubMed Central

    Suzuki, Jin; Uda, Akihiko; Watanabe, Kenta; Shimizu, Takashi; Watarai, Masahisa

    2016-01-01

    Francisella tularensis, the causative agent of tularemia, is a highly virulent facultative intracellular pathogen found in a wide range of animals, including arthropods, and environments. This bacterium has been known for over 100 years, but the lifestyle of F. tularensis in natural reservoirs remains largely unknown. Thus, we established a novel natural host model for F. tularensis using the silkworm (Bombyx mori), which is an insect model for infection by pathogens. F. tularensis established a symbiosis with silkworms, and bacteria were observed in the hemolymph. After infection with F. tularensis, the induction of melanization and nodulation, which are immune responses to bacterial infection, were inhibited in silkworms. Pre-inoculation of silkworms with F. tularensis enhanced the expression of antimicrobial peptides and resistance to infection by pathogenic bacteria. These results suggest that silkworms acquire host resistance via their symbiosis with F. tularensis, which may have important fitness benefits in natural reservoirs. PMID:27507264

  11. Convergent losses of decay mechanisms and rapid turnover of symbiosis genes in mycorrhizal mutualists

    DOE PAGES

    Kohler, Annegret; Kuo, Alan; Nagy, Laszlo G.; Morin, Emmanuelle; Barry, Kerrie W.; Buscot, Francois; Canbäck, Björn; Choi, Cindy; Cichocki, Nicolas; Clum, Alicia; et al

    2015-02-23

    To elucidate the genetic bases of mycorrhizal lifestyle evolution, we sequenced new fungal genomes, including 13 ectomycorrhizal (ECM), orchid (ORM) and ericoid (ERM) species, and five saprotrophs, which we analyzed along with other fungal genomes. Ectomycorrhizal fungi have a reduced complement of genes encoding plant cell wall-degrading enzymes (PCWDEs), as compared to their ancestral wood decayers. Nevertheless, they have retained a unique array of PCWDEs, thus suggesting that they possess diverse abilities to decompose lignocellulose. Similar functional categories of nonorthologous genes are induced in symbiosis. Of induced genes, 7-38% are orphan genes, including genes that encode secreted effector-like proteins. Convergentmore » evolution of the mycorrhizal habit in fungi occurred via the repeated evolution of a 'symbiosis toolkit', with reduced numbers of PCWDEs and lineage-specific suites of mycorrhiza-induced genes.« less

  12. Convergent losses of decay mechanisms and rapid turnover of symbiosis genes in mycorrhizal mutualists

    SciTech Connect

    Kohler, Annegret; Kuo, Alan; Nagy, Laszlo G.; Morin, Emmanuelle; Barry, Kerrie W.; Buscot, Francois; Canbäck, Björn; Choi, Cindy; Cichocki, Nicolas; Clum, Alicia; Colpaert, Jan; Copeland, Alex; Costa, Mauricio D.; Doré, Jeanne; Floudas, Dimitrios; Gay, Gilles; Girlanda, Mariangela; Henrissat, Bernard; Herrmann, Sylvie; Hess, Jaqueline; Högberg, Nils; Johansson, Tomas; Khouja, Hassine-Radhouane; LaButti, Kurt; Lahrmann, Urs; Levasseur, Anthony; Lindquist, Erika A.; Lipzen, Anna; Marmeisse, Roland; Martino, Elena; Murat, Claude; Ngan, Chew Y.; Nehls, Uwe; Plett, Jonathan M.; Pringle, Anne; Ohm, Robin A.; Perotto, Silvia; Peter, Martina; Riley, Robert; Rineau, Francois; Ruytinx, Joske; Salamov, Asaf; Shah, Firoz; Sun, Hui; Tarkka, Mika; Tritt, Andrew; Veneault-Fourrey, Claire; Zuccaro, Alga; Tunlid, Anders; Grigoriev, Igor V.; Hibbett, David S.; Martin, Francis

    2015-02-23

    To elucidate the genetic bases of mycorrhizal lifestyle evolution, we sequenced new fungal genomes, including 13 ectomycorrhizal (ECM), orchid (ORM) and ericoid (ERM) species, and five saprotrophs, which we analyzed along with other fungal genomes. Ectomycorrhizal fungi have a reduced complement of genes encoding plant cell wall-degrading enzymes (PCWDEs), as compared to their ancestral wood decayers. Nevertheless, they have retained a unique array of PCWDEs, thus suggesting that they possess diverse abilities to decompose lignocellulose. Similar functional categories of nonorthologous genes are induced in symbiosis. Of induced genes, 7-38% are orphan genes, including genes that encode secreted effector-like proteins. Convergent evolution of the mycorrhizal habit in fungi occurred via the repeated evolution of a 'symbiosis toolkit', with reduced numbers of PCWDEs and lineage-specific suites of mycorrhiza-induced genes.

  13. Towards symbiosis in knowledge representation and natural language processing for structuring clinical practice guidelines.

    PubMed

    Weng, Chunhua; Payne, Philip R O; Velez, Mark; Johnson, Stephen B; Bakken, Suzanne

    2014-01-01

    The successful adoption by clinicians of evidence-based clinical practice guidelines (CPGs) contained in clinical information systems requires efficient translation of free-text guidelines into computable formats. Natural language processing (NLP) has the potential to improve the efficiency of such translation. However, it is laborious to develop NLP to structure free-text CPGs using existing formal knowledge representations (KR). In response to this challenge, this vision paper discusses the value and feasibility of supporting symbiosis in text-based knowledge acquisition (KA) and KR. We compare two ontologies: (1) an ontology manually created by domain experts for CPG eligibility criteria and (2) an upper-level ontology derived from a semantic pattern-based approach for automatic KA from CPG eligibility criteria text. Then we discuss the strengths and limitations of interweaving KA and NLP for KR purposes and important considerations for achieving the symbiosis of KR and NLP for structuring CPGs to achieve evidence-based clinical practice.

  14. [The defense and regulatory mechanisms during development of legume-Rhizobium symbiosis].

    PubMed

    Glian'ko, A K; Akimova, G P; Sokolova, M G; Makarova, L E; Vasil'eva, G G

    2007-01-01

    The roles of indolylacetic acid, the peroxidase system, catalase, active oxygen species, and phenolic compounds in the physiological and biochemical mechanisms involved in the autoregulation of nodulation in the developing legume-Rhizobium symbiosis were studied. It was inferred that the concentration of indolylacetic acid in the roots of inoculated plants, controlled by the enzymes of the peroxidase complex, is the signal permitting or limiting nodulation at the initial stages of symbiotic interaction. Presumably, the change in the level of active oxygen species is determined by an antioxidant activity of phenolic compounds. During the development of symbiosis, phytohormones, antioxidant enzymes, and active oxygen species may be involved in the regulation of infection via both a direct antibacterial action and regulation of functional activity of the host plant defense systems. PMID:17619575

  15. Neo-Symbiosis: The Next Stage in the Evolution of Human Information Interaction

    SciTech Connect

    Griffith, Douglas; Greitzer, Frank L.

    2007-01-01

    Abstract--The purpose of this paper is to re-address the vision of human-computer symbiosis as originally expressed by J.C.R. Licklider nearly a half-century ago. We describe this vision, place it in some historical context relating to the evolution of human factors research, and we observe that the field is now in the process of re-invigorating Licklider’s vision. We briefly assess the state of the technology within the context of contemporary theory and practice, and we describe what we regard as this emerging field of neo-symbiosis. We offer some initial thoughts on requirements to define functionality of neo-symbiotic systems and discuss research challenges associated with their development and evaluation.

  16. Transcriptomic Analysis of Sinorhizobium meliloti and Medicago truncatula Symbiosis Using Nitrogen Fixation-Deficient Nodules.

    PubMed

    Lang, Claus; Long, Sharon R

    2015-08-01

    The bacterium Sinorhizobium meliloti interacts symbiotically with legume plant hosts such as Medicago truncatula to form nitrogen-fixing root nodules. During symbiosis, plant and bacterial cells differentiate in a coordinated manner, resulting in specialized plant cells that contain nitrogen-fixing bacteroids. Both plant and bacterial genes are required at each developmental stage of symbiosis. We analyzed gene expression in nodules formed by wild-type bacteria on six plant mutants with defects in nitrogen fixation. We observed differential expression of 482 S. meliloti genes with functions in cell envelope homeostasis, cell division, stress response, energy metabolism, and nitrogen fixation. We simultaneously analyzed gene expression in M. truncatula and observed differential regulation of host processes that may trigger bacteroid differentiation and control bacterial infection. Our analyses of developmentally arrested plant mutants indicate that plants use distinct means to control bacterial infection during early and late symbiotic stages.

  17. New evidence for the symbiosis between Tuber aestivum and Picea abies.

    PubMed

    Stobbe, Ulrich; Stobbe, Annika; Sproll, Ludger; Tegel, Willy; Peter, Martina; Büntgen, Ulf; Egli, Simon

    2013-11-01

    The Burgundy truffle (Tuber aestivum Vittad.), an ectomycorrhizal fungus living in association with host plants, is one of the most exclusive delicacies. The symbiosis with deciduous oak, beech, and hazel dominates our concept of truffle ecophysiology, whereas potential conifer hosts have rarely been reported. Here, we present morphological and molecular evidence of a wildlife T. aestivum symbiosis with Norway spruce (Picea abies Karst.) and an independent greenhouse inoculation experiment, to confirm our field observation in southwest Germany. A total of 27 out of 50 P. abies seedlings developed T. aestivum ectomycorrhizae with a mean mycorrhization rate of 19.6 %. These findings not only suggest P. abies to be a productive host species under suitable biogeographic conditions but also emphasize the broad ecological amplitude and great symbiotic range of T. aestivum. While challenging common knowledge, this study demonstrates a significant expansion of the species' cultivation potential to the central European regions, where P. abies forests occur on calcareous soils.

  18. Symbiosis of Steel, Energy, and CO2 Evolution in Korea

    NASA Astrophysics Data System (ADS)

    Lee, Hyunjoung; Matsuura, Hiroyuki; Sohn, Il

    2016-09-01

    This study looks at the energy intensity of the steel industry and the greenhouse gas intensity involved with the production of steel. Using several sources of steel production data and the corresponding energy sources used provides a time-series analysis of the greenhouse gas (GHG) and energy intensity from 1990 to 2014. The impact of the steel economy with the gross domestic product (GDP) provides indirect importance of the general manufacturing sector within Korea and in particular the steel industry. Beyond 2008, the shift in excess materials production and significant increase in total imports have led to an imbalance in the Korean steel market and continue to inhibit the growth of the domestic steel market. The forecast of the GHG and energy intensity along with the steel production up to 2030 is provided using the auto regressive integrated moving average analysis.

  19. Oak Root Response to Ectomycorrhizal Symbiosis Establishment: RNA-Seq Derived Transcript Identification and Expression Profiling

    PubMed Central

    Lino-Neto, Teresa; Monteiro, Filipa; Figueiredo, Andreia; Sousa, Lisete; Pais, Maria Salomé; Tavares, Rui; Paulo, Octávio S.

    2014-01-01

    Ectomycorrhizal symbiosis is essential for the life and health of trees in temperate and boreal forests where it plays a major role in nutrient cycling and in functioning of the forest ecosystem. Trees with ectomycorrhizal root tips are more tolerant to environmental stresses, such as drought, and biotic stresses such as root pathogens. Detailed information on these molecular processes is essential for the understanding of symbiotic tissue development in order to optimize the benefits of this natural phenomenon. Next generation sequencing tools allow the analysis of non model ectomycorrhizal plant-fungal interactions that can contribute to find the “symbiosis toolkits” and better define the role of each partner in the mutualistic interaction. By using 454 pyrosequencing we compared ectomycorrhizal cork oak roots with non-symbiotic roots. From the two cDNA libraries sequenced, over 2 million reads were obtained that generated 19552 cork oak root unique transcripts. A total of 2238 transcripts were found to be differentially expressed when ECM roots were compared with non-symbiotic roots. Identification of up- and down-regulated gens in ectomycorrhizal roots lead to a number of insights into the molecular mechanisms governing this important symbiosis. In cork oak roots, ectomycorrhizal colonization resulted in extensive cell wall remodelling, activation of the secretory pathway, alterations in flavonoid biosynthesis, and expression of genes involved in the recognition of fungal effectors. In addition, we identified genes with putative roles in symbiotic processes such as nutrient exchange with the fungal partner, lateral root formation or root hair decay. These findings provide a global overview of the transcriptome of an ectomycorrhizal host root, and constitute a foundation for future studies on the molecular events controlling this important symbiosis. PMID:24859293

  20. Assess suitability of hydroaeroponic culture to establish tripartite symbiosis between different AMF species, beans, and rhizobia

    PubMed Central

    Tajini, Fatma; Suriyakup, Porntip; Vailhe, Hélène; Jansa, Jan; Drevon, Jean-Jacques

    2009-01-01

    Background Like other species of the Phaseoleae tribe, common bean (Phaseolus vulgaris L.) has the potential to establish symbiosis with rhizobia and to fix the atmospheric dinitrogen (N2) for its N nutrition. Common bean has also the potential to establish symbiosis with arbuscular mycorrhizal fungi (AMF) that improves the uptake of low mobile nutrients such as phosphorus, from the soil. Both rhizobial and mycorrhizal symbioses can act synergistically in benefits on plant. Results The tripartite symbiosis of common bean with rhizobia and arbuscular mycorrhizal fungi (AMF) was assessed in hydroaeroponic culture with common bean (Phaseolus vulgaris L.), by comparing the effects of three fungi spp. on growth, nodulation and mycorrhization of the roots under sufficient versus deficient P supplies, after transfer from initial sand culture. Although Glomus intraradices Schenck & Smith colonized intensely the roots of common bean in both sand and hydroaeroponic cultures, Gigaspora rosea Nicolson & Schenck only established well under sand culture conditions, and no root-colonization was found with Acaulospora mellea Spain & Schenck under either culture conditions. Interestingly, mycorrhization by Glomus was also obtained by contact with mycorrhized Stylosanthes guianensis (Aubl.) sw in sand culture under deficient P before transfer into hydroaeroponic culture. The effect of bean genotype on both rhizobial and mycorrhizal symbioses with Glomus was subsequently assessed with the common bean recombinant inbreed line 7, 28, 83, 115 and 147, and the cultivar Flamingo. Significant differences among colonization and nodulation of the roots and growth among genotypes were found. Conclusion The hydroaeroponic culture is a valuable tool for further scrutinizing the physiological interactions and nutrient partitioning within the tripartite symbiosis. PMID:19534785

  1. The role of fungal symbiosis in the adaptation of plants to high stress environments

    USGS Publications Warehouse

    Rodriguez, Russell J.; Redman, Regina S.; Henson, Joan M.

    2004-01-01

    All plants studied in natural ecosystemsare symbiotic with fungi that either resideentirely (endophytes) or partially(mycorrhizae) within plants. Thesesymbioses appear to adapt to biotic andabiotic stresses and may be responsible forthe survival of both plant hosts and fungalsymbionts in high stress habitats. Here wedescribe the role of symbiotic fungi inplant stress tolerance and present astrategy based on adaptive symbiosis topotentially mitigate the impacts of globalchange on plant communities.

  2. Sinorhizobium meliloti requires a cobalamin-dependent ribonucleotide reductase for symbiosis with its plant host.

    PubMed

    Taga, Michiko E; Walker, Graham C

    2010-12-01

    Vitamin B(12) (cobalamin) is a critical cofactor for animals and protists, yet its biosynthesis is limited to prokaryotes. We previously showed that the symbiotic nitrogen-fixing alphaproteobacterium Sinorhizobium meliloti requires cobalamin to establish a symbiotic relationship with its plant host, Medicago sativa (alfalfa). Here, the specific requirement for cobalamin in the S. meliloti-alfalfa symbiosis was investigated. Of the three known cobalamin-dependent enzymes in S. meliloti, the methylmalonyl CoA mutase (BhbA) does not affect symbiosis, whereas disruption of the metH gene encoding the cobalamin-dependent methionine synthase causes a significant defect in symbiosis. Expression of the cobalamin-independent methionine synthase MetE alleviates this symbiotic defect, indicating that the requirement for methionine synthesis does not reflect a need for the cobalamin-dependent enzyme. To investigate the function of the cobalamin-dependent ribonucleotide reductase (RNR) encoded by nrdJ, S. meliloti was engineered to express an Escherichia coli cobalamin-independent (class Ia) RNR instead of nrdJ. This strain is severely defective in symbiosis. Electron micrographs show that these cells can penetrate alfalfa nodules but are unable to differentiate into nitrogen-fixing bacteroids and, instead, are lysed in the plant cytoplasm. Flow cytometry analysis indicates that these bacteria are largely unable to undergo endoreduplication. These phenotypes may be due either to the inactivation of the class Ia RNR by reactive oxygen species, inadequate oxygen availability in the nodule, or both. These results show that the critical role of the cobalamin-dependent RNR for survival of S. meliloti in its plant host can account for the considerable resources that S. meliloti dedicates to cobalamin biosynthesis.

  3. [Signal exchange between plants and Arbuscular Mycorrhizae fungi during the early stage of symbiosis - A review].

    PubMed

    Duan, Qianqian; Yang, Xiaohong; Huang, Xianzhi

    2015-07-01

    Much is known about Arbuscular Mycorrhizae (AM), an important component of the ecosystem, whereas little is known about the signal exchange that allows mutual recognition and reprograming for the anticipated physical interaction. This review addresses the latest advances of signal exchange between plants and AM, including signal substances and their function, related genes and regulation function in the early stage of plant-fungal symbiosis.

  4. Oak root response to ectomycorrhizal symbiosis establishment: RNA-Seq derived transcript identification and expression profiling.

    PubMed

    Sebastiana, Mónica; Vieira, Bruno; Lino-Neto, Teresa; Monteiro, Filipa; Figueiredo, Andreia; Sousa, Lisete; Pais, Maria Salomé; Tavares, Rui; Paulo, Octávio S

    2014-01-01

    Ectomycorrhizal symbiosis is essential for the life and health of trees in temperate and boreal forests where it plays a major role in nutrient cycling and in functioning of the forest ecosystem. Trees with ectomycorrhizal root tips are more tolerant to environmental stresses, such as drought, and biotic stresses such as root pathogens. Detailed information on these molecular processes is essential for the understanding of symbiotic tissue development in order to optimize the benefits of this natural phenomenon. Next generation sequencing tools allow the analysis of non model ectomycorrhizal plant-fungal interactions that can contribute to find the "symbiosis toolkits" and better define the role of each partner in the mutualistic interaction. By using 454 pyrosequencing we compared ectomycorrhizal cork oak roots with non-symbiotic roots. From the two cDNA libraries sequenced, over 2 million reads were obtained that generated 19,552 cork oak root unique transcripts. A total of 2238 transcripts were found to be differentially expressed when ECM roots were compared with non-symbiotic roots. Identification of up- and down-regulated gens in ectomycorrhizal roots lead to a number of insights into the molecular mechanisms governing this important symbiosis. In cork oak roots, ectomycorrhizal colonization resulted in extensive cell wall remodelling, activation of the secretory pathway, alterations in flavonoid biosynthesis, and expression of genes involved in the recognition of fungal effectors. In addition, we identified genes with putative roles in symbiotic processes such as nutrient exchange with the fungal partner, lateral root formation or root hair decay. These findings provide a global overview of the transcriptome of an ectomycorrhizal host root, and constitute a foundation for future studies on the molecular events controlling this important symbiosis.

  5. Something old, something new: auxin and strigolactone interact in the ancient mycorrhizal symbiosis.

    PubMed

    Foo, Eloise

    2013-04-01

    Arbuscular mycorrhizal symbiosis, formed between more than 80% of land plants and fungi from the phylum Glomeromycota, is an ancient association that is believed to have evolved as plants moved onto land more than 400 mya. Similarly ancient, the plant hormones auxin and strigolactone are thought to have been present in the plant lineage since before the divergence of the bryophytes in the case of auxin and before the colonisation of land in the case of strigolactones. The discovery of auxin in the 1930s predates the discovery of strigolactones as a plant hormone in 2008 by over 70 y. Recent studies in pea suggest that these two signals may interact to regulate mycorrhizal symbiosis. Furthermore, the first quantitative studies are presented that show that low auxin content of the root is correlated with low strigolactone production, an interaction that has implications for how these plant hormones regulate several developmental programs including shoot branching, secondary growth and root development. With recent advances in our understanding of auxin and strigolactone biosynthesis, together with the discovery of the fungal signals that activate the plant host, the stage is set for real breakthroughs in our understanding of the interactions between plant and fungal signals in mycorrhizal symbiosis.

  6. Effect of two AMF life strategies on the tripartite symbiosis with Bradyrhizobium japonicum and soybean.

    PubMed

    Antunes, Pedro M; Deaville, Deanna; Goss, Michael J

    2006-05-01

    This study is the first in assessing the effect of soil disturbance on the contribution of arbuscular mycorrhizal fungi (AMF) with different life-history strategies to the tripartite symbiosis with soybeans and Bradyrhizobium japonicum (Kirchner) Jordan. We hypothesized that Gigaspora margarita Becker and Hall would be more affected by soil disturbance than Glomus clarum Nicol. and Schenck, and consequently, the tripartite symbiosis would develop more rapidly and lead to greater N(2) fixation in the presence of the latter. Soil pasteurization allowed the establishment of treatments with individual AMF species and soil disturbance enabled the development of contrasting root colonization potentials. In contrast, the colonization potential of B. japonicum was kept the same in all treatments. Soil disturbance significantly reduced root colonization by both AMF, with Gi. margarita being considerably more affected than G. clarum. Furthermore, the tripartite symbiosis progressed faster with G. clarum, and at 10 days after plant emergence, there was 30% more nodules when G. clarum was present compared to that when the bacterial symbiont alone was present. At flowering, the absence of soil disturbance stimulated N(2) fixation by 17% in mycorrhizal plants. However, this response was similar for both AMF.

  7. Burkholderia bacteria infectiously induce the proto-farming symbiosis of Dictyostelium amoebae and food bacteria.

    PubMed

    DiSalvo, Susanne; Haselkorn, Tamara S; Bashir, Usman; Jimenez, Daniela; Brock, Debra A; Queller, David C; Strassmann, Joan E

    2015-09-01

    Symbiotic associations can allow an organism to acquire novel traits by accessing the genetic repertoire of its partner. In the Dictyostelium discoideum farming symbiosis, certain amoebas (termed "farmers") stably associate with bacterial partners. Farmers can suffer a reproductive cost but also gain beneficial capabilities, such as carriage of bacterial food (proto-farming) and defense against competitors. Farming status previously has been attributed to amoeba genotype, but the role of bacterial partners in its induction has not been examined. Here, we explore the role of bacterial associates in the initiation, maintenance, and phenotypic effects of the farming symbiosis. We demonstrate that two clades of farmer-associated Burkholderia isolates colonize D. discoideum nonfarmers and infectiously endow them with farmer-like characteristics, indicating that Burkholderia symbionts are a major driver of the farming phenomenon. Under food-rich conditions, Burkholderia-colonized amoebas produce fewer spores than uncolonized counterparts, with the severity of this reduction being dependent on the Burkholderia colonizer. However, the induction of food carriage by Burkholderia colonization may be considered a conditionally adaptive trait because it can confer an advantage to the amoeba host when grown in food-limiting conditions. We observed Burkholderia inside and outside colonized D. discoideum spores after fruiting body formation; this observation, together with the ability of Burkholderia to colonize new amoebas, suggests a mixed mode of symbiont transmission. These results change our understanding of the D. discoideum farming symbiosis by establishing that the bacterial partner, Burkholderia, is an important causative agent of the farming phenomenon.

  8. Symbiont-driven sulfur crystal formation in a thiotrophic symbiosis from deep-sea hydrocarbon seeps

    PubMed Central

    Eichinger, Irmgard; Schmitz-Esser, Stephan; Schmid, Markus; Fisher, Charles R; Bright, Monika

    2014-01-01

    The siboglinid tubeworm Sclerolinum contortum symbiosis inhabits sulfidic sediments at deep-sea hydrocarbon seeps in the Gulf of Mexico. A single symbiont phylotype in the symbiont-housing organ is inferred from phylogenetic analyses of the 16S ribosomal ribonucleic acid (16S rRNA) gene and fluorescent in situ hybridization. The phylotype we studied here, and a previous study from an arctic hydrocarbon seep population, reveal identical 16S rRNA symbiont gene sequences. While sulfide is apparently the energy source for the symbionts (and ultimately the gutless host), both partners also have to cope with its toxicity. This study demonstrates abundant large sulfur crystals restricted to the trophosome area. Based on Raman microspectroscopy and energy dispersive X-ray analysis, these crystals have the same S8 sulfur configuration as the recently described small sulfur vesicles formed in the symbionts. The crystals reside adjacent to the symbionts in the trophosome. This suggests that their formation is either extra- or intracellular in symbionts. We propose that formation of these crystals provides both energy-storage compounds for the symbionts and serves the symbiosis by removing excess toxic sulfide from host tissues. This symbiont-mediated sulfide detoxification may have been crucial for the establishment of thiotrophic symbiosis and continues to remain an important function of the symbionts. PMID:24992535

  9. Use of carbon monoxide and hydrogen by a bacteria–animal symbiosis from seagrass sediments

    PubMed Central

    Holler, Thomas; Lavik, Gaute; Harder, Jens; Lott, Christian; Littmann, Sten; Kuypers, Marcel M. M.; Dubilier, Nicole

    2015-01-01

    Summary The gutless marine worm O lavius algarvensis lives in symbiosis with chemosynthetic bacteria that provide nutrition by fixing carbon dioxide (CO 2) into biomass using reduced sulfur compounds as energy sources. A recent metaproteomic analysis of the O . algarvensis symbiosis indicated that carbon monoxide (CO) and hydrogen (H 2) might also be used as energy sources. We provide direct evidence that the O . algarvensis symbiosis consumes CO and H 2. Single cell imaging using nanoscale secondary ion mass spectrometry revealed that one of the symbionts, the γ3‐symbiont, uses the energy from CO oxidation to fix CO 2. Pore water analysis revealed considerable in‐situ concentrations of CO and H 2 in the O . algarvensis environment, Mediterranean seagrass sediments. Pore water H 2 concentrations (89–2147 nM) were up to two orders of magnitude higher than in seawater, and up to 36‐fold higher than previously known from shallow‐water marine sediments. Pore water CO concentrations (17–51 nM) were twice as high as in the overlying seawater (no literature data from other shallow‐water sediments are available for comparison). Ex‐situ incubation experiments showed that dead seagrass rhizomes produced large amounts of CO. CO production from decaying plant material could thus be a significant energy source for microbial primary production in seagrass sediments. PMID:26013766

  10. Large-Scale Label-Free Quantitative Proteomics of the Pea aphid-Buchnera Symbiosis*

    PubMed Central

    Poliakov, Anton; Russell, Calum W.; Ponnala, Lalit; Hoops, Harold J.; Sun, Qi; Douglas, Angela E.; van Wijk, Klaas J.

    2011-01-01

    Many insects are nutritionally dependent on symbiotic microorganisms that have tiny genomes and are housed in specialized host cells called bacteriocytes. The obligate symbiosis between the pea aphid Acyrthosiphon pisum and the γ-proteobacterium Buchnera aphidicola (only 584 predicted proteins) is particularly amenable for molecular analysis because the genomes of both partners have been sequenced. To better define the symbiotic relationship between this aphid and Buchnera, we used large-scale, high accuracy tandem mass spectrometry (nanoLC-LTQ-Orbtrap) to identify aphid and Buchnera proteins in the whole aphid body, purified bacteriocytes, isolated Buchnera cells and the residual bacteriocyte fraction. More than 1900 aphid and 400 Buchnera proteins were identified. All enzymes in amino acid metabolism annotated in the Buchnera genome were detected, reflecting the high (68%) coverage of the proteome and supporting the core function of Buchnera in the aphid symbiosis. Transporters mediating the transport of predicted metabolites were present in the bacteriocyte. Label-free spectral counting combined with hierarchical clustering, allowed to define the quantitative distribution of a subset of these proteins across both symbiotic partners, yielding no evidence for the selective transfer of protein among the partners in either direction. This is the first quantitative proteome analysis of bacteriocyte symbiosis, providing a wealth of information about molecular function of both the host cell and bacterial symbiont. PMID:21421797

  11. Something old, something new: auxin and strigolactone interact in the ancient mycorrhizal symbiosis.

    PubMed

    Foo, Eloise

    2013-04-01

    Arbuscular mycorrhizal symbiosis, formed between more than 80% of land plants and fungi from the phylum Glomeromycota, is an ancient association that is believed to have evolved as plants moved onto land more than 400 mya. Similarly ancient, the plant hormones auxin and strigolactone are thought to have been present in the plant lineage since before the divergence of the bryophytes in the case of auxin and before the colonisation of land in the case of strigolactones. The discovery of auxin in the 1930s predates the discovery of strigolactones as a plant hormone in 2008 by over 70 y. Recent studies in pea suggest that these two signals may interact to regulate mycorrhizal symbiosis. Furthermore, the first quantitative studies are presented that show that low auxin content of the root is correlated with low strigolactone production, an interaction that has implications for how these plant hormones regulate several developmental programs including shoot branching, secondary growth and root development. With recent advances in our understanding of auxin and strigolactone biosynthesis, together with the discovery of the fungal signals that activate the plant host, the stage is set for real breakthroughs in our understanding of the interactions between plant and fungal signals in mycorrhizal symbiosis. PMID:23333973

  12. Multi-gene analysis of Symbiodinium dinoflagellates: a perspective on rarity, symbiosis, and evolution

    PubMed Central

    Putnam, Hollie M.; Gates, Ruth D.

    2014-01-01

    Symbiodinium, a large group of dinoflagellates, live in symbiosis with marine protists, invertebrate metazoans, and free-living in the environment. Symbiodinium are functionally variable and play critical energetic roles in symbiosis. Our knowledge of Symbiodinium has been historically constrained by the limited number of molecular markers available to study evolution in the genus. Here we compare six functional genes, representing three cellular compartments, in the nine known Symbiodinium lineages. Despite striking similarities among the single gene phylogenies from distinct organelles, none were evolutionarily identical. A fully concatenated reconstruction, however, yielded a well-resolved topology identical to the current benchmark nr28S gene. Evolutionary rates differed among cellular compartments and clades, a pattern largely driven by higher rates of evolution in the chloroplast genes of Symbiodinium clades D2 and I. The rapid rates of evolution observed amongst these relatively uncommon Symbiodinium lineages in the functionally critical chloroplast may translate into potential innovation for the symbiosis. The multi-gene analysis highlights the potential power of assessing genome-wide evolutionary patterns using recent advances in sequencing technology and emphasizes the importance of integrating ecological data with more comprehensive sampling of free-living and symbiotic Symbiodinium in assessing the evolutionary adaptation of this enigmatic dinoflagellate. PMID:24883254

  13. Development and Symbiosis Establishment in the Cnidarian Endosymbiosis Model Aiptasia sp.

    PubMed Central

    Bucher, Madeline; Wolfowicz, Iliona; Voss, Philipp A.; Hambleton, Elizabeth A.; Guse, Annika

    2016-01-01

    Symbiosis between photosynthetic algae and heterotrophic organisms is widespread. One prominent example of high ecological relevance is the endosymbiosis between dinoflagellate algae of the genus Symbiodinium and reef-building corals, which typically acquire symbionts anew each generation during larval stages. The tropical sea anemone Aiptasia sp. is a laboratory model system for this endosymbiosis and, similar to corals, produces non-symbiotic larvae that establish symbiosis by phagocytosing Symbiodinium from the environment into the endoderm. Here we generate the first overview of Aiptasia embryogenesis and larval development and establish in situ hybridization to analyze expression patterns of key early developmental regulators. Next, we quantify morphological changes in developing larvae and find a substantial enlargement of the gastric cavity over time. Symbiont acquisition starts soon after mouth formation and symbionts occupy a major portion of the host cell in which they reside. During the first 14 days of development, infection efficiency remains constant while in contrast, localization of phagocytosed symbionts changes, indicating that the occurrence of functional phagocytosing cells may be developmentally regulated. Taken together, here we provide the essential framework to further develop Aiptasia as a model system for the analysis of symbiosis establishment in cnidarian larvae at the molecular level. PMID:26804034

  14. Use of carbon monoxide and hydrogen by a bacteria-animal symbiosis from seagrass sediments.

    PubMed

    Kleiner, Manuel; Wentrup, Cecilia; Holler, Thomas; Lavik, Gaute; Harder, Jens; Lott, Christian; Littmann, Sten; Kuypers, Marcel M M; Dubilier, Nicole

    2015-12-01

    The gutless marine worm Olavius algarvensis lives in symbiosis with chemosynthetic bacteria that provide nutrition by fixing carbon dioxide (CO2 ) into biomass using reduced sulfur compounds as energy sources. A recent metaproteomic analysis of the O. algarvensis symbiosis indicated that carbon monoxide (CO) and hydrogen (H2 ) might also be used as energy sources. We provide direct evidence that the O. algarvensis symbiosis consumes CO and H2 . Single cell imaging using nanoscale secondary ion mass spectrometry revealed that one of the symbionts, the γ3-symbiont, uses the energy from CO oxidation to fix CO2 . Pore water analysis revealed considerable in-situ concentrations of CO and H2 in the O. algarvensis environment, Mediterranean seagrass sediments. Pore water H2 concentrations (89-2147 nM) were up to two orders of magnitude higher than in seawater, and up to 36-fold higher than previously known from shallow-water marine sediments. Pore water CO concentrations (17-51 nM) were twice as high as in the overlying seawater (no literature data from other shallow-water sediments are available for comparison). Ex-situ incubation experiments showed that dead seagrass rhizomes produced large amounts of CO. CO production from decaying plant material could thus be a significant energy source for microbial primary production in seagrass sediments.

  15. Use of carbon monoxide and hydrogen by a bacteria-animal symbiosis from seagrass sediments.

    PubMed

    Kleiner, Manuel; Wentrup, Cecilia; Holler, Thomas; Lavik, Gaute; Harder, Jens; Lott, Christian; Littmann, Sten; Kuypers, Marcel M M; Dubilier, Nicole

    2015-12-01

    The gutless marine worm Olavius algarvensis lives in symbiosis with chemosynthetic bacteria that provide nutrition by fixing carbon dioxide (CO2 ) into biomass using reduced sulfur compounds as energy sources. A recent metaproteomic analysis of the O. algarvensis symbiosis indicated that carbon monoxide (CO) and hydrogen (H2 ) might also be used as energy sources. We provide direct evidence that the O. algarvensis symbiosis consumes CO and H2 . Single cell imaging using nanoscale secondary ion mass spectrometry revealed that one of the symbionts, the γ3-symbiont, uses the energy from CO oxidation to fix CO2 . Pore water analysis revealed considerable in-situ concentrations of CO and H2 in the O. algarvensis environment, Mediterranean seagrass sediments. Pore water H2 concentrations (89-2147 nM) were up to two orders of magnitude higher than in seawater, and up to 36-fold higher than previously known from shallow-water marine sediments. Pore water CO concentrations (17-51 nM) were twice as high as in the overlying seawater (no literature data from other shallow-water sediments are available for comparison). Ex-situ incubation experiments showed that dead seagrass rhizomes produced large amounts of CO. CO production from decaying plant material could thus be a significant energy source for microbial primary production in seagrass sediments. PMID:26013766

  16. Multi-gene analysis of Symbiodinium dinoflagellates: a perspective on rarity, symbiosis, and evolution.

    PubMed

    Pochon, Xavier; Putnam, Hollie M; Gates, Ruth D

    2014-01-01

    Symbiodinium, a large group of dinoflagellates, live in symbiosis with marine protists, invertebrate metazoans, and free-living in the environment. Symbiodinium are functionally variable and play critical energetic roles in symbiosis. Our knowledge of Symbiodinium has been historically constrained by the limited number of molecular markers available to study evolution in the genus. Here we compare six functional genes, representing three cellular compartments, in the nine known Symbiodinium lineages. Despite striking similarities among the single gene phylogenies from distinct organelles, none were evolutionarily identical. A fully concatenated reconstruction, however, yielded a well-resolved topology identical to the current benchmark nr28S gene. Evolutionary rates differed among cellular compartments and clades, a pattern largely driven by higher rates of evolution in the chloroplast genes of Symbiodinium clades D2 and I. The rapid rates of evolution observed amongst these relatively uncommon Symbiodinium lineages in the functionally critical chloroplast may translate into potential innovation for the symbiosis. The multi-gene analysis highlights the potential power of assessing genome-wide evolutionary patterns using recent advances in sequencing technology and emphasizes the importance of integrating ecological data with more comprehensive sampling of free-living and symbiotic Symbiodinium in assessing the evolutionary adaptation of this enigmatic dinoflagellate.

  17. A symbiosis-dedicated SYNTAXIN OF PLANTS 13II isoform controls the formation of a stable host-microbe interface in symbiosis.

    PubMed

    Huisman, Rik; Hontelez, Jan; Mysore, Kirankumar S; Wen, Jiangqi; Bisseling, Ton; Limpens, Erik

    2016-09-01

    Arbuscular mycorrhizal (AM) fungi and rhizobium bacteria are accommodated in specialized membrane compartments that form a host-microbe interface. To better understand how these interfaces are made, we studied the regulation of exocytosis during interface formation. We used a phylogenetic approach to identify target soluble N-ethylmaleimide-sensitive factor-attachment protein receptors (t-SNAREs) that are dedicated to symbiosis and used cell-specific expression analysis together with protein localization to identify t-SNAREs that are present on the host-microbe interface in Medicago truncatula. We investigated the role of these t-SNAREs during the formation of a host-microbe interface. We showed that multiple syntaxins are present on the peri-arbuscular membrane. From these, we identified SYNTAXIN OF PLANTS 13II (SYP13II) as a t-SNARE that is essential for the formation of a stable symbiotic interface in both AM and rhizobium symbiosis. In most dicot plants, the SYP13II transcript is alternatively spliced, resulting in two isoforms, SYP13IIα and SYP13IIβ. These splice-forms differentially mark functional and degrading arbuscule branches. Our results show that vesicle traffic to the symbiotic interface is specialized and required for its maintenance. Alternative splicing of SYP13II allows plants to replace a t-SNARE involved in traffic to the plasma membrane with a t-SNARE that is more stringent in its localization to functional arbuscules. PMID:27110912

  18. A symbiosis-dedicated SYNTAXIN OF PLANTS 13II isoform controls the formation of a stable host-microbe interface in symbiosis.

    PubMed

    Huisman, Rik; Hontelez, Jan; Mysore, Kirankumar S; Wen, Jiangqi; Bisseling, Ton; Limpens, Erik

    2016-09-01

    Arbuscular mycorrhizal (AM) fungi and rhizobium bacteria are accommodated in specialized membrane compartments that form a host-microbe interface. To better understand how these interfaces are made, we studied the regulation of exocytosis during interface formation. We used a phylogenetic approach to identify target soluble N-ethylmaleimide-sensitive factor-attachment protein receptors (t-SNAREs) that are dedicated to symbiosis and used cell-specific expression analysis together with protein localization to identify t-SNAREs that are present on the host-microbe interface in Medicago truncatula. We investigated the role of these t-SNAREs during the formation of a host-microbe interface. We showed that multiple syntaxins are present on the peri-arbuscular membrane. From these, we identified SYNTAXIN OF PLANTS 13II (SYP13II) as a t-SNARE that is essential for the formation of a stable symbiotic interface in both AM and rhizobium symbiosis. In most dicot plants, the SYP13II transcript is alternatively spliced, resulting in two isoforms, SYP13IIα and SYP13IIβ. These splice-forms differentially mark functional and degrading arbuscule branches. Our results show that vesicle traffic to the symbiotic interface is specialized and required for its maintenance. Alternative splicing of SYP13II allows plants to replace a t-SNARE involved in traffic to the plasma membrane with a t-SNARE that is more stringent in its localization to functional arbuscules.

  19. Photovoltaics industry profile

    NASA Astrophysics Data System (ADS)

    1980-10-01

    A description of the status of the U.S. photovoltaics industry is given. Principal end user industries are identified, domestic and foreign market trends are discussed, and industry organized and U.S. government organized trade promotion events are listed. Trade associations and trade journals are listed, and a photovoltaic product manufacturers list is included.

  20. Framing Service, Benefit, and Credibility Through Images and Texts: A Content Analysis of Online Promotional Messages of Korean Medical Tourism Industry.

    PubMed

    Jun, Jungmi

    2016-07-01

    This study examines how the Korean medical tourism industry frames its service, benefit, and credibility issues through texts and images of online brochures. The results of content analysis suggest that the Korean medical tourism industry attempts to frame their medical/health services as "excellence in surgeries and cancer care" and "advanced health technology and facilities." However, the use of cost-saving appeals was limited, which can be seen as a strategy to avoid consumers' association of lower cost with lower quality services, and to stress safety and credibility. PMID:26644259

  1. Framing Service, Benefit, and Credibility Through Images and Texts: A Content Analysis of Online Promotional Messages of Korean Medical Tourism Industry.

    PubMed

    Jun, Jungmi

    2016-07-01

    This study examines how the Korean medical tourism industry frames its service, benefit, and credibility issues through texts and images of online brochures. The results of content analysis suggest that the Korean medical tourism industry attempts to frame their medical/health services as "excellence in surgeries and cancer care" and "advanced health technology and facilities." However, the use of cost-saving appeals was limited, which can be seen as a strategy to avoid consumers' association of lower cost with lower quality services, and to stress safety and credibility.

  2. First Description of Sulphur-Oxidizing Bacterial Symbiosis in a Cnidarian (Medusozoa) Living in Sulphidic Shallow-Water Environments

    PubMed Central

    Abouna, Sylvie; Gonzalez-Rizzo, Silvina; Grimonprez, Adrien; Gros, Olivier

    2015-01-01

    Background Since the discovery of thioautotrophic bacterial symbiosis in the giant tubeworm Riftia pachyptila, there has been great impetus to investigate such partnerships in other invertebrates. In this study, we present the occurrence of a sulphur-oxidizing symbiosis in a metazoan belonging to the phylum Cnidaria in which this event has never been described previously. Methodology/Principal Findings Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) observations and Energy-dispersive X-ray spectroscopy (EDXs) analysis, were employed to unveil the presence of prokaryotes population bearing elemental sulphur granules, growing on the body surface of the metazoan. Phylogenetic assessments were also undertaken to identify this invertebrate and microorganisms in thiotrophic symbiosis. Our results showed the occurrence of a thiotrophic symbiosis in a cnidarian identified as Cladonema sp. Conclusions/Significance This is the first report describing the occurrence of a sulphur-oxidizing symbiosis in a cnidarian. Furthermore, of the two adult morphologies, the polyp and medusa, this mutualistic association was found restricted to the polyp form of Cladonema sp. PMID:26011278

  3. Structural basis for regulation of rhizobial nodulation and symbiosis gene expression by the regulatory protein NolR

    PubMed Central

    Lee, Soon Goo; Krishnan, Hari B.; Jez, Joseph M.

    2014-01-01

    The symbiosis between rhizobial microbes and host plants involves the coordinated expression of multiple genes, which leads to nodule formation and nitrogen fixation. As part of the transcriptional machinery for nodulation and symbiosis across a range of Rhizobium, NolR serves as a global regulatory protein. Here, we present the X-ray crystal structures of NolR in the unliganded form and complexed with two different 22-base pair (bp) double-stranded operator sequences (oligos AT and AA). Structural and biochemical analysis of NolR reveals protein–DNA interactions with an asymmetric operator site and defines a mechanism for conformational switching of a key residue (Gln56) to accommodate variation in target DNA sequences from diverse rhizobial genes for nodulation and symbiosis. This conformational switching alters the energetic contributions to DNA binding without changes in affinity for the target sequence. Two possible models for the role of NolR in the regulation of different nodulation and symbiosis genes are proposed. To our knowledge, these studies provide the first structural insight on the regulation of genes involved in the agriculturally and ecologically important symbiosis of microbes and plants that leads to nodule formation and nitrogen fixation. PMID:24733893

  4. Structural basis for regulation of rhizobial nodulation and symbiosis gene expression by the regulatory protein NolR.

    PubMed

    Lee, Soon Goo; Krishnan, Hari B; Jez, Joseph M

    2014-04-29

    The symbiosis between rhizobial microbes and host plants involves the coordinated expression of multiple genes, which leads to nodule formation and nitrogen fixation. As part of the transcriptional machinery for nodulation and symbiosis across a range of Rhizobium, NolR serves as a global regulatory protein. Here, we present the X-ray crystal structures of NolR in the unliganded form and complexed with two different 22-base pair (bp) double-stranded operator sequences (oligos AT and AA). Structural and biochemical analysis of NolR reveals protein-DNA interactions with an asymmetric operator site and defines a mechanism for conformational switching of a key residue (Gln56) to accommodate variation in target DNA sequences from diverse rhizobial genes for nodulation and symbiosis. This conformational switching alters the energetic contributions to DNA binding without changes in affinity for the target sequence. Two possible models for the role of NolR in the regulation of different nodulation and symbiosis genes are proposed. To our knowledge, these studies provide the first structural insight on the regulation of genes involved in the agriculturally and ecologically important symbiosis of microbes and plants that leads to nodule formation and nitrogen fixation.

  5. Compartment-specific activation of PPARγ governs breast cancer tumor growth, via metabolic reprogramming and symbiosis.

    PubMed

    Avena, Paola; Anselmo, Wanda; Whitaker-Menezes, Diana; Wang, Chenguang; Pestell, Richard G; Lamb, Rebecca S; Hulit, James; Casaburi, Ivan; Andò, Sebastiano; Martinez-Outschoorn, Ubaldo E; Lisanti, Michael P; Sotgia, Federica

    2013-05-01

    The role of PPARγ in cancer therapy is controversial, with studies showing either pro-tumorigenic or antineoplastic effects. This debate is very clinically relevant, because PPARγ agonists are used as antidiabetic drugs. Here, we evaluated if the effects of PPARγ on tumorigenesis are determined by the cell type in which PPARγ is activated. Second, we examined if the metabolic changes induced by PPARγ, such as glycolysis and autophagy, play any role in the tumorigenic process. To this end, PPARγ was overexpressed in breast cancer cells or in stromal cells. PPARγ-overexpressing cells were examined with respect to (1) their tumorigenic potential, using xenograft models, and (2) regarding their metabolic features. In xenograft models, we show that when PPARγ is activated in cancer cells, tumor growth is inhibited by 40%. However, when PPARγ is activated in stromal cells, the growth of co-injected breast cancer cells is enhanced by 60%. Thus, the effect(s) of PPARγ on tumorigenesis are dependent on the cell compartment in which PPARγ is activated. Mechanistically, stromal cells with activated PPARγ display metabolic features of cancer-associated fibroblasts, with increased autophagy, glycolysis and senescence. Indeed, fibroblasts overexpressing PPARγ show increased expression of autophagic markers, increased numbers of acidic autophagic vacuoles, increased production of L-lactate, cell hypertrophy and mitochondrial dysfunction. In addition, PPARγ fibroblasts show increased expression of CDKs (p16/p21) and β-galactosidase, which are markers of cell cycle arrest and senescence. Finally, PPARγ induces the activation of the two major transcription factors that promote autophagy and glycolysis, i.e., HIF-1α and NFκB, in stromal cells. Thus, PPARγ activation in stromal cells results in the formation of a catabolic pro-inflammatory microenvironment that metabolically supports cancer growth. Interestingly, the tumor inhibition observed when PPARγ is

  6. 7 CFR 1220.112 - Industry information.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SOYBEAN PROMOTION, RESEARCH, AND CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.112 Industry information. The... markets, new marketing strategies, or increased efficiency for the soybean industry, and activities...

  7. Functional analysis of duplicated Symbiosis Receptor Kinase (SymRK) genes during nodulation and mycorrhizal infection in soybean (Glycine max).

    PubMed

    Indrasumunar, Arief; Wilde, Julia; Hayashi, Satomi; Li, Dongxue; Gresshoff, Peter M

    2015-03-15

    Association between legumes and rhizobia results in the formation of root nodules, where symbiotic nitrogen fixation occurs. The early stages of this association involve a complex of signalling events between the host and microsymbiont. Several genes dealing with early signal transduction have been cloned, and one of them encodes the leucine-rich repeat (LRR) receptor kinase (SymRK; also termed NORK). The Symbiosis Receptor Kinase gene is required by legumes to establish a root endosymbiosis with Rhizobium bacteria as well as mycorrhizal fungi. Using degenerate primer and BAC sequencing, we cloned duplicated SymRK homeologues in soybean called GmSymRKα and GmSymRKβ. These duplicated genes have high similarity of nucleotide (96%) and amino acid sequence (95%). Sequence analysis predicted a malectin-like domain within the extracellular domain of both genes. Several putative cis-acting elements were found in promoter regions of GmSymRKα and GmSymRKβ, suggesting a participation in lateral root development, cell division and peribacteroid membrane formation. The mutant of SymRK genes is not available in soybean; therefore, to know the functions of these genes, RNA interference (RNAi) of these duplicated genes was performed. For this purpose, RNAi construct of each gene was generated and introduced into the soybean genome by Agrobacterium rhizogenes-mediated hairy root transformation. RNAi of GmSymRKβ gene resulted in an increased reduction of nodulation and mycorrhizal infection than RNAi of GmSymRKα, suggesting it has the major activity of the duplicated gene pair. The results from the important crop legume soybean confirm the joint phenotypic action of GmSymRK genes in both mycorrhizal and rhizobial infection seen in model legumes.

  8. The molecular basis of bacterial-insect symbiosis

    PubMed Central

    Douglas, Angela E.

    2015-01-01

    Insects provide experimentally tractable and cost-effective model systems to investigate the molecular basis of animal-bacterial interactions. Recent research is revealing the central role of the insect innate immune system, especially anti-microbial peptides and reactive oxygen species, in regulating the abundance and composition of the microbiota in various insects, including Drosophila and the mosquitoes Aedes and Anopheles. Interactions between the immune system and microbiota are, however, bidirectional with evidence that members of the resident microbiota can promote immune function, conferring resistance to pathogens and parasites by both activation of immune effectors and production of toxins. Antagonistic and mutualistic interactions among bacteria have also been implicated as determinants of the microbiota composition, including exclusion of pathogens, but the molecular mechanisms are largely unknown. Some bacteria are crucial for insect nutrition, through provisioning of specific nutrients (e.g. B vitamins, essential amino acids) and modulation of the insect nutritional sensing and signaling pathways (e.g. insulin signaling) that regulate nutrient allocation, especially to lipid and other energy reserves. A key challenge for future research is to identify the molecular interaction between specific bacterial effectors and animal receptors, and to determine how these interactions translate into microbiota-dependent signaling, metabolism and immune function in the host. PMID:24735869

  9. The molecular basis of bacterial-insect symbiosis.

    PubMed

    Douglas, Angela E

    2014-11-25

    Insects provide experimentally tractable and cost-effective model systems to investigate the molecular basis of animal-bacterial interactions. Recent research is revealing the central role of the insect innate immune system, especially anti-microbial peptides and reactive oxygen species, in regulating the abundance and composition of the microbiota in various insects, including Drosophila and the mosquitoes Aedes and Anopheles. Interactions between the immune system and microbiota are, however, bidirectional with evidence that members of the resident microbiota can promote immune function, conferring resistance to pathogens and parasites by both activation of immune effectors and production of toxins. Antagonistic and mutualistic interactions among bacteria have also been implicated as determinants of the microbiota composition, including exclusion of pathogens, but the molecular mechanisms are largely unknown. Some bacteria are crucial for insect nutrition, through provisioning of specific nutrients (e.g., B vitamins, essential amino acids) and modulation of the insect nutritional sensing and signaling pathways (e.g., insulin signaling) that regulate nutrient allocation, especially to lipid and other energy reserves. A key challenge for future research is to identify the molecular interaction between specific bacterial effectors and animal receptors, as well as to determine how these interactions translate into microbiota-dependent signaling, metabolism, and immune function in the host.

  10. Burkholderia bacteria infectiously induce the proto-farming symbiosis of Dictyostelium amoebae and food bacteria

    PubMed Central

    DiSalvo, Susanne; Haselkorn, Tamara S.; Bashir, Usman; Jimenez, Daniela; Brock, Debra A.; Queller, David C.; Strassmann, Joan E.

    2015-01-01

    Symbiotic associations can allow an organism to acquire novel traits by accessing the genetic repertoire of its partner. In the Dictyostelium discoideum farming symbiosis, certain amoebas (termed “farmers”) stably associate with bacterial partners. Farmers can suffer a reproductive cost but also gain beneficial capabilities, such as carriage of bacterial food (proto-farming) and defense against competitors. Farming status previously has been attributed to amoeba genotype, but the role of bacterial partners in its induction has not been examined. Here, we explore the role of bacterial associates in the initiation, maintenance, and phenotypic effects of the farming symbiosis. We demonstrate that two clades of farmer-associated Burkholderia isolates colonize D. discoideum nonfarmers and infectiously endow them with farmer-like characteristics, indicating that Burkholderia symbionts are a major driver of the farming phenomenon. Under food-rich conditions, Burkholderia-colonized amoebas produce fewer spores than uncolonized counterparts, with the severity of this reduction being dependent on the Burkholderia colonizer. However, the induction of food carriage by Burkholderia colonization may be considered a conditionally adaptive trait because it can confer an advantage to the amoeba host when grown in food-limiting conditions. We observed Burkholderia inside and outside colonized D. discoideum spores after fruiting body formation; this observation, together with the ability of Burkholderia to colonize new amoebas, suggests a mixed mode of symbiont transmission. These results change our understanding of the D. discoideum farming symbiosis by establishing that the bacterial partner, Burkholderia, is an important causative agent of the farming phenomenon. PMID:26305954

  11. Metabolic Coevolution in the Bacterial Symbiosis of Whiteflies and Related Plant Sap-Feeding Insects

    PubMed Central

    Luan, Jun-Bo; Chen, Wenbo; Hasegawa, Daniel K.; Simmons, Alvin M.; Wintermantel, William M.; Ling, Kai-Shu; Fei, Zhangjun; Liu, Shu-Sheng; Douglas, Angela E.

    2015-01-01

    Genomic decay is a common feature of intracellular bacteria that have entered into symbiosis with plant sap-feeding insects. This study of the whitefly Bemisia tabaci and two bacteria (Portiera aleyrodidarum and Hamiltonella defensa) cohoused in each host cell investigated whether the decay of Portiera metabolism genes is complemented by host and Hamiltonella genes, and compared the metabolic traits of the whitefly symbiosis with other sap-feeding insects (aphids, psyllids, and mealybugs). Parallel genomic and transcriptomic analysis revealed that the host genome contributes multiple metabolic reactions that complement or duplicate Portiera function, and that Hamiltonella may contribute multiple cofactors and one essential amino acid, lysine. Homologs of the Bemisia metabolism genes of insect origin have also been implicated in essential amino acid synthesis in other sap-feeding insect hosts, indicative of parallel coevolution of shared metabolic pathways across multiple symbioses. Further metabolism genes coded in the Bemisia genome are of bacterial origin, but phylogenetically distinct from Portiera, Hamiltonella and horizontally transferred genes identified in other sap-feeding insects. Overall, 75% of the metabolism genes of bacterial origin are functionally unique to one symbiosis, indicating that the evolutionary history of metabolic integration in these symbioses is strongly contingent on the pattern of horizontally acquired genes. Our analysis, further, shows that bacteria with genomic decay enable host acquisition of complex metabolic pathways by multiple independent horizontal gene transfers from exogenous bacteria. Specifically, each horizontally acquired gene can function with other genes in the pathway coded by the symbiont, while facilitating the decay of the symbiont gene coding the same reaction. PMID:26377567

  12. Symbiosis induces widespread changes in the proteome of the model cnidarian Aiptasia.

    PubMed

    Oakley, Clinton A; Ameismeier, Michael F; Peng, Lifeng; Weis, Virginia M; Grossman, Arthur R; Davy, Simon K

    2016-07-01

    Coral reef ecosystems are metabolically founded on the mutualism between corals and photosynthetic dinoflagellates of the genus Symbiodinium. The glass anemone Aiptasia sp. has become a tractable model for this symbiosis, and recent advances in genetic information have enabled the use of mass spectrometry-based proteomics in this model. We utilized label-free liquid chromatography electrospray-ionization tandem mass spectrometry to analyze the effects of symbiosis on the proteomes of symbiotic and aposymbiotic Aiptasia. We identified and obtained relative quantification of more than 3,300 proteins in 1,578 protein clusters, with 81 protein clusters showing significantly different expression between symbiotic states. Symbiotic anemones showed significantly higher expression of proteins involved in lipid storage and transport, nitrogen transport and cycling, intracellular trafficking, endocytosis and inorganic carbon transport. These changes reflect shifts in host metabolism and nutrient reserves due to increased nutritional exchange with the symbionts, as well as mechanisms for supplying inorganic nutrients to the algae. Aposymbiotic anemones exhibited increased expression of multiple systems responsible for mediating reactive oxygen stress, suggesting that the host derives direct or indirect protection from oxidative stress while in symbiosis. Aposymbiotic anemones also increased their expression of an array of proteases and chitinases, indicating a metabolic shift from autotrophy to heterotrophy. These results provide a comprehensive Aiptasia proteome with more direct relative quantification of protein abundance than transcriptomic methods. The extension of "omics" techniques to this model system will allow more powerful studies of coral physiology, ecosystem function, and the effects of biotic and abiotic stress on the coral-dinoflagellate mutualism. PMID:26716757

  13. Metabolic Coevolution in the Bacterial Symbiosis of Whiteflies and Related Plant Sap-Feeding Insects.

    PubMed

    Luan, Jun-Bo; Chen, Wenbo; Hasegawa, Daniel K; Simmons, Alvin M; Wintermantel, William M; Ling, Kai-Shu; Fei, Zhangjun; Liu, Shu-Sheng; Douglas, Angela E

    2015-09-15

    Genomic decay is a common feature of intracellular bacteria that have entered into symbiosis with plant sap-feeding insects. This study of the whitefly Bemisia tabaci and two bacteria (Portiera aleyrodidarum and Hamiltonella defensa) cohoused in each host cell investigated whether the decay of Portiera metabolism genes is complemented by host and Hamiltonella genes, and compared the metabolic traits of the whitefly symbiosis with other sap-feeding insects (aphids, psyllids, and mealybugs). Parallel genomic and transcriptomic analysis revealed that the host genome contributes multiple metabolic reactions that complement or duplicate Portiera function, and that Hamiltonella may contribute multiple cofactors and one essential amino acid, lysine. Homologs of the Bemisia metabolism genes of insect origin have also been implicated in essential amino acid synthesis in other sap-feeding insect hosts, indicative of parallel coevolution of shared metabolic pathways across multiple symbioses. Further metabolism genes coded in the Bemisia genome are of bacterial origin, but phylogenetically distinct from Portiera, Hamiltonella and horizontally transferred genes identified in other sap-feeding insects. Overall, 75% of the metabolism genes of bacterial origin are functionally unique to one symbiosis, indicating that the evolutionary history of metabolic integration in these symbioses is strongly contingent on the pattern of horizontally acquired genes. Our analysis, further, shows that bacteria with genomic decay enable host acquisition of complex metabolic pathways by multiple independent horizontal gene transfers from exogenous bacteria. Specifically, each horizontally acquired gene can function with other genes in the pathway coded by the symbiont, while facilitating the decay of the symbiont gene coding the same reaction.

  14. Polyester synthesis genes associated with stress resistance are involved in an insect–bacterium symbiosis

    PubMed Central

    Kim, Jiyeun Kate; Won, Yeo Jin; Nikoh, Naruo; Nakayama, Hiroshi; Han, Sang Heum; Kikuchi, Yoshitomo; Rhee, Young Ha; Park, Ha Young; Kwon, Jeong Yun; Kurokawa, Kenji; Dohmae, Naoshi; Fukatsu, Takema; Lee, Bok Luel

    2013-01-01

    Many bacteria accumulate granules of polyhydroxyalkanoate (PHA) within their cells, which confer resistance to nutritional depletion and other environmental stresses. Here, we report an unexpected involvement of the bacterial endocellular storage polymer, PHA, in an insect–bacterium symbiotic association. The bean bug Riptortus pedestris harbors a beneficial and specific gut symbiont of the β-proteobacterial genus Burkholderia, which is orally acquired by host nymphs from the environment every generation and easily cultivable and genetically manipulatable. Biochemical and cytological comparisons between symbiotic and cultured Burkholderia detected more PHA granules consisting of poly-3-hydroxybutyrate and associated phasin (PhaP) protein in the symbiotic Burkholderia. Among major PHA synthesis genes, phaB and phaC were disrupted by homologous recombination together with the phaP gene, whereby ΔphaB, ΔphaC, and ΔphaP mutants were generated. Both in culture and in symbiosis, accumulation of PHA granules was strongly suppressed in ΔphaB and ΔphaC, but only moderately in ΔphaP. In symbiosis, the host insects infected with ΔphaB and ΔphaC exhibited significantly lower symbiont densities and smaller body sizes. These deficient phenotypes associated with ΔphaB and ΔphaC were restored by complementation of the mutants with plasmids encoding a functional phaB/phaC gene. Retention analysis of the plasmids revealed positive selection acting on the functional phaB/phaC in symbiosis. These results indicate that the PHA synthesis genes of the Burkholderia symbiont are required for normal symbiotic association with the Riptortus host. In vitro culturing analyses confirmed vulnerability of the PHA gene mutants to environmental stresses, suggesting that PHA may play a role in resisting stress under symbiotic conditions. PMID:23757494

  15. The prominent role of fungi and fungal enzymes in the ant-fungus biomass conversion symbiosis.

    PubMed

    Lange, L; Grell, M N

    2014-06-01

    Molecular studies have added significantly to understanding of the role of fungi and fungal enzymes in the efficient biomass conversion, which takes place in the fungus garden of leaf-cutting ants. It is now clear that the fungal symbiont expresses the full spectrum of genes for degrading cellulose and other plant cell wall polysaccharides. Since the start of the genomics era, numerous interesting studies have especially focused on evolutionary, molecular, and organismal aspects of the biological and biochemical functions of the symbiosis between leaf-cutting ants (Atta spp. and Acromyrmex spp.) and their fungal symbiont Leucoagaricus gongylophorus. Macroscopic observations of the fungus-farming ant colony inherently depict the ants as the leading part of the symbiosis (the myrmicocentric approach, overshadowing the mycocentric aspects). However, at the molecular level, it is fungal enzymes that enable the ants to access the nutrition embedded in recalcitrant plant biomass. Our hypothesis is that the evolutionary events that established fungus-farming practice were predisposed by a fascinating fungal evolution toward increasing attractiveness to ants. This resulted in the ants allowing the fungus to grow in the nests and began to supply plant materials for more fungal growth. Molecular studies also confirm that specialized fungal structures, the gongylidia, with high levels of proteins and rich blend of enzymes, are essential for symbiosis. Harvested and used as ant feed, the gongylidia are the key factor for sustaining the highly complex leaf-cutting ant colony. This microbial upgrade of fresh leaves to protein-enriched animal feed can serve as inspiration for modern biorefinery technology. PMID:24728757

  16. The prominent role of fungi and fungal enzymes in the ant-fungus biomass conversion symbiosis.

    PubMed

    Lange, L; Grell, M N

    2014-06-01

    Molecular studies have added significantly to understanding of the role of fungi and fungal enzymes in the efficient biomass conversion, which takes place in the fungus garden of leaf-cutting ants. It is now clear that the fungal symbiont expresses the full spectrum of genes for degrading cellulose and other plant cell wall polysaccharides. Since the start of the genomics era, numerous interesting studies have especially focused on evolutionary, molecular, and organismal aspects of the biological and biochemical functions of the symbiosis between leaf-cutting ants (Atta spp. and Acromyrmex spp.) and their fungal symbiont Leucoagaricus gongylophorus. Macroscopic observations of the fungus-farming ant colony inherently depict the ants as the leading part of the symbiosis (the myrmicocentric approach, overshadowing the mycocentric aspects). However, at the molecular level, it is fungal enzymes that enable the ants to access the nutrition embedded in recalcitrant plant biomass. Our hypothesis is that the evolutionary events that established fungus-farming practice were predisposed by a fascinating fungal evolution toward increasing attractiveness to ants. This resulted in the ants allowing the fungus to grow in the nests and began to supply plant materials for more fungal growth. Molecular studies also confirm that specialized fungal structures, the gongylidia, with high levels of proteins and rich blend of enzymes, are essential for symbiosis. Harvested and used as ant feed, the gongylidia are the key factor for sustaining the highly complex leaf-cutting ant colony. This microbial upgrade of fresh leaves to protein-enriched animal feed can serve as inspiration for modern biorefinery technology.

  17. Solar astrophysics - Ghettosis from, or symbiosis with, stellar and galactic astrophysics

    NASA Technical Reports Server (NTRS)

    Pecker, J.-C.; Thomas, R. N.

    1976-01-01

    The purpose of the paper is to show how the solar-stellar symbiotic approach has led to the modeling of a star as a concentration of matter and energy. By 'solar-stellar symbiosis' is meant the philosophy of investigation according to which one asks what change in our general understanding of stellar structure and of stellar spectroscopic diagnostics is required to satisfy both the sun and an unusual star when, for example, some feature of an unusual star is discovered. The evolution of stellar models is traced, from walled, thermodynamic-equilibrium models to de-isolated models featuring transition zones and nonlocal thermodynamic equilibrium.

  18. Is the evolution of the coral-algal symbiosis linked to fluctuations in seawater magnesium concentrations?

    NASA Astrophysics Data System (ADS)

    Giri, S.; Devlin, Q.; Swart, P. K.

    2014-12-01

    While Scleractinia first appear in shallow tropical seas during the Mid-Triassic, it is unclear when and why these corals established their symbiosis with a dinoflagellate alga (Symbiodinium microadriaticum). The development of this symbiosis was a major evolutionary innovation for corals, which was not previously observed in other coral taxa (Rugosa and Tabulata) and likely contributed to the rise of Scleractinia as the dominant reef builders. Inarguably, this symbiotic relationship is linked to increased calcification rates but dinoflagellate symbioses are also very common in non-calcifying marine invertebrates making it unclear whether the coral host or algal symbiont drives the establishment of this symbiosis. Recently, it has been suggested that the establishment of the coral-algal symbiosis is symbiont driven by the fluctuation of the Mg/Ca ratio of seawater at the beginning of the Mesozoic. Scleractinia precipitate aragonitic skeletons further suggesting they evolved in seawater with a high Mg/Ca ratio and that their mineralogy is linked to their environment. In order to determine how seawater chemistry influences host-symbiont interactions, we grew Pocillopora damicornis in seawater with elevated calcium and magnesium concentrations. Growth rates are higher than the control treatment when the Mg2+ concentration is increased by 200 ppm but are not significantly different than the control treatment when the Ca2+ concentration is increased by 200 ppm, suggesting that calcification is linked to the Mg2+ concentration of seawater. Growth rates are not, however, related to in-hospite symbiont density, which is similar in the control, +200 ppm Ca2+ and +200 ppm Mg2+ treatments. This similarity in symbiont density between treatments suggests that even when the chemistry of the surrounding seawater fluctuates, with respect to Ca2+ and Mg2+ ions, the coral host provides a stable environment in which the symbionts can reside. This preliminary work has implications for

  19. [Spermatocyte and ovum symbiosis, origin of ontogenesis and phylogenesis of metazoans].

    PubMed

    Costagliola, J

    1992-09-01

    The origin of metazoa implies the passage from an eukarote protozoan to a protozygote ancestor of a metazoan zygote. The most probable hypothesis is that of a symbiotic origin of the first zygote by association of two protists one signifying a spherical oocell and the other a flagellated spermatozoan; this could be the first step of the metazoan ontogenesis and therefore also of the phylogenesis. The genesis can also be explained by two haploid genomes NX NY, three gametes (two spermatozoa and one ovule), NX apparently being able to create both forms, and two zygotes. A double symbiosis, a chromosomic crossing-over and a selective expulsion can prove it.

  20. Interrelationships between mycorrhizal symbiosis, soil pH and plant sex modify the performance of Antennaria dioica

    NASA Astrophysics Data System (ADS)

    Varga, Sandra; Kytöviita, Minna-Maarit

    2010-05-01

    AM symbiosis is usually beneficial for plants, but the benefits gained may depend on the soil abiotic factors. In dioecious plants, female and male individuals have different resource demands and allocation patterns. As a consequence of these differences, it is logical to assume that female and male plants differ in their relationship with arbuscular mycorrhizal (AM) fungi, although this has rarely been examined. We used a factorial greenhouse experiment to investigate whether female and male plants in the dioecious model species Antennaria dioica have a different relationship with their AM symbionts under two soil pH levels. In particular, we asked: (1) Do the sexes in A. dioica have sex-specific benefits from AM symbiosis? (2) If so, which sex gains the highest benefit? (3) How does soil pH affect the sex - AM fungal relationship? Our results indicate that the sexes responded similarly to AM symbiosis and pH when mycorrhizal benefit was examined as growth and phosphorus accumulation. However, the sexes differed in response to AM symbiosis in terms of survival, as mortality was increased due to AM symbiosis in female plants whilst the opposite effect was detected in males. The plant-AM fungus relationship was significantly affected by soil pH as lowering the soil pH decreased the benefits gained by the plants from the mycorrhizal fungus. Taken together, our findings indicate that AM symbiosis is beneficial for plants depending on the life history trait considered. In addition, interactions between plants and their AM symbionts are modified by soil factors and the sex of the plant.

  1. The genome of Aiptasia, a sea anemone model for coral symbiosis.

    PubMed

    Baumgarten, Sebastian; Simakov, Oleg; Esherick, Lisl Y; Liew, Yi Jin; Lehnert, Erik M; Michell, Craig T; Li, Yong; Hambleton, Elizabeth A; Guse, Annika; Oates, Matt E; Gough, Julian; Weis, Virginia M; Aranda, Manuel; Pringle, John R; Voolstra, Christian R

    2015-09-22

    The most diverse marine ecosystems, coral reefs, depend upon a functional symbiosis between a cnidarian animal host (the coral) and intracellular photosynthetic dinoflagellate algae. The molecular and cellular mechanisms underlying this endosymbiosis are not well understood, in part because of the difficulties of experimental work with corals. The small sea anemone Aiptasia provides a tractable laboratory model for investigating these mechanisms. Here we report on the assembly and analysis of the Aiptasia genome, which will provide a foundation for future studies and has revealed several features that may be key to understanding the evolution and function of the endosymbiosis. These features include genomic rearrangements and taxonomically restricted genes that may be functionally related to the symbiosis, aspects of host dependence on alga-derived nutrients, a novel and expanded cnidarian-specific family of putative pattern-recognition receptors that might be involved in the animal-algal interactions, and extensive lineage-specific horizontal gene transfer. Extensive integration of genes of prokaryotic origin, including genes for antimicrobial peptides, presumably reflects an intimate association of the animal-algal pair also with its prokaryotic microbiome. PMID:26324906

  2. Functional significance of genetically different symbiotic algae Symbiodinium in a coral reef symbiosis.

    PubMed

    Loram, J E; Trapido-Rosenthal, H G; Douglas, A E

    2007-11-01

    The giant sea anemone Condylactis gigantea associates with members of two clades of the dinoflagellate alga Symbiodinium, either singly or in mixed infection, as revealed by clade-specific quantitative polymerase chain reaction of large subunit ribosomal DNA. To explore the functional significance of this molecular variation, the fate of photosynthetically fixed carbon was investigated by (14)C radiotracer experiments. Symbioses with algae of clades A and B released ca. 30-40% of fixed carbon to the animal tissues. Incorporation into the lipid fraction and the low molecular weight fraction dominated by amino acids was significantly higher in symbioses with algae of clade A than of clade B, suggesting that the genetically different algae in C. gigantea are not functionally equivalent. Symbioses with mixed infections yielded intermediate values, such that this functional trait of the symbiosis can be predicted from the traits of the contributing algae. Coral and sea anemone symbioses with Symbiodinium break down at elevated temperature, a process known as 'coral bleaching'. The functional response of the C. gigantea symbiosis to heat stress varied between the algae of clades A and B, with particularly depressed incorporation of photosynthetic carbon into lipid of the clade B algae, which are more susceptible to high temperature than the algae of clade A. This study provides a first exploration of how the core symbiotic function of photosynthate transfer to the host varies with the genotype of Symbiodinium, an algal symbiont which underpins corals and, hence, coral reef ecosystems. PMID:17868294

  3. Photosynthetic aeration in biological wastewater treatment using immobilized microalgae-bacteria symbiosis.

    PubMed

    Praveen, Prashant; Loh, Kai-Chee

    2015-12-01

    Chlorella vulgaris encapsulated in alginate beads were added into a bioreactor treating synthetic wastewater using Pseudomonas putida. A symbiotic CO2/O2 gas exchange was established between the two microorganisms for photosynthetic aeration of wastewater. During batch operation, glucose removal efficiency in the bioreactor improved from 50% in 12 h without aeration to 100% in 6 h, when the bioreactor was aerated photosynthetically. During continuous operation, the bioreactor was operated at a low hydraulic retention time of 3.3 h at feed concentrations of 250 and 500 mg/L glucose. The removal efficiency at 500 mg/L increased from 73% without aeration to 100% in the presence of immobilized microalgae. The initial microalgae concentration was critical to achieve adequate aeration, and the removal rate increased with increasing microalgae concentration. The highest removal rate of 142 mg/L-h glucose was achieved at an initial microalgae concentration of 190 mg/L. Quantification of microalgae growth in the alginate beads indicated an exponential growth during symbiosis, indicating that the bioreactor performance was limited by oxygen production rates. Under symbiotic conditions, the chlorophyll content of the immobilized microalgae increased by more than 30%. These results indicate that immobilized microalgae in symbiosis with heterotrophic bacteria are promising in wastewater aeration. PMID:26266755

  4. Protein actors sustaining arbuscular mycorrhizal symbiosis: underground artists break the silence.

    PubMed

    Recorbet, Ghislaine; Abdallah, Cosette; Renaut, Jenny; Wipf, Daniel; Dumas-Gaudot, Eliane

    2013-07-01

    The roots of most land plants can enter a relationship with soil-borne fungi belonging to the phylum Glomeromycota. This symbiosis with arbuscular mycorrhizal (AM) fungi belongs to the so-called biotrophic interactions, involving the intracellular accommodation of a microorganism by a living plant cell without causing the death of the host. Although profiling technologies have generated an increasing depository of plant and fungal proteins eligible for sustaining AM accommodation and functioning, a bottleneck exists for their functional analysis as these experiments are difficult to carry out with mycorrhiza. Nonetheless, the expansion of gene-to-phenotype reverse genetic tools, including RNA interference and transposon silencing, have recently succeeded in elucidating some of the plant-related protein candidates. Likewise, despite the ongoing absence of transformation tools for AM fungi, host-induced gene silencing has allowed knockdown of fungal gene expression in planta for the first time, thus unlocking a technological limitation in deciphering the functional pertinence of glomeromycotan proteins during mycorrhizal establishment. This review is thus intended to draw a picture of our current knowledge about the plant and fungal protein actors that have been demonstrated to be functionally implicated in sustaining AM symbiosis mostly on the basis of silencing approaches.

  5. The Rhizobium etli opt operon is required for symbiosis and stress resistance.

    PubMed

    Vos, K; Braeken, K; Fauvart, M; Ndayizeye, M; Verhaert, J; Zachurzok, S; Lambrichts, I; Michiels, J

    2007-07-01

    Rhizobium etli is a Gram-negative root-colonizing soil bacterium capable of fixing nitrogen while living in symbiosis with its leguminous host Phaseolus vulgaris. A genome-wide screening for R. etli symbiotic mutants revealed a R. etli operon encoding an oligopeptide ABC-transporter (Opt), two redA homologous genes and one redB gene. Expression analysis showed this opt operon to be transcribed both under free-living and symbiotic conditions and expression levels were demonstrated to be growth-phase-dependent. Plants nodulated by R. etli opt mutants showed a reduced symbiotic nitrogen fixation activity (approximately 50% reduction). Growth experiments with opt mutants in the presence of oligopeptides as the sole nitrogen source confirmed the involvement of the opt genes in oligopeptide uptake. Further phenotypic analysis of the opt mutants revealed them to display an enhanced resistance to the oligopeptide antibiotic bacitracin, an increased susceptibility to the beta-lactam antibiotic ampicillin and a decreased osmotolerance. In conclusion, our results demonstrate that the opt operon plays a crucial role during symbiosis and stress resistance. PMID:17564602

  6. Phage loss and the breakdown of a defensive symbiosis in aphids.

    PubMed

    Weldon, S R; Strand, M R; Oliver, K M

    2013-01-22

    Terrestrial arthropods are often infected with heritable bacterial symbionts, which may themselves be infected by bacteriophages. However, what role, if any, bacteriophages play in the regulation and maintenance of insect-bacteria symbioses is largely unknown. Infection of the aphid Acyrthosiphon pisum by the bacterial symbiont Hamiltonella defensa confers protection against parasitoid wasps, but only when H. defensa is itself infected by the phage A. pisum secondary endosymbiont (APSE). Here, we use a controlled genetic background and correlation-based assays to show that loss of APSE is associated with up to sevenfold increases in the intra-aphid abundance of H. defensa. APSE loss is also associated with severe deleterious effects on aphid fitness: aphids infected with H. defensa lacking APSE have a significantly delayed onset of reproduction, lower weight at adulthood and half as many total offspring as aphids infected with phage-harbouring H. defensa, indicating that phage loss can rapidly lead to the breakdown of the defensive symbiosis. Our results overall indicate that bacteriophages play critical roles in both aphid defence and the maintenance of heritable symbiosis.

  7. Preventing overexploitation in a mutualism: partner regulation in the crayfish-branchiobdellid symbiosis.

    PubMed

    Farrell, Kaitlin J; Creed, Robert P; Brown, Bryan L

    2014-02-01

    For a symbiosis to be a mutualism, benefits received must exceed costs incurred for both partners. Partners can prevent costly overexploitation through behaviors that moderate interactions with the other symbiont. In a symbiosis between crayfish and branchiobdellidan annelids, the worms can increase crayfish survival and growth by removing fouling material from the gills. However, overexploitation by the worms is possible and results in damage to host gills. We used behavioral observations to assess the degree to which two species of crayfish (Cambarus chasmodactylus and Orconectes cristavarius) use grooming to moderate their interaction with branchiobdellids. We found that grooming could effectively reduce worm numbers, and the proportion of total grooming directed at worms differed between crayfish species and as a function of worm number. O. cristavarius increased grooming in response to the addition of a single worm, while C. chasmodactylus only increased grooming in response to ten worms. These differences in the number of worms that trigger grooming behavior reflect differences between crayfish species in field settings. We also assessed whether antibacterial compounds in circulating crayfish hemolymph could limit bacterial gill fouling. O. cristavarius hemolymph inhibited some test bacteria more effectively than C. chasmodactylus did. Differences in the antibacterial properties of crayfish hemolymph may therefore help explain differences in both worm-directed grooming and worm loads in the field. We conclude that crayfish can use grooming to reduce worm numbers, which could lower the potential for gill damage, and that the level of grooming varies between crayfish species.

  8. Photosynthetic aeration in biological wastewater treatment using immobilized microalgae-bacteria symbiosis.

    PubMed

    Praveen, Prashant; Loh, Kai-Chee

    2015-12-01

    Chlorella vulgaris encapsulated in alginate beads were added into a bioreactor treating synthetic wastewater using Pseudomonas putida. A symbiotic CO2/O2 gas exchange was established between the two microorganisms for photosynthetic aeration of wastewater. During batch operation, glucose removal efficiency in the bioreactor improved from 50% in 12 h without aeration to 100% in 6 h, when the bioreactor was aerated photosynthetically. During continuous operation, the bioreactor was operated at a low hydraulic retention time of 3.3 h at feed concentrations of 250 and 500 mg/L glucose. The removal efficiency at 500 mg/L increased from 73% without aeration to 100% in the presence of immobilized microalgae. The initial microalgae concentration was critical to achieve adequate aeration, and the removal rate increased with increasing microalgae concentration. The highest removal rate of 142 mg/L-h glucose was achieved at an initial microalgae concentration of 190 mg/L. Quantification of microalgae growth in the alginate beads indicated an exponential growth during symbiosis, indicating that the bioreactor performance was limited by oxygen production rates. Under symbiotic conditions, the chlorophyll content of the immobilized microalgae increased by more than 30%. These results indicate that immobilized microalgae in symbiosis with heterotrophic bacteria are promising in wastewater aeration.

  9. Occurrence of a specific dual symbiosis in the excretory organ of geographically distant Nautiloids populations.

    PubMed

    Pernice, Mathieu; Boucher-Rodoni, Renata

    2012-10-01

    Nautilus is one of the most intriguing of all sea creatures, sharing morphological similarities with the extinct forms of coiled cephalopods that evolved since the Cambrian (542-488 mya). Further, bacterial symbioses found in their excretory organ are of particular interest as they provide a great opportunity to investigate the influence of host-microbe interactions upon the origin and evolution of an innovative nitrogen excretory system. To establish the potential of Nautilus excretory organ as a new symbiotic system, it is, however, necessary to assess the specificity of this symbiosis and whether it is consistent within the different species of present-day Nautiloids. By addressing the phylogeny and distribution of bacterial symbionts in three Nautilus populations separated by more than 6000 km (N. pompilius from Philippines and Vanuatu, and N. macromphalus from New Caledonia), this study confirms the specificity of this dual symbiosis involving the presence of betaproteobacteria and spirochaete symbionts on a very wide geographical area. Overall, this work sheds further light on Nautiloids excretory organ as an innovative system of interaction between bacteria and cephalopods.

  10. The genome of Aiptasia, a sea anemone model for coral symbiosis

    PubMed Central

    Baumgarten, Sebastian; Simakov, Oleg; Esherick, Lisl Y.; Liew, Yi Jin; Lehnert, Erik M.; Michell, Craig T.; Li, Yong; Hambleton, Elizabeth A.; Guse, Annika; Oates, Matt E.; Gough, Julian; Weis, Virginia M.; Aranda, Manuel; Pringle, John R.; Voolstra, Christian R.

    2015-01-01

    The most diverse marine ecosystems, coral reefs, depend upon a functional symbiosis between a cnidarian animal host (the coral) and intracellular photosynthetic dinoflagellate algae. The molecular and cellular mechanisms underlying this endosymbiosis are not well understood, in part because of the difficulties of experimental work with corals. The small sea anemone Aiptasia provides a tractable laboratory model for investigating these mechanisms. Here we report on the assembly and analysis of the Aiptasia genome, which will provide a foundation for future studies and has revealed several features that may be key to understanding the evolution and function of the endosymbiosis. These features include genomic rearrangements and taxonomically restricted genes that may be functionally related to the symbiosis, aspects of host dependence on alga-derived nutrients, a novel and expanded cnidarian-specific family of putative pattern-recognition receptors that might be involved in the animal–algal interactions, and extensive lineage-specific horizontal gene transfer. Extensive integration of genes of prokaryotic origin, including genes for antimicrobial peptides, presumably reflects an intimate association of the animal–algal pair also with its prokaryotic microbiome. PMID:26324906

  11. Experimental evidence of a symbiosis between red-cockaded woodpeckers and fungi.

    PubMed

    Jusino, Michelle A; Lindner, Daniel L; Banik, Mark T; Rose, Kevin R; Walters, Jeffrey R

    2016-03-30

    Primary cavity excavators, such as woodpeckers, are ecosystem engineers in many systems. Associations between cavity excavators and fungi have long been hypothesized to facilitate cavity excavation, but these relationships have not been experimentally verified. Fungi may help excavators by softening wood, while excavators may facilitate fungal dispersal. Here we demonstrate that excavators facilitate fungal dispersal and thus we report the first experimental evidence of a symbiosis between fungi and a cavity excavator, the red-cockaded woodpecker (RCW,Picoides borealis). Swab samples of birds showed that RCWs carry fungal communities similar to those found in their completed excavations. A 26-month field experiment using human-made aseptically drilled excavations in live trees, half of which were inaccessible to RCWs, demonstrated that RCWs directly alter fungal colonization and community composition. Experimental excavations that were accessible to RCWs contained fungal communities similar to natural RCW excavations, whereas inaccessible experimental excavations contained significantly different fungal communities. Our work demonstrates a complex symbiosis between cavity excavators and communities of fungi, with implications for forest ecology, wildlife management, and conservation. PMID:27009222

  12. Cleaning symbiosis as an evolutionary game: To cheat or not to cheat?

    PubMed

    Poulin; Vickery

    1995-07-01

    Cleaning symbiosis is an apparently mutualistic relationship, occurring in diverse taxa, in which cleaners remove ectoparasites from the body of their clients. Here its evolution is explored with a simple game theory model in which both participants play against each other using either honest or cheating strategies. Honest clients pose for cleaners and have their ectoparasites removed, cheating clients eat the cleaners. Honest cleaners eat their clients' ectoparasites, cheating cleaners feed mainly on client tissues. The conditions that favour either strategy are obtained when the game is resolved: (i) the cost of being cleaned by a cheat and the proportion of cheats in the cleaner population determine the relative value of honesty in clients, and (ii) the advantages of being an honest cleaner depend on the relative fitness value of ectoparasites as food versus client tissues. A scenario for the origin of the cleaning symbiosis can also be derived from the model, in which the specialization of both participants need not be simultaneous. The model is based on the relationship between specialized cleaner fish and their client fish on coral reefs, but its conclusions are used in an examination of other cleaning associations. Copyright 1995 Academic Press Limited PMID:9441815

  13. Bacterial Symbiosis Maintenance in the Asexually Reproducing and Regenerating Flatworm Paracatenula galateia

    PubMed Central

    Dirks, Ulrich; Gruber-Vodicka, Harald R.; Leisch, Nikolaus; Bulgheresi, Silvia; Egger, Bernhard; Ladurner, Peter; Ott, Jörg A.

    2012-01-01

    Bacteriocytes set the stage for some of the most intimate interactions between animal and bacterial cells. In all bacteriocyte possessing systems studied so far, de novo formation of bacteriocytes occurs only once in the host development, at the time of symbiosis establishment. Here, we present the free-living symbiotic flatworm Paracatenula galateia and its intracellular, sulfur-oxidizing bacteria as a system with previously undescribed strategies of bacteriocyte formation and bacterial symbiont transmission. Using thymidine analogue S-phase labeling and immunohistochemistry, we show that all somatic cells in adult worms – including bacteriocytes – originate exclusively from aposymbiotic stem cells (neoblasts). The continued bacteriocyte formation from aposymbiotic stem cells in adult animals represents a previously undescribed strategy of symbiosis maintenance and makes P. galateia a unique system to study bacteriocyte differentiation and development. We also provide morphological and immunohistochemical evidence that P. galateia reproduces by asexual fragmentation and regeneration (paratomy) and, thereby, vertically transmits numerous symbiont-containing bacteriocytes to its asexual progeny. Our data support the earlier reported hypothesis that the symbiont population is subjected to reduced bottleneck effects. This would justify both the codiversification between Paracatenula hosts and their Candidatus Riegeria symbionts, and the slow evolutionary rates observed for several symbiont genes. PMID:22509347

  14. Bacterial symbiosis maintenance in the asexually reproducing and regenerating flatworm Paracatenula galateia.

    PubMed

    Dirks, Ulrich; Gruber-Vodicka, Harald R; Leisch, Nikolaus; Bulgheresi, Silvia; Egger, Bernhard; Ladurner, Peter; Ott, Jörg A

    2012-01-01

    Bacteriocytes set the stage for some of the most intimate interactions between animal and bacterial cells. In all bacteriocyte possessing systems studied so far, de novo formation of bacteriocytes occurs only once in the host development, at the time of symbiosis establishment. Here, we present the free-living symbiotic flatworm Paracatenula galateia and its intracellular, sulfur-oxidizing bacteria as a system with previously undescribed strategies of bacteriocyte formation and bacterial symbiont transmission. Using thymidine analogue S-phase labeling and immunohistochemistry, we show that all somatic cells in adult worms - including bacteriocytes - originate exclusively from aposymbiotic stem cells (neoblasts). The continued bacteriocyte formation from aposymbiotic stem cells in adult animals represents a previously undescribed strategy of symbiosis maintenance and makes P. galateia a unique system to study bacteriocyte differentiation and development. We also provide morphological and immunohistochemical evidence that P. galateia reproduces by asexual fragmentation and regeneration (paratomy) and, thereby, vertically transmits numerous symbiont-containing bacteriocytes to its asexual progeny. Our data support the earlier reported hypothesis that the symbiont population is subjected to reduced bottleneck effects. This would justify both the codiversification between Paracatenula hosts and their Candidatus Riegeria symbionts, and the slow evolutionary rates observed for several symbiont genes.

  15. A Peptidoglycan-Remodeling Enzyme Is Critical for Bacteroid Differentiation in Bradyrhizobium spp. During Legume Symbiosis.

    PubMed

    Gully, Djamel; Gargani, Daniel; Bonaldi, Katia; Grangeteau, Cédric; Chaintreuil, Clémence; Fardoux, Joël; Nguyen, Phuong; Marchetti, Roberta; Nouwen, Nico; Molinaro, Antonio; Mergaert, Peter; Giraud, Eric

    2016-06-01

    In response to the presence of compatible rhizobium bacteria, legumes form symbiotic organs called nodules on their roots. These nodules house nitrogen-fixing bacteroids that are a differentiated form of the rhizobium bacteria. In some legumes, the bacteroid differentiation comprises a dramatic cell enlargement, polyploidization, and other morphological changes. Here, we demonstrate that a peptidoglycan-modifying enzyme in Bradyrhizobium strains, a DD-carboxypeptidase that contains a peptidoglycan-binding SPOR domain, is essential for normal bacteroid differentiation in Aeschynomene species. The corresponding mutants formed bacteroids that are malformed and hypertrophied. However, in soybean, a plant that does not induce morphological differentiation of its symbiont, the mutation does not affect the bacteroids. Remarkably, the mutation also leads to necrosis in a large fraction of the Aeschynomene nodules, indicating that a normally formed peptidoglycan layer is essential for avoiding the induction of plant immune responses by the invading bacteria. In addition to exopolysaccharides, capsular polysaccharides, and lipopolysaccharides, whose role during symbiosis is well defined, our work demonstrates an essential role in symbiosis for yet another rhizobial envelope component, the peptidoglycan layer.

  16. The first thousand days - intestinal microbiology of early life: establishing a symbiosis.

    PubMed

    Wopereis, Harm; Oozeer, Raish; Knipping, Karen; Belzer, Clara; Knol, Jan

    2014-08-01

    The development of the intestinal microbiota in the first years of life is a dynamic process significantly influenced by early-life nutrition. Pioneer bacteria colonizing the infant intestinal tract and the gradual diversification to a stable climax ecosystem plays a crucial role in establishing host-microbe interactions essential for optimal symbiosis. This colonization process and establishment of symbiosis may profoundly influence health throughout life. Recent developments in microbiologic cultivation-independent methods allow a detailed view of the key players and factors involved in this process and may further elucidate their roles in a healthy gut and immune maturation. Aberrant patterns may lead to identifying key microbial signatures involved in developing immunologic diseases into adulthood, such as asthma and atopic diseases. The central role of early-life nutrition in the developmental human microbiota, immunity, and metabolism offers promising strategies for prevention and treatment of such diseases. This review provides an overview of the development of the intestinal microbiota, its bidirectional relationship with the immune system, and its role in impacting health and disease, with emphasis on allergy, in early life.

  17. The genome of Aiptasia, a sea anemone model for coral symbiosis.

    PubMed

    Baumgarten, Sebastian; Simakov, Oleg; Esherick, Lisl Y; Liew, Yi Jin; Lehnert, Erik M; Michell, Craig T; Li, Yong; Hambleton, Elizabeth A; Guse, Annika; Oates, Matt E; Gough, Julian; Weis, Virginia M; Aranda, Manuel; Pringle, John R; Voolstra, Christian R

    2015-09-22

    The most diverse marine ecosystems, coral reefs, depend upon a functional symbiosis between a cnidarian animal host (the coral) and intracellular photosynthetic dinoflagellate algae. The molecular and cellular mechanisms underlying this endosymbiosis are not well understood, in part because of the difficulties of experimental work with corals. The small sea anemone Aiptasia provides a tractable laboratory model for investigating these mechanisms. Here we report on the assembly and analysis of the Aiptasia genome, which will provide a foundation for future studies and has revealed several features that may be key to understanding the evolution and function of the endosymbiosis. These features include genomic rearrangements and taxonomically restricted genes that may be functionally related to the symbiosis, aspects of host dependence on alga-derived nutrients, a novel and expanded cnidarian-specific family of putative pattern-recognition receptors that might be involved in the animal-algal interactions, and extensive lineage-specific horizontal gene transfer. Extensive integration of genes of prokaryotic origin, including genes for antimicrobial peptides, presumably reflects an intimate association of the animal-algal pair also with its prokaryotic microbiome.

  18. Fungal symbiosis and precipitation alter traits and dune building by the ecosystem engineer, Ammophila breviligulata.

    PubMed

    Emery, Sarah M; Bell-Dereske, Lukas; Rudgers, Jennifer A

    2015-04-01

    Ecosystem engineer species influence their community and ecosystem by creating or altering the physical structure of habitats. The function of ecosystem engineers is variable and can depend on both abiotic and biotic factors. Here we make use of a primary successional system to evaluate the direct and interactive effects of climate change (precipitation) and fungal endophyte symbiosis on population traits and ecosystem function of the ecosystem engineering grass species, Ammophila breviligulata. We manipulated endophyte presence in A. breviligulata in combination with rain-out shelters and rainfall additions in a factorial field experiment established in 2010 on Lake Michigan sand dunes. We monitored plant traits, survival, growth, and sexual reproduction of A. breviligulata from 2010-2013, and quantified ecosystem engineering as the sand accumulation rate. Presence of the endophyte in A. breviligulata increased vegetative growth by up to 19%, and reduced sexual reproduction by up to 46% across all precipitation treatments. Precipitation was a less significant factor than endophyte colonization for A. breviligulata growth. Reduced precipitation increased average leaf number per tiller but had no other effects on plant traits. Changes in A. breviligulata traits corresponded to increases in sand accumulation in plots with the endophyte as well as in plots with reduced precipitation. Sand accumulation is a key ecosystem function in these primary successional habitats, and so microbial symbiosis in this ecosystem engineer could lead to direct effects on the value of these dune habitats for humans.

  19. Nitric oxide: a multifaceted regulator of the nitrogen-fixing symbiosis.

    PubMed

    Hichri, Imène; Boscari, Alexandre; Castella, Claude; Rovere, Martina; Puppo, Alain; Brouquisse, Renaud

    2015-05-01

    The specific interaction between legumes and Rhizobium-type bacteria leads to the establishment of a symbiotic relationship characterized by the formation of new differentiated organs named nodules, which provide a niche for bacterial nitrogen (N2) fixation. In the nodules, bacteria differentiate into bacteroids with the ability to fix atmospheric N2 via nitrogenase activity. As nitrogenase is strongly inhibited by oxygen, N2 fixation is made possible by the microaerophilic conditions prevailing in the nodules. Increasing evidence has shown the presence of NO during symbiosis, from early interaction steps between the plant and the bacterial partners to N2-fixing and senescence steps in mature nodules. Both the plant and the bacterial partners participate in NO synthesis. NO was found to be required for the optimal establishment of the symbiotic interaction. Transcriptomic analysis at an early stage of the symbiosis showed that NO is potentially involved in the repression of plant defence reactions, favouring the establishment of the plant-microbe interaction. In mature nodules, NO was shown to inhibit N2 fixation, but it was also demonstrated to have a regulatory role in nitrogen metabolism, to play a beneficial metabolic function for the maintenance of the energy status under hypoxic conditions, and to trigger nodule senescence. The present review provides an overview of NO sources and multifaceted effects from the early steps of the interaction to the senescence of the nodule, and presents several approaches which appear to be particularly promising in deciphering the roles of NO in N2-fixing symbioses.

  20. An integrated functional approach to dissect systemic responses in maize to arbuscular mycorrhizal symbiosis.

    PubMed

    Gerlach, Nina; Schmitz, Jessica; Polatajko, Aleksandra; Schlüter, Urte; Fahnenstich, Holger; Witt, Sandra; Fernie, Alisdair R; Uroic, Kalle; Scholz, Uwe; Sonnewald, Uwe; Bucher, Marcel

    2015-08-01

    Most terrestrial plants benefit from the symbiosis with arbuscular mycorrhizal fungi (AMF) mainly under nutrient-limited conditions. Here the crop plant Zea mays was grown with and without AMF in a bi-compartmented system separating plant and phosphate (Pi) source by a hyphae-permeable membrane. Thus, Pi was preferentially taken up via the mycorrhizal Pi uptake pathway while other nutrients were ubiquitously available. To study systemic effects of mycorrhizal Pi uptake on leaf status, leaves of these plants that display an increased biomass in the presence of AMF were subjected to simultaneous ionomic, transcriptomic and metabolomic analyses. We observed robust changes of the leaf elemental composition, that is, increase of P, S and Zn and decrease of Mn, Co and Li concentration in mycorrhizal plants. Although changes in anthocyanin and lipid metabolism point to an improved P status, a global increase in C versus N metabolism highlights the redistribution of metabolic pools including carbohydrates and amino acids. Strikingly, an induction of systemic defence gene expression and concomitant accumulation of secondary metabolites such as the terpenoids alpha- and beta-amyrin suggest priming of mycorrhizal maize leaves as a mycorrhiza-specific response. This work emphasizes the importance of AM symbiosis for the physiological status of plant leaves and could lead to strategies for optimized breeding of crop species with high growth potential.

  1. Nodule carbohydrate catabolism is enhanced in the Medicago truncatula A17-Sinorhizobium medicae WSM419 symbiosis

    PubMed Central

    Larrainzar, Estíbaliz; Gil-Quintana, Erena; Seminario, Amaia; Arrese-Igor, Cesar; González, Esther M.

    2014-01-01

    The symbiotic association between Medicago truncatula and Sinorhizobium meliloti is a well-established model system in the legume–Rhizobium community. Despite its wide use, the symbiotic efficiency of this model has been recently questioned and an alternative microsymbiont, S. medicae, has been proposed. However, little is known about the physiological mechanisms behind the higher symbiotic efficiency of S. medicae WSM419. In the present study, we inoculated M. truncatula Jemalong A17 with either S. medicae WSM419 or S. meliloti 2011 and compared plant growth, photosynthesis, N2-fixation rates, and plant nodule carbon and nitrogen metabolic activities in the two systems. M. truncatula plants in symbiosis with S. medicae showed increased biomass and photosynthesis rates per plant. Plants grown in symbiosis with S. medicae WSM419 also showed higher N2-fixation rates, which were correlated with a larger nodule biomass, while nodule number was similar in both systems. In terms of plant nodule metabolism, M. truncatula–S. medicae WSM419 nodules showed increased sucrose-catabolic activity, mostly associated with sucrose synthase, accompanied by a reduced starch content, whereas nitrogen-assimilation activities were comparable to those measured in nodules infected with S. meliloti 2011. Taken together, these results suggest that S. medicae WSM419 is able to enhance plant carbon catabolism in M. truncatula nodules, which allows for the maintaining of high symbiotic N2-fixation rates, better growth and improved general plant performance. PMID:25221545

  2. 7 CFR 1212.20 - Promotion.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE HONEY PACKERS AND IMPORTERS RESEARCH, PROMOTION, CONSUMER EDUCATION AND INDUSTRY INFORMATION ORDER Honey Packers and Importers Research, Promotion, Consumer Education, and Industry Information Order Definitions § 1212.20 Promotion. “Promotion” means...

  3. [Friar José Mariano da Conceição Veloso and the promotion of industrial techniques in colonial Brazil: discussion of some concepts from the chemical sciences].

    PubMed

    Luna, Fernando J

    2009-01-01

    At the turn of the 19th century, Minas Gerais Botanist Friar Veloso worked intensely on the publication of books to promote among settlers from the Portuguese empire techniques for improving agricultural production and from the incipient chemistry industry. This article analyzes the first volume of the "Alographia dos alkalis fixos...", a work that includes articles, book chapters, letters and patents from ten authors, particularly French and English, about the scientific and technical knowledge needed for the production of potassium carbonate from the ash of native plants. Some concepts and definitions used at the time of the Chemical Revolution are discussed, considering that Veloso translated them to Portuguese and introduced them to Brazil through his work.

  4. Arbuscular mycorrhizal symbiosis can mitigate the negative effects of night warming on physiological traits of Medicago truncatula L.

    PubMed

    Hu, Yajun; Wu, Songlin; Sun, Yuqing; Li, Tao; Zhang, Xin; Chen, Caiyan; Lin, Ge; Chen, Baodong

    2015-02-01

    Elevated night temperature, one of the main climate warming scenarios, can have profound effects on plant growth and metabolism. However, little attention has been paid to the potential role of mycorrhizal associations in plant responses to night warming, although it is well known that symbiotic fungi can protect host plants against various environmental stresses. In the present study, physiological traits of Medicago truncatula L. in association with the arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis were investigated under simulated night warming. A constant increase in night temperature of 1.53 °C significantly reduced plant shoot and root biomass, flower and seed number, leaf sugar concentration, and shoot Zn and root P concentrations. However, the AM association essentially mitigated these negative effects of night warming by improving plant growth, especially through increased root biomass, root to shoot ratio, and shoot Zn and root P concentrations. A significant interaction was observed between R. irregularis inoculation and night warming in influencing both root sucrose concentration and expression of sucrose synthase (SusS) genes, suggesting that AM symbiosis and increased night temperature jointly regulated plant sugar metabolism. Night warming stimulated AM fungal colonization but did not influence arbuscule abundance, symbiosis-related plant or fungal gene expression, or growth of extraradical mycelium, indicating little effect of night warming on the development or functioning of AM symbiosis. These findings highlight the importance of mycorrhizal symbiosis in assisting plant resilience to climate warming. PMID:25033924

  5. Menthol-induced bleaching rapidly and effectively provides experimental aposymbiotic sea anemones (Aiptasia sp.) for symbiosis investigations.

    PubMed

    Matthews, Jennifer L; Sproles, Ashley E; Oakley, Clinton A; Grossman, Arthur R; Weis, Virginia M; Davy, Simon K

    2016-02-01

    Experimental manipulation of the symbiosis between cnidarians and photosynthetic dinoflagellates (Symbiodinium spp.) is crucial to advancing the understanding of the cellular mechanisms involved in host-symbiont interactions, and overall coral reef ecology. The anemone Aiptasia sp. is a model for cnidarian-dinoflagellate symbiosis, and notably it can be rendered aposymbiotic (i.e. dinoflagellate-free) and re-infected with a range of Symbiodinium types. Various methods exist for generating aposymbiotic hosts; however, they can be hugely time consuming and not wholly effective. Here, we optimise a method using menthol for production of aposymbiotic Aiptasia. The menthol treatment produced aposymbiotic hosts within just 4 weeks (97-100% symbiont loss), and the condition was maintained long after treatment when anemones were held under a standard light:dark cycle. The ability of Aiptasia to form a stable symbiosis appeared to be unaffected by menthol exposure, as demonstrated by successful re-establishment of the symbiosis when anemones were experimentally re-infected. Furthermore, there was no significant impact on photosynthetic or respiratory performance of re-infected anemones. PMID:26596538

  6. Integrating DNA Methylation and Gene Expression Data in the Development of the Soybean-Bradyrhizobium N2-Fixing Symbiosis

    PubMed Central

    Davis-Richardson, Austin G.; Russell, Jordan T.; Dias, Raquel; McKinlay, Andrew J.; Canepa, Ronald; Fagen, Jennie R.; Rusoff, Kristin T.; Drew, Jennifer C.; Kolaczkowski, Bryan; Emerich, David W.; Triplett, Eric W.

    2016-01-01

    Very little is known about the role of epigenetics in the differentiation of a bacterium from the free-living to the symbiotic state. Here genome-wide analysis of DNA methylation changes between these states is described using the model of symbiosis between soybean and its root nodule-forming, nitrogen-fixing symbiont, Bradyrhizobium diazoefficiens. PacBio resequencing of the B. diazoefficiens genome from both states revealed 43,061 sites recognized by five motifs with the potential to be methylated genome-wide. Of those sites, 3276 changed methylation states in 2921 genes or 35.5% of all genes in the genome. Over 10% of the methylation changes occurred within the symbiosis island that comprises 7.4% of the genome. The CCTTGAG motif was methylated only during symbiosis with 1361 adenosines methylated among the 1700 possible sites. Another 89 genes within the symbiotic island and 768 genes throughout the genome were found to have methylation and significant expression changes during symbiotic development. Of those, nine known symbiosis genes involved in all phases of symbiotic development including early infection events, nodule development, and nitrogenase production. These associations between methylation and expression changes in many B. diazoefficiens genes suggest an important role of the epigenome in bacterial differentiation to the symbiotic state. PMID:27148207

  7. Plant potassium content modifies the effects of arbuscular mycorrhizal symbiosis on root hydraulic properties in maize plants.

    PubMed

    El-Mesbahi, Mohamed Najib; Azcón, Rosario; Ruiz-Lozano, Juan Manuel; Aroca, Ricardo

    2012-10-01

    It is well known that the arbuscular mycorrhizal (AM) symbiosis helps the host plant to overcome several abiotic stresses including drought. One of the mechanisms for this drought tolerance enhancement is the higher water uptake capacity of the mycorrhizal plants. However, the effects of the AM symbiosis on processes regulating root hydraulic properties of the host plant, such as root hydraulic conductivity and plasma membrane aquaporin gene expression, and protein abundance, are not well defined. Since it is known that K(+) status is modified by AM and that it regulates root hydraulic properties, it has been tested how plant K(+) status could modify the effects of the symbiosis on root hydraulic conductivity and plasma membrane aquaporin gene expression and protein abundance, using maize (Zea mays L.) plants and Glomus intraradices as a model. It was observed that the supply of extra K(+) increased root hydraulic conductivity only in AM plants. Also, the different pattern of plasma membrane aquaporin gene expression and protein abundance between AM and non-AM plants changed with the application of extra K(+). Thus, plant K(+) status could be one of the causes of the different observed effects of the AM symbiosis on root hydraulic properties. The present study also highlights the critical importance of AM fungal aquaporins in regulating root hydraulic properties of the host plant. PMID:22370879

  8. Knowing your friends and foes--plant receptor-like kinases as initiators of symbiosis or defence.

    PubMed

    Antolín-Llovera, Meritxell; Petutsching, Elena Kristin; Ried, Martina Katharina; Lipka, Volker; Nürnberger, Thorsten; Robatzek, Silke; Parniske, Martin

    2014-12-01

    The decision between defence and symbiosis signalling in plants involves alternative and modular plasma membrane-localized receptor complexes. A critical step in their activation is ligand-induced homo- or hetero-oligomerization of leucine-rich repeat (LRR)- and/or lysin motif (LysM) receptor-like kinases (RLKs). In defence signalling, receptor complexes form upon binding of pathogen-associated molecular patterns (PAMPs), including the bacterial flagellin-derived peptide flg22, or chitin. Similar mechanisms are likely to operate during the perception of microbial symbiont-derived (lipo)-chitooligosaccharides. The structurally related chitin-oligomer ligands chitooctaose and chitotetraose trigger defence and symbiosis signalling, respectively, and their discrimination involves closely related, if not identical, LysM-RLKs. This illustrates the demand for and the challenges imposed on decision mechanisms that ensure appropriate signal initiation. Appropriate signalling critically depends on abundance and localization of RLKs at the cell surface. This is regulated by internalization, which also provides a mechanism for the removal of activated signalling RLKs. Abundance of the malectin-like domain (MLD)-LRR-RLK Symbiosis Receptor-like Kinase (SYMRK) is additionally controlled by cleavage of its modular ectodomain, which generates a truncated and rapidly degraded RLK fragment. This review explores LRR- and LysM-mediated signalling, the involvement of MLD-LRR-RLKs in symbiosis and defence, and the role of endocytosis in RLK function.

  9. Arbuscular mycorrhizal symbiosis can mitigate the negative effects of night warming on physiological traits of Medicago truncatula L.

    PubMed

    Hu, Yajun; Wu, Songlin; Sun, Yuqing; Li, Tao; Zhang, Xin; Chen, Caiyan; Lin, Ge; Chen, Baodong

    2015-02-01

    Elevated night temperature, one of the main climate warming scenarios, can have profound effects on plant growth and metabolism. However, little attention has been paid to the potential role of mycorrhizal associations in plant responses to night warming, although it is well known that symbiotic fungi can protect host plants against various environmental stresses. In the present study, physiological traits of Medicago truncatula L. in association with the arbuscular mycorrhizal (AM) fungus Rhizophagus irregularis were investigated under simulated night warming. A constant increase in night temperature of 1.53 °C significantly reduced plant shoot and root biomass, flower and seed number, leaf sugar concentration, and shoot Zn and root P concentrations. However, the AM association essentially mitigated these negative effects of night warming by improving plant growth, especially through increased root biomass, root to shoot ratio, and shoot Zn and root P concentrations. A significant interaction was observed between R. irregularis inoculation and night warming in influencing both root sucrose concentration and expression of sucrose synthase (SusS) genes, suggesting that AM symbiosis and increased night temperature jointly regulated plant sugar metabolism. Night warming stimulated AM fungal colonization but did not influence arbuscule abundance, symbiosis-related plant or fungal gene expression, or growth of extraradical mycelium, indicating little effect of night warming on the development or functioning of AM symbiosis. These findings highlight the importance of mycorrhizal symbiosis in assisting plant resilience to climate warming.

  10. Arbuscular mycorrhizal symbiosis alters stomatal conductance of host plants more under drought than under amply watered conditions: a meta-analysis.

    PubMed

    Augé, Robert M; Toler, Heather D; Saxton, Arnold M

    2015-01-01

    Stomata regulate rates of carbon assimilation and water loss. Arbuscular mycorrhizal (AM) symbioses often modify stomatal behavior and therefore play pivotal roles in plant productivity. The size of the AM effect on stomatal conductance to water vapor (g s ) has varied widely, has not always been apparent, and is unpredictable. We conducted a meta-analysis of 460 studies to determine the size of the AM effect under ample watering and drought and to examine how experimental conditions have influenced the AM effect. Across all host and symbiont combinations under all soil moisture conditions, AM plants have shown 24 % higher g s than nonmycorrhizal (NM) controls. The promotion of g s has been over twice as great during moderate drought than under amply watered conditions. The AM influence on g s has been even more pronounced under severe drought, with over four times the promotion observed with ample water. Members of the Claroideoglomeraceae, Glomeraceae, and other AM families stimulated g s by about the same average amount. Colonization by native AM fungi has produced the largest promotion. Among single-AM symbionts, Glomus deserticola, Claroideoglomus etunicatum, and Funneliformis mosseae have had the largest average effects on g s across studies. Dicotyledonous hosts, especially legumes, have been slightly more responsive to AM symbiosis than monocotyledonous hosts, and C3 plants have shown over twice the AM-induced promotion of C4 plants. The extent of root colonization is important, with heavily colonized plants showing ×10 the g s promotion of lightly colonized plants. AM promotion of g s has been larger in growth chambers and in the field than in greenhouse studies, almost ×3 as large when plants were grown under high light than low light, and ×2.5 as large in purely mineral soils than in soils having an organic component. When AM plants have been compared with NM controls given NM pot culture, they have shown only half the promotion of g s as NM plants

  11. Tsetse-Wolbachia symbiosis: comes of age and has great potential for pest and disease control.

    PubMed

    Doudoumis, Vangelis; Alam, Uzma; Aksoy, Emre; Abd-Alla, Adly M M; Tsiamis, George; Brelsfoard, Corey; Aksoy, Serap; Bourtzis, Kostas

    2013-03-01

    Tsetse flies (Diptera: Glossinidae) are the sole vectors of African trypanosomes, the causative agent of sleeping sickness in human and nagana in animals. Like most eukaryotic organisms, Glossina species have established symbiotic associations with bacteria. Three main symbiotic bacteria have been found in tsetse flies: Wigglesworthia glossinidia, an obligate symbiotic bacterium, the secondary endosymbiont Sodalis glossinidius and the reproductive symbiont Wolbachia pipientis. In the present review, we discuss recent studies on the detection and characterization of Wolbachia infections in Glossina species, the horizontal transfer of Wolbachia genes to tsetse chromosomes, the ability of this symbiont to induce cytoplasmic incompatibility in Glossina morsitans morsitans and also how new environment-friendly tools for disease control could be developed by harnessing Wolbachia symbiosis.

  12. Symbiont recruitment versus ant-symbiont co-evolution in the attine ant-microbe symbiosis.

    PubMed

    Mueller, Ulrich G

    2012-06-01

    The symbiosis between fungus-farming ants (Attini, Formicidae), their cultivated fungi, garden-infecting Escovopsis pathogens, and Pseudonocardia bacteria on the ant integument has been popularized as an example of ant-Escovopsis-Pseudonocardia co-evolution. Recent research could not verify earlier conclusions regarding antibiotic-secreting, integumental Pseudonocardia that co-evolve to specifically suppress Escovopsis disease in an ancient co-evolutionary arms-race. Rather than long-term association with a single, co-evolving Pseudonocardia strain, attine ants accumulate complex, dynamic biofilms on their integument and in their gardens. Emerging views are that the integumental biofilms protect the ants primarily against ant diseases, whereas garden biofilms protect primarily against garden diseases; attine ants selectively recruit ('screen in') microbes into their biofilms; and the biofilms of ants and gardens serve diverse functions beyond disease-suppression.

  13. Developmental Plasticity and Developmental Symbiosis: The Return of Eco-Devo.

    PubMed

    Gilbert, Scott F

    2016-01-01

    Ecological developmental biology is the study of the interactions between developing organisms and their environments. Organisms have evolved to use the environment as a source of important cues that can alter the trajectory of their development. First, developmental plasticity enables the genome to generate a repertoire of possible phenotypes, and environmental cues are often used to select the phenotype that appears most adaptive at that time. This facilitates evolutionary strategies such as phenotypic accommodation, genetic assimilation, and niche construction. Second, developmental symbiosis, wherein the developing animal utilizes cues from other organisms for normal cell differentiation and morphogenesis, has been found to be ubiquitous. The coevolution of symbiotic microbes and animal cells has often led to the dependency of an animal's development on particular microbial signals, making these cues essential and expected components of normal development.

  14. [Effects of the symbiosis of Trichomonas vaginalis with Mycoplasma hominis on ferredoxin gene].

    PubMed

    Liu, Xiaodong; Wen, Wenjing; Xue, Changgui

    2011-08-01

    We isolated 30 Trichomonas vaginalis for the PCR detection from the gynecological outpatients in the Affiliated Hospital of Zhengzhou University using the specific 16s rDNA primers of Mycoplasma hominis. The results showed that there were 25 cases of Mycoplasma hominis infection, with the infection rate of 83.33%. This gave a clew that the symbiosis of Trichomonas vaginalis with Mycoplasma hominis may be of certain generality in China. We sequenced the ferredoxin gene of 10 Trichomonas vaginalis where 5 Mycoplasma hominis were positive and five negative, and found that the ferredoxin (Fd) gene of the 10 Trichomonas vaginalis were exactly the same. But compared to the genes in the GenBank, a comparative analysis of the gene revealed that there were 3 more ctg bases at the 200th position of encoding leucine, but this did not lead to changes in reading frame. The gene homology was 99%.

  15. Evolution of symbiosis in the Vibrionaceae: a combined approach using molecules and physiology.

    PubMed

    Nishiguchi, Michele K; Nair, Vinod S

    2003-11-01

    The family Vibrionaceae is considered to be one of the most diverse and well-studied groups of bacteria. Here, evolution is assessed within the Vibrionaceae to determine whether multiple origins of eukaryotic associations have occurred within this diverse group of bacteria. Analyses were based on a large molecular dataset, along with a matrix that consisted of 100 biochemical and restriction digest characters. By using direct optimization methods to analyse both datasets individually and in combination, a total-evidence cladogram has been produced, which supports the hypothesis that several important symbionts (both mutualistic and pathogenic) within the Vibrionaceae are not monophyletic. This leads us to consider that symbiosis (and subsequently, associations with Eukarya) has evolved multiple times within the Vibrionaceae lineage.

  16. The nested structure of marine cleaning symbiosis: is it like flowers and bees?

    PubMed

    Guimarães, Paulo R; Sazima, Cristina; dos Reis, Sérgio Furtado; Sazima, Ivan

    2007-02-22

    In a given area, plant-animal mutualistic interactions form complex networks that often display nestedness, a particular type of asymmetry in interactions. Simple ecological and evolutionary factors have been hypothesized to lead to nested networks. Therefore, nestedness is expected to occur in other types of mutualisms as well. We tested the above prediction with the network structure of interactions in cleaning symbiosis at three reef assemblages. In this type of interaction, shrimps and fishes forage on ectoparasites and injured tissues from the body surface of fish species. Cleaning networks show strong patterns of nestedness. In fact, after controlling for species richness, cleaning networks are even more nested than plant-animal mutualisms. Our results support the notion that mutualisms evolve to a predictable community-level structure, be it in terrestrial or marine communities.

  17. Man-robot symbiosis: a framework for cooperative intelligence and control

    SciTech Connect

    Parker, L.E.; Pin, F.G.

    1988-01-01

    The man-robot symbiosis concept has the fundamental objective of bridging the gap between fully human-controlled and fully autonomous systems to achieve true man-robot cooperative control and intelligence. Such a system would allow improved speed, accuracy, and efficiency of task execution, while retaining the man in the loop for innovative reasoning and decision-making. The symbiont would have capabilities for supervised and unsupervised learning, allowing an increase of expertise in a wide task domain. This paper describes a robotic system architecture facilitating the symbiotic integration of teleoperative and automated modes of task execution. The architecture reflects a unique blend of many disciplines of artificial intelligence into a working system, including job or monitoring, and machine learning. These disciplines are embodied in five major components of the symbiotic framework: the Job Planner, the Dynamic Task Allocator, the Presenter/Interpreter, the Automated Monitor, and the Learning System. 12 refs., 3 figs.

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

    PubMed

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

    2015-01-01

    Screening of nodule bacteria (rhizobia) forming symbiotic relationships with legumes has been performed in order to isolate strains resistant to cadmium ions in a wide range of concentrations (6-132 mg/kg). The effect ofcadmium salts (6, 12, 24 mg/kg) on the legume-rhizobium symbiosis ofthe pea Pisum sativum L. with Rhizobium leguminosarum and of the fodder galega Galega orientalis Lam. with Rhizobium galegae has been studied under experimental laboratory conditions. No statistically significant differences have been revealed in the growth and biomass of plants with regard to the control in the range of concentrations given above. However, it was found that cadmium inhibited nodulation in P. sativum and stimulated it in G. orientalis. PMID:26638242

  19. Mycosporine-like amino acids in the zooxanthella-ciliate symbiosis Maristentor dinoferus.

    PubMed

    Sommaruga, Ruben; Whitehead, Kenia; Shick, J Malcolm; Lobban, Christopher S

    2006-06-01

    Coral reef organisms living in mutualistic symbioses with phototrophic dinoflagellates are widespread in shallow UV-transparent waters. Maristentor dinoferus is a recently discovered species of marine benthic ciliate that hosts symbiotic dinoflagellates of the genus Symbiodinium. In this study, we tested this ciliate for the occurrence of mycosporine-like amino acids, a family of secondary metabolites that minimize damage from exposure to solar UV radiation by direct screening. Using high-performance liquid chromatography and liquid chromatography coupled to mass spectrometry, five mycosporine-like amino acids (shinorine, palythenic acid, palythine, mycosporine-2-glycine, and porphyra-334) were identified in aqueous methanolic extracts of the symbiosis. This is the first report of mycosporine-like amino acids in a marine ciliate. PMID:16621697

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

    PubMed

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

    2015-01-01

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

  1. Arbuscular mycorrhizal symbiosis affects the grain proteome of Zea mays: a field study

    PubMed Central

    Bona, Elisa; Scarafoni, Alessio; Marsano, Francesco; Boatti, Lara; Copetta, Andrea; Massa, Nadia; Gamalero, Elisa; D’Agostino, Giovanni; Cesaro, Patrizia; Cavaletto, Maria; Berta, Graziella

    2016-01-01

    Maize is one of the most important crops worldwide and is strongly dependent on arbuscular mycorrhiza (AM) fungi, organisms that form a mutualistic association with land plants. In maize, AM symbiosis enhances spike dry weight, spike length, spike circumference, and the dry weight and dimensions of the grain. Notwithstanding its ubiquitous nature, the detailed relationship between AM fungal colonization and plant development is not completely understood. To facilitate a better understanding of the effects of AM fungi on plants, the work reported here assessed the effects of a consortium of AM fungi on the kernel proteome of maize, cultivated in open-field conditions. To our knowledge, this is the first report of the modulation of a plant seed proteome following AM fungal inoculation in the field. Here, it was found that AM fungi modify the maize seed proteome by up-regulating enzymes involved in energetic metabolism, embryo development, nucleotide metabolism, seed storage and stress responses. PMID:27216714

  2. Some aspects of optimal human-computer symbiosis in multisensor geospatial data fusion

    NASA Astrophysics Data System (ADS)

    Levin, E.; Sergeyev, A.

    Nowadays vast amount of the available geospatial data provides additional opportunities for the targeting accuracy increase due to possibility of geospatial data fusion. One of the most obvious operations is determining of the targets 3D shapes and geospatial positions based on overlapped 2D imagery and sensor modeling. 3D models allows for the extraction of such information about targets, which cannot be measured directly based on single non-fused imagery. Paper describes ongoing research effort at Michigan Tech attempting to combine advantages of human analysts and computer automated processing for efficient human computer symbiosis for geospatial data fusion. Specifically, capabilities provided by integration into geospatial targeting interfaces novel human-computer interaction method such as eye-tracking and EEG was explored. Paper describes research performed and results in more details.

  3. Interaction between host genotype and environmental conditions affects bacterial density in Wolbachia symbiosis.

    PubMed

    Mouton, Laurence; Henri, Hélène; Charif, Delphine; Boulétreau, Michel; Vavre, Fabrice

    2007-04-22

    Regulation of microbial population density is a necessity in stable symbiotic interactions. In Wolbachia symbiosis, both bacterial and host genotypes are involved in density regulation, but environmental factors may also affect bacterial population density. Here, we studied the interaction between three strains of Wolbachia in two divergent homozygous lines of the wasp Leptopilina heterotoma at two different temperatures. Wolbachia density varied between the two host genotypes at only one temperature. Moreover, at this temperature, reciprocal-cross F1 insects displayed identical Wolbachia densities, which were intermediate between the densities in the two parental lines. While these findings confirm that the host genotype plays an important role in Wolbachia density, they also highlight its interaction with environmental conditions, making possible the evolution of local adaptations for the regulation of Wolbachia density. PMID:17251124

  4. Evolutionarily conserved CLE peptide signaling in plant development, symbiosis, and parasitism.

    PubMed

    Miyawaki, Kaori; Tabata, Ryo; Sawa, Shinichiro

    2013-10-01

    Small polypeptides are widely used as signaling molecules in cell-to-cell communication in animals and plants. The CLAVATA3/EMBRYO SURROUNDING REGION-RELATED (CLE) gene family is composed of numerous genes that contain conserved CLE domains in various plant species and plant-parasitic nematodes. Here, we review recent progress in our understanding of CLE signaling during stem cell maintenance in Arabidopsis and grasses. We also summarize the roles of CLE signaling in the legume-Rhizobium symbiosis and infection by plant-parasitic nematodes. CLE signaling is important for diverse aspects of cell-to-cell signaling and long-distance communication, which are critical for survival, and the basic components of the CLE signaling pathway are evolutionarily conserved in both plants and animals.

  5. 7 CFR 1208.20 - Promotion.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PROCESSED RASPBERRY PROMOTION, RESEARCH, AND INFORMATION ORDER Processed Raspberry Promotion, Research, and Information Order Definitions... raspberries to the general public and the food industry for the purpose of improving the competitive...

  6. 7 CFR 1208.20 - Promotion.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE PROCESSED RASPBERRY PROMOTION, RESEARCH, AND INFORMATION ORDER Processed Raspberry Promotion, Research, and Information Order Definitions... raspberries to the general public and the food industry for the purpose of improving the competitive...

  7. 7 CFR 1212.20 - Promotion.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE HONEY PACKERS AND IMPORTERS RESEARCH, PROMOTION, CONSUMER EDUCATION AND INDUSTRY INFORMATION ORDER Honey Packers and Importers Research, Promotion... action, including paid advertising and public relations that presents a favorable image for honey...

  8. 7 CFR 1212.20 - Promotion.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE HONEY PACKERS AND IMPORTERS RESEARCH, PROMOTION, CONSUMER EDUCATION AND INDUSTRY INFORMATION ORDER Honey Packers and Importers Research, Promotion... action, including paid advertising and public relations that presents a favorable image for honey...

  9. 7 CFR 1212.20 - Promotion.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE HONEY PACKERS AND IMPORTERS RESEARCH, PROMOTION, CONSUMER EDUCATION AND INDUSTRY INFORMATION ORDER Honey Packers and Importers Research, Promotion... action, including paid advertising and public relations that presents a favorable image for honey...

  10. 7 CFR 1212.20 - Promotion.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE HONEY PACKERS AND IMPORTERS RESEARCH, PROMOTION, CONSUMER EDUCATION AND INDUSTRY INFORMATION ORDER Honey Packers and Importers Research, Promotion... action, including paid advertising and public relations that presents a favorable image for honey...

  11. Effector-Triggered Immunity Determines Host Genotype-Specific Incompatibility in Legume-Rhizobium Symbiosis.

    PubMed

    Yasuda, Michiko; Miwa, Hiroki; Masuda, Sachiko; Takebayashi, Yumiko; Sakakibara, Hitoshi; Okazaki, Shin

    2016-08-01

    Symbiosis between legumes and rhizobia leads to the formation of N2-fixing root nodules. In soybean, several host genes, referred to as Rj genes, control nodulation. Soybean cultivars carrying the Rj4 gene restrict nodulation by specific rhizobia such as Bradyrhizobium elkanii We previously reported that the restriction of nodulation was caused by B. elkanii possessing a functional type III secretion system (T3SS), which is known for its delivery of virulence factors by pathogenic bacteria. In the present study, we investigated the molecular basis for the T3SS-dependent nodulation restriction in Rj4 soybean. Inoculation tests revealed that soybean cultivar BARC-2 (Rj4/Rj4) restricted nodulation by B. elkanii USDA61, whereas its nearly isogenic line BARC-3 (rj4/rj4) formed nitrogen-fixing nodules with the same strain. Root-hair curling and infection threads were not observed in the roots of BARC-2 inoculated with USDA61, indicating that Rj4 blocked B. elkanii infection in the early stages. Accumulation of H2O2 and salicylic acid (SA) was observed in the roots of BARC-2 inoculated with USDA61. Transcriptome analyses revealed that inoculation of USDA61, but not its T3SS mutant in BARC-2, induced defense-related genes, including those coding for hypersensitive-induced responsive protein, which act in effector-triggered immunity (ETI) in Arabidopsis. These findings suggest that B. elkanii T3SS triggers the SA-mediated ETI-type response in Rj4 soybean, which consequently blocks symbiotic interactions. This study revealed a common molecular mechanism underlying both plant-pathogen and plant-symbiont interactions, and suggests that establishment of a root nodule symbiosis requires the evasion or suppression of plant immune responses triggered by rhizobial effectors. PMID:27373538

  12. Ultrastructural Characterization of the Prokaryotic Symbiosis in “Chlorochromatium aggregatum” ▿ †

    PubMed Central

    Wanner, Gerhard; Vogl, Kajetan; Overmann, Jörg

    2008-01-01

    The phototrophic consortium “Chlorochromatium aggregatum” currently represents the most highly developed interspecific association of bacteria and consists of green sulfur bacteria, so-called epibionts, surrounding a central, motile, chemotrophic bacterium. In order to identify subcellular structures characteristic of this symbiosis, consortia were studied by a combination of high-resolution analytical scanning electron microscopy, transmission electron microscopy, and three-dimensional reconstruction and image analyses. Epibionts are interconnected and to a lesser extent are also connected with the central bacterium, by electron-dense, hair-like filaments. In addition, numerous periplasmic tubules extend from the outer membrane of the central bacterium and are in direct contact with the outer membrane of the epibionts. In each epibiont cell, the attachment site to the central bacterium is characterized by the absence of chlorosomes and an additional 17-nm-thick layer (epibiont contact layer [ECL]) attached to the inner side of the cytoplasmic membrane. The ECL is only occasionally observed in pure cultures of the epibiont, where it occurs in about 10 to 20% of the free-living cells. A striking feature of the central bacterium is the presence of one or two hexagonally packed flat crystals (central bacterium crystal [CBC]) per cell. The CBC reaches 1 μm in length, is 35 nm thick, and consists of bilayers of subunits with a spacing of 9 nm. A detailed model for consortia is presented, summarizing our conclusions regarding (i) cohesion of the cells, (ii) common periplasmic space between the central bacterium and the epibiont, (iii) ECL as a symbiosis-specific structure, and (iv) formation of the interior paracrystalline structures, central bacterium membrane layer, and CBC. PMID:18344357

  13. Rhizobiales as functional and endosymbiontic members in the lichen symbiosis of Lobaria pulmonaria L.

    PubMed

    Erlacher, Armin; Cernava, Tomislav; Cardinale, Massimiliano; Soh, Jung; Sensen, Christoph W; Grube, Martin; Berg, Gabriele

    2015-01-01

    Rhizobiales (Alphaproteobacteria) are well-known beneficial partners in plant-microbe interactions. Less is known about the occurrence and function of Rhizobiales in the lichen symbiosis, although it has previously been shown that Alphaproteobacteria are the dominating group in growing lichen thalli. We have analyzed the taxonomic structure and assigned functions to Rhizobiales within a metagenomic dataset of the lung lichen Lobaria pulmonaria L. One third (32.2%) of the overall bacteria belong to the Rhizobiales, in particular to the families Methylobacteriaceae, Bradyrhizobiaceae, and Rhizobiaceae. About 20% of our metagenomic assignments could not be placed in any of the Rhizobiales lineages, which indicates a yet undescribed bacterial diversity. SEED-based functional analysis focused on Rhizobiales and revealed functions supporting the symbiosis, including auxin and vitamin production, nitrogen fixation and stress protection. We also have used a specifically developed probe to localize Rhizobiales by confocal laser scanning microscopy after fluorescence in situ hybridization (FISH-CLSM). Bacteria preferentially colonized fungal surfaces, but there is clear evidence that members of the Rhizobiales are able to intrude at varying depths into the interhyphal gelatinous matrix of the upper lichen cortical layer and that at least occasionally some bacteria also are capable to colonize the interior of the fungal hyphae. Interestingly, the gradual development of an endosymbiotic bacterial life was found for lichen- as well as for fungal- and plant-associated bacteria. The new tools to study Rhizobiales, FISH microscopy and comparative metagenomics, suggest a similar beneficial role for lichens than for plants and will help to better understand the Rhizobiales-host interaction and their biotechnological potential. PMID:25713563

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

    PubMed Central

    Tóth, Katalin; Stacey, Gary

    2015-01-01

    Plants are exposed to many different microbes in their habitats. These microbes may be benign or pathogenic, but in some cases they are beneficial for the host. The rhizosphere provides an especially rich palette for colonization by beneficial (associative and symbiotic) microorganisms, which raises the question as to how roots can distinguish such ‘friends’ from possible ‘foes’ (i.e., pathogens). Plants possess an innate immune system that can recognize pathogens, through an arsenal of protein receptors, including receptor-like kinases (RLKs) and receptor-like proteins (RLPs) located at the plasma membrane. In addition, the plant host has intracellular receptors (so called NBS-LRR proteins or R proteins) that directly or indirectly recognize molecules released by microbes into the plant cell. A successful cooperation between legume plants and rhizobia leads to beneficial symbiotic interaction. The key rhizobial, symbiotic signaling molecules [lipo-chitooligosaccharide Nod factors (NF)] are perceived by the host legume plant using lysin motif-domain containing RLKs. Perception of the symbiotic NFs trigger signaling cascades leading to bacterial infection and accommodation of the symbiont in a newly formed root organ, the nodule, resulting in a nitrogen-fixing root nodule symbiosis. The net result of this symbiosis is the intracellular colonization of the plant with thousands of bacteria; a process that seems to occur in spite of the immune ability of plants to prevent pathogen infection. In this review, we discuss the potential of the invading rhizobial symbiont to actively avoid this innate immune response, as well as specific examples of where the plant immune response may modulate rhizobial infection and host range. PMID:26082790

  15. Small-peptide signals that control root nodule number, development, and symbiosis.

    PubMed

    Djordjevic, Michael A; Mohd-Radzman, Nadiatul A; Imin, Nijat

    2015-08-01

    Many legumes have the capacity to enter into a symbiotic association with soil bacteria generically called 'rhizobia' that results in the formation of new lateral organs on roots called nodules within which the rhizobia fix atmospheric nitrogen (N). Up to 200 million tonnes of N per annum is fixed by this association. Therefore, this symbiosis plays an integral role in the N cycle and is exploited in agriculture to support the sustainable fixation of N for cropping and animal production in developing and developed nations. Root nodulation is an expendable developmental process and competency for nodulation is coupled to low-N conditions. Both nodule initiation and development is suppressed under high-N conditions. Although root nodule formation enables sufficient N to be fixed for legumes to grow under N-deficient conditions, the carbon cost is high and nodule number is tightly regulated by local and systemic mechanisms. How legumes co-ordinate nodule formation with the other main organs of nutrient acquisition, lateral roots, is not fully understood. Independent mechanisms appear to regulate lateral roots and nodules under low- and high-N regimes. Recently, several signalling peptides have been implicated in the local and systemic regulation of nodule and lateral root formation. Other peptide classes control the symbiotic interaction of rhizobia with the host. This review focuses on the roles played by signalling peptides during the early stages of root nodule formation, in the control of nodule number, and in the establishment of symbiosis. Here, we highlight the latest findings and the gaps in our understanding of these processes.

  16. Nitric Oxide Mediates Biofilm Formation and Symbiosis in Silicibacter sp. Strain TrichCH4B

    PubMed Central

    Rao, Minxi; Smith, Brian C.

    2015-01-01

    ABSTRACT Nitric oxide (NO) plays an important signaling role in all domains of life. Many bacteria contain a heme-nitric oxide/oxygen binding (H-NOX) protein that selectively binds NO. These H-NOX proteins often act as sensors that regulate histidine kinase (HK) activity, forming part of a bacterial two-component signaling system that also involves one or more response regulators. In several organisms, NO binding to the H-NOX protein governs bacterial biofilm formation; however, the source of NO exposure for these bacteria is unknown. In mammals, NO is generated by the enzyme nitric oxide synthase (NOS) and signals through binding the H-NOX domain of soluble guanylate cyclase. Recently, several bacterial NOS proteins have also been reported, but the corresponding bacteria do not also encode an H-NOX protein. Here, we report the first characterization of a bacterium that encodes both a NOS and H-NOX, thus resembling the mammalian system capable of both synthesizing and sensing NO. We characterized the NO signaling pathway of the marine alphaproteobacterium Silicibacter sp. strain TrichCH4B, determining that the NOS is activated by an algal symbiont, Trichodesmium erythraeum. NO signaling through a histidine kinase-response regulator two-component signaling pathway results in increased concentrations of cyclic diguanosine monophosphate, a key bacterial second messenger molecule that controls cellular adhesion and biofilm formation. Silicibacter sp. TrichCH4B biofilm formation, activated by T. erythraeum, may be an important mechanism for symbiosis between the two organisms, revealing that NO plays a previously unknown key role in bacterial communication and symbiosis. PMID:25944856

  17. Evidence of an American Origin for Symbiosis-Related Genes in Rhizobium lusitanum ▿

    PubMed Central

    Valverde, Angel; Velázquez, Encarna; Cervantes, Emilio; Igual, José M.; van Berkum, Peter

    2011-01-01

    Randomly amplified polymorphic DNA (RAPD) analysis was used to investigate the diversity of 179 bean isolates recovered from six field sites in the Arcos de Valdevez region of northwestern Portugal. The isolates were divided into 6 groups based on the fingerprint patterns that were obtained. Representatives for each group were selected for sequence analysis of 4 chromosomal DNA regions. Five of the groups were placed within Rhizobium lusitanum, and the other group was placed within R. tropici type IIA. Therefore, the collection of Portuguese bean isolates was shown to include the two species R. lusitanum and R. tropici. In plant tests, the strains P1-7, P1-1, P1-2, and P1-16 of R. lusitanum nodulated and formed nitrogen-fixing symbioses both with Phaseolus vulgaris and Leucaena leucocephala. A methyltransferase-encoding nodS gene identical with the R. tropici locus that confers wide host range was detected in the strain P1-7 as well as 24 others identified as R. lusitanum. A methyltransferase-encoding nodS gene also was detected in the remaining isolates of R. lusitanum, but in this case the locus was that identified with the narrow-host-range R. etli. Representatives of isolates with the nodS of R. etli formed effective nitrogen-fixing symbioses with P. vulgaris and did not nodulate L. leucocephala. From sequence data of nodS, the R. lusitanum genes for symbiosis were placed within those of either R. tropici or R. etli. These results would support the suggestion that R. lusitanum was the recipient of the genes for symbiosis with beans from both R. tropici and R. etli. PMID:21705533

  18. The ambrosia symbiosis is specific in some species and promiscuous in others: evidence from community pyrosequencing

    PubMed Central

    Kostovcik, Martin; Bateman, Craig C; Kolarik, Miroslav; Stelinski, Lukasz L; Jordal, Bjarte H; Hulcr, Jiri

    2015-01-01

    Symbioses are increasingly seen as dynamic ecosystems with multiple associates and varying fidelity. Symbiont specificity remains elusive in one of the most ecologically successful and economically damaging eukaryotic symbioses: the ambrosia symbiosis of wood-boring beetles and fungi. We used multiplexed pyrosequencing of amplified internal transcribed spacer II (ITS2) ribosomal DNA (rDNA) libraries to document the communities of fungal associates and symbionts inside the mycangia (fungus transfer organ) of three ambrosia beetle species, Xyleborus affinis, Xyleborus ferrugineus and Xylosandrus crassiusculus. We processed 93 beetle samples from 5 locations across Florida, including reference communities. Fungal communities within mycangia included 14–20 fungus species, many more than reported by culture-based studies. We recovered previously known nutritional symbionts as members of the core community. We also detected several other fungal taxa that are equally frequent but whose function is unknown and many other transient species. The composition of fungal assemblages was significantly correlated with beetle species but not with locality. The type of mycangium appears to determine specificity: two Xyleborus with mandibular mycangia had multiple dominant associates with even abundances; Xylosandrus crassiusculus (mesonotal mycangium) communities were dominated by a single symbiont, Ambrosiella sp. Beetle mycangia also carried many fungi from the environment, including plant pathogens and endophytes. The ITS2 marker proved useful for ecological analyses, but the taxonomic resolution was limited to fungal genus or family, particularly in Ophiostomatales, which are under-represented in our amplicons as well as in public databases. This initial analysis of three beetle species suggests that each clade of ambrosia beetles and each mycangium type may support a functionally and taxonomically distinct symbiosis. PMID:25083930

  19. Evolution of the tripartite symbiosis between earthworms, Verminephrobacter and Flexibacter-like bacteria

    PubMed Central

    Møller, Peter; Lund, Marie B.; Schramm, Andreas

    2015-01-01

    Nephridial (excretory organ) symbionts are widespread in lumbricid earthworms and the complexity of the nephridial symbiont communities varies greatly between earthworm species. The two most common symbionts are the well-described Verminephrobacter and less well-known Flexibacter-like bacteria. Verminephrobacter are present in almost all lumbricid earthworms, they are species-specific, vertically transmitted, and have presumably been associated with their hosts since the origin of lumbricids. Flexibacter-like symbionts have been reported from about half the investigated earthworms; they are also vertically transmitted. To investigate the evolution of this tri-partite symbiosis, phylogenies for 18 lumbricid earthworm species were constructed based on two mitochondrial genes, NADH dehydrogenase subunit 2 (ND2) and cytochrome c oxidase subunit I (COI), and compared to their symbiont phylogenies based on RNA polymerase subunit B (rpoB) and 16S rRNA genes. The two nephridial symbionts showed markedly different evolutionary histories with their hosts. For Verminephrobacter, clear signs of long-term host-symbiont co-evolution with rare host switching events confirmed its ancient association with lumbricid earthworms, likely dating back to their last common ancestor about 100 million years (MY) ago. In contrast, phylogenies for the Flexibacter-like symbionts suggested an ability to switch to new hosts, to which they adapted and subsequently became species-specific. Putative co-speciation events were only observed with closely related host species; on that basis, this secondary symbiosis was estimated to be minimum 45 MY old. Based on the monophyletic clustering of the Flexibacter-like symbionts, the low 16S rRNA gene sequence similarity to the nearest described species (<92%) and environmental sequences (<94.2%), and the specific habitat in the earthworm nephridia, we propose a new candidate genus for this group, Candidatus Nephrothrix. PMID:26074907

  20. Artificial symbiosis for acetone-butanol-ethanol (ABE) fermentation from alkali extracted deshelled corn cobs by co-culture of Clostridium beijerinckii and Clostridium cellulovorans

    PubMed Central

    2014-01-01

    Background Butanol is an industrial commodity and also considered to be a more promising gasoline substitute compared to ethanol. Renewed attention has been paid to solvents (acetone, butanol and ethanol) production from the renewable and inexpensive substrates, for example, lignocellulose, on account of the depletion of oil resources, increasing gasoline prices and deteriorating environment. Limited to current tools for genetic manipulation, it is difficult to develop a genetically engineered microorganism with combined ability of lignocellulose utilization and solvents production. Mixed culture of cellulolytic microorganisms and solventogenic bacteria provides a more convenient and feasible approach for ABE fermentation due to the potential for synergistic utilization of the metabolic pathways of two organisms. But few bacteria pairs succeeded in producing biobutanol of high titer or high productivity without adding butyrate. The aim of this work was to use Clostridium cellulovorans 743B to saccharify lignocellulose and produce butyric acid, instead of adding cellulase and butyric acid to the medium, so that the soluble sugars and butyric acid generated can be subsequently utilized by Clostridium beijerinckii NCIMB 8052 to produce butanol in one pot reaction. Results A stable artificial symbiotic system was constructed by co-culturing a celluloytic, anaerobic, butyrate-producing mesophile (C. cellulovorans 743B) and a non-celluloytic, solventogenic bacterium (C. beijerinckii NCIMB 8052) to produce solvents by consolidated bioprocessing (CBP) with alkali extracted deshelled corn cobs (AECC), a low-cost renewable feedstock, as the sole carbon source. Under optimized conditions, the co-culture degraded 68.6 g/L AECC and produced 11.8 g/L solvents (2.64 g/L acetone, 8.30 g/L butanol and 0.87 g/L ethanol) in less than 80 h. Besides, a real-time PCR assay based on the 16S rRNA gene sequence was performed to study the dynamics of the abundance of each strain

  1. Novel Root-Fungus Symbiosis in Ericaceae: Sheathed Ericoid Mycorrhiza Formed by a Hitherto Undescribed Basidiomycete with Affinities to Trechisporales

    PubMed Central

    Vohník, Martin; Sadowsky, Jesse J.; Kohout, Petr; Lhotáková, Zuzana; Nestby, Rolf; Kolařík, Miroslav

    2012-01-01

    Ericaceae (the heath family) are widely distributed calcifuges inhabiting soils with inherently poor nutrient status. Ericaceae overcome nutrient limitation through symbiosis with ericoid mycorrhizal (ErM) fungi that mobilize nutrients complexed in recalcitrant organic matter. At present, recognized ErM fungi include a narrow taxonomic range within the Ascomycota, and the Sebacinales, basal Hymenomycetes with unclamped hyphae and imperforate parenthesomes. Here we describe a novel type of basidiomycetous ErM symbiosis, termed ‘sheathed ericoid mycorrhiza’, discovered in two habitats in mid-Norway as a co-dominant mycorrhizal symbiosis in Vaccinium spp. The basidiomycete forming sheathed ErM possesses clamped hyphae with perforate parenthesomes, produces 1- to 3-layer sheaths around terminal parts of hair roots and colonizes their rhizodermis intracellularly forming hyphal coils typical for ErM symbiosis. Two basidiomycetous isolates were obtained from sheathed ErM and molecular and phylogenetic tools were used to determine their identity; they were also examined for the ability to form sheathed ErM and lignocellulolytic potential. Surprisingly, ITS rDNA of both conspecific isolates failed to amplify with the most commonly used primer pairs, including ITS1 and ITS1F + ITS4. Phylogenetic analysis of nuclear LSU, SSU and 5.8S rDNA indicates that the basidiomycete occupies a long branch residing in the proximity of Trechisporales and Hymenochaetales, but lacks a clear sequence relationship (>90% similarity) to fungi currently placed in these orders. The basidiomycete formed the characteristic sheathed ErM symbiosis and enhanced growth of Vaccinium spp. in vitro, and degraded a recalcitrant aromatic substrate that was left unaltered by common ErM ascomycetes. Our findings provide coherent evidence that this hitherto undescribed basidiomycete forms a morphologically distinct ErM symbiosis that may occur at significant levels under natural conditions, yet remain

  2. Extracellular and Mixotrophic Symbiosis in the Whale-Fall Mussel Adipicola pacifica: A Trend in Evolution from Extra- to Intracellular Symbiosis

    PubMed Central

    Fujiwara, Yoshihiro; Kawato, Masaru; Noda, Chikayo; Kinoshita, Gin; Yamanaka, Toshiro; Fujita, Yuko; Uematsu, Katsuyuki; Miyazaki, Jun-Ichi

    2010-01-01

    Background Deep-sea mussels harboring chemoautotrophic symbionts from hydrothermal vents and seeps are assumed to have evolved from shallow-water asymbiotic relatives by way of biogenic reducing environments such as sunken wood and whale falls. Such symbiotic associations have been well characterized in mussels collected from vents, seeps and sunken wood but in only a few from whale falls. Methodology/Principal Finding Here we report symbioses in the gill tissues of two mussels, Adipicola crypta and Adipicola pacifica, collected from whale-falls on the continental shelf in the northwestern Pacific. The molecular, morphological and stable isotopic characteristics of bacterial symbionts were analyzed. A single phylotype of thioautotrophic bacteria was found in A. crypta gill tissue and two distinct phylotypes of bacteria (referred to as Symbiont A and Symbiont C) in A. pacifica. Symbiont A and the A. crypta symbiont were affiliated with thioautotrophic symbionts of bathymodiolin mussels from deep-sea reducing environments, while Symbiont C was closely related to free-living heterotrophic bacteria. The symbionts in A. crypta were intracellular within epithelial cells of the apical region of the gills and were extracellular in A. pacifica. No spatial partitioning was observed between the two phylotypes in A. pacifica in fluorescence in situ hybridization experiments. Stable isotopic analyses of carbon and sulfur indicated the chemoautotrophic nature of A. crypta and mixotrophic nature of A. pacifica. Molecular phylogenetic analyses of the host mussels showed that A. crypta constituted a monophyletic clade with other intracellular symbiotic (endosymbiotic) mussels and that A. pacifica was the sister group of all endosymbiotic mussels. Conclusions/Significance These results strongly suggest that the symbiosis in A. pacifica is at an earlier stage in evolution than other endosymbiotic mussels. Whale falls and other modern biogenic reducing environments may act as refugia

  3. Rice arbuscular mycorrhiza as a tool to study the molecular mechanisms of fungal symbiosis and a potential target to increase productivity.

    PubMed

    Nakagawa, Tomomi; Imaizumi-Anraku, Haruko

    2015-12-01

    Rice (Oryza sativa L.) is a monocot model crop for cereal molecular biology. Following the emergence of molecular genetics of arbuscular mycorrhizal (AM) symbiosis in model legumes in the 1990s, studies on rice genetic resources have considerably contributed to our understanding of the molecular mechanisms and evolution of root intracellular symbioses.In this review, we trace the history of these studies and suggest the potential utility of AM symbiosis for improvement in rice productivity.

  4. The role of carbon in fungal nutrient uptake and transport: implications for resource exchange in the arbuscular mycorrhizal symbiosis.

    PubMed

    Fellbaum, Carl R; Mensah, Jerry A; Pfeffer, Philip E; Kiers, E Toby; Bücking, Heike

    2012-11-01

    The arbuscular mycorrhizal (AM) symbiosis, which forms between plant hosts and ubiquitous soil fungi of the phylum Glomeromycota, plays a key role for the nutrient uptake of the majority of land plants, including many economically important crop species. AM fungi take up nutrients from the soil and exchange them for photosynthetically fixed carbon from the host. While our understanding of the exact mechanisms controlling carbon and nutrient exchange is still limited, we recently demonstrated that (i) carbon acts as an important trigger for fungal N uptake and transport, (ii) the fungus changes its strategy in response to an exogenous supply of carbon, and that (iii) both plants and fungi reciprocally reward resources to those partners providing more benefit. Here, we summarize recent research findings and discuss the implications of these results for fungal and plant control of resource exchange in the AM symbiosis.

  5. Adapted to change: The rapid development of symbiosis in newly settled, fast-maturing chemosymbiotic mussels in the deep sea.

    PubMed

    Laming, Sven R; Duperron, Sébastien; Gaudron, Sylvie M; Hilário, Ana; Cunha, Marina R

    2015-12-01

    Symbioses between microbiota and marine metazoa occur globally at chemosynthetic habitats facing imminent threat from anthropogenic disturbance, yet little is known concerning the role of symbiosis during early development in chemosymbiotic metazoans: a critical period in any benthic species' lifecycle. The emerging symbiosis of Idas (sensu lato) simpsoni mussels undergoing development is assessed over a post-larval-to-adult size spectrum using histology and fluorescence in situ hybridisation (FISH). Post-larval development shows similarities to that of both heterotrophic and chemosymbiotic mussels. Data from newly settled specimens confirm aposymbiotic, planktotrophic larval development. Sulphur-oxidising (SOX) symbionts subsequently colonise multiple exposed, non-ciliated epithelia shortly after metamorphosis, but only become abundant on gills as these expand with greater host size. This wide-spread bathymodiolin recorded from sulphidic wood, bone and cold-seep habitats, displays a suite of adaptive traits that could buffer against anthropogenic disturbance.

  6. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2001-01-01

    An overview of the industrial diamond industry is provided. More than 90 percent of the industrial diamond consumed in the U.S. and the rest of the world is manufactured diamond. Ireland, Japan, Russia, and the U.S. produce 75 percent of the global industrial diamond output. In 2000, the U.S. was the largest market for industrial diamond. Industrial diamond applications, prices for industrial diamonds, imports and exports of industrial diamonds, the National Defense Stockpile of industrial diamonds, and the outlook for the industrial diamond market are discussed.

  7. A 2-component system is involved in the early stages of the Pisolithus tinctorius-Pinus greggii symbiosis.

    PubMed

    Herrera-Martínez, Aseneth; Ruiz-Medrano, Roberto; Galván-Gordillo, Santiago Valentín; Toscano Morales, Roberto; Gómez-Silva, Lidia; Valdés, María; Hinojosa-Moya, Jesús; Xoconostle-Cázares, Beatriz

    2014-01-01

    Ectomycorrhizal symbiosis results in profound morphological and physiological modifications in both plant and fungus. This in turn is the product of differential gene expression in both co-symbionts, giving rise to specialized cell types capable of performing novel functions. During the precolonization stage, chemical signals from root exudates are sensed by the ectomycorrizal fungus, and vice versa, which are in principle responsible for the observed change in the developmental symbionts program. Little is known about the molecular mechanisms involved in the signaling and recognition between ectomycorrhizal fungi and their host plants. In the present work, we characterized a novel lactone, termed pinelactone, and identified a gene encoding for a histidine kinase in Pisolithus tictorius, which function is proposed to be the perception of the aforementioned metabolites. In this study, the use of closantel, a specific inhibitor of histidine kinase phosphorylation, affected the capacity for fungal colonization in the symbiosis between Pisolithus tinctorius and Pinus greggii, indicating that a 2-component system (TCS) may operate in the early events of plant-fungus interaction. Indeed, the metabolites induced the accumulation of Pisolithus tinctorius mRNA for a putative histidine kinase (termed Pthik1). Of note, Pthik1 was able to partially complement a S. cerevisiae histidine kinase mutant, demonstrating its role in the response to the presence of the aforementioned metabolites. Our results indicate a role of a 2-component pathway in the early stages of ectomycorrhizal symbiosis before colonization. Furthermore, a novel lactone from Pinus greggii root exudates may activate a signal transduction pathway that contributes to the establishment of the ectomycorrhizal symbiosis.

  8. A Lipidomic Approach to Understanding Free Fatty Acid Lipogenesis Derived from Dissolved Inorganic Carbon within Cnidarian-Dinoflagellate Symbiosis

    PubMed Central

    Dunn, Simon R.; Thomas, Michael C.; Nette, Geoffrey W.; Dove, Sophie G.

    2012-01-01

    The cnidarian-dinoflagellate symbiosis is arguably one of the most important within the marine environment in that it is integral to the formation of coral reefs. However, the regulatory processes that perpetuate this symbiosis remain unresolved. It is essential to understand these processes, if we are to elucidate the mechanisms that support growth and resource accumulation by coral host, and conversely, recently observed reduction and/or mortality of corals in response to rapid environmental change. This study specifically focused on one area of metabolic activity within the symbiosis, that of free fatty acid synthesis within both the dinoflagellate symbionts and cnidarian host. The main model system used was Aiptasia pulchella and Symbiodinium sp. in combination with aposymbiotic A. pulchella, the symbiotic coral Acropora millepora system and dinoflagellate culture. Fatty acids (FAs) were selected because of their multiple essential roles inclusive of energy storage (resource accumulation), membrane structure fluidity and cell signaling. The study addressed free FA lipogenesis by using a new method of enriched stable isotopic (13C) incorporation from dissolved inorganic carbon (DI13C) combined with HPLC-MS. FAs derived from DI13C aligned with a mixture of known lipogenesis pathways with the addition of some unusual FAs. After 120 hr, 13C-enriched FA synthesis rates were attributed to only a complex integration of both n–3 and n–6 lipogenesis pathways within the dinoflagellate symbionts. Furthermore, there was no detectible evidence of symbiont derived enriched isotope fatty acids, catabolized 13C derivatives or DI13C being directly utilized, in host late n–6 pathway long-chain FA lipogenesis. These findings do not align with a popular mutualistic translocation model with respect to the use of translocated symbiont photoassimilates in host long-chain FA lipogenesis, which has important connotations for linking nutrient sources with metabolite production and

  9. A lipidomic approach to understanding free fatty acid lipogenesis derived from dissolved inorganic carbon within cnidarian-dinoflagellate symbiosis.

    PubMed

    Dunn, Simon R; Thomas, Michael C; Nette, Geoffrey W; Dove, Sophie G

    2012-01-01

    The cnidarian-dinoflagellate symbiosis is arguably one of the most important within the marine environment in that it is integral to the formation of coral reefs. However, the regulatory processes that perpetuate this symbiosis remain unresolved. It is essential to understand these processes, if we are to elucidate the mechanisms that support growth and resource accumulation by coral host, and conversely, recently observed reduction and/or mortality of corals in response to rapid environmental change. This study specifically focused on one area of metabolic activity within the symbiosis, that of free fatty acid synthesis within both the dinoflagellate symbionts and cnidarian host. The main model system used was Aiptasia pulchella and Symbiodinium sp. in combination with aposymbiotic A. pulchella, the symbiotic coral Acropora millepora system and dinoflagellate culture. Fatty acids (FAs) were selected because of their multiple essential roles inclusive of energy storage (resource accumulation), membrane structure fluidity and cell signaling. The study addressed free FA lipogenesis by using a new method of enriched stable isotopic ((13)C) incorporation from dissolved inorganic carbon (DI(13)C) combined with HPLC-MS. FAs derived from DI(13)C aligned with a mixture of known lipogenesis pathways with the addition of some unusual FAs. After 120 hr, (13)C-enriched FA synthesis rates were attributed to only a complex integration of both n-3 and n-6 lipogenesis pathways within the dinoflagellate symbionts. Furthermore, there was no detectible evidence of symbiont derived enriched isotope fatty acids, catabolized (13)C derivatives or DI(13)C being directly utilized, in host late n-6 pathway long-chain FA lipogenesis. These findings do not align with a popular mutualistic translocation model with respect to the use of translocated symbiont photoassimilates in host long-chain FA lipogenesis, which has important connotations for linking nutrient sources with metabolite

  10. Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes.

    PubMed

    Kowalski, Kurt P; Bacon, Charles; Bickford, Wesley; Braun, Heather; Clay, Keith; Leduc-Lapierre, Michèle; Lillard, Elizabeth; McCormick, Melissa K; Nelson, Eric; Torres, Monica; White, James; Wilcox, Douglas A

    2015-01-01

    A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective control approaches. In this manuscript, we review microbial relationships with plants, outline steps necessary to develop invasive species control strategies that are based on those relationships, and use the invasive plant species Phragmites australis (common reed) as an example of how development of microbial-based control strategies can be enhanced using a collective impact approach. The proposed science agenda, developed by the Collaborative for Microbial Symbiosis and Phragmites Management, contains a foundation of sequential steps and mutually-reinforcing tasks to guide the development of microbial-based control strategies for Phragmites and other invasive species. Just as the science of plant-microbial symbiosis can be transferred for use in other invasive species, so too can the model of collective impact be applied to other avenues of research and management.

  11. Symbiosis-related pea genes modulate fungal and plant gene expression during the arbuscule stage of mycorrhiza with Glomus intraradices.

    PubMed

    Kuznetsova, Elena; Seddas-Dozolme, Pascale M A; Arnould, Christine; Tollot, Marie; van Tuinen, Diederik; Borisov, Alexey; Gianinazzi, Silvio; Gianinazzi-Pearson, Vivienne

    2010-08-01

    The arbuscular mycorrhiza association results from a successful interaction between genomes of the plant and fungal symbiotic partners. In this study, we analyzed the effect of inactivation of late-stage symbiosis-related pea genes on symbiosis-associated fungal and plant molecular responses in order to gain insight into their role in the functional mycorrhizal association. The expression of a subset of ten fungal and eight plant genes, previously reported to be activated during mycorrhiza development, was compared in Glomus intraradices-inoculated wild-type and isogenic genotypes of pea mutated for the PsSym36, PsSym33, and PsSym40 genes where arbuscule formation is inhibited or fungal turnover modulated, respectively. Microdissection was used to corroborate arbuscule-related fungal gene expression. Molecular responses varied between pea genotypes and with fungal development. Most of the fungal genes were downregulated when arbuscule formation was defective, and several were upregulated with more rapid fungal development. Some of the plant genes were also affected by inactivation of the PsSym36, PsSym33, and PsSym40 loci, but in a more time-dependent way during root colonization by G. intraradices. Results indicate a role of the late-stage symbiosis-related pea genes not only in mycorrhiza development but also in the symbiotic functioning of arbuscule-containing cells.

  12. An experimental test of the symbiosis specificity between the ciliate Paramecium bursaria and strains of the unicellular green alga Chlorella.

    PubMed

    Summerer, Monika; Sonntag, Bettina; Sommaruga, Ruben

    2007-08-01

    The ciliate Paramecium bursaria living in mutualistic relationship with the unicellular green alga Chlorella is known to be easily infected by various potential symbionts/parasites such as bacteria, yeasts and other algae. Permanent symbiosis, however, seems to be restricted to Chlorella taxa. To test the specificity of this association, we designed infection experiments with two aposymbiotic P. bursaria strains and Chlorella symbionts isolated from four Paramecium strains, seven other ciliate hosts and two Hydra strains, as well as three free-living Chlorella species. Paramecium bursaria established stable symbioses with all tested Chlorella symbionts of ciliates, but never with symbiotic Chlorella of Hydra viridissima or with free-living Chlorella. Furthermore, we tested the infection specificity of P. bursaria with a 1:1:1 mixture of three compatible Chlorella strains, including the native symbiont, and then identified the strain of the newly established symbiosis by sequencing the internal transcribed spacer region 1 of the 18S rRNA gene. The results indicated that P. bursaria established symbiosis with its native symbiont. We conclude that despite clear preferences for their native Chlorella, the host-symbiont relationship in P. bursaria is flexible.

  13. Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes.

    PubMed

    Kowalski, Kurt P; Bacon, Charles; Bickford, Wesley; Braun, Heather; Clay, Keith; Leduc-Lapierre, Michèle; Lillard, Elizabeth; McCormick, Melissa K; Nelson, Eric; Torres, Monica; White, James; Wilcox, Douglas A

    2015-01-01

    A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective control approaches. In this manuscript, we review microbial relationships with plants, outline steps necessary to develop invasive species control strategies that are based on those relationships, and use the invasive plant species Phragmites australis (common reed) as an example of how development of microbial-based control strategies can be enhanced using a collective impact approach. The proposed science agenda, developed by the Collaborative for Microbial Symbiosis and Phragmites Management, contains a foundation of sequential steps and mutually-reinforcing tasks to guide the development of microbial-based control strategies for Phragmites and other invasive species. Just as the science of plant-microbial symbiosis can be transferred for use in other invasive species, so too can the model of collective impact be applied to other avenues of research and management. PMID:25745417

  14. Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes

    PubMed Central

    Kowalski, Kurt P.; Bacon, Charles; Bickford, Wesley; Braun, Heather; Clay, Keith; Leduc-Lapierre, Michèle; Lillard, Elizabeth; McCormick, Melissa K.; Nelson, Eric; Torres, Monica; White, James; Wilcox, Douglas A.

    2015-01-01

    A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective control approaches. In this manuscript, we review microbial relationships with plants, outline steps necessary to develop invasive species control strategies that are based on those relationships, and use the invasive plant species Phragmites australis (common reed) as an example of how development of microbial-based control strategies can be enhanced using a collective impact approach. The proposed science agenda, developed by the Collaborative for Microbial Symbiosis and Phragmites Management, contains a foundation of sequential steps and mutually-reinforcing tasks to guide the development of microbial-based control strategies for Phragmites and other invasive species. Just as the science of plant-microbial symbiosis can be transferred for use in other invasive species, so too can the model of collective impact be applied to other avenues of research and management. PMID:25745417

  15. SYMBIOSIS: development, implementation, and assessment of a model curriculum across biology and mathematics at the introductory level.

    PubMed

    Depelteau, Audrey M; Joplin, Karl H; Govett, Aimee; Miller, Hugh A; Seier, Edith

    2010-01-01

    "It takes a lot of courage to release the familiar and seemingly secure, to embrace the new. But there is no real security in what is no longer meaningful. There is more security in the adventurous and exciting, for in movement there is life, and in change there is power." Alan Cohen (Used by permission. All rights reserved. For more information on Alan Cohen's books and programs, see (www.alancohen.com.) With the support of the East Tennessee State University (ETSU) administration and a grant from Howard Hughes Medical Institute, the departments of Biological Sciences, Mathematics and Statistics, and Curriculum and Instruction have developed a biology-math integrated curriculum. An interdisciplinary faculty team, charged with teaching the 18 curriculum modules, designed this three-semester curriculum, known as SYMBIOSIS. This curriculum was piloted to two student cohorts during the developmental stage. The positive feedback and assessment results of this project have given us the foundation to implement the SYMBIOSIS curriculum as a replacement for the standard biology majors curriculum at the introductory level. This article addresses the history and development of the curriculum, previous assessment results and current assessment protocol, and the future of ETSU's approach to implementing the SYMBIOSIS curriculum. PMID:20810967

  16. Advancing the science of microbial symbiosis to support invasive species management: a case study on Phragmites in the Great Lakes

    USGS Publications Warehouse

    Kowalski, Kurt P.; Bacon, Charles R.; Bickford, Wesley A.; Braun, Heather A.; Clay, Keith; Leduc-Lapierre, Michele; Lillard, Elizabeth; McCormick, Melissa K.; Nelson, Eric; Torres, Monica; White, James W. C.; Wilcox, Douglas A.

    2015-01-01

    A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species. Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective control approaches. In this manuscript, we review microbial relationships with plants, outline steps necessary to develop invasive species control strategies that are based on those relationships, and use the invasive plant species Phragmites australis (common reed) as an example of how development of microbial-based control strategies can be enhanced using a collective impact approach. The proposed science agenda, developed by the Collaborative for Microbial Symbiosis andPhragmites Management, contains a foundation of sequential steps and mutually-reinforcing tasks to guide the development of microbial-based control strategies for Phragmites and other invasive species. Just as the science of plant-microbial symbiosis can be transferred for use in other invasive species, so too can the model of collective impact be applied to other avenues of research and management.

  17. Novel tools integrating metabolic and gene function to study the impact of the environment on coral symbiosis.

    PubMed

    Pernice, Mathieu; Levy, Oren

    2014-01-01

    The symbiotic dinoflagellates (genus Symbiodinium) inhabiting coral endodermal tissues are well known for their role as keystone symbiotic partners, providing corals with enormous amounts of energy acquired via photosynthesis and the absorption of dissolved nutrients. In the past few decades, corals reefs worldwide have been increasingly affected by coral bleaching (i.e., the breakdown of the symbiosis between corals and their dinoflagellate symbionts), which carries important socio-economic implications. Consequently, the number of studies focusing on the molecular and cellular processes underlying this biological phenomenon has grown rapidly, and symbiosis is now widely recognized as a major topic in coral biology. However, obtaining a clear image of the interplay between the environment and this mutualistic symbiosis remains challenging. Here, we review the potential of recent technological advances in molecular biology and approaches using stable isotopes to fill critical knowledge gaps regarding coral symbiotic function. Finally, we emphasize that the largest opportunity to achieve the full potential in this field arises from the integration of these technological advances.

  18. Colonization state influences the hemocyte proteome in a beneficial squid-Vibrio symbiosis.

    PubMed

    Schleicher, Tyler R; VerBerkmoes, Nathan C; Shah, Manesh; Nyholm, Spencer V

    2014-10-01

    The squid Euprymna scolopes and the luminescent bacterium Vibrio fischeri form a highly specific beneficial light organ symbiosis. Not only does the host have to select V. fischeri from the environment, but it must also prevent subsequent colonization by non-symbiotic microorganisms. Host macrophage-like hemocytes are believed to play a role in mediating the symbiosis with V. fischeri. Previous studies have shown that the colonization state of the light organ influences the host's hemocyte response to the symbiont. To further understand the molecular mechanisms behind this process, we used two quantitative mass-spectrometry-based proteomic techniques, isobaric tags for relative and absolute quantification (iTRAQ) and label-free spectral counting, to compare and quantify the adult hemocyte proteomes from colonized (sym) and uncolonized (antibiotic-treated/cured) squid. Overall, iTRAQ allowed for the quantification of 1,024 proteins with two or more peptides. Thirty-seven unique proteins were determined to be significantly different between sym and cured hemocytes (p value < 0.05), with 20 more abundant proteins and 17 less abundant in sym hemocytes. The label-free approach resulted in 1,241 proteins that were identified in all replicates. Of 185 unique proteins present at significantly different amounts in sym hemocytes (as determined by spectral counting), 92 were more abundant and 93 were less abundant. Comparisons between iTRAQ and spectral counting revealed that 30 of the 37 proteins quantified via iTRAQ exhibited trends similar to those identified by the label-free method. Both proteomic techniques mutually identified 16 proteins that were significantly different between the two groups of hemocytes (p value < 0.05). The presence of V. fischeri in the host light organ influenced the abundance of proteins associated with the cytoskeleton, adhesion, lysosomes, proteolysis, and the innate immune response. These data provide evidence that colonization by V. fischeri

  19. Colonization State Influences the Hemocyte Proteome in a Beneficial Squid–Vibrio Symbiosis*

    PubMed Central

    Schleicher, Tyler R.; VerBerkmoes, Nathan C.; Shah, Manesh; Nyholm, Spencer V.

    2014-01-01

    The squid Euprymna scolopes and the luminescent bacterium Vibrio fischeri form a highly specific beneficial light organ symbiosis. Not only does the host have to select V. fischeri from the environment, but it must also prevent subsequent colonization by non-symbiotic microorganisms. Host macrophage-like hemocytes are believed to play a role in mediating the symbiosis with V. fischeri. Previous studies have shown that the colonization state of the light organ influences the host's hemocyte response to the symbiont. To further understand the molecular mechanisms behind this process, we used two quantitative mass-spectrometry-based proteomic techniques, isobaric tags for relative and absolute quantification (iTRAQ) and label-free spectral counting, to compare and quantify the adult hemocyte proteomes from colonized (sym) and uncolonized (antibiotic-treated/cured) squid. Overall, iTRAQ allowed for the quantification of 1,024 proteins with two or more peptides. Thirty-seven unique proteins were determined to be significantly different between sym and cured hemocytes (p value < 0.05), with 20 more abundant proteins and 17 less abundant in sym hemocytes. The label-free approach resulted in 1,241 proteins that were identified in all replicates. Of 185 unique proteins present at significantly different amounts in sym hemocytes (as determined by spectral counting), 92 were more abundant and 93 were less abundant. Comparisons between iTRAQ and spectral counting revealed that 30 of the 37 proteins quantified via iTRAQ exhibited trends similar to those identified by the label-free method. Both proteomic techniques mutually identified 16 proteins that were significantly different between the two groups of hemocytes (p value < 0.05). The presence of V. fischeri in the host light organ influenced the abundance of proteins associated with the cytoskeleton, adhesion, lysosomes, proteolysis, and the innate immune response. These data provide evidence that colonization by V. fischeri

  20. Industrial garnet

    USGS Publications Warehouse

    Olson, D.W.

    2001-01-01

    A general overview of the industrial garnet industry is provided. About 20 percent of global industrial garnet production takes place in the U.S. During 2000, an estimated 300 kt of industrial garnets were produced worldwide. The U.S. is the world's largest consumer of industrial garnet, consuming 56.9 kt in 2000.

  1. 7 CFR 1215.8 - Industry information.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE POPCORN PROMOTION, RESEARCH, AND CONSUMER INFORMATION Popcorn Promotion, Research, and Consumer Information Order Definitions § 1215.8... of new markets, new marketing strategies, or increased efficiency for the popcorn industry,...

  2. Upscaling Arbuscular Mycorrhizal Symbiosis and Related Agroecosystems Services in Smallholder Farming Systems.

    PubMed

    Oruru, Marjorie Bonareri; Njeru, Ezekiel Mugendi

    2016-01-01

    Smallholder farming systems form unique ecosystems that can protect beneficial soil biota and form an important source of useful genetic resources. They are characterized by high level of agricultural diversity mainly focused on meeting farmers' needs. Unfortunately, these systems often experience poor crop production mainly associated with poor planning and resource scarcity. Soil fertility is among the primary challenges faced by smallholder farmers, which necessitate the need to come up with affordable and innovative ways of replenishing soils. One such way is the use of microbial symbionts such as arbuscular mycorrhizal fungi (AMF), a beneficial group of soil microbiota that form symbiotic associations with majority of cultivated crops and play a vital role in biological soil fertility, plant nutrition, and protection. AMF can be incorporated in smallholder farming systems to help better exploit chemical fertilizers inputs which are often unaffordable to many smallholder farmers. The present review highlights smallholder farming practices that could be innovatively redesigned to increase AMF symbiosis and related agroecosystem services. Indeed, the future of global food security depends on the success of smallholder farming systems, whose crop productivity depends on the services provided by well-functioning ecosystems, including soil fertility. PMID:26942194

  3. Nitric oxide and cnidarian bleaching: an eviction notice mediates breakdown of a symbiosis.

    PubMed

    Perez, Santiago; Weis, Virginia

    2006-07-01

    Nitric oxide (NO) is a free radical implicated in numerous cell signaling, physiological and pathophysiological processes of eukaryotic cells. Here, we describe the production of NO as part of the cellular stress response of the symbiotic sea anemone Aiptasia pallida, which hosts dinoflagellates from the genus Symbiodinium. We show that exposure to elevated temperatures induces symbiotic anemones to produce high levels of NO, leading to the collapse of the symbiosis. These results shed light on the poorly understood cellular mechanism through which elevated seawater temperature causes the release of symbiotic algae from symbiotic cnidarians, a detrimental process known as coral (cnidarian) bleaching. The results presented here show that the host cell is a major source of NO during exposure to elevated temperatures and that this constitutes a cytotoxic response leading to bleaching. These results have important evolutionary implications as the observed NO production in these basal metazoans displays many parallels to the cytotoxic inflammatory response to pathogens, a well-understood process in mammalian model systems. PMID:16809471

  4. Neo-Symbiosis: The Next Stage in the Evolution of Human Information Interaction

    SciTech Connect

    Griffith, Douglas; Greitzer, Frank L.

    2008-03-01

    We re-address the vision of human-computer symbiosis expressed by J. C. R. Licklider nearly a half-century ago, when he wrote: “The hope is that in not too many years, human brains and computing machines will be coupled together very tightly, and that the resulting partnership will think as no human brain has ever thought and process data in a way not approached by the information-handling machines we know today.” (Licklider, 1960). Unfortunately, little progress was made toward this vision over four decades following Licklider’s challenge, despite significant advancements in the fields of human factors and computer science. Licklider’s vision was largely forgotten. However, recent advances in information science and technology, psychology, and neuroscience have rekindled the potential of making the Licklider’s vision a reality. This paper provides a historical context for and updates the vision, and it argues that such a vision is needed as a unifying framework for advancing IS&T.

  5. The dual nature of haemocyanin in the establishment and persistence of the squid–vibrio symbiosis

    PubMed Central

    Kremer, Natacha; Schwartzman, Julia; Augustin, René; Zhou, Lawrence; Ruby, Edward G.; Hourdez, Stéphane; McFall-Ngai, Margaret J.

    2014-01-01

    We identified and sequenced from the squid Euprymna scolopes two isoforms of haemocyanin that share the common structural/physiological characteristics of haemocyanin from a closely related cephalopod, Sepia officinalis, including a pronounced Bohr effect. We examined the potential roles for haemocyanin in the animal's symbiosis with the luminous bacterium Vibrio fischeri. Our data demonstrate that, as in other cephalopods, the haemocyanin is primarily synthesized in the gills. It transits through the general circulation into other tissues and is exported into crypt spaces that support the bacterial partner, which requires oxygen for its bioluminescence. We showed that the gradient of pH between the circulating haemolymph and the matrix of the crypt spaces in adult squid favours offloading of oxygen from the haemocyanin to the symbionts. Haemocyanin is also localized to the apical surfaces and associated mucus of a juvenile-specific epithelium on which the symbionts gather, and where their specificity is determined during the recruitment into the association. The haemocyanin has an antimicrobial activity, which may be involved in this enrichment of V. fischeri during symbiont initiation. Taken together, these data provide evidence that the haemocyanin plays a role in shaping two stages of the squid–vibrio partnership. PMID:24807261

  6. Auxin Perception Is Required for Arbuscule Development in Arbuscular Mycorrhizal Symbiosis1[W

    PubMed Central

    Etemadi, Mohammad; Gutjahr, Caroline; Couzigou, Jean-Malo; Zouine, Mohamed; Lauressergues, Dominique; Timmers, Antonius; Audran, Corinne; Bouzayen, Mondher; Bécard, Guillaume; Combier, Jean-Philippe

    2014-01-01

    Most land plant species live in symbiosis with arbuscular mycorrhizal fungi. These fungi differentiate essential functional structures called arbuscules in root cortical cells from which mineral nutrients are released to the plant. We investigated the role of microRNA393 (miR393), an miRNA that targets several auxin receptors, in arbuscular mycorrhizal root colonization. Expression of the precursors of the miR393 was down-regulated during mycorrhization in three different plant species: Solanum lycopersicum, Medicago truncatula, and Oryza sativa. Treatment of S. lycopersicum, M. truncatula, and O. sativa roots with concentrations of synthetic auxin analogs that did not affect root development stimulated mycorrhization, particularly arbuscule formation. DR5-GUS, a reporter for auxin response, was preferentially expressed in root cells containing arbuscules. Finally, overexpression of miR393 in root tissues resulted in down-regulation of auxin receptor genes (transport inhibitor response1 and auxin-related F box) and underdeveloped arbuscules in all three plant species. These results support the conclusion that miR393 is a negative regulator of arbuscule formation by hampering auxin perception in arbuscule-containing cells. PMID:25096975

  7. Microbial experimental evolution as a novel research approach in the Vibrionaceae and squid-Vibrio symbiosis

    PubMed Central

    Soto, William; Nishiguchi, Michele K.

    2014-01-01

    The Vibrionaceae are a genetically and metabolically diverse family living in aquatic habitats with a great propensity toward developing interactions with eukaryotic microbial and multicellular hosts (as either commensals, pathogens, and mutualists). The Vibrionaceae frequently possess a life history cycle where bacteria are attached to a host in one phase and then another where they are free from their host as either part of the bacterioplankton or adhered to solid substrates such as marine sediment, riverbeds, lakebeds, or floating particulate debris. These two stages in their life history exert quite distinct and separate selection pressures. When bound to solid substrates or to host cells, the Vibrionaceae can also exist as complex biofilms. The association between bioluminescent Vibrio spp. and sepiolid squids (Cephalopoda: Sepiolidae) is an experimentally tractable model to study bacteria and animal host interactions, since the symbionts and squid hosts can be maintained in the laboratory independently of one another. The bacteria can be grown in pure culture and the squid hosts raised gnotobiotically with sterile light organs. The partnership between free-living Vibrio symbionts and axenic squid hatchlings emerging from eggs must be renewed every generation of the cephalopod host. Thus, symbiotic bacteria and animal host can each be studied alone and together in union. Despite virtues provided by the Vibrionaceae and sepiolid squid-Vibrio symbiosis, these assets to evolutionary biology have yet to be fully utilized for microbial experimental evolution. Experimental evolution studies already completed are reviewed, along with exploratory topics for future study. PMID:25538686

  8. The dual nature of haemocyanin in the establishment and persistence of the squid-vibrio symbiosis.

    PubMed

    Kremer, Natacha; Schwartzman, Julia; Augustin, René; Zhou, Lawrence; Ruby, Edward G; Hourdez, Stéphane; McFall-Ngai, Margaret J

    2014-06-22

    We identified and sequenced from the squid Euprymna scolopes two isoforms of haemocyanin that share the common structural/physiological characteristics of haemocyanin from a closely related cephalopod, Sepia officinalis, including a pronounced Bohr effect. We examined the potential roles for haemocyanin in the animal's symbiosis with the luminous bacterium Vibrio fischeri. Our data demonstrate that, as in other cephalopods, the haemocyanin is primarily synthesized in the gills. It transits through the general circulation into other tissues and is exported into crypt spaces that support the bacterial partner, which requires oxygen for its bioluminescence. We showed that the gradient of pH between the circulating haemolymph and the matrix of the crypt spaces in adult squid favours offloading of oxygen from the haemocyanin to the symbionts. Haemocyanin is also localized to the apical surfaces and associated mucus of a juvenile-specific epithelium on which the symbionts gather, and where their specificity is determined during the recruitment into the association. The haemocyanin has an antimicrobial activity, which may be involved in this enrichment of V. fischeri during symbiont initiation. Taken together, these data provide evidence that the haemocyanin plays a role in shaping two stages of the squid-vibrio partnership.

  9. Upscaling Arbuscular Mycorrhizal Symbiosis and Related Agroecosystems Services in Smallholder Farming Systems

    PubMed Central

    Oruru, Marjorie Bonareri; Njeru, Ezekiel Mugendi

    2016-01-01

    Smallholder farming systems form unique ecosystems that can protect beneficial soil biota and form an important source of useful genetic resources. They are characterized by high level of agricultural diversity mainly focused on meeting farmers' needs. Unfortunately, these systems often experience poor crop production mainly associated with poor planning and resource scarcity. Soil fertility is among the primary challenges faced by smallholder farmers, which necessitate the need to come up with affordable and innovative ways of replenishing soils. One such way is the use of microbial symbionts such as arbuscular mycorrhizal fungi (AMF), a beneficial group of soil microbiota that form symbiotic associations with majority of cultivated crops and play a vital role in biological soil fertility, plant nutrition, and protection. AMF can be incorporated in smallholder farming systems to help better exploit chemical fertilizers inputs which are often unaffordable to many smallholder farmers. The present review highlights smallholder farming practices that could be innovatively redesigned to increase AMF symbiosis and related agroecosystem services. Indeed, the future of global food security depends on the success of smallholder farming systems, whose crop productivity depends on the services provided by well-functioning ecosystems, including soil fertility. PMID:26942194

  10. Arbuscular Mycorrhiza–Specific Signaling in Rice Transcends the Common Symbiosis Signaling Pathway[W

    PubMed Central

    Gutjahr, Caroline; Banba, Mari; Croset, Vincent; An, Kyungsook; Miyao, Akio; An, Gynheung; Hirochika, Hirohiko; Imaizumi-Anraku, Haruko; Paszkowski, Uta

    2008-01-01

    Knowledge about signaling in arbuscular mycorrhizal (AM) symbioses is currently restricted to the common symbiosis (SYM) signaling pathway discovered in legumes. This pathway includes calcium as a second messenger and regulates both AM and rhizobial symbioses. Both monocotyledons and dicotyledons form symbiotic associations with AM fungi, and although they differ markedly in the organization of their root systems, the morphology of colonization is similar. To identify and dissect AM-specific signaling in rice (Oryza sativa), we developed molecular phenotyping tools based on gene expression patterns that monitor various steps of AM colonization. These tools were used to distinguish common SYM-dependent and -independent signaling by examining rice mutants of selected putative legume signaling orthologs predicted to be perturbed both upstream (CASTOR and POLLUX) and downstream (CCAMK and CYCLOPS) of the central, calcium-spiking signal. All four mutants displayed impaired AM interactions and altered AM-specific gene expression patterns, therefore demonstrating functional conservation of SYM signaling between distant plant species. In addition, differential gene expression patterns in the mutants provided evidence for AM-specific but SYM-independent signaling in rice and furthermore for unexpected deviations from the SYM pathway downstream of calcium spiking. PMID:19033527

  11. The arbuscular mycorrhizal symbiosis influences sulfur starvation responses of Medicago truncatula.

    PubMed

    Sieh, Daniela; Watanabe, Mutsumi; Devers, Emanuel A; Brueckner, Franziska; Hoefgen, Rainer; Krajinski, Franziska

    2013-01-01

    Arbuscular mycorrhizal (AM) symbiosis is a mutualistic interaction that occurs between the large majority of vascular plants and fungi of the phylum Glomeromycota. In addition to other nutrients, sulfur compounds are symbiotically transferred from AM fungus to host plants; however, the physiological importance of mycorrhizal-mediated sulfur for plant metabolism has not yet been determined. We applied different sulfur and phosphate fertilization treatments to Medicago truncatula and investigated whether mycorrhizal colonization influences leaf metabolite composition and the expression of sulfur starvation-related genes. The expression pattern of sulfur starvation-related genes indicated reduced sulfur starvation responses in mycorrhizal plants grown at 1 mM phosphate nutrition. Leaf metabolite concentrations clearly showed that phosphate stress has a greater impact than sulfur stress on plant metabolism, with no demand for sulfur at strong phosphate starvation. However, when phosphate nutrition is high enough, mycorrhizal colonization reduces sulfur stress responses, probably as a result of symbiotic sulfur uptake. Mycorrhizal colonization is able to reduce sulfur starvation responses in M. truncatula when the plant's phosphate status is high enough that sulfur starvation is of physiological importance. This clearly shows the impact of mycorrhizal sulfur transfer on plant metabolism.

  12. Rhizobium-Legume Symbiosis and Nitrogen Fixation under Severe Conditions and in an Arid Climate

    PubMed Central

    Zahran, Hamdi Hussein

    1999-01-01

    Biological N2 fixation represents the major source of N input in agricultural soils including those in arid regions. The major N2-fixing systems are the symbiotic systems, which can play a significant role in improving the fertility and productivity of low-N soils. The Rhizobium-legume symbioses have received most attention and have been examined extensively. The behavior of some N2-fixing systems under severe environmental conditions such as salt stress, drought stress, acidity, alkalinity, nutrient deficiency, fertilizers, heavy metals, and pesticides is reviewed. These major stress factors suppress the growth and symbiotic characteristics of most rhizobia; however, several strains, distributed among various species of rhizobia, are tolerant to stress effects. Some strains of rhizobia form effective (N2-fixing) symbioses with their host legumes under salt, heat, and acid stresses, and can sometimes do so under the effect of heavy metals. Reclamation and improvement of the fertility of arid lands by application of organic (manure and sewage sludge) and inorganic (synthetic) fertilizers are expensive and can be a source of pollution. The Rhizobium-legume (herb or tree) symbiosis is suggested to be the ideal solution to the improvement of soil fertility and the rehabilitation of arid lands and is an important direction for future research. PMID:10585971

  13. Altered Carbohydrates Allocation by Associated Bacteria-fungi Interactions in a Bark Beetle-microbe Symbiosis.

    PubMed

    Zhou, Fangyuan; Lou, Qiaozhe; Wang, Bo; Xu, Letian; Cheng, Chihang; Lu, Min; Sun, Jianghua

    2016-01-01

    Insect-microbe interaction is a key area of research in multiplayer symbiosis, yet little is known about the role of microbe-microbe interactions in insect-microbe symbioses. The red turpentine beetle (RTB) has destroyed millions of healthy pines in China and forms context-dependent relationships with associated fungi. The adult-associated fungus Leptographium procerum have played key roles in RTB colonization. However, common fungal associates (L. procerum and Ophiostoma minus) with RTB larvae compete for carbohydrates. Here, we report that dominant bacteria associated with RTB larvae buffer the competition by inhibiting the growth and D-glucose consumption of O. minus. However, they didn't inhibit the growth of L. procerum and forced this fungus to consume D-pinitol before consuming D-glucose, even though D-glucose was available and a better carbon source not only for L. procerum but also for RTB larvae and associated bacteria. This suggests the most frequently isolated bacteria associated with RTB larvae could affect fungal growth and the sequence of carbohydrate consumption. Thus, this regulates carbohydrate allocation in the RTB larva-microbe community, which may in turn benefit RTB larvae development. We also discuss the mechanism of carbohydrate allocation in the RTB larva-microbe community, and its potential contribution to the maintenance of a symbiotic community.

  14. [Symbiosis between the nodule bacterium Sinorhizobium meliloti and alfalfa (Medicago sativa) under salinization conditions].

    PubMed

    Ibragimova, M V; Rumiantseva, M L; Onishchuk, O P; Belova, V S; Kurchak, O N; Andronov, E E; Dziubenko, N I; Simarov, B V

    2006-01-01

    Two hundred forty-three isolates of alfalfa nodule bacteria (Sinorhizobium meliloti) were obtained from legume nodules and soils sampled in the northern Aral region, experiencing secondary salinization. Isolates obtained from nodules (N isolates) were significantly more salt-tolerant than those from soils (S isolates) when grown in a liquid medium with 3.5% NaCl. It was found that wild species of alfalfa, melilot, and trigonella preferably formed symbioses with salt-tolerant nodule bacteria in both salinized and nonsalinized soils. Only two alfalfa species, Medicago falcata and M. trautvetteri, formed efficient symbioses in soils contrasting in salinity. The formation of efficient symbiosis with alfalfa in the presence of 0.6% NaCl was studied in 36 isolates (N and S) differing in salt tolerance and symbiotic efficiency. Fifteen isolates formed efficient symbioses in the presence of salt. The increase in the dry weight of the plants was 25-68% higher than in the control group. The efficiency of symbiotic interaction under salinization conditions depended on the efficiency of the isolates under standard conditions but did not correlate with the source of nodule bacteria (soil or nodule) or their salt tolerance. The results indicate that nodule bacterium strains forming efficient symbioses under salinization conditions can be found.

  15. Arsenophonus insect symbionts are commonly infected with APSE, a bacteriophage involved in protective symbiosis.

    PubMed

    Duron, Olivier

    2014-10-01

    Insects commonly have intimate associations with maternally inherited bacterial symbionts. While many inherited symbionts are not essential for host survival, they often act as conditional mutualists, conferring protection against certain environmental stresses. The defensive symbiont Hamiltonella defensa which protects aphids against attacks by parasitoid wasps is one of these conditional mutualists. The protection afforded by Hamiltonella depends on the presence of a lysogenic bacteriophage, called APSE, encoding homologs of toxins that are suspected to target wasp cells. In this study, an important diversity of APSE variants is reported from another heritable symbiont, Arsenophonus, which is exceptionally widespread in insects. APSE was found in association with two-thirds of the Arsenophonus strains examined and from a variety of insect groups such as aphids, white flies, parasitoid wasps, triatomine bugs, louse flies, and bat flies. No APSE was, however, found from Arsenophonus relatives such as the recently described Aschnera chinzeii and ALO-3 endosymbionts. Phylogenetic investigations revealed that APSE has a long evolutionary history in heritable symbionts, being secondarily acquired by Hamiltonella through lateral transfer from Arsenophonus. Overall, this highlights the role of lateral transfer as a major evolutionary process shaping the emergence of defensive symbiosis in heritable bacteria. PMID:25041857

  16. Symbiosis with an endobacterium increases the fitness of a mycorrhizal fungus, raising its bioenergetic potential.

    PubMed

    Salvioli, Alessandra; Ghignone, Stefano; Novero, Mara; Navazio, Lorella; Venice, Francesco; Bagnaresi, Paolo; Bonfante, Paola

    2016-01-01

    Arbuscular mycorrhizal fungi (AMF) occur in the rhizosphere and in plant tissues as obligate symbionts, having key roles in plant evolution and nutrition. AMF possess endobacteria, and genome sequencing of the endobacterium Candidatus Glomeribacter gigasporarum revealed a reduced genome and a dependence on the fungal host. To understand the effect of bacteria on fungal fitness, we used next-generation sequencing to analyse the transcriptional profile of Gigaspora margarita in the presence and in the absence of its endobacterium. Genomic data on AMF are limited; therefore, we first generated a gene catalogue for G. margarita. Transcriptome analysis revealed that the endobacterium has a stronger effect on the pre-symbiotic phase of the fungus. Coupling transcriptomics with cell biology and physiological approaches, we demonstrate that the bacterium increases the fungal sporulation success, raises the fungal bioenergetic capacity, increasing ATP production, and eliciting mechanisms to detoxify reactive oxygen species. By using TAT peptide to translocate the bioluminescent calcium reporter aequorin, we demonstrated that the line with endobacteria had a lower basal intracellular calcium concentration than the cured line. Lastly, the bacteria seem to enhance the fungal responsiveness to strigolactones, the plant molecules that AMF perceive as branching factors. Although the endobacterium exacts a nutritional cost on the AMF, endobacterial symbiosis improves the fungal ecological fitness by priming mitochondrial metabolic pathways and giving the AMF more tools to face environmental stresses. Thus, we hypothesise that, as described for the human microbiota, endobacteria may increase AMF innate immunity.

  17. Is the coral-algae symbiosis really 'mutually beneficial' for the partners?

    PubMed

    Wooldridge, Scott A

    2010-07-01

    The consideration of 'mutual benefits' and partner cooperation have long been the accepted standpoint from which to draw inference about the onset, maintenance and breakdown of the coral-algae endosymbiosis. In this paper, I review recent research into the climate-induced breakdown of this important symbiosis (namely 'coral bleaching') that challenges the validity of this long-standing belief. Indeed, I introduce a more parsimonious explanation, in which the coral host exerts a 'controlled parasitism' over its algal symbionts that is akin to an enforced domestication arrangement. Far from being pathogenic, a range of well-established cellular processes are reviewed that support the role of the coral host as an active 'farmer' of the energy-rich photoassimilates from its captive symbionts. Importantly, this new paradigm reposes the deleterious bleaching response in terms of an envelope of environmental conditions in which the exploitative and captive measures of the coral host are severely restricted. The ramification of this new paradigm for developing management strategies that may assist the evolution of bleaching resistance in corals is discussed.

  18. The secret languages of coevolved symbioses: Insights from the Euprymna scolopes-Vibrio fischeri symbiosis

    PubMed Central

    McFall-Ngai, Margaret; Heath-Heckman, Elizabeth A. C.; Gillette, Amani A.; Peyer, Suzanne M.; Harvie, Elizabeth A.

    2011-01-01

    Recent research on a wide variety of systems has demonstrated that animals generally coevolve with their microbial symbionts. Although such relationships are most often established anew each generation, the partners associate with fidelity, i.e., they form exclusive alliances within the context of rich communities of non-symbiotic environmental microbes. The mechanisms by which this exclusivity is achieved and maintained remain largely unknown. Studies of the model symbiosis between the Hawaiian squid Euprymna scolopes and the marine luminous bacterium Vibrio fischeri provide evidence that the interplay between evolutionarily conserved features of the innate immune system, most notably MAMP/PRR interactions, and a specific feature of this association, i.e., luminescence, are critical for development and maintenance of this association. As such, in this partnership and perhaps others, symbiotic exclusivity is mediated by the synergism between a general animal-microbe ‘language’ and a ‘secret language’ that is decipherable only by the specific partners involved. PMID:22154556

  19. Cyanobacteria produce a high variety of hepatotoxic peptides in lichen symbiosis.

    PubMed

    Kaasalainen, Ulla; Fewer, David P; Jokela, Jouni; Wahlsten, Matti; Sivonen, Kaarina; Rikkinen, Jouko

    2012-04-10

    Lichens are symbiotic associations between fungi and photosynthetic algae or cyanobacteria. Microcystins are potent toxins that are responsible for the poisoning of both humans and animals. These toxins are mainly associated with aquatic cyanobacterial blooms, but here we show that the cyanobacterial symbionts of terrestrial lichens from all over the world commonly produce microcystins. We screened 803 lichen specimens from five different continents for cyanobacterial toxins by amplifying a part of the gene cluster encoding the enzyme complex responsible for microcystin production and detecting toxins directly from lichen thalli. We found either the biosynthetic genes for making microcystins or the toxin itself in 12% of all analyzed lichen specimens. A plethora of different microcystins was found with over 50 chemical variants, and many of the variants detected have only rarely been reported from free-living cyanobacteria. In addition, high amounts of nodularin, up to 60 μg g(-1), were detected from some lichen thalli. This microcystin analog and potent hepatotoxin has previously been known only from the aquatic bloom-forming genus Nodularia. Our results demonstrate that the production of cyanobacterial hepatotoxins in lichen symbiosis is a global phenomenon and occurs in many different lichen lineages. The very high genetic diversity of the mcyE gene and the chemical diversity of microcystins suggest that lichen symbioses may have been an important environment for diversification of these cyanobacteria.

  20. Fungal and cyanobacterial gene expression in a lichen symbiosis: Effect of temperature and location.

    PubMed

    Steinhäuser, Sophie S; Andrésson, Ólafur S; Pálsson, Arnar; Werth, Silke

    2016-10-01

    Organisms have evolved different cellular mechanisms to deal with environmental stress, primarily through complex molecular mechanisms including protein refolding and DNA repair. As mutualistic symbioses, lichens offer the possibility of analyzing molecular stress responses in a particularly tight interspecific relationship. We study the widespread cyanolichen Peltigera membranacea, a key player in carbon and nitrogen cycling in terrestrial ecosystems at northern latitudes. We ask whether increased temperature is reflected in mRNA levels of selected damage control genes, and do the response patterns show geographical associations? Using real-time PCR quantification of 38 transcripts, differential expression was demonstrated for nine cyanobacterial and nine fungal stress response genes (plus the fungal symbiosis-related lec2 gene) when the temperature was increased from 5 °C to 15 °C and 25 °C. Principle component analysis (PCA) revealed two gene groups with different response patterns. Whereas a set of cyanobacterial DNA repair genes and the fungal lec2 (PC1 group) showed an expression drop at 15 °C vs. 5 °C, most fungal candidates (PC2 group) showed increased expression at 25 °C vs. 5 °C. PC1 responses also correlated with elevation. The correlated downregulation of lec2 and cyanobacterial DNA repair genes suggests a possible interplay between the symbionts warranting further studies. PMID:27647237

  1. Characterization and function of carbonic anhydrases in the zooxanthellae-giant clam symbiosis.

    PubMed

    Baillie, B K; Yellowlees, D

    1998-03-22

    Carbonic anhydrase (CA) has been purified from the host tissue of Tridacna gigas, a clam that lives in symbiosis with the dinoflagellate alga, Symbiodinium. At least two isoforms of CA were identified in both gill and mantle tissue. The larger (70 kDa) isoform is a glycoprotein with both N- and O-glycans attached and has highest homology to CAII. It is associated with the membrane fraction while the smaller (32 kDa) is present in the aqueous phase in both tissues. The 32 kDa CA has high homology with mammalian CAI at the N-terminus. Both isoforms cross-reacted with antibodies to CAII from chicken. Immunohistology demonstrated that the 70 kDa CA is present within the ciliated branchial filaments and cells lining the tertiary water channels in the gills of T. gigas. This is consistent with a role in the transport of inorganic carbon (Ci) to the haemolymph and therefore supply of Ci to the zooxanthellae. CA was also detected in mantle epithelial cells where it may also contribute to Ci supply to the zooxanthellae. The hyaline body and nerve tissue in the mantle express the 70 kDa CA where it may be involved in light sensing and nervous transmission.

  2. Altered Carbohydrates Allocation by Associated Bacteria-fungi Interactions in a Bark Beetle-microbe Symbiosis

    PubMed Central

    Zhou, Fangyuan; Lou, Qiaozhe; Wang, Bo; Xu, Letian; Cheng, Chihang; Lu, Min; Sun, Jianghua

    2016-01-01

    Insect-microbe interaction is a key area of research in multiplayer symbiosis, yet little is known about the role of microbe-microbe interactions in insect-microbe symbioses. The red turpentine beetle (RTB) has destroyed millions of healthy pines in China and forms context-dependent relationships with associated fungi. The adult-associated fungus Leptographium procerum have played key roles in RTB colonization. However, common fungal associates (L. procerum and Ophiostoma minus) with RTB larvae compete for carbohydrates. Here, we report that dominant bacteria associated with RTB larvae buffer the competition by inhibiting the growth and D-glucose consumption of O. minus. However, they didn’t inhibit the growth of L. procerum and forced this fungus to consume D-pinitol before consuming D-glucose, even though D-glucose was available and a better carbon source not only for L. procerum but also for RTB larvae and associated bacteria. This suggests the most frequently isolated bacteria associated with RTB larvae could affect fungal growth and the sequence of carbohydrate consumption. Thus, this regulates carbohydrate allocation in the RTB larva-microbe community, which may in turn benefit RTB larvae development. We also discuss the mechanism of carbohydrate allocation in the RTB larva-microbe community, and its potential contribution to the maintenance of a symbiotic community. PMID:26839264

  3. Altered Carbohydrates Allocation by Associated Bacteria-fungi Interactions in a Bark Beetle-microbe Symbiosis.

    PubMed

    Zhou, Fangyuan; Lou, Qiaozhe; Wang, Bo; Xu, Letian; Cheng, Chihang; Lu, Min; Sun, Jianghua

    2016-01-01

    Insect-microbe interaction is a key area of research in multiplayer symbiosis, yet little is known about the role of microbe-microbe interactions in insect-microbe symbioses. The red turpentine beetle (RTB) has destroyed millions of healthy pines in China and forms context-dependent relationships with associated fungi. The adult-associated fungus Leptographium procerum have played key roles in RTB colonization. However, common fungal associates (L. procerum and Ophiostoma minus) with RTB larvae compete for carbohydrates. Here, we report that dominant bacteria associated with RTB larvae buffer the competition by inhibiting the growth and D-glucose consumption of O. minus. However, they didn't inhibit the growth of L. procerum and forced this fungus to consume D-pinitol before consuming D-glucose, even though D-glucose was available and a better carbon source not only for L. procerum but also for RTB larvae and associated bacteria. This suggests the most frequently isolated bacteria associated with RTB larvae could affect fungal growth and the sequence of carbohydrate consumption. Thus, this regulates carbohydrate allocation in the RTB larva-microbe community, which may in turn benefit RTB larvae development. We also discuss the mechanism of carbohydrate allocation in the RTB larva-microbe community, and its potential contribution to the maintenance of a symbiotic community. PMID:26839264

  4. Chloroplast symbiosis in a marine ciliate: ecophysiology and the risks and rewards of hosting foreign organelles.

    PubMed

    McManus, George B; Schoener, Donald M; Haberlandt, Katharine

    2012-01-01

    Simultaneous use of both heterotrophic and autotrophic metabolism ("mixotrophy") is common among protists. Strombidium rassoulzadegani is a planktonic mixotrophic marine ciliate that saves chloroplasts from its algal food and obtains a nutritional subsidy via photosynthesis. Cultures from the northeast, northwest, and southwest Atlantic Ocean show similar numerical response parameters (maximum growth rate, food concentration at which growth is half its maximum, and threshold food concentration for growth), and some isolates have been maintained in vitro for over 3 years. This ciliate grows equally well when fed on the green alga Tetraselmis chui (strain PLY429) or the cryptophyte Rhodomonas lens (strain RHODO). It appears to be an obligate mixotroph, requiring both food and light to achieve positive growth, when feeding on either of these algae. However, it has also been grown for several weeks (>10 generations) heterotrophically on the dinoflagellate Prorocentrum minimum (strain EXUV) during which it grows better in dark than in light. In this paper, we review the ecology of S. rassoulzadegani, discuss some aspects of its photo- and feeding physiology, and speculate on benefits and costs to the ciliate of chloroplast symbiosis.

  5. Activation of Symbiosis Signaling by Arbuscular Mycorrhizal Fungi in Legumes and Rice[OPEN

    PubMed Central

    Sun, Jongho; Miller, J. Benjamin; Granqvist, Emma; Wiley-Kalil, Audrey; Gobbato, Enrico; Maillet, Fabienne; Cottaz, Sylvain; Samain, Eric; Venkateshwaran, Muthusubramanian; Fort, Sébastien; Morris, Richard J.; Ané, Jean-Michel; Dénarié, Jean; Oldroyd, Giles E.D.

    2015-01-01

    Establishment of arbuscular mycorrhizal interactions involves plant recognition of diffusible signals from the fungus, including lipochitooligosaccharides (LCOs) and chitooligosaccharides (COs). Nitrogen-fixing rhizobial bacteria that associate with leguminous plants also signal to their hosts via LCOs, the so-called Nod factors. Here, we have assessed the induction of symbiotic signaling by the arbuscular mycorrhizal (Myc) fungal-produced LCOs and COs in legumes and rice (Oryza sativa). We show that Myc-LCOs and tetra-acetyl chitotetraose (CO4) activate the common symbiosis signaling pathway, with resultant calcium oscillations in root epidermal cells of Medicago truncatula and Lotus japonicus. The nature of the calcium oscillations is similar for LCOs produced by rhizobial bacteria and by mycorrhizal fungi; however, Myc-LCOs activate distinct gene expression. Calcium oscillations were activated in rice atrichoblasts by CO4, but not the Myc-LCOs, whereas a mix of CO4 and Myc-LCOs activated calcium oscillations in rice trichoblasts. In contrast, stimulation of lateral root emergence occurred following treatment with Myc-LCOs, but not CO4, in M. truncatula, whereas both Myc-LCOs and CO4 were active in rice. Our work indicates that legumes and non-legumes differ in their perception of Myc-LCO and CO signals, suggesting that different plant species respond to different components in the mix of signals produced by arbuscular mycorrhizal fungi. PMID:25724637

  6. Microbial experimental evolution as a novel research approach in the Vibrionaceae and squid-Vibrio symbiosis.

    PubMed

    Soto, William; Nishiguchi, Michele K

    2014-01-01

    The Vibrionaceae are a genetically and metabolically diverse family living in aquatic habitats with a great propensity toward developing interactions with eukaryotic microbial and multicellular hosts (as either commensals, pathogens, and mutualists). The Vibrionaceae frequently possess a life history cycle where bacteria are attached to a host in one phase and then another where they are free from their host as either part of the bacterioplankton or adhered to solid substrates such as marine sediment, riverbeds, lakebeds, or floating particulate debris. These two stages in their life history exert quite distinct and separate selection pressures. When bound to solid substrates or to host cells, the Vibrionaceae can also exist as complex biofilms. The association between bioluminescent Vibrio spp. and sepiolid squids (Cephalopoda: Sepiolidae) is an experimentally tractable model to study bacteria and animal host interactions, since the symbionts and squid hosts can be maintained in the laboratory independently of one another. The bacteria can be grown in pure culture and the squid hosts raised gnotobiotically with sterile light organs. The partnership between free-living Vibrio symbionts and axenic squid hatchlings emerging from eggs must be renewed every generation of the cephalopod host. Thus, symbiotic bacteria and animal host can each be studied alone and together in union. Despite virtues provided by the Vibrionaceae and sepiolid squid-Vibrio symbiosis, these assets to evolutionary biology have yet to be fully utilized for microbial experimental evolution. Experimental evolution studies already completed are reviewed, along with exploratory topics for future study.

  7. Symbiosis as a source of selectable epigenetic variation: taking the heat for the big guy

    PubMed Central

    Gilbert, Scott F.; McDonald, Emily; Boyle, Nicole; Buttino, Nicholas; Gyi, Lin; Mai, Mark; Prakash, Neelakantan; Robinson, James

    2010-01-01

    Evolutionary developmental biology is based on the principle that evolution arises from hereditable changes in development. Most of this new work has centred on changes in the regulatory components of the genome. However, recent studies (many of them documented in this volume) have shown that development also includes interactions between the organism and its environment. One area of interest concerns the importance of symbionts for the production of the normal range of phenotypes. Many, if not most, organisms have ‘outsourced’ some of their developmental signals to a set of symbionts that are expected to be acquired during development. Such intimate interactions between species are referred to as codevelopment, the production of a new individual through the coordinated interactions of several genotypically different species. Within the past 2 years, several research programmes have demonstrated that such codevelopmental schemes can be selected. We will focus on symbioses in coral reef cnidarians symbiosis, pea aphids and cactuses, wherein the symbiotic system provides thermotolerance for the composite organism. PMID:20083641

  8. (Iron regulation of gene expression in the Bradyrhizobium japonicum/soybean symbiosis)

    SciTech Connect

    Guerinot, M.L.

    1992-01-01

    We wish to address the question of whether iron plays a regulatory role in the Bradyrhizobium japonicum/soybeam symbiosis. Iron may be an important regulatory signal in planta as the bacteria must acquire iron from their plant hosts and iron-containing proteins figure prominently in all nitrogen-fixing symbioses. For example, the bacterial partner is believed to synthesize the heme moiety of leghemoglobin, which may represent as much as 25--30% of the total soluble protein in an infected plant cell. For this reason, we have focused our attention on the regulation by iron of the first step in the bacterial heme biosynthetic pathway. The enzyme which catalyzes this step, 5-aminolevulinic acid synthase, is encoded by the hemA gene which we had previously cloned and sequenced. Specific objectives include: to define the cis-acting sequences which confer iron regulation on the B. japonicum hemA gene; to identify trans-acting factors which regulate the expression of hemA by iron; to identify new loci which are transcriptionally responsive to changes in iron availability; and to examine the effects of mutations in various known regulatory genes for their effect on the expression of hemA.

  9. [Iron regulation of gene expression in the Bradyrhizobium japonicum/soybean symbiosis]. Progress report

    SciTech Connect

    Guerinot, M.L.

    1992-06-01

    We wish to address the question of whether iron plays a regulatory role in the Bradyrhizobium japonicum/soybeam symbiosis. Iron may be an important regulatory signal in planta as the bacteria must acquire iron from their plant hosts and iron-containing proteins figure prominently in all nitrogen-fixing symbioses. For example, the bacterial partner is believed to synthesize the heme moiety of leghemoglobin, which may represent as much as 25--30% of the total soluble protein in an infected plant cell. For this reason, we have focused our attention on the regulation by iron of the first step in the bacterial heme biosynthetic pathway. The enzyme which catalyzes this step, 5-aminolevulinic acid synthase, is encoded by the hemA gene which we had previously cloned and sequenced. Specific objectives include: to define the cis-acting sequences which confer iron regulation on the B. japonicum hemA gene; to identify trans-acting factors which regulate the expression of hemA by iron; to identify new loci which are transcriptionally responsive to changes in iron availability; and to examine the effects of mutations in various known regulatory genes for their effect on the expression of hemA.

  10. Heritability of symbiont density reveals distinct regulatory mechanisms in a tripartite symbiosis.

    PubMed

    Parkinson, Jasmine F; Gobin, Bruno; Hughes, William O H

    2016-04-01

    Beneficial eukaryotic-bacterial partnerships are integral to animal and plant evolution. Understanding the density regulation mechanisms behind bacterial symbiosis is essential to elucidating the functional balance between hosts and symbionts. Citrus mealybugs, Planococcus citri (Risso), present an excellent model system for investigating the mechanisms of symbiont density regulation. They contain two obligate nutritional symbionts, Moranella endobia, which resides inside Tremblaya princeps, which has been maternally transmitted for 100-200 million years. We investigate whether host genotype may influence symbiont density by crossing mealybugs from two inbred laboratory-reared populations that differ substantially in their symbiont density to create hybrids. The density of the M. endobia symbiont in the hybrid hosts matched that of the maternal parent population, in keeping with density being determined either by the symbiont or the maternal genotype. However, the density of the T. princeps symbiont was influenced by the paternal host genotype. The greater dependency of T. princeps on its host may be due to its highly reduced genome. The decoupling of T. princeps and M. endobia densities, in spite of their intimate association, suggests that distinct regulatory mechanisms can be at work in symbiotic partnerships, even when they are obligate and mutualistic. PMID:27099709

  11. Fungal symbiosis from mutualism to parasitism: who controls the outcome, host or invader?

    USGS Publications Warehouse

    Redman, R.S.; Dunigan, D.D.; Rodriguez, R.J.

    2001-01-01

    Plant symbiotic fungi are generally thought to express a single lifestyle that might increase (mutualism), decrease (parasitism), or have no influence (commensalism) on host fitness. However, data are presented here demonstrating that plant pathogenic Colletotrichum species are able to asymptomatically colonize plants and express nonpathogenic lifestyles. Experiments were conducted in growth chambers and plant colonization was assessed by emergence of fungi from surface sterilized plant tissues. Expression of symbiotic lifestyles was assessed by monitoring the ability of fungi to confer disease resistance, drought tolerance and growth enhancement. Several pathogenic Colletotrichum species expressed either mutualistic or commensal lifestyles in plants not known to be hosts. Mutualists conferred disease resistance, drought tolerance, and/or growth enhancement to host plants. Lifestyle-altered mutants expressing nonpathogenic lifestyles had greater host ranges than the parental wildtype isolate. Successive colonization studies indicated that the ability of a symbiont to colonize a plant was dependent on previous colonization events and the lifestyles expressed by the initial colonizing fungus. The results indicate that the outcome of symbiosis is controlled by the plant's physiology. ?? New Phytologist.

  12. 7 CFR 1260.125 - Industry information.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Industry information. 1260.125 Section 1260.125... Promotion and Research Order Definitions § 1260.125 Industry information. Industry information means... efficiency, and activities to enhance the image of the cattle industry....

  13. 7 CFR 1260.125 - Industry information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Industry information. 1260.125 Section 1260.125... Promotion and Research Order Definitions § 1260.125 Industry information. Industry information means... efficiency, and activities to enhance the image of the cattle industry....

  14. 7 CFR 1260.125 - Industry information.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Industry information. 1260.125 Section 1260.125... Promotion and Research Order Definitions § 1260.125 Industry information. Industry information means... efficiency, and activities to enhance the image of the cattle industry....

  15. 7 CFR 1260.125 - Industry information.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Industry information. 1260.125 Section 1260.125... Promotion and Research Order Definitions § 1260.125 Industry information. Industry information means... efficiency, and activities to enhance the image of the cattle industry....

  16. Stress promotes Arabidopsis - Piriformospora indica interaction.

    PubMed

    Vahabi, Khabat; Dorcheh, Sedigheh Karimi; Monajembashi, Shamci; Westermann, Martin; Reichelt, Michael; Falkenberg, Daniela; Hemmerich, Peter; Sherameti, Irena; Oelmüller, Ralf

    2016-05-01

    The endophytic fungus Piriformospora indica colonizes Arabidopsis thaliana roots and promotes plant performance, growth and resistance/tolerance against abiotic and biotic stress. Here we demonstrate that the benefits for the plant increase when the two partners are co-cultivated under stress (limited access to nutrient, exposure to heavy metals and salt, light and osmotic stress, pathogen infection). Moreover, physical contact between P. indica and Arabidopsis roots is necessary for optimal growth promotion, and chemical communication cannot replace the physical contact. Lower nutrient availability down-regulates and higher nutrient availability up-regulates the plant defense system including the expression of pathogenesis-related genes in roots. High light, osmotic and salt stresses support the beneficial interaction between the plant and the fungus. P. indica reduces stomata closure and H2O2 production after Alternaria brassicae infection in leaves and suppresses the defense-related accumulation of the phytohormone jasmonic acid. Thus, shifting the growth conditions toward a stress promotes the mutualistic interaction, while optimal supply with nutrients or low stress diminishes the benefits for the plant in the symbiosis. PMID:27167761

  17. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2003-01-01

    Statistics on the production, consumption, cost, trade, and government stockpile of natural and synthetic industrial diamond are provided. The outlook for the industrial diamond market is also considered.

  18. Identification of genes that regulate phosphate acquisition and plant performance during arbuscular my corrhizal symbiosis in medicago truncatula and brachypodium distachyon

    SciTech Connect

    Harrison, Maria J; Hudson, Matthew E

    2015-11-24

    Most vascular flowering plants have the ability to form symbiotic associations with arbuscular mycorrhizal (AM) fungi. The symbiosis develops in the roots and can have a profound effect on plant productivity, largely through improvements in plant mineral nutrition. Within the root cortical cells, the plant and fungus create novel interfaces specialized for nutrient transfer, while the fungus also develops a network of hyphae in the rhizosphere. Through this hyphal network, the fungus acquires and delivers phosphate and nitrogen to the root. In return, the plant provides the fungus with carbon. In addition, to enhancing plant mineral nutrition, the AM symbiosis has an important role in the carbon cycle, and positive effects on soil health. Here we identified and characterized plant genes involved in the regulation and functioning of the AM symbiosis in Medicago truncatula and Brachypodium distachyon. This included the identification and and characterization of a M. truncatula transcription factors that are required for symbiosis. Additionally, we investigated the molecular basis of functional diversity among AM symbioses in B. distachyon and analysed the transcriptome of Brachypodium distachyon during symbiosis.

  19. Transcript Profiling Coupled with Spatial Expression Analyses Reveals Genes Involved in Distinct Developmental Stages of an Arbuscular Mycorrhizal SymbiosisW⃞

    PubMed Central

    Liu, Jinyuan; Blaylock, Laura A.; Endre, Gabriella; Cho, Jennifer; Town, Christopher D.; VandenBosch, Kathryn A.; Harrison, Maria J.

    2003-01-01

    The formation of symbiotic associations with arbuscular mycorrhizal (AM) fungi is a phenomenon common to the majority of vascular flowering plants. Here, we used cDNA arrays to examine transcript profiles in Medicago truncatula roots during the development of an AM symbiosis with Glomus versiforme and during growth under differing phosphorus nutrient regimes. Three percent of the genes examined showed significant changes in transcript levels during the development of the symbiosis. Most genes showing increased transcript levels in mycorrhizal roots showed no changes in response to high phosphorus, suggesting that alterations in transcript levels during symbiosis were a consequence of the AM fungus rather than a secondary effect of improved phosphorus nutrition. Among the mycorrhiza-induced genes, two distinct temporal expression patterns were evident. Members of one group showed an increase in transcripts during the initial period of contact between the symbionts and a subsequent decrease as the symbiosis developed. Defense- and stress-response genes were a significant component of this group. Genes in the second group showed a sustained increase in transcript levels that correlated with the colonization of the root system. The latter group contained a significant proportion of new genes similar to components of signal transduction pathways, suggesting that novel signaling pathways are activated during the development of the symbiosis. Analysis of the spatial expression patterns of two mycorrhiza-induced genes revealed distinct expression patterns consistent with the hypothesis that gene expression in mycorrhizal roots is signaled by both cell-autonomous and cell-nonautonomous signals. PMID:12953114

  20. Industrial Minerals

    ERIC Educational Resources Information Center

    Bradbury, James C.

    1978-01-01

    The past year is seen as not particularly good for industrial minerals and for industry in general. Environmental concerns continued to trouble the industry with unacceptable asbestos concentrations and chlorofluorocarbon effects on ozone. A halting U.S. economy also affected industrial progress. (MA)

  1. Industry Employment

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2012

    2012-01-01

    This article illustrates projected employment change by industry and industry sector over 2010-20 decade. Workers are grouped into an industry according to the type of good produced or service provided by the establishment for which they work. Industry employment projections are shown in terms of numeric change (growth or decline in the total…

  2. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2000-01-01

    Part of the 1999 Industrial Minerals Review. A review of the state of the global industrial diamond industry in 1999 is presented. World consumption of industrial diamond has increased annually in recent years, with an estimated 500 million carats valued between $650 million and $800 million consumed in 1999. In 1999, the U.S. was the world's largest market for industrial diamond and was also one of the world's main producers; the others were Ireland, Russia, and South Africa. Uses of industrial diamonds are discussed, and prices of natural and synthetic industrial diamond are reported.

  3. Searching for a toxic key to unlock the mystery of anemonefish and anemone symbiosis.

    PubMed

    Nedosyko, Anita M; Young, Jeanne E; Edwards, John W; Burke da Silva, Karen

    2014-01-01

    Twenty-six species of anemonefish of the genera Amphiprion and monospecific Premnas, use only 10 species of anemones as hosts in the wild (Families: Actiniidae, Stichodactylidae and Thalassianthidae). Of these 10 anemone species some are used by multiple species of anemonefish while others have only a single anemonefish symbiont. Past studies have explored the different patterns of usage between anemonefish species and anemone species; however the evolution of this relationship remains unknown and has been little studied over the past decade. Here we reopen the case, comparing the toxicity of crude venoms obtained from anemones that host anemonefish as a way to investigate why some anemone species are used as a host more than others. Specifically, for each anemone species we investigated acute toxicity using Artemia francisca (LC50), haemolytic toxicity using ovine erythrocytes (EC50) and neurotoxicity using shore crabs (Ozius truncatus). We found that haemolytic and neurotoxic activity varied among host anemone species. Generally anemone species that displayed greater haemolytic activity also displayed high neurotoxic activity and tend to be more toxic on average as indicated by acute lethality analysis. An overall venom toxicity ranking for each anemone species was compared with the number of anemonefish species that are known to associate with each anemone species in the wild. Interestingly, anemones with intermediate toxicity had the highest number of anemonefish associates, whereas anemones with either very low or very high toxicity had the fewest anemonefish associates. These data demonstrate that variation in toxicity among host anemone species may be important in the establishment and maintenance of anemonefish anemone symbiosis. PMID:24878777

  4. Evidence that glucose is the major transferred metabolite in dinoflagellate-cnidarian symbiosis.

    PubMed

    Burriesci, Matthew S; Raab, Theodore K; Pringle, John R

    2012-10-01

    Reef-building corals and many other cnidarians are symbiotic with dinoflagellates of the genus Symbiodinium. It has long been known that the endosymbiotic algae transfer much of their photosynthetically fixed carbon to the host and that this can provide much of the host's total energy. However, it has remained unclear which metabolite(s) are directly translocated from the algae into the host tissue. We reexamined this question in the small sea anemone Aiptasia using labeling of intact animals in the light with (13)C-bicarbonate, rapid homogenization and separation of animal and algal fractions, and analysis of metabolite labeling by gas chromatography-mass spectrometry. We found labeled glucose in the animal fraction within 2 min of exposure to (13)C-bicarbonate, whereas no significant labeling of other compounds was observed within the first 10 min. Although considerable previous evidence has suggested that glycerol might be a major translocated metabolite, we saw no significant labeling of glycerol within the first hour, and incubation of intact animals with (13)C-labeled glycerol did not result in a rapid production of (13)C-glucose. In contrast, when Symbiodinium cells freshly isolated from host tissue were exposed to light and (13)C-bicarbonate in the presence of host homogenate, labeled glycerol, but not glucose, was detected in the medium. We also observed early production of labeled glucose, but not glycerol, in three coral species. Taken together, the results suggest that glucose is the major translocated metabolite in dinoflagellate-cnidarian symbiosis and that the release of glycerol from isolated algae may be part of a stress response. PMID:22956249

  5. The effect of nutrients on carbon and nitrogen fixation by the UCYN-A-haptophyte symbiosis.

    PubMed

    Krupke, Andreas; Mohr, Wiebke; LaRoche, Julie; Fuchs, Bernhard M; Amann, Rudolf I; Kuypers, Marcel M M

    2015-07-01

    Symbiotic relationships between phytoplankton and N2-fixing microorganisms play a crucial role in marine ecosystems. The abundant and widespread unicellular cyanobacteria group A (UCYN-A) has recently been found to live symbiotically with a haptophyte. Here, we investigated the effect of nitrogen (N), phosphorus (P), iron (Fe) and Saharan dust additions on nitrogen (N2) fixation and primary production by the UCYN-A-haptophyte association in the subtropical eastern North Atlantic Ocean using nifH expression analysis and stable isotope incubations combined with single-cell measurements. N2 fixation by UCYN-A was stimulated by the addition of Fe and Saharan dust, although this was not reflected in the nifH expression. CO2 fixation by the haptophyte was stimulated by the addition of ammonium nitrate as well as Fe and Saharan dust. Intriguingly, the single-cell analysis using nanometer scale secondary ion mass spectrometry indicates that the increased CO2 fixation by the haptophyte in treatments without added fixed N is likely an indirect result of the positive effect of Fe and/or P on UCYN-A N2 fixation and the transfer of N2-derived N to the haptophyte. Our results reveal a direct linkage between the marine carbon and nitrogen cycles that is fuelled by the atmospheric deposition of dust. The comparison of single-cell rates suggests a tight coupling of nitrogen and carbon transfer that stays balanced even under changing nutrient regimes. However, it appears that the transfer of carbon from the haptophyte to UCYN-A requires a transfer of nitrogen from UCYN-A. This tight coupling indicates an obligate symbiosis of this globally important diazotrophic association. PMID:25535939

  6. Bacterial bioluminescence regulates expression of a host cryptochrome gene in the squid-Vibrio symbiosis.

    PubMed

    Heath-Heckman, Elizabeth A C; Peyer, Suzanne M; Whistler, Cheryl A; Apicella, Michael A; Goldman, William E; McFall-Ngai, Margaret J

    2013-04-02

    The symbiosis between the squid Euprymna scolopes and its luminous symbiont, Vibrio fischeri, is characterized by daily transcriptional rhythms in both partners and daily fluctuations in symbiont luminescence. In this study, we sought to determine whether symbionts affect host transcriptional rhythms. We identified two transcripts in host tissues (E. scolopes cry1 [escry1] and escry2) that encode cryptochromes, proteins that influence circadian rhythms in other systems. Both genes cycled daily in the head of the squid, with a pattern similar to that of other animals, in which expression of certain cry genes is entrained by environmental light. In contrast, escry1 expression cycled in the symbiont-colonized light organ with 8-fold upregulation coincident with the rhythms of bacterial luminescence, which are offset from the day/night light regime. Colonization of the juvenile light organ by symbionts was required for induction of escry1 cycling. Further, analysis with a mutant strain defective in light production showed that symbiont luminescence is essential for cycling of escry1; this defect could be complemented by presentation of exogenous blue light. However, blue-light exposure alone did not induce cycling in nonsymbiotic animals, but addition of molecules of the symbiont cell envelope to light-exposed animals did recover significant cycling activity, showing that light acts in synergy with other symbiont features to induce cycling. While symbiont luminescence may be a character specific to rhythms of the squid-vibrio association, resident microbial partners could similarly influence well-documented daily rhythms in other systems, such as the mammalian gut.

  7. Bacterial Bioluminescence Regulates Expression of a Host Cryptochrome Gene in the Squid-Vibrio Symbiosis

    PubMed Central

    Heath-Heckman, Elizabeth A. C.; Peyer, Suzanne M.; Whistler, Cheryl A.; Apicella, Michael A.; Goldman, William E.; McFall-Ngai, Margaret J.

    2013-01-01

    ABSTRACT The symbiosis between the squid Euprymna scolopes and its luminous symbiont, Vibrio fischeri, is characterized by daily transcriptional rhythms in both partners and daily fluctuations in symbiont luminescence. In this study, we sought to determine whether symbionts affect host transcriptional rhythms. We identified two transcripts in host tissues (E. scolopes cry1 [escry1] and escry2) that encode cryptochromes, proteins that influence circadian rhythms in other systems. Both genes cycled daily in the head of the squid, with a pattern similar to that of other animals, in which expression of certain cry genes is entrained by environmental light. In contrast, escry1 expression cycled in the symbiont-colonized light organ with 8-fold upregulation coincident with the rhythms of bacterial luminescence, which are offset from the day/night light regime. Colonization of the juvenile light organ by symbionts was required for induction of escry1 cycling. Further, analysis with a mutant strain defective in light production showed that symbiont luminescence is essential for cycling of escry1; this defect could be complemented by presentation of exogenous blue light. However, blue-light exposure alone did not induce cycling in nonsymbiotic animals, but addition of molecules of the symbiont cell envelope to light-exposed animals did recover significant cycling activity, showing that light acts in synergy with other symbiont features to induce cycling. While symbiont luminescence may be a character specific to rhythms of the squid-vibrio association, resident microbial partners could similarly influence well-documented daily rhythms in other systems, such as the mammalian gut. PMID:23549919

  8. A Novel Inducer of Roseobacter Motility Is Also a Disruptor of Algal Symbiosis

    PubMed Central

    Sule, Preeti

    2013-01-01

    Silicibacter sp. strain TM1040, a member of the Roseobacter clade, forms a symbiosis with unicellular phytoplankton, which is inextricably linked to the biphasic “swim or stick” lifestyle of the bacteria. Mutations in flaC bias the population toward the motile phase. Renewed examination of the FlaC− strain (HG1016) uncovered that it is composed of two different cells: a pigmented type, PS01, and a nonpigmented cell, PS02, each of which has an identical mutation in flaC. While monocultures of PS01 and PS02 had few motile cells (0.6 and 6%, respectively), coculturing the two strains resulted in a 10-fold increase in the number of motile cells. Cell-free supernatants from coculture or wild-type cells were fully capable of restoring motility to PS01 and PS02, which was due to increased fliC3 (flagellin) transcription, FliC3 protein levels per cell, and flagella synthesis. The motility-inducing compound has an estimated mass of 226 Da, as determined by mass spectrometry, and is referred to as Roseobacter Motility Inducer (RMI). Mutations affecting genes involved in phenyl acetic acid synthesis significantly reduced RMI, while defects in tropodithietic acid (TDA) synthesis had marginal or no effect on RMI. RMI biosynthesis is induced by p-coumaric acid, a product of algal lignin degradation. When added to algal cultures, RMI caused loss of motility, cell enlargement, and vacuolization in the algal cells. RMI is a new member of the roseobacticide family of troponoid compounds whose activities affect roseobacters, by shifting their population toward motility, as well as their phytoplankton hosts, through an algicidal effect. PMID:23161030

  9. Arbuscular mycorrhizal symbiosis modulates antioxidant response in salt-stressed Trigonella foenum-graecum plants.

    PubMed

    Evelin, Heikham; Kapoor, Rupam

    2014-04-01

    An experiment was conducted to evaluate the influence of Glomus intraradices colonization on the activity of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), peroxidase (PX), ascorbate peroxidase (APX), and glutathione reductase (GR)] and the accumulation of nonenzymatic antioxidants (ascorbic acid, α-tocopherol, glutathione, and carotenoids) in roots and leaves of fenugreek plants subjected to varying degrees of salinity (0, 50, 100, and 200 mM NaCl) at two time intervals (1 and 14 days after saline treatment, DAT). The antioxidative capacity was correlated with oxidative damage in the same tissue. Under salt stress, lipid peroxidation and H2O2 concentration increased with increasing severity and duration of salt stress (DoS). However, the extent of oxidative damage in mycorrhizal plants was less compared to nonmycorrhizal plants. The study reveals that mycorrhiza-mediated attenuation of oxidative stress in fenugreek plants is due to enhanced activity of antioxidant enzymes and higher concentrations of antioxidant molecules. However, the significant effect of G. intraradices colonization on individual antioxidant molecules and enzymes varied with plant tissue, salinity level, and DoS. The significant effect of G. intraradices colonization on antioxidative enzymes was more evident at 1DAT in both leaves and roots, while the concentrations of antioxidant molecules were significantly influenced at 14DAT. It is proposed that AM symbiosis can improve antioxidative defense systems of plants through higher SOD activity in M plants, facilitating rapid dismutation of O2 (-) to H2O2, and subsequent prevention of H2O2 build-up by higher activities of CAT, APX, and PX. The potential of G. intraradices to ameliorate oxidative stress generated in fenugreek plants by salinity was more evident at higher intensities of salt stress.

  10. Trehalose Is a Chemical Attractant in the Establishment of Coral Symbiosis

    PubMed Central

    Hagedorn, Mary; Carter, Virginia; Zuchowicz, Nikolas; Phillips, Micaiah; Penfield, Chelsea; Shamenek, Brittany; Vallen, Elizabeth A.; Kleinhans, Frederick W.; Peterson, Kelly; White, Meghan; Yancey, Paul H.

    2015-01-01

    Coral reefs have evolved with a crucial symbiosis between photosynthetic dinoflagellates (genus Symbiodinium) and their cnidarian hosts (Scleractinians). Most coral larvae take up Symbiodinium from their environment; however, the earliest steps in this process have been elusive. Here we demonstrate that the disaccharide trehalose may be an important signal from the symbiont to potential larval hosts. Symbiodinium freshly isolated from Fungia scutaria corals constantly released trehalose (but not sucrose, maltose or glucose) into seawater, and released glycerol only in the presence of coral tissue. Spawning Fungia adults increased symbiont number in their immediate area by excreting pellets of Symbiodinium, and when these naturally discharged Symbiodinium were cultured, they also released trehalose. In Y-maze experiments, coral larvae demonstrated chemoattractant and feeding behaviors only towards a chamber with trehalose or glycerol. Concomitantly, coral larvae and adult tissue, but not symbionts, had significant trehalase enzymatic activities, suggesting the capacity to utilize trehalose. Trehalase activity was developmentally regulated in F. scutaria larvae, rising as the time for symbiont uptake occurs. Consistent with the enzymatic assays, gene finding demonstrated the presence of a trehalase enzyme in the genome of a related coral, Acropora digitifera, and a likely trehalase in the transcriptome of F. scutaria. Taken together, these data suggest that adult F. scutaria seed the reef with Symbiodinium during spawning and the exuded Symbiodinium release trehalose into the environment, which acts as a chemoattractant for F. scutaria larvae and as an initiator of feeding behavior- the first stages toward establishing the coral-Symbiodinium relationship. Because trehalose is a fixed carbon compound, this cue would accurately demonstrate to the cnidarian larvae the photosynthetic ability of the potential symbiont in the ambient environment. To our knowledge, this is

  11. Disruption of Signaling in a Fungal-Grass Symbiosis Leads to Pathogenesis1[W][OA

    PubMed Central

    Eaton, Carla J.; Cox, Murray P.; Ambrose, Barbara; Becker, Matthias; Hesse, Uljana; Schardl, Christopher L.; Scott, Barry

    2010-01-01

    Symbiotic associations between plants and fungi are a dominant feature of many terrestrial ecosystems, yet relatively little is known about the signaling, and associated transcriptome profiles, that define the symbiotic metabolic state. Using the Epichloë festucae-perennial ryegrass (Lolium perenne) association as a model symbiotic experimental system, we show an essential role for the fungal stress-activated mitogen-activated protein kinase (sakA) in the establishment and maintenance of this mutualistic interaction. Deletion of sakA switches the fungal interaction with the host from mutualistic to pathogenic. Infected plants exhibit loss of apical dominance, premature senescence, and dramatic changes in development, including the formation of bulb-like structures at the base of tillers that lack anthocyanin pigmentation. A comparison of the transcriptome of wild-type and sakA associations using high-throughput mRNA sequencing reveals dramatic changes in fungal gene expression consistent with the transition from restricted to proliferative growth, including a down-regulation of several clusters of secondary metabolite genes and up-regulation of a large set of genes that encode hydrolytic enzymes and transporters. Analysis of the plant transcriptome reveals up-regulation of host genes involved in pathogen defense and transposon activation as well as dramatic changes in anthocyanin and hormone biosynthetic/responsive gene expression. These results highlight the fine balance between mutualism and antagonism in a plant-fungal interaction and the power of deep mRNA sequencing to identify candidate sets of genes underlying the symbiosis. PMID:20519633

  12. Recognition in a Social Symbiosis: Chemical Phenotypes and Nestmate Recognition Behaviors of Neotropical Parabiotic Ants

    PubMed Central

    Emery, Virginia J.; Tsutsui, Neil D.

    2013-01-01

    Social organisms rank among the most abundant and ecologically dominant species on Earth, in part due to exclusive recognition systems that allow cooperators to be distinguished from exploiters. Exploiters, such as social parasites, manipulate their hosts’ recognition systems, whereas cooperators are expected to minimize interference with their partner’s recognition abilities. Despite our wealth of knowledge about recognition in single-species social nests, less is known of the recognition systems in multi-species nests, particularly involving cooperators. One uncommon type of nesting symbiosis, called parabiosis, involves two species of ants sharing a nest and foraging trails in ostensible cooperation. Here, we investigated recognition cues (cuticular hydrocarbons) and recognition behaviors in the parabiotic mixed-species ant nests of Camponotus femoratus and Crematogaster levior in North-Eastern Amazonia. We found two sympatric, cryptic Cr. levior chemotypes in the population, with one type in each parabiotic colony. Although they share a nest, very few hydrocarbons were shared between Ca. femoratus and either Cr. levior chemotype. The Ca. femoratus hydrocarbons were also unusually long–chained branched alkenes and dienes, compounds not commonly found amongst ants. Despite minimal overlap in hydrocarbon profile, there was evidence of potential interspecific nestmate recognition –Cr. levior ants were more aggressive toward Ca. femoratus non-nestmates than Ca. femoratus nestmates. In contrast to the prediction that sharing a nest could weaken conspecific recognition, each parabiotic species also maintains its own aggressive recognition behaviors to exclude conspecific non-nestmates. This suggests that, despite cohabitation, parabiotic ants maintain their own species-specific colony odors and recognition mechanisms. It is possible that such social symbioses are enabled by the two species each using their own separate recognition cues, and that interspecific

  13. The effect of nutrients on carbon and nitrogen fixation by the UCYN-A–haptophyte symbiosis

    PubMed Central

    Krupke, Andreas; Mohr, Wiebke; LaRoche, Julie; Fuchs, Bernhard M; Amann, Rudolf I; Kuypers, Marcel MM

    2015-01-01

    Symbiotic relationships between phytoplankton and N2-fixing microorganisms play a crucial role in marine ecosystems. The abundant and widespread unicellular cyanobacteria group A (UCYN-A) has recently been found to live symbiotically with a haptophyte. Here, we investigated the effect of nitrogen (N), phosphorus (P), iron (Fe) and Saharan dust additions on nitrogen (N2) fixation and primary production by the UCYN-A–haptophyte association in the subtropical eastern North Atlantic Ocean using nifH expression analysis and stable isotope incubations combined with single-cell measurements. N2 fixation by UCYN-A was stimulated by the addition of Fe and Saharan dust, although this was not reflected in the nifH expression. CO2 fixation by the haptophyte was stimulated by the addition of ammonium nitrate as well as Fe and Saharan dust. Intriguingly, the single-cell analysis using nanometer scale secondary ion mass spectrometry indicates that the increased CO2 fixation by the haptophyte in treatments without added fixed N is likely an indirect result of the positive effect of Fe and/or P on UCYN-A N2 fixation and the transfer of N2-derived N to the haptophyte. Our results reveal a direct linkage between the marine carbon and nitrogen cycles that is fuelled by the atmospheric deposition of dust. The comparison of single-cell rates suggests a tight coupling of nitrogen and carbon transfer that stays balanced even under changing nutrient regimes. However, it appears that the transfer of carbon from the haptophyte to UCYN-A requires a transfer of nitrogen from UCYN-A. This tight coupling indicates an obligate symbiosis of this globally important diazotrophic association. PMID:25535939

  14. Specificity is rarely absolute in coral-algal symbiosis: implications for coral response to climate change.

    PubMed

    Silverstein, Rachel N; Correa, Adrienne M S; Baker, Andrew C

    2012-07-01

    Some reef-building corals have been shown to respond to environmental change by shifting the composition of their algal symbiont (genus Symbiodinium) communities. These shifts have been proposed as a potential mechanism by which corals might survive climate stressors, such as increased temperatures. Conventional molecular methods suggest this adaptive capacity may not be widespread because few (∼25%) coral species have been found to associate with multiple Symbiodinium clades. However, these methods can fail to detect low abundance symbionts (typically less than 10-20% of the total algal symbiont community). To determine whether additional Symbiodinium clades are present, but are not detected using conventional techniques, we applied a high-resolution, real-time PCR assay to survey Symbiodinium (in clades A-D) from 39 species of phylogenetically and geographically diverse scleractinian corals. This survey included 26 coral species thought to be restricted to hosting a single Symbiodinium clade ('symbiotic specialists'). We detected at least two Symbiodinium clades (C and D) in at least one sample of all 39 coral species tested; all four Symbiodinium clades were detected in over half (54%) of the 26 symbiotic specialist coral species. Furthermore, on average, 68 per cent of all sampled colonies within a given coral species hosted two or more symbiont clades. We conclude that the ability to associate with multiple symbiont clades is common in scleractinian (stony) corals, and that, in coral-algal symbiosis, 'specificity' and 'flexibility' are relative terms: specificity is rarely absolute. The potential for reef corals to adapt or acclimatize to environmental change via symbiont community shifts may therefore be more phylogenetically widespread than has previously been assumed.

  15. Mycorrhizal symbiosis and local adaptation in Aster amellus: a field transplant experiment.

    PubMed

    Pánková, Hana; Raabová, Jana; Münzbergová, Zuzana

    2014-01-01

    Many plant populations have adapted to local soil conditions. However, the role of arbuscular mycorrhizal fungi is often overlooked in this context. Only a few studies have used reciprocal transplant experiments to study the relationships between soil conditions, mycorrhizal colonisation and plant growth. Furthermore, most of the studies were conducted under controlled greenhouse conditions. However, long-term field experiments can provide more realistic insights into this issue. We conducted a five-year field reciprocal transplant experiment to study the relationships between soil conditions, arbuscular mycorrhizal fungi and plant growth in the obligate mycotrophic herb Aster amellus. We conducted this study in two regions in the Czech Republic that differ significantly in their soil nutrient content, namely Czech Karst (region K) and Ceske Stredohori (region S). Plants that originated from region S had significantly higher mycorrhizal colonisation than plants from region K, indicating that the percentage of mycorrhizal colonisation has a genetic basis. We found no evidence of local adaptation in Aster amellus. Instead, plants from region S outperformed the plants from region K in both target regions. Similarly, plants from region S showed more mycorrhizal colonisation in all cases, which was likely driven by the lower nutrient content in the soil from that region. Thus, plant aboveground biomass and mycorrhizal colonisation exhibited corresponding differences between the two target regions and regions of origin. Higher mycorrhizal colonisation in the plants from region with lower soil nutrient content (region S) in both target regions indicates that mycorrhizal colonisation is an adaptive trait. However, lower aboveground biomass in the plants with lower mycorrhizal colonisation suggests that the plants from region K are in fact maladapted by their low inherent mycorrhizal colonization. We conclude that including mycorrhizal symbiosis in local adaptation studies

  16. Effects of the Epichloë fungal endophyte symbiosis with Schedonorus pratensis on host grass invasiveness

    PubMed Central

    Shukla, Kruti; Hager, Heather A; Yurkonis, Kathryn A; Newman, Jonathan A

    2015-01-01

    Initial studies of grass–endophyte mutualisms using Schedonorus arundinaceus cultivar Kentucky-31 infected with the vertically transmitted endophyte Epichloë coenophiala found strong, positive endophyte effects on host-grass invasion success. However, more recent work using different cultivars of S. arundinaceus has cast doubt on the ubiquity of this effect, at least as it pertains to S. arundinaceus–E. coenophiala. We investigated the generality of previous work on vertically transmitted Epichloë-associated grass invasiveness by studying a pair of very closely related species: S. pratensis and E. uncinata. Seven cultivars of S. pratensis and two cultivars of S. arundinaceus that were developed with high- or low-endophyte infection rate were broadcast seeded into 2 × 2-m plots in a tilled, old-field grassland community in a completely randomized block design. Schedonorus abundance, endophyte infection rate, and co-occurring vegetation were sampled 3, 4, 5, and 6 years after establishment, and the aboveground invertebrate community was sampled in S. pratensis plots 3 and 4 years after establishment. Endophyte infection did not enable the host grass to achieve high abundance in the plant community. Contrary to expectations, high-endophyte S. pratensis increased plant richness relative to low-endophyte cultivars. However, as expected, high-endophyte S. pratensis marginally decreased invertebrate taxon richness. Endophyte effects on vegetation and invertebrate community composition were inconsistent among cultivars and were weaker than temporal effects. The effect of the grass–Epichloë symbiosis on diversity is not generalizable, but rather specific to species, cultivar, infection, and potentially site. Examining grass–endophyte systems using multiple cultivars and species replicated among sites will be important to determine the range of conditions in which endophyte associations benefit host grass performance and have subsequent effects on

  17. Understanding the role of host hemocytes in a squid/vibrio symbiosis using transcriptomics and proteomics.

    PubMed

    Collins, Andrew J; Schleicher, Tyler R; Rader, Bethany A; Nyholm, Spencer V

    2012-01-01

    The symbiosis between the squid, Euprymna scolopes, and the bacterium, Vibrio fischeri, serves as a model for understanding interactions between beneficial bacteria and animal hosts. The establishment and maintenance of the association is highly specific and depends on the selection of V. fischeri and exclusion of non-symbiotic bacteria from the environment. Current evidence suggests that the host's cellular innate immune system, in the form of macrophage-like hemocytes, helps to mediate host tolerance of V. fischeri. To begin to understand the role of hemocytes in this association, we analyzed these cells by high-throughput 454 transcriptomic and liquid chromatography/tandem mass spectrometry (LC-MS/MS) proteomic analyses. 454 high-throughput sequencing produced 650, 686 reads totaling 279.9 Mb while LC-MS/MS analyses of circulating hemocytes putatively identified 702 unique proteins. Several receptors involved with the recognition of microbial-associated molecular patterns were identified. Among these was a complete open reading frame to a putative peptidoglycan recognition protein (EsPGRP5) with conserved residues for amidase activity. Assembly of the hemocyte transcriptome showed EsPGRP5 had high coverage, suggesting it is among the 5% most abundant transcripts in circulating hemocytes. Other transcripts and proteins identified included members of the conserved NF-κB signaling pathway, putative members of the complement pathway, the carbohydrate binding protein galectin, and cephalotoxin. Quantitative Real-Time PCR of complement-like genes, cephalotoxin, EsPGRP5, and a nitric oxide synthase showed differential expression in circulating hemocytes from adult squid with colonized light organs compared to those isolated from hosts where the symbionts were removed. These data suggest that the presence of the symbiont influences gene expression of the cellular innate immune system of E. scolopes. PMID:22590467

  18. Crosstalk of Signaling Mechanisms Involved in Host Defense and Symbiosis Against Microorganisms in Rice.

    PubMed

    Akamatsu, Akira; Shimamoto, Ko; Kawano, Yoji

    2016-08-01

    Rice is one of the most important food crops, feeding about half population in the world. Rice pathogens cause enormous damage to rice production worldwide. In plant immunity research, considerable progress has recently been made in our understanding of the molecular mechanisms underlying microbe-associated molecular pattern (MAMP)-triggered immunity. Using genome sequencing and molecular techniques, a number of new MAMPs and their receptors have been identified in the past two decades. Notably, the mechanisms for chitin perception via the lysine motif (LysM) domain-containing receptor OsCERK1, as well as the mechanisms for bacterial MAMP (e.g. flg22, elf18) perception via the leucine-rich repeat (LRR) domain-containing receptors FLS2 and EFR, have been clarified in rice and Arabidopsis, respectively. In chitin signaling in rice, two direct substrates of OsCERK1, Rac/ROP GTPase guanine nucleotide exchange factor OsRacGEF1 and receptor-like cytoplasmic kinase OsRLCK185, have been identified as components of the OsCERK1 complex and are rapidly phosphorylated by OsCERK1 in response to chitin. Interestingly, OsCERK1 also participates in symbiosis with arbuscular mycorrhizal fungi (AMF) in rice and plays a role in the recognition of short-chitin molecules (CO4/5), which are symbiotic signatures included in AMF germinated spore exudates and induced by synthetic strigolactone. Thus, OsCERK1 contributes to both immunity and symbiotic responses. In this review, we describe recent studies on pathways involved in rice immunity and symbiotic signaling triggered by interactions with microorganisms. In addition, we describe recent advances in genetic engineering by using plant immune receptors and symbiotic microorganisms to enhance disease resistance of rice. PMID:27499679

  19. Specificity is rarely absolute in coral–algal symbiosis: implications for coral response to climate change

    PubMed Central

    Silverstein, Rachel N.; Correa, Adrienne M. S.; Baker, Andrew C.

    2012-01-01

    Some reef-building corals have been shown to respond to environmental change by shifting the composition of their algal symbiont (genus Symbiodinium) communities. These shifts have been proposed as a potential mechanism by which corals might survive climate stressors, such as increased temperatures. Conventional molecular methods suggest this adaptive capacity may not be widespread because few (∼25%) coral species have been found to associate with multiple Symbiodinium clades. However, these methods can fail to detect low abundance symbionts (typically less than 10–20% of the total algal symbiont community). To determine whether additional Symbiodinium clades are present, but are not detected using conventional techniques, we applied a high-resolution, real-time PCR assay to survey Symbiodinium (in clades A–D) from 39 species of phylogenetically and geographically diverse scleractinian corals. This survey included 26 coral species thought to be restricted to hosting a single Symbiodinium clade (‘symbiotic specialists’). We detected at least two Symbiodinium clades (C and D) in at least one sample of all 39 coral species tested; all four Symbiodinium clades were detected in over half (54%) of the 26 symbiotic specialist coral species. Furthermore, on average, 68 per cent of all sampled colonies within a given coral species hosted two or more symbiont clades. We conclude that the ability to associate with multiple symbiont clades is common in scleractinian (stony) corals, and that, in coral–algal symbiosis, ‘specificity’ and ‘flexibility’ are relative terms: specificity is rarely absolute. The potential for reef corals to adapt or acclimatize to environmental change via symbiont community shifts may therefore be more phylogenetically widespread than has previously been assumed. PMID:22367985

  20. Ontogenetic shifts in a freshwater cleaning symbiosis: consequences for hosts and their symbionts.

    PubMed

    Thomas, Michael J; Creed, Robert P; Skelton, James; Brown, Bryan L

    2016-06-01

    Animal fitness is influenced by diverse assemblages of internal and external symbionts. These assemblages often change throughout host ontogeny, but the mechanisms that underlie these changes and their consequences for host fitness are seldom revealed. Here we examine a cleaning symbiosis between crayfish and an assemblage of ectosymbiotic branchiobdellidan worms to uncover what mechanisms drive changes in symbiont composition during host ontogeny and the consequences of these changes for both the host and symbionts. In surveys of a North Carolina river, the dominant worm species shifted from Cambarincola philadelphicus to Cambarincola ingens as crayfish (Cambarus bartonii) increased in size. We demonstrate that this shift is a function of host regulation by small crayfish and exclusion by a dominant symbiont on large crayfish. In a controlled lab experiment, small crayfish often removed their symbionts but C. ingens was removed at a higher rate than C. philadelphicus. In contrast, C. ingens had higher survivorship and reproduction than C. philadelphicus on large crayfish. We also measured the effect of each worm species on crayfish growth through ontogeny; neither worm species had an effect on small crayfish but both species had similar positive effects on the growth of large crayfish relative to controls. Evidence from another experiment suggested that intraguild predation by C. ingens caused a decline in C. philadelphicus on large crayfish. We have shown that shifts in partner fitness are a function of host size and that these shifts can involve the succession of symbionts. Further, our results suggest that changes in the outcome of symbioses can remain robust throughout host ontogeny despite interactive mechanisms that lead to shifts in symbiont community structure.

  1. Evolutionary dynamics of nitrogen fixation in the legume-rhizobia symbiosis.

    PubMed

    Fujita, Hironori; Aoki, Seishiro; Kawaguchi, Masayoshi

    2014-01-01

    The stabilization of host-symbiont mutualism against the emergence of parasitic individuals is pivotal to the evolution of cooperation. One of the most famous symbioses occurs between legumes and their colonizing rhizobia, in which rhizobia extract nutrients (or benefits) from legume plants while supplying them with nitrogen resources produced by nitrogen fixation (or costs). Natural environments, however, are widely populated by ineffective rhizobia that extract benefits without paying costs and thus proliferate more efficiently than nitrogen-fixing cooperators. How and why this mutualism becomes stabilized and evolutionarily persists has been extensively discussed. To better understand the evolutionary dynamics of this symbiosis system, we construct a simple model based on the continuous snowdrift game with multiple interacting players. We investigate the model using adaptive dynamics and numerical simulations. We find that symbiotic evolution depends on the cost-benefit balance, and that cheaters widely emerge when the cost and benefit are similar in strength. In this scenario, the persistence of the symbiotic system is compatible with the presence of cheaters. This result suggests that the symbiotic relationship is robust to the emergence of cheaters, and may explain the prevalence of cheating rhizobia in nature. In addition, various stabilizing mechanisms, such as partner fidelity feedback, partner choice, and host sanction, can reinforce the symbiotic relationship by affecting the fitness of symbionts in various ways. This result suggests that the symbiotic relationship is cooperatively stabilized by various mechanisms. In addition, mixed nodule populations are thought to encourage cheater emergence, but our model predicts that, in certain situations, cheaters can disappear from such populations. These findings provide a theoretical basis of the evolutionary dynamics of legume-rhizobia symbioses, which is extendable to other single-host, multiple

  2. The effect of nutrients on carbon and nitrogen fixation by the UCYN-A-haptophyte symbiosis.

    PubMed

    Krupke, Andreas; Mohr, Wiebke; LaRoche, Julie; Fuchs, Bernhard M; Amann, Rudolf I; Kuypers, Marcel M M

    2015-07-01

    Symbiotic relationships between phytoplankton and N2-fixing microorganisms play a crucial role in marine ecosystems. The abundant and widespread unicellular cyanobacteria group A (UCYN-A) has recently been found to live symbiotically with a haptophyte. Here, we investigated the effect of nitrogen (N), phosphorus (P), iron (Fe) and Saharan dust additions on nitrogen (N2) fixation and primary production by the UCYN-A-haptophyte association in the subtropical eastern North Atlantic Ocean using nifH expression analysis and stable isotope incubations combined with single-cell measurements. N2 fixation by UCYN-A was stimulated by the addition of Fe and Saharan dust, although this was not reflected in the nifH expression. CO2 fixation by the haptophyte was stimulated by the addition of ammonium nitrate as well as Fe and Saharan dust. Intriguingly, the single-cell analysis using nanometer scale secondary ion mass spectrometry indicates that the increased CO2 fixation by the haptophyte in treatments without added fixed N is likely an indirect result of the positive effect of Fe and/or P on UCYN-A N2 fixation and the transfer of N2-derived N to the haptophyte. Our results reveal a direct linkage between the marine carbon and nitrogen cycles that is fuelled by the atmospheric deposition of dust. The comparison of single-cell rates suggests a tight coupling of nitrogen and carbon transfer that stays balanced even under changing nutrient regimes. However, it appears that the transfer of carbon from the haptophyte to UCYN-A requires a transfer of nitrogen from UCYN-A. This tight coupling indicates an obligate symbiosis of this globally important diazotrophic association.

  3. Ontogenetic shifts in a freshwater cleaning symbiosis: consequences for hosts and their symbionts.

    PubMed

    Thomas, Michael J; Creed, Robert P; Skelton, James; Brown, Bryan L

    2016-06-01

    Animal fitness is influenced by diverse assemblages of internal and external symbionts. These assemblages often change throughout host ontogeny, but the mechanisms that underlie these changes and their consequences for host fitness are seldom revealed. Here we examine a cleaning symbiosis between crayfish and an assemblage of ectosymbiotic branchiobdellidan worms to uncover what mechanisms drive changes in symbiont composition during host ontogeny and the consequences of these changes for both the host and symbionts. In surveys of a North Carolina river, the dominant worm species shifted from Cambarincola philadelphicus to Cambarincola ingens as crayfish (Cambarus bartonii) increased in size. We demonstrate that this shift is a function of host regulation by small crayfish and exclusion by a dominant symbiont on large crayfish. In a controlled lab experiment, small crayfish often removed their symbionts but C. ingens was removed at a higher rate than C. philadelphicus. In contrast, C. ingens had higher survivorship and reproduction than C. philadelphicus on large crayfish. We also measured the effect of each worm species on crayfish growth through ontogeny; neither worm species had an effect on small crayfish but both species had similar positive effects on the growth of large crayfish relative to controls. Evidence from another experiment suggested that intraguild predation by C. ingens caused a decline in C. philadelphicus on large crayfish. We have shown that shifts in partner fitness are a function of host size and that these shifts can involve the succession of symbionts. Further, our results suggest that changes in the outcome of symbioses can remain robust throughout host ontogeny despite interactive mechanisms that lead to shifts in symbiont community structure. PMID:27459781

  4. Understanding the Role of Host Hemocytes in a Squid/Vibrio Symbiosis Using Transcriptomics and Proteomics

    PubMed Central

    Collins, Andrew J.; Schleicher, Tyler R.; Rader, Bethany A.; Nyholm, Spencer V.

    2012-01-01

    The symbiosis between the squid, Euprymna scolopes, and the bacterium, Vibrio fischeri, serves as a model for understanding interactions between beneficial bacteria and animal hosts. The establishment and maintenance of the association is highly specific and depends on the selection of V. fischeri and exclusion of non-symbiotic bacteria from the environment. Current evidence suggests that the host’s cellular innate immune system, in the form of macrophage-like hemocytes, helps to mediate host tolerance of V. fischeri. To begin to understand the role of hemocytes in this association, we analyzed these cells by high-throughput 454 transcriptomic and liquid chromatography/tandem mass spectrometry (LC-MS/MS) proteomic analyses. 454 high-throughput sequencing produced 650, 686 reads totaling 279.9 Mb while LC-MS/MS analyses of circulating hemocytes putatively identified 702 unique proteins. Several receptors involved with the recognition of microbial-associated molecular patterns were identified. Among these was a complete open reading frame to a putative peptidoglycan recognition protein (EsPGRP5) with conserved residues for amidase activity. Assembly of the hemocyte transcriptome showed EsPGRP5 had high coverage, suggesting it is among the 5% most abundant transcripts in circulating hemocytes. Other transcripts and proteins identified included members of the conserved NF-κB signaling pathway, putative members of the complement pathway, the carbohydrate binding protein galectin, and cephalotoxin. Quantitative Real-Time PCR of complement-like genes, cephalotoxin, EsPGRP5, and a nitric oxide synthase showed differential expression in circulating hemocytes from adult squid with colonized light organs compared to those isolated from hosts where the symbionts were removed. These data suggest that the presence of the symbiont influences gene expression of the cellular innate immune system of E. scolopes. PMID:22590467

  5. Abscisic Acid Promotion of Arbuscular Mycorrhizal Colonization Requires a Component of the PROTEIN PHOSPHATASE 2A Complex1[W][OPEN

    PubMed Central

    Charpentier, Myriam; Sun, Jongho; Wen, Jiangqi; Mysore, Kirankumar S.; Oldroyd, Giles E.D.

    2014-01-01

    Legumes can establish intracellular interactions with symbiotic microbes to enhance their fitness, including the interaction with arbuscular mycorrhizal (AM) fungi. AM fungi colonize root epidermal cells to gain access to the root cortex, and this requires the recognition by the host plant of fungus-made mycorrhizal factors. Genetic dissection has revealed the symbiosis signaling pathway that allows the recognition of AM fungi, but the downstream processes that are required to promote fungal infection are poorly understood. Abscisic acid (ABA) has been shown to promote arbuscule formation in tomato (Solanum lycopersicum). Here, we show that ABA modulates the establishment of the AM symbiosis in Medicago truncatula by promoting fungal colonization at low concentrations and impairing it at high concentrations. We show that the positive regulation of AM colonization via ABA requires a PROTEIN PHOSPHATASE 2A (PP2A) holoenzyme subunit, PP2AB′1. Mutations in PP2AB′1 cause reduced levels of AM colonization that cannot be rescued with permissive ABA application. The action of PP2AB′1 in response to ABA is unlinked to the generation of calcium oscillations, as the pp2aB′1 mutant displays a normal calcium response. This contrasts with the application of high concentrations of ABA that impairs mycorrhizal factor-induced calcium oscillations, suggesting different modes of action of ABA on the AM symbiosis. Our work reveals that ABA functions at multiple levels to regulate the AM symbiosis and that a PP2A phosphatase is required for the ABA promotion of AM colonization. PMID:25293963

  6. Metabolite profiling of symbiont and host during thermal stress and bleaching in a model cnidarian-dinoflagellate symbiosis.

    PubMed

    Hillyer, Katie E; Tumanov, Sergey; Villas-Bôas, Silas; Davy, Simon K

    2016-02-01

    Bleaching (dinoflagellate symbiont loss) is one of the greatest threats facing coral reefs. The functional cnidarian-dinoflagellate symbiosis, which forms coral reefs, is based on the bi-directional exchange of nutrients. During thermal stress this exchange breaks down; however, major gaps remain in our understanding of the roles of free metabolite pools in symbiosis and homeostasis. In this study we applied gas chromatography-mass spectrometry (GC-MS) to explore thermally induced changes in intracellular pools of amino and non-amino organic acids in each partner of the model sea anemone Aiptasia sp. and its dinoflagellate symbiont. Elevated temperatures (32 °C for 6 days) resulted in symbiont photoinhibition and bleaching. Thermal stress induced distinct changes in the metabolite profiles of both partners, associated with alterations to central metabolism, oxidative state, cell structure, biosynthesis and signalling. Principally, we detected elevated pools of polyunsaturated fatty acids (PUFAs) in the symbiont, indicative of modifications to lipogenesis/lysis, membrane structure and nitrogen assimilation. In contrast, reductions of multiple PUFAs were detected in host pools, indicative of increased metabolism, peroxidation and/or reduced translocation of these groups. Accumulations of glycolysis intermediates were also observed in both partners, associated with photoinhibition and downstream reductions in carbohydrate metabolism. Correspondingly, we detected accumulations of amino acids and intermediate groups in both partners, with roles in gluconeogenesis and acclimation responses to oxidative stress. These data further our understanding of cellular responses to thermal stress in the symbiosis and generate hypotheses relating to the secondary roles of a number of compounds in homeostasis and heat-stress resistance. PMID:26685173

  7. EXO70I Is Required for Development of a Sub-domain of the Periarbuscular Membrane during Arbuscular Mycorrhizal Symbiosis.

    PubMed

    Zhang, Xinchun; Pumplin, Nathan; Ivanov, Sergey; Harrison, Maria J

    2015-08-17

    In eukaryotic cells, polarized secretion mediated by exocytotic fusion of membrane vesicles with the plasma membrane is essential for spatially restricted expansion of the plasma membrane and for the delivery of molecules to specific locations at the membrane and/or cell surface. The EXOCYST complex is central to this process, and in yeast, regulation of the EXO70 subunit influences exocytosis and cargo specificity. In contrast to yeast and mammalian cells, plants have upwards of 23 EXO70 genes with largely unknown roles. During arbuscular mycorrhizal (AM) symbiosis, deposition of the plant periarbuscular membrane (PAM) around the fungal arbuscule creates an intracellular membrane interface between the symbionts. The PAM has two major membrane sub-domains, and symbiosis-specific transporter proteins are localized in the branch domain. Currently, the mechanisms and cellular machinery involved in biogenesis of the PAM are largely unknown. Here, we identify an EXO70I protein present exclusively in plants forming AM symbiosis. Medicago truncatula exo70i mutants are unable to support normal arbuscule development, and incorporation of two PAM-resident ABC transporters, STR and STR2, is limited. During arbuscule branching, EXO70I is located in spatially restricted zones adjacent to the PAM around the arbuscule hyphal tips where it interacts with Vapyrin, a plant-specific protein required for arbuscule development. We conclude that EXO70I provides a specific exocytotic capacity necessary for development of the main functional sub-domain of the PAM. Furthermore, in contrast to other eukaryotes, plant EXO70s have evolved distinct specificities and interaction partners to fulfill their specialized secretory requirements.

  8. Genome-Wide Functional Divergence after the Symbiosis of Proteobacteria with Insects Unraveled through a Novel Computational Approach

    PubMed Central

    Toft, Christina; Williams, Tom A.; Fares, Mario A.

    2009-01-01

    Symbiosis has been among the most important evolutionary steps to generate biological complexity. The establishment of symbiosis required an intimate metabolic link between biological systems with different complexity levels. The strict endo-cellular symbiotic bacteria of insects are beautiful examples of the metabolic coupling between organisms belonging to different kingdoms, a eukaryote and a prokaryote. The host (eukaryote) provides the endosymbiont (prokaryote) with a stable cellular environment while the endosymbiont supplements the host's diet with essential metabolites. For such communication to take place, endosymbionts' genomes have suffered dramatic modifications and reconfigurations of proteins' functions. Two of the main modifications, loss of genes redundant for endosymbiotic bacteria or the host and bacterial genome streamlining, have been extensively studied. However, no studies have accounted for possible functional shifts in the endosymbiotic proteomes. Here, we develop a simple method to screen genomes for evidence of functional divergence between two species clusters, and we apply it to identify functional shifts in the endosymbiotic proteomes. Despite the strong effects of genetic drift in the endosymbiotic systems, we unexpectedly identified genes to be under stronger selective constraints in endosymbionts of aphids and ants than in their free-living bacterial relatives. These genes are directly involved in supplementing the host's diet with essential metabolites. A test of functional divergence supports a strong relationship between the endosymbiosis and the functional shifts of proteins involved in the metabolic communication with the insect host. The correlation between functional divergence in the endosymbiotic bacterium and the ecological requirements of the host uncovers their intimate biochemical and metabolic communication and provides insights on the role of symbiosis in generating species diversity. PMID:19343224

  9. The Role of Complement in Cnidarian-Dinoflagellate Symbiosis and Immune Challenge in the Sea Anemone Aiptasia pallida.

    PubMed

    Poole, Angela Z; Kitchen, Sheila A; Weis, Virginia M

    2016-01-01

    The complement system is an innate immune pathway that in vertebrates, is responsible for initial recognition and ultimately phagocytosis and destruction of microbes. Several complement molecules including C3, Factor B, and mannose binding lectin associated serine proteases (MASP) have been characterized in invertebrates and while most studies have focused on their conserved role in defense against pathogens, little is known about their role in managing beneficial microbes. The purpose of this study was to (1) characterize complement pathway genes in the symbiotic sea anemone Aiptasia pallida, (2) investigate the evolution of complement genes in invertebrates, and (3) examine the potential dual role of complement genes Factor B and MASP in the onset and maintenance of cnidarian-dinoflagellate symbiosis and immune challenge using qPCR based studies. The results demonstrate that A. pallida has multiple Factor B genes (Ap_Bf-1, Ap_Bf-2a, and Ap_Bf-2b) and one MASP gene (Ap_MASP). Phylogenetic analysis indicates that the evolutionary history of complement genes is complex, and there have been many gene duplications or gene loss events, even within members of the same phylum. Gene expression analyses revealed a potential role for complement in both onset and maintenance of cnidarian-dinoflagellate symbiosis and immune challenge. Specifically, Ap_Bf-1 and Ap_MASP are significantly upregulated in the light at the onset of symbiosis and in response to challenge with the pathogen Serratia marcescens suggesting that they play a role in the initial recognition of both beneficial and harmful microbes. Ap_Bf-2b in contrast, was generally downregulated during the onset and maintenance of symbiosis and in response to challenge with S. marcescens. Therefore, the exact role of Ap_Bf-2b in response to microbes remains unclear, but the results suggest that the presence of microbes leads to repressed expression. Together, these results indicate functional divergence between Ap_Bf-1

  10. The role of the immune system in the initiation and persistence of the Euprymna scolopes-Vibrio fischeri symbiosis

    PubMed Central

    McFall-Ngai, Margaret; Nyholm, Spencer V.; Castillo, Maria G.

    2014-01-01

    The squid-vibrio symbiosis is an experimental system being studied as a model of the chronic colonization of animal epithelia by bacterial partners. One principal question being asked with this model is: what is the role of the immune system in the dynamics of the onset and maintenance of the symbiotic state? This review focuses upon results of research to date, which have demonstrated that both cell-mediated and cell-free components of the innate immune system are involved in these processes. PMID:20036144

  11. The Role of Complement in Cnidarian-Dinoflagellate Symbiosis and Immune Challenge in the Sea Anemone Aiptasia pallida

    PubMed Central

    Poole, Angela Z.; Kitchen, Sheila A.; Weis, Virginia M.

    2016-01-01

    The complement system is an innate immune pathway that in vertebrates, is responsible for initial recognition and ultimately phagocytosis and destruction of microbes. Several complement molecules including C3, Factor B, and mannose binding lectin associated serine proteases (MASP) have been characterized in invertebrates and while most studies have focused on their conserved role in defense against pathogens, little is known about their role in managing beneficial microbes. The purpose of this study was to (1) characterize complement pathway genes in the symbiotic sea anemone Aiptasia pallida, (2) investigate the evolution of complement genes in invertebrates, and (3) examine the potential dual role of complement genes Factor B and MASP in the onset and maintenance of cnidarian-dinoflagellate symbiosis and immune challenge using qPCR based studies. The results demonstrate that A. pallida has multiple Factor B genes (Ap_Bf-1, Ap_Bf-2a, and Ap_Bf-2b) and one MASP gene (Ap_MASP). Phylogenetic analysis indicates that the evolutionary history of complement genes is complex, and there have been many gene duplications or gene loss events, even within members of the same phylum. Gene expression analyses revealed a potential role for complement in both onset and maintenance of cnidarian-dinoflagellate symbiosis and immune challenge. Specifically, Ap_Bf-1 and Ap_MASP are significantly upregulated in the light at the onset of symbiosis and in response to challenge with the pathogen Serratia marcescens suggesting that they play a role in the initial recognition of both beneficial and harmful microbes. Ap_Bf-2b in contrast, was generally downregulated during the onset and maintenance of symbiosis and in response to challenge with S. marcescens. Therefore, the exact role of Ap_Bf-2b in response to microbes remains unclear, but the results suggest that the presence of microbes leads to repressed expression. Together, these results indicate functional divergence between Ap_Bf-1

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

    PubMed

    Glyan'ko, A K

    2015-01-01

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

  13. 7 CFR 1260.125 - Industry information.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE BEEF PROMOTION AND RESEARCH Beef Promotion and Research Order Definitions § 1260.125 Industry information. Industry information means information and programs that will lead to the development of new markets, marketing strategies,...

  14. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2004-01-01

    Part of the 2003 industrial minerals review. Supply and demand data for industrial diamond are provided. Topics discussed are consumption, prices, imports and exports, government stockpiles, and the outlook for 2004.

  15. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2012-01-01

    Estimated 2011 world production of natural and synthetic industrial diamond was about 4.45 billion carats. During 2011, natural industrial diamonds were produced in more than 20 countries, and synthetic industrial diamond was produced in at least 13 countries. About 98 percent of the combined natural and synthetic global output was produced in China, Ireland, Japan, Russia, South Africa and the United States. China is the world's leading producer of synthetic industrial diamond followed by Russia and the United States.

  16. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2006-01-01

    In 2005, estimated world production of natural and synthetic industrial diamond was 630 million carats. Natural industrial diamond deposits were found in more than 35 countries. Synthetic industrial diamond is produced in at least 15 countries. More than 81% of the combined natural and synthetic global output was produced in Ireland, Japan, Russia, South Africa and the United States.

  17. Industrial diamond

    USGS Publications Warehouse

    Olson, D.W.

    2011-01-01

    Estimated world production of natural and synthetic industrial diamond was about 4.44 billion carats in 2010. Natural industrial diamond deposits have been found in more than 35 countries, and synthetic industrial diamond is produced in at least 15 countries.

  18. Industrial Microbiology.

    ERIC Educational Resources Information Center

    Demain, Arnold L.; Solomon, Nadine A.

    1981-01-01

    Presents an overview of the field of industrial microbiology, providing historical backgrounds of scientific discoveries in the field and descriptions of industrially important microorganisms. Applied research in industry is also detailed, with mention of gene amplification, DNA recombination, pharmaceutical approaches, and detoxification and…

  19. Industry Employment

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2010

    2010-01-01

    This article illustrates projected employment change from an industry perspective over the 2008-2018 decade. Workers are grouped into an industry according to the type of good produced or service provided by the establishment in which they work. Industry employment projections are shown in terms of numeric change (growth or decline in the total…

  20. New Fungus-Insect Symbiosis: Culturing, Molecular, and Histological Methods Determine Saprophytic Polyporales Mutualists of Ambrosiodmus Ambrosia Beetles.

    PubMed

    Li, You; You, Li; Simmons, David Rabern; Bateman, Craig C; Short, Dylan P G; Kasson, Matthew T; Rabaglia, Robert J; Hulcr, Jiri

    2015-01-01

    Ambrosia symbiosis is an obligate, farming-like mutualism between wood-boring beetles and fungi. It evolved at least 11 times and includes many notorious invasive pests. All ambrosia beetles studied to date cultivate ascomycotan fungi: early colonizers of recently killed trees with poor wood digestion. Beetles in the widespread genus Ambrosiodmus, however, colonize decayed wood. We characterized the mycosymbionts of three Ambrosiodmus species using quantitative culturing, high-throughput metabarcoding, and histology. We determined the fungi to be within the Polyporales, closely related to Flavodon flavus. Culture-independent sequencing of Ambrosiodmus minor mycangia revealed a single operational taxonomic unit identical to the sequences from the cultured Flavodon. Histological sectioning confirmed that Ambrosiodmus possessed preoral mycangia containing dimitic hyphae similar to cultured F. cf. flavus. The Ambrosiodmus-Flavodon symbiosis is unique in several aspects: it is the first reported association between an ambrosia beetle and a basidiomycotan fungus; the mycosymbiont grows as hyphae in the mycangia, not as budding pseudo-mycelium; and the mycosymbiont is a white-rot saprophyte rather than an early colonizer: a previously undocumented wood borer niche. Few fungi are capable of turning rotten wood into complete animal nutrition. Several thousand beetle-fungus symbioses remain unstudied and promise unknown and unexpected mycological diversity and enzymatic innovations. PMID:26367271