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Sample records for modified crops resistant

  1. Biotechnology: herbicide-resistant crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic, herbicide-resistant (HR) crops are planted on about 80% of the land covered by transgenic crops. More than 90% of HR crios are glyphosate-resistant (GR) crops, the others being resistant to glufosinate. The wide-scale adoption of HR crops, largely for economic reasons, has been the mos...

  2. Promise and issues of genetically modified crops.

    PubMed

    Chen, Hao; Lin, Yongjun

    2013-05-01

    The growing area of genetically modified (GM) crops has substantially expanded since they were first commercialized in 1996. Correspondingly, the adoption of GM crops has brought huge economic and environmental benefits. All these achievements have been primarily supported by two simple traits of herbicide tolerance and insect resistance in the past 17 years. However, this situation will change soon. Recently, the advance of new products, technologies and safety assessment approaches has provided new opportunities for development of GM crops. In this review, we focus on the developmental trend in various aspects of GM crops including new products, technical innovation and risk assessment approaches, as well as potential challenges that GM crops are currently encountering. PMID:23571013

  3. Herbicide-resistant crops and weed resistance to herbicides.

    PubMed

    Owen, Micheal D K; Zelaya, Ian A

    2005-03-01

    The adoption of genetically modified (GM) crops has increased dramatically during the last 3 years, and currently over 52 million hectares of GM crops are planted world-wide. Approximately 41 million hectares of GM crops planted are herbicide-resistant crops, which includes an estimated 33.3 million hectares of herbicide-resistant soybean. Herbicide-resistant maize, canola, cotton and soybean accounted for 77% of the GM crop hectares in 2001. However, sugarbeet, wheat, and as many as 14 other crops have transgenic herbicide-resistant cultivars that may be commercially available in the near future. There are many risks associated with the production of GM and herbicide-resistant crops, including problems with grain contamination, segregation and introgression of herbicide-resistant traits, marketplace acceptance and an increased reliance on herbicides for weed control. The latter issue is represented in the occurrence of weed population shifts, the evolution of herbicide-resistant weed populations and herbicide-resistant crops becoming volunteer weeds. Another issue is the ecological impact that simple weed management programs based on herbicide-resistant crops have on weed communities. Asiatic dayflower (Commelina cumminus L) common lambsquarters (Chenopodium album L) and wild buckwheat (Polygonum convolvulus L) are reported to be increasing in prominence in some agroecosystems due to the simple and significant selection pressure brought to bear by herbicide-resistant crops and the concomitant use of the herbicide. Finally, evolution of herbicide-resistant weed populations attributable to the herbicide-resistant crop/herbicide program has been observed. Examples of herbicide-resistant weeds include populations of horseweed (Conyza canadensis (L) Cronq) resistant to N-(phosphonomethyl)glycine (glyphosate). An important question is whether or not these problems represent significant economic issues for future agriculture. PMID:15668920

  4. Metabolomics of Genetically Modified Crops

    PubMed Central

    Simó, Carolina; Ibáñez, Clara; Valdés, Alberto; Cifuentes, Alejandro; García-Cañas, Virginia

    2014-01-01

    Metabolomic-based approaches are increasingly applied to analyse genetically modified organisms (GMOs) making it possible to obtain broader and deeper information on the composition of GMOs compared to that obtained from traditional analytical approaches. The combination in metabolomics of advanced analytical methods and bioinformatics tools provides wide chemical compositional data that contributes to corroborate (or not) the substantial equivalence and occurrence of unintended changes resulting from genetic transformation. This review provides insight into recent progress in metabolomics studies on transgenic crops focusing mainly in papers published in the last decade. PMID:25334064

  5. Metabolomics of genetically modified crops.

    PubMed

    Simó, Carolina; Ibáñez, Clara; Valdés, Alberto; Cifuentes, Alejandro; García-Cañas, Virginia

    2014-01-01

    Metabolomic-based approaches are increasingly applied to analyse genetically modified organisms (GMOs) making it possible to obtain broader and deeper information on the composition of GMOs compared to that obtained from traditional analytical approaches. The combination in metabolomics of advanced analytical methods and bioinformatics tools provides wide chemical compositional data that contributes to corroborate (or not) the substantial equivalence and occurrence of unintended changes resulting from genetic transformation. This review provides insight into recent progress in metabolomics studies on transgenic crops focusing mainly in papers published in the last decade. PMID:25334064

  6. Genetically modified crops and food security.

    PubMed

    Qaim, Matin; Kouser, Shahzad

    2013-01-01

    The role of genetically modified (GM) crops for food security is the subject of public controversy. GM crops could contribute to food production increases and higher food availability. There may also be impacts on food quality and nutrient composition. Finally, growing GM crops may influence farmers' income and thus their economic access to food. Smallholder farmers make up a large proportion of the undernourished people worldwide. Our study focuses on this latter aspect and provides the first ex post analysis of food security impacts of GM crops at the micro level. We use comprehensive panel data collected over several years from farm households in India, where insect-resistant GM cotton has been widely adopted. Controlling for other factors, the adoption of GM cotton has significantly improved calorie consumption and dietary quality, resulting from increased family incomes. This technology has reduced food insecurity by 15-20% among cotton-producing households. GM crops alone will not solve the hunger problem, but they can be an important component in a broader food security strategy. PMID:23755155

  7. Transgenic Crops for Herbicide Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since their introduction in 1995, crops made resistant to the broad-spectrum herbicides glyphosate and glufosinate with transgenes are widely available and used in much of the world. As of 2008, over 80% of the transgenic crops grown world-wide have this transgenic trait. This technology has had m...

  8. Elevating crop disease resistance with cloned genes

    PubMed Central

    Jones, Jonathan D. G.; Witek, Kamil; Verweij, Walter; Jupe, Florian; Cooke, David; Dorling, Stephen; Tomlinson, Laurence; Smoker, Matthew; Perkins, Sara; Foster, Simon

    2014-01-01

    Essentially all plant species exhibit heritable genetic variation for resistance to a variety of plant diseases caused by fungi, bacteria, oomycetes or viruses. Disease losses in crop monocultures are already significant, and would be greater but for applications of disease-controlling agrichemicals. For sustainable intensification of crop production, we argue that disease control should as far as possible be achieved using genetics rather than using costly recurrent chemical sprays. The latter imply CO2 emissions from diesel fuel and potential soil compaction from tractor journeys. Great progress has been made in the past 25 years in our understanding of the molecular basis of plant disease resistance mechanisms, and of how pathogens circumvent them. These insights can inform more sophisticated approaches to elevating disease resistance in crops that help us tip the evolutionary balance in favour of the crop and away from the pathogen. We illustrate this theme with an account of a genetically modified (GM) blight-resistant potato trial in Norwich, using the Rpi-vnt1.1 gene isolated from a wild relative of potato, Solanum venturii, and introduced by GM methods into the potato variety Desiree. PMID:24535396

  9. Elevating crop disease resistance with cloned genes.

    PubMed

    Jones, Jonathan D G; Witek, Kamil; Verweij, Walter; Jupe, Florian; Cooke, David; Dorling, Stephen; Tomlinson, Laurence; Smoker, Matthew; Perkins, Sara; Foster, Simon

    2014-04-01

    Essentially all plant species exhibit heritable genetic variation for resistance to a variety of plant diseases caused by fungi, bacteria, oomycetes or viruses. Disease losses in crop monocultures are already significant, and would be greater but for applications of disease-controlling agrichemicals. For sustainable intensification of crop production, we argue that disease control should as far as possible be achieved using genetics rather than using costly recurrent chemical sprays. The latter imply CO₂ emissions from diesel fuel and potential soil compaction from tractor journeys. Great progress has been made in the past 25 years in our understanding of the molecular basis of plant disease resistance mechanisms, and of how pathogens circumvent them. These insights can inform more sophisticated approaches to elevating disease resistance in crops that help us tip the evolutionary balance in favour of the crop and away from the pathogen. We illustrate this theme with an account of a genetically modified (GM) blight-resistant potato trial in Norwich, using the Rpi-vnt1.1 gene isolated from a wild relative of potato, Solanum venturii, and introduced by GM methods into the potato variety Desiree. PMID:24535396

  10. Economic impacts of glyphosate-resistant crops.

    PubMed

    Gianessi, Leonard P

    2008-04-01

    Glyphosate-resistant crops have been widely planted since their introduction in 1996. Growers have numerous choices for herbicide treatments and have chosen to plant glyphosate-resistant crops on the basis of economic factors. The economic effects of the widespread planting of glyphosate-resistant crops have included reductions in herbicide expenses, increases in seed costs, increased yield and changes in the relative profitability of crops that has resulted in changes in which crops are planted. In addition, non-pecuniary benefits have accrued as a result of the simplicity of weed management in the glyphosate-resistant crop systems. PMID:18181242

  11. Gene flow from glyphosate-resistant crops.

    PubMed

    Mallory-Smith, Carol; Zapiola, Maria

    2008-04-01

    Gene flow from transgenic glyphosate-resistant crops can result in the adventitious presence of the transgene, which may negatively impact markets. Gene flow can also produce glyphosate-resistant plants that may interfere with weed management systems. The objective of this article is to review the gene flow literature as it pertains to glyphosate-resistant crops. Gene flow is a natural phenomenon not unique to transgenic crops and can occur via pollen, seed and, in some cases, vegetative propagules. Gene flow via pollen can occur in all crops, even those that are considered to be self-pollinated, because all have low levels of outcrossing. Gene flow via seed or vegetative propagules occurs when they are moved naturally or by humans during crop production and commercialization. There are many factors that influence gene flow; therefore, it is difficult to prevent or predict. Gene flow via pollen and seed from glyphosate-resistant canola and creeping bentgrass fields has been documented. The adventitious presence of the transgene responsible for glyphosate resistance has been found in commercial seed lots of canola, corn and soybeans. In general, the glyphosate-resistant trait is not considered to provide an ecological advantage. However, regulators should consider the examples of gene flow from glyphosate-resistant crops when formulating rules for the release of crops with traits that could negatively impact the environment or human health. PMID:18181145

  12. Potential for Entomopathogens to Delay Resistance to Bt Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The past decade has witnessed a continual increase in the use of crops genetically modified to produce insecticidal toxins from the bacterium Bacillus thuringiensis (Bt). This presents the challenge of designing agricultural systems to manage pests and the evolution of resistance to Bt. Currently,...

  13. Herbicide-resistant crops, resistant weeds, and herbicide drift

    Technology Transfer Automated Retrieval System (TEKTRAN)

    New herbicide-resistance traits in corn and soybean may bring new management challenges for fruit and vegetable growers in the Mid-Atlantic region. Herbicide-resistant crops are an important weed management technology in row crop agriculture that allow growers to apply an herbicide to control weed...

  14. Genetically modified crops: Brazilian law and overview.

    PubMed

    Marinho, C D; Martins, F J O; Amaral Júnior, A T; Gonçalves, L S A; dos Santos, O J A P; Alves, D P; Brasileiro, B P; Peternelli, L A

    2014-01-01

    In Brazil, the first genetically modified (GM) crop was released in 1998, and it is estimated that 84, 78, and 50% of crop areas containing soybean, corn, and cotton, respectively, were transgenic in 2012. This intense and rapid adoption rate confirms that the choice to use technology has been the main factor in developing national agriculture. Thus, this review focuses on understanding these dynamics in the context of farmers, trade relations, and legislation. To accomplish this goal, a survey was conducted using the database of the National Cultivar Registry and the National Service for Plant Variety Protection of the Ministry of Agriculture, Livestock and Supply [Ministério da Agricultura, Pecuária e Abastecimento (MAPA)] between 1998 and October 13, 2013. To date, 36 events have been released: five for soybeans, 18 for corn, 12 for cotton, and one for beans. From these events, 1395 cultivars have been developed and registered: 582 for soybean, 783 for corn and 30 for cotton. Monsanto owns 73.05% of the technologies used to develop these cultivars, while the Dow AgroScience - DuPont partnership and Syngenta have 16.34 and 4.37% ownership, respectively. Thus, the provision of transgenic seeds by these companies is an oligopoly supported by legislation. Moreover, there has been a rapid replacement of conventional crops by GM crops, whose technologies belong almost exclusively to four multinational companies, with the major ownership by Monsanto. These results reflect a warning to the government of the increased dependence on multinational corporations for key agricultural commodities. PMID:25061747

  15. The occurrence of antibiotic resistance genes in Taq polymerases and a decontamination method applied to the detection of genetically modified crops.

    PubMed

    Perron, André; Raymond, Philippe; Simard, Robin

    2006-03-01

    Different antibiotic resistance (AR) genes, such as Bla, Tet and NPTII, contaminate commercially available Taq polymerases. The specificity of the AR gene PCR can be increased when using a restriction enzyme-based decontamination of polymerase. The elimination of Taq polymerase contamination allows the use of PCR tests to screen seeds (corn) and processed food for the presence of genetically modified organisms (GMO) based on the detection of AR genes. Without a decontamination procedure for AR genes, PCR screening tests should be interpreted with caution. PMID:16614919

  16. Health Considerations Regarding Horizontal Transfer of Microbial Transgenes Present in Genetically Modified Crops

    PubMed Central

    Kleter, Gijs A.

    2005-01-01

    The potential effects of horizontal gene transfer on human health are an important item in the safety assessment of genetically modified organisms. Horizontal gene transfer from genetically modified crops to gut microflora most likely occurs with transgenes of microbial origin. The characteristics of microbial transgenes other than antibiotic-resistance genes in market-approved genetically modified crops are reviewed. These characteristics include the microbial source, natural function, function in genetically modified crops, natural prevalence, geographical distribution, similarity to other microbial genes, known horizontal transfer activity, selective conditions and environments for horizontally transferred genes, and potential contribution to pathogenicity and virulence in humans and animals. The assessment of this set of data for each of the microbial genes reviewed does not give rise to health concerns. We recommend including the above-mentioned items into the premarket safety assessment of genetically modified crops carrying transgenes other than those reviewed in the present study. PMID:16489267

  17. Herbicide-resistant crop biotechnology: potential and pitfalls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbicide-resistant crops are an important agricultural biotechnology that can enable farmers to effectively control weeds without harming their crops. Glyphosate-resistant (i.e. Roundup Ready) crops have been the most commercially successful varieties of herbicide-resistant crops and have been plan...

  18. Herbicide-Resistant Crops: Utilities and Limitations for Herbicide-Resistant Weed Management

    PubMed Central

    2010-01-01

    Since 1996, genetically modified herbicide-resistant (HR) crops, particularly glyphosate-resistant (GR) crops, have transformed the tactics that corn, soybean, and cotton growers use to manage weeds. The use of GR crops continues to grow, but weeds are adapting to the common practice of using only glyphosate to control weeds. Growers using only a single mode of action to manage weeds need to change to a more diverse array of herbicidal, mechanical, and cultural practices to maintain the effectiveness of glyphosate. Unfortunately, the introduction of GR crops and the high initial efficacy of glyphosate often lead to a decline in the use of other herbicide options and less investment by industry to discover new herbicide active ingredients. With some exceptions, most growers can still manage their weed problems with currently available selective and HR crop-enabled herbicides. However, current crop management systems are in jeopardy given the pace at which weed populations are evolving glyphosate resistance. New HR crop technologies will expand the utility of currently available herbicides and enable new interim solutions for growers to manage HR weeds, but will not replace the long-term need to diversify weed management tactics and discover herbicides with new modes of action. This paper reviews the strengths and weaknesses of anticipated weed management options and the best management practices that growers need to implement in HR crops to maximize the long-term benefits of current technologies and reduce weed shifts to difficult-to-control and HR weeds. PMID:20586458

  19. The state of genetically modified crop regulation in Canada.

    PubMed

    Smyth, Stuart J

    2014-07-01

    Genetically modified (GM) crops were first commercialized in Canada in 1995 and the 2014 crop represents the 20th year of successful production. Prior to the first commercialization of GM crops, Canada reviewed its existing science-based regulatory framework and adapted the existing framework to allow for risk assessments on the new technology to be undertaken in a timely and efficient manner. The result has been the rapid and widespread adoption of GM varieties of canola, corn and soybeans. The first decade of GM crop production precipitated 2 landmark legal cases relating to patent infringement and economic liability, while the second decade witnessed increased political efforts to have GM crops labeled in Canada as well as significant challenges from the low level comingling of GM crops with non-GM commodities. This article reviews the 20 y of GM crop production in Canada from a social science perspective that includes intellectual property, consumer acceptance and low level presence. PMID:25437238

  20. Genetically Modified Herbicide-Tolerant Crops, Weeds, and Herbicides: Overview and Impact.

    PubMed

    Bonny, Sylvie

    2016-01-01

    Genetically modified (GM) crops have been and continue to be a subject of controversy despite their rapid adoption by farmers where approved. For the last two decades, an important matter of debate has been their impact on pesticide use, particularly for herbicide-tolerant (HT) crops. Some claim that these crops bring about a decrease in herbicide use, while others claim the opposite. In fact, since 1996, most cultivated GMOs have been GMHT crops, which involve the use of an associated herbicide, generally glyphosate. In their very first years of adoption, HT crops often led to some decrease in herbicide use. However, the repetition of glyphosate-tolerant crops and of glyphosate only applications in the same fields without sufficient alternation and herbicide diversity has contributed to the appearance of glyphosate-resistant weeds. These weeds have resulted in a rise in the use of glyphosate and other herbicides. This article explores this situation and the impacts of herbicide-resistant weeds, using an interdisciplinary approach and drawing on recent data. The paper analyzes the spread of GMHT crops worldwide and their consequences on herbicide use in the USA in particular. It then addresses the global development of glyphosate-resistant weeds and their impact, particularly focusing on the USA. Finally, the last section explores how industry, farmers, and weed scientists are coping with the spread of resistant weeds. The concluding comments deal more widely with trends in GM crops. PMID:26296738

  1. Genetically Modified Herbicide-Tolerant Crops, Weeds, and Herbicides: Overview and Impact

    NASA Astrophysics Data System (ADS)

    Bonny, Sylvie

    2016-01-01

    Genetically modified (GM) crops have been and continue to be a subject of controversy despite their rapid adoption by farmers where approved. For the last two decades, an important matter of debate has been their impact on pesticide use, particularly for herbicide-tolerant (HT) crops. Some claim that these crops bring about a decrease in herbicide use, while others claim the opposite. In fact, since 1996, most cultivated GMOs have been GMHT crops, which involve the use of an associated herbicide, generally glyphosate. In their very first years of adoption, HT crops often led to some decrease in herbicide use. However, the repetition of glyphosate-tolerant crops and of glyphosate only applications in the same fields without sufficient alternation and herbicide diversity has contributed to the appearance of glyphosate-resistant weeds. These weeds have resulted in a rise in the use of glyphosate and other herbicides. This article explores this situation and the impacts of herbicide-resistant weeds, using an interdisciplinary approach and drawing on recent data. The paper analyzes the spread of GMHT crops worldwide and their consequences on herbicide use in the USA in particular. It then addresses the global development of glyphosate-resistant weeds and their impact, particularly focusing on the USA. Finally, the last section explores how industry, farmers, and weed scientists are coping with the spread of resistant weeds. The concluding comments deal more widely with trends in GM crops.

  2. Weed resistance challenges and management under herbicide resistant cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over the last six decades, herbicides have been the mainstay of weed management in cropping systems around the world, especially in the Western Hemisphere. A direct consequence of intensive use of herbicides is the development of resistance in weed populations. The extreme popularity of transgenic g...

  3. Proteomic evaluation of genetically modified crops: current status and challenges.

    PubMed

    Gong, Chun Yan; Wang, Tai

    2013-01-01

    Hectares of genetically modified (GM) crops have increased exponentially since 1996, when such crops began to be commercialized. GM biotechnology, together with conventional breeding, has become the main approach to improving agronomic traits of crops. However, people are concerned about the safety of GM crops, especially GM-derived food and feed. Many efforts have been made to evaluate the unintended effects caused by the introduction of exogenous genes. "Omics" techniques have advantages over targeted analysis in evaluating such crops because of their use of high-throughput screening. Proteins are key players in gene function and are directly involved in metabolism and cellular development or have roles as toxins, antinutrients, or allergens, which are essential for human health. Thus, proteomics can be expected to become one of the most useful tools in safety assessment. This review assesses the potential of proteomics in evaluating various GM crops. We further describe the challenges in ensuring homogeneity and sensitivity in detection techniques. PMID:23471542

  4. [Assessment of allergenicity of genetically modified food crops].

    PubMed

    Schauzu, M; Pöting, A; Rubin, D; Lampen, A

    2012-03-01

    The placing on the European Union's market of genetically modified crops requires authorization by the European Commission which is based on the proof that the derived foods are as safe as their conventional counterparts. The assessment of potential allergenicity is part of the necessary investigations recommended in the updated Guidance Document of the Scientific Panel on Genetically Modified Organisms (GMO) of the European Food Safety Authority (EFSA), which is based on internationally agreed recommendations. All genetically modified crops which so far have been authorized in the European Union were evaluated by the EFSA GMO Panel which considered it unlikely that their overall allergenicity has been altered. PMID:22373855

  5. Effects of Transgenic Glyphosate-Resistant Crops on Water Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate (N-[phosphonomethyl] glycine) is a highly effective, non-selective herbicide. Herbicide-resistant crop (HRC) has been the most successful trait used in transgenic crops throughout the world. Transgenic glyphosate-resistant crops (GRCs) have been commercialized and grown extensively in the...

  6. Is genetically modified crop the answer for the next green revolution?

    PubMed

    Basu, Saikat Kumar; Dutta, Madhuleema; Goyal, Aakash; Bhowmik, Pankaj Kumar; Kumar, Jitendra; Nandy, Sanjib; Scagliusi, Sandra Mansun; Prasad, Rajib

    2010-01-01

    Post-green revolution advances made in biotechnology paved the way of cultivating the high-yielding, stress and disease resistant genetically modified (GM) varieties of wheat, rice, maize cotton and several other crops. The recent rapid commercialization of the genetically modified crops in Asia, Americas and Australia indicates the potentiality of this new technology. GM crops give higher yields and are rich in nutritional values containing vitamins and minerals and can thus can help to alleviate hunger and malnutrition of the growing population in the under developed and developing countries. It could also be possible to develop more biotic and abiotic stress resistant genotypes in these crops where it was difficult to develop due to the unavailability of genes of resistance in the crossing germplasms. However, further research and investigations are needed to popularize the cultivation of these crops in different parts of the world. This review provides an insight of the impact of GM crops on contemporary agriculture across the past few decades, traces its' history across time, highlights new achievements and breakthroughs and discusses the future implication of this powerful technology in the coming few decades. PMID:21865874

  7. Biosafety management and commercial use of genetically modified crops in China.

    PubMed

    Li, Yunhe; Peng, Yufa; Hallerman, Eric M; Wu, Kongming

    2014-04-01

    As a developing country with relatively limited arable land, China is making great efforts for development and use of genetically modified (GM) crops to boost agricultural productivity. Many GM crop varieties have been developed in China in recent years; in particular, China is playing a leading role in development of insect-resistant GM rice lines. To ensure the safe use of GM crops, biosafety risk assessments are required as an important part of the regulatory oversight of such products. With over 20 years of nationwide promotion of agricultural biotechnology, a relatively well-developed regulatory system for risk assessment and management of GM plants has been developed that establishes a firm basis for safe use of GM crops. So far, a total of seven GM crops involving ten events have been approved for commercial planting, and 5 GM crops with a total of 37 events have been approved for import as processing material in China. However, currently only insect-resistant Bt cotton and disease-resistant papaya have been commercially planted on a large scale. The planting of Bt cotton and disease-resistant papaya have provided efficient protection against cotton bollworms and Papaya ringspot virus (PRSV), respectively. As a consequence, chemical application to these crops has been significantly reduced, enhancing farm income while reducing human and non-target organism exposure to toxic chemicals. This article provides useful information for the colleagues, in particular for them whose mother tongue is not Chinese, to clearly understand the biosafety regulation and commercial use of genetically modified crops in China. PMID:24493253

  8. Genetically modified crops: detection strategies and biosafety issues.

    PubMed

    Kamle, Suchitra; Ali, Sher

    2013-06-15

    Genetically modified (GM) crops are increasingly gaining acceptance but concurrently consumers' concerns are also increasing. The introduction of Bacillus thuringiensis (Bt) genes into the plants has raised issues related to its risk assessment and biosafety. The International Regulations and the Codex guidelines regulate the biosafety requirements of the GM crops. In addition, these bodies synergize and harmonize the ethical issues related to the release and use of GM products. The labeling of GM crops and their products are mandatory if the genetically modified organism (GMO) content exceeds the levels of a recommended threshold. The new and upcoming GM crops carrying multiple stacked traits likely to be commercialized soon warrant sensitive detection methods both at the DNA and protein levels. Therefore, traceability of the transgene and its protein expression in GM crops is an important issue that needs to be addressed on a priority basis. The advancement in the area of molecular biology has made available several bioanalytical options for the detection of GM crops based on DNA and protein markers. Since the insertion of a gene into the host genome may even cause copy number variation, this may be uncovered using real time PCR. Besides, assessing the exact number of mRNA transcripts of a gene, correlation between the template activity and expressed protein may be established. Here, we present an overview on the production of GM crops, their acceptabilities, detection strategies, biosafety issues and potential impact on society. Further, overall future prospects are also highlighted. PMID:23566850

  9. Environmental Impacts of Transgenic Herbicide-Resistant Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic glufosinate- and glyphosate-resistant crops are currently commercialized, and bromoxynil-resistant crops have been removed from the market for economic reasons. Glyphosate-resistant cotton and soybean have become dominant in those countries where they can be grown. Potential effects of gl...

  10. Transgenic Herbicide-resistant Crops and Environmental Impacts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic glufosinate- and glyphosate-resistant crops are currently commercialized, and bromoxynil-resistant crops have been removed from the market for economic reasons. Glyphosate-resistant cotton and soybean have become dominant in those countries where they can be grown. Potential effects of gl...

  11. Genetically modified crops and small-scale farmers: main opportunities and challenges.

    PubMed

    Azadi, Hossein; Samiee, Atry; Mahmoudi, Hossein; Jouzi, Zeynab; Khachak, Parisa Rafiaani; De Maeyer, Philippe; Witlox, Frank

    2016-01-01

    Although some important features of genetically modified (GM) crops such as insect resistance, herbicide tolerance, and drought tolerance might seem to be beneficial for small-scale farmers, the adoption of GM technology by smallholders is still slight. Identifying pros and cons of using this technology is important to understand the impacts of GM crops on these farmers. This article reviews the main opportunities and challenges of GM crops for small-scale farmers in developing countries. The most significant advantages of GM crops include being independent to farm size, environment protection, improvement of occupational health issues, and the potential of bio-fortified crops to reduce malnutrition. Challenges faced by small-scale farmers for adoption of GM crops comprise availability and accessibility of GM crop seeds, seed dissemination and price, and the lack of adequate information. In addition, R&D and production costs in using GM crops make it difficult for these farmers to adopt the use of these crops. Moreover, intellectual property right regulations may deprive resource poor farmers from the advantages of GM technology. Finally, concerns on socio-economic and environment safety issues are also addressed in this paper. PMID:25566797

  12. Proteomic evaluation of genetically modified crops: current status and challenges

    PubMed Central

    Gong, Chun Yan; Wang, Tai

    2013-01-01

    Hectares of genetically modified (GM) crops have increased exponentially since 1996, when such crops began to be commercialized. GM biotechnology, together with conventional breeding, has become the main approach to improving agronomic traits of crops. However, people are concerned about the safety of GM crops, especially GM-derived food and feed. Many efforts have been made to evaluate the unintended effects caused by the introduction of exogenous genes. “Omics” techniques have advantages over targeted analysis in evaluating such crops because of their use of high-throughput screening. Proteins are key players in gene function and are directly involved in metabolism and cellular development or have roles as toxins, antinutrients, or allergens, which are essential for human health. Thus, proteomics can be expected to become one of the most useful tools in safety assessment. This review assesses the potential of proteomics in evaluating various GM crops. We further describe the challenges in ensuring homogeneity and sensitivity in detection techniques. PMID:23471542

  13. Regulatory options for genetically modified crops in India.

    PubMed

    Choudhary, Bhagirath; Gheysen, Godelieve; Buysse, Jeroen; van der Meer, Piet; Burssens, Sylvia

    2014-02-01

    The introduction of semi-dwarfing, high-yielding and nutrients-responsive crop varieties in the 1960s and 1970s alleviated the suffering of low crop yield, food shortages and epidemics of famine in India and other parts of the Asian continent. Two semi-dwarfing genes, Rht in wheat and Sd-1 in rice heralded the green revolution for which Dr. Norman Borlaug was awarded the Nobel Peace Prize in 1970. In contrast, the revolutionary new genetics of crop improvement shamble over formidable obstacles of regulatory delays, political interferences and public misconceptions. India benefited immensely from the green revolution and is now grappling to deal with the nuances of GM crops. The development of GM mustard discontinued prematurely in 2001 and insect-resistant Bt cotton varieties were successfully approved for commercial cultivation in 2002 in an evolving nature of regulatory system. However, the moratorium on Bt brinjal by MOEF in 2010 meant a considerable detour from an objective, science-based, rigorous institutional process of regulatory approval to a more subjective, nonscience-driven, political decision-making process. This study examines what ails the regulatory system of GM crops in India and the steps that led to the regulatory logjam. Responding to the growing challenges and impediments of existing biosafety regulation, it suggests options that are critical for GM crops to take roots for a multiplier harvest. PMID:24460889

  14. Synergistic interactions between entomopathogenic nematodes and Bt crops: integrating biological control and resistance management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased use of crops genetically modified to produce insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) presents the challenge of designing agricultural systems to manage pests and the evolution of resistance to Bt. We tested whether entomopathogenic nematodes might act synergisti...

  15. Assessment of Risk of Insect-resistant Transgenic Crops to Nontarget Arthropods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An international initiative is developing a scientifically rigorous approach to evaluate potential risks to non-target arthropods (NTA’s) posed by insect-resistant, genetically modified (IRGM) crops. It adapts the tiered approach to risk assessment that is accepted internationally within regulatory ...

  16. Herbicide-Resistant: Toward an understanding of resistance development and the impact of herbicide resistant crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For the past half century, herbicides have been the principal means of economic weed management in commercial crops in the US. Although weed resistance to herbicides was anticipated, weeds with resistance to herbicides did not appear until over 20 years after the initiation of herbicide use. Weed co...

  17. Recent Advances on the Molecular Basis of Crop Aluminum Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The considerable genetic variability for aluminum (Al) resistance within many crop plant species has been utilized by plant breeders for a number of years to enhance Al resistance. But beyond this, genetic variability in Al resistance has been an excellent experimental resource that is being mined b...

  18. Suppressing resistance to Bt crops without refuges: fact or folly?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The predominant strategy for delaying insect resistance to transgenic insecticidal crops requires refuges of non-transgenic host plants to provide susceptible insects for mating with resistant insects. Here, an alternative strategy where sterile insects are released to mate with resistant insects i...

  19. Global Adoption of Genetically Modified (GM) Crops: Challenges for the Public Sector.

    PubMed

    Huesing, Joseph E; Andres, David; Braverman, Michael P; Burns, Andrea; Felsot, Allan S; Harrigan, George G; Hellmich, Richard L; Reynolds, Alan; Shelton, Anthony M; Jansen van Rijssen, Wilna; Morris, E Jane; Eloff, Jacobus N

    2016-01-20

    Advances in biotechnology continue to drive the development of a wide range of insect-protected, herbicide-tolerant, stress-tolerant, and nutritionally enhanced genetically modified (GM) crops, yet societal and public policy considerations may slow their commercialization. Such restrictions may disproportionately affect developing countries, as well as smaller entrepreneurial and public sector initiatives. The 2014 IUPAC International Congress of Pesticide Chemistry (San Francisco, CA, USA; August 2014) included a symposium on "Challenges Associated with Global Adoption of Agricultural Biotechnology" to review current obstacles in promoting GM crops. Challenges identified by symposium presenters included (i) poor public understanding of GM technology and the need for enhanced communication strategies, (ii) nonharmonized and prescriptive regulatory requirements, and (iii) limited experience with regulations and product development within some public sector programs. The need for holistic resistance management programs to enable the most effective use of insect-protected crops was also a point of emphasis. This paper provides details on the symposium discussion and provides background information that can be used in support of further adoption of beneficial GM crops. Overall, it emphasizes that global adoption of modern agricultural biotechnology has not only provided benefits to growers and consumers but has great potential to provide solutions to an increasing global population and diminishing agricultural land. This potential will be realized by continued scientific innovation, harmonized regulatory systems, and broader communication of the benefits of the high-yielding, disease-resistant, and nutritionally enhanced crops attainable through modern biotechnology. PMID:26751159

  20. Herbicide resistant crops: history, development, and current technologies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Advances in biotechnology have led to development and commercialization of several herbicide-resistant crops (HRCs) in the mid-1990s. HRCs survive herbicide treatment that previously would have killed the crop along with targeted weeds. Both transgenic (created through stable integration of a foreig...

  1. GLYPHOSATE AND GLYPHOSATE-RESISTANT CROP INTERACTIONS WITH RHIZOSPHERE MICROORGANISMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate and glyphosate-resistant crops represent a major advancement in effective weed management that is now widely used in many crop production systems. Studies conducted during 1997-2007 showed that Fusarium root colonization was consistently higher on Roundup Ready (RR) soybean treated with g...

  2. Risk assessment of genetically modified crops for nutrition and health.

    PubMed

    Magaña-Gómez, Javier A; de la Barca, Ana M Calderón

    2009-01-01

    The risk assessment of genetically modified (GM) crops for human nutrition and health has not been systematic. Evaluations for each GM crop or trait have been conducted using different feeding periods, animal models, and parameters. The most common result is that GM and conventional sources induce similar nutritional performance and growth in animals. However, adverse microscopic and molecular effects of some GM foods in different organs or tissues have been reported. Diversity among the methods and results of the risk assessments reflects the complexity of the subject. While there are currently no standardized methods to evaluate the safety of GM foods, attempts towards harmonization are on the way. More scientific effort is necessary in order to build confidence in the evaluation and acceptance of GM foods. PMID:19146501

  3. Food Allergy - Basic Mechanisms and Applications to Identifying Risks Associated with Plant Incorporated Pesticides and Other Genetically Modified Crops

    EPA Science Inventory

    Food allergy is a relatively new concern for toxicologists as a result of the incorporation of novel proteins into food crops in order to promote resistance to pests and other stresses, improve nutrition, or otherwise modify the phenotype. Food allergy can manifest as inflammatio...

  4. Genetically modified crops: success, safety assessment, and public concern.

    PubMed

    Singh, Om V; Ghai, Shivani; Paul, Debarati; Jain, Rakesh K

    2006-08-01

    With the emergence of transgenic technologies, new ways to improve the agronomic performance of crops for food, feed, and processing applications have been devised. In addition, ability to express foreign genes using transgenic technologies has opened up options for producing large quantities of commercially important industrial or pharmaceutical products in plants. Despite this high adoption rate and future promises, there is a multitude of concerns about the impact of genetically modified (GM) crops on the environment. Potential contamination of the environment and food chains has prompted detailed consideration of how such crops and the molecules that they produce can be effectively isolated and contained. One of the reasonable steps after creating a transgenic plant is to evaluate its potential benefits and risks to the environment and these should be compared to those generated by traditional agricultural practices. The precautionary approach in risk management of GM plants may make it necessary to monitor significant wild and weed populations that might be affected by transgene escape. Effective risk assessment and monitoring mechanisms are the basic prerequisites of any legal framework to adequately address the risks and watch out for new risks. Several agencies in different countries monitor the release of GM organisms or frame guidelines for the appropriate application of recombinant organisms in agro-industries so as to assure the safe use of recombinant organisms and to achieve sound overall development. We feel that it is important to establish an internationally harmonized framework for the safe handling of recombinant DNA organisms within a few years. PMID:16639559

  5. Natural Enemies Delay Insect Resistance to Bt Crops

    PubMed Central

    Liu, Xiaoxia; Chen, Mao; Collins, Hilda L.; Onstad, David W.; Roush, Richard T.; Zhang, Qingwen; Earle, Elizabeth D.; Shelton, Anthony M.

    2014-01-01

    We investigated whether development of resistance to a Bt crop in the presence of a natural enemy would be slower than without the natural enemy and whether biological control, in conjunction with a Bt crop, could effectively suppress the pest population. Additionally, we investigated whether insecticide-sprayed refuges of non-Bt crops would delay or accelerate resistance to the Bt crop. We used a system of Bt broccoli expressing Cry1Ac, a population of the pest Plutella xylostella with a low frequency of individuals resistant to Cry1Ac and the insecticide spinosad, and a natural enemy, Coleomegilla maculata, to conduct experiments over multiple generations. The results demonstrated that after 6 generations P. xylostella populations were very low in the treatment containing C. maculata and unsprayed non-Bt refuge plants. Furthermore, resistance to Bt plants evolved significantly slower in this treatment. In contrast, Bt plants with no refuge were completely defoliated in treatments without C. maculata after 4–5 generations. In the treatment containing sprayed non-Bt refuge plants and C. maculata, the P. xylostella population was low, although the speed of resistance selection to Cry1Ac was significantly increased. These data demonstrate that natural enemies can delay resistance to Bt plants and have significant implications for integrated pest management (IPM) with Bt crops. PMID:24595158

  6. Integrating insect-resistant GM Crops in pest management systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2006, GM cotton and maize with insect resistance were grown on 12.1 and 20.1 million hectares in 9 and 13 countries, respectively. These insect resistant GM crops produce various Cry toxins from Bacillus thuringiensis (Bt) and provide highly selective and effective control of lepidopteran and col...

  7. Resistance Management Research for PIP Crops

    EPA Science Inventory

    A significant increase in genetically modified corn planting driven by biofuel demand is expected for future planted acreages approaching 80% of total corn plantings in 2009. As demand increases, incidence of farmer non-compliance with mandated non-genetically modified refuge is...

  8. Characteristics and safety assessment of intractable proteins in genetically modified crops.

    PubMed

    Bushey, Dean F; Bannon, Gary A; Delaney, Bryan F; Graser, Gerson; Hefford, Mary; Jiang, Xiaoxu; Lee, Thomas C; Madduri, Krishna M; Pariza, Michael; Privalle, Laura S; Ranjan, Rakesh; Saab-Rincon, Gloria; Schafer, Barry W; Thelen, Jay J; Zhang, John X Q; Harper, Marc S

    2014-07-01

    Genetically modified (GM) crops may contain newly expressed proteins that are described as "intractable". Safety assessment of these proteins may require some adaptations to the current assessment procedures. Intractable proteins are defined here as those proteins with properties that make it extremely difficult or impossible with current methods to express in heterologous systems; isolate, purify, or concentrate; quantify (due to low levels); demonstrate biological activity; or prove equivalency with plant proteins. Five classes of intractable proteins are discussed here: (1) membrane proteins, (2) signaling proteins, (3) transcription factors, (4) N-glycosylated proteins, and (5) resistance proteins (R-proteins, plant pathogen recognition proteins that activate innate immune responses). While the basic tiered weight-of-evidence approach for assessing the safety of GM crops proposed by the International Life Sciences Institute (ILSI) in 2008 is applicable to intractable proteins, new or modified methods may be required. For example, the first two steps in Tier I (hazard identification) analysis, gathering of applicable history of safe use (HOSU) information and bioinformatics analysis, do not require protein isolation. The extremely low level of expression of most intractable proteins should be taken into account while assessing safety of the intractable protein in GM crops. If Tier II (hazard characterization) analyses requiring animal feeding are judged to be necessary, alternatives to feeding high doses of pure protein may be needed. These alternatives are discussed here. PMID:24662477

  9. Weed control changes and genetically modified herbicide tolerant crops in the USA 1996-2012.

    PubMed

    Brookes, Graham

    2014-01-01

    Crops that have been genetically modified (GM) to be tolerant to herbicides have been widely grown in the USA since 1996. The rapid and widespread adoption of this technology reflects the important economic and environmental benefits that farmers have derived from its use (equal to $21.7 billion additional farm income and a 225 million kg reduction in herbicide active ingredient use 1996-2012). During this time, weed control practices in these crops relative to the 'conventional alternative' have evolved to reflect experience of using the technology, the challenges that have arisen and the increasing focus in recent years on developing sustainable production systems. This paper examines the evidence on the changing nature of herbicides used with these crops and in particular how farmers addressed the challenge of weed resistance. The evidence shows that use of the technology has resulted in a net reduction in both the amount of herbicide used and the associated environmental impact, as measured by the EIQ indicator when compared to what can reasonably be expected if the area planted to GM HT crops reverted to conventional production methods. It also facilitated many farmers being able to derive the economic and environmental benefits associated with switching from a plough-based to a no tillage or conservation tillage production system. In terms of herbicide use, the technology has also contributed to a change the profile of herbicides used. A broad range of, mostly selective herbicides has been replaced by one or 2 broad-spectrum herbicides (mostly glyphosate) used in conjunction with one or 2 other (complementary) herbicides. Since the mid-2000s, the average amount of herbicide applied and the associated environmental load, as measured by the EIQ indicator, have increased on both GM HT and conventional crops. A primary reason for these changes has been increasing incidence of weed species developing populations resistant to herbicides and increased awareness of

  10. Current state of herbicides in herbicide-resistant crops.

    PubMed

    Green, Jerry M

    2014-09-01

    Current herbicide and herbicide trait practices are changing in response to the rapid spread of glyphosate-resistant weeds. Growers urgently needed glyphosate when glyphosate-resistant crops became available because weeds were becoming widely resistant to most commonly used selective herbicides, making weed management too complex and time consuming for large farm operations. Glyphosate made weed management easy and efficient by controlling all emerged weeds at a wide range of application timings. However, the intensive use of glyphosate over wide areas and concomitant decline in the use of other herbicides led eventually to the widespread evolution of weeds resistant to glyphosate. Today, weeds that are resistant to glyphosate and other herbicide types are threatening current crop production practices. Unfortunately, all commercial herbicide modes of action are over 20 years old and have resistant weed problems. The severity of the problem has prompted the renewal of efforts to discover new weed management technologies. One technology will be a new generation of crops with resistance to glyphosate, glufosinate and other existing herbicide modes of action. Other technologies will include new chemical, biological, cultural and mechanical methods for weed management. From the onset of commercialization, growers must now preserve the utility of new technologies by integrating their use with other weed management technologies in diverse and sustainable systems. PMID:24446395

  11. Weed species shifts in glyphosate-resistant crops.

    PubMed

    Owen, Micheal D K

    2008-04-01

    The adoption of glyphosate-based crop production systems has been one of the most important revolutions in the history of agriculture. Changes in weed communities owing to species that do not respond to current glyphosate-based management tactics are rapidly increasing. Clearly, glyphosate-resistant crops (GRCs) do not influence weeds any more than non-transgenic crops. For most crops, the trait itself is essentially benign in the environment. Rather, the weed control tactics imposed by growers create the ecological selection pressure that ultimately changes the weed communities. This is seen in the adoption of conservation tillage and weed management programs that focus on one herbicide mode of action and have hastened several important weed population shifts. Tillage (disturbance) is one of the primary factors that affect changes in weed communities. The intense selection pressure from herbicide use will result in the evolution of herbicide-resistant weed biotypes or shifts in the relative prominence of one weed species in the weed community. Changes in weed communities are inevitable and an intrinsic consequence of growing crops over time. The glyphosate-based weed management tactics used in GRCs impose the selection pressure that supports weed population shifts. Examples of weed population shifts in GRCs include common waterhemp [Amaranthus tuberculatus (Moq ex DC) JD Sauer], horseweed (Conyza canadensis L), giant ragweed (Ambrosia trifida L) and other relatively new weed problems. Growers have handled these weed population shifts with varying success depending on the crop. PMID:18232055

  12. The impact of altered herbicide residues in transgenic herbicide-resistant crops on standard setting for herbicide residues.

    PubMed

    Kleter, Gijs A; Unsworth, John B; Harris, Caroline A

    2011-10-01

    The global area covered with transgenic (genetically modified) crops has rapidly increased since their introduction in the mid-1990s. Most of these crops have been rendered herbicide resistant, for which it can be envisaged that the modification has an impact on the profile and level of herbicide residues within these crops. In this article, the four main categories of herbicide resistance, including resistance to acetolactate-synthase inhibitors, bromoxynil, glufosinate and glyphosate, are reviewed. The topics considered are the molecular mechanism underlying the herbicide resistance, the nature and levels of the residues formed and their impact on the residue definition and maximum residue limits (MRLs) defined by the Codex Alimentarius Commission and national authorities. No general conclusions can be drawn concerning the nature and level of residues, which has to be done on a case-by-case basis. International residue definitions and MRLs are still lacking for some herbicide-crop combinations, and harmonisation is therefore recommended. PMID:21898904

  13. Development of agribiotechnology and biosafety regulations used to assess safety of genetically modified crops in Bangladesh.

    PubMed

    Nasiruddin, Khondoker M; Nasim, Anwar

    2007-01-01

    Bangladesh is on the verge of adopting genetically modified (GM) crops for commercial cultivation and consumption as feed and food. Most of the laboratories are engaged in tissue culture and molecular characterization on plants, whereas some have started living modified organism research with shortages of trained manpower, infrastructure, and funding. Nutritionally improved Golden Rice, biotech brinjal, and late blight-resistant potato are in contained trials in a greenhouse, and potato ring spot virus-resistant papaya is in the process of approval for a field trial. The government has taken some initiative in support of GM organism research, which include the formation of a Biotechnology Department in all institutes and the formation of the apex body, the National Task Force Committee on Biotechnology of Bangladesh under the chairpersonship of the Prime Minister. Biosafety policy guidelines and related aspects of biotechnology issues have been approved, and the laws are in the process of being promulgated. Being a party to the Cartagena Protocol, proper biosafety measures are regulated by the appropriate authority as stated. Although there are no laws made yet directly for biosafety of GM crops/foods, the relevant laws on agriculture, medicine, food, import, trade, environment, etc. may suffice and explain the situation. PMID:17956000

  14. Robust crop resistance to broadleaf and grass herbicides provided by aryloxyalkanoate dioxygenase transgenes.

    PubMed

    Wright, Terry R; Shan, Guomin; Walsh, Terence A; Lira, Justin M; Cui, Cory; Song, Ping; Zhuang, Meibao; Arnold, Nicole L; Lin, Gaofeng; Yau, Kerrm; Russell, Sean M; Cicchillo, Robert M; Peterson, Mark A; Simpson, David M; Zhou, Ning; Ponsamuel, Jayakumar; Zhang, Zhanyuan

    2010-11-23

    Engineered glyphosate resistance is the most widely adopted genetically modified trait in agriculture, gaining widespread acceptance by providing a simple robust weed control system. However, extensive and sustained use of glyphosate as a sole weed control mechanism has led to field selection for glyphosate-resistant weeds and has induced significant population shifts to weeds with inherent tolerance to glyphosate. Additional weed control mechanisms that can complement glyphosate-resistant crops are, therefore, urgently needed. 2,4-dichlorophenoxyacetic acid (2,4-D) is an effective low-cost, broad-spectrum herbicide that controls many of the weeds developing resistance to glyphosate. We investigated the substrate preferences of bacterial aryloxyalkanoate dioxygenase enzymes (AADs) that can effectively degrade 2,4-D and have found that some members of this class can act on other widely used herbicides in addition to their activity on 2,4-D. AAD-1 cleaves the aryloxyphenoxypropionate family of grass-active herbicides, and AAD-12 acts on pyridyloxyacetate auxin herbicides such as triclopyr and fluroxypyr. Maize plants transformed with an AAD-1 gene showed robust crop resistance to aryloxyphenoxypropionate herbicides over four generations and were also not injured by 2,4-D applications at any growth stage. Arabidopsis plants expressing AAD-12 were resistant to 2,4-D as well as triclopyr and fluroxypyr, and transgenic soybean plants expressing AAD-12 maintained field resistance to 2,4-D over five generations. These results show that single AAD transgenes can provide simultaneous resistance to a broad repertoire of agronomically important classes of herbicides, including 2,4-D, with utility in both monocot and dicot crops. These transgenes can help preserve the productivity and environmental benefits of herbicide-resistant crops. PMID:21059954

  15. Robust crop resistance to broadleaf and grass herbicides provided by aryloxyalkanoate dioxygenase transgenes

    PubMed Central

    Wright, Terry R.; Shan, Guomin; Walsh, Terence A.; Lira, Justin M.; Cui, Cory; Song, Ping; Zhuang, Meibao; Arnold, Nicole L.; Lin, Gaofeng; Yau, Kerrm; Russell, Sean M.; Cicchillo, Robert M.; Peterson, Mark A.; Simpson, David M.; Zhou, Ning; Ponsamuel, Jayakumar; Zhang, Zhanyuan

    2010-01-01

    Engineered glyphosate resistance is the most widely adopted genetically modified trait in agriculture, gaining widespread acceptance by providing a simple robust weed control system. However, extensive and sustained use of glyphosate as a sole weed control mechanism has led to field selection for glyphosate-resistant weeds and has induced significant population shifts to weeds with inherent tolerance to glyphosate. Additional weed control mechanisms that can complement glyphosate-resistant crops are, therefore, urgently needed. 2,4-dichlorophenoxyacetic acid (2,4-D) is an effective low-cost, broad-spectrum herbicide that controls many of the weeds developing resistance to glyphosate. We investigated the substrate preferences of bacterial aryloxyalkanoate dioxygenase enzymes (AADs) that can effectively degrade 2,4-D and have found that some members of this class can act on other widely used herbicides in addition to their activity on 2,4-D. AAD-1 cleaves the aryloxyphenoxypropionate family of grass-active herbicides, and AAD-12 acts on pyridyloxyacetate auxin herbicides such as triclopyr and fluroxypyr. Maize plants transformed with an AAD-1 gene showed robust crop resistance to aryloxyphenoxypropionate herbicides over four generations and were also not injured by 2,4-D applications at any growth stage. Arabidopsis plants expressing AAD-12 were resistant to 2,4-D as well as triclopyr and fluroxypyr, and transgenic soybean plants expressing AAD-12 maintained field resistance to 2,4-D over five generations. These results show that single AAD transgenes can provide simultaneous resistance to a broad repertoire of agronomically important classes of herbicides, including 2,4-D, with utility in both monocot and dicot crops. These transgenes can help preserve the productivity and environmental benefits of herbicide-resistant crops. PMID:21059954

  16. Can pyramids and seed mixtures delay resistance to Bt crops?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary strategy for delaying evolution of pest resistance to transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) entails refuges of plants that do not produce Bt toxins and thus allow survival of susceptible pests. Recent advances include using refuges together...

  17. Potential application of entomopathogens in resistance management for Bt crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adaptation by pest insects to the bacterium Bacillus thuringiensis (Bt) can alter their susceptibility to other pathogens. As the number of acres planted in crops engineered to produce Bt toxin increases, many key agricultural pests are under strong selection to evolve resistance to Bt. In conjunc...

  18. Risks and Benefits of Glyphosate-Resistant Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate is the most important herbicide since 2,4-D, and biotechnology has magnified its importance. It has a unique target site in the shikimate pathway, 5-enolpyruvyl-shikimate-3-phosphate synthase (EPSPS). Since transgenic, glyphosate-resistant crops (GRCs) were introduced over ten years ago...

  19. Genetically modified crops: environmental and human health concerns.

    PubMed

    Azevedo, João Lúcio; Araujo, Welington Luiz

    2003-11-01

    About 10,000 years ago subsistence farmers started to domesticate plants and it was only much later, after the discovery of the fundaments of genetics, those organisms were submitted to rational genetic improvement mainly by selecting of traits of interest. Breeders used appropriate gene combinations to produce new animal races, plant varieties and hybrids, as well as improved microorganisms such as yeasts. After the introduction of recombinant DNA techniques, the transfer of DNA between species belonging to different genera, families or kingdoms became possible. The release of transgenic plants has aroused debates about several aspects of the environmental and human risks that could result from the introduction of genetically modified crops. Less effort has been dedicated to evaluate the impact of transgenic plants on their associated microorganisms, some of which (e.g. nitrogen-fixing bacteria, mycorrhizal fungi and endophytic microbiota) are extremely important for the survival of the plant. Investigations have been made regarding the horizontal transfer of genetic material between transgenic plants and microorganisms and on the disturbance of useful symbiotic associations between plants and endophytic, epiphytic and rhizosphere communities. In most cases the results do no show any adverse effect of transgenic plants on autochthonous plant-associated microorganisms. Results from our laboratory show small changes caused by genetically modified endophytic bacteria on the indigenous endophytic population of the sweet orange Citrus sinensis. In tests using appropriated fungal strains preliminary results using extracts from transgenic plants indicate that these plants do not affect haploidization, mitotic crossing-over, mutation rate or chromosomal alterations. PMID:14644324

  20. Canopy resistance modelling for crops in contrasting water conditions

    NASA Astrophysics Data System (ADS)

    Rana, G.; Katerji, N.; Mastrorilli, M.

    Although canopy resistance to vapour water transport (r c) depends on climatic conditions and crop water status, standard constant daily values are usually used. Thus models using r c to predict evapotranspiration (ET) fail if applied to water stressed crops. On the other hand, in the scientific literature it is possible to find daily r c models dependent on soil moisture, but, in such cases, these need to be calibrated for each crop and site. Here a “climatic resistance” (r∗) is introduced as function of available energy, vapour pressure deficit and air temperature. Therefore a model of canopy resistance is presented on a hourly and daily time scale, where r c is expressed as function of r∗, aerodynamic resistance, r a, and predawn leaf water potential (PLWP), independently on the soil type. The model has been tested in Southern Italy on grass (reference crop), sorghum, sunflower and soybean and validated in France on soybean, without further calibration. The field crops were submitted to several water stress cycles: PLWP ranged between -0.1 and -1.2 MPa. The experiments showed that this model works well both under and without soil water constraints. On an hourly scale calculated ET in function of PLWP always presented a small underestimation (maximum 6% for soybean in Italy under senescence and water stress); on a daily scale these underestimations are reduced in general. The model test showed that it is independent of the site but depends only on the crop species. On a daily scale the model is presented also with available water (AW) as input, but in this case it needs local calibration. When AW is used as input the model showed an underestimation of 5% and 7% for sorghum and sunflower respectively.

  1. Effects of modified atmosphere on crop productivity and mineral content

    NASA Astrophysics Data System (ADS)

    Chagvardieff, P.; Dimon, B.; Souleimanov, A.; Massimino, D.; Le Bras, S.; Péan, M.; Louche-Teissandier, D.

    1997-01-01

    Wheat, potato, pea and tomato crops were cultivated from seeding to harvest in a controlled and confined growth chamber at elevated CO_2 concentration (3700 muL.L^-1) to examine the effects on biomass production and edible part yields. Different responses to high CO_2 were recorded, ranging from a decline in productivity for wheat, to slight stimulation for potatoes, moderate increase for tomatoes, and very large enhancement for pea. Mineral content in wheat and pea seeds was not greatly modified by the elevated CO_2. Short-term experiments (17 d) were conducted on potato at high (3700 muL.L^-1) and very high (20,000 muL.L^-1) CO_2 concentration and/or low O_2 partial pressure (~ 20,600 muL.L^-1 or 2 kPa). Low O_2 was more effective than high CO_2 in total biomass accumulation, but development was affected: Low O_2 inhibited tuberization, while high CO_2 significantly increased production of tubers.

  2. Metabolomics of Disease Resistance in Crops.

    PubMed

    Arbona, Vicent; Gómez-Cadenas, Aurelio

    2016-01-01

    Plants are continuously exposed to the attack of invasive microorganisms, such as fungi or bacteria, and also viruses. To fight these attackers, plants develop different metabolic and genetic responses whose final outcome is the production of either toxic compounds that kill the pathogen or deter its growth, and/or semiotic molecules that alert other individuals from the same plant species. These molecules are derived from the secondary metabolism and their production is induced upon detection of a pathogen-associated molecular pattern (PAMP). These PAMPs are different molecules that are perceived by the host cell triggering defense responses. PAMP-elicited compounds are highly diverse and specific of every plant species and can be divided into preformed metabolites or phytoanticipins that are converted into toxic molecules upon pathogen perception, and toxic metabolites or phytoalexins that are produced only upon pathogen attack. Moreover, plant volatile emissions are also modified in response to pathogen attack to alert neighboring individuals or to make plants less attractive to pathogen vector arthropods. Plant metabolite profiling techniques have allowed the identification of novel antimicrobial molecules that are induced upon elicitation. However, more studies are required to assess the specific function of metabolites or metabolite blends on plant-microbe interactions. PMID:26364233

  3. Can Pyramids and Seed Mixtures Delay Resistance to Bt Crops?

    PubMed

    Carrière, Yves; Fabrick, Jeffrey A; Tabashnik, Bruce E

    2016-04-01

    The primary strategy for delaying the evolution of pest resistance to transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) entails refuges of plants that do not produce Bt toxins and thus allow survival of susceptible pests. Recent advances include using refuges together with Bt crop 'pyramids' that make two or more Bt toxins effective against the same pest, and planting seed mixtures yielding random distributions of pyramided Bt and non-Bt corn plants within fields. We conclude that conditions often deviate from those favoring the success of pyramids and seed mixtures, particularly against pests with low inherent susceptibility to Bt toxins. For these problematic pests, promising approaches include using larger refuges and integrating Bt crops with other pest management tactics. PMID:26774592

  4. Resistance to Tospoviruses in Vegetable Crops: Epidemiological and Molecular Aspects.

    PubMed

    Turina, Massimo; Kormelink, Richard; Resende, Renato O

    2016-08-01

    During the past three decades, the economic impact of tospoviruses has increased, causing high yield losses in a variety of crops and ornamentals. Owing to the difficulty in combating thrips vectors with insecticides, the best way to limit/prevent tospovirus-induced diseases involves a management strategy that includes virus resistance. This review briefly presents current tospovirus taxonomy, diversity, molecular biology, and cytopathology as an introduction to a more extensive description of the two main resistance genes employed against tospoviruses: the Sw5 gene in tomato and the Tsw in pepper. Natural and experimental resistance-breaking (RB) isolates allowed the identification of the viral avirulence protein triggering each of the two resistance gene products; epidemiology of RB isolates is discussed to reinforce the need for allelic variants and the need to search for new/alternative resistance genes. Ongoing efforts for alternative resistance strategies are described not only for Tomato spotted wilt virus (TSWV) in pepper and tomato but also for other vegetable crops heavily impacted by tospoviruses. PMID:27296139

  5. Challenges in testing genetically modified crops for potential increases in endogenous allergen expression for safety.

    PubMed

    Panda, R; Ariyarathna, H; Amnuaycheewa, P; Tetteh, A; Pramod, S N; Taylor, S L; Ballmer-Weber, B K; Goodman, R E

    2013-02-01

    Premarket, genetically modified (GM) plants are assessed for potential risks of food allergy. The major risk would be transfer of a gene encoding an allergen or protein nearly identical to an allergen into a different food source, which can be assessed by specific serum testing. The potential that a newly expressed protein might become an allergen is evaluated based on resistance to digestion in pepsin and abundance in food fractions. If the modified plant is a common allergenic source (e.g. soybean), regulatory guidelines suggest testing for increases in the expression of endogenous allergens. Some regulators request evaluating endogenous allergens for rarely allergenic plants (e.g. maize and rice). Since allergic individuals must avoid foods containing their allergen (e.g. peanut, soybean, maize, or rice), the relevance of the tests is unclear. Furthermore, no acceptance criteria are established and little is known about the natural variation in allergen concentrations in these crops. Our results demonstrate a 15-fold difference in the major maize allergen, lipid transfer protein between nine varieties, and complex variation in IgE binding to various soybean varieties. We question the value of evaluating endogenous allergens in GM plants unless the intent of the modification was production of a hypoallergenic crop. PMID:23205714

  6. Relevance of Crop Biology for Environmental Risk Assessment of Genetically Modified Crops in Africa.

    PubMed

    Akinbo, Olalekan; Hancock, James F; Makinde, Diran

    2015-01-01

    Knowledge about the crop biology of economic crops in Africa is needed for regulators to accurately review dossiers and conduct comprehensive environmental risk assessments (ERAs). This information allows regulators to decide whether biotech crops present a risk to biodiversity, since crossing between domesticated crops and their wild relatives could affect the adaptations of the wild species. The criteria that should be used in the evaluation of African crops for ERA include growth habit, center of origin, center of genetic diversity, proximity of wild relatives, inter-fertility, mode of pollen dispersal, length of pollen viability, mating system, invasiveness, weediness, mode of propagation, mode of seed dispersal, and length of seed dormancy. In this paper, we discuss the crops being genetic engineered in Africa and describe the crop biology of those with native relatives. PMID:26501055

  7. Relevance of Crop Biology for Environmental Risk Assessment of Genetically Modified Crops in Africa

    PubMed Central

    Akinbo, Olalekan; Hancock, James F.; Makinde, Diran

    2015-01-01

    Knowledge about the crop biology of economic crops in Africa is needed for regulators to accurately review dossiers and conduct comprehensive environmental risk assessments (ERAs). This information allows regulators to decide whether biotech crops present a risk to biodiversity, since crossing between domesticated crops and their wild relatives could affect the adaptations of the wild species. The criteria that should be used in the evaluation of African crops for ERA include growth habit, center of origin, center of genetic diversity, proximity of wild relatives, inter-fertility, mode of pollen dispersal, length of pollen viability, mating system, invasiveness, weediness, mode of propagation, mode of seed dispersal, and length of seed dormancy. In this paper, we discuss the crops being genetic engineered in Africa and describe the crop biology of those with native relatives. PMID:26501055

  8. Taking stock of herbicide-resistant crops ten years after introduction.

    PubMed

    Duke, Stephen O

    2005-03-01

    Since transgenic, bromoxynil-resistant cotton and glufosinate-resistant canola were introduced in 1995, planting of transgenic herbicide-resistant crops has grown substantially, revolutionizing weed management where they have been available. Before 1995, several commercial herbicide-resistant crops were produced by biotechnology through selection for resistance in tissue culture. However, non-transgenic herbicide-resistant crops have had less commercial impact. Since the introduction of glyphosate-resistant soybean in 1996, and the subsequent introduction of other glyphosate-resistant crops, where available, they have taken a commanding share of the herbicide-resistant crop market, especially in soybean, cotton and canola. The high level of adoption of glyphosate-resistant crops by North American farmers has helped to significantly reduce the value of the remaining herbicide market. This has resulted in reduced investment in herbicide discovery, which may be problematic for addressing future weed-management problems. Introduction of herbicide-resistant crops that can be used with selective herbicides has apparently been hindered by the great success of glyphosate-resistant crops. Evolution of glyphosate-resistant weeds and movement of naturally resistant weed species into glyphosate-resistant crop fields will require increases in the use of other herbicides, but the speed with which these processes compromise the use of glyphosate alone is uncertain. The future of herbicide-resistant crops will be influenced by many factors, including alternative technologies, public opinion and weed resistance. Considering the relatively few recent approvals for field testing new herbicide-resistant crops and recent decisions not to grow glyphosate-resistant sugarbeet and wheat, the introduction and adoption of herbicide-resistant crops during the next 10 years is not likely to be as dramatic as in the past 10 years. PMID:15660452

  9. Comparative impact of genetically modified and non modified maize (Zea mays L.) on succeeding crop and associated weed.

    PubMed

    Ibrahim, Muhammad; Ahmed, Naseer; Ullah, Faizan; Shinwari, Zabta Khan; Bano, Asghari

    2016-04-01

    This research work documents the comparative impact of genetically modified (GM) (insect resistance) and non modified maize (Zea maysL.) on growth and germination of succeeding crop wheat (Triticum aestivumL.) and associated weed (Avena fatuaL.). The aqueous extracts of both the GM and non-GM maize exhibited higher phenolic content than that of methanolic extracts. Germination percentage and germination index of wheat was significantly decreased by GM methanolic extract (10%) as well as that of non-GM maize at 3% aqueous extract. Similarly germination percentage of weed (Avena fatuaL.) was significantly reduced by application of 3% and 5% methanolic GM extracts. All extracts of GM maize showed non-significant effect on the number of roots, root length and shoot length per plant but 5% and 10% methanolic extracts of non-GM maize significantly increased the number of roots per plant of wheat seedling. Similarly, 10% methanolic extract of GM maize significantly increased the number of roots per plant of weed seedling. Methanolic extracts of GM and non-GM maize (3% and 5%) significantly decreased the protease activity in wheat as compared to untreated control. PMID:24215059

  10. Tempest in a tea pot: How did the public conversation on genetically modified crops drift so far from the facts?

    PubMed

    Goldstein, Daniel A

    2014-06-01

    The debate over genetically modified (GM) crops has raged in Europe since 1996, but had barely risen above a whisper in the USA until recent labeling debates raised public attention. This article will explain GM crops and traits discuss safety assessment provide a view on safety from authoritative organizations discuss selected issues of current debate, and provide the author's perspective as to why the public debate has drifted so far from scientific reality. The economic and environmental benefits of GM crops are beyond scope, but references are provided. GM food and feed undergo comprehensive assessments using recognized approaches to assure they are as safe as the conventional congener. Issues of food safety and nutrition, unrelated to the GM process, may arise when GM foods display novel components or composition. Unanticipated genetic effects in GM crops appear to be limited in contrast to existing variations among conventional varieties resulting from breeding, mutation, and natural mobile genetic elements. Allergenic potential is assessed when selecting genes for introduction into GM crops and remains a theoretical risk to date. Emerging weed and insect resistance is not unique to GM technology and will require the use of integrated pest management/best practices for pest control. Gene flow from GM crops to wild relatives is limited by existing biological barriers but can at time be a relevant consideration in gene selection and planting practices. Insect-resistant GM crops have significantly reduced use of chemical insecticides and appear to have reduced the incidence of pesticide poisoning in areas where small scale farming and hand application are common. Changes in herbicide patterns are more complex and are evolving over time in response to weed resistance management needs. Recent public debate is driven by a combination of unfounded allegations about the technology and purveyors, pseudoscience, and attempts to apply a strict precautionary principle

  11. Effects of genetically modified herbicide-tolerant cropping systems on weed seedbanks in two years of following crops.

    PubMed

    Firbank, L G; Rothery, P; May, M J; Clark, S J; Scott, R J; Stuart, R C; Boffey, C W H; Brooks, D R; Champion, G T; Haughton, A J; Hawes, C; Heard, M S; Dewar, A M; Perry, J N; Squire, G R

    2006-03-22

    The Farm Scale Evaluations (FSEs) showed that genetically modified herbicide-tolerant (GMHT) cropping systems could influence farmland biodiversity because of their effects on weed biomass and seed production. Recently published results for winter oilseed rape showed that a switch to GMHT crops significantly affected weed seedbanks for at least 2 years after the crops were sown, potentially causing longer-term effects on other taxa. Here, we seek evidence for similar medium-term effects on weed seedbanks following spring-sown GMHT crops, using newly available data from the FSEs. Weed seedbanks following GMHT maize were significantly higher than following conventional varieties for both the first and second years, while by contrast, seedbanks following GMHT spring oilseed rape were significantly lower over this period. Seedbanks following GMHT beet were smaller than following conventional crops in the first year after the crops had been sown, but this difference was much reduced by the second year for reasons that are not clear. These new data provide important empirical evidence for longer-term effects of GMHT cropping on farmland biodiversity. PMID:17148348

  12. Spatiotemporal patterns of non-genetically modified crops in the era of expansion of genetically modified food.

    PubMed

    Sun, Jing; Wu, Wenbin; Tang, Huajun; Liu, Jianguo

    2015-01-01

    Despite heated debates over the safety of genetically modified (GM) food, GM crops have been expanding rapidly. Much research has focused on the expansion of GM crops. However, the spatiotemporal dynamics of non-genetically modified (non-GM) crops are not clear, although they may have significant environmental and agronomic impacts and important policy implications. To understand the dynamics of non-GM crops and to inform the debates among relevant stakeholders, we conducted spatiotemporal analyses of China's major non-GM soybean production region, the Heilongjiang Province. Even though the total soybean planting area decreased from 2005 to 2010, surprisingly, there were hotspots of increase. The results also showed hotspots of loss as well as a large decline in the number and continuity of soybean plots. Since China is the largest non-GM soybean producer in the world, the decline of its major production region may signal the continual decline of global non-GM soybeans. PMID:26380899

  13. Spatiotemporal patterns of non-genetically modified crops in the era of expansion of genetically modified food

    PubMed Central

    Sun, Jing; Wu, Wenbin; Tang, Huajun; Liu, Jianguo

    2015-01-01

    Despite heated debates over the safety of genetically modified (GM) food, GM crops have been expanding rapidly. Much research has focused on the expansion of GM crops. However, the spatiotemporal dynamics of non-genetically modified (non-GM) crops are not clear, although they may have significant environmental and agronomic impacts and important policy implications. To understand the dynamics of non-GM crops and to inform the debates among relevant stakeholders, we conducted spatiotemporal analyses of China’s major non-GM soybean production region, the Heilongjiang Province. Even though the total soybean planting area decreased from 2005 to 2010, surprisingly, there were hotspots of increase. The results also showed hotspots of loss as well as a large decline in the number and continuity of soybean plots. Since China is the largest non-GM soybean producer in the world, the decline of its major production region may signal the continual decline of global non-GM soybeans. PMID:26380899

  14. Insect-resistant biotech crops and their impacts on beneficial arthropods

    PubMed Central

    Gatehouse, A. M. R.; Ferry, N.; Edwards, M. G.; Bell, H. A.

    2011-01-01

    With a projected population of 10 billion by 2050, an immediate priority for agriculture is to achieve increased crop yields in a sustainable and cost-effective way. The concept of using a transgenic approach was realized in the mid-1990s with the commercial introduction of genetically modified (GM) crops. By 2010, the global value of the seed alone was US $11.2 billion, with commercial biotech maize, soya bean grain and cotton valued at approximately US $150 billion. In recent years, it has become evident that insect-resistant crops expressing δ-endotoxin genes from Bacillus thuringiensis have made a significant beneficial impact on global agriculture, not least in terms of pest reduction and improved quality. However, because of the potential for pest populations to evolve resistance, and owing to lack of effective control of homopteran pests, alternative strategies are being developed. Some of these are based on Bacillus spp. or other insect pathogens, while others are based on the use of plant- and animal-derived genes. However, if such approaches are to play a useful role in crop protection, it is desirable that they do not have a negative impact on beneficial organisms at higher trophic levels thus affecting the functioning of the agro-ecosystem. This widely held concern over the ecological impacts of GM crops has led to the extensive examination of the potential effects of a range of transgene proteins on non-target and beneficial insects. The findings to date with respect to both commercial and experimental GM crops expressing anti-insect genes are discussed here, with particular emphasis on insect predators and parasitoids. PMID:21444317

  15. NON-TARGET AND ECOSYSTEM IMPACTS FROM GENETICALLY MODIFIED CROPS CONTAINING PLANT INCORPORATED PROTECTANTS (PIPS)

    EPA Science Inventory

    The risk of unintended and unexpected adverse impacts on non-target organisms and ecosystems is a key issue in environmental risk assessment of PIP crop plants. While there has been considerable examination of the effects of insect resistant crops on certain non-target organisms...

  16. Plant fitness assessment for wild relatives of insect resistant crops.

    PubMed

    Letourneau, Deborah K; Hagen, Joy A

    2009-01-01

    Risk assessments of new insect-resistant crops will need to estimate the potential for increased weediness of wild crop relatives as a consequence of gene flow. When field experiments are precluded by containment concerns, simulation experiments can identify hazards or measure expected differences between GMOs and parental plants. To measure plant fitness consequences of wild plant protection from Bt-susceptible herbivores, we used topical sprays of bacterial Bacillus thuringiensis larvacide (Bt) on Brassica rapa. Spontaneous crosses between B. rapa and Bt cole crops cannot be precluded, especially if adoption of Bt varieties leads to high exposure. We compared survivorship and seed output of B. rapa that were either protected from or exposed to Bt-susceptible Lepidoptera in the various conditions where hybrids are likely to occur: cultivated (disked) soil, uncultivated agricultural field margins, and nearby non-crop habitats (meadows and ruderal areas). The relative effect of herbivore protection varied among years, habitats, and populations of seedlings. In 2003-2004, Bt sprays did not result in lower herbivory on B. rapa, and plant fitness was not increased. However, in 2004-2006 B. rapa seedlings protected from Bt-susceptible herbivores lived 25% longer, on average, than those that were exposed to these herbivores. In addition, an average B. rapa seedling sprayed with Bt throughout its lifetime was twice as likely to produce siliques and had 251% of the seed output of a seedling exposed to herbivores. The fitness advantage of Bt-based plant protection was apparent in 2004-2005 in half the plants that experienced higher herbivory, and for 2005-2006, was more pronounced in agricultural habitats than in meadows with established, perennial vegetation and less disturbance. Positive effects of Bt-based plant protection and greater fitness in disturbed habitats suggest that crop-wild gene flow may benefit weed populations, and that field tests with herbivore exclusion

  17. Benefits of genetically modified crops for the poor: household income, nutrition, and health.

    PubMed

    Qaim, Matin

    2010-11-30

    The potential impacts of genetically modified (GM) crops on income, poverty and nutrition in developing countries continue to be the subject of public controversy. Here, a review of the evidence is given. As an example of a first-generation GM technology, the effects of insect-resistant Bt cotton are analysed. Bt cotton has already been adopted by millions of small-scale farmers, in India, China, and South Africa among others. On average, farmers benefit from insecticide savings, higher effective yields and sizeable income gains. Insights from India suggest that Bt cotton is employment generating and poverty reducing. As an example of a second-generation technology, the likely impacts of beta-carotene-rich Golden Rice are analysed from an ex ante perspective. Vitamin A deficiency is a serious nutritional problem, causing multiple adverse health outcomes. Simulations for India show that Golden Rice could reduce related health problems significantly, preventing up to 40,000 child deaths every year. These examples clearly demonstrate that GM crops can contribute to poverty reduction and food security in developing countries. To realise such social benefits on a larger scale requires more public support for research targeted to the poor, as well as more efficient regulatory and technology delivery systems. PMID:20643233

  18. Proteomics, photosynthesis and salt resistance in crops: An integrative view.

    PubMed

    Silveira, Joaquim A G; Carvalho, Fabricio E L

    2016-06-30

    Salinity is a stressful condition that causes a significant decrease in crop production worldwide. Salt stress affects several photosynthetic reactions, including the modulation of several important proteins. Despite these effects, few molecular-biochemical markers have been identified and evaluated for their importance in improving plant salt resistance. Proteomics is a powerful tool that allows the analysis of multigenic events at the post-translational level that has been widely used to evaluate protein modulation changes in plants exposed to salt stress. However, these studies are frequently fragmented and the results regarding photosynthesis proteins in response to salinity are limited. These constraints could be related to the low number of important photosynthetic proteins differently modulated in response to salinity, as has been commonly revealed by conventional proteomics. In this review, we present an evaluation and perspective on the integrated application of proteomics for the identification of photosynthesis proteins to improve salt resistance. We propose the use of phospho-, thiol- and redox-proteomics, associated with the utilization of isolated chloroplasts or photosynthetic sub-organellar components. This strategy may allow the characterization of essential proteins, providing a better understanding of photosynthesis regulation. Furthermore, this may contribute to the selection of molecular markers to improve salt resistance in crops. PMID:26957143

  19. Crop management and agronomic context of the Farm Scale Evaluations of genetically modified herbicide-tolerant crops.

    PubMed

    Champion, G T; May, M J; Bennett, S; Brooks, D R; Clark, S J; Daniels, R E; Firbank, L G; Haughton, A J; Hawes, C; Heard, M S; Perry, J N; Randle, Z; Rossall, M J; Rothery, P; Skellern, M P; Scott, R J; Squire, G R; Thomas, M R

    2003-11-29

    The Farm Scale Evaluations of genetically modified herbicide-tolerant crops (GMHT) were conducted in the UK from 2000 to 2002 on beet (sugar and fodder), spring oilseed rape and forage maize. The management of the crops studied is described and compared with current conventional commercial practice. The distribution of field sites adequately represented the areas currently growing these crops, and the sample contained sites operated at a range of management intensities, including low intensity. Herbicide inputs were audited, and the active ingredients used and the rates and the timings of applications compared well with current practice for both GMHT and conventional crops. Inputs on sugar beet were lower than, and inputs on spring oilseed rape and forage maize were consistent with, national averages. Regression analysis of herbicide-application strategies and weed emergence showed that inputs applied by farmers increased with weed densities in beet and forage maize. GMHT crops generally received only one herbicide active ingredient per crop, later and fewer herbicide sprays and less active ingredient (for beet and maize) than the conventional treatments. The audit of inputs found no evidence of bias. PMID:14561315

  20. Crop management and agronomic context of the Farm Scale Evaluations of genetically modified herbicide-tolerant crops.

    PubMed Central

    Champion, G T; May, M J; Bennett, S; Brooks, D R; Clark, S J; Daniels, R E; Firbank, L G; Haughton, A J; Hawes, C; Heard, M S; Perry, J N; Randle, Z; Rossall, M J; Rothery, P; Skellern, M P; Scott, R J; Squire, G R; Thomas, M R

    2003-01-01

    The Farm Scale Evaluations of genetically modified herbicide-tolerant crops (GMHT) were conducted in the UK from 2000 to 2002 on beet (sugar and fodder), spring oilseed rape and forage maize. The management of the crops studied is described and compared with current conventional commercial practice. The distribution of field sites adequately represented the areas currently growing these crops, and the sample contained sites operated at a range of management intensities, including low intensity. Herbicide inputs were audited, and the active ingredients used and the rates and the timings of applications compared well with current practice for both GMHT and conventional crops. Inputs on sugar beet were lower than, and inputs on spring oilseed rape and forage maize were consistent with, national averages. Regression analysis of herbicide-application strategies and weed emergence showed that inputs applied by farmers increased with weed densities in beet and forage maize. GMHT crops generally received only one herbicide active ingredient per crop, later and fewer herbicide sprays and less active ingredient (for beet and maize) than the conventional treatments. The audit of inputs found no evidence of bias. PMID:14561315

  1. Glyphosate Effects on Plant Mineral Nutrition, Crop Rhizosphere Microbiota, and Plant Disease in Glyphosate-Resistant Crops

    PubMed Central

    2012-01-01

    Claims have been made recently that glyphosate-resistant (GR) crops sometimes have mineral deficiencies and increased plant disease. This review evaluates the literature that is germane to these claims. Our conclusions are: (1) although there is conflicting literature on the effects of glyphosate on mineral nutrition on GR crops, most of the literature indicates that mineral nutrition in GR crops is not affected by either the GR trait or by application of glyphosate; (2) most of the available data support the view that neither the GR transgenes nor glyphosate use in GR crops increases crop disease; and (3) yield data on GR crops do not support the hypotheses that there are substantive mineral nutrition or disease problems that are specific to GR crops. PMID:23013354

  2. Safety assessment of foods from genetically modified crops in countries with developing economies.

    PubMed

    Delaney, Bryan

    2015-12-01

    Population growth particularly in countries with developing economies will result in a need to increase food production by 70% by the year 2050. Biotechnology has been utilized to produce genetically modified (GM) crops for insect and weed control with benefits including increased crop yield and will also be used in emerging countries. A multicomponent safety assessment paradigm has been applied to individual GM crops to determine whether they as safe as foods from non-GM crops. This paper reviews methods to assess the safety of foods from GM crops for safe consumption from the first generation of GM crops. The methods can readily be applied to new products developed within country and this paper will emphasize the concept of data portability; that safety data produced in one geographic location is suitable for safety assessment regardless of where it is utilized. PMID:26456807

  3. Unintended effects and their detection in genetically modified crops.

    PubMed

    Cellini, F; Chesson, A; Colquhoun, I; Constable, A; Davies, H V; Engel, K H; Gatehouse, A M R; Kärenlampi, S; Kok, E J; Leguay, J-J; Lehesranta, S; Noteborn, H P J M; Pedersen, J; Smith, M

    2004-07-01

    The commercialisation of GM crops in Europe is practically non-existent at the present time. The European Commission has instigated changes to the regulatory process to address the concerns of consumers and member states and to pave the way for removing the current moratorium. With regard to the safety of GM crops and products, the current risk assessment process pays particular attention to potential adverse effects on human and animal health and the environment. This document deals with the concept of unintended effects in GM crops and products, i.e. effects that go beyond that of the original modification and that might impact primarily on health. The document first deals with the potential for unintended effects caused by the processes of transgene insertion (DNA rearrangements) and makes comparisons with genetic recombination events and DNA rearrangements in traditional breeding. The document then focuses on the potential value of evolving "profiling" or "omics" technologies as non-targeted, unbiased approaches, to detect unintended effects. These technologies include metabolomics (parallel analysis of a range of primary and secondary metabolites), proteomics (analysis of polypeptide complement) and transcriptomics (parallel analysis of gene expression). The technologies are described, together with their current limitations. Importantly, the significance of unintended effects on consumer health are discussed and conclusions and recommendations presented on the various approaches outlined. PMID:15123383

  4. Potential resistance management for the sustainable use of insect-resistant genetically modified corn and rice in China.

    PubMed

    Han, Lanzhi; Jiang, Xingfu; Peng, Yufa

    2016-06-01

    Many lines of insect-resistant genetically modified (IRGM) corn and rice containing Bacillus thuringiensis (Bt) insecticidal genes have been developed and undergone different environmental biosafety assessments stages in China, showing robust application prospects. The potential of targeted pests to develop resistance to Bt crops is widespread, which threatens the sustainable utility of IRGM corn and rice. In this study, the potential risks of target pest complexes developing resistance to IRGM corn and rice are evaluated. Theoretical and empirical studies implementing precautionary insect resistance management (IRM) strategies to delay resistance evolution are summarized and challenges to IRM are discussed. Additionally, solutions facing these challenges are proposed. Finally, directions for future studies in developing IRGM corn and rice and IRM plans are discussed. PMID:27436744

  5. Biotech/GM crops in horticulture: plum cv. HoneySweet resistant to plum pox virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercialization of Biotech crops started in 1995. By 2011, genetically modified (GM) crops were grown world-wide on 160 million ha. Only 114.507 ha of GM crops were grown in Europe, of that, 114.490 ha were Bt maize and 17 ha were potato for industrial starch production. Currently, developing c...

  6. Africa's inevitable walk to genetically modified (GM) crops: opportunities and challenges for commercialization.

    PubMed

    Okeno, James A; Wolt, Jeffrey D; Misra, Manjit K; Rodriguez, Lulu

    2013-01-25

    High relative poverty levels in Africa are attributed to the continent's under performing agriculture. Drought, low-yielding crop varieties, pests and diseases, poor soils, low fertilizer use, limited irrigation and lack of modern technologies are among the problems that plague African agriculture. Genetically modified (GM) crops may possess attributes that can help overcome some of these constraints, but have yet to be fully embraced in the mix of technology solutions for African agriculture. Cognizant of this, South Africa, Burkina Faso and Egypt are steadily growing GM crops on a commercial scale. Countries like Kenya, Nigeria, and Uganda are increasingly field-testing these crops with the view to commercialize them. These countries show strong government support for GM technology. Progress by these first adopter nations provides an insight as to how GM crops are increasingly being viewed as one of the ways in which the continent can invigorate the agriculture sector and achieve food security. PMID:22985799

  7. Attitudes of Agricultural Experts Toward Genetically Modified Crops: A Case Study in Southwest Iran.

    PubMed

    Ghanian, Mansour; Ghoochani, Omid M; Kitterlin, Miranda; Jahangiry, Sheida; Zarafshani, Kiumars; Van Passel, Steven; Azadi, Hossein

    2016-04-01

    The production of genetically modified (GM) crops is growing around the world, and with it possible opportunities to combat food insecurity and hunger, as well as solutions to current problems facing conventional agriculture. In this regard the use of GMOs in food and agricultural applications has increased greatly over the past decade. However, the development of GM crops has been a matter of considerable interest and worldwide public controversy. This, in addition to skepticism, has stifled the use of this practice on a large scale in many areas, including Iran. It stands to reason that a greater understanding of this practice could be formed after a review of the existing expert opinions surrounding GM crops. Therefore, the purpose of this study was to analyze the predictors that influence agricultural experts' attitudes toward the development of and policies related to GM crops. Using a descriptive correlational research method, questionnaire data was collected from 65 experts from the Agricultural Organization in the Gotvand district in Southwest Iran. Results indicated that agricultural experts were aware of the environmental benefits and possible risks associated with GM crops. The majority of participants agreed that GM crops could improve food security and accelerate rural development, and were proponents of labeling practices for GM crops. Finally, there was a positive correlation between the perception of benefits and attitudes towards GM crops. PMID:26045394

  8. Innovative farmers and regulatory gatekeepers: Genetically modified crops regulation and adoption in developing countries.

    PubMed

    Sinebo, Woldeyesus; Maredia, Karim

    2016-01-01

    The regulation of genetically modified (GM) crops is a topical issue in agriculture and environment over the past 2 decades. The objective of this paper is to recount regulatory and adoption practices in some developing countries that have successfully adopted GM crops so that aspiring countries may draw useful lessons and best practices for their biosafatey regulatory regimes. The first 11 mega-GM crops growing countries each with an area of more than one million hectares in 2014 were examined. Only five out of the 11 countries had smooth and orderly adoption of these crops as per the regulatory requirement of each country. In the remaining 6 countries (all developing countries), GM crops were either introduced across borders without official authorization, released prior to regulatory approval or unapproved seeds were sold along with the approved ones in violation to the existing regulations. Rapid expansion of transgenic crops over the past 2 decades in the developing world was a result of an intense desire by farmers to adopt these crops irrespective of regulatory roadblocks. Lack of workable biosafety regulatory system and political will to support GM crops encouraged unauthorized access to GM crop varieties. In certain cases, unregulated access in turn appeared to result in the adoption of substandard or spurious technology which undermined performance and productivity. An optimal interaction among the national agricultural innovation systems, biosafety regulatory bodies, biotech companies and high level policy makers is vital in making a workable regulated progress in the adoption of GM crops. Factoring forgone opportunities to farmers to benefit from GM crops arising from overregulation into biosafety risk analysis and decision making is suggested. Building functional biosafety regulatory systems that balances the needs of farmers to access and utilize the GM technology with the regulatory imperatives to ensure adequate safety to the environment and human

  9. Assessment of the safety of foods derived from genetically modified (GM) crops.

    PubMed

    König, A; Cockburn, A; Crevel, R W R; Debruyne, E; Grafstroem, R; Hammerling, U; Kimber, I; Knudsen, I; Kuiper, H A; Peijnenburg, A A C M; Penninks, A H; Poulsen, M; Schauzu, M; Wal, J M

    2004-07-01

    This paper provides guidance on how to assess the safety of foods derived from genetically modified crops (GM crops); it summarises conclusions and recommendations of Working Group 1 of the ENTRANSFOOD project. The paper provides an approach for adapting the test strategy to the characteristics of the modified crop and the introduced trait, and assessing potential unintended effects from the genetic modification. The proposed approach to safety assessment starts with the comparison of the new GM crop with a traditional counterpart that is generally accepted as safe based on a history of human food use (the concept of substantial equivalence). This case-focused approach ensures that foods derived from GM crops that have passed this extensive test-regime are as safe and nutritious as currently consumed plant-derived foods. The approach is suitable for current and future GM crops with more complex modifications. First, the paper reviews test methods developed for the risk assessment of chemicals, including food additives and pesticides, discussing which of these methods are suitable for the assessment of recombinant proteins and whole foods. Second, the paper presents a systematic approach to combine test methods for the safety assessment of foods derived from a specific GM crop. Third, the paper provides an overview on developments in this area that may prove of use in the safety assessment of GM crops, and recommendations for research priorities. It is concluded that the combination of existing test methods provides a sound test-regime to assess the safety of GM crops. Advances in our understanding of molecular biology, biochemistry, and nutrition may in future allow further improvement of test methods that will over time render the safety assessment of foods even more effective and informative. PMID:15123382

  10. Genetically Modified Crops and Nuisance: Exploring the Role of Precaution in Private Law

    ERIC Educational Resources Information Center

    Craik, Neil; Culver, Keith; Siebrasse, Norman

    2007-01-01

    This article critically considers calls for the precautionary principle to inform judicial decision making in a private law context in light of the Hoffman litigation, where it is alleged that the potential for genetic contamination from genetically modified (GM) crops causes an unreasonable interference with the rights of organic farmers to use…

  11. A flame-resistant modified polystyrene

    NASA Technical Reports Server (NTRS)

    Karle, D. W.; Kratze, R. H.; Pacioren, K. L.

    1975-01-01

    Several modified polystyrenes have been developed that are self-extinguishing in air. Information is included in report that also describes molding and fabrication properties, toxicology, and thermal behavior of the polymers.

  12. Perspectives on transgenic, herbicide-resistant crops in the United States almost 20 years after introduction.

    PubMed

    Duke, Stephen O

    2015-05-01

    Herbicide-resistant crops have had a profound impact on weed management. Most of the impact has been by glyphosate-resistant maize, cotton, soybean and canola. Significant economic savings, yield increases and more efficacious and simplified weed management have resulted in widespread adoption of the technology. Initially, glyphosate-resistant crops enabled significantly reduced tillage and reduced the environmental impact of weed management. Continuous use of glyphosate with glyphosate-resistant crops over broad areas facilitated the evolution of glyphosate-resistant weeds, which have resulted in increases in the use of tillage and other herbicides with glyphosate, reducing some of the initial environmental benefits of glyphosate-resistant crops. Transgenic crops with resistance to auxinic herbicides, as well as to herbicides that inhibit acetolactate synthase, acetyl-CoA carboxylase and hydroxyphenylpyruvate dioxygenase, stacked with glyphosate and/or glufosinate resistance, will become available in the next few years. These technologies will provide additional weed management options for farmers, but will not have all of the positive effects (reduced cost, simplified weed management, lowered environmental impact and reduced tillage) that glyphosate-resistant crops had initially. In the more distant future, other herbicide-resistant crops (including non-transgenic ones), herbicides with new modes of action and technologies that are currently in their infancy (e.g. bioherbicides, sprayable herbicidal RNAi and/or robotic weeding) may affect the role of transgenic, herbicide-resistant crops in weed management. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. PMID:25052888

  13. Ecological risk assessment of genetically modified crops based on cellular automata modeling.

    PubMed

    Yang, Jun; Wang, Zhi-Rui; Yang, De-Li; Yang, Qing; Yan, Jun; He, Ming-Feng

    2009-01-01

    The assessment of ecological risk in genetically modified (GM) biological systems is critically important for decision-making and public acceptance. Cellular automata (CA) provide a potential modeling and simulation framework for representing relationships and interspecies interactions both temporally and spatially. In this paper, a simple subsystem contains only four species: crop, target pest, non-target pest and enemy insect, and a three layer arrangement of LxL stochastic cellular automata with a periodic boundary were established. The simulation of this simplified system showed abundant and sufficient complexity in population assembly and densities, suggesting a prospective application in ecological risk assessment of GM crops. PMID:19477260

  14. Crops with target-site herbicide resistance for Orobanche and Striga control.

    PubMed

    Gressel, Jonathan

    2009-05-01

    It is necessary to control root parasitic weeds before or as they attach to the crop. This can only be easily achieved chemically with herbicides that are systemic, or with herbicides that are active in soil. Long-term control can only be attained if the crops do not metabolise the herbicide, i.e. have target-site resistance. Such target-site resistances have allowed foliar applications of herbicides inhibiting enol-pyruvylshikimate phosphate synthase (EPSPS) (glyphosate), acetolactate synthase (ALS) (e.g. chlorsulfuron, imazapyr) and dihydropteroate synthase (asulam) for Orobanche control in experimental conditions with various crops. Large-scale use of imazapyr as a seed dressing of imidazolinone-resistant maize has been commercialised for Striga control. Crops with two target-site resistances will be more resilient to the evolution of resistance in the parasite, if well managed. PMID:19280593

  15. Explaining public resistance to genetically modified corn: an analysis of the distribution of benefits and risks.

    PubMed

    Wu, Felicia

    2004-06-01

    Genetically modified (GM) crops have met with widespread approval among scientists and policy makers in the United States, but public approval of GM crops, both domestically and abroad, is progressing much more slowly. An underlying cause of public wariness may be that both nations and individual consumers do not perceive significant benefits to themselves from GM crops, while fearing the risks they may incur. In this study, an economic analysis is conducted to determine whether the benefits of one type of GM corn, Bt corn (genetically modified to resist damage from the ECB and Southwestern corn borer), outweigh the potential risks; and who the "winners" and "losers" are among stakeholder groups that may be affected by Bt corn. It is found that Bt corn growers, consumers, and industry all benefit from Bt corn adoption, though the purported health and environmental benefits of reducing chemical pesticide usage through Bt corn are negligible. Though the aggregated public benefit is large, the welfare gain to individual consumers is small and may not make up for perceived risks. While environmental and health risks of Bt corn are unlikely, the potential market risks-impacting both the organic corn market and total U.S. corn exports-are found to be significant. Currently, distributional analysis is not a part of regulatory decision making of Bt corn in the United States; yet it may help to explain why decision makers at both the government and individual-consumer levels have failed to embrace Bt corn and other GM crops. PMID:15209940

  16. Metabolism-Based Herbicide Resistance and Cross-Resistance in Crop Weeds: A Threat to Herbicide Sustainability and Global Crop Production1

    PubMed Central

    Yu, Qin; Powles, Stephen

    2014-01-01

    Weedy plant species that have evolved resistance to herbicides due to enhanced metabolic capacity to detoxify herbicides (metabolic resistance) are a major issue. Metabolic herbicide resistance in weedy plant species first became evident in the 1980s in Australia (in Lolium rigidum) and the United Kingdom (in Alopecurus myosuroides) and is now increasingly recognized in several crop-weed species as a looming threat to herbicide sustainability and thus world crop production. Metabolic resistance often confers resistance to herbicides of different chemical groups and sites of action and can extend to new herbicide(s). Cytochrome P450 monooxygenase, glycosyl transferase, and glutathione S-transferase are often implicated in herbicide metabolic resistance. However, precise biochemical and molecular genetic elucidation of metabolic resistance had been stalled until recently. Complex cytochrome P450 superfamilies, high genetic diversity in metabolic resistant weedy plant species (especially cross-pollinated species), and the complexity of genetic control of metabolic resistance have all been barriers to advances in understanding metabolic herbicide resistance. However, next-generation sequencing technologies and transcriptome-wide gene expression profiling are now revealing the genes endowing metabolic herbicide resistance in plants. This Update presents an historical review to current understanding of metabolic herbicide resistance evolution in weedy plant species. PMID:25106819

  17. Unintended compositional changes in genetically modified (GM) crops: 20 years of research.

    PubMed

    Herman, Rod A; Price, William D

    2013-12-01

    The compositional equivalency between genetically modified (GM) crops and nontransgenic comparators has been a fundamental component of human health safety assessment for 20 years. During this time, a large amount of information has been amassed on the compositional changes that accompany both the transgenesis process and traditional breeding methods; additionally, the genetic mechanisms behind these changes have been elucidated. After two decades, scientists are encouraged to objectively assess this body of literature and determine if sufficient scientific uncertainty still exists to continue the general requirement for these studies to support the safety assessment of transgenic crops. It is concluded that suspect unintended compositional effects that could be caused by genetic modification have not materialized on the basis of this substantial literature. Hence, compositional equivalence studies uniquely required for GM crops may no longer be justified on the basis of scientific uncertainty. PMID:23414177

  18. Herbicide-Resistance in Crops and Weeds: A Historical and Current Perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbicides are the principal economic means of weed management on >90% of U.S. farmland. Herbicide-resistant crop cultivars have been used widely since 1995. Pest disciplines and other life sciences have various definitions of resistance that share commonalities. Development of herbicide resistant w...

  19. Plant Defense against Herbivorous Pests: Exploiting Resistance and Tolerance Traits for Sustainable Crop Protection.

    PubMed

    Mitchell, Carolyn; Brennan, Rex M; Graham, Julie; Karley, Alison J

    2016-01-01

    Interactions between plants and insect herbivores are important determinants of plant productivity in managed and natural vegetation. In response to attack, plants have evolved a range of defenses to reduce the threat of injury and loss of productivity. Crop losses from damage caused by arthropod pests can exceed 15% annually. Crop domestication and selection for improved yield and quality can alter the defensive capability of the crop, increasing reliance on artificial crop protection. Sustainable agriculture, however, depends on reduced chemical inputs. There is an urgent need, therefore, to identify plant defensive traits for crop improvement. Plant defense can be divided into resistance and tolerance strategies. Plant traits that confer herbivore resistance typically prevent or reduce herbivore damage through expression of traits that deter pests from settling, attaching to surfaces, feeding and reproducing, or that reduce palatability. Plant tolerance of herbivory involves expression of traits that limit the negative impact of herbivore damage on productivity and yield. Identifying the defensive traits expressed by plants to deter herbivores or limit herbivore damage, and understanding the underlying defense mechanisms, is crucial for crop scientists to exploit plant defensive traits in crop breeding. In this review, we assess the traits and mechanisms underpinning herbivore resistance and tolerance, and conclude that physical defense traits, plant vigor and herbivore-induced plant volatiles show considerable utility in pest control, along with mixed species crops. We highlight emerging approaches for accelerating the identification of plant defensive traits and facilitating their deployment to improve the future sustainability of crop protection. PMID:27524994

  20. Plant Defense against Herbivorous Pests: Exploiting Resistance and Tolerance Traits for Sustainable Crop Protection

    PubMed Central

    Mitchell, Carolyn; Brennan, Rex M.; Graham, Julie; Karley, Alison J.

    2016-01-01

    Interactions between plants and insect herbivores are important determinants of plant productivity in managed and natural vegetation. In response to attack, plants have evolved a range of defenses to reduce the threat of injury and loss of productivity. Crop losses from damage caused by arthropod pests can exceed 15% annually. Crop domestication and selection for improved yield and quality can alter the defensive capability of the crop, increasing reliance on artificial crop protection. Sustainable agriculture, however, depends on reduced chemical inputs. There is an urgent need, therefore, to identify plant defensive traits for crop improvement. Plant defense can be divided into resistance and tolerance strategies. Plant traits that confer herbivore resistance typically prevent or reduce herbivore damage through expression of traits that deter pests from settling, attaching to surfaces, feeding and reproducing, or that reduce palatability. Plant tolerance of herbivory involves expression of traits that limit the negative impact of herbivore damage on productivity and yield. Identifying the defensive traits expressed by plants to deter herbivores or limit herbivore damage, and understanding the underlying defense mechanisms, is crucial for crop scientists to exploit plant defensive traits in crop breeding. In this review, we assess the traits and mechanisms underpinning herbivore resistance and tolerance, and conclude that physical defense traits, plant vigor and herbivore-induced plant volatiles show considerable utility in pest control, along with mixed species crops. We highlight emerging approaches for accelerating the identification of plant defensive traits and facilitating their deployment to improve the future sustainability of crop protection. PMID:27524994

  1. Efficacy of genetically modified Bt toxins alone and in combinations against pink bollworm resistant to Cry1Ac and Cry2Ab

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evolution of resistance in pests threatens the long-term success of transgenic crops that produce insecticidal proteins from Bacillus thuringiensis (Bt). Previous work showed that genetically modified Bt toxins Cry1AbMod and Cry1AcMod effectively countered resistance to native Bt toxins Cry1Ab and ...

  2. Crop advisor perceptions of giant ragweed distribution, herbicide-resistance, and management in the Corn Belt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Giant ragweed has been increasing as a major weed of row crops in North America. We conducted a web-based survey of Certified Crop Advisors in the Corn Belt to determine the current distribution of giant ragweed, the distribution of herbicide resistant populations, and management and ecological fact...

  3. Comparative Analysis of Multiple Disease Resistance in Ryegrass and Cereal Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Perennial ryegrass (Lolium perenne) is one of the most important forage crops in Europe and Australia and also a popular turfgrass in North America. Improvement of resistance to multiple diseases is desirable for such a perennial crop which has long rotation cycles. Quantitative trait loci (QTL) an...

  4. Glyphosate-Resistant Crops and Weeds: Now and in the Future

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate-resistant crops (GRCs) represent more than 80% of the 120 million ha of transgenic crops grown annually world-wide. This single trait has been enthusiastically adopted in soybean, maize, cotton, canola, and sugarbeet in large part because of the economic advantage of the technology, in a...

  5. Outcrossing potential between 11 important genetically modified crops and the Chilean vascular flora.

    PubMed

    Sánchez, Miguel A; Cid, Pablo; Navarrete, Humberto; Aguirre, Carlos; Chacón, Gustavo; Salazar, Erika; Prieto, Humberto

    2016-02-01

    The potential impact of genetically modified (GM) crops on biodiversity is one of the main concerns in an environmental risk assessment (ERA). The likelihood of outcrossing and pollen-mediated gene flow from GM crops and non-GM crops are explained by the same principles and depend primarily on the biology of the species. We conducted a national-scale study of the likelihood of outcrossing between 11 GM crops and vascular plants in Chile by use of a systematized database that included cultivated, introduced and native plant species in Chile. The database included geographical distributions and key biological and agronomical characteristics for 3505 introduced, 4993 native and 257 cultivated (of which 11 were native and 246 were introduced) plant species. Out of the considered GM crops (cotton, soya bean, maize, grape, wheat, rice, sugar beet, alfalfa, canola, tomato and potato), only potato and tomato presented native relatives (66 species total). Introduced relative species showed that three GM groups were formed having: a) up to one introduced relative (cotton and soya bean), b) up to two (rice, grape, maize and wheat) and c) from two to seven (sugar beet, alfalfa, canola, tomato and potato). In particular, GM crops presenting introduced noncultivated relative species were canola (1 relative species), alfalfa (up to 4), rice (1), tomato (up to 2) and potato (up to 2). The outcrossing potential between species [OP; scaled from 'very low' (1) to 'very high' (5)] was developed, showing medium OPs (3) for GM-native relative interactions when they occurred, low (2) for GMs and introduced noncultivated and high (4) for the grape-Vitis vinifera GM-introduced cultivated interaction. This analytical tool might be useful for future ERA for unconfined GM crop release in Chile. PMID:26052925

  6. A case study for assessment of microbial community dynamics in genetically modified Bt cotton crop fields.

    PubMed

    Kapur, Manisha; Bhatia, Ranjana; Pandey, Gunjan; Pandey, Janmejay; Paul, Debarati; Jain, Rakesh K

    2010-08-01

    Bt cotton was the first genetically modified crop approved for use in India. However, only a few studies have been conducted to assess the feasibility of its commercial application. Bt cotton is genetically modified to express a proteinaceous endotoxin (Cry) encoded by cry gene of Bacillus thuringiensis that has specific insecticidal activity against bollworms. Therefore, the amount of pesticides used for growing Bt cotton is postulated to be considerably low as compared to their non-Bt counterparts. Alternatively, it is also speculated that application of a genetically modified crop may alter the bio-geochemical balance of the agriculture field(s). Microbial community composition and dynamics is an important descriptor for assessment of such alterations. In the present study, we have assessed the culturable and non-culturable microbial diversities in Bt cotton and non-Bt cotton soils to determine the ecological consequences of application of Bt cotton. The analyses of microbial community structures indicated that cropping of Bt cotton did not adversely affect the diversity of the microbial communities. PMID:20098990

  7. Modifying enzymes related aminoglycoside: analyses of resistant Acinetobacter isolates

    PubMed Central

    Atasoy, Ali Riza; Ciftci, Ihsan Hakki; Petek, Mustafa

    2015-01-01

    Enzymatic modification of aminoglycosides by nucleotidyltransferases, acetyltransferases and/or phosphotransferases accounts for the majority of aminoglycoside-resistant Acinetobacter isolates. In this study, we investigated the relationship between aminoglycoside resistance and the presence of aminoglycoside-modifying enzymes in Acinetobacter baumannii clinical isolate groups with different resistance profiles. Thirty-two clinical A. baumannii isolates were included in this study. Acinetobacter isolates were divided into 4 groups according to results of susceptibility testing. The presence of genes encoding the following aminoglycoside-modifying enzymes; aph (3’)-V1, aph (3’)-Ia, aac (3)-Ia, aac (3) IIa, aac (6’)-Ih, aac (6’)-Ib and ant (2’)-Ia responsible for resistance was investigated by PCR in all strains. The acetyltransferase (aac (6’)-Ib, aac (3)-Ia) and phosphotransferase (aph (3’)-Ia) gene regions were identified in the first group, which comprised nine imipenem, meropenem, and gentamicin-resistant isolates. The acetyltransferase (aac (6’)-Ib, aac (3)-Ia), phosphotransferase (aph (3’)-VI) and nucleotidyltransferase (ant2-Ia) gene regions were identified in the second group, which was composed of nine imipenem-resistant, meropenem-resistant and gentamicin-sensitive isolates. The acetyltransferase (aac (3)-Ia) and phosphotransferase (aph (3’)-Ia) regions were identified in the fourth group, which comprised eight imipenem-sensitive, meropenem-sensitive and gentamicin-resistant isolates. Modifying enzyme gene regions were not detected in the third group, which was composed of six imipenem, meropenem and gentamicin-sensitive isolates. Our data are consistent with previous reports, with the exception of four isolates. Both acetyltransferases and phosphotransferases were widespread in A. baumannii clinical isolates in our study. However, the presence of the enzyme alone is insufficient to explain the resistance rates. Therefore, the

  8. Cover Crops Reduce Water, Sediment, and Herbicide Loss in Acreage Requiring Tillage to Control Glyphosate-Resistant Weeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate-resistant crops (GRCs) facilitated the adoption of no-tillage cropping systems. No-tillage, that is, omitting all tilling, disking, or harrowing operations, promotes crop residue accumulation on the soil surface. Crop residues protect the soil surface from rainfall impact, impede surfac...

  9. METHODS FOR DETERMINING EXPOSURE TO AND POTENTIAL ECOLOGICAL EFFECTS OF GENE FLOW FROM GENETICALLY MODIFIED CROPS TO COMPATIBLE RELATIVES

    EPA Science Inventory

    SCIENCE QUESTIONS:

    -Does gene flow occur from genetically modified (GM) crop plants to compatible plants?

    -How can it be measured?

    -Are there ecological consequences of GM crop gene flow to plant communities?



    RESEARCH:

    The objectives ...

  10. The global income and production effects of genetically modified (GM) crops 1996-2011.

    PubMed

    Brookes, Graham; Barfoot, Peter

    2013-01-01

    A key part of any assessment of the global value of crop biotechnology in agriculture is an examination of its economic impact at the farm level. This paper follows earlier annual studies which examined economic impacts on yields, key costs of production, direct farm income and effects and impacts on the production base of the four main crops of soybeans, corn, cotton and canola. The commercialization of genetically modified (GM) crops has continued to occur at a rapid rate, with important changes in both the overall level of adoption and impact occurring in 2011. This annual updated analysis shows that there have been very significant net economic benefits at the farm level amounting to $19.8 billion in 2011 and $98.2 billion for the 16 year period (in nominal terms). The majority (51.2%) of these gains went to farmers in developing countries. GM technology have also made important contributions to increasing global production levels of the four main crops, having added 110 million tonnes and 195 million tonnes respectively, to the global production of soybeans and maize since the introduction of the technology in the mid-1990s. PMID:23549349

  11. Pleiotropic effects of herbicide-resistance genes on crop yield: a review.

    PubMed

    Darmency, Henri

    2013-08-01

    The rapid adoption of genetically engineered herbicide-resistant crop varieties (HRCVs)-encompassing 83% of all GM crops and nearly 8% of the worldwide arable area-is due to technical efficiency and higher returns. Other herbicide-resistant varieties obtained from genetic resources and mutagenesis have also been successfully released. Although the benefit for weed control is the main criteria for choosing HRCVs, the pleiotropic costs of genes endowing resistance have rarely been investigated in crops. Here the available data of comparisons between isogenic resistant and susceptible varieties are reviewed. Pleiotropic harmful effects on yield are reported in half of the cases, mostly with resistance mechanisms that originate from genetic resources and mutagenesis (atrazine in oilseed rape and millet, trifluralin in millet, imazamox in cotton) rather than genetic engineering (chlorsulfuron and glufosinate in some oilseed rape varieties, glyphosate in soybean). No effect was found for sethoxydim and bromoxynil resistance. Variable minor effects were found for imazamox, chlorsulfuron, glufosinate and glyphosate resistance. The importance of the breeding plan and the genetic background on the emergence of these effects is pointed out. Breeders' efforts to produce better varieties could compensate for the yield loss, which eliminates any possibility of formulating generic conclusions on pleiotropic effects that can be applied to all resistant crops. PMID:23457026

  12. Subtle effects of herbicide use in the context of genetically modified crops: a case study with glyphosate (Roundup).

    PubMed

    Blackburn, Lynda G; Boutin, Céline

    2003-01-01

    Research on the effects of glyphosate and seed germination spans 30 years. Despite several studies reporting detrimental effects of the herbicide on seedling germination and growth, glyphosate is still being registered for use as a weed killer and preharvest desiccant. Its nonselective nature and low chance of species developing resistance has lead to the development of genetically modified crops tolerant to the herbicide which also raises concerns about increased reliance on herbicide use, and subtle ecological impact. This paper presents the result of a literature review on past studies mostly, on crop species, and the results of a new experiment performed with emphasis on noncrop species. The new experimental part attempted to determine whether glyphosate (Roundup) would have an effect on the germination and growth of the F1 generation of seeds produced by plants sprayed with the herbicide. It was designed to mirror spray drift which might affect noncrop plants in nontarget drift zones. Of the 11 species tested using treatments of 0% (control), 1%, 10% or 100% of a 890 g a.i./ha label rate solution sprayed near seed maturity, seven showed a significant effect of the glyphosate treatment on germination and/or growth characteristics. Results of this experiment together with several previous studies reviewed in this paper suggest that there are significant effects to keep in mind when using herbicides such as glyphosate as severe ecological changes could occur. PMID:12739874

  13. Are Herbicide Resistant Crops The Answer To Controlling Cascuta?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Herbicide tolerant crop technology could provide new management strategies for the control of parasitic plants. Three herbicide-tolerant oilseed rape genotypes were used to examine the response of attached C. campestris to glyphosate, imazamox and glufosinate. C. campestris was allowed to establi...

  14. Mini Review: Potential Applications of Non-host Resistance for Crop Improvement.

    PubMed

    Lee, Seonghee; Whitaker, Vance M; Hutton, Samuel F

    2016-01-01

    Plant breeding for disease resistance is crucial to sustain global crop production. For decades, plant breeders and researchers have extensively used host plant resistance genes (R-genes) to develop disease resistant cultivars. However, the general instability of R-genes in crop cultivars when challenged with diverse pathogen populations emphasizes the need for more stable means of resistance. Alternatively, non-host resistance is recognized as the most durable, broad-spectrum form of resistance against the majority of potential pathogens in plants and has gained great attention as an alternative target for managing resistance. While transgenic approaches have been utilized to transfer non-host resistance to host species, conventional breeding applications have been more elusive. Nevertheless, avenues for discovery and deployment of genetic loci for non-host resistance via hybridization are increasingly abundant, particularly when transferring genes among closely related species. In this mini review, we discuss current and developing applications of non-host resistance for crop improvement with a focus on the overlap between host and non-host mechanisms and the potential impacts of new technology. PMID:27462329

  15. Mini Review: Potential Applications of Non-host Resistance for Crop Improvement

    PubMed Central

    Lee, Seonghee; Whitaker, Vance M.; Hutton, Samuel F.

    2016-01-01

    Plant breeding for disease resistance is crucial to sustain global crop production. For decades, plant breeders and researchers have extensively used host plant resistance genes (R-genes) to develop disease resistant cultivars. However, the general instability of R-genes in crop cultivars when challenged with diverse pathogen populations emphasizes the need for more stable means of resistance. Alternatively, non-host resistance is recognized as the most durable, broad-spectrum form of resistance against the majority of potential pathogens in plants and has gained great attention as an alternative target for managing resistance. While transgenic approaches have been utilized to transfer non-host resistance to host species, conventional breeding applications have been more elusive. Nevertheless, avenues for discovery and deployment of genetic loci for non-host resistance via hybridization are increasingly abundant, particularly when transferring genes among closely related species. In this mini review, we discuss current and developing applications of non-host resistance for crop improvement with a focus on the overlap between host and non-host mechanisms and the potential impacts of new technology. PMID:27462329

  16. The current status and environmental impacts of glyphosate-resistant crops: a review.

    PubMed

    Cerdeira, Antonio L; Duke, Stephen O

    2006-01-01

    Glyphosate [N-(phosphonomethyl) glycine]-resistant crops (GRCs), canola (Brassica napus L.), cotton (Gossypium hirsutum L.), maize (Zea mays L.), and soybean [Glycine max (L.) Merr.] have been commercialized and grown extensively in the Western Hemisphere and, to a lesser extent, elsewhere. Glyphosate-resistant cotton and soybean have become dominant in those countries where their planting is permitted. Effects of glyphosate on contamination of soil, water, and air are minimal, compared to some of the herbicides that they replace. No risks have been found with food or feed safety or nutritional value in products from currently available GRCs. Glyphosate-resistant crops have promoted the adoption of reduced- or no-tillage agriculture in the USA and Argentina, providing a substantial environmental benefit. Weed species in GRC fields have shifted to those that can more successfully withstand glyphosate and to those that avoid the time of its application. Three weed species have evolved resistance to glyphosate in GRCs. Glyphosate-resistant crops have greater potential to become problems as volunteer crops than do conventional crops. Glyphosate resistance transgenes have been found in fields of canola that are supposed to be non-transgenic. Under some circumstances, the largest risk of GRCs may be transgene flow (introgression) from GRCs to related species that might become problems in natural ecosystems. Glyphosate resistance transgenes themselves are highly unlikely to be a risk in wild plant populations, but when linked to transgenes that may impart fitness benefits outside of agriculture (e.g., insect resistance), natural ecosystems could be affected. The development and use of failsafe introgression barriers in crops with such linked genes is needed. PMID:16899736

  17. Relevance of Bt toxin interaction studies for environmental risk assessment of genetically modified crops.

    PubMed

    De Schrijver, Adinda; De Clercq, Patrick; de Maagd, Ruud A; van Frankenhuyzen, Kees

    2015-12-01

    In recent years, different Bacillus thuringiensis (Bt) toxin-encoding genes have been combined or 'stacked' in genetically modified (GM) crops. Synergism between Bt proteins may occur and thereby increase the impact of the stacked GM event on nontarget invertebrates compared to plants expressing a single Bt gene. On the basis of bioassay data available for Bt toxins alone or in combination, we argue that the current knowledge of Bt protein interactions is of limited relevance in environmental risk assessment (ERA). PMID:26032006

  18. Resistance Management Monitoring For the US Corn Crop

    EPA Science Inventory

    Significant increases in genetically modified corn planting are expected for future planted acreages approaching 80% of total corn plantings anticipated by 2009. As demand increases, incidence of farmer non-compliance with mandated non-genetically modified refuge is likely to in...

  19. Endophytic fungi: resource for gibberellins and crop abiotic stress resistance.

    PubMed

    Khan, Abdul Latif; Hussain, Javid; Al-Harrasi, Ahmed; Al-Rawahi, Ahmed; Lee, In-Jung

    2015-03-01

    The beneficial effects of endophytes on plant growth are important for agricultural ecosystems because they reduce the need for fertilizers and decrease soil and water pollution while compensating for environmental perturbations. Endophytic fungi are a novel source of bioactive secondary metabolites; moreover, recently they have been found to produce physiologically active gibberellins as well. The symbiosis of gibberellins producing endophytic fungi with crops can be a promising strategy to overcome the adverse effects of abiotic stresses. The association of such endophytes has not only increased plant biomass but also ameliorated plant-growth during extreme environmental conditions. Endophytic fungi represent a trove of unexplored biodiversity and a frequently overlooked component of crop ecology. The present review describes the role of gibberellins producing endophytic fungi, suggests putative mechanisms involved in plant endophyte stress interactions and discusses future prospects in this field. PMID:23984800

  20. Ecological Compatibility of GM Crops and Biological Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insect-resistant and herbicide-tolerant genetically modified (GM) crops pervade many modern cropping systems, and present challenges and opportunities for developing biologically-based pest management programs. Interactions between biological control agents (insect predators, parasitoids, and pathog...

  1. The theoretical relationship between foliage temperature and canopy resistance in sparse crops

    NASA Technical Reports Server (NTRS)

    Shuttleworth, W. James; Gurney, Robert J.

    1990-01-01

    One-dimensional, sparse-crop interaction theory is reformulated to allow calculation of the canopy resistance from measurements of foliage temperature. A submodel is introduced to describe eddy diffusion within the canopy which provides a simple, empirical simulation of the reported behavior obtained from a second-order closure model. The sensitivity of the calculated canopy resistance to the parameters and formulas assumed in the model is investigated. The calculation is shown to exhibit a significant but acceptable sensitivity to extreme changes in canopy aerodynamics, and to changes in the surface resistance of the substrate beneath the canopy at high and intermediate values of leaf area index. In very sparse crops changes in the surface resistance of the substrate are shown to contaminate the calculated canopy resistance, tending to amplify the apparent response to changes in water availability. The theory is developed to allow the use of a measurement of substrate temperature as an option to mitigate this contamination.

  2. Genetic basis and detection of unintended effects in genetically modified crop plants.

    PubMed

    Ladics, Gregory S; Bartholomaeus, Andrew; Bregitzer, Phil; Doerrer, Nancy G; Gray, Alan; Holzhauser, Thomas; Jordan, Mark; Keese, Paul; Kok, Esther; Macdonald, Phil; Parrott, Wayne; Privalle, Laura; Raybould, Alan; Rhee, Seung Yon; Rice, Elena; Romeis, Jörg; Vaughn, Justin; Wal, Jean-Michel; Glenn, Kevin

    2015-08-01

    In January 2014, an international meeting sponsored by the International Life Sciences Institute/Health and Environmental Sciences Institute and the Canadian Food Inspection Agency titled "Genetic Basis of Unintended Effects in Modified Plants" was held in Ottawa, Canada, bringing together over 75 scientists from academia, government, and the agro-biotech industry. The objectives of the meeting were to explore current knowledge and identify areas requiring further study on unintended effects in plants and to discuss how this information can inform and improve genetically modified (GM) crop risk assessments. The meeting featured presentations on the molecular basis of plant genome variability in general, unintended changes at the molecular and phenotypic levels, and the development and use of hypothesis-driven evaluations of unintended effects in assessing conventional and GM crops. The development and role of emerging "omics" technologies in the assessment of unintended effects was also discussed. Several themes recurred in a number of talks; for example, a common observation was that no system for genetic modification, including conventional methods of plant breeding, is without unintended effects. Another common observation was that "unintended" does not necessarily mean "harmful". This paper summarizes key points from the information presented at the meeting to provide readers with current viewpoints on these topics. PMID:25716164

  3. Crop systems and plant roots can modify the soil water holding capacity

    NASA Astrophysics Data System (ADS)

    Doussan, Claude; Cousin, Isabelle; Berard, Annette; Chabbi, Abad; Legendre, Laurent; Czarnes, Sonia; Toussaint, Bruce; Ruy, Stéphane

    2015-04-01

    At the interface between atmosphere and deep sub-soil, the root zone plays a major role in regulating the flow of water between major compartments: groundwater / surface / atmosphere (drainage, runoff, evapotranspiration). This role of soil as regulator/control of water fluxes, but also as a supporting medium to plant growth, is strongly dependent on the hydric properties of the soil. In turn, the plant roots growing in the soil can change its structure; both in the plow layer and in the deeper horizons and, therefore, could change the soil properties, particularly hydric properties. Such root-related alteration of soil properties can be linked to direct effect of roots such as soil perforation during growth, aggregation of soil particles or indirect effects such as the release of exudates by roots that could modify the properties of water or of soil particles. On an another hand, the rhizosphere, the zone around roots influenced by the activity of root and associated microorganisms, could have a high influence on hydric properties, particularly the water retention. To test if crops and plant roots rhizosphere may have a significant effect on water retention, we conducted various experiment from laboratory to field scales. In the lab, we tested different soil and species for rhizospheric effect on soil water retention. Variation in available water content (AWC) between bulk and rhizospheric soil varied from non-significant to a significant increase (to about 16% increase) depending on plant species and soil type. In the field, the alteration of water retention by root systems was tested in different pedological settings for a Maize crop inoculated or not with the bacteria Azospirillum spp., known to alter root structure, growth and morphology. Again, a range of variation in AWC was evidenced, with significant increase (~30%) in some soil types, but more linked to innoculated/non-innoculated plants rather than to a difference between rhizospheric and bulk soil

  4. Novel aerobic tetracycline resistance gene that chemically modifies tetracycline.

    PubMed Central

    Speer, B S; Salyers, A A

    1989-01-01

    A tetracycline resistance gene that was found originally on the Bacteroides plasmid pBF4 confers resistance on Escherichia coli but only when cells are growing aerobically. When E. coli EM24 carrying this aerobic tetracycline resistance (*Tcr) gene is grown in medium containing tetracycline, the resulting spent medium is no longer toxic to tetracycline-sensitive (Tcs) E. coli EM24 (B.S. Speer and A.A. Salyers, J. Bacteriol. 170: 1423-1429, 1988). To determine whether the *Tcr gene product modified tetracycline, we characterized the material resulting from incubation of E. coli (*Tcr) with tetracycline. When [7-3H(N)]tetracycline was added to cultures of E. coli (*Tcr), at least 90% of the label was recovered in the extracellular fluid. Therefore, tetracycline was not being sequestered by the cells. The labeled material behaved similarly to tetracycline with respect to solubility in various organic solvents. However, the UV-visible light spectrum had a single peak at 258 nm, whereas the tetracycline spectrum had a peak at 364 nm. The labeled material also had a faster migration rate than did tetracycline on thin-layer plates in a solvent system of butanol-methanol-10% citric acid (4:1:2, vol/vol/vol) and was separable from tetracycline by reverse-phase high-pressure liquid chromatography, using an acetronitrile-0.1% trifluoroacetic acid solvent system. These results demonstrate that the *Tcr gene product chemically modifies tetracycline. The *Tcr gene is the first example of a chemically modifying tetracycline resistance mechanism. PMID:2644186

  5. Glyphosate degradation in glyphosate-resistant crops and weeds and susceptible crops and weeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High levels of aminomethylphosphonic acid (AMPA), the main glyphosate metabolite, have been found in glyphosate-treated, glyphosate-resistant (GR) soybean, apparently due to plant glyphosate oxidoreductase (GOX) – like activity. AMPA is mildly phytotoxic, and under some conditions the AMPA accumula...

  6. Glyphosate-resistant weeds of South American cropping systems: an overview.

    PubMed

    Vila-Aiub, Martin M; Vidal, Ribas A; Balbi, Maria C; Gundel, Pedro E; Trucco, Frederico; Ghersa, Claudio M

    2008-04-01

    Herbicide resistance is an evolutionary event resulting from intense herbicide selection over genetically diverse weed populations. In South America, orchard, cereal and legume cropping systems show a strong dependence on glyphosate to control weeds. The goal of this report is to review the current knowledge on cases of evolved glyphosate-resistant weeds in South American agriculture. The first reports of glyphosate resistance include populations of highly diverse taxa (Lolium multiflorum Lam., Conyza bonariensis L., C. canadensis L.). In all instances, resistance evolution followed intense glyphosate use in fruit fields of Chile and Brazil. In fruit orchards from Colombia, Parthenium hysterophorus L. has shown the ability to withstand high glyphosate rates. The recent appearance of glyphosate-resistant Sorghum halepense L. and Euphorbia heterophylla L. in glyphosate-resistant soybean fields of Argentina and Brazil, respectively, is of major concern. The evolution of glyphosate resistance has clearly taken place in those agroecosystems where glyphosate exerts a strong and continuous selection pressure on weeds. The massive adoption of no-till practices together with the utilization of glyphosate-resistant soybean crops are factors encouraging increase in glyphosate use. This phenomenon has been more evident in Argentina and Brazil. The exclusive reliance on glyphosate as the main tool for weed management results in agroecosystems biologically more prone to glyphosate resistance evolution. PMID:18161884

  7. Identification of tree-crop rootstocks with resistance to Armillaria root disease.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Armillaria root disease attacks a broad range of tree crops in California. Instead of re-tooling ineffective conventional controls, namely soil fumigation, we focused on identification of Armillaria-resistant Juglans rootstocks, as part of a collaborative project to identify rootstocks with resistan...

  8. Glyphosate-Resistant Crop Production Systems: Impact on Weed Species Shifts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 1996, transgenic GR canola and GR soybean containing a bacterial gene that imparts resistance to glyphosate were commercialized in the US. Later, GR cotton (1997) and GR corn (1998) were commercialized for planting in the US. GRCs enabled in-crop postemergence application of glyphosate. The effec...

  9. Effects of Glyphosate-resistant Crop Cultivation on Soil and Water Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic glyphosate-resistant crops (GRCs) have been commercialized and grown extensively in the Western Hemisphere and, to a lesser extent, elsewhere. GRCs have generally become dominant in those countries where they can be grown. Potential effects of glyphosate on soil and water are minimal, com...

  10. Plant adaptation to acid soils: the molecular basis for crop aluminum resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aluminum (Al) toxicity on acid soils is a significant limitation to crop production worldwide, as approximately 50% of the world’s potentially arable soils are acidic. Because acid soils are such an important constraint to agriculture, understanding the mechanisms and genes conferring resistance to ...

  11. Integrating soil conservation practices and glyphosate-resistant crops: impacts on soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    From an environmental perspective, conservation management (CM) practices such as reduced tillage help improve soil conditions. Literature concerning effects of CM on the environment is building, and many of those studies include glyphosate resistant crops (GRC) or glyphosate as a management compon...

  12. DNA Barcoding Simplifies Environmental Risk Assessment of Genetically Modified Crops in Biodiverse Regions

    PubMed Central

    Nzeduru, Chinyere V.; Ronca, Sandra; Wilkinson, Mike J.

    2012-01-01

    Transgenes encoding for insecticidal crystal (Cry) proteins from the soil-dwelling bacterium Bacillus Thuringiensis have been widely introduced into Genetically Modified (GM) crops to confer protection against insect pests. Concern that these transgenes may also harm beneficial or otherwise valued insects (so-called Non Target Organisms, NTOs) represents a major element of the Environmental Risk Assessments (ERAs) used by all countries prior to commercial release. Compiling a comprehensive list of potentially susceptible NTOs is therefore a necessary part of an ERA for any Cry toxin-containing GM crop. In partly-characterised and biodiverse countries, NTO identification is slowed by the need for taxonomic expertise and time to enable morphological identifications. This limitation represents a potentially serious barrier to timely adoption of GM technology in some developing countries. We consider Bt Cry1A cowpea (Vigna unguiculata) in Nigeria as an exemplar to demonstrate how COI barcoding can provide a simple and cost-effective means of addressing this problem. Over a period of eight weeks, we collected 163 insects from cowpea flowers across the agroecological and geographic range of the crop in Nigeria. These individuals included 32 Operational Taxonomic Units (OTUs) spanning four Orders and that could mostly be assigned to genus or species level. They included 12 Lepidopterans and two Coleopterans (both potentially sensitive to different groups of Cry proteins). Thus, barcode-assisted diagnoses were highly harmonised across groups (typically to genus or species level) and so were insensitive to expertise or knowledge gaps. Decisively, the entire study was completed within four months at a cost of less than 10,000 US$. The broader implications of the findings for food security and the capacity for safe adoption of GM technology are briefly explored. PMID:22567120

  13. DNA barcoding simplifies environmental risk assessment of genetically modified crops in biodiverse regions.

    PubMed

    Nzeduru, Chinyere V; Ronca, Sandra; Wilkinson, Mike J

    2012-01-01

    Transgenes encoding for insecticidal crystal (Cry) proteins from the soil-dwelling bacterium Bacillus Thuringiensis have been widely introduced into Genetically Modified (GM) crops to confer protection against insect pests. Concern that these transgenes may also harm beneficial or otherwise valued insects (so-called Non Target Organisms, NTOs) represents a major element of the Environmental Risk Assessments (ERAs) used by all countries prior to commercial release. Compiling a comprehensive list of potentially susceptible NTOs is therefore a necessary part of an ERA for any Cry toxin-containing GM crop. In partly-characterised and biodiverse countries, NTO identification is slowed by the need for taxonomic expertise and time to enable morphological identifications. This limitation represents a potentially serious barrier to timely adoption of GM technology in some developing countries. We consider Bt Cry1A cowpea (Vigna unguiculata) in Nigeria as an exemplar to demonstrate how COI barcoding can provide a simple and cost-effective means of addressing this problem. Over a period of eight weeks, we collected 163 insects from cowpea flowers across the agroecological and geographic range of the crop in Nigeria. These individuals included 32 Operational Taxonomic Units (OTUs) spanning four Orders and that could mostly be assigned to genus or species level. They included 12 Lepidopterans and two Coleopterans (both potentially sensitive to different groups of Cry proteins). Thus, barcode-assisted diagnoses were highly harmonised across groups (typically to genus or species level) and so were insensitive to expertise or knowledge gaps. Decisively, the entire study was completed within four months at a cost of less than 10,000 US$. The broader implications of the findings for food security and the capacity for safe adoption of GM technology are briefly explored. PMID:22567120

  14. Low Temperature and Modified Atmosphere: Hurdles for Antibiotic Resistance Transfer?

    PubMed

    Van Meervenne, Eva; Van Coillie, Els; Van Weyenberg, Stephanie; Boon, Nico; Herman, Lieve; Devlieghere, Frank

    2015-12-01

    Food is an important dissemination route for antibiotic-resistant bacteria. Factors used during food production and preservation may contribute to the transfer of antibiotic resistance genes, but research on this subject is scarce. In this study, the effect of temperature (7 to 37°C) and modified atmosphere packaging (air, 50% CO2-50% N2, and 100% N2) on antibiotic resistance transfer from Lactobacillus sakei subsp. sakei to Listeria monocytogenes was evaluated. Filter mating was performed on nonselective agar plates with high-density inocula. A more realistic setup was created by performing modified atmosphere experiments on cooked ham using high-density and low-density inocula. Plasmid transfer was observed between 10 and 37°C, with plasmid transfer also observed at 7°C during a prolonged incubation period. When high-density inocula were used, transconjugants were detected, both on agar plates and cooked ham, under the three atmospheres (air, 50% CO2-50% N2, and 100% N2) at 7°C. This yielded a median transfer ratio (number of transconjugants/number of recipients) with an order of magnitude of 10(-4) to 10(-6). With low-density inocula, transfer was only detected under the 100% N2 atmosphere after 10-day incubation at 7°C, yielding a transfer ratio of 10(-5). Under this condition, the highest bacterial density was obtained. The results indicate that low temperature and modified atmosphere packaging, two important hurdles in the food industry, do not necessarily prevent plasmid transfer from Lactobacillus sakei subsp. sakei to Listeria monocytogenes. PMID:26613914

  15. Development and Application of Loop-Mediated Isothermal Amplification Assays for Rapid Visual Detection of cry2Ab and cry3A Genes in Genetically-Modified Crops

    PubMed Central

    Li, Feiwu; Yan, Wei; Long, Likun; Qi, Xing; Li, Congcong; Zhang, Shihong

    2014-01-01

    The cry2Ab and cry3A genes are two of the most important insect-resistant exogenous genes and had been widely used in genetically-modified crops. To develop more effective alternatives for the quick identification of genetically-modified organisms (GMOs) containing these genes, a rapid and visual loop-mediated isothermal amplification (LAMP) method to detect the cry2Ab and cry3A genes is described in this study. The LAMP assay can be finished within 60 min at an isothermal condition of 63 °C. The derived LAMP products can be obtained by a real-time turbidimeter via monitoring the white turbidity or directly observed by the naked eye through adding SYBR Green I dye. The specificity of the LAMP assay was determined by analyzing thirteen insect-resistant genetically-modified (GM) crop events with different Bt genes. Furthermore, the sensitivity of the LAMP assay was evaluated by diluting the template genomic DNA. Results showed that the limit of detection of the established LAMP assays was approximately five copies of haploid genomic DNA, about five-fold greater than that of conventional PCR assays. All of the results indicated that this established rapid and visual LAMP assay was quick, accurate and cost effective, with high specificity and sensitivity. In addition, this method does not need specific expensive instruments or facilities, which can provide a simpler and quicker approach to detecting the cry2Ab and cry3A genes in GM crops, especially for on-site, large-scale test purposes in the field. PMID:25167136

  16. Development and application of loop-mediated isothermal amplification assays for rapid visual detection of cry2Ab and cry3A genes in genetically-modified crops.

    PubMed

    Li, Feiwu; Yan, Wei; Long, Likun; Qi, Xing; Li, Congcong; Zhang, Shihong

    2014-01-01

    The cry2Ab and cry3A genes are two of the most important insect-resistant exogenous genes and had been widely used in genetically-modified crops. To develop more effective alternatives for the quick identification of genetically-modified organisms (GMOs) containing these genes, a rapid and visual loop-mediated isothermal amplification (LAMP) method to detect the cry2Ab and cry3A genes is described in this study. The LAMP assay can be finished within 60 min at an isothermal condition of 63 °C. The derived LAMP products can be obtained by a real-time turbidimeter via monitoring the white turbidity or directly observed by the naked eye through adding SYBR Green I dye. The specificity of the LAMP assay was determined by analyzing thirteen insect-resistant genetically-modified (GM) crop events with different Bt genes. Furthermore, the sensitivity of the LAMP assay was evaluated by diluting the template genomic DNA. Results showed that the limit of detection of the established LAMP assays was approximately five copies of haploid genomic DNA, about five-fold greater than that of conventional PCR assays. All of the results indicated that this established rapid and visual LAMP assay was quick, accurate and cost effective, with high specificity and sensitivity. In addition, this method does not need specific expensive instruments or facilities, which can provide a simpler and quicker approach to detecting the cry2Ab and cry3A genes in GM crops, especially for on-site, large-scale test purposes in the field. PMID:25167136

  17. Investigating Root Zone Soil Moisture Using Electrical Resistivity and Crop Modeling

    NASA Astrophysics Data System (ADS)

    Diker, K.; Van Dam, R. L.; Hyndman, D. W.; Kendall, A. D.; Bhardwaj, A. K.; Hamilton, S. K.; Basso, B.

    2011-12-01

    An accurate understanding of soil moisture variability is critical for agroecological modeling and for understanding the implications of climate change for agriculture. In recent years, electrical resistivity (ER) methods have successfully been used to characterize soil moisture in a range of environments, but there remains a need to better link these data to climate variability, soil textural properties, and vegetation and root dynamics. We present results for a novel ER measurement system at the Great Lakes Bioenergy Research Center (GLBRC) in southwest Michigan. Permanent multi-electrode arrays were installed beneath a range of annual and perennial biofuel crop types including corn, soybean, various grasses, and poplars. The ER arrays provide both high spatial resolution 2D and high temporal resolution 1D apparent resistivity data (4 week and 2 hour intervals, respectively). These data, along with a forward simulation of electrical resistivity in the soil column, are used to calibrate and refine root growth dynamics modules within the crop growth and soil hydrologic model SALUS (System Approach to Land Use Sustainability). Simulations are compared to 1D TDR-inferred soil moisture data. Variability in root zone dynamics among different biofuel cropping systems is explored. Total water use and efficiency, along with profile root water extraction, vary considerably among the crops.

  18. Dispersal of viable row-crop seeds of commercial agriculture by farmland birds: implication for genetically modified crops.

    PubMed

    Cummings, John L; Handley, Levis W; Macbryde, Bruce; Tupper, Shelagh K; Werner, Scott J; Byram, Zachary J

    2008-01-01

    To address some concerns about the expansion of genetically engineered pharmaceutical and industrial crops to outdoor plantings and potential impacts on the human food supply, we determined whether commercial agriculture seeds of maize or corn Zea mays L., barley Hordeum vulgare L., safflower Carthamus tinctorius L. and rice Oryza sativa L. are digested or pass viably through the digestive tract, or are transported externally, by captive mallard ducks Anas platyrhynchos L., ring-necked pheasants Phasianus colchicus L., red-winged blackbirds Agelaius phoeniceus (L.) and rock pigeons Columba livia Gmelin (with the exception of whole maize seeds which were too large to feed to the blackbirds). These crop seeds, whether free-fed or force-fed, did not pass through the digestive tract of these bird species. The birds nonetheless did retain viable seeds in the esophagus/crop and gizzard for several hours. For example, after foraging for 6 h, mallards had retained an average of 228 +/- 112 barley seeds and pheasants 192 +/- 78 in the esophagus/crop, and their germination rates were 93 and 50%, respectively. Birds externally transported seeds away from the feeding location, but in only four instances were seeds found attached to their muddy feet or legs and in no case to feathers. Risk of such crop seeds germinating, establishing and reproducing off site after transport by a bird (externally or internally) or movement of a carcass by a predator, will depend greatly on the crop and bird species, location, environmental conditions (including soil characteristics), timing, and seed condition. PMID:19081011

  19. Cross-resistance to toxins used in pyramided Bt crops and resistance to Bt sprays in Helicoverpa zea.

    PubMed

    Welch, Kara L; Unnithan, Gopalan C; Degain, Ben A; Wei, Jizhen; Zhang, Jie; Li, Xianchun; Tabashnik, Bruce E; Carrière, Yves

    2015-11-01

    To delay evolution of resistance by insect pests, farmers are rapidly increasing their use of transgenic crops producing two or more Bacillus thuringiensis (Bt) toxins that kill the same pest. A key condition favoring durability of these "pyramided" crops is the absence of cross-resistance between toxins. Here we evaluated cross-resistance in the major lepidopteran pest Helicoverpa zea (Boddie) to Bt toxins used in pyramids. In the laboratory, we selected a strain of this pest with Bt toxin Cry1Ac followed by selection with MVP II, a formulation containing a hybrid protoxin that is identical to Cry1Ac in the active portion of the toxin and 98.5% identical overall. We calculated the resistance ratio as the EC50 (concentration causing mortality or failure to develop beyond the first instar of 50% of larvae) for the laboratory-selected strain divided by the EC50 for its field-derived parent strain that was not selected in the laboratory. The resistance ratio was 20.0-33.9 (mean=27.0) for MVP II, 57.0 for Cry1Ac, 51.3 for Cry1A.105, 22.4 for Cry1Ab, 3.3 for Cry2Ab, 1.8 for Cry1Fa, and 1.6 for Vip3Aa. Resistance ratios were 2.9 for DiPel ES and 2.0 for Agree VG, which are commercial Bt spray formulations containing Cry1Ac, other Bt toxins, and Bt spores. By the conservative criterion of non-overlap of 95% fiducial limits, the EC50 was significantly higher for the selected strain than its parent strain for MVP II, Cry1Ac, Cry1A.105, Cry1Ab, Cry2Ab and DiPel ES. For Cry1Fa, Vip3Aa, and Agree VG, significantly lower susceptibility to a high concentration indicated low cross-resistance. The resistance ratio for toxins other than Cry1Ac was associated with their amino acid sequence similarity to Cry1Ac in domain II. Resistance to Cry1Ac and the observed cross-resistance to other Bt toxins could accelerate evolution of H. zea resistance to currently registered Bt sprays and pyramided Bt crops. PMID:26458274

  20. ASSESSING POSSIBLE ECOLOGICAL RISKS OF GENETICALLY MODIFIED CROPS: GENE EXPRESSION ASSAYS AND GENETIC MONITORING OF NON-TARGET ORGANISMS

    EPA Science Inventory

    Widespread planting of genetically modified crops with the Bt transgene pesticide has led to concern over non-target effects of Bt compounds in agroecosystems. While some research suggests that non-target organisms exposed to Bt toxin exhibit reduced fecundity and increased morta...

  1. Environmental impacts of genetically modified (GM) crop use 1996-2013: Impacts on pesticide use and carbon emissions.

    PubMed

    Brookes, Graham; Barfoot, Peter

    2015-01-01

    This paper updates previous assessments of how crop biotechnology has changed the environmental impact of global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops since their first widespread commercial use in the mid 1990s. The adoption of GM insect resistant and herbicide tolerant technology has reduced pesticide spraying by 553 million kg (-8.6%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator the Environmental Impact Quotient (EIQ)) by 19.1%. The technology has also facilitated important cuts in fuel use and tillage changes, resulting in a significant reduction in the release of greenhouse gas emissions from the GM cropping area. In 2013, this was equivalent to removing 12.4 million cars from the roads. PMID:25760405

  2. Environmental impacts of genetically modified (GM) crop use 1996-2014: Impacts on pesticide use and carbon emissions.

    PubMed

    Brookes, Graham; Barfoot, Peter

    2016-04-01

    This paper updates previous assessments of important environmental impacts associated with using crop biotechnology in global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops since their first widespread commercial use in the mid 1990s. The adoption of GM insect resistant and herbicide tolerant technology has reduced pesticide spraying by 581.4 million kg (-8.2%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator, the Environmental Impact Quotient [EIQ]) by18.5%. The technology has also facilitated important cuts in fuel use and tillage changes, resulting in a significant reduction in the release of greenhouse gas emissions from the GM cropping area. In 2014, this was equivalent to removing nearly 10 million cars from the roads. PMID:27253265

  3. Molecular Breeding Strategy and Challenges Towards Improvement of Blast Disease Resistance in Rice Crop

    PubMed Central

    Ashkani, Sadegh; Rafii, Mohd Y.; Shabanimofrad, Mahmoodreza; Miah, Gous; Sahebi, Mahbod; Azizi, Parisa; Tanweer, Fatah A.; Akhtar, Mohd Sayeed; Nasehi, Abbas

    2015-01-01

    Rice is a staple and most important security food crop consumed by almost half of the world’s population. More rice production is needed due to the rapid population growth in the world. Rice blast caused by the fungus, Magnaporthe oryzae is one of the most destructive diseases of this crop in different part of the world. Breakdown of blast resistance is the major cause of yield instability in several rice growing areas. There is a need to develop strategies providing long-lasting disease resistance against a broad spectrum of pathogens, giving protection for a long time over a broad geographic area, promising for sustainable rice production in the future. So far, molecular breeding approaches involving DNA markers, such as QTL mapping, marker-aided selection, gene pyramiding, allele mining and genetic transformation have been used to develop new resistant rice cultivars. Such techniques now are used as a low-cost, high-throughput alternative to conventional methods allowing rapid introgression of disease resistance genes into susceptible varieties as well as the incorporation of multiple genes into individual lines for more durable blast resistance. The paper briefly reviewed the progress of studies on this aspect to provide the interest information for rice disease resistance breeding. This review includes examples of how advanced molecular method have been used in breeding programs for improving blast resistance. New information and knowledge gained from previous research on the recent strategy and challenges towards improvement of blast disease such as pyramiding disease resistance gene for creating new rice varieties with high resistance against multiple diseases will undoubtedly provide new insights into the rice disease control. PMID:26635817

  4. Presence of potential allergy-related linear epitopes in novel proteins from conventional crops and the implication for the safety assessment of these crops with respect to the current testing of genetically modified crops.

    PubMed

    Kleter, Gijs A; Peijnenburg, Ad A C M

    2003-09-01

    Mitochondria of cytoplasmic male sterile crop plants contain novel, chimeric open reading frames. In addition, a number of crops carry endogenous double-stranded ribonucleic acid (dsRNA). In this study, the novel proteins encoded by these genetic components were screened for the presence of potential binding sites (epitopes) of allergy-associated IgE antibodies, as was previously done with transgenic proteins from genetically modified crops. The procedure entails the identification of stretches of at least six contiguous amino acids that are shared by novel proteins and known allergenic proteins. These stretches are further checked for potential linear IgE-binding epitopes. Of the 16 novel protein sequences screened in this study, nine contained stretches of six or seven amino acids that were also present in allergenic proteins. Four cases of similarity are of special interest, given the predicted antigenicity of the identical stretch within the allergenic and novel protein, the IgE-binding by a peptide containing an identical stretch reported in literature, or the multiple incidence of identical stretches of the same allergen within a novel protein. These selected stretches are present in novel proteins derived from oilseed rape and radish (ORF138), rice (dsRNA), and fava bean (dsRNA), and warrant further clinical testing. The frequency of positive outcomes and the sizes of the identical stretches were comparable to those previously found for transgenic proteins in genetically modified crops. It is discussed whether novel proteins from conventional crops should be subject to an assessment of potential allergenicity, a procedure which is currently mandatory for transgenic proteins from genetically modified crops. PMID:17166136

  5. Assessment of the nutritional values of genetically modified wheat, corn, and tomato crops.

    PubMed

    Venneria, Eugenia; Fanasca, Simone; Monastra, Giovanni; Finotti, Enrico; Ambra, Roberto; Azzini, Elena; Durazzo, Alessandra; Foddai, Maria Stella; Maiani, Giuseppe

    2008-10-01

    The genetic modification in fruit and vegetables could lead to changes in metabolic pathways and, therefore, to the variation of the molecular pattern, with particular attention to antioxidant compounds not well-described in the literature. The aim of the present study was to compare the quality composition of transgenic wheat ( Triticum durum L.), corn ( Zea mays L.), and tomato ( Lycopersicum esculentum Mill.) to the nontransgenic control with a similar genetic background. In the first experiment, Ofanto wheat cultivar containing the tobacco rab1 gene and nontransgenic Ofanto were used. The second experiment compared two transgenic lines of corn containing Bacillus thuringiensis "Cry toxin" gene (PR33P67 and Pegaso Bt) to their nontransgenic forms. The third experiment was conducted on transgenic tomato ( Lycopersicum esculentum Mill.) containing the Agrobacterium rhizogenes rolD gene and its nontransgenic control (cv. Tondino). Conventional and genetically modified crops were compared in terms of fatty acids content, unsaponifiable fraction of antioxidants, total phenols, polyphenols, carotenoids, vitamin C, total antioxidant activity, and mineral composition. No significant differences were observed for qualitative traits analyzed in wheat and corn samples. In tomato samples, the total antioxidant activity (TAA), measured by FRAP assay, and the naringenin content showed a lower value in genetically modified organism (GMO) samples (0.35 mmol of Fe (2+) 100 g (-1) and 2.82 mg 100 g (-1), respectively), in comparison to its nontransgenic control (0.41 mmol of Fe (2+) 100 g (-1) and 4.17 mg 100 g (-1), respectively). On the basis of the principle of substantial equivalence, as articulated by the World Health Organization, the Organization for Economic Cooperation and Development, and the United Nations Food and Agriculture Organization, these data support the conclusion that GM events are nutritionally similar to conventional varieties of wheat, corn, and tomato on

  6. A look at product development with genetically modified crops: examples from maize.

    PubMed

    Mumm, Rita H

    2013-09-01

    Plant breeding for crop genetic improvement involves the cycle of creating genetic diversity and exploiting that diversity to derive an improved cultivar with outstanding performance for specific traits of interest. Genetic modification through transformation essentially expands the genepool to facilitate access to genes otherwise not available through crossing. Transgenic events are defined by the DNA sequence that has been incorporated into the target genome and the specific point(s) of insertion. In the development of a new transgenic trait, typically many events are generated and evaluated with the aim of identifying one exhibiting consistent trait expression at or above specified thresholds, stable inheritance, and the absence of any negative effects. With transgenic traits for maize, once commercial candidates have been identified, these events are introgressed into elite lines, often through the use of molecular markers that can accelerate the breeding process and aid in producing a quality conversion. Converted elite lines are yield-tested to ensure performance equivalency with their unconverted counterparts. Finally, before commercial sale of seed, quality control monitoring is conducted to ensure event identity and purity and the absence of any unintended events. This monitoring complements other quality control measures to confirm seed viability and line/hybrid purity and uniformity in seed treatments, all in an effort to ensure customer satisfaction and to comply with governmental regulations. Thus, genetically modified (GM) cultivars are subject to significant testing and auditing prior to seed sale and distribution to farmers, more testing and auditing than with non-GM cultivars. PMID:23668783

  7. Evaluation of the Doraiswamy-Thompson winter wheat crop calendar model incorporating a modified spring restart sequence

    NASA Technical Reports Server (NTRS)

    Taylor, T. W.; Ravet, F. W.; Smika, D. (Principal Investigator)

    1981-01-01

    The Robertson phenology was used to provide growth stage information to a wheat stress indicator mode. A stress indicator model demands two acurate predictions from a crop calendar: date of spring growth initiation; and crop calendar stage at growth initiation. Several approaches for restarting the Robertson phenology model at spring growth initiation were studied. Although best results were obtained with a solar thermal unit method, an alternate approach which indicates soil temperature as the controlling parameter for spring growth initiation was selected and tested. The modified model (Doraiswamy-Thompson) is compared to LACIE-Robertson model predictions.

  8. Safety assessment, detection and traceability, and societal aspects of genetically modified foods. European Network on Safety Assessment of Genetically Modified Food Crops (ENTRANSFOOD). Concluding remarks.

    PubMed

    Kuiper, H A; König, A; Kleter, G A; Hammes, W P; Knudsen, I

    2004-07-01

    The most important results from the EU-sponsored ENTRANSFOOD Thematic Network project are reviewed, including the design of a detailed step-wise procedure for the risk assessment of foods derived from genetically modified crops based on the latest scientific developments, evaluation of topical risk assessment issues, and the formulation of proposals for improved risk management and public involvement in the risk analysis process. PMID:15123387

  9. Companion cropping with potato onion enhances the disease resistance of tomato against Verticillium dahliae

    PubMed Central

    Fu, Xuepeng; Wu, Xia; Zhou, Xingang; Liu, Shouwei; Shen, Yanhui; Wu, Fengzhi

    2015-01-01

    Intercropping could alleviate soil-borne diseases, however, few studies focused on the immunity of the host plant induced by the interspecific interactions. To test whether or not intercropping could enhance the disease resistance of host plant, we investigated the effect of companion cropping with potato onion on tomato Verticillium wilt caused by Verticillium dahliae (V. dahliae). To investigate the mechanisms, the root exudates were collected from tomato and potato onion which were grown together or separately, and were used to examine the antifungal activities against V. dahliae in vitro, respectively. Furthermore, RNA-seq was used to examine the expression pattern of genes related to disease resistance in tomato companied with potato onion compared to that in tomato grown alone, under the condition of infection with V. dahliae. The results showed that companion cropping with potato onion could alleviate the incidence and severity of tomato Verticillium wilt. The further studies revealed that the root exudates from tomato companied with potato onion significantly inhibited the mycelia growth and spore germination of V. dahliae. However, there were no significant effects on these two measurements for the root exudates from potato onion grown alone or from potato onion grown with tomato. RNA-seq data analysis showed the disease defense genes associated with pathogenesis-related proteins, biosynthesis of lignin, hormone metabolism and signal transduction were expressed much higher in the tomato companied with potato onion than those in the tomato grown alone, which indicated that these defense genes play important roles in tomato against V. dahliae infection, and meant that the disease resistance of tomato against V. dahliae was enhanced in the companion copping with potato onion. We proposed that companion cropping with potato onion could enhance the disease resistance of tomato against V. dahliae by regulating the expression of genes related to disease

  10. Herbicide and cover crop residue integration for amaranth control in conservation agriculture cotton and implications for resistance management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation agriculture practices are threatened by glyphosate-resistant Palmer amaranth. Integrated practices including PRE herbicides and high-residue conservation agriculture systems may decrease Amaranth emergence. Field experiments were conducted from autumn 2006 through cash crop harvest in...

  11. Combining pest control and resistance management: synergy of engineered insects with Bt crops.

    PubMed

    Alphey, Nina; Bonsall, Michael B; Alphey, Luke

    2009-04-01

    Transgenic crops producing insecticidal toxins are widely used to control insect pests. Their benefits would be lost if resistance to the toxins became widespread in pest populations. The most widely used resistance management method is the high-dose/refuge strategy. This requires toxin-free host plants as refuges near insecticidal crops, and toxin doses intended to be sufficiently high to kill insects heterozygous for a resistant allele, thereby rendering resistance functionally recessive. We have previously shown by mathematical modeling that mass-release of harmless susceptible (toxin-sensitive) insects engineered with repressible female-specific lethality using release of insects carrying a dominant lethal ([RIDL] Oxitec Limited, United Kingdom) technology could substantially delay or reverse the spread of resistance and reduce refuge sizes. Here, we explore this proposal in depth, studying a wide range of scenarios, considering impacts on population dynamics as well as evolution of allele frequencies, comparing with releases of natural fertile susceptible insects, and examining the effect of seasonality. We investigate the outcome for pest control for which the plant-incorporated toxins are not necessarily at a high dose (i.e., they might not kill all homozygous susceptible and all heterozygous insects). We demonstrate that a RIDL-based approach could form an effective component of a resistance management strategy in a wide range of genetic and ecological circumstances. Because there are significant threshold effects for several variables, we expect that a margin of error would be advisable in setting release ratios and refuge sizes, especially as the frequency and properties of resistant alleles may be difficult to measure accurately in the field. PMID:19449654

  12. A new method for evaluating flowering synchrony to support the temporal isolation of genetically modified crops from their wild relatives.

    PubMed

    Ohigashi, Kentaro; Mizuguti, Aki; Yoshimura, Yasuyuki; Matsuo, Kazuhito; Miwa, Tetsuhisa

    2014-01-01

    Hybridization between crops and their wild relatives potentially threatens the genetic identity of the wild plants, particularly in the case of genetically modified crops. Only a few studies have examined the use of temporal isolation to prevent hybridization, and the indices used in those studies, (e.g., the days of flowering overlap), are not precise to evaluate the degree of synchrony in flowering. Here we propose a flowering similarity index that can compare the degree of flowering synchrony between two relevant species and measure the efficiency of temporal isolation. The results showed that the flowering similarity index predicts the likelihood of hybridization much better than the number of flowering-overlap days, regardless of different flowering patterns among cultivars. Thus, temporal isolation of flowering or flowering asynchrony is the most effective means in preventing hybridization between crops and their wild relatives. PMID:24122370

  13. Improving crop disease resistance: lessons from research on Arabidopsis and tomato

    PubMed Central

    Piquerez, Sophie J. M.; Harvey, Sarah E.; Beynon, Jim L.; Ntoukakis, Vardis

    2014-01-01

    One of the great challenges for food security in the 21st century is to improve yield stability through the development of disease-resistant crops. Crop research is often hindered by the lack of molecular tools, growth logistics, generation time and detailed genetic annotations, hence the power of model plant species. Our knowledge of plant immunity today has been largely shaped by the use of models, specifically through the use of mutants. We examine the importance of Arabidopsis and tomato as models in the study of plant immunity and how they help us in revealing a detailed and deep understanding of the various layers contributing to the immune system. Here we describe examples of how knowledge from models can be transferred to economically important crops resulting in new tools to enable and accelerate classical plant breeding. We will also discuss how models, and specifically transcriptomics and effectoromics approaches, have contributed to the identification of core components of the defense response which will be key to future engineering of durable and sustainable disease resistance in plants. PMID:25520730

  14. Performance and cross-crop resistance of Cry1F-maize selected Spodoptera frugiperda on transgenic Bt cotton: implications for resistance management

    PubMed Central

    Yang, Fei; Kerns, David L.; Brown, Sebe; Kurtz, Ryan; Dennehy, Tim; Braxton, Bo; Head, Graham; Huang, Fangneng

    2016-01-01

    Transgenic crops producing Bacillus thuringiensis (Bt) proteins have become a primary tool in pest management. Due to the intensive use of Bt crops, resistance of the fall armyworm, Spodoptera frugiperda, to Cry1F maize has occurred in Puerto Rico, Brazil, and some areas of the southeastern U.S. The sustainability of Bt crops faces a great challenge because the Cry1F-maize resistant S. frugiperda may also infest other Bt crops in multiple cropping ecosystems. Here we examined the survival and plant injury of a S. frugiperda population selected with Cry1F maize on three single-gene and five pyramided Bt cotton products. Larvae of Cry1F-susceptible (SS), -heterozygous (RS), and -resistant (RR) genotypes of S. frugiperda were all susceptible to the pyramided cotton containing Cry1Ac/Cry2Ab, Cry1Ac/Cry1F/Vip3A, Cry1Ab/Cry2Ae, or Cry1Ab/Cry2Ae/Vip3A, and the single-gene Cry2Ae cotton. Pyramided cotton containing Cry1Ac/Cry1F was effective against SS and RS, but not for RR. These findings show that the Cry1F-maize selected S. frugiperda can cause cross-crop resistance to other Bt crops expressing similar insecticidal proteins. Resistance management and pest management programs that utilize diversify mortality factors must be implemented to ensure the sustainability of Bt crops. This is especially important in areas where resistance to single-gene Bt crops is already widespread. PMID:27301612

  15. Performance and cross-crop resistance of Cry1F-maize selected Spodoptera frugiperda on transgenic Bt cotton: implications for resistance management.

    PubMed

    Yang, Fei; Kerns, David L; Brown, Sebe; Kurtz, Ryan; Dennehy, Tim; Braxton, Bo; Head, Graham; Huang, Fangneng

    2016-01-01

    Transgenic crops producing Bacillus thuringiensis (Bt) proteins have become a primary tool in pest management. Due to the intensive use of Bt crops, resistance of the fall armyworm, Spodoptera frugiperda, to Cry1F maize has occurred in Puerto Rico, Brazil, and some areas of the southeastern U.S. The sustainability of Bt crops faces a great challenge because the Cry1F-maize resistant S. frugiperda may also infest other Bt crops in multiple cropping ecosystems. Here we examined the survival and plant injury of a S. frugiperda population selected with Cry1F maize on three single-gene and five pyramided Bt cotton products. Larvae of Cry1F-susceptible (SS), -heterozygous (RS), and -resistant (RR) genotypes of S. frugiperda were all susceptible to the pyramided cotton containing Cry1Ac/Cry2Ab, Cry1Ac/Cry1F/Vip3A, Cry1Ab/Cry2Ae, or Cry1Ab/Cry2Ae/Vip3A, and the single-gene Cry2Ae cotton. Pyramided cotton containing Cry1Ac/Cry1F was effective against SS and RS, but not for RR. These findings show that the Cry1F-maize selected S. frugiperda can cause cross-crop resistance to other Bt crops expressing similar insecticidal proteins. Resistance management and pest management programs that utilize diversify mortality factors must be implemented to ensure the sustainability of Bt crops. This is especially important in areas where resistance to single-gene Bt crops is already widespread. PMID:27301612

  16. Environmental impact of herbicide regimes used with genetically modified herbicide-resistant maize.

    PubMed

    Devos, Yann; Cougnon, Mathias; Vergucht, Sofie; Bulcke, Robert; Haesaert, Geert; Steurbaut, Walter; Reheul, Dirk

    2008-12-01

    With the potential advent of genetically modified herbicide-resistant (GMHR) crops in the European Union, changes in patterns of herbicide use are predicted. Broad-spectrum, non-selective herbicides used with GMHR crops are expected to substitute for a set of currently used herbicides, which might alter the agro-environmental footprint from crop production. To test this hypothesis, the environmental impact of various herbicide regimes currently used with non-GMHR maize in Belgium was calculated and compared with that of possible herbicide regimes applied in GMHR maize. Impacts on human health and the environment were calculated through the pesticide occupational and environmental risk (POCER) indicator. Results showed that the environmental impact of herbicide regimes solely relying on the active ingredients glyphosate (GLY) or glufosinate-ammonium (GLU) is lower than that of herbicide regimes applied in non-GMHR maize. Due to the lower potential of GLY and GLU to contaminate ground water and their lower acute toxicity to aquatic organisms, the POCER exceedence factor values for the environment were reduced approximately by a sixth when GLY or GLU is used alone. However, the environmental impact of novel herbicide regimes tested may be underestimated due to the assumption that active ingredients used with GMHR maize would be used alone. Data retrieved from literature suggest that weed control efficacy is increased and resistance development delayed when GLY or GLU is used together with other herbicides in the GMHR system. Due to the partial instead of complete replacement of currently used herbicide regimes, the beneficial environmental impact of novel herbicide regimes might sometimes be reduced or counterbalanced. Despite the high weed control efficacy provided by the biotechnology-based weed management strategy, neither indirect harmful effects on farmland biodiversity through losses in food resources and shelter, nor shifts in weed communities have been

  17. Solutions Network Formulation Report. Using NASA Sensors to Perform Crop Type Assessment for Monitoring Insect Resistance in Corn

    NASA Technical Reports Server (NTRS)

    Lewis, David; Copenhaver, Ken; Anderson, Daniel; Hilbert, Kent

    2007-01-01

    The EPA (U.S. Environmental Protection Agency) is tasked to monitor for insect pest resistance to transgenic crops. Several models have been developed to understand the resistance properties of insects. The Population Genetics Simulator model is used in the EPA PIRDSS (Pest Infestation and Resistance Decision Support System). The EPA Office of Pesticide Programs uses the DSS to help understand the potential for insect pest resistance development and the likelihood that insect pest resistance will negatively affect transgenic corn. Once the DSS identifies areas of concern, crews are deployed to collect insect pest samples, which are tested to identify whether they have developed resistance to the toxins in transgenic corn pesticides. In this candidate solution, VIIRS (Visible/Infrared Imager/Radiometer Suite) vegetation index products will be used to build hypertemporal layerstacks for crop type and phenology assessment. The current phenology attribute is determined by using the current time of year to index the expected growth stage of the crop. VIIRS might provide more accurate crop type assessment and also might give a better estimate on the crop growth stage.

  18. Key global environmental impacts of genetically modified (GM) crop use 1996-2012.

    PubMed

    Barfoot, Peter; Brookes, Graham

    2014-01-01

    Against the background of increasing awareness and appreciation of issues such as global warming and the impact of mankind's activities such as agriculture on the global environment, this paper updates previous assessments of some key environmental impacts that crop biotechnology has had on global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops. The adoption of the technology has reduced pesticide spraying by 503 million kg (-8.8%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops (as measured by the indicator the Environmental Impact Quotient [EIQ]) by 18.7%. The technology has also facilitated a significant reduction in the release of greenhouse gas emissions from this cropping area, which, in 2012, was equivalent to removing 11.88 million cars from the roads. PMID:24637726

  19. Key environmental impacts of global genetically modified (GM) crop use 1996-2011.

    PubMed

    Brookes, Graham; Barfoot, Peter

    2013-01-01

    Given the increasing awareness and appreciation of issues such as global warming and the impact of mankind's activities such as agriculture on the global environment, this paper updates previous assessments of the environmental impact of an important and relatively new technology, crop biotechnology has had on global agriculture. It focuses on the environmental impacts associated with changes in pesticide use and greenhouse gas emissions arising from the use of GM crops. The adoption of the technology has reduced pesticide spraying by 474 million kg (-8.9%) and, as a result, decreased the environmental impact associated with herbicide and insecticide use on these crops [as measured by the indicator the Environmental Impact Quotient (EIQ)] by 18.1%. The technology has also facilitated a significant reduction in the release of greenhouse gas emissions from this cropping area, which, in 2011, was equivalent to removing 10.22 million cars from the roads. PMID:23635915

  20. Rootworm Management with Genetically Modified Corn: Current Status, Potential for Resistance, and a Look Toward the Future

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To delay evolution of insect resistance to transgenic crops producing Bacillus thuringiensis (Bt) toxins, nearby "refuges" of host plants not producing Bt toxins are required in many regions. Such refuges are expected to be most effective in slowing resistance when the toxin concentration in Bt crop...

  1. The Development of a Remote Sensor System and Decision Support Systems Architecture to Monitor Resistance Development in Transgenic Crops

    NASA Technical Reports Server (NTRS)

    Cacas, Joseph; Glaser, John; Copenhaver, Kenneth; May, George; Stephens, Karen

    2008-01-01

    The United States Environmental Protection Agency (EPA) has declared that "significant benefits accrue to growers, the public, and the environment" from the use of transgenic pesticidal crops due to reductions in pesticide usage for crop pest management. Large increases in the global use of transgenic pesticidal crops has reduced the amounts of broad spectrum pesticides used to manage pest populations, improved yield and reduced the environmental impact of crop management. A significant threat to the continued use of this technology is the evolution of resistance in insect pest populations to the insecticidal Bt toxins expressed by the plants. Management of transgenic pesticidal crops with an emphasis on conservation of Bt toxicity in field populations of insect pests is important to the future of sustainable agriculture. A vital component of this transgenic pesticidal crop management is establishing the proof of concept basic understanding, situational awareness, and monitoring and decision support system tools for more than 133650 square kilometers (33 million acres) of bio-engineered corn and cotton for development of insect resistance . Early and recent joint NASA, US EPA and ITD remote imagery flights and ground based field experiments have provided very promising research results that will potentially address future requirements for crop management capabilities.

  2. Transportability of confined field trial data from cultivation to import countries for environmental risk assessment of genetically modified crops.

    PubMed

    Nakai, Shuichi; Hoshikawa, Kana; Shimono, Ayako; Ohsawa, Ryo

    2015-12-01

    Requirement of in-country confined field trials for genetically modified (GM) crops prior to unrestricted release is well-established among countries with domestic regulations for the cultivation approval of GM crops. However, the requirement of in-country confined field trials is not common in countries where the scope of the application does not include cultivation. Nonetheless, Japan and China request in-country confined field trials for GM crops which are intended only for use as food, feed and processing. This paper considers the transportability of confined field trial data from cultivation countries (e.g. United States, Canada, and South American countries) to import countries like Japan for the environmental risk assessment of GM crops by reviewing: (1) the purpose of confined field trial assessment, (2) weediness potential, defined as "an ability to establish and persist in an unmanaged area that is frequently disturbed by human activity", of host crops, and (3) reliability of the confined field trial data obtained from cultivation countries. To review the reliability of the confined field data obtained in the US, this paper describes actual examples of three confined field trials of approved GM corn events conducted both in the US and Japan. Based on the above considerations, this paper concludes that confined field data of GM corn and cotton is transportable from cultivation countries to importing countries (e.g. from the US to Japan), regardless of the characteristics of the inserted gene(s). In addition, this paper advocates harmonization of protocols for confined field trials to facilitate more efficient data transportability across different geographies. PMID:26138875

  3. Debates on Genetically Modified Crops in the Context of Sustainable Development.

    PubMed

    Gerasimova, Ksenia

    2016-04-01

    The paper discusses conflicts in perceptions of GM crops illustrating the complexities of GM debates and applications of the concept of sustainable development. The concept consists of three discourses that both opponents and supporters of GM crops refer to in their analyses: environmentalism, social and economic development and the two sub-issues of sustainable development-biodiversity loss and food security. This creates a unique situation when both proponents and opponents of GM food use the same framework of sustainable development to support their arguments and do not reach a common ground. This will be illustrated by a review of the arguments brought by these two groups. PMID:26062746

  4. Perceptions and attitudes of Riyadh university students towards products derived from genetically modified crops in Saudi Arabia.

    PubMed

    Al-Jebreen, Dalal Hamad

    2010-01-01

    A survey was conducted during 2008 to assess the attitudes and perceptions of the Riyadh University students towards genetically modified crops and foods. Using descriptive analysis, it was found that the majority of surveyed students had good knowledge of genetic modifications, but lack knowledge about Genetically Modified Organisms (GMO) values. Most respondents would not purchase clearly labelled GMO products, though considerable number of the respondents was ready to taste or try the products. It is evident from these results that majority of university students who participated in this survey, in general had very little information or didn't know the genetic engineering technology e.g., gene therapy, fingerprinting, role in reducing pesticide application etc., as appeared in the results, therefore, most of the participants did not know or thought GM foods are harmful and could not be easily detected. The implication of this result is that majority will not support GM products. PMID:20415150

  5. Evolution of Resistance by Helicoverpa zea (Lepidoptera: Noctuidae) Infesting Insecticidal Crops in the Southern United States

    PubMed Central

    Onstad, David; Crain, Philip; Crespo, Andre; Hutchison, William; Buntin, David; Porter, Pat; Catchot, Angus; Cook, Don; Pilcher, Clint; Flexner, Lindsey; Higgins, Laura

    2016-01-01

    We created a deterministic, frequency-based model of the evolution of resistance by corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), to insecticidal traits expressed in crops planted in the heterogeneous landscapes of the southern United States. The model accounts for four generations of selection by insecticidal traits each year. We used the model results to investigate the influence of three factors on insect resistance management (IRM): 1) how does adding a third insecticidal trait to both corn and cotton affect durability of the products, 2) how does unstructured corn refuge influence IRM, and 3) how do block refuges (50% compliance) and blended refuges compare with regard to IRM? When Bt cotton expresses the same number of insecticidal traits, Bt corn with three insecticidal traits provides longer durability than Bt corn with two pyramided traits. Blended refuge provides similar durability for corn products compared with the same level of required block refuge when the rate of refuge compliance by farmers is 50%. Results for Mississippi and Texas are similar, but durabilities for corn traits are surprisingly lower in Georgia, where unstructured corn refuge is the highest of the three states, but refuge for Bt cotton is the lowest of the three states. Thus, unstructured corn refuge can be valuable for IRM but its influence is determined by selection for resistance by Bt cotton. PMID:26637533

  6. Weeds in fields with contrasting conventional and genetically modified herbicide-tolerant crops. II. Effects on individual species.

    PubMed

    Heard, M S; Hawes, C; Champion, G T; Clark, S J; Firbank, L G; Haughton, A J; Parish, A M; Perry, J N; Rothery, P; Roy, D B; Scott, R J; Skellern, M P; Squire, G R; Hill, M O

    2003-11-29

    We compared the effects of the management of genetically modified herbicide-tolerant (GMHT) and conventional beet, maize and spring oilseed rape on 12 weed species. We sampled the seedbank before and after cropping. During the season we counted plants and measured seed rain and biomass. Ratios of densities were used to calculate emergence, survival, reproduction and seedbank change. Treatments significantly affected the biomass of six species in beet, eight in maize and five in spring oilseed rape. The effects were generally consistent, with biomass lower in GMHT beet and spring oilseed rape and higher in GMHT maize. With few exceptions, emergence was higher in GMHT crops. Subsequent survival was significantly lowered for eight species in beet and six in spring oilseed rape in the GMHT treatments. It was increased for five species in maize and one in spring oilseed rape. Significant effects on seedbank change were found for four species. However, for many species in beet and spring oilseed rape (19 out of 24 cases), seed densities were lower in the seedbank after GMHT cropping. These differences compounded over time would result in large decreases in population densities of arable weeds. In maize, populations may increase. PMID:14561317

  7. Perceived Consequences of Herbicide-Tolerant and Insect-Resistant Crops on Integrated Pest Management Strategies in the Western United States: Results of an Online Survey

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conducted an online survey to assess the potential effects of herbicide-tolerant (HT) and insect-resistant (IR) crops on integrated pest management (IPM) practices in the Western United States. For HT crops, participants perceived a decrease in several IPM practices, including crop and herbicide ...

  8. Chemical control of perennial and annual weeds in herbicide resistant soybean crops.

    PubMed

    Sarpe, N; Roibu, C; Negrila, E; Bodescu, F; Fuia, S; Popa, C; Beraru, C

    2001-01-01

    In Romania, the first tests with Roundup Ready on soybean crops were performed in 1998, on 2 soil types: a) at Teleorman Station on chernozem containing 3.5% humus, 4.5% clay b) at Brăila Station placed in Danube Meadow on alluvial soil containing 3.90% humus and 46% clay. In every locality cultivated soybean cultivar S.2254 was resistant to glyphosate. During the three years of experiments (1998-2000) the crop of soybean was infested with various species of weeds (both annual and perennial) of which the most important are: Sorghum halepense (60-80%), Echinochloa crus-galli, Setaria glauca, Amaranthus retroflexus, Solarium nigrum, Yanthium italicum, Abutilon theoprasthi, Sinapis arvensis, Datum stramonium, Polygonum persicaria, Calystegia sepium, Cirsium arvense. In 3 years of experience the best weed control and the highest soybean production were obtained in the variants treated 2 times postemergent with Roundup Ready at a dose of 3 + 3 l/ha. Similar results were also obtained in the farms of the Academy of Agricultural Forestry Sciences, where GMO soybean was cultivated on 1500 hectares. PMID:12425098

  9. Resistance Evolution to Bt Crops: Predispersal Mating of European Corn Borers

    PubMed Central

    Dalecky, Ambroise; Ponsard, Sergine; Bailey, Richard I; Pélissier, Céline; Bourguet, Denis

    2006-01-01

    Over the past decade, the high-dose refuge (HDR) strategy, aimed at delaying the evolution of pest resistance to Bacillus thuringiensis (Bt) toxins produced by transgenic crops, became mandatory in the United States and is being discussed for Europe. However, precopulatory dispersal and the mating rate between resident and immigrant individuals, two features influencing the efficiency of this strategy, have seldom been quantified in pests targeted by these toxins. We combined mark-recapture and biogeochemical marking over three breeding seasons to quantify these features directly in natural populations of Ostrinia nubilalis, a major lepidopteran corn pest. At the local scale, resident females mated regardless of males having dispersed beforehand or not, as assumed in the HDR strategy. Accordingly, 0–67% of resident females mating before dispersal did so with resident males, this percentage depending on the local proportion of resident males (0% to 67.2%). However, resident males rarely mated with immigrant females (which mostly arrived mated), the fraction of females mating before dispersal was variable and sometimes substantial (4.8% to 56.8%), and there was no evidence for male premating dispersal being higher. Hence, O. nubilalis probably mates at a more restricted spatial scale than previously assumed, a feature that may decrease the efficiency of the HDR strategy under certain circumstances, depending for example on crop rotation practices. PMID:16719560

  10. On the rationale and interpretation of the Farm Scale Evaluations of genetically modified herbicide-tolerant crops.

    PubMed Central

    Squire, G R; Brooks, D R; Bohan, D A; Champion, G T; Daniels, R E; Haughton, A J; Hawes, C; Heard, M S; Hill, M O; May, M J; Osborne, J L; Perry, J N; Roy, D B; Woiwod, I P; Firbank, L G

    2003-01-01

    Farmland biodiversity and food webs were compared in conventional and genetically modified herbicide-tolerant (GMHT) crops of beet (Beta vulgaris L.), maize (Zea mays L.) and both spring and winter oilseed rape (Brassica napus L.). GMHT and conventional varieties were sown in a split-field experimental design, at 60-70 sites for each crop, spread over three starting years beginning in 2000. This paper provides a background to the study and the rationale for its design and interpretation. It shows how data on environment, field management and the biota are used to assess the current state of the ecosystem, to define the typical arable field and to devise criteria for selecting, sampling and auditing experimental sites in the Farm Scale Evaluations. The main functional and taxonomic groups in the habitat are ranked according to their likely sensitivity to GMHT cropping, and the most responsive target organisms are defined. The value of the seedbank as a baseline and as an indicator of historical trends is proposed. Evidence from experiments during the twentieth century is analysed to show that large changes in field management have affected sensitive groups in the biota by ca. 50% during a year or short run of years--a figure against which to assess any positive or negative effects of GMHT cropping. The analysis leads to a summary of factors that were, and were not, examined in the first 3 years of the study and points to where modelling can be used to extrapolate the effects to the landscape and the agricultural region. PMID:14561314

  11. Weeds in fields with contrasting conventional and genetically modified herbicide-tolerant crops. I. Effects on abundance and diversity.

    PubMed

    Heard, M S; Hawes, C; Champion, G T; Clark, S J; Firbank, L G; Haughton, A J; Parish, A M; Perry, J N; Rothery, P; Scott, R J; Skellern, M P; Squire, G R; Hill, M O

    2003-11-29

    We compared the seedbanks, seed rains, plant densities and biomasses of weeds under two contrasting systems of management in beet, maize and spring oilseed rape. Weed seedbank and plant density were measured at the same locations in two subsequent seasons. About 60 fields were sown with each crop. Each field was split, one half being sown with a conventional variety managed according to the farmer's normal practice, the other half being sown with a genetically modified herbicide-tolerant (GMHT) variety, with weeds controlled by a broad-spectrum herbicide. In beet and rape, plant densities shortly after sowing were higher in the GMHT treatment. Following weed control in conventional beet, plant densities were approximately one-fifth of those in GMHT beet. In both beet and rape, this effect was reversed after the first application of broad-spectrum herbicide, so that late-season plant densities were lower in the GMHT treatments. Biomass and seed rain in GMHT crops were between one-third and one-sixth of those in conventional treatments. The effects of differing weed-seed returns in these two crops persisted in the seedbank: densities following the GMHT treatment were about 20% lower than those following the conventional treatment. The effect of growing maize was quite different. Weed density was higher throughout the season in the GMHT treatment. Late-season biomass was 82% higher and seed rain was 87% higher than in the conventional treatment. The difference was not subsequently detectable in the seedbank because the total seed return was low after both treatments. In all three crops, weed diversity was little affected by the treatment, except for transient effects immediately following herbicide application. PMID:14561316

  12. Development of sour resistant modified 13Cr OCTG

    SciTech Connect

    Asahi, H.; Hara, T.; Kawakami, A.; Takahashi, A.

    1995-10-01

    Sour resistant 13% Cr martensitic OCTG (Oil Country Tubular Goods) with so far unexpected high CO{sub 2} corrosion resistance was developed. CO{sub 2} corrosion resistance was remarkably increased by complex additions of Cu and Ni, of which contribution to CO{sub 2} corrosion resistance corresponds to that by a further addition of 6% Cr at 180 C. SSC resistance was improved by an addition of Mo. Based on such knowledge of roles of chemical elements on corrosion properties and phase stability, 0.02%C-12.5%Cr-4.5%Ni-1.5%Mo-1.5%Cu steel was developed. This steel has good hot-workability and was produced into seamless OCTG. Corrosion rates in a high pressure CO{sub 2} environment were less than 0.1 mm/y at temperatures up to 200 C (392 F) compared with 100 C of conventional API L80-13CR. No SSC occurred in sour environments with partial pressure of 0.001MPA or less even at low pH of 3.5. At elevated temperatures no cracking and no pitting was observed in H{sub 2}S containing CO{sub 2}-brine environments. The properties of the developed steel are much better in CO{sub 2} corrosion and SSC resistance compared with those of conventional 13Cr steel and are close to those of duplex stainless steel.

  13. Modified method of aerodynamic resistance calculation and its application to potential evapotranspiration estimation

    NASA Astrophysics Data System (ADS)

    Rodný, Marek; Nolz, Reinhard; Novák, Viliam; Hlaváčiková, Hana; Loiskandl, Willibald; Himmelbauer, Margarita

    2016-04-01

    The aim of this study was to present and validate an alternative evapotranspiration calculation procedure that includes specific expression for the aerodynamic resistance. Calculated daily potential evapotranspiration totals were compared to the results of FAO56 procedure application and to the results of measurements taken with a precision weighing lysimeter permanently grown with irrigated, short grass. For the examination period from March 17 through October 31, 2011, it was found that daily potential evapotranspiration estimates obtained by both calculation procedures fitted well to the lysimeter measurements. Potential evapotranspiration daily totals calculated with the use of the proposed aerodynamic resistance calculation procedure gave better results for days with higher evapotranspiration, compared to the FAO56 method. The most important is that the approach based on the proposed alternative aerodynamic resistance could be effectively used even for a wide variety of crops, because it is not limited to any particular crop.

  14. Estimation of crop water requirements: extending the one-step approach to dual crop coefficients

    NASA Astrophysics Data System (ADS)

    Lhomme, J. P.; Boudhina, N.; Masmoudi, M. M.; Chehbouni, A.

    2015-07-01

    Crop water requirements are commonly estimated with the FAO-56 methodology based upon a two-step approach: first a reference evapotranspiration (ET0) is calculated from weather variables with the Penman-Monteith equation, then ET0 is multiplied by a tabulated crop-specific coefficient (Kc) to determine the water requirement (ETc) of a given crop under standard conditions. This method has been challenged to the benefit of a one-step approach, where crop evapotranspiration is directly calculated from a Penman-Monteith equation, its surface resistance replacing the crop coefficient. Whereas the transformation of the two-step approach into a one-step approach has been well documented when a single crop coefficient (Kc) is used, the case of dual crop coefficients (Kcb for the crop and Ke for the soil) has not been treated yet. The present paper examines this specific case. Using a full two-layer model as a reference, it is shown that the FAO-56 dual crop coefficient approach can be translated into a one-step approach based upon a modified combination equation. This equation has the basic form of the Penman-Monteith equation but its surface resistance is calculated as the parallel sum of a foliage resistance (replacing Kcb) and a soil surface resistance (replacing Ke). We also show that the foliage resistance, which depends on leaf stomatal resistance and leaf area, can be inferred from the basal crop coefficient (Kcb) in a way similar to the Matt-Shuttleworth method.

  15. Functionality of Varroa-Resistant Honey Bees (Hymenoptera: Apidae) When Used in Migratory Beekeeping for Crop Pollination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two types of honey bees, Apis mellifera L., that were bred for resistance to Varroa destructor Anderson & Trueman were evaluated for performance when used for beekeeping in an intensive, migratory crop pollination system. Colonies of these stocks (Russian honey bees [RHB] and outcrosses of bees with...

  16. Prevalence of plasmid mediated pesticide resistant bacterial assemblages in crop fields.

    PubMed

    Umamaheswari, S; Murali, M

    2010-11-01

    Three crop fields namely paddy sugarcane and tomato exposed to bavistin [Methyl (1H-benzimidazol-2-yl) carbomate], monocrotophos[Dimethyl(E)-1-methyl-2-(methyl-carbamoyl) vinyl phosphate] and kinado plus [(EZ)-2-chloro-3-dimethoxyphosphinoyloxy-X1, X1-diethylbut-2-enamide], respectively were chosen for the present investigation to know the bacterial population and degradation of pesticides. The chemical nature of the soil and water samples from the pesticide contaminated fields was analysed along with counting of the total heterotrophic bacteria (THB), Staphylococci and Enterococcci population. Mean calcium, phosphate and biological oxygen demand were maximum in tomato field water Field water recorded maximum phophate and silicate content, whereas, sugarcane field water elicited maximum dissolved oxygen content. On the other hand, available phosphate and exchangeable potassium were maximum is sugarcane field soil. Significant variations in the bacterial population were evident between the treatments in sugarcane field soil and tomato field water exposed to monocrotophos and kinado plus, respectively In addition, significant variations between THB, Staphlyococci and Enterococci population were also evinced in both the sugarcane andtomato fields. The dominant pesticide resistant bacteria, Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeuroginosa harboured plasmids and the resistant trait observed were found to be plasmid borne. PMID:21506482

  17. Identification and detection of genetically modified papaya resistant to papaya ringspot virus strains in Thailand.

    PubMed

    Nakamura, Kosuke; Kondo, Kazunari; Kobayashi, Tomoko; Noguchi, Akio; Ohmori, Kiyomi; Takabatake, Reona; Kitta, Kazumi; Akiyama, Hiroshi; Teshima, Reiko; Nishimaki-Mogami, Tomoko

    2014-01-01

    Many lines of genetically modified (GM) papaya (Carica papaya Linnaeus) have been developed worldwide to resist infection from various strains of papaya ringspot virus (PRSV). We found an unidentified and unauthorized GM papaya in imported processed papaya food. Transgenic vector construct that provides resistance to the PRSV strains isolated in Thailand was detected. An original and specific real-time polymerase chain reaction method was generated to qualitatively detect the PRSV-Thailand-resistant GM papaya. PMID:24172062

  18. Prioritizing stream types according to their potential risk to receive crop plant material--A GIS-based procedure to assist in the risk assessment of genetically modified crops and systemic insecticide residues.

    PubMed

    Bundschuh, Rebecca; Kuhn, Ulrike; Bundschuh, Mirco; Naegele, Caroline; Elsaesser, David; Schlechtriemen, Ulrich; Oehen, Bernadette; Hilbeck, Angelika; Otto, Mathias; Schulz, Ralf; Hofmann, Frieder

    2016-03-15

    Crop plant residues may enter aquatic ecosystems via wind deposition or surface runoff. In the case of genetically modified crops or crops treated with systemic pesticides, these materials may contain insecticidal Bt toxins or pesticides that potentially affect aquatic life. However, the particular exposure pattern of aquatic ecosystems (i.e., via plant material) is not properly reflected in current risk assessment schemes, which primarily focus on waterborne toxicity and not on plant material as the route of uptake. To assist in risk assessment, the present study proposes a prioritization procedure of stream types based on the freshwater network and crop-specific cultivation data using maize in Germany as a model system. To identify stream types with a high probability of receiving crop materials, we developed a formalized, criteria-based and thus transparent procedure that considers the exposure-related parameters, ecological status--an estimate of the diversity and potential vulnerability of local communities towards anthropogenic stress--and availability of uncontaminated reference sections. By applying the procedure to maize, ten stream types out of 38 are expected to be the most relevant if the ecological effects from plant-incorporated pesticides need to be evaluated. This information is an important first step to identifying habitats within these stream types with a high probability of receiving crop plant material at a more local scale, including accumulation areas. Moreover, the prioritization procedure developed in the present study may support the selection of aquatic species for ecotoxicological testing based on their probability of occurrence in stream types having a higher chance of exposure. Finally, this procedure can be adapted to any geographical region or crop of interest and is, therefore, a valuable tool for a site-specific risk assessment of crop plants carrying systemic pesticides or novel proteins, such as insecticidal Bt toxins, expressed

  19. Histone Modifications, Modifiers and Readers in Melanoma Resistance to Targeted and Immune Therapy

    PubMed Central

    Gallagher, Stuart J; Tiffen, Jessamy C; Hersey, Peter

    2015-01-01

    The treatment of melanoma has been revolutionized by new therapies targeting MAPK signaling or the immune system. Unfortunately these therapies are hindered by either primary resistance or the development of acquired resistance. Resistance mechanisms involving somatic mutations in genes associated with resistance have been identified in some cases of melanoma, however, the cause of resistance remains largely unexplained in other cases. The importance of epigenetic factors targeting histones and histone modifiers in driving the behavior of melanoma is only starting to be unraveled and provides significant opportunity to combat the problems of therapy resistance. There is also an increasing ability to target these epigenetic changes with new drugs that inhibit these modifications to either prevent or overcome resistance to both MAPK inhibitors and immunotherapy. This review focuses on changes in histones, histone reader proteins and histone positioning, which can mediate resistance to new therapeutics and that can be targeted for future therapies. PMID:26426052

  20. Novel heat-resistance UV curable waterborne polyurethane coatings modified by melamine

    NASA Astrophysics Data System (ADS)

    Fang, Z. H.; Duan, H. Y.; Zhang, Z. H.; Wang, J.; Li, D. Q.; Huang, Y. X.; Shang, J. J.; Liu, Z. Y.

    2011-03-01

    Novel UV curable waterborne polyurethane coatings (UVWPU) modified by melamine was prepared using isophorone diisocyanate (IPDI), polyethylene glycol (PEG), α,α-dimethylol propionic acid (DMPA), hydroxyethyl acrylate (HEA) as main materials. Copolymer structure was verified using Fourier transform infrared spectroscopy (FT-IR). Performance of the coatings was evaluated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), and mechanical tests such as pencil hardness and resistance to water. The results showed that the modified UVWPU film had the good thermal resistance, water resistance and mechanical properties. The optimum melamine dosage was 4.70 wt.%, the glass transition temperature ( Tg) of the modified film increased by 20.4 °C and 5% weight-loss temperature (253 °C) increased by 105 °C. No change color, crinkle, desquamate, dehisce and frothy were found after the modified film dried at 130 °C for 2 h.

  1. Compositional analysis of genetically modified (GM) crops: key issues and future needs.

    PubMed

    Hoekenga, Owen A; Srinivasan, Jannavi; Barry, Gerard; Bartholomaeus, Andrew

    2013-09-01

    Effective symposia need two strong legs to stand upon: informative presentations of recent research paired with lively discussion of these topics. Although it is easy for the organizers of a symposium to predict the usefulness of the former, as they select the speakers and their topic areas, guaranteeing productive discussion is a far more difficult task. For the Crop Composition Workshop sponsored by the International Life Sciences Institute's Committee on Food and Biotechnology (ILSI IFBIC), the organizers scheduled four roundtable discussions with preselected questions and with rapporteurs drawn from governmental organizations and public-sector research institutes (the authors). It was also the organizers' intent to let these discussions flow on the basis of the experiences of the participants and pressing issues within the overall debate on the role of crop compositional analysis within safety assessment of biotechnology as it exists now and in the future. The goal of this perspective is to summarize the issues raised, providing references when possible, and to describe the consensus statements reached through the course of these discussions. PMID:23746303

  2. Modified cellulose synthase gene from 'Arabidopsis thaliana' confers herbicide resistance to plants

    SciTech Connect

    Somerville, Chris R.; Scieble, Wolf

    2000-10-11

    Cellulose synthase ('CS'), a key enzyme in the biosynthesis of cellulose in plants is inhibited by herbicides comprising thiazolidinones such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl) phenyl-4-thiazolidinone (TZ), isoxaben and 2,6-dichlorobenzonitrile (DCB). Two mutant genes encoding isoxaben and TZ-resistant cellulose synthase have been isolated from isoxaben and TZ-resistant Arabidopsis thaliana mutants. When compared with the gene coding for isoxaben or TZ-sensitive cellulose synthase, one of the resistant CS genes contains a point mutation, wherein glycine residue 998 is replaced by an aspartic acid. The other resistant mutation is due to a threonine to isoleucine change at amino acid residue 942. The mutant CS gene can be used to impart herbicide resistance to a plant; thereby permitting the utilization of the herbicide as a single application at a concentration which ensures the complete or substantially complete killing of weeds, while leaving the transgenic crop plant essentially undamaged.

  3. Modified cellulose synthase gene from Arabidopsis thaliana confers herbicide resistance to plants

    DOEpatents

    Somerville, Chris R.; Scheible, Wolf

    2007-07-10

    Cellulose synthase ("CS"), a key enzyme in the biosynthesis of cellulose in plants is inhibited by herbicides comprising thiazolidinones such as 5-tert-butyl-carbamoyloxy-3-(3-trifluromethyl)phenyl-4-thiazolidinone (TZ), isoxaben and 2,6-dichlorobenzonitrile (DCB). Two mutant genes encoding isoxaben and TZ-resistant cellulose synthase have been isolated from isoxaben and TZ-resistant Arabidopsis thaliana mutants. When compared with the gene coding for isoxaben or TZ-sensitive cellulose synthase, one of the resistant CS genes contains a point mutation, wherein glycine residue 998 is replaced by an aspartic acid. The other resistant mutation is due to a threonine to isoleucine change at amino acid residue 942. The mutant CS gene can be used to impart herbicide resistance to a plant; thereby permitting the utilization of the herbicide as a single application at a concentration which ensures the complete or substantially complete killing of weeds, while leaving the transgenic crop plant essentially undamaged.

  4. UV resistance and dimensional stability of wood modified with isopropenyl acetate.

    PubMed

    Nagarajappa, Giridhar B; Pandey, Krishna K

    2016-02-01

    Chemical modification of Rubberwood (Hevea brasiliensis Müll.Arg) with isopropenyl acetate (IPA) in the presence of anhydrous aluminum chloride as a catalyst has been carried out under solvent free conditions. The level of modification was estimated by determining the weight percent gain and modified wood was characterized by FTIR-ATR and CP/MAS (13)C NMR spectroscopy. The effect of catalyst concentration on WPG was studied. UV resistance, moisture adsorption and dimensional stability of modified wood were evaluated. UV resistance of modified wood was evaluated by exposing unmodified and modified wood to UV irradiation in a QUV accelerated weathering tester. Unmodified wood showed rapid color changes and degradation of lignin upon exposure to UV light. Chemical modification of wood polymers with IPA was effective in reducing light induced color changes (photo-yellowing) at wood surfaces. In contrast to unmodified wood, modified wood exhibited bleaching. FTIR analysis of modified wood exposed to UV light indicated stabilization of wood polymers against UV degradation. Modified wood showed good dimensional stability and hydrophobicity. Thermogravimetric analysis showed that modification with IPA improved thermal stability of wood. Improved dimensional stability and UV resistance of modified wood indicates IPA as a promising reagent since there is no acid byproduct of reaction as observed in case of other esterification reactions. PMID:26722999

  5. Genetic basis and detection of unintended effects in genetically modified crop plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In January 2014, an international meeting sponsored by the International Life Sciences Institute/Health and Environmental Sciences Institute and the Canadian Food Inspection Agency titled “Genetic Basis of Unintended Effects in Modified Plants” was held in Ottawa, Canada, bringing together over 75 s...

  6. Advances in managing pest resistance to Bt crops: Pyramids and seed mixtures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic crops producing toxins from the soil bacterium Bacillus thuringiensis (Bt) have been widely used for the control of insect pests during the last 20 years. Although Bt crops have provided significant environmental and economic benefits, sustainable use of these crops is threatened by the r...

  7. CROP/Luc7A, a novel serine/arginine-rich nuclear protein, isolated from cisplatin-resistant cell line.

    PubMed

    Nishii, Y; Morishima, M; Kakehi, Y; Umehara, K; Kioka, N; Terano, Y; Amachi, T; Ueda, K

    2000-01-14

    A novel putative SR protein, designated cisplatin resistance-associated overexpressed protein (CROP), has been cloned from cisplatin-resistant cell lines by differential display. The N-half of the deduced amino acid sequence of 432 amino acids of CROP contains cysteine/histidine motifs and leucine zipper-like repeats. The C-half consists mostly of charged and polar amino acids: arginine (58 residues or 25%), glutamate (36 residues or 16%), serine (35 residues or 15%), lysine (30 residues, 13%), and aspartate (20 residues or 9%). The C-half is extremely hydrophilic and comprises domains rich in lysine and glutamate residues, rich in alternating arginine and glutamate residues, and rich in arginine and serine residues. The arginine/serine-rich domain is dominated by a series of 8 amino acid imperfect repetitive motif (consensus sequence, Ser-Arg-Ser-Arg-Asp/Glu-Arg-Arg-Arg), which has been found in RNA splicing factors. The RNase protection assay and Western blotting analysis indicate that the expression of CROP is about 2-3-fold higher in mRNA and protein levels in cisplatin-resistant ACHN/CDDP cells than in host ACHN cells. CROP is the human homologue of yeast Luc7p, which is supposed to be involved in 5'-splice site recognition and is essential for vegetative growth. PMID:10631324

  8. Accelerating adoption of genetically modified crops in Africa through a trade liability regime.

    PubMed

    Smyth, Stuart J; Kerr, William A; Phillips, Peter W B

    2013-06-01

    Given the apparently unbridgeable divide that has developed between the 25 odd countries that grow and trade GM crops and the evolving EU regulatory hurdles, it may be time to consider alternative strategies for realizing a global market for agricultural products. Africa is one area of the world where the battle over GM agriculture is being played out, yet it is the continent where GM could have the greatest positive impact. Numerous African nations, given their long-standing trade connections to European nations, fear that allowing the commercialization of GM crops could lead to comingling of GM and conventional products and, hence, the loss of export opportunities to the EU. These are legitimate concerns. One potential solution that warrants serious consideration would be to establish a pool of funds that could be accessed by African agricultural commodity exporters in instances where exports to Europe are rejected. A production levy could be imposed in leading industrial adopting nations (i.e., Australia, Canada and the United States). The revenue raised would provide an endowment fund that could be used to offset the costs arising from import refusals. African-sourced shipments rejected by the EU will most certainly have alternate markets, but could receive a reduced price or incur higher costs associated with serving alternate markets. The intent of the fund would be to compensate for the real difference between the net returns contracted with European importers and the final market price received. This article examines the feasibility of establishing such a fund and discusses the funding options. PMID:23601418

  9. Genetic engineering in agriculture and corporate engineering in public debate: risk, public relations, and public debate over genetically modified crops.

    PubMed

    Patel, Rajeev; Torres, Robert J; Rosset, Peter

    2005-01-01

    Corporations have long influenced environmental and occupational health in agriculture, doing a great deal of damage, making substantial profits, and shaping public debate to make it appear that environmental misfortunes are accidents of an otherwise well-functioning system, rather than systemic. The debate over the genetically modified (GM) crops is an example. The largest producer of commercial GM seeds, Monsanto, exemplifies the industry's strategies: the invocation of poor people as beneficiaries, characterization of opposition as technophobic or anti-progress, and portrayal of their products as environmentally beneficial in the absence of or despite the evidence. This strategy is endemic to contemporary market capitalism, with its incentives to companies to externalize health and environmental costs to increase profits. PMID:16350477

  10. Molecular effects of resistance elicitors from biological origin and their potential for crop protection

    PubMed Central

    Wiesel, Lea; Newton, Adrian C.; Elliott, Ian; Booty, David; Gilroy, Eleanor M.; Birch, Paul R. J.; Hein, Ingo

    2014-01-01

    Plants contain a sophisticated innate immune network to prevent pathogenic microbes from gaining access to nutrients and from colonizing internal structures. The first layer of inducible response is governed by the plant following the perception of microbe- or modified plant-derived molecules. As the perception of these molecules results in a plant response that can provide efficient resistance toward non-adapted pathogens they can also be described as “defense elicitors.” In compatible plant/microbe interactions, adapted microorganisms have means to avoid or disable this resistance response and promote virulence. However, this requires a detailed spatial and temporal response from the invading pathogens. In agricultural practice, treating plants with isolated defense elicitors in the absence of pathogens can promote plant resistance by uncoupling defense activation from the effects of pathogen virulence determinants. The plant responses to plant, bacterial, oomycete, or fungal-derived elicitors are not, in all cases, universal and need elucidating prior to the application in agriculture. This review provides an overview of currently known elicitors of biological rather than synthetic origin and places their activity into a molecular context. PMID:25484886

  11. Insulin resistance modifies the association between obesity and current asthma in adults.

    PubMed

    Cardet, Juan Carlos; Ash, Samuel; Kusa, Tope; Camargo, Carlos A; Israel, Elliot

    2016-08-01

    Insulin resistance potentiates the association between obesity and childhood asthma, but this relationship appears inconsistent in relatively small studies of adults. We investigated effect modification in adults using the National Health and Nutrition Examination Survey 2003-2012, a large, nationally representative database.Insulin resistance and a history of physician-diagnosed current asthma were obtained from 12 421 adults, ages 18-85 years. We used logistic regression to determine associations between obesity and current asthma, adjusting for age, sex, race/ethnicity, poverty income ratio and smoking status. An interaction term evaluated effect modification by insulin resistance of the obesity-asthma association.As expected, obesity was positively associated with current asthma. Insulin resistance modified this association, with obesity measured as body mass index, waist circumference or waist-to-height ratio. The relationship between obesity and current asthma was stronger with increasing insulin resistance tertiles (OR 2.05, 95% CI 2.76-3.00; p-value for interaction 0.03). This association was robust to adjustments for other components of the metabolic syndrome (hypertriglyceridaemia, hypertension, hyperglycaemia and systemic inflammation). None of these components were themselves effect modifiers of the obesity-asthma association.In this large, nationally representative sample, insulin resistance modified the association between obesity and current asthma in adults. Targeting insulin resistance may represent a novel therapeutic strategy for obese patients with asthma. PMID:27103388

  12. Thermal fatigue resistance of cobalt-modified UDIMET 700

    NASA Technical Reports Server (NTRS)

    Bizon, P. T.

    1982-01-01

    The determination of comparative thermal fatigue resistances of five cobalt composition modifications of UDIMET 700 from fluidized bed tests is described. Cobalt compositional levels of 0.1, 4.3, 8.6, 12.8, 17.0 percent were being investigated in both the bare and coated (NiCrAlY overlay) conditions. Triplicate tests of each variation including duplicate tests of three control alloys are under investigation. Fluidized beds were maintained at 550 and 1850 F for the first 5500 cycles at which time the hot bed was increased to 1922 F. Immersion time in each bed is always 3 minutes. Upon the completion of 10,000 cycles, it appears that the 8.6 percent cobalt level gives the best thermal fatigue life. Considerable deformation of the test bars was observed.

  13. Hierarchical metabolomics demonstrates substantial compositional similarity between genetically modified and conventional potato crops

    PubMed Central

    Catchpole, Gareth S.; Beckmann, Manfred; Enot, David P.; Mondhe, Madhav; Zywicki, Britta; Taylor, Janet; Hardy, Nigel; Smith, Aileen; King, Ross D.; Kell, Douglas B.; Fiehn, Oliver; Draper, John

    2005-01-01

    There is current debate whether genetically modified (GM) plants might contain unexpected, potentially undesirable changes in overall metabolite composition. However, appropriate analytical technology and acceptable metrics of compositional similarity require development. We describe a comprehensive comparison of total metabolites in field-grown GM and conventional potato tubers using a hierarchical approach initiating with rapid metabolome “fingerprinting” to guide more detailed profiling of metabolites where significant differences are suspected. Central to this strategy are data analysis procedures able to generate validated, reproducible metrics of comparison from complex metabolome data. We show that, apart from targeted changes, these GM potatoes in this study appear substantially equivalent to traditional cultivars. PMID:16186495

  14. Arabidopsis dual resistance proteins, both RPS4 and RRS1, are required for resistance to bacterial wilt in transgenic Brassica crops

    PubMed Central

    Narusaka, Mari; Hatakeyama, Katsunori; Shirasu, Ken; Narusaka, Yoshihiro

    2014-01-01

    Bacterial wilt phytopathogen Ralstonia solanacearum is a serious soil-borne disease that attacks several economically important plants worldwide, including Brassicaceae. Previous studies indicate that recognition of avirulence (Avr)-effector PopP2 by resistance (R) protein, RRS1-R, and physical interaction between RRS1-R and PopP2 in the nucleus are required for resistance. Of late, we showed that a pair of Arabidopsis thaliana TIR-NLR proteins, RRS1 and RPS4, function together in disease resistance against multiple pathogen isolates. Here, we report that dual R proteins, RRS1 and RPS4, from A. thaliana ecotype Wassilewskija confer resistance to bacterial wilt in transgenic Brassica crops. For practical applications, this finding may provide a new strategy for developing disease resistant plants that express R genes from other plants. PMID:25763492

  15. Loop-mediated isothermal amplification: rapid visual and real-time methods for detection of genetically modified crops.

    PubMed

    Randhawa, Gurinder Jit; Singh, Monika; Morisset, Dany; Sood, Payal; Zel, Jana

    2013-11-27

    A rapid, reliable, and sensitive loop-mediated isothermal amplification (LAMP) system was developed for screening of genetically modified organisms (GMOs). The optimized LAMP assays using designed primers target commonly employed promoters, i.e., Cauliflower Mosaic Virus 35S (P-35S) and Figwort Mosaic Virus promoter (P-FMV), and marker genes, i.e., aminoglycoside 3'-adenyltransferase (aadA), neomycin phosphotransferase II (nptII), and β-glucuronidase (uidA). The specificity and performance of the end-point and real-time LAMP assays were confirmed using eight genetically modified (GM) cotton events on four detection systems, employing two chemistries. LAMP assays on the isothermal real-time system were found to be most sensitive, detecting up to four target copies, within 35 min. The LAMP assays herein presented using alternate detection systems can be effectively utilized for rapid and cost-effective screening of the GM status of a sample, irrespective of the crop species or GM trait. These assays coupled with a fast and simple DNA extraction method may further facilitate on-site GMO screening. PMID:24188249

  16. Adaptation of the ToxRTool to Assess the Reliability of Toxicology Studies Conducted with Genetically Modified Crops and Implications for Future Safety Testing.

    PubMed

    Koch, Michael S; DeSesso, John M; Williams, Amy Lavin; Michalek, Suzanne; Hammond, Bruce

    2016-01-01

    To determine the reliability of food safety studies carried out in rodents with genetically modified (GM) crops, a Food Safety Study Reliability Tool (FSSRTool) was adapted from the European Centre for the Validation of Alternative Methods' (ECVAM) ToxRTool. Reliability was defined as the inherent quality of the study with regard to use of standardized testing methodology, full documentation of experimental procedures and results, and the plausibility of the findings. Codex guidelines for GM crop safety evaluations indicate toxicology studies are not needed when comparability of the GM crop to its conventional counterpart has been demonstrated. This guidance notwithstanding, animal feeding studies have routinely been conducted with GM crops, but their conclusions on safety are not always consistent. To accurately evaluate potential risks from GM crops, risk assessors need clearly interpretable results from reliable studies. The development of the FSSRTool, which provides the user with a means of assessing the reliability of a toxicology study to inform risk assessment, is discussed. Its application to the body of literature on GM crop food safety studies demonstrates that reliable studies report no toxicologically relevant differences between rodents fed GM crops or their non-GM comparators. PMID:25208336

  17. The overexpression of an Amaranthus hypochondriacus NF-YC gene modifies growth and confers water deficit stress resistance in Arabidopsis.

    PubMed

    Palmeros-Suárez, Paola A; Massange-Sánchez, Julio A; Martínez-Gallardo, Norma A; Montero-Vargas, Josaphat M; Gómez-Leyva, Juan F; Délano-Frier, John P

    2015-11-01

    Nuclear factor-Y (NF-Y), is a plant heterotrimeric transcription factor constituted by NF-YA, NF-YB and NF-YC subunits. The function of many NF-Y subunits, mostly of the A and B type, has been studied in plants, but knowledge regarding the C subunit remains fragmentary. Here, a water stress-induced NF-YC gene from Amaranthus hypochondriacus (AhNF-YC) was further characterized by its overexpression in transgenic Arabidospis thaliana plants. A role in development was inferred from modified growth rates in root, rosettes and inflorescences recorded in AhNF-YC overexpressing Arabidopsis plants, in addition to a delayed onset of flowering. Also, the overexpression of AhNF-YC caused increased seedling sensitivity to abscisic acid (ABA), and influenced the expression of several genes involved in secondary metabolism, development and ABA-related responses. An altered expression of the latter in water stressed and recovered transgenic plants, together with the observed increase in ABA sensitivity, suggested that their increased water stress resistance was partly ABA-dependent. An untargeted metabolomic analysis also revealed an altered metabolite pattern, both in normal and water stress/recovery conditions. These results suggest that AhNF-YC may play an important regulatory role in both development and stress, and represents a candidate gene for the engineering of abiotic stress resistance in commercial crops. PMID:26475185

  18. Ex-Ante Economic Impact Assessment of Genetically Modified Banana Resistant to Xanthomonas Wilt in the Great Lakes Region of Africa

    PubMed Central

    Ainembabazi, John Herbert; Tripathi, Leena; Rusike, Joseph; Abdoulaye, Tahirou; Manyong, Victor

    2015-01-01

    Background Credible empirical evidence is scanty on the social implications of genetically modified (GM) crops in Africa, especially on vegetatively propagated crops. Little is known about the future success of introducing GM technologies into staple crops such as bananas, which are widely produced and consumed in the Great Lakes Region of Africa (GLA). GM banana has a potential to control the destructive banana Xanthomonas wilt disease. Objective To gain a better understanding of future adoption and consumption of GM banana in the GLA countries which are yet to permit the production of GM crops; specifically, to evaluate the potential economic impacts of GM cultivars resistant to banana Xanthomonas wilt disease. Data Sources The paper uses data collected from farmers, traders, agricultural extension agents and key informants in the GLA. Analysis We analyze the perceptions of the respondents about the adoption and consumption of GM crop. Economic surplus model is used to determine future economic benefits and costs of producing GM banana. Results On the release of GM banana for commercialization, the expected initial adoption rate ranges from 21 to 70%, while the ceiling adoption rate is up to 100%. Investment in the development of GM banana is economically viable. However, aggregate benefits vary substantially across the target countries ranging from US$ 20 million to 953 million, highest in countries where disease incidence and production losses are high, ranging from 51 to 83% of production. Conclusion The findings support investment in the development of GM banana resistant to Xanthomonas wilt disease. The main beneficiaries of this technology development are farmers and consumers, although the latter benefit more than the former from reduced prices. Designing a participatory breeding program involving farmers and consumers signifies the successful adoption and consumption of GM banana in the target countries. PMID:26414379

  19. Successful technologies and approaches used to develop and manage resistance against crop diseases and pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food security is highly dependent on many factors including biological, climate related, and political. Soon after Mendel showed that phenotypic traits could be inherited through hybridization, scientists have been using classical genetics to increase crop production. Part of the increase in crop pr...

  20. Molecular genetics of aminoglycoside resistance genes and familial relationships of the aminoglycoside-modifying enzymes.

    PubMed Central

    Shaw, K J; Rather, P N; Hare, R S; Miller, G H

    1993-01-01

    The three classes of enzymes which inactivate aminoglycosides and lead to bacterial resistance are reviewed. DNA hybridization studies have shown that different genes can encode aminoglycoside-modifying enzymes with identical resistance profiles. Comparisons of the amino acid sequences of 49 aminoglycoside-modifying enzymes have revealed new insights into the evolution and relatedness of these proteins. A preliminary assessment of the amino acids which may be important in binding aminoglycosides was obtained from these data and from the results of mutational analysis of several of the genes encoding aminoglycoside-modifying enzymes. Recent studies have demonstrated that aminoglycoside resistance can emerge as a result of alterations in the regulation of normally quiescent cellular genes or as a result of acquiring genes which may have originated from aminoglycoside-producing organisms or from other resistant organisms. Dissemination of these genes is aided by a variety of genetic elements including integrons, transposons, and broad-host-range plasmids. As knowledge of the molecular structure of these enzymes increases, progress can be made in our understanding of how resistance to new aminoglycosides emerges. Images PMID:8385262

  1. A modified resistance equation for modeling underwater spark discharge with salinity and high pressure conditions

    SciTech Connect

    Zhao, Pengfei; Roy, Subrata

    2014-05-07

    This work investigates the performance of underwater spark discharge relating to bubble growth and decay under high pressure and with salinity conditions by introducing a modified form of the resistance equation. Here, we study salinity influence on circuit parameters by fitting the experimental data for which gap resistance is much larger in conductive water than in dielectric water. Accordingly, the resistance equation is modified by considering the influence of both plasma and its surrounding liquid. Thermal radiation effect of the bubble is also studied by comparing two different radiation models. Numerical results predict a larger bubble pressure for saline water but a reduced size and a smaller bubble cycle at a greater water depth. Such study may be useful in many saltwater applications, including that for deep sea conditions.

  2. Resistance evolution to the first generation of genetically modified Diabrotica-active Bt-maize events by western corn rootworm: management and monitoring considerations.

    PubMed

    Devos, Yann; Meihls, Lisa N; Kiss, József; Hibbard, Bruce E

    2013-04-01

    Western corn rootworm (Diabrotica virgifera virgifera; WCR) is a major coleopteran maize pest in North America and the EU, and has traditionally been managed through crop rotation and broad-spectrum soil insecticides. Genetically modified Bt-maize offers an additional management tool for WCR and has been valuable in reducing insecticide use and increasing farm income. A concern is that the widespread, repeated, and exclusive deployment of the same Bt-maize transformation event will result in the rapid evolution of resistance in WCR. This publication explores the potential of WCR to evolve resistance to plant-produced Bt-toxins from the first generation of Diabrotica-active Bt-maize events (MON 863 and MON 88017, DAS-59122-7 and MIR604), and whether currently implemented risk management strategies to delay and monitor resistance evolution are appropriate. In twelve of the twelve artificial selection experiments reported, resistant WCR populations were yielded rapidly. Field-selected resistance of WCR to Cry3Bb1 is documented in some US maize growing areas, where an increasing number of cases of unexpected damage of WCR larvae to Bt-maize MON 88017 has been reported. Currently implemented insect resistance management measures for Bt-crops usually rely on the high dose/refuge (HDR) strategy. Evidence (including laboratory, greenhouse and field data) indicates that several conditions contributing to the success of the HDR strategy may not be met for the first generation of Bt-maize events and WCR: (1) the Bt-toxins are expressed heterogeneously at a low-to-moderate dose in roots; (2) resistance alleles may be present at a higher frequency than initially assumed; (3) WCR may mate in a non-random manner; (4) resistance traits could have non-recessive inheritance; and (5) fitness costs may not necessarily be associated with resistance evolution. However, caution must be exercised when extrapolating laboratory and greenhouse results to field conditions. Model predictions

  3. Rutting and Fatigue Cracking Resistance of Waste Cooking Oil Modified Trinidad Asphaltic Materials

    PubMed Central

    Maharaj, Rean; Ramjattan-Harry, Vitra; Mohamed, Nazim

    2015-01-01

    The influence of waste cooking oil (WCO) on the performance characteristics of asphaltic materials indigenous to Trinidad, namely, Trinidad Lake Asphalt (TLA), Trinidad Petroleum Bitumen (TPB), and TLA : TPB (50 : 50) blend, was investigated to deduce the applicability of the WCO as a performance enhancer for the base asphalt. The rheological properties of complex modulus (G∗) and phase angle (δ) were measured for modified base asphalt blends containing up to 10% WCO. The results of rheology studies demonstrated that the incremental addition of WCO to the three parent binders resulted in incremental decreases in the rutting resistance (decrease in G∗/sinδ values) and increases in the fatigue cracking resistance (decrease in G∗sinδ value). The fatigue cracking resistance and rutting resistance for the TLA : TPB (50 : 50) blends were between those of the blends containing pure TLA and TPB. As operating temperature increased, an increase in the resistance to fatigue cracking and a decrease in the rutting resistance were observed for all of the WCO modified asphaltic blends. This study demonstrated the capability to create customized asphalt-WCO blends to suit special applications and highlights the potential for WCO to be used as an environmentally attractive option for improving the use of Trinidad asphaltic materials. PMID:26336652

  4. Rutting and Fatigue Cracking Resistance of Waste Cooking Oil Modified Trinidad Asphaltic Materials.

    PubMed

    Maharaj, Rean; Ramjattan-Harry, Vitra; Mohamed, Nazim

    2015-01-01

    The influence of waste cooking oil (WCO) on the performance characteristics of asphaltic materials indigenous to Trinidad, namely, Trinidad Lake Asphalt (TLA), Trinidad Petroleum Bitumen (TPB), and TLA : TPB (50 : 50) blend, was investigated to deduce the applicability of the WCO as a performance enhancer for the base asphalt. The rheological properties of complex modulus (G (∗) ) and phase angle (δ) were measured for modified base asphalt blends containing up to 10% WCO. The results of rheology studies demonstrated that the incremental addition of WCO to the three parent binders resulted in incremental decreases in the rutting resistance (decrease in G (∗) /sinδ values) and increases in the fatigue cracking resistance (decrease in G (∗) sinδ value). The fatigue cracking resistance and rutting resistance for the TLA : TPB (50 : 50) blends were between those of the blends containing pure TLA and TPB. As operating temperature increased, an increase in the resistance to fatigue cracking and a decrease in the rutting resistance were observed for all of the WCO modified asphaltic blends. This study demonstrated the capability to create customized asphalt-WCO blends to suit special applications and highlights the potential for WCO to be used as an environmentally attractive option for improving the use of Trinidad asphaltic materials. PMID:26336652

  5. Metamorphosis of cisgenic insect resistance research in the transgenic crop era

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biotechnological revolution has forever changed agricultural research and crop production worldwide. Commercial agriculture now includes plants that produce enhanced yield and quality, survival in hostile environmental conditions, manufacture and express defensive toxins, and yield grains with ...

  6. Preparation and ageing-resistant properties of polyester composites modified with functional nanoscale additives

    NASA Astrophysics Data System (ADS)

    Guo, Gang; Shi, Qiwu; Luo, Yanbing; Fan, Rangrang; Zhou, Liangxue; Qian, Zhiyong; Yu, Jie

    2014-05-01

    This study investigated ageing-resistant properties of carboxyl-terminated polyester (polyethylene glycol terephthalate) composites modified with nanoscale titanium dioxide particles (nano-TiO2). The nano-TiO2 was pretreated by a dry coating method, with aluminate coupling agent as a functional grafting additive. The agglomeration resistance was evaluated, which exhibited significant improvement for the modified nanoparticles. Then, the effects of the modified nano-TiO2 on the crosslinking and ageing-resistant properties of the composites were studied. With a real-time Fourier transform infrared (FT-IR) measurement, the nano-TiO2 displayed promoting effect on the crosslinking of polyester resin with triglycidyl isocyanurate (TGIC) as crosslinking agent. Moreover, the gloss retention, colour aberration and the surface morphologies of the composites during accelerated UV ageing (1500 hours) were investigated. The results demonstrated much less degree of ageing degradation for the nanocomposites, indicating an important role of the nano-TiO2 in improving the ageing-resistant properties of synthetic polymer composites.

  7. Preparation and ageing-resistant properties of polyester composites modified with functional nanoscale additives.

    PubMed

    Guo, Gang; Shi, Qiwu; Luo, Yanbing; Fan, Rangrang; Zhou, Liangxue; Qian, Zhiyong; Yu, Jie

    2014-01-01

    This study investigated ageing-resistant properties of carboxyl-terminated polyester (polyethylene glycol terephthalate) composites modified with nanoscale titanium dioxide particles (nano-TiO2). The nano-TiO2 was pretreated by a dry coating method, with aluminate coupling agent as a functional grafting additive. The agglomeration resistance was evaluated, which exhibited significant improvement for the modified nanoparticles. Then, the effects of the modified nano-TiO2 on the crosslinking and ageing-resistant properties of the composites were studied. With a real-time Fourier transform infrared (FT-IR) measurement, the nano-TiO2 displayed promoting effect on the crosslinking of polyester resin with triglycidyl isocyanurate (TGIC) as crosslinking agent. Moreover, the gloss retention, colour aberration and the surface morphologies of the composites during accelerated UV ageing (1500 hours) were investigated. The results demonstrated much less degree of ageing degradation for the nanocomposites, indicating an important role of the nano-TiO2 in improving the ageing-resistant properties of synthetic polymer composites. PMID:24872802

  8. Holarrhena antidysenterica Extract and Its Steroidal Alkaloid, Conessine, as Resistance-Modifying Agents Against Extensively Drug-Resistant Acinetobacter baumannii.

    PubMed

    Siriyong, Thanyaluck; Chusri, Sasitorn; Srimanote, Potjanee; Tipmanee, Varomyalin; Voravuthikunchai, Supayang Piyawan

    2016-06-01

    Emergence and spread of antibiotic-resistant Acinetobacter baumannii have become a major public health concern. This study was designed to investigate the efficacy of Holarrhena antidysenterica extract and its major steroidal alkaloid conessine as resistance-modifying agents (RMAs) on the susceptibility of A. baumannii to novobiocin and rifampicin. A significant synergistic activity of both the extract and conessine in combination with either novobiocin or rifampicin with fractional inhibitory concentration index ≤0.5 was demonstrated. Fluorescent dyes and different efflux pump inhibitors were used to further investigate the synergism. Increase in the uptake of 1-N-phenylnaphthylamine in the bacterial cells treated with the extract and conessine was not observed indicating that both substances did not act as permeabilizers. With regard to efflux pump inhibition, no accumulation in ethidium bromide (EtBr) was noticed suggesting that the AdeABC pump was not involved. In contrast, accumulation in Pyronin Y was significantly increased (p < 0.05) demonstrating that the synergism was due to interference with the AdeIJK pump. Study on frequencies of the spontaneous mutational resistance to the extract in combination with antibiotics demonstrated attenuation in drug-resistant organisms. Thus, H. antidysenterica extract and conessine as RMAs may offer a combinatory therapy to restore antibiotic susceptibility in the extensively drug-resistant A. baumannii. PMID:26745443

  9. Overexpression of a Modified Plant Thionin Enhances Disease Resistance to Citrus Canker and Huanglongbing (HLB)

    PubMed Central

    Hao, Guixia; Stover, Ed; Gupta, Goutam

    2016-01-01

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the US citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized endogenous citrus thionins and investigated their expression in different citrus tissues. Since no HLB-resistant citrus cultivars have been identified, we attempted to develop citrus resistant to both HLB and citrus canker through overexpression of a modified plant thionin. To improve effectiveness for disease resistance, we modified and synthesized the sequence encoding a plant thionin and cloned into the binary vector pBinPlus/ARS. The construct was then introduced into Agrobacterium strain EHA105 for citrus transformation. Transgenic Carrizo plants expressing the modified plant thionin were generated by Agrobacterium-mediated transformation. Successful transformation and transgene gene expression was confirmed by molecular analysis. Transgenic Carrizo plants expressing the modified thionin gene were challenged with X. citri 3213 at a range of concentrations, and a significant reduction in canker symptoms and a decrease in bacterial growth were demonstrated compared to nontransgenic plants. Furthermore, the transgenic citrus plants were challenged with HLB via graft inoculation. Our results showed significant Las titer reduction in roots of transgenic Carrizo compared with control plants and reduced scion Las titer 12 months after graft inoculation. These data provide promise for engineering citrus disease resistance against HLB and canker. PMID:27499757

  10. Overexpression of a Modified Plant Thionin Enhances Disease Resistance to Citrus Canker and Huanglongbing (HLB).

    PubMed

    Hao, Guixia; Stover, Ed; Gupta, Goutam

    2016-01-01

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the US citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an economically important disease associated with a bacterial pathogen (Xanthomonas citri). In this study, we characterized endogenous citrus thionins and investigated their expression in different citrus tissues. Since no HLB-resistant citrus cultivars have been identified, we attempted to develop citrus resistant to both HLB and citrus canker through overexpression of a modified plant thionin. To improve effectiveness for disease resistance, we modified and synthesized the sequence encoding a plant thionin and cloned into the binary vector pBinPlus/ARS. The construct was then introduced into Agrobacterium strain EHA105 for citrus transformation. Transgenic Carrizo plants expressing the modified plant thionin were generated by Agrobacterium-mediated transformation. Successful transformation and transgene gene expression was confirmed by molecular analysis. Transgenic Carrizo plants expressing the modified thionin gene were challenged with X. citri 3213 at a range of concentrations, and a significant reduction in canker symptoms and a decrease in bacterial growth were demonstrated compared to nontransgenic plants. Furthermore, the transgenic citrus plants were challenged with HLB via graft inoculation. Our results showed significant Las titer reduction in roots of transgenic Carrizo compared with control plants and reduced scion Las titer 12 months after graft inoculation. These data provide promise for engineering citrus disease resistance against HLB and canker. PMID:27499757

  11. Efficacy of Genetically Modified Bt Toxins Alone and in Combinations Against Pink Bollworm Resistant to Cry1Ac and Cry2Ab

    PubMed Central

    Tabashnik, Bruce E.; Fabrick, Jeffrey A.; Unnithan, Gopalan C.; Yelich, Alex J.; Masson, Luke; Zhang, Jie; Bravo, Alejandra; Soberón, Mario

    2013-01-01

    Evolution of resistance in pests threatens the long-term efficacy of insecticidal proteins from Bacillus thuringiensis (Bt) used in sprays and transgenic crops. Previous work showed that genetically modified Bt toxins Cry1AbMod and Cry1AcMod effectively countered resistance to native Bt toxins Cry1Ab and Cry1Ac in some pests, including pink bollworm (Pectinophora gossypiella). Here we report that Cry1AbMod and Cry1AcMod were also effective against a laboratory-selected strain of pink bollworm resistant to Cry2Ab as well as to Cry1Ab and Cry1Ac. Resistance ratios based on the concentration of toxin killing 50% of larvae for the resistant strain relative to a susceptible strain were 210 for Cry2Ab, 270 for Cry1Ab, and 310 for Cry1Ac, but only 1.6 for Cry1AbMod and 2.1 for Cry1AcMod. To evaluate the interactions among toxins, we tested combinations of Cry1AbMod, Cry1Ac, and Cry2Ab. For both the resistant and susceptible strains, the net results across all concentrations tested showed slight but significant synergism between Cry1AbMod and Cry2Ab, whereas the other combinations of toxins did not show consistent synergism or antagonism. The results suggest that the modified toxins might be useful for controlling populations of pink bollworm resistant to Cry1Ac, Cry2Ab, or both. PMID:24244692

  12. Binding and Oligomerization of Modified and Native Bt Toxins in Resistant and Susceptible Pink Bollworm

    PubMed Central

    Ocelotl, Josue; Sánchez, Jorge; Arroyo, Raquel; García-Gómez, Blanca I.; Gómez, Isabel; Unnithan, Gopalan C.; Tabashnik, Bruce E.; Bravo, Alejandra; Soberón, Mario

    2015-01-01

    Insecticidal proteins from Bacillus thuringiensis (Bt) are used extensively in sprays and transgenic crops for pest control, but their efficacy is reduced when pests evolve resistance. Better understanding of the mode of action of Bt toxins and the mechanisms of insect resistance is needed to enhance the durability of these important alternatives to conventional insecticides. Mode of action models agree that binding of Bt toxins to midgut proteins such as cadherin is essential for toxicity, but some details remain unresolved, such as the role of toxin oligomers. In this study, we evaluated how Bt toxin Cry1Ac and its genetically engineered counterpart Cry1AcMod interact with brush border membrane vesicles (BBMV) from resistant and susceptible larvae of Pectinophora gossypiella (pink bollworm), a global pest of cotton. Compared with Cry1Ac, Cry1AcMod lacks 56 amino acids at the amino-terminus including helix α-1; previous work showed that Cry1AcMod formed oligomers in vitro without cadherin and killed P. gossypiella larvae harboring cadherin mutations linked with >1000-fold resistance to Cry1Ac. Here we found that resistance to Cry1Ac was associated with reduced oligomer formation and insertion. In contrast, Cry1AcMod formed oligomers in BBMV from resistant larvae. These results confirm the role of cadherin in oligomerization of Cry1Ac in susceptible larvae and imply that forming oligomers without cadherin promotes toxicity of Cry1AcMod against resistant P. gossypiella larvae that have cadherin mutations. PMID:26633693

  13. Interface-modified random circuit breaker network model applicable to both bipolar and unipolar resistance switching

    NASA Astrophysics Data System (ADS)

    Lee, S. B.; Lee, J. S.; Chang, S. H.; Yoo, H. K.; Kang, B. S.; Kahng, B.; Lee, M.-J.; Kim, C. J.; Noh, T. W.

    2011-01-01

    We observed reversible-type changes between bipolar (BRS) and unipolar resistance switching (URS) in one Pt/SrTiOx/Pt capacitor. To explain both BRS and URS in a unified scheme, we introduce the "interface-modified random circuit breaker network model," in which the bulk medium is represented by a percolating network of circuit breakers. To consider interface effects in BRS, we introduce circuit breakers to investigate resistance states near the interface. This percolation model explains the reversible-type changes in terms of connectivity changes in the circuit breakers and provides insights into many experimental observations of BRS which are under debate by earlier theoretical models.

  14. In Vitro Antibacterial and Antibiotic Resistance Modifying Effect of Bioactive Plant Extracts on Methicillin-Resistant Staphylococcus epidermidis

    PubMed Central

    Chovanová, Romana; Vaverková, Štefánia

    2013-01-01

    The crude extracts of plants from Asteraceae and Lamiaceae family and essential oils from Salvia officinalis and Salvia sclarea were studied for their antibacterial as well as antibiotic resistance modifying activity. Using disc diffusion and broth microdilution assays we determined higher antibacterial effect of three Salvia spp. and by evaluating the leakage of 260 nm absorbing material we detected effect of extracts and, namely, of essential oils on the disruption of cytoplasmic membrane. The evaluation of in vitro interactions between plant extracts and oxacillin described in terms of fractional inhibitory concentration (FIC) indices revealed synergistic or additive effects of plant extracts and clearly synergistic effects of essential oil from Salvia officinalis with oxacillin in methicillin-resistant Staphylococcus epidermidis. PMID:24222768

  15. Invertebrate responses to the management of genetically modified herbicide-tolerant and conventional spring crops. II. Within-field epigeal and aerial arthropods.

    PubMed Central

    Haughton, A J; Champion, G T; Hawes, C; Heard, M S; Brooks, D R; Bohan, D A; Clark, S J; Dewar, A M; Firbank, L G; Osborne, J L; Perry, J N; Rothery, P; Roy, D B; Scott, R J; Woiwod, I P; Birchall, C; Skellern, M P; Walker, J H; Baker, P; Browne, E L; Dewar, A J G; Garner, B H; Haylock, L A; Horne, S L; Mason, N S; Sands, R J N; Walker, M J

    2003-01-01

    The effects of the management of genetically modified herbicide-tolerant (GMHT) crops on the abundances of aerial and epigeal arthropods were assessed in 66 beet, 68 maize and 67 spring oilseed rape sites as part of the Farm Scale Evaluations of GMHT crops. Most higher taxa were insensitive to differences between GMHT and conventional weed management, but significant effects were found on the abundance of at least one group within each taxon studied. Numbers of butterflies in beet and spring oilseed rape and of Heteroptera and bees in beet were smaller under the relevant GMHT crop management, whereas the abundance of Collembola was consistently greater in all GMHT crops. Generally, these effects were specific to each crop type, reflected the phenology and ecology of the arthropod taxa, were indirect and related to herbicide management. These results apply generally to agriculture across Britain, and could be used in mathematical models to predict the possible long-term effects of the widespread adoption of GMHT technology. The results for bees and butterflies relate to foraging preferences and might or might not translate into effects on population densities, depending on whether adoption leads to forage reductions over large areas. These species, and the detritivore Collembola, may be useful indicator species for future studies of GMHT management. PMID:14561319

  16. Invertebrate responses to the management of genetically modified herbicide-tolerant and conventional spring crops. II. Within-field epigeal and aerial arthropods.

    PubMed

    Haughton, A J; Champion, G T; Hawes, C; Heard, M S; Brooks, D R; Bohan, D A; Clark, S J; Dewar, A M; Firbank, L G; Osborne, J L; Perry, J N; Rothery, P; Roy, D B; Scott, R J; Woiwod, I P; Birchall, C; Skellern, M P; Walker, J H; Baker, P; Browne, E L; Dewar, A J G; Garner, B H; Haylock, L A; Horne, S L; Mason, N S; Sands, R J N; Walker, M J

    2003-11-29

    The effects of the management of genetically modified herbicide-tolerant (GMHT) crops on the abundances of aerial and epigeal arthropods were assessed in 66 beet, 68 maize and 67 spring oilseed rape sites as part of the Farm Scale Evaluations of GMHT crops. Most higher taxa were insensitive to differences between GMHT and conventional weed management, but significant effects were found on the abundance of at least one group within each taxon studied. Numbers of butterflies in beet and spring oilseed rape and of Heteroptera and bees in beet were smaller under the relevant GMHT crop management, whereas the abundance of Collembola was consistently greater in all GMHT crops. Generally, these effects were specific to each crop type, reflected the phenology and ecology of the arthropod taxa, were indirect and related to herbicide management. These results apply generally to agriculture across Britain, and could be used in mathematical models to predict the possible long-term effects of the widespread adoption of GMHT technology. The results for bees and butterflies relate to foraging preferences and might or might not translate into effects on population densities, depending on whether adoption leads to forage reductions over large areas. These species, and the detritivore Collembola, may be useful indicator species for future studies of GMHT management. PMID:14561319

  17. Model-based tolerance intervals derived from cumulative historical composition data: application for substantial equivalence assessment of a genetically modified crop.

    PubMed

    Hong, Bonnie; Fisher, Tracey L; Sult, Theresa S; Maxwell, Carl A; Mickelson, James A; Kishino, Hirohisa; Locke, Mary E H

    2014-10-01

    Compositional analysis is a requisite component of the substantial equivalence framework utilized to assess genetically modified (GM) crop safety. Statistical differences in composition data between GM and non-GM crops require a context in which to determine biological relevance. This context is provided by surveying the natural variation of key nutrient and antinutrient levels within the crop population with a history of safe use. Data accumulated from various genotypes with a history of safe use cultivated in relevant commercial crop-growing environments over multiple seasons are discussed as the appropriate data representative of this natural variation. A model-based parametric tolerance interval approach, which accounts for the correlated and unbalanced data structure of cumulative historical data collected from multisite field studies conducted over multiple seasons, is presented. This paper promotes the application of this tolerance interval approach to generate reference ranges for evaluation of the biological relevance of statistical differences identified during substantial equivalence assessment of a GM crop. PMID:25208038

  18. An Individual-Based Model of the Evolution of Pesticide Resistance in Heterogeneous Environments: Control of Meligethes aeneus Population in Oilseed Rape Crops

    PubMed Central

    Stratonovitch, Pierre; Elias, Jan; Denholm, Ian; Slater, Russell; Semenov, Mikhail A.

    2014-01-01

    Preventing a pest population from damaging an agricultural crop and, at the same time, preventing the development of pesticide resistance is a major challenge in crop protection. Understanding how farming practices and environmental factors interact with pest characteristics to influence the spread of resistance is a difficult and complex task. It is extremely challenging to investigate such interactions experimentally at realistic spatial and temporal scales. Mathematical modelling and computer simulation have, therefore, been used to analyse resistance evolution and to evaluate potential resistance management tactics. Of the many modelling approaches available, individual-based modelling of a pest population offers most flexibility to include and analyse numerous factors and their interactions. Here, a pollen beetle (Meligethes aeneus) population was modelled as an aggregate of individual insects inhabiting a spatially heterogeneous landscape. The development of the pest and host crop (oilseed rape) was driven by climatic variables. The agricultural land of the landscape was managed by farmers applying a specific rotation and crop protection strategy. The evolution of a single resistance allele to the pyrethroid lambda cyhalothrin was analysed for different combinations of crop management practices and for a recessive, intermediate and dominant resistance allele. While the spread of a recessive resistance allele was severely constrained, intermediate or dominant resistance alleles showed a similar response to the management regime imposed. Calendar treatments applied irrespective of pest density accelerated the development of resistance compared to ones applied in response to prescribed pest density thresholds. A greater proportion of spring-sown oilseed rape was also found to increase the speed of resistance as it increased the period of insecticide exposure. Our study demonstrates the flexibility and power of an individual-based model to simulate how farming

  19. Comparative environmental impact assessment of herbicides used on genetically modified and non-genetically modified herbicide-tolerant canola crops using two risk indicators.

    PubMed

    Oliver, Danielle P; Kookana, Rai S; Miller, Rosalind B; Correll, Raymond L

    2016-07-01

    Canola (Brassica napus L.) is the third largest field crop in Australia by area sown. Genetically modified (GM) and non-GM canola varieties released or being developed in Australia include Clearfield® (imidazolinone tolerant), TT (triazine tolerant), InVigor® (glufosinate-ammonium tolerant), Roundup Ready® - RR® (glyphosate tolerant) and Hyola® RT® (tolerant to both glyphosate and triazine). We used two risk assessment approaches - the Environmental Impact Quotient (EIQ) and the Pesticide Impact Rating Index (PIRI) - to compare the environmental risks associated with herbicides used in the canola varieties (GM and non-GM) that are currently grown or may be grown in the future. Risk assessments found that from an environmental impact viewpoint a number of herbicides used in the production of TT canola showed high relative risk in terms of mobility and ecotoxicity of herbicides. The EIQ field use rating values for atrazine and simazine in particular were high compared with those for glyphosate and trifluralin. Imazapic and imazapyr, which are only used in Clearfield® canola, had extremely low EIQ field use rating values, likely reflecting the very low application rates used for these chemicals (0.02 to 0.04kg/ha) compared with those used for atrazine and simazine (1.2 to 1.5kg/ha). The PIRI assessment showed that irrespective of the canola variety grown, trifluralin posed a high toxicity risk to fish (Rainbow trout, Oncorhynchus mykiss), algae and Daphnia sp. While the replacement of trifluralin with propyzamide had little effect on the mobility score, it greatly decreased the ecotoxicity score to fish, algae and Daphnia sp. due to the lower LC50 values for propyzamide compared with trifluralin. This study has shown that based on likelihood of off-site transport of herbicides in surface water and potential toxicity to non-target organisms, the GM canola varieties have no advantage over non-herbicide tolerant (non HT) or Clearfield® canola. PMID:27039064

  20. Zingiber officinale (ginger) compounds have tetracycline-resistance modifying effects against clinical extensively drug-resistant Acinetobacter baumannii.

    PubMed

    Wang, Hui-Min; Chen, Chung-Yi; Chen, Hsi-An; Huang, Wan-Chun; Lin, Wei-Ru; Chen, Tun-Chieh; Lin, Chun-Yu; Chien, Hsin-Ju; Lu, Po-Liang; Lin, Chiu-Mei; Chen, Yen-Hsu

    2010-12-01

    Extensively drug-resistant Acinetobacter baumannii (XDRAB) is a growing and serious nosocomial infection worldwide, such that developing new agents against it is critical. The antimicrobial activities of the rhizomes from Zingiber officinale, known as ginger, have not been proven in clinical bacterial isolates with extensive drug-resistance. This study aimed to investigate the effects of four known components of ginger, [6]-dehydrogingerdione, [10]-gingerol, [6]-shogaol and [6]-gingerol, against clinical XDRAB. All these compounds showed antibacterial effects against XDRAB. Combined with tetracycline, they showed good resistance modifying effects to modulate tetracycline resistance. Using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging method, these four ginger compounds demonstrated antioxidant properties, which were inhibited by MnO₂, an oxidant without antibacterial effects. After the antioxidant property was blocked, their antimicrobial effects were abolished significantly. These results indicate that ginger compounds have antioxidant effects that partially contribute to their antimicrobial activity and are candidates for use in the treatment of infections with XDRAB. PMID:20564496

  1. Cross-resistance to UV radiation of a cisplatin-resistant human cell line: Overexpression of cellular factors that recognize UV-modified DNA

    SciTech Connect

    Chao, C.C.; Huang, S.L.; Huang, H.M.; Lin-Chao, S. )

    1991-04-01

    A human cell line selected for cisplatin resistance (CPR) was irradiated with UV light and showed cross-resistance to UV light. Applying a modified chloramphenicol acetyltransferase assay, we observed that CPR cells acquired enhanced host cell reactivation of a transfected plasmid carrying UV damage. Gel mobility shift analysis indicated that two nuclear factors that recognize UV-modified DNA were overexpressed in CPR cells. In addition, factors that bind UV-modified DNA were independent from the factors that bind cisplatin-modified DNA. The significance of the identified binding factors, possibly DNA repair enzymes, is discussed.

  2. Calibration and validation of a modified steady-state model of crop response to saline water irrigation under conditions of transient root zone salinity

    NASA Astrophysics Data System (ADS)

    Vinten, A. J. A.; Frenkel, H.; Shalhevet, J.; Elston, D. A.

    1991-01-01

    In many situations where annual crops are irrigated with saline water, root zone salinity does not reach a steady state. Use of a steady-state description of root zone salinity may then seriously overestimate the calculated leaching requirements of the crop. A steady-state semi-emphirical model of crop response to irrigation with saline water has been calibrated using data from a number of field experiments. Predictions of yield deficit resulting from irrigation with saline water have been made for each of these experiments, using both the original model and a modified version which allows for the non-steady-state salinity conditions occurring in the experiments. Comparison with experimental data shows a clear superiority of the modified version in most cases studied. Where the original model is superior or equally good, it is likely that steady-state conditions are being approached. Where root zone salinity data were available and applicable, the modified model predicted root zone salinity much better. Approaches for distinguishing errors in calibration from intrinsic errors in the model assumptions are discussed.

  3. The use of whole food animal studies in the safety assessment of genetically modified crops: Limitations and recommendations

    PubMed Central

    Bartholomaeus, Andrew; Parrott, Wayne; Bondy, Genevieve

    2013-01-01

    There is disagreement internationally across major regulatory jurisdictions on the relevance and utility of whole food (WF) toxicity studies on GM crops, with no harmonization of data or regulatory requirements. The scientific value, and therefore animal ethics, of WF studies on GM crops is a matter addressable from the wealth of data available on commercialized GM crops and WF studies on irradiated foods. We reviewed available GM crop WF studies and considered the extent to which they add to the information from agronomic and compositional analyses. No WF toxicity study was identified that convincingly demonstrated toxicological concern or that called into question the adequacy, sufficiency, and reliability of safety assessments based on crop molecular characterization, transgene source, agronomic characteristics, and/or compositional analysis of the GM crop and its near-isogenic line. Predictions of safety based on crop genetics and compositional analyses have provided complete concordance with the results of well-conducted animal testing. However, this concordance is primarily due to the improbability of de novo generation of toxic substances in crop plants using genetic engineering practices and due to the weakness of WF toxicity studies in general. Thus, based on the comparative robustness and reliability of compositional and agronomic considerations and on the absence of any scientific basis for a significant potential for de novo generation of toxicologically significant compositional alterations as a sole result of transgene insertion, the conclusion of this review is that WF animal toxicity studies are unnecessary and scientifically unjustifiable. PMID:24164514

  4. The use of whole food animal studies in the safety assessment of genetically modified crops: limitations and recommendations.

    PubMed

    Bartholomaeus, Andrew; Parrott, Wayne; Bondy, Genevieve; Walker, Kate

    2013-11-01

    There is disagreement internationally across major regulatory jurisdictions on the relevance and utility of whole food (WF) toxicity studies on GM crops, with no harmonization of data or regulatory requirements. The scientific value, and therefore animal ethics, of WF studies on GM crops is a matter addressable from the wealth of data available on commercialized GM crops and WF studies on irradiated foods. We reviewed available GM crop WF studies and considered the extent to which they add to the information from agronomic and compositional analyses. No WF toxicity study was identified that convincingly demonstrated toxicological concern or that called into question the adequacy, sufficiency, and reliability of safety assessments based on crop molecular characterization, transgene source, agronomic characteristics, and/or compositional analysis of the GM crop and its near-isogenic line. Predictions of safety based on crop genetics and compositional analyses have provided complete concordance with the results of well-conducted animal testing. However, this concordance is primarily due to the improbability of de novo generation of toxic substances in crop plants using genetic engineering practices and due to the weakness of WF toxicity studies in general. Thus, based on the comparative robustness and reliability of compositional and agronomic considerations and on the absence of any scientific basis for a significant potential for de novo generation of toxicologically significant compositional alterations as a sole result of transgene insertion, the conclusion of this review is that WF animal toxicity studies are unnecessary and scientifically unjustifiable. PMID:24164514

  5. Captures of MFO-resistant Cydia pomonella adults as affected by lure, crop management system and flight.

    PubMed

    Bosch, D; Rodríguez, M A; Avilla, J

    2016-02-01

    The main resistance mechanism of codling moth (Cydia pomonella) in the tree fruit area of Lleida (NE Spain) is multifunction oxidases (MFO). We studied the frequency of MFO-resistant adults captured by different lures, with and without pear ester, and flights in orchards under different crop management systems. The factor year affected codling moth MFO-resistance level, particularly in the untreated orchards, highlighting the great influence of codling moth migration on the spread of resistance in field populations. Chemical treatments and adult flight were also very important but mating disruption technique showed no influence. The second adult flight showed the highest frequency, followed by the first flight and the third flight. In untreated orchards, there were no significant differences in the frequency of MFO-resistant individuals attracted by Combo and BioLure. Red septa lures baited with pear ester (DA) captured sufficient insects only in the first generation of 2010, obtaining a significantly lower proportion of MFO-resistant adults than Combo and BioLure. In the chemically treated orchards, in 2009 BioLure caught a significantly lower proportion of MFO-resistant adults than Combo during the first and third flight, and also than DA during the first flight. No significant differences were found between the lures or flights in 2010. These results cannot support the idea of a higher attractiveness of the pear ester for MFO-resistant adults in the field but do suggest a high influence of the response to the attractant depending on the management of the orchard, particularly with regard to the use of chemical insecticides. PMID:26497943

  6. Modified two-fluid model of conductivity for superconducting surface resistance calculation. Master's thesis

    SciTech Connect

    Linden, D.S.

    1993-05-01

    The traditional two-fluid model of superconducting conductivity was modified to make it accurate, while remaining fast, for designing and simulating microwave devices. The modification reflects the BCS coherence effects in the conductivity of a superconductor, and is incorporated through the ratio of normal to superconducting electrons. This modified ratio is a simple analytical expression which depends on frequency, temperature and material parameters. This modified two-fluid model allows accurate and rapid calculation of the microwave surface impedance of a superconductor in the clean and dirty limits and in the weak- and strong-coupled regimes. The model compares well with surface resistance data for Nb and provides insight into Nb3Sn and Y1Ba2Cu3O(7-delta). Numerical calculations with the modified two-fluid model are an order of magnitude faster than the quasi-classical program by Zimmermann (1), and two to five orders of magnitude faster than Halbritter's BCS program (2) for surface resistance.

  7. Thai ethnomedicinal plants as resistant modifying agents for combating Acinetobacter baumannii infections

    PubMed Central

    2012-01-01

    Abstracts Background Acinetobacter baumannii is well-recognized as an important nosocomial pathogen, however, due to their intrinsic resistance to several antibiotics, treatment options are limited. Synergistic effects between antibiotics and medicinal plants, particularly their active components, have intensively been studied as alternative approaches. Methods Fifty-one ethanol extracts obtained from 44 different selected medicinal plant species were tested for resistance modifying agents (RMAs) of novobiocin against A. baumannii using growth inhibition assay. Results At 250 μg/ml, Holarrhena antidysenterica, Punica granatum, Quisqualis indica, Terminalia bellirica, Terminalia chebula, and Terminalia sp. that possessed low intrinsic antibacterial activity significantly enhanced the activity of novobiocin at 1 μg/ml (1/8xminimum inhibitory concentration) against this pathogen. Holarrhena antidysenterica at 7.8 μg/ml demonstrated remarkable resistant modifying ability against A. baumannii in combination with novobiocin. The phytochemical study revealed that constituents of this medicinal plant contain alkaloids, condensed tannins, and triterpenoids. Conclusion The use of Holarrhena antidysenterica in combination with novobiocin provides an effective alternative treatment for multidrug resistant A. baumannii infections. PMID:22536985

  8. Understanding mechanisms of host resistance against greenbug in cereal crops - an interdisciplinary, collaborative approach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At Texas AgriLife Research - Amarillo, we have an ongoing research program focusing on elucidating the mechanisms of interactions between the phloem-feeding aphid pests and cereal crop hosts using the wheat-greenbug as a model system. During this workshop, recent results from our research on the fo...

  9. Using biotechnology to improve resistance to environmental stress in fruit crops: The importance of understanding physiology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Environmental stress can significantly impact the yield, fruit quality, and longevity of fruit trees. In particular, freeze injury can result in the loss of an entire crop or even an entire orchard. Over the past two decades, significant advances have been made in understanding the genetic regulat...

  10. Effect of soil biochar amendment on grain crop resistance to Fusarium mycotoxin contamination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mycotoxin contamination of food and feed is among the top food safety concerns. Fusarium spp. cause serious diseases in cereal crops reducing yield and contaminating grain with mycotoxins that can be deleterious to human and animal health. Fusarium graminearum and Fusarium verticillioides infect whe...

  11. Changes in the Chemical Composition and Decay Resistance of Thermally-Modified Hevea brasiliensis Wood.

    PubMed

    Severo, Elias Taylor Durgante; Calonego, Fred Willians; Sansígolo, Cláudio Angeli; Bond, Brian

    2016-01-01

    In this study the effect of thermal treatment on the equilibrium moisture content, chemical composition and biological resistance to decay fungi of juvenile and mature Hevea brasiliensis wood (rubber wood) was evaluated. Samples were taken from a 53-year-old rubber wood plantation located in Tabapuã, Sao Paulo, Brazil. The samples were thermally-modified at 180°C, 200°C and 220°C. Results indicate that the thermal modification caused: (1) a significant increase in the extractive content and proportional increase in the lignin content at 220°C; (2) a significant decrease in the equilibrium moisture content, holocelluloses, arabinose, galactose and xylose content, but no change in glucose content; and (3) a significant increase in wood decay resistance against both Pycnoporus sanguineus (L.) Murrill and Gloeophyllum trabeum (Pers.) Murrill decay fungi. The greatest decay resistance was achieved from treatment at 220°C which resulted in a change in wood decay resistance class from moderately resistant to resistant. Finally, this study also demonstrated that the influence of thermal treatment in mature wood was lower than in juvenile wood. PMID:26986200

  12. Changes in the Chemical Composition and Decay Resistance of Thermally-Modified Hevea brasiliensis Wood

    PubMed Central

    2016-01-01

    In this study the effect of thermal treatment on the equilibrium moisture content, chemical composition and biological resistance to decay fungi of juvenile and mature Hevea brasiliensis wood (rubber wood) was evaluated. Samples were taken from a 53-year-old rubber wood plantation located in Tabapuã, Sao Paulo, Brazil. The samples were thermally-modified at 180°C, 200°C and 220°C. Results indicate that the thermal modification caused: (1) a significant increase in the extractive content and proportional increase in the lignin content at 220°C; (2) a significant decrease in the equilibrium moisture content, holocelluloses, arabinose, galactose and xylose content, but no change in glucose content; and (3) a significant increase in wood decay resistance against both Pycnoporus sanguineus (L.) Murrill and Gloeophyllum trabeum (Pers.) Murrill decay fungi. The greatest decay resistance was achieved from treatment at 220°C which resulted in a change in wood decay resistance class from moderately resistant to resistant. Finally, this study also demonstrated that the influence of thermal treatment in mature wood was lower than in juvenile wood. PMID:26986200

  13. Modified ferritic iron alloys with improved high-temperature mechanical properties and oxidation resistance

    NASA Technical Reports Server (NTRS)

    Oldrieve, R. E.

    1975-01-01

    An alloy modification program was conducted in which the compositions of two existing Fe-Cr-Al alloys (Armco 18SR and GE-1541) were changed to achieve either improved high-temperature strength or improved fabricability. Only modifications of Armco 18SR were successful in achieving increased strength without loss of fabricability or oxidation resistance. The best modified alloy, designated NASA-18T, had twice the rupture strength of Armco 18SR at 800 and 1000 C. The NASA-18T alloy also had better oxidation resistance than Armco 18SR and comparable fabricability. The nominal composition of NASA-18T is Fe-18Cr-2Al-1Si-1.25Ta. All attempted modifications of the GE-1541 alloy were unsuccessful in terms of achieving better fabricability without sacrificing high-temperature strength and oxidation resistance.

  14. Hypothesis: SLC12A3 Polymorphism modifies thiazide hypersensitivity of antenatal Bartter syndrome to thiazide resistance.

    PubMed

    Mammen, Cherry; Rupps, Rosemarie; Trnka, Peter; Boerkoel, Cornelius F

    2012-02-01

    We report a 5-year-old boy with thiazide-resistant Bartter syndrome. This is highly unusual since thiazide hypersensitivity is a common diagnostic finding in Bartter syndrome patients. Subsequent molecular testing identified compound heterozygosity for two novel mutations in KCNJ1, (c.556A > G and c.683G > A) which is associated with Bartter syndrome, and a paternally inherited polymorphism in SLC12A3 (c.791G > C). Mutations in SLC12A3 cause the thiazide-resistant tubulopathy Gitelman syndrome. Based on published studies of this polymorphism in SLC12A3 and the features of the proband's father, we postulate that this polymorphism modifies the phenotype of Bartter syndrome in the proband to thiazide resistance. PMID:22245519

  15. Corrosion resistance of the AISI 304, 316 and 321 stainless steel surfaces modified by laser

    NASA Astrophysics Data System (ADS)

    Szubzda, B.; Antończak, A.; Kozioł, P.; Łazarek, Ł.; Stępak, B.; Łęcka, K.; Szmaja, A.; Ozimek, M.

    2016-02-01

    The article presents the analysis results of the influence of laser fluence on physical and chemical structure and corrosion resistance of stainless steel surfaces modified by irradiating with nanosecond-pulsed laser. The study was carried out for AISI 304, AISI 316 and AISI 321 substrates using Yb:glass fiber laser. All measurements were made for samples irradiated in a broad range of accumulated fluence (10÷400 J/cm2). The electrochemical composition (by EDX) and surface morphology (by SEM) of the prepared surfaces were carried out. Finally, corrosion resistance was analyzed by a potentiodynamic electrochemical test. The obtained results showed very high corrosion resistance for samples made by fluency of values lower than 100 J/cm2. In this case, higher values of corrosion potentials and breakdown potentials were observed. A correlation between corrosion phenomena, the range of laser power (fluence) and the results of chemical and structural tests were also found.

  16. Resistance Management Monitoring for the US Corn Crop to the Illinois Corn Growers Association

    EPA Science Inventory

    Significant increases in genetically modified corn planting are expected for future planted acreages approaching 80% of total corn plantings anticipated by 2009. As demand increases, incidence of farmer non-compliance with mandated non-genetically modified refuge is likely to in...

  17. Use of spectral imaging for insect resistance monitoring: EPA research on stewardship of Bt crops

    EPA Science Inventory

    A significant increase in genetically modified corn planting driven by biofuel demand is expected for future growing seasons. As demand increases, incidence of farmer non-compliance with mandated non-genetically modified refuge is likely to increase. As part of the FIFRA regist...

  18. Distribution of Glyphosate-Resistant Horseweed (Conyza Canadensis) and Relationship to Cropping Systems in the Central Valley of California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Horseweed is an increasing problem in perennial crops and non-crop areas of the Central Valley of California. Similar to the situation in glyphosate-tolerant crops in other regions, glyphosate-based weed management strategies in perennial crops and non-crop areas have resulted in selection of a gly...

  19. Yeast cell wall extract induces disease resistance against bacterial and fungal pathogens in Arabidopsis thaliana and Brassica crop.

    PubMed

    Narusaka, Mari; Minami, Taichi; Iwabuchi, Chikako; Hamasaki, Takashi; Takasaki, Satoko; Kawamura, Kimito; Narusaka, Yoshihiro

    2015-01-01

    Housaku Monogatari (HM) is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA) pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods. PMID:25565273

  20. Yeast Cell Wall Extract Induces Disease Resistance against Bacterial and Fungal Pathogens in Arabidopsis thaliana and Brassica Crop

    PubMed Central

    Narusaka, Mari; Minami, Taichi; Iwabuchi, Chikako; Hamasaki, Takashi; Takasaki, Satoko; Kawamura, Kimito; Narusaka, Yoshihiro

    2015-01-01

    Housaku Monogatari (HM) is a plant activator prepared from a yeast cell wall extract. We examined the efficacy of HM application and observed that HM treatment increased the resistance of Arabidopsis thaliana and Brassica rapa leaves to bacterial and fungal infections. HM reduced the severity of bacterial leaf spot and anthracnose on A. thaliana and Brassica crop leaves with protective effects. In addition, gene expression analysis of A. thaliana plants after treatment with HM indicated increased expression of several plant defense-related genes. HM treatment appears to induce early activation of jasmonate/ethylene and late activation of salicylic acid (SA) pathways. Analysis using signaling mutants revealed that HM required SA accumulation and SA signaling to facilitate resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Colletotrichum higginsianum. In addition, HM-induced resistance conferred chitin-independent disease resistance to bacterial pathogens in A. thaliana. These results suggest that HM contains multiple microbe-associated molecular patterns that activate defense responses in plants. These findings suggest that the application of HM is a useful tool that may facilitate new disease control methods. PMID:25565273

  1. Effects of a new modifier on the water-resistance of magnesite cement tiles

    NASA Astrophysics Data System (ADS)

    Xu, Kejing; Xi, Jintao; Guo, Yanqing; Dong, Shuhua

    2012-01-01

    The magnesium oxychloride composite is an inorganic cementitious material with high bending and compression strength in air characteristics. However its strength decreases significantly after immersion in water. The preparing process of a new magnesite cement tile using nano rice husk ashes and a complex water-resistance agent as modifiers was described in the paper. The effects of low-temperature rice husk ashes (RHAs) and the complex water-resistance agent constituted with phosphoric acid, calcium superphosphate, wooden calcium and styrene-acrylic emulsion on the water-resistance of magnesite materials were mainly studied. The samples properties were characterized by XRD, SEM, BET, a laser particle size analyzer and bending test. The experiments show that the proportional addition of nano RHAs markedly increases the water-resistance of magnesite materials without reducing the bending strength and promotes the softening coefficient from 0.29 to 0.78, while the softening coefficient reaches up to 0.97 combined with the use of complex water-resistance agent. The new magnesite cement tiles prepared were not scumming, not warping, and not contracting at room temperature for 360 d.

  2. Spatial variation in soil penetration resistance according to the structural states of the soil and soybean crop yield

    NASA Astrophysics Data System (ADS)

    Wilson, Marcelo; Sasal, María Carolina; Oszust, José; Gabioud, Emmanuel; Melchiori, Ricardo

    2013-04-01

    The soil penetration resistance (PR) is used to identify and characterize soil layers densified by effects of tilling, and the results obtained are related to root growth and crop productivity. The aims of this work were: (i) to analyze the spatial variation in PR through resistance isolines in an Aquic Argiudoll with different long-term cropping sequences under no tillage (NT), (ii) to compare the information generated from the lines with the same PR values with the analysis of the cultural profile and (iii) to study the spatial variability in the PR and the bulk density (BD) in a 10-ha plot, and their relationship with soybean crop yield. An experiment was carried out in an Aquic Argiudoll in 100-m2 plots (4 m wide x 25 m long), with different long-term cropping sequences, under NT for 15 years. The treatments tested were: soybean and maize monocultures, wheat/soybean, wheat/soybean-maize and a permanent pasture as a reference. A digital penetrologger Eijkelkamp ® was used to take 20 measurements of the PR in each plot, through the design of a grid 5 m long and 0.66 m wide, centimeter-wise until 20 cm, totaling n= 400. In addition, an observation well (1 m wide by 30 cm deep) was analyzed by means of the technique of the cultural profiles. Besides, two sampling grids in a 10-ha plot with maize-wheat/soybean sequence were used to measure PR every 30 m and BD every 60 m. The variability in the soil properties was assessed using descriptive statistical analysis, determining normality and spatial variability with the adjustment to the theoretical semivariograms. At 10-15 and 15-20 cm, wheat/soybean-maize and wheat/soybean showed the highest PR values, differentiating from the soybeans and maize monocultures and pasture. The lines with the same PR values allowed observing structural changes in the soil profile, such as surface granular structures and subsequent layers of laminar structure, sometimes discontinuous, from 1.0 to 1.5 MPa between 5 and 8 cm in depth, and

  3. Particle-by-Particle Charge Analysis of DNA-Modified Nanoparticles Using Tunable Resistive Pulse Sensing.

    PubMed

    Blundell, Emma L C J; Vogel, Robert; Platt, Mark

    2016-02-01

    Resistive pulse sensors, RPS, are allowing the transport mechanism of molecules, proteins and even nanoparticles to be characterized as they traverse pores. Previous work using RPS has shown that the size, concentration and zeta potential of the analyte can be measured. Here we use tunable resistive pulse sensing (TRPS) which utilizes a tunable pore to monitor the translocation times of nanoparticles with DNA modified surfaces. We start by demonstrating that the translocation times of particles can be used to infer the zeta potential of known standards and then apply the method to measure the change in zeta potential of DNA modified particles. By measuring the translocation times of DNA modified nanoparticles as a function of packing density, length, structure, and hybridization time, we observe a clear difference in zeta potential using both mean values and population distributions as a function of the DNA structure. We demonstrate the ability to resolve the signals for ssDNA, dsDNA, small changes in base length for nucleotides between 15 and 40 bases long, and even the discrimination between partial and fully complementary target sequences. Such a method has potential and applications in sensors for the monitoring of nanoparticles in both medical and environmental samples. PMID:26757237

  4. Metalaxyl-M-Resistant Pythium Species in Potato Cropping Systems in the Pacific Northwest, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several Pythium spp. causing leak on potato (Solanum tuberosum) are managed by the systemic fungicide metalaxyl-M (mefenoxam). Metalaxyl-M-resistant (MR) isolates of Pythium spp. have been identified in potato production areas of the U.S, but detailed information on the occurrence of resistance is ...

  5. Recombinase Polymerase Amplification (RPA) of CaMV-35S Promoter and nos Terminator for Rapid Detection of Genetically Modified Crops

    PubMed Central

    Xu, Chao; Li, Liang; Jin, Wujun; Wan, Yusong

    2014-01-01

    Recombinase polymerase amplification (RPA) is a novel isothermal DNA amplification and detection technology that enables the amplification of DNA within 30 min at a constant temperature of 37–42 °C by simulating in vivo DNA recombination. In this study, based on the regulatory sequence of the cauliflower mosaic virus 35S (CaMV-35S) promoter and the Agrobacterium tumefaciens nopaline synthase gene (nos) terminator, which are widely incorporated in genetically modified (GM) crops, we designed two sets of RPA primers and established a real-time RPA detection method for GM crop screening and detection. This method could reliably detect as few as 100 copies of the target molecule in a sample within 15–25 min. Furthermore, the real-time RPA detection method was successfully used to amplify and detect DNA from samples of four major GM crops (maize, rice, cotton, and soybean). With this novel amplification method, the test time was significantly shortened and the reaction process was simplified; thus, this method represents an effective approach to the rapid detection of GM crops. PMID:25310647

  6. Responses of plants and invertebrate trophic groups to contrasting herbicide regimes in the Farm Scale Evaluations of genetically modified herbicide-tolerant crops.

    PubMed

    Hawes, C; Haughton, A J; Osborne, J L; Roy, D B; Clark, S J; Perry, J N; Rothery, P; Bohan, D A; Brooks, D R; Champion, G T; Dewar, A M; Heard, M S; Woiwod, I P; Daniels, R E; Young, M W; Parish, A M; Scott, R J; Firbank, L G; Squire, G R

    2003-11-29

    Effects of genetically modified herbicide-tolerant (GMHT) and conventional crop management on invertebrate trophic groups (herbivores, detritivores, pollinators, predators and parasitoids) were compared in beet, maize and spring oilseed rape sites throughout the UK. These trophic groups were influenced by season, crop species and GMHT management. Many groups increased twofold to fivefold in abundance between early and late summer, and differed up to 10-fold between crop species. GMHT management superimposed relatively small (less than twofold), but consistent, shifts in plant and insect abundance, the extent and direction of these effects being dependent on the relative efficacies of comparable conventional herbicide regimes. In general, the biomass of weeds was reduced under GMHT management in beet and spring oilseed rape and increased in maize compared with conventional treatments. This change in resource availability had knock-on effects on higher trophic levels except in spring oilseed rape where herbivore resource was greatest. Herbivores, pollinators and natural enemies changed in abundance in the same directions as their resources, and detritivores increased in abundance under GMHT management across all crops. The result of the later herbicide application in GMHT treatments was a shift in resource from the herbivore food web to the detritivore food web. The Farm Scale Evaluations have demonstrated over 3 years and throughout the UK that herbivores, detritivores and many of their predators and parasitoids in arable systems are sensitive to the changes in weed communities that result from the introduction of new herbicide regimes. PMID:14561321

  7. Invertebrate responses to the management of genetically modified herbicide-tolerant and conventional spring crops. I. Soil-surface-active invertebrates.

    PubMed

    Brooks, D R; Bohan, D A; Champion, G T; Haughton, A J; Hawes, C; Heard, M S; Clark, S J; Dewar, A M; Firbank, L G; Perry, J N; Rothery, P; Scott, R J; Woiwod, I P; Birchall, C; Skellern, M P; Walker, J H; Baker, P; Bell, D; Browne, E L; Dewar, A J G; Fairfax, C M; Garner, B H; Haylock, L A; Horne, S L; Hulmes, S E; Mason, N S; Norton, L R; Nuttall, P; Randle, Z; Rossall, M J; Sands, R J N; Singer, E J; Walker, M J

    2003-11-29

    The effects of herbicide management of genetically modified herbicide-tolerant (GMHT) beet, maize and spring oilseed rape on the abundance and diversity of soil-surface-active invertebrates were assessed. Most effects did not differ between years, environmental zones or initial seedbanks or between sugar and fodder beet. This suggests that the results may be treated as generally applicable to agricultural situations throughout the UK for these crops. The direction of the effects was evenly balanced between increases and decreases in counts in the GMHT compared with the conventional treatment. Most effects involving a greater capture in the GMHT treatments occurred in maize, whereas most effects involving a smaller capture were in beet and spring oilseed rape. Differences between GMHT and conventional crop herbicide management had a significant effect on the capture of most surface-active invertebrate species and higher taxa tested in at least one crop, and these differences reflected the phenology and ecology of the invertebrates. Counts of carabids that feed on weed seeds were smaller in GMHT beet and spring oilseed rape but larger in GMHT maize. In contrast, collembolan detritivore counts were significantly larger under GMHT crop management. PMID:14561318

  8. Recombinase polymerase amplification (RPA) of CaMV-35S promoter and nos terminator for rapid detection of genetically modified crops.

    PubMed

    Xu, Chao; Li, Liang; Jin, Wujun; Wan, Yusong

    2014-01-01

    Recombinase polymerase amplification (RPA) is a novel isothermal DNA amplification and detection technology that enables the amplification of DNA within 30 min at a constant temperature of 37-42 °C by simulating in vivo DNA recombination. In this study, based on the regulatory sequence of the cauliflower mosaic virus 35S (CaMV-35S) promoter and the Agrobacterium tumefaciens nopaline synthase gene (nos) terminator, which are widely incorporated in genetically modified (GM) crops, we designed two sets of RPA primers and established a real-time RPA detection method for GM crop screening and detection. This method could reliably detect as few as 100 copies of the target molecule in a sample within 15-25 min. Furthermore, the real-time RPA detection method was successfully used to amplify and detect DNA from samples of four major GM crops (maize, rice, cotton, and soybean). With this novel amplification method, the test time was significantly shortened and the reaction process was simplified; thus, this method represents an effective approach to the rapid detection of GM crops. PMID:25310647

  9. Age hardening and creep resistance of cast Al–Cu alloy modified by praseodymium

    SciTech Connect

    Bai, Zhihao; Qiu, Feng; Wu, Xiaoxue; Liu, Yingying; Jiang, Qichuan

    2013-12-15

    The effects of praseodymium on age hardening behavior and creep resistance of cast Al–Cu alloy were investigated. The results indicated that praseodymium facilitated the formation of the θ′ precipitates during the age process and improved the hardness of the Al–Cu alloy. Besides, praseodymium resulted in the formation of the Al{sub 11}Pr{sub 3} phase in the grain boundaries and among the dendrites of the modified alloy. Because of the good thermal stability of Al{sub 11}Pr{sub 3} phase, it inhibits grain boundary migration and dislocation movement during the creep process, which contributes to the improvement in the creep resistance of the modified alloy at elevated temperatures. - Highlights: • Pr addition enhances the hardness and creep resistance of the Al–Cu alloy. • Pr addition facilitates the formation of the θ′ precipitates. • Pr addition results in the formation of the Al11Pr3 phase in the Al–Cu alloy.

  10. A strategy to provide long-term control of weedy rice while mitigating herbicide resistance transgene flow, and its potential use for other crops with related weeds.

    PubMed

    Gressel, Jonathan; Valverde, Bernal E

    2009-07-01

    Transgenic herbicide-resistant rice is needed to control weeds that have evolved herbicide resistance, as well as for the weedy (feral, red) rice problem, which has been exacerbated by shifting to direct seeding throughout the world-firstly in Europe and the Americas, and now in Asia, as well as in parts of Africa. Transplanting had been the major method of weedy rice control. Experience with imidazolinone-resistant rice shows that gene flow to weedy rice is rapid, negating the utility of the technology. Transgenic technologies are available that can contain herbicide resistance within the crop (cleistogamy, male sterility, targeting to chloroplast genome, etc.), but such technologies are leaky. Mitigation technologies tandemly couple (genetically link) the gene of choice (herbicide resistance) with mitigation genes that are neutral or good for the crop, but render hybrids with weedy rice and their offspring unfit to compete. Mitigation genes confer traits such as non-shattering, dwarfism, no secondary dormancy and herbicide sensitivity. It is proposed to use glyphosate and glufosinate resistances separately as genes of choice, and glufosinate, glyphosate and bentazone susceptibilities as mitigating genes, with a six-season rotation where each stage kills transgenic crop volunteers and transgenic crop x weed hybrids from the previous season. PMID:19367567

  11. The present state of research and exploitation of biotech (GM) crops in horticulture: results of research on plum cv. 'HoneySweet' resistant to plum pox virus (Sharka) and the deregulation of this cultivar in the CR & Europe

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gentically modified (GM) crops were grown world-wide on 160 million ha in 2011. Only 114.57 ha of GM crops were grown in Europe, of that, 114.90 ha were Bt maize and 17 ha were potato for industrial starch production. Commercialization of Biotech crops started in 1995. Currently, developing count...

  12. Interactions of Tillage and Cover Crop on Water, Sediment, and Pre-emergence Herbicide Loss in Glyphosate-Resistant Cotton: Implications for the Control of Glyphosate-Resistant Weed Biotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The need to control glyphosate [N-(phosphonomethyl)glycine]-resistant weed biotypes with tillage and pre-emergence herbicides in glyphosate-resistant crops (GRCs) is causing a reduction in no-tillage hectarage thereby threatening the advances made in water quality over the past decade. Consequently...

  13. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China.

    PubMed

    Liu, Xin; Wang, Sufen; Xue, Han; Singh, Vijay P

    2015-01-01

    Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China. PMID:26439928

  14. Simulating Crop Evapotranspiration Response under Different Planting Scenarios by Modified SWAT Model in an Irrigation District, Northwest China

    PubMed Central

    Liu, Xin; Wang, Sufen; Xue, Han; Singh, Vijay P.

    2015-01-01

    Modelling crop evapotranspiration (ET) response to different planting scenarios in an irrigation district plays a significant role in optimizing crop planting patterns, resolving agricultural water scarcity and facilitating the sustainable use of water resources. In this study, the SWAT model was improved by transforming the evapotranspiration module. Then, the improved model was applied in Qingyuan Irrigation District of northwest China as a case study. Land use, soil, meteorology, irrigation scheduling and crop coefficient were considered as input data, and the irrigation district was divided into subdivisions based on the DEM and local canal systems. On the basis of model calibration and verification, the improved model showed better simulation efficiency than did the original model. Therefore, the improved model was used to simulate the crop evapotranspiration response under different planting scenarios in the irrigation district. Results indicated that crop evapotranspiration decreased by 2.94% and 6.01% under the scenarios of reducing the planting proportion of spring wheat (scenario 1) and summer maize (scenario 2) by keeping the total cultivated area unchanged. However, the total net output values presented an opposite trend under different scenarios. The values decreased by 3.28% under scenario 1, while it increased by 7.79% under scenario 2, compared with the current situation. This study presents a novel method to estimate crop evapotranspiration response under different planting scenarios using the SWAT model, and makes recommendations for strategic agricultural water management planning for the rational utilization of water resources and development of local economy by studying the impact of planting scenario changes on crop evapotranspiration and output values in the irrigation district of northwest China. PMID:26439928

  15. Evidence of Field-Evolved Resistance of Spodoptera frugiperda to Bt Corn Expressing Cry1F in Brazil That Is Still Sensitive to Modified Bt Toxins

    PubMed Central

    Monnerat, Rose; Martins, Erica; Macedo, Cristina; Queiroz, Paulo; Praça, Lilian; Soares, Carlos Marcelo; Moreira, Helio; Grisi, Isabella; Silva, Joseane; Soberon, Mario; Bravo, Alejandra

    2015-01-01

    Brazil ranked second only to the United States in hectares planted to genetically modified crops in 2013. Recently corn producers in the Cerrado region reported that the control of Spodoptera frugiperda with Bt corn expressing Cry1Fa has decreased, forcing them to use chemicals to reduce the damage caused by this insect pest. A colony of S. frugiperda was established from individuals collected in 2013 from Cry1Fa corn plants (SfBt) in Brazil and shown to have at least more than ten-fold higher resistance levels compared with a susceptible colony (Sflab). Laboratory assays on corn leaves showed that in contrast to SfLab population, the SfBt larvae were able to survive by feeding on Cry1Fa corn leaves. The SfBt population was maintained without selection for eight generations and shown to maintain high levels of resistance to Cry1Fa toxin. SfBt showed higher cross-resistance to Cry1Aa than to Cry1Ab or Cry1Ac toxins. As previously reported, Cry1A toxins competed the binding of Cry1Fa to brush border membrane vesicles (BBMV) from SfLab insects, explaining cross-resistance to Cry1A toxins. In contrast Cry2A toxins did not compete Cry1Fa binding to SfLab-BBMV and no cross-resistance to Cry2A was observed, although Cry2A toxins show low toxicity to S. frugiperda. Bioassays with Cry1AbMod and Cry1AcMod show that they are highly active against both the SfLab and the SfBt populations. The bioassay data reported here show that insects collected from Cry1Fa corn in the Cerrado region were resistant to Cry1Fa suggesting that resistance contributed to field failures of Cry1Fa corn to control S. frugiperda. PMID:25830928

  16. Evidence of field-evolved resistance of Spodoptera frugiperda to Bt corn expressing Cry1F in Brazil that is still sensitive to modified Bt toxins.

    PubMed

    Monnerat, Rose; Martins, Erica; Macedo, Cristina; Queiroz, Paulo; Praça, Lilian; Soares, Carlos Marcelo; Moreira, Helio; Grisi, Isabella; Silva, Joseane; Soberon, Mario; Bravo, Alejandra

    2015-01-01

    Brazil ranked second only to the United States in hectares planted to genetically modified crops in 2013. Recently corn producers in the Cerrado region reported that the control of Spodoptera frugiperda with Bt corn expressing Cry1Fa has decreased, forcing them to use chemicals to reduce the damage caused by this insect pest. A colony of S. frugiperda was established from individuals collected in 2013 from Cry1Fa corn plants (SfBt) in Brazil and shown to have at least more than ten-fold higher resistance levels compared with a susceptible colony (Sflab). Laboratory assays on corn leaves showed that in contrast to SfLab population, the SfBt larvae were able to survive by feeding on Cry1Fa corn leaves. The SfBt population was maintained without selection for eight generations and shown to maintain high levels of resistance to Cry1Fa toxin. SfBt showed higher cross-resistance to Cry1Aa than to Cry1Ab or Cry1Ac toxins. As previously reported, Cry1A toxins competed the binding of Cry1Fa to brush border membrane vesicles (BBMV) from SfLab insects, explaining cross-resistance to Cry1A toxins. In contrast Cry2A toxins did not compete Cry1Fa binding to SfLab-BBMV and no cross-resistance to Cry2A was observed, although Cry2A toxins show low toxicity to S. frugiperda. Bioassays with Cry1AbMod and Cry1AcMod show that they are highly active against both the SfLab and the SfBt populations. The bioassay data reported here show that insects collected from Cry1Fa corn in the Cerrado region were resistant to Cry1Fa suggesting that resistance contributed to field failures of Cry1Fa corn to control S. frugiperda. PMID:25830928

  17. Less waste corn, more land in soybeans, and the switch to genetically modified crops: trends with important implications to wildlife management

    USGS Publications Warehouse

    Krapu, G.L.; Brandt, D.A.; Cox, R.R., Jr.

    2004-01-01

    An abundance of waste corn, a key food of many wildlife species, has helped make possible the widespread success of wildlife management in the United States over the past half century. We found waste corn post harvest in Nebraska declined by 47% from 1978 to 1998 due primarily to improvements in combine headers resulting in a marked decline in ear loss. The reduction in waste coincided with major declines in fat storage by sandhill cranes and white-fronted geese during spring migration. Sandhill cranes, northern pintails, white-fronted geese, and lesser snow geese avoided soybeans while staging in spring in the Rainwater Basin Area and Central Platte River Valley. These findings and other literature suggest soybeans are a marginal food for wildlife particularly during periods of high energy requirements. Soybean acreage has increased by 600% in the United States since 1950 and now comprises nearly one-quarter of the nation>'s cropland. With over 80% of the soybean crop now in genetically modified varieties and treated with glyphosate, weed seed is becoming scarce in soybean fields leaving limited food for wildlife on 72 million acres of U.S. cropland. We suggest that the combined effect of increasing efficiency of crop harvesting techniques, expansion of soybeans and other crops poorly suited for wildlife nutrient needs, and more efficient weed control through the shift to genetically modified crops may severely limit seed-eating wildlife populations in the future unless ways are found to replace high energy food sources being lost. We encourage more research to gain greater insight into effects of declining food resources on wildlife populations and propose that the conservation title of the 2002 farm bill be used as a mechanism to replace part of the high-energy food being lost due to changes in production agriculture.

  18. Modified live Edwardsiella ictaluri vaccine, AQUAVAC-ESC, lacks multidrug resistance plasmids.

    PubMed

    Lafrentz, Benjamin R; Welch, Timothy J; Shoemaker, Craig A; Drennan, John D; Klesius, Phillip H

    2011-12-01

    Plasmid-mediated antibiotic resistance was first discovered in Edwardsiella ictaluri in the early 1990s, and in 2007 an E. ictaluri isolate harboring an IncA/C plasmid was recovered from a moribund channel catfish Ictalurus punctatus infected with the bacterium. Due to the identification of multidrug resistance plasmids in aquaculture and their potential clinical importance, we sought to determine whether the modified live E. ictaluri vaccine strain in AQUAVAC-ESC harbors such plasmids, so that the use of this vaccine will not directly contribute to the pool of bacteria carrying plasmid-borne resistance. Antimicrobial sensitivity testing of the E. ictaluri parent isolate and vaccine strain demonstrated that both were sensitive to 15 of the 16 antimicrobials tested. Total DNA from each isolate was analyzed by polymerase chain reaction (PCR) using a set of 13 primer pairs specific for conserved regions of the IncA/C plasmid backbone, and no specific products were obtained. PCR-based replicon typing of the parent isolate and vaccine strain demonstrated the absence of the 18 commonly occurring plasmid incompatibility groups. These results demonstrate that the vaccine strain does not carry resistance to commonly used antimicrobials and provide strong support for the absence of IncA/C and other commonly occurring plasmid incompatibility groups. Therefore, its use should not directly contribute to the pool of bacteria carrying plasmid-borne resistance. This work highlights the importance of thoroughly investigating potential vaccine strains for the presence of plasmids or other transmissible elements that may encode resistance to antibiotics. PMID:22372247

  19. Limited Fitness Advantages of Crop-Weed Hybrid Progeny Containing Insect-Resistant Transgenes (Bt/CpTI) in Transgenic Rice Field

    PubMed Central

    Yang, Xiao; Wang, Feng; Su, Jun; Lu, Bao-Rong

    2012-01-01

    Background The spread of insect-resistance transgenes from genetically engineered (GE) rice to its coexisting weedy rice (O. sativa f. spontanea) populations via gene flow creates a major concern for commercial GE rice cultivation. Transgene flow to weedy rice seems unavoidable. Therefore, characterization of potential fitness effect brought by the transgenes is essential to assess environmental consequences caused by crop-weed transgene flow. Methodology/Principal Findings Field performance of fitness-related traits was assessed in advanced hybrid progeny of F4 generation derived from a cross between an insect-resistant transgenic (Bt/CpTI) rice line and a weedy strain. The performance of transgene-positive hybrid progeny was compared with the transgene-negative progeny and weedy parent in pure and mixed planting of transgenic and nontransgenic plants under environmental conditions with natural vs. low insect pressure. Results showed that under natural insect pressure the insect-resistant transgenes could effectively suppress target insects and bring significantly increased fitness to transgenic plants in pure planting, compared with nontransgenic plants (including weedy parent). In contrast, no significant differences in fitness were detected under low insect pressure. However, such increase in fitness was not detected in the mixed planting of transgenic and nontransgenic plants due to significantly reduced insect pressure. Conclusions/Significance Insect-resistance transgenes may have limited fitness advantages to hybrid progeny resulted from crop-weed transgene flow owning to the significantly reduced ambient target insect pressure when an insect-resistant GE crop is grown. Given that the extensive cultivation of an insect-resistant GE crop will ultimately reduce the target insect pressure, the rapid spread of insect-resistance transgenes in weedy populations in commercial GE crop fields may be not likely to happen. PMID:22815975

  20. Modified Bacillus thuringiensis Toxins and a Hybrid B. thuringiensis Strain Counter Greenhouse-Selected Resistance in Trichoplusia ni▿

    PubMed Central

    Franklin, Michelle T.; Nieman, Christal L.; Janmaat, Alida F.; Soberón, Mario; Bravo, Alejandra; Tabashnik, Bruce E.; Myers, Judith H.

    2009-01-01

    Resistance of greenhouse-selected strains of the cabbage looper, Trichoplusia ni, to Bacillus thuringiensis subsp. kurstaki was countered by a hybrid strain of B. thuringiensis and genetically modified toxins Cry1AbMod and Cry1AcMod, which lack helix α-1. Resistance to Cry1AbMod and Cry1AcMod was >100-fold less than resistance to native toxins Cry1Ab and Cry1Ac. PMID:19592525

  1. Comparative Effectiveness of Potential Elicitors of Plant Resistance against Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) in Four Crop Plants

    PubMed Central

    Gordy, John W.; Leonard, B. Rogers; Blouin, David; Davis, Jeffrey A.; Stout, Michael J.

    2015-01-01

    Feeding by insect herbivores activates plant signaling pathways, resulting in the enhanced production of secondary metabolites and other resistance-related traits by injured plants. These traits can reduce insect fitness, deter feeding, and attract beneficial insects. Organic and inorganic chemicals applied as a foliar spray, seed treatment, or soil drench can activate these plant responses. Azelaic acid (AA), benzothiadiazole (BTH), gibberellic acid (GA), harpin, and jasmonic acid (JA) are thought to directly mediate plant responses to pathogens and herbivores or to mimic compounds that do. The effects of these potential elicitors on the induction of plant defenses were determined by measuring the weight gains of fall armyworm, Spodoptera frugiperda (J. E. Smith) (FAW) (Lepidoptera: Noctuidae) larvae on four crop plants, cotton, corn, rice, and soybean, treated with the compounds under greenhouse conditions. Treatment with JA consistently reduced growth of FAW reared on treated cotton and soybean. In contrast, FAW fed BTH- and harpin-treated cotton and soybean tissue gained more weight than those fed control leaf tissue, consistent with negative crosstalk between the salicylic acid and JA signaling pathways. No induction or inconsistent induction of resistance was observed in corn and rice. Follow-up experiments showed that the co-application of adjuvants with JA failed to increase the effectiveness of induction by JA and that soybean looper [Chrysodeixis includens (Walker)], a relative specialist on legumes, was less affected by JA-induced responses in soybean than was the polyphagous FAW. Overall, the results of these experiments demonstrate that the effectiveness of elicitors as a management tactic will depend strongly on the identities of the crop, the pest, and the elicitor involved. PMID:26332833

  2. Vegetable crops in the Mediterranean basin with an overview of virus resistance.

    PubMed

    Pitrat, Michel

    2012-01-01

    The Mediterranean area (MA) produces about 12% of the world vegetables both for local consumption and for export. With an average consumption of 242 kg per person and per year (and almost 400 kg in Turkey), vegetables are an important part of the Mediterranean diet. Vegetables are cultivated using different cultivation techniques (for instance, open field or protected), and the importance of viruses varies greatly between these growing conditions. Breeding virus-resistant cultivars is a key component of an integrated pest management strategy. The origin and the diversity of the main vegetables are presented with the sources of virus resistance. The center of origin of most vegetables is not in the MA: for instance, tomato, potato, pepper, bean, squash and pumpkin, and sweetpotato have been introduced from the American continent. Very few original sources of resistance against viruses have been described in local landraces from the MA. PMID:22682164

  3. Thermal-fatigue and oxidation resistance of cobalt-modified Udimet 700 alloy

    NASA Technical Reports Server (NTRS)

    Bizon, P. T.; Barrow, B. J.

    1986-01-01

    Comparative thermal-fatigue and oxidation resistances of cobalt-modified wrought Udimet 700 alloy (obtained by reducing the cobalt level by direct substitution of nickel) were determined from fluidized-bed tests. Bed temperatures were 1010 and 288 C (1850 and 550 C) for the first 5500 symmetrical 6-min cycles. From cycle 5501 to the 14000-cycle limit of testing, the heating bed temperature was increased to 1050 C (1922 F). Cobalt levels between 0 and 17 wt% were studied in both the bare and NiCrAlY overlay coated conditions. A cobalt level of about 8 wt% gave the best thermal-fatigue life. The conventional alloy specification is for 18.5% cobalt, and hence, a factor of 2 in savings of cobalt could be achieved by using the modified alloy. After 13500 cycles, all bare cobalt-modified alloys lost 10 to 13 percent of their initial weight. Application of the NiCrAlY overlay coating resulted in weight losses of 1/20 to 1/100 of that of the corresponding bare alloy.

  4. Interactions of tillage and cover crop on runoff water quality from glyphosate-resistant cotton systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conservation management systems need to be optimized for glyphosate [N-(phosphonomethyl)glycine]-resistant cotton (Gossypium hirsutum L.) (GRC) in the lower Mississippi River alluvial basin to balance production goals with environmental concerns. A rainfall simulation study was conducted in experim...

  5. Genomic tools for developing markers for postharvest disease resistance in Rosaceae fruit crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A wealth of new plant genomic information and molecular tools have been developed over the past ten years and now the challenge is to learn how to apply this information to address critical production problems, such as disease resistance and abiotic stress tolerance. Malus sieversii, an apple speci...

  6. Non-target Risk Assessment for Crops Engineered for Insect Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacillus thuringiensis (Bt) maize genetically engineered (GE) for resistance to the European corn borer has been commercially available in the United States since 1996. Bt maize has been popular with most U.S. growers because it provides economic advantages and reduces the reliance on chemical insec...

  7. Enhanced pest resistance of maize leaves expressing monocot crop plant derived ribosome inactivating protein and agglutinin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although many insect resistance genes have been identified, the number of studies examining their effects in combination using transgenic systems is limited. We introduced a construct into maize containing the coding sequence for maize ribosome inactivating protein (MRIP), wheat germ agglutinin (WGA...

  8. Up-regulation of a H(+)-pyrophosphatase (H(+)-PPase) as a strategy to engineer drought-resistant crop plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Engineering drought-resistant crop plants is a critically important objective. Overexpression of the vacuolar H(+)-pyrophosphatase (H(+)-PPase) AVP1 in the model plant Arabidopsis thaliana results in enhanced performance under soil water deficits. Recent work demonstrates that AVP1 plays an importa...

  9. High residue cover crops alone or with strategic tillage to manage glyphosate-resistant palmer amaranth (amaranthus palmeri) in Southeastern cotton (gossypium hirsutum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate-resistant (GR) Palmer amaranth (Amaranthus palmeri S. Wats) is redefining row crop weed management in the Southeast due to its widespread distribution, high competitive ability, copious seed production, and resilience to standard weed management programs. Herbicides alone are failing to p...

  10. Late-season grass weed management with in-crop and post-harvest herbicides in twin-row glyphosate-resistant soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 3-yr field study was conducted from 2011 to 2013 at Stoneville, MS to determine efficacy of post-harvest and pyroxasulfone-based in-crop herbicides on late-season grasses and yield in twin-row glyphosate-resistant (GR) soybean. Experiments were conducted in a split-plot arrangement of treatments i...

  11. In-Crop and Autumn-Applied Glyphosate Reduced Purple Nutsedge (Cyperus rotundus)Density in No-Till Glyphosate-Resistant Corn and Soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 3-yr field study was conducted from 2005 to 2007 at Stoneville, MS to determine efficacy of in-crop and fall-applied glyphosate on purple nutsedge density and yield of no-till glyphosate-resistant (GR) corn and GR soybean. Separate experiments were conducted in GR corn and GR soybean in areas main...

  12. Dose-dependent RNAi-mediated geminivirus resistance in the tropical root crop cassava.

    PubMed

    Vanderschuren, Hervé; Alder, Adrian; Zhang, Peng; Gruissem, Wilhelm

    2009-06-01

    Cassava mosaic disease is a major constraint for cassava production in Africa, resulting in significant economic losses. We have engineered transgenic cassava with resistance to African cassava mosaic virus (ACMV), by expressing ACMV AC1-homologous hairpin double-strand RNAs. Transgenic cassava lines with high levels of AC1-homologous small RNAs have ACMV immunity with increasing viral load and different inoculation methods. We report a correlation between the expression of the AC1-homologous small RNAs and the ACMV resistance of the transgenic cassava lines. Characterization of the small RNAs revealed that only some of the hairpin-derived small RNAs fall into currently known small interfering RNA classes in plants. The method is scalable to stacking by targeting multiple virus isolates with additional hairpins. PMID:19300911

  13. Allergenicity Assessment of Allium sativum Leaf Agglutinin, a Potential Candidate Protein for Developing Sap Sucking Insect Resistant Food Crops

    PubMed Central

    Mondal, Hossain Ali; Chakraborti, Dipankar; Majumder, Pralay; Roy, Pampa; Roy, Amit; Bhattacharya, Swati Gupta; Das, Sampa

    2011-01-01

    Background Mannose-binding Allium sativum leaf agglutinin (ASAL) is highly antinutritional and toxic to various phloem-feeding hemipteran insects. ASAL has been expressed in a number of agriculturally important crops to develop resistance against those insects. Awareness of the safety aspect of ASAL is absolutely essential for developing ASAL transgenic plants. Methodology/Principal Findings Following the guidelines framed by the Food and Agriculture Organization/World Health Organization, the source of the gene, its sequence homology with potent allergens, clinical tests on mammalian systems, and the pepsin resistance and thermostability of the protein were considered to address the issue. No significant homology to the ASAL sequence was detected when compared to known allergenic proteins. The ELISA of blood sera collected from known allergy patients also failed to show significant evidence of cross-reactivity. In vitro and in vivo assays both indicated the digestibility of ASAL in the presence of pepsin in a minimum time period. Conclusions/Significance With these experiments, we concluded that ASAL does not possess any apparent features of an allergen. This is the first report regarding the monitoring of the allergenicity of any mannose-binding monocot lectin having insecticidal efficacy against hemipteran insects. PMID:22110739

  14. Soil hydrological attributes of an integrated crop-livestock agroecosystem: Increased adaptation through resistance to soil change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Integrated crop-livestock production systems have been suggested to improve agricultural productivity, environmental quality, operational efficiency, and economic performance relative to specialized, single-enterprise production systems. Benefits from crop-livestock integration emanate from product...

  15. Effect of crop plants on fitness costs associated with resistance to Bacillus thuringiensis toxins Cry1Ac and Cry2Ab in cabbage loopers

    PubMed Central

    Wang, Ran; Tetreau, Guillaume; Wang, Ping

    2016-01-01

    Fitness costs associated with resistance to Bacillus thuringiensis (Bt) toxins critically impact the development of resistance in insect populations. In this study, the fitness costs in Trichoplusia ni strains associated with two genetically independent resistance mechanisms to Bt toxins Cry1Ac and Cry2Ab, individually and in combination, on four crop plants (cabbage, cotton, tobacco and tomato) were analyzed, in comparison with their near-isogenic susceptible strain. The net reproductive rate (R0) and intrinsic rate of increase (r) of the T. ni strains, regardless of their resistance traits, were strongly affected by the host plants. The ABCC2 gene-linked mechanism of Cry1Ac resistance was associated with relatively low fitness costs, while the Cry2Ab resistance mechanism was associated with higher fitness costs. The fitness costs in the presence of both resistance mechanisms in T. ni appeared to be non-additive. The relative fitness of Bt-resistant T. ni depended on the specific resistance mechanisms as well as host plants. In addition to difference in survivorship and fecundity, an asynchrony of adult emergence was observed among T. ni with different resistance mechanisms and on different host plants. Therefore, mechanisms of resistance and host plants available in the field are both important factors affecting development of Bt resistance in insects. PMID:26868936

  16. Can we use Electrical Resistivity Tomography to measure root zone moisture dynamics in fields with multiple crops?

    NASA Astrophysics Data System (ADS)

    Garre, S.; Coteur, I.; Wongleecharoen, C.; Diels, J.; Vanderborght, J.

    2012-12-01

    Agriculture on shallow or steep soils in the humid tropics often leads to low resource use efficiency. Contour hedgerow intercropping systems have been proposed to reduce run-off and control soil erosion. However, competition for water and nutrients between crops and associated hedgerows may reduce the overall performance of contour hedgerow systems. Electrical resistivity tomography (ERT) is a valuable technique to assess the distribution and dynamics of soil moisture non-invasively. Root water uptake is a spatially variable and small-scale process, which requires at least decimeter resolution and a high sensitivity in order to be able to monitor changes in time and space. Careful experimental design is of uttermost importance in order to maximize the information content of the ERT survey and to gain insights in the possibilities and limitations of the survey. Virtual experiments in combination with absolute and spatial performance measures provide a way to optimize the information that can be retrieved from an ERT experiment. We used this approach to identify a suitable measurement methodology to monitor water fluxes in a contour hedgerow intercropping system in Ratchaburi province, Thailand. The virtual experiment showed that there are important differences between the tested measurement configurations. We saw that the optimal ERT array was capable of recognizing distinct water depletion zones under the different crops. However, sharp contrasts in the 1-D water depletion profile are smoothened. ERT measurements conducted in Thailand showed that the soils of our experimental plots were very heterogeneous both along the slope as with depth. This observation highlighted some constraints of the ERT method for soil moisture monitoring in the field, such as the difficulty to define a relationship between electrical conductivity and soil moisture in very heterogeneous soils. Nevertheless, the data indeed revealed contrasting water depletion patterns under monocropping

  17. Impact of long-term cropping of glyphosate-resistant transgenic soybean [Glycine max (L.) Merr.] on soil microbiome.

    PubMed

    Babujia, Letícia Carlos; Silva, Adriana Pereira; Nakatani, André Shigueyoshi; Cantão, Mauricio Egidio; Vasconcelos, Ana Tereza Ribeiro; Visentainer, Jesuí Vergilio; Hungria, Mariangela

    2016-08-01

    The transgenic soybean [Glycine max (L.) Merrill] occupies about 80 % of the global area cropped with this legume, the majority comprising the glyphosate-resistant trait (Roundup Ready(®), GR or RR). However, concerns about possible impacts of transgenic crops on soil microbial communities are often raised. We investigated soil chemical, physical and microbiological properties, and grain yields in long-term field trials involving conventional and nearly isogenic RR transgenic genotypes. The trials were performed at two locations in Brazil, with different edaphoclimatic conditions. Large differences in physical, chemical and classic microbiological parameters (microbial biomass of C and N, basal respiration), as well as in grain production were observed between the sites. Some phyla (Proteobacteria, Actinobacteria, Acidobacteria), classes (Alphaproteobacteria, Actinomycetales, Solibacteres) and orders (Rhizobiales, Burkholderiales, Myxococcales, Pseudomonadales), as well as some functional subsystems (clustering-based subsystems, carbohydrates, amino acids and protein metabolism) were, in general, abundant in all treatments. However, bioindicators related to superior soil fertility and physical properties at Londrina were identified, among them a higher ratio of Proteobacteria:Acidobacteria. Regarding the transgene, the metagenomics showed differences in microbial taxonomic and functional abundances, but lower in magnitude than differences observed between the sites. Besides the site-specific differences, Proteobacteria, Firmicutes and Chlorophyta were higher in the transgenic treatment, as well as sequences related to protein metabolism, cell division and cycle. Although confirming effects of the transgenic trait on soil microbiome, no differences were recorded in grain yields, probably due to the buffering capacity associated with the high taxonomic and functional microbial diversity observed in all treatments. PMID:26873023

  18. Chromium-modified a-C films with advanced structural, mechanical and corrosive-resistant characteristics

    NASA Astrophysics Data System (ADS)

    Ming, Miao Yi; Jiang, Xiaohong; Piliptsou, D. G.; Zhuang, Yuzhao; Rogachev, A. V.; Rudenkov, A. S.; Balmakou, A.

    2016-08-01

    To improve structural, mechanical and chemical properties of diamond-like carbon films, we developed amorphous carbon chromium-modified composite films fabricated by means of cathode magnetic filtered arc deposition. The properties were analyzed by Raman spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy for the purpose of the structure characterization, elemental analysis and topology examination. Moreover, we also assessed residual stress, the coefficient of friction, hardness, the elastic modulus and corrosion parameters through X-ray double-crystal surface profilometry, tribo-testing, nanoindenter-testing, as well as contact angle measurements and potentiodynamic polarization analysis. As a result of a comparative analysis, we revealed a substantial improvement in the characteristics of developed composite films in comparison with amorphous carbon films. For example, Cr-modification is resulted, in greater integrated performance, toughness and corrosion resistance; the residual stress was reduced substantially.

  19. Insect-resistant genetically modified rice in China: from research to commercialization.

    PubMed

    Chen, Mao; Shelton, Anthony; Ye, Gong-yin

    2011-01-01

    From the first insect-resistant genetically modified (IRGM) rice transformation in 1989 in China to October 2009 when the Chinese Ministry of Agriculture issued biosafety certificates for commercial production of two cry1Ab/Ac Bacillus thuringiensis (Bt) lines, China made a great leap forward from IRGM rice basic research to potential commercialization of the world's first IRGM rice. Research has been conducted on developing IRGM rice, assessing its environmental and food safety impacts, and evaluating its socioeconomic consequences. Laboratory and field tests have confirmed that these two Bt rice lines can provide effective and economic control of the lepidopteran complex on rice with less risk to the environment than present practices. Commercializing these Bt plants, while developing other GM plants that address the broader complex of insects and other pests, will need to be done within a comprehensive integrated pest management program to ensure the food security of China and the world. PMID:20868281

  20. Distribution of genes encoding aminoglycoside-modifying enzymes among clinical isolates of methicillin-resistant staphylococci.

    PubMed

    Perumal, N; Murugesan, S; Krishnan, P

    2016-01-01

    The objective of this study was to determine the distribution of genes encoding aminoglycoside-modifying enzymes (AMEs) and staphylococcal cassette chromosome mec (SCCmec) elements among clinical isolates of methicillin-resistant staphylococci (MRS). Antibiotic susceptibility test was done using Kirby-Bauer disk diffusion method. The presence of SCCmec types and AME genes, namely, aac (6')-Ie-aph (2''), aph (3')-IIIa and ant (4')-Ia was determined using two different multiplex polymerase chain reaction. The most encountered AME genes were aac (6')-Ie-aph (2'') (55.4%) followed by aph (3')-IIIa (32.3%) and ant (4')-Ia gene (9%). SCCmec type I (34%) was predominant in this study. In conclusion, the aac (6')-Ie-aph (2'') was the most common AME gene and SCCmec type I was most predominant among the MRS isolates. PMID:27514959

  1. Chemically modified Si(111) surfaces simultaneously demonstrating hydrophilicity, resistance against oxidation, and low trap state densities

    NASA Astrophysics Data System (ADS)

    Brown, Elizabeth S.; Hlynchuk, Sofiya; Maldonado, Stephen

    2016-03-01

    Chemically modified Si(111) surfaces have been prepared through a series of wet chemical surface treatments that simultaneously show resistance towards surface oxidation, selective reactivity towards chemical reagents, and areal defect densities comparable to unannealed thermal oxides. Specifically, grazing angle attenuated total reflectance infrared and X-ray photoelectron (XP) spectroscopies were used to characterize allyl-, 3,4-methylenedioxybenzene-, or 4-[bis(trimethylsilyl)amino]phenyl-terminated surfaces and the subsequently hydroxylated surfaces. Hydroxylated surfaces were confirmed through reaction with 4-(trifluoromethyl)benzyl bromide and quantified by XP spectroscopy. Contact angle measurements indicated all surfaces remained hydrophilic, even after secondary backfilling with CH3sbnd groups. Surface recombination velocity measurements by way of microwave photoconductivity transients showed the relative defect-character of as-prepared and aged surfaces. The relative merits for each investigated surface type are discussed.

  2. ETHICAL ISSUES IN FIELD TRIALS OF GENETICALLY MODIFIED DISEASE-RESISTANT MOSQUITOES

    PubMed Central

    RESNIK, DAVID B.

    2012-01-01

    Mosquito-borne diseases take a tremendous toll on human populations, especially in developing nations. In the last decade, scientists have developed mosquitoes that have been genetically modified to prevent transmission of mosquito-borne diseases, and field trials have been conducted. Some mosquitoes have been rendered infertile, some have been equipped with a vaccine they transmit to humans, and some have been designed to resist diseases. This article focuses on ethical issues raised by field trials of disease-resistant, genetically modified mosquitoes. Some of these issues include: protecting the public and the environment from harm, balancing benefits and risks, collaborating with the local community, avoiding exploitation, and safeguarding the rights and welfare of research subjects. One of the most difficult problems involves protecting the welfare of community members who will be impacted by the release of mosquitoes but who are not enrolled in the study as research subjects. To address this concern, field trials should take place only when the targeted disease is a significant public health problem in an isolated area, the benefits of the trial for the community are likely to outweigh the risks, community leaders approve of the trial, and there are measures in place to protect the welfare of un-enrolled community members, such as informing the community about the study and offering free treatment to people who contract mosquito-borne diseases. Since the justification of any field trial depends on a careful examination of the scientific and ethical issues, proposed studies should be evaluated on a case-by-case basis. PMID:23279283

  3. Ethical issues in field trials of genetically modified disease-resistant mosquitoes.

    PubMed

    Resnik, David B

    2014-04-01

    Mosquito-borne diseases take a tremendous toll on human populations, especially in developing nations. In the last decade, scientists have developed mosquitoes that have been genetically modified to prevent transmission of mosquito-borne diseases, and field trials have been conducted. Some mosquitoes have been rendered infertile, some have been equipped with a vaccine they transmit to humans, and some have been designed to resist diseases. This article focuses on ethical issues raised by field trials of disease-resistant, genetically modified mosquitoes. Some of these issues include: protecting the public and the environment from harm, balancing benefits and risks, collaborating with the local community, avoiding exploitation, and safeguarding the rights and welfare of research subjects. One of the most difficult problems involves protecting the welfare of community members who will be impacted by the release of mosquitoes but who are not enrolled in the study as research subjects. To address this concern, field trials should take place only when the targeted disease is a significant public health problem in an isolated area, the benefits of the trial for the community are likely to outweigh the risks, community leaders approve of the trial, and there are measures in place to protect the welfare of un-enrolled community members, such as informing the community about the study and offering free treatment to people who contract mosquito-borne diseases. Since the justification of any field trial depends on a careful examination of the scientific and ethical issues, proposed studies should be evaluated on a case-by-case basis. PMID:23279283

  4. Leaf Treatments with a Protein-Based Resistance Inducer Partially Modify Phyllosphere Microbial Communities of Grapevine.

    PubMed

    Cappelletti, Martina; Perazzolli, Michele; Antonielli, Livio; Nesler, Andrea; Torboli, Esmeralda; Bianchedi, Pier L; Pindo, Massimo; Puopolo, Gerardo; Pertot, Ilaria

    2016-01-01

    Protein derivatives and carbohydrates can stimulate plant growth, increase stress tolerance, and activate plant defense mechanisms. However, these molecules can also act as a nutritional substrate for microbial communities living on the plant phyllosphere and possibly affect their biocontrol activity against pathogens. We investigated the mechanisms of action of a protein derivative (nutrient broth, NB) against grapevine downy mildew, specifically focusing on the effects of foliar treatments on plant defense stimulation and on the composition and biocontrol features of the phyllosphere microbial populations. NB reduced downy mildew symptoms and induced the expression of defense-related genes in greenhouse- and in vitro-grown plants, indicating the activation of grapevine resistance mechanisms. Furthermore, NB increased the number of culturable phyllosphere bacteria and altered the composition of bacterial and fungal populations on leaves of greenhouse-grown plants. Although, NB-induced changes on microbial populations were affected by the structure of indigenous communities originally residing on grapevine leaves, degrees of disease reduction and defense gene modulation were consistent among the experiments. Thus, modifications in the structure of phyllosphere populations caused by NB application could partially contribute to downy mildew control by competition for space or other biocontrol strategies. Particularly, changes in the abundance of phyllosphere microorganisms may provide a contribution to resistance induction, partially affecting the hormone-mediated signaling pathways involved. Modifying phyllosphere populations by increasing natural biocontrol agents with the application of selected nutritional factors can open new opportunities in terms of sustainable plant protection strategies. PMID:27486468

  5. Advanced glycation end-products: modifiable environmental factors profoundly mediate insulin resistance

    PubMed Central

    Ottum, Mona S.; Mistry, Anahita M.

    2015-01-01

    Advanced glycation end-products are toxic by-products of metabolism and are also acquired from high-temperature processed foods. They promote oxidative damage to proteins, lipids and nucleotides. Aging and chronic diseases are strongly associated with markers for oxidative stress, especially advanced glycation end-products, and resistance to peripheral insulin-mediated glucose uptake. Modifiable environmental factors including high levels of refined and simple carbohydrate diets, hypercaloric diets and sedentary lifestyles drive endogenous formation of advanced glycation end-products via accumulation of highly reactive glycolysis intermediates and activation of the polyol/aldose reductase pathway producing high intracellular fructose. High advanced glycation end-products overwhelm innate defenses of enzymes and receptor-mediated endocytosis and promote cell damage via the pro-inflammatory and pro-oxidant receptor for advanced glycation end-products. Oxidative stress disturbs cell signal transduction, especially insulin-mediated metabolic responses. Here we review emerging evidence that restriction of dietary advanced glycation end-products significantly reduces total systemic load and insulin resistance in animals and humans in diabetes, polycystic ovary syndrome, healthy populations and dementia. Of clinical importance, this insulin sensitizing effect is independent of physical activity, caloric intake and adiposity level. PMID:26236094

  6. Leaf Treatments with a Protein-Based Resistance Inducer Partially Modify Phyllosphere Microbial Communities of Grapevine

    PubMed Central

    Cappelletti, Martina; Perazzolli, Michele; Antonielli, Livio; Nesler, Andrea; Torboli, Esmeralda; Bianchedi, Pier L.; Pindo, Massimo; Puopolo, Gerardo; Pertot, Ilaria

    2016-01-01

    Protein derivatives and carbohydrates can stimulate plant growth, increase stress tolerance, and activate plant defense mechanisms. However, these molecules can also act as a nutritional substrate for microbial communities living on the plant phyllosphere and possibly affect their biocontrol activity against pathogens. We investigated the mechanisms of action of a protein derivative (nutrient broth, NB) against grapevine downy mildew, specifically focusing on the effects of foliar treatments on plant defense stimulation and on the composition and biocontrol features of the phyllosphere microbial populations. NB reduced downy mildew symptoms and induced the expression of defense-related genes in greenhouse- and in vitro-grown plants, indicating the activation of grapevine resistance mechanisms. Furthermore, NB increased the number of culturable phyllosphere bacteria and altered the composition of bacterial and fungal populations on leaves of greenhouse-grown plants. Although, NB-induced changes on microbial populations were affected by the structure of indigenous communities originally residing on grapevine leaves, degrees of disease reduction and defense gene modulation were consistent among the experiments. Thus, modifications in the structure of phyllosphere populations caused by NB application could partially contribute to downy mildew control by competition for space or other biocontrol strategies. Particularly, changes in the abundance of phyllosphere microorganisms may provide a contribution to resistance induction, partially affecting the hormone-mediated signaling pathways involved. Modifying phyllosphere populations by increasing natural biocontrol agents with the application of selected nutritional factors can open new opportunities in terms of sustainable plant protection strategies. PMID:27486468

  7. Potatoes - A crop resistant against input of heavy metals from the metallicaly contaminated soil.

    PubMed

    Musilova, Janette; Bystricka, Judita; Lachman, Jaromir; Harangozo, Lubos; Trebichalsky, Pavol; Volnova, Beata

    2016-01-01

    The objective of our study was to assess the extent of accumulation of cadmium, lead and zinc in potato tubers depending on the concentration of these heavy metals in soil and to evaluate the resistance of 11 cultivars of potato cultivated in 5 localities of the Slovakia against input of these heavy metals into the consumption part of potato. Contents of Cd (Pb, Zn) in soil were 0.94-2.54 (18.03-24.90, 35.71-72.40) mg/kg in soil extract by aqua regia and 0.030-0.188 (0.149-0.356, 0.052-0.238) mg/kg in soil extract by NH4NO3. The contents of Cd, Pb, and Zn were determined in potatoes in extracts of freeze-dried samples and expressed in mg/kg of fresh matter (FM). Determined contents of heavy metals were in the range of ND-0.058 mg Cd/kg FM, 0.020-0.630 mg Pb/kg FM, 1.836-3.457 mg Zn/kg FM, resp. The statistically significant correlation between heavy metal content in soil and its content in potato tubers were confirmed only: cv. Laura - Spissky Stvrtok (Cd), cv. Red Anna - Odorin (Pb) and Marabel, Red Anna - Odorin, cv. Marabel - Belusa, cv. Volumia - Imel (Zn). PMID:26421760

  8. Electrochemical sensor for multiplex screening of genetically modified DNA: identification of biotech crops by logic-based biomolecular analysis.

    PubMed

    Liao, Wei-Ching; Chuang, Min-Chieh; Ho, Ja-An Annie

    2013-12-15

    Genetically modified (GM) technique, one of the modern biomolecular engineering technologies, has been deemed as profitable strategy to fight against global starvation. Yet rapid and reliable analytical method is deficient to evaluate the quality and potential risk of such resulting GM products. We herein present a biomolecular analytical system constructed with distinct biochemical activities to expedite the computational detection of genetically modified organisms (GMOs). The computational mechanism provides an alternative to the complex procedures commonly involved in the screening of GMOs. Given that the bioanalytical system is capable of processing promoter, coding and species genes, affirmative interpretations succeed to identify specified GM event in terms of both electrochemical and optical fashions. The biomolecular computational assay exhibits detection capability of genetically modified DNA below sub-nanomolar level and is found interference-free by abundant coexistence of non-GM DNA. This bioanalytical system, furthermore, sophisticates in array fashion operating multiplex screening against variable GM events. Such a biomolecular computational assay and biosensor holds great promise for rapid, cost-effective, and high-fidelity screening of GMO. PMID:23893064

  9. Impact of Adiposity on Incident Hypertension Is Modified by Insulin Resistance in Adults: Longitudinal Observation From the Bogalusa Heart Study.

    PubMed

    Zhang, Tao; Zhang, Huijie; Li, Shengxu; Li, Ying; Liu, Yaozhong; Fernandez, Camilo; Harville, Emily; Bazzano, Lydia; He, Jiang; Chen, Wei

    2016-01-01

    Adiposity and insulin resistance are closely associated with hypertension. This study aims to investigate whether the association between adiposity and hypertension is modified by insulin resistance. The cohort consisted of 1624 middle-aged normotensive black and white adults aged 18 to 43 years at baseline who followed for 16 years on average. Overweight/obesity at baseline was defined as body mass index (BMI) ≥25, and insulin resistance was measured using homeostasis model assessment of insulin resistance. Prevalence of incident hypertension was compared between the insulin-sensitive adiposity and insulin-resistant adiposity groups. The prevalence of incident hypertension was higher in the insulin-resistant adiposity than in the insulin-sensitive adiposity group (32.1% versus 22.1%, P<0.001). In multivariable logistic analyses, adjusted for baseline age, race, sex, follow-up years, and smoking, baseline insulin-resistant obesity was associated with incident hypertension (odds ratio, 1.9; P=0.008). Odds ratios did not differ between blacks and whites (P=0.238). Of note, the odds ratios of BMI associated with hypertension significantly increased with increasing quartiles of baseline homeostasis model assessment (odds ratio, 1.3, 1.1, 1.5, and 2.5 in quartiles I, II, III, and IV, respectively; P=0.006 for trend). Slopes of increasing follow-up blood pressure with baseline BMI, measured as regression coefficients (β), were significantly greater in insulin-resistant than in insulin-sensitive individuals (β=0.74 versus β=0.35 for systolic blood pressure, P=0.004 for difference; β=0.51 versus β=0.23 for diastolic blood pressure, P=0.001 for difference). These findings suggest that insulin resistance has a synergistic effect on the obesity-hypertension association in young adults, indicating that the role of adiposity in the development of hypertension is modified by insulin resistance. PMID:26573703

  10. Insight into the durability of plant resistance to aphids from a demo-genetic study of Aphis gossypii in melon crops.

    PubMed

    Thomas, Sophie; Vanlerberghe-Masutti, Flavie; Mistral, Pascale; Loiseau, Anne; Boissot, Nathalie

    2016-07-01

    Resistance breakdown has been observed following the deployment of plant cultivars resistant to pests. Assessing the durability of a resistance requires long-term experiments at least at a regional scale. We collected such data for melon resistance conferred by the Vat gene cluster to melon aphids. We examined landscape-level populations of Aphis gossypii collected in 2004-2015, from melon-producing regions with and without the deployment of Vat resistance and with different climates. We conducted demo-genetic analyses of the aphid populations on Vat and non-Vat plants during the cropping seasons. The Vat resistance decreased the density of aphid populations in all areas and changed the genetic structure and composition of these populations. Two bottlenecks were identified in the dynamics of adapted clones, due to the low levels of production of dispersal morphs and winter extinction. Our results suggest that (i) Vat resistance will not be durable in the Lesser Antilles, where no bottleneck affected the dynamics of adapted clones, (ii) Vat resistance will be durable in south-west France, where both bottlenecks affected the dynamics of adapted clones and (iii) Vat resistance will be less durable in south-east France, where only one of the two bottlenecks was observed. PMID:27330552

  11. Safely Coupling Livestock and Crop Production Systems: How Rapidly Do Antibiotic Resistance Genes Dissipate in Soil following a Commercial Application of Swine or Dairy Manure?

    PubMed Central

    Marti, Romain; Tien, Yuan-Ching; Murray, Roger; Scott, Andrew; Sabourin, Lyne

    2014-01-01

    Animal manures recycled onto crop production land carry antibiotic-resistant bacteria. The present study evaluated the fate in soil of selected genes associated with antibiotic resistance or genetic mobility in field plots cropped to vegetables and managed according to normal farming practice. Referenced to unmanured soil, fertilization with swine or dairy manure increased the relative abundance of the gene targets sul1, erm(B), str(B), int1, and IncW repA. Following manure application in the spring of 2012, gene copy number decayed exponentially, reaching background levels by the fall of 2012. In contrast, gene copy number following manure application in the fall of 2012 or spring of 2013 increased significantly in the weeks following application and then declined. In both cases, the relative abundance of gene copy numbers had not returned to background levels by the fall of 2013. Overall, these results suggest that under conditions characteristic of agriculture in a humid continental climate, a 1-year period following a commercial application of raw manure is sufficient to ensure that an additional soil burden of antibiotic resistance genes approaches background. The relative abundance of several gene targets exceeded background during the growing season following a spring application or an application done the previous fall. Results from the present study reinforce the advisability of treating manure prior to use in crop production systems. PMID:24632259

  12. Safely coupling livestock and crop production systems: how rapidly do antibiotic resistance genes dissipate in soil following a commercial application of swine or dairy manure?

    PubMed

    Marti, Romain; Tien, Yuan-Ching; Murray, Roger; Scott, Andrew; Sabourin, Lyne; Topp, Edward

    2014-05-01

    Animal manures recycled onto crop production land carry antibiotic-resistant bacteria. The present study evaluated the fate in soil of selected genes associated with antibiotic resistance or genetic mobility in field plots cropped to vegetables and managed according to normal farming practice. Referenced to unmanured soil, fertilization with swine or dairy manure increased the relative abundance of the gene targets sul1, erm(B), str(B), int1, and IncW repA. Following manure application in the spring of 2012, gene copy number decayed exponentially, reaching background levels by the fall of 2012. In contrast, gene copy number following manure application in the fall of 2012 or spring of 2013 increased significantly in the weeks following application and then declined. In both cases, the relative abundance of gene copy numbers had not returned to background levels by the fall of 2013. Overall, these results suggest that under conditions characteristic of agriculture in a humid continental climate, a 1-year period following a commercial application of raw manure is sufficient to ensure that an additional soil burden of antibiotic resistance genes approaches background. The relative abundance of several gene targets exceeded background during the growing season following a spring application or an application done the previous fall. Results from the present study reinforce the advisability of treating manure prior to use in crop production systems. PMID:24632259

  13. Protease-resistant modified human β-hexosaminidase B ameliorates symptoms in GM2 gangliosidosis model.

    PubMed

    Kitakaze, Keisuke; Mizutani, Yasumichi; Sugiyama, Eiji; Tasaki, Chikako; Tsuji, Daisuke; Maita, Nobuo; Hirokawa, Takatsugu; Asanuma, Daisuke; Kamiya, Mako; Sato, Kohei; Setou, Mitsutoshi; Urano, Yasuteru; Togawa, Tadayasu; Otaka, Akira; Sakuraba, Hitoshi; Itoh, Kohji

    2016-05-01

    GM2 gangliosidoses, including Tay-Sachs and Sandhoff diseases, are neurodegenerative lysosomal storage diseases that are caused by deficiency of β-hexosaminidase A, which comprises an αβ heterodimer. There are no effective treatments for these diseases; however, various strategies aimed at restoring β-hexosaminidase A have been explored. Here, we produced a modified human hexosaminidase subunit β (HexB), which we have termed mod2B, composed of homodimeric β subunits that contain amino acid sequences from the α subunit that confer GM2 ganglioside-degrading activity and protease resistance. We also developed fluorescent probes that allow visualization of endocytosis of mod2B via mannose 6-phosphate receptors and delivery of mod2B to lysosomes in GM2 gangliosidosis models. In addition, we applied imaging mass spectrometry to monitor efficacy of this approach in Sandhoff disease model mice. Following i.c.v. administration, mod2B was widely distributed and reduced accumulation of GM2, asialo-GM2, and bis(monoacylglycero)phosphate in brain regions including the hypothalamus, hippocampus, and cerebellum. Moreover, mod2B administration markedly improved motor dysfunction and a prolonged lifespan in Sandhoff disease mice. Together, the results of our study indicate that mod2B has potential for intracerebrospinal fluid enzyme replacement therapy and should be further explored as a gene therapy for GM2 gangliosidoses. PMID:27018595

  14. Protease-resistant modified human β-hexosaminidase B ameliorates symptoms in GM2 gangliosidosis model

    PubMed Central

    Mizutani, Yasumichi; Sugiyama, Eiji; Tasaki, Chikako; Tsuji, Daisuke; Maita, Nobuo; Hirokawa, Takatsugu; Asanuma, Daisuke; Kamiya, Mako; Sato, Kohei; Setou, Mitsutoshi; Urano, Yasuteru; Togawa, Tadayasu; Otaka, Akira; Sakuraba, Hitoshi

    2016-01-01

    GM2 gangliosidoses, including Tay-Sachs and Sandhoff diseases, are neurodegenerative lysosomal storage diseases that are caused by deficiency of β-hexosaminidase A, which comprises an αβ heterodimer. There are no effective treatments for these diseases; however, various strategies aimed at restoring β-hexosaminidase A have been explored. Here, we produced a modified human hexosaminidase subunit β (HexB), which we have termed mod2B, composed of homodimeric β subunits that contain amino acid sequences from the α subunit that confer GM2 ganglioside–degrading activity and protease resistance. We also developed fluorescent probes that allow visualization of endocytosis of mod2B via mannose 6-phosphate receptors and delivery of mod2B to lysosomes in GM2 gangliosidosis models. In addition, we applied imaging mass spectrometry to monitor efficacy of this approach in Sandhoff disease model mice. Following i.c.v. administration, mod2B was widely distributed and reduced accumulation of GM2, asialo-GM2, and bis(monoacylglycero)phosphate in brain regions including the hypothalamus, hippocampus, and cerebellum. Moreover, mod2B administration markedly improved motor dysfunction and a prolonged lifespan in Sandhoff disease mice. Together, the results of our study indicate that mod2B has potential for intracerebrospinal fluid enzyme replacement therapy and should be further explored as a gene therapy for GM2 gangliosidoses. PMID:27018595

  15. Synthesis of oxidation resistant lead nanoparticle films by modified pulsed laser ablation

    SciTech Connect

    Shin, Eunsung; Murray, P. Terrence; Subramanyam, Guru; Malik, Hans K.; Schwartz, Kenneth L.

    2012-07-30

    Thin layers of lead nanoparticles have been produced by a modified pulsed laser ablation (PLA) process in which smaller nanoparticles were swept out of the ablation chamber by a stream of flowing Ar. Large ({mu}m-sized) particles, which are usually deposited during the standard PLA process, were successfully eliminated from the deposit. The nanoparticles deposited on room temperature substrates were well distributed, and the most probable particle diameter was in the order of 30 nm. Since lead is highly reactive, the nanoparticles formed in Ar were quickly oxidized upon exposure to air. A small partial pressure of H{sub 2}S gas was subsequently added to the effluent, downstream from the ablation chamber, and this resulted in the formation of nanoparticle deposits that were surprisingly oxidation resistant. The properties of the nanoparticle films (as determined by transmission electron microscopy, scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and conductivity measurements) are reported, and the mechanism of the oxidation retardation process is discussed.

  16. Synthesis of oxidation resistant lead nanoparticle films by modified pulsed laser ablation

    NASA Astrophysics Data System (ADS)

    Shin, Eunsung; Murray, P. Terrence; Subramanyam, Guru; Malik, Hans K.; Schwartz, Kenneth L.

    2012-07-01

    Thin layers of lead nanoparticles have been produced by a modified pulsed laser ablation (PLA) process in which smaller nanoparticles were swept out of the ablation chamber by a stream of flowing Ar. Large (μm-sized) particles, which are usually deposited during the standard PLA process, were successfully eliminated from the deposit. The nanoparticles deposited on room temperature substrates were well distributed, and the most probable particle diameter was in the order of 30 nm. Since lead is highly reactive, the nanoparticles formed in Ar were quickly oxidized upon exposure to air. A small partial pressure of H2S gas was subsequently added to the effluent, downstream from the ablation chamber, and this resulted in the formation of nanoparticle deposits that were surprisingly oxidation resistant. The properties of the nanoparticle films (as determined by transmission electron microscopy, scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and conductivity measurements) are reported, and the mechanism of the oxidation retardation process is discussed.

  17. Subchronic Immunotoxicity Assessment of Genetically Modified Virus-Resistant Papaya in Rats.

    PubMed

    Lin, Hsin-Tang; Lee, Wei-Cheng; Tsai, Yi-Ting; Wu, Jhaol-Huei; Yen, Gow-Chin; Yeh, Shyi-Dong; Cheng, Ying-Huey; Chang, Shih-Chieh; Liao, Jiunn-Wang

    2016-07-27

    Papaya is an important fruit that provides a variety of vitamins with nutritional value and also holds some pharmacological properties, including immunomodulation. Genetically modified (GM) papaya plants resistant to Papaya ringspot virus (PRSV) infection have been generated by cloning the coat protein gene of the PRSV which can be used as a valuable strategy to fight PRSV infection and to increase papaya production. In order to assess the safety of GM papaya as a food, this subchronic study was conducted to assess the immunomodulatory responses of the GM papaya line 823-2210, when compared with its parent plant of non-GM papaya, Tainung-2 (TN-2), in Sprague-Dawley (SD) rats. Both non-GM and GM 823-2210 papaya fruits at low (1 g/kg bw) and high (2 g/kg bw) dosages were administered via daily oral gavage to male and female rats consecutively for 90 days. Immunophenotyping, mitogen-induced splenic cell proliferation, antigen-specific antibody response, and histopathology of the spleen and thymus were evaluated at the end of the experiment. Results of immunotoxicity assays revealed no consistent difference between rats fed for 90 days with GM 823-2210 papaya fruits, as opposed to those fed non-GM TN-2 papaya fruits, suggesting that with regard to immunomodulatory responses, GM 823-2210 papaya fruits maintain substantial equivalence to fruits of their non-GM TN-2 parent. PMID:27396727

  18. Chemical composition and resistance-modifying effect of the essential oil of Lantana camara Linn

    PubMed Central

    Sousa, Erlânio O.; Silva, Natálya F.; Rodrigues, Fabiola F. G.; Campos, Adriana R.; Lima, Sidney G.; Costa, José Galberto M.

    2010-01-01

    In this work, the chemical constituents, antibacterial and modulatory activities of the essential oil of Lantana camara Linn were studied. The essential oil was extracted from the leaves of L. camara by hydrodistillation method using Clevenger's apparatus and its chemical constituents were separated and identified by GC-MS, and the relative content of each constituent was determined by area normalization. Among the 25 identified components, bicyclogermacrene (19.42%), isocaryophyllene (16.70%), valecene (12.94%) and germacrene D (12.34%) were the main constituents. The oil was examined to antibacterial and modulatory activities against the multiresistant strains of Escherichia coli and Staphylococcus aureus by microdilution test. The results show an inhibitory activity to E. coli (MIC 512 μg/ml) and S. aureus (MIC 256 μg/ml). The synergism of the essential oil and aminoglycosides was verified too, with significant reduction of MICs (7 ×, 1250-5 μg/ml) against E. coli. It is suggested that the essential oil of Lantana camara Linn could be used as a source of plant-derived natural products with resistance-modifying activity. PMID:20668570

  19. Corrosion resistance of Ti modified by chitosan-gold nanoparticles for orthopedic implantation.

    PubMed

    Farghali, R A; Fekry, A M; Ahmed, Rasha A; Elhakim, H K A

    2015-08-01

    Highly uniform bionanocomposite film composed of chitosan (CS) and gold nanoparticles (AuNPs) was synthesized successfully by electrodeposition method. The influence of AuNPs/CS bionanocomposite film on corrosion resistance of Ti was investigated. Surface morphology and compositional properties of the bionanocomposite were analyzed by scanning electron microscope (SEM), energy dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS). Moreover, cyclic voltammetry (CV), open-circuit potential measurements (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (Rp) were used to examine the corrosion behavior in Hanks' solution. In comparison with Ti, Nyquist and Bode plots displayed higher impedance values and phase angles for AuNPs/CS biocomposite denoting a more protective passive film on Ti with inhibition efficiency (IE%) of 98%. An electric equivalent circuit with three time constants was modeled for the bionanocomposite. In addition, the antibacterial effect revealed the high efficiencies of the bionanocomposite film for inhibiting bacterial growth. The combination of the high biocompatibility of chitosan and strong adsorption ability of AuNPs make AuNPs/CS bionanocomposite promising candidate for modifying biomaterial surfaces for medical implantation applications. PMID:25989146

  20. Wing shape and size of the western corn rootworm (Coleoptera: Chrysomelidae) is related to sex and resistance to soybean-maize crop rotation.

    PubMed

    Mikac, K M; Douglas, J; Spencer, J L

    2013-08-01

    The western corn rootworm, Diabrotica virgifera virgifera LeConte, is a major pest of maize in the United States and more recently, Europe. Understanding the dispersal dynamics of this species will provide crucial information for its management. This study used geometric morphometric analysis of hind wing venation based on 13 landmarks in 223 specimens from nine locations in Illinois, Nebraska, Iowa, and Missouri, to assess whether wing shape and size differed between rotated and continuously grown maize where crop rotation-resistant and susceptible individuals are found, respectively. Before assessing differences between rotation-resistant and susceptible individuals, sexual dimorphism was investigated. No significant difference in wing (centroid) size was found between males and females; however, females had significantly different shaped (more elongated) wings compared with males. Wing shape and (centroid) size were significantly larger among individuals from rotated maize where crop-rotation resistance was reported; however, cross-validation of these results revealed that collection site resistance status was an only better than average predictor of shape in males and females. This study provides preliminary evidence of wing shape and size differences in D. v. virgifera from rotated versus continuous maize. Further study is needed to confirm whether wing shape and size can be used to track the movement of rotation-resistant individuals and populations as a means to better inform management strategies. PMID:24020261

  1. Botrytis pseudocinerea Is a Significant Pathogen of Several Crop Plants but Susceptible to Displacement by Fungicide-Resistant B. cinerea Strains.

    PubMed

    Plesken, Cecilia; Weber, Roland W S; Rupp, Sabrina; Leroch, Michaela; Hahn, Matthias

    2015-10-01

    Botrytis cinerea is one of the most important pathogens worldwide, causing gray mold on a large variety of crops. Botrytis pseudocinerea has been found previously to occur together with B. cinerea in low abundance in vineyards and strawberry fields. Here, we report B. pseudocinerea to be common and sometimes dominant over B. cinerea on several fruit and vegetable crops in Germany. On apples with calyx end rot and on oilseed rape, it was the major gray mold species. Abundance of B. pseudocinerea was often negatively correlated with fungicide treatments. On cultivated strawberries, it was frequently found in spring but was largely displaced by B. cinerea following fungicide applications. Whereas B. cinerea strains with multiple-fungicide resistance were common in these fields, B. pseudocinerea almost never developed resistance to any fungicide even though resistance mutations occurred at similar frequencies in both species under laboratory conditions. The absence of resistance to quinone outside inhibitors in B. pseudocinerea was correlated with an intron in cytB preventing the major G143A resistance mutation. Our work indicates that B. pseudocinerea has a wide host range similar to that of B. cinerea and that it can become an important gray mold pathogen on cultivated plants. PMID:26231644

  2. Botrytis pseudocinerea Is a Significant Pathogen of Several Crop Plants but Susceptible to Displacement by Fungicide-Resistant B. cinerea Strains

    PubMed Central

    Plesken, Cecilia; Weber, Roland W. S.; Rupp, Sabrina; Leroch, Michaela

    2015-01-01

    Botrytis cinerea is one of the most important pathogens worldwide, causing gray mold on a large variety of crops. Botrytis pseudocinerea has been found previously to occur together with B. cinerea in low abundance in vineyards and strawberry fields. Here, we report B. pseudocinerea to be common and sometimes dominant over B. cinerea on several fruit and vegetable crops in Germany. On apples with calyx end rot and on oilseed rape, it was the major gray mold species. Abundance of B. pseudocinerea was often negatively correlated with fungicide treatments. On cultivated strawberries, it was frequently found in spring but was largely displaced by B. cinerea following fungicide applications. Whereas B. cinerea strains with multiple-fungicide resistance were common in these fields, B. pseudocinerea almost never developed resistance to any fungicide even though resistance mutations occurred at similar frequencies in both species under laboratory conditions. The absence of resistance to quinone outside inhibitors in B. pseudocinerea was correlated with an intron in cytB preventing the major G143A resistance mutation. Our work indicates that B. pseudocinerea has a wide host range similar to that of B. cinerea and that it can become an important gray mold pathogen on cultivated plants. PMID:26231644

  3. RNA-seq pinpoints a Xanthomonas TAL-effector activated resistance gene in a large-crop genome

    PubMed Central

    Strauß, Tina; van Poecke, Remco M. P.; Strauß, Annett; Römer, Patrick; Minsavage, Gerald V.; Singh, Sylvia; Wolf, Christina; Strauß, Axel; Kim, Seungill; Lee, Hyun-Ah; Yeom, Seon-In; Parniske, Martin; Stall, Robert E.; Jones, Jeffrey B.; Choi, Doil; Prins, Marcel; Lahaye, Thomas

    2012-01-01

    Transcription activator-like effector (TALE) proteins of the plant pathogenic bacterial genus Xanthomonas bind to and transcriptionally activate host susceptibility genes, promoting disease. Plant immune systems have taken advantage of this mechanism by evolving TALE binding sites upstream of resistance (R) genes. For example, the pepper Bs3 and rice Xa27 genes are hypersensitive reaction plant R genes that are transcriptionally activated by corresponding TALEs. Both R genes have a hallmark expression pattern in which their transcripts are detectable only in the presence and not the absence of the corresponding TALE. By transcriptome profiling using next-generation sequencing (RNA-seq), we tested whether we could avoid laborious positional cloning for the isolation of TALE-induced R genes. In a proof-of-principle experiment, RNA-seq was used to identify a candidate for Bs4C, an R gene from pepper that mediates recognition of the Xanthomonas TALE protein AvrBs4. We identified one major Bs4C candidate transcript by RNA-seq that was expressed exclusively in the presence of AvrBs4. Complementation studies confirmed that the candidate corresponds to the Bs4C gene and that an AvrBs4 binding site in the Bs4C promoter directs its transcriptional activation. Comparison of Bs4C with a nonfunctional allele that is unable to recognize AvrBs4 revealed a 2-bp polymorphism within the TALE binding site of the Bs4C promoter. Bs4C encodes a structurally unique R protein and Bs4C-like genes that are present in many solanaceous genomes seem to be as tightly regulated as pepper Bs4C. These findings demonstrate that TALE-specific R genes can be cloned from large-genome crops with a highly efficient RNA-seq approach. PMID:23132937

  4. Effect of Modified Wheat Gluten on Boiling Resistance Capacity of Pork Meatballs.

    PubMed

    Wang, Kai-Qiang; Luo, Shui-Zhong; Zhong, Xi-Yang; Cai, Ke-Zhou; Cai, Jing; Jiang, Shao-Tong; Zheng, Zhi

    2016-02-01

    The effect of the modified wheat gluten (MWG) extender, prepared by alcalase-based hydrolysis and transglutaminase cross-linking, on meatballs was analyzed in this study. Here, we studied the effect of MWG addition on the boiling resistance capacity of pork meatballs (MB-MWG) at high temperature (100 °C) and increasing cooking time; meatballs with added soy protein isolates (MB-SPI) and raw wheat gluten (MB-WG) were used as references. The cooking loss, water-holding capacity (WHC), and textural properties of meatballs were investigated. The results revealed that MB-MWG showed lower cooking loss, which decreased by 49.16% compared to meatballs without added extenders when treated for 30 min. The WHC of MB-MWG significantly increased from 80.68% to 95.42%. The hardness, springiness, and chewiness (textural properties) of MB-MWG were also significantly increased by 97.05%, 6.68%, and 121.96%, respectively. The addition of MWG increased the cross-linking in meatballs during the cooking process, as indicated by the higher G'. SDS-PAGE indicated an obvious decrease in myosin heavy chain in MB-MWG cooked for 30 min at 100 °C, which was attributed to the interaction of myofibrillar proteins in pork meat with MWG. The nuclear magnetic resonance T2 relaxation time patterns indicated that MWG addition caused an increase in the bound water content, and decrease in the free water content, of meatballs. An analysis of the microstructures revealed that the MB-MWG formed the most regular and compact network. Therefore, MWG could be used as an ingredient to facilitate the processing of meat products. PMID:26766497

  5. Vancomycin modifies the expression of the agr system in multidrug-resistant Staphylococcus aureus clinical isolates

    PubMed Central

    Cázares-Domínguez, Vicenta; Ochoa, Sara A.; Cruz-Córdova, Ariadnna; Rodea, Gerardo E.; Escalona, Gerardo; Olivares, Alma L.; Olivares-Trejo, José de Jesús; Velázquez-Guadarrama, Norma; Xicohtencatl-Cortes, Juan

    2015-01-01

    Staphylococcus aureus is an opportunistic pathogen that colonizes human hosts and causes a wide variety of diseases. Two interacting regulatory systems called agr (accessory gene regulator) and sar (staphylococcal accessory regulator) are involved in the regulation of virulence factors. The aim of this study was to evaluate the effect of vancomycin on hld and spa gene expression during the exponential and post-exponential growth phases in multidrug-resistant (MDR) S. aureus. Methods: Antibiotic susceptibility was evaluated by the standard microdilution method. The phylogenetic profile was obtained by pulsed-field gel electrophoresis (PFGE). Polymorphisms of agr and SCCmec (staphylococcal cassette chromosome mec) were analyzed by multiplex polymerase chain reaction (PCR). The expression levels of hld and spa were analyzed by reverse transcription-PCR. An enzyme-linked immunosorbent assay (ELISA) was performed to detect protein A, and biofilm formation was analyzed via crystal violet staining. Results: In total, 60.60% (20/33) of S. aureus clinical isolates were MDR. Half (10/20) of the MDR S. aureus isolates were distributed in subcluster 10, with >90% similarity among them. In the isolates of this subcluster, a high prevalence (100%) for the agrII and the cassette SCCmec II polymorphisms was found. Our data showed significant increases in hld expression during the post-exponential phase in the presence and absence of vancomycin. Significant increases in spa expression, protein A production and biofilm formation were observed during the post-exponential phase when the MDR S. aureus isolates were challenged with vancomycin. Conclusion: The polymorphism agrII, which is associated with nosocomial isolates, was the most prevalent polymorphism in MDR S. aureus. Additionally, under our study conditions, vancomycin modified hld and spa expression in these clinical isolates. Therefore, vancomycin may regulate alternative systems that jointly participate in the regulation of

  6. Does Wheat Genetically Modified for Disease Resistance Affect Root-Colonizing Pseudomonads and Arbuscular Mycorrhizal Fungi?

    PubMed Central

    Foetzki, Andrea; Luginbühl, Carolin; Winzeler, Michael; Kneubühler, Yvan; Matasci, Caterina; Mascher-Frutschi, Fabio; Kalinina, Olena; Boller, Thomas; Keel, Christoph; Maurhofer, Monika

    2013-01-01

    This study aimed to evaluate the impact of genetically modified (GM) wheat with introduced pm3b mildew resistance transgene, on two types of root-colonizing microorganisms, namely pseudomonads and arbuscular mycorrhizal fungi (AMF). Our investigations were carried out in field trials over three field seasons and at two locations. Serial dilution in selective King's B medium and microscopy were used to assess the abundance of cultivable pseudomonads and AMF, respectively. We developed a denaturing gradient gel electrophoresis (DGGE) method to characterize the diversity of the pqqC gene, which is involved in Pseudomonas phosphate solubilization. A major result was that in the first field season Pseudomonas abundances and diversity on roots of GM pm3b lines, but also on non-GM sister lines were different from those of the parental lines and conventional wheat cultivars. This indicates a strong effect of the procedures by which these plants were created, as GM and sister lines were generated via tissue cultures and propagated in the greenhouse. Moreover, Pseudomonas population sizes and DGGE profiles varied considerably between individual GM lines with different genomic locations of the pm3b transgene. At individual time points, differences in Pseudomonas and AMF accumulation between GM and control lines were detected, but they were not consistent and much less pronounced than differences detected between young and old plants, different conventional wheat cultivars or at different locations and field seasons. Thus, we conclude that impacts of GM wheat on plant-beneficial root-colonizing microorganisms are minor and not of ecological importance. The cultivation-independent pqqC-DGGE approach proved to be a useful tool for monitoring the dynamics of Pseudomonas populations in a wheat field and even sensitive enough for detecting population responses to altered plant physiology. PMID:23372672

  7. [Genetically modified crops: promises and good intentions are not enough (refutation to Espinoza et aL 2004, Rev. Biol. Trop. 52 (3): 727-732)].

    PubMed

    García, Jaime E G

    2007-06-01

    The arguments presented by Espinoza et al. in their paper "Relationship of genetically modified crops with the environment and health of the Costa Rican human population" published in this journal (Rev. Biol. Trop. 52: 727-732, 2004) are questioned and refuted. The arguments are confronted with evidence offered by scientists and national and international independent organizations around the world (e.g. World Health Organization, Consumers International, Physicians and Scientists for Responsible Application of Science and Technology, International Union for Conservation of Nature and Natural Resources, the Council of the University of Costa Rica, and the Independent Science Panel) showing the current uncertainty and limitations of science in this area, as well as those of proposed and applied biosafety approaches. Environment, biodiversity and food security are so important and basic matters, that there is need of serious testing, particularly when promises seem to be based on environmentally dangerous ideas promoted half a century ago by the so called "green revolution". Debate should continue, based on a holistic analysis of facts and with ethical reasoning, avoiding emotional positions that can confuse virtual reality with reality. PMID:19069750

  8. Resistance evolution to the first generation of genetically modified Diabrotica-active Bt-maize events by western corn rootworm: management and monitoring considerations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Western corn rootworm (Diabrotica virgifera virgifera; WCR) is a major coleopteran maize pest in North America and the EU, and has traditionally been managed through crop rotation and broad-spectrum soil insecticides. Genetically modified (GM) Bt-maize offers an additional means of control against W...

  9. Genomic Modifiers of Natural Killer Cells, Immune Responsiveness and Lymphoid Tissue Remodeling Together Increase Host Resistance to Viral Infection

    PubMed Central

    Lee, Heather; Prince, Jessica; Stadnisky, Michael D.; Anderson, Monique; Nash, William; Rival, Claudia; Wei, Hairong; Gamache, Awndre; Farber, Charles R.; Tung, Kenneth; Brown, Michael G.

    2016-01-01

    The MHC class I Dk molecule supplies vital host resistance during murine cytomegalovirus (MCMV) infection. Natural killer (NK) cells expressing the Ly49G2 inhibitory receptor, which specifically binds Dk, are required to control viral spread. The extent of Dk-dependent host resistance, however, differs significantly amongst related strains of mice, C57L and MA/My. As a result, we predicted that relatively small-effect modifier genetic loci might together shape immune cell features, NK cell reactivity, and the host immune response to MCMV. A robust Dk-dependent genetic effect, however, has so far hindered attempts to identify additional host resistance factors. Thus, we applied genomic mapping strategies and multicolor flow cytometric analysis of immune cells in naive and virus-infected hosts to identify genetic modifiers of the host immune response to MCMV. We discovered and validated many quantitative trait loci (QTL); these were mapped to at least 19 positions on 16 chromosomes. Intriguingly, one newly discovered non-MHC locus (Cmv5) controlled splenic NK cell accrual, secondary lymphoid organ structure, and lymphoid follicle development during MCMV infection. We infer that Cmv5 aids host resistance to MCMV infection by expanding NK cells needed to preserve and protect essential tissue structural elements, to enhance lymphoid remodeling and to increase viral clearance in spleen. PMID:26845690

  10. Termite Resistance of Thermally-Modified Dendrocalamus asper (Schultes f.) Backer ex Heyne

    PubMed Central

    Manalo, Ronniel D.; Garcia, Carlos M.

    2012-01-01

    The effects of thermal modification on the resistance of Dendrocalamus asper against Microcerotermes losbañosensis were investigated after exposure to virgin coconut oil at 140–200 °C for 30–120 min. The results showed that heat treatment significantly improved bamboo’s resistance to termites based on mass losses and visual observations. The enhancement was highest at 200 °C. Prolonged treatment had a positive effect on the resistance at lower temperatures only. PMID:26466531

  11. Corrosion resistance of enamel coating modified by calcium silicate and sand particle for steel reinforcement in concrete

    NASA Astrophysics Data System (ADS)

    Tang, Fujian

    Porcelain enamel has stable chemical property in harsh environments such as high temperature, acid and alkaline, and it can also chemically react with substrate reinforcing steel resulting in improved adherence strength. In this study, the corrosion resistances of enamel coating modified by calcium silicate and sand particles, which are designed for improved bond strength with surrounding concrete, were investigated in 3.5 wt% NaCl solution. It consists of two papers that describe the results of the study. The first paper investigates the corrosion behavior of enamel coating modified by calcium silicate applied to reinforcing steel bar in 3.5 wt% NaCl solution by OCP, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The coatings include a pure enamel, a mixed enamel that consists of 50% pure enamel and 50% calcium silicate by weight, and a double enamel that has an inner pure enamel layer and an outer mixed enamel layer. Electrochemical tests demonstrates that both pure and double enamel coatings can significantly improve corrosion resistance, while the mixed enamel coating offers very little protection due to connected channels. The second paper is focused on the electrochemical characteristics of enamel coating modified by sand particle applied to reinforcing steel bar in 3.5 wt% NaCl solution by EIS. Six percentages by weight are considered including 5%, 10%, 20%, 30%, 50%, and 70%. Results reveal that addition of sand particle does not affect its corrosion resistance significantly. Most of the sand particles can wet very well with enamel body, while some have a weak zone which is induced during the cooling stage due to different coefficient of thermal expansion. Therefore, quality control of sand particle is the key factor to improve its corrosion resistance.

  12. Modified live Edwardsiella ictaluri vaccine, AQUAVAC-ESC, lacks multidrug resistance plasmids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasmid mediated antibiotic resistance was first discovered in Edwardsiella ictaluri in the early 1990’s, and in 2007 an E. ictaluri isolate harboring an IncA/C plasmid was recovered from a moribund channel catfish infected with the bacterium. Due to the identification of multidrug resistance plasm...

  13. Modified porous silica antireflective coatings with laser damage resistance for Ti:sapphire

    NASA Astrophysics Data System (ADS)

    Jia, Qiaoying; Li, Haiyuan; Liu, Ruijun; Tang, Yongxing; Jiang, Zhonghong

    2005-04-01

    Porous SiO2 antireflective (AR) coatings are prepared from the colloidal silica solution modified with methyltriethoxysilane (MTES) based on the sol-gel route. The viscosity of modified silica suspensions changes but their stability keeps when MTES is introduced. The refractive indices of modified coatings vary little after bake treatment from 100 to 150 Celsius. The modified silica coatings on Ti:sapphire crystal, owning good homogeneity, display prominent antireflective effect within the laser output waveband (750-850 nm) of Ti:sapphire lasers, with average transmission above 98.6%, and own laser induced damage thresholds (LIDTs) of more than 2.2 J/cm2 at 800 nm with the pulse duration of 300 ps.

  14. Long-term Impact of Childhood Adiposity on Adult Metabolic Syndrome Is Modified by Insulin Resistance: The Bogalusa Heart Study

    PubMed Central

    Zhang, Huijie; Zhang, Tao; Li, Shengxu; Li, Ying; Hussain, Azad; Fernandez, Camilo; Harville, Emily; Bazzano, Lydia A.; He, Jiang; Chen, Wei

    2015-01-01

    Childhood adiposity and insulin resistance are well-known risk factors for adult metabolic syndrome (MetS). This study aims to examine whether the association between childhood adiposity and adult MetS is modified by insulin resistance. The cohort consisted of 1,593 black and white subjects, aged 19–50 years at follow-up, who were examined 19 years apart on average as children and adults for MetS variables. The prevalence of adult MetS was compared between the insulin-sensitive obesity and insulin-resistant obesity groups in childhood. Adult MetS prevalence was higher in the insulin-resistant obesity group than in the insulin-sensitive obesity group (34.9% vs. 24.3%, p = 0.008). In multivariable logistic regression analyses adjusted for age, race, gender, and follow-up years, individuals with insulin-resistant obesity in childhood were 1.7 times (p = 0.011) more likely to have MetS 19 years later on average than those with insulin-sensitive obesity in childhood. Odds ratio did not differ significantly between blacks and whites (p = 0.724). ORs for the association of childhood BMI with adult MetS significantly increased with increasing tertiles of childhood HOMA (p < 0.001 for trend). These findings suggest that insulin resistance amplifies the association between childhood adiposity and adult MetS and underscore the importance of preventing both adiposity and insulin resistance in early life. PMID:26640243

  15. Monitoring the agricultural landscape for insect resistance

    NASA Astrophysics Data System (ADS)

    Casas, Joseph; Glaser, J. A.; Copenhaver, Ken

    Farmers in 25 countries on six continents are using plant biotechnology to solve difficult crop production challenges and conserve the environment. In fact, 13.3 million farmers, which include 90 percent of the farming in developing countries, choose to plant biotech crops. Over the past decade, farmers increased area planted in genetically modified (GM) crops by more than 10 percent each year, thus increasing their farm income by more than 44 billion US dollars (1996-2007), and achieved economic, environmental and social benefits in crops such as soybeans, canola, corn and cotton. To date, total acres of biotech crops harvested exceed more than 2 billion with a proven 13-year history of safe use. Over the next decade, expanded adoption combined with current research on 57 crops in 63 countries will broaden the advantages of genetically modified foods for growers, consumers and the environment. Genetically modified (GM) crops with the ability to produce toxins lethal to specific insect pests are covering a larger percentage of the agricultural landscape every year. The United States department of Agriculture (USDA) estimated that 63 percent of corn and 65 percent of cotton contained these specific genetic traits in 2009. The toxins could protect billions of dollars of loss from insect damage for crops valued at greater than 165 billion US dollars in 2008. The stable and efficient production of these crops has taken on even more importance in recent years with their use, not only as a food source, but now also a source of fuel. It is in the best interest of the United States Environmental Protection Agency (USEPA) to ensure the continued efficacy of toxin producing GM crops as their use reduces pesticides harmful to humans and animals. However, population genetics models have indicated the risk of insect pests developing resistance to these toxins if a high percentage of acreage is grown in these crops. The USEPA is developing methods to monitor the agricultural

  16. Protein resistance of surfaces modified with oligo(ethylene glycol) aryl diazonium derivatives.

    PubMed

    Fairman, Callie; Ginges, Joshua Z; Lowe, Stuart B; Gooding, J Justin

    2013-07-22

    Anti-fouling surfaces are of great importance for reducing background interference in biosensor signals. Oligo(ethylene glycol) (OEG) moieties are commonly used to confer protein resistance on gold, silicon and carbon surfaces. Herein, we report the modification of surfaces using electrochemical deposition of OEG aryl diazonium salts. Using electrochemical and contact angle measurements, the ligand packing density is found to be loose, which supports the findings of the fluorescent protein labelling that aryl diazonium OEGs confer resistance to nonspecific adsorption of proteins albeit lower than alkane thiol-terminated OEGs. In addition to protein resistance, aryl diazonium attachment chemistry results in stable modification. In common with OEG species on gold electrodes, OEGs with distal hydroxyl moieties do confer superior protein resistance to those with a distal methoxy group. This is especially the case for longer derivatives where superior coiling of the OEG chains is possible. PMID:23650106

  17. Using vegetative index and modified derivative for early detection of soybean plant injury from glyphosate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate is a non-selective, systemic herbicide highly toxic to sensitive plant species, and its use has seen a significant increase due to the increased adoption of genetically modified glyphosate-resistant crops since the mid-1990s. Glyphosate application for weed control in glyphosate-resistant...

  18. Epitaxial Growth of High-Resistivity CdTe Thick Films Grown Using a Modified Close Space Sublimation Method

    NASA Astrophysics Data System (ADS)

    Jiang, Quanzhong; Brinkman, Andy W.; Veeramani, Perumal; Sellin, Paul. J.

    2010-02-01

    This paper reports the growth of high-resistivity CdTe thick epitaxial films of single crystal nature using a modified close space sublimation method (MCSS) in a Te-rich environment. We propose that the high Te2 partial pressure results in an increased concentration of TeCd antisites acting as deep donors to produce the high-resistivity CdTe, as well as improved quality of thick films. This is in agreement with the deep-donor model introduced by Fiderele et al. [Cryst. Res. Technol. 38 (2003) 588]. The thick films have a µeτe value in the order 10-4 cm2 V-1 and as expected, the TeCd antisites appeared not to act as electron traps.

  19. Corrosion Resistance of Electrogalvanized Steel Coated with PEG-Modified Ceria Layers in Chloride and Sulfate Media

    NASA Astrophysics Data System (ADS)

    Hamlaoui, Y.; Boudellioua, H.; Tifouti, L.; Pedraza, F.

    2015-12-01

    A comparative study of the corrosion resistance and corrosion products formed on polyethylene glycol (PEG)-modified and untreated cerium oxide-based coatings onto electrogalvanized steel substrate in chloride and sulfate media is presented. The corrosion monitoring was investigated through electrochemical impedance spectroscopy and d.c. polarization measurements. The corrosion products were analyzed by x-ray diffraction and Raman spectroscopy. In the absence of PEG, the corrosion resistance impaired by the cerium oxide coatings was lost after short immersion times in the chloride medium but not in the sulfate one. The cracks in the cerium oxide coatings were found to be responsible for their fast degradation with the formation of zinc hydroxides. However, the incorporation of PEG to the cerium oxide deposits displayed a perfect stability in both media, due to the disappearance of cracks in the coatings and to the formation of stable corrosion products.

  20. Biofouling-resistant ceragenin-modified materials and structures for water treatment

    DOEpatents

    Hibbs, Michael; Altman, Susan J.; Jones, Howland D. T.; Savage, Paul B.

    2013-09-10

    This invention relates to methods for chemically grafting and attaching ceragenin molecules to polymer substrates; methods for synthesizing ceragenin-containing copolymers; methods for making ceragenin-modified water treatment membranes and spacers; and methods of treating contaminated water using ceragenin-modified treatment membranes and spacers. Ceragenins are synthetically produced antimicrobial peptide mimics that display broad-spectrum bactericidal activity. Alkene-functionalized ceragenins (e.g., acrylamide-functionalized ceragenins) can be attached to polyamide reverse osmosis membranes using amine-linking, amide-linking, UV-grafting, or silane-coating methods. In addition, silane-functionalized ceragenins can be directly attached to polymer surfaces that have free hydroxyls.

  1. Listeria monocytogenes Is Resistant to Lysozyme through the Regulation, Not the Acquisition, of Cell Wall-Modifying Enzymes

    PubMed Central

    Burke, Thomas P.; Loukitcheva, Anastasia; Zemansky, Jason; Wheeler, Richard; Boneca, Ivo G.

    2014-01-01

    Listeria monocytogenes is a Gram-positive facultative intracellular pathogen that is highly resistant to lysozyme, a ubiquitous enzyme of the innate immune system that degrades cell wall peptidoglycan. Two peptidoglycan-modifying enzymes, PgdA and OatA, confer lysozyme resistance on L. monocytogenes; however, these enzymes are also conserved among lysozyme-sensitive nonpathogens. We sought to identify additional factors responsible for lysozyme resistance in L. monocytogenes. A forward genetic screen for lysozyme-sensitive mutants led to the identification of 174 transposon insertion mutations that mapped to 13 individual genes. Four mutants were killed exclusively by lysozyme and not other cell wall-targeting molecules, including the peptidoglycan deacetylase encoded by pgdA, the putative carboxypeptidase encoded by pbpX, the orphan response regulator encoded by degU, and the highly abundant noncoding RNA encoded by rli31. Both degU and rli31 mutants had reduced expression of pbpX and pgdA, yet DegU and Rli31 did not regulate each other. Since pbpX and pgdA are also present in lysozyme-sensitive bacteria, this suggested that the acquisition of novel enzymes was not responsible for lysozyme resistance, but rather, the regulation of conserved enzymes by DegU and Rli31 conferred high lysozyme resistance. Each lysozyme-sensitive mutant exhibited attenuated virulence in mice, and a time course of infection revealed that the most lysozyme-sensitive strain was killed within 30 min of intravenous infection, a phenotype that was recapitulated in purified blood. Collectively, these data indicate that the genes required for lysozyme resistance are highly upregulated determinants of L. monocytogenes pathogenesis that are required for avoiding the enzymatic activity of lysozyme in the blood. PMID:25157076

  2. Expression of chloroperoxidase from Pseudomonas pyrrocinia in tobacco plastids for fungal resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    While genetic improvement of susceptible crop species may enhance resistance to microbial pathogens and facilitate reduced pesticide load, the possibility for transmission of novel genes to wild relatives has hampered acceptance of genetically modified (GM) crops in some markets. Chloroplast transf...

  3. Gene Amplification Is A Mechanism For Rapid Weed Evolution To Herbicide Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The herbicide glyphosate became widely used in the U.S. and other parts of the world following the introduction of glyphosate-resistant crops. These crops were created by introduction of a modified 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene, the herbicide target site. Increased use of ...

  4. HOX genes: Major actors in resistance to selective endocrine response modifiers.

    PubMed

    Jin, Kideok; Sukumar, Saraswati

    2016-04-01

    Long term treatment with therapies aimed at blocking the estrogen- (ER) or androgen receptor (AR) action often leads to the development of resistance to selective modulators of the estrogen receptor (SERMs) in ERα-positive breast cancer, or of the androgen receptor (SARMs) in AR-positive prostate cancer. Many underlying molecular events that confer resistance are known, but a unifying theme is yet to be revealed. Receptor tyrosine kinases (RTKs) such EGFR, ERBB2 and IGF1R are major mediators that can directly alter cellular response to the SERM, tamoxifen, but the mechanisms underlying increased expression of RTKs are not clear. A number of HOX genes and microRNAs and non-coding RNAs residing in the HOX cluster, have been identified as important independent predictors of endocrine resistant breast cancer. Recently, convincing evidence has accumulated that several members belonging to the four different HOX clusters contribute to endocrine therapy resistant breast cancer, but the mechanisms remain obscure. In this article, we have reviewed recent progress in understanding of the functioning of HOX genes and regulation of their expression by hormones. We also discuss, in particular, the contributions of several members of the HOX gene family to endocrine resistant breast cancer. PMID:26803986

  5. The food and environmental safety of Bt crops

    PubMed Central

    Koch, Michael S.; Ward, Jason M.; Levine, Steven L.; Baum, James A.; Vicini, John L.; Hammond, Bruce G.

    2015-01-01

    Bacillus thuringiensis (Bt) microbial pesticides have a 50-year history of safety in agriculture. Cry proteins are among the active insecticidal ingredients in these pesticides, and genes coding for Cry proteins have been introduced into agricultural crops using modern biotechnology. The Cry gene sequences are often modified to enable effective expression in planta and several Cry proteins have been modified to increase biological activity against the target pest(s). Additionally, the domains of different but structurally conserved Cry proteins can be combined to produce chimeric proteins with enhanced insecticidal properties. Environmental studies are performed and include invertebrates, mammals, and avian species. Mammalian studies used to support the food and feed safety assessment are also used to support the wild mammal assessment. In addition to the NTO assessment, the environmental assessment includes a comparative assessment between the Bt crop and the appropriate conventional control that is genetically similar but lacks the introduced trait to address unintended effects. Specific phenotypic, agronomic, and ecological characteristics are measured in the Bt crop and the conventional control to evaluate whether the introduction of the insect resistance has resulted in any changes that might cause ecological harm in terms of altered weed characteristics, susceptibility to pests, or adverse environmental impact. Additionally, environmental interaction data are collected in field experiments for Bt crop to evaluate potential adverse effects. Further to the agronomic and phenotypic evaluation, potential movement of transgenes from a genetically modified crop plants into wild relatives is assessed for a new pest resistance gene in a new crop. This review summarizes the evidence for safety of crops containing Cry proteins for humans, livestock, and other non-target organisms. PMID:25972882

  6. The food and environmental safety of Bt crops.

    PubMed

    Koch, Michael S; Ward, Jason M; Levine, Steven L; Baum, James A; Vicini, John L; Hammond, Bruce G

    2015-01-01

    Bacillus thuringiensis (Bt) microbial pesticides have a 50-year history of safety in agriculture. Cry proteins are among the active insecticidal ingredients in these pesticides, and genes coding for Cry proteins have been introduced into agricultural crops using modern biotechnology. The Cry gene sequences are often modified to enable effective expression in planta and several Cry proteins have been modified to increase biological activity against the target pest(s). Additionally, the domains of different but structurally conserved Cry proteins can be combined to produce chimeric proteins with enhanced insecticidal properties. Environmental studies are performed and include invertebrates, mammals, and avian species. Mammalian studies used to support the food and feed safety assessment are also used to support the wild mammal assessment. In addition to the NTO assessment, the environmental assessment includes a comparative assessment between the Bt crop and the appropriate conventional control that is genetically similar but lacks the introduced trait to address unintended effects. Specific phenotypic, agronomic, and ecological characteristics are measured in the Bt crop and the conventional control to evaluate whether the introduction of the insect resistance has resulted in any changes that might cause ecological harm in terms of altered weed characteristics, susceptibility to pests, or adverse environmental impact. Additionally, environmental interaction data are collected in field experiments for Bt crop to evaluate potential adverse effects. Further to the agronomic and phenotypic evaluation, potential movement of transgenes from a genetically modified crop plants into wild relatives is assessed for a new pest resistance gene in a new crop. This review summarizes the evidence for safety of crops containing Cry proteins for humans, livestock, and other non-target organisms. PMID:25972882

  7. High level of resistance to aztreonam and ticarcillin in Pseudomonas aeruginosa isolated from soil of different crops in Brazil.

    PubMed

    Pitondo-Silva, André; Martins, Vinicius Vicente; Fernandes, Ana Flavia Tonelli; Stehling, Eliana Guedes

    2014-03-01

    Pseudomonas aeruginosa can be found in water, soil, plants and, human and animal fecal samples. It is an important nosocomial pathogenic agent characterized by an intrinsic resistance to multiple antimicrobial agents and the ability to develop high-level (acquired) multidrug resistance through some mechanisms, among them, by the acquisition of plasmids and integrons, which are mobile genetic elements. In this study, 40 isolates from Brazilian soil were analyzed for antibiotic resistance, presence of integrons and plasmidial profile. The results demonstrated that the vast majority of the isolates have shown resistance for aztreonam (92.5%, n=37) and ticarcillin (85%, n=34), four isolates presented plasmids and eight isolates possess the class 1 integron. These results demonstrated that environmental isolates of P. aeruginosa possess surprising antibiotic resistance profile to aztreonam and ticarcillin, two antimicrobial agents for clinical treatment of cystic fibrosis patients and other infections occurred by P. aeruginosa. PMID:24369293

  8. A Modified Time-Delay Addition Method to Extract Resistive Leakage Current of MOSA

    NASA Astrophysics Data System (ADS)

    Khodsuz, Masume; Mirzaie, Mohammad

    2015-06-01

    Metal oxide surge arresters are one of the most important equipment for power system protection against switching and lightning over-voltages. High-energy stresses and environmental features are the main factors which degrade surge arresters. In order to verify surge arresters good condition, their monitoring is necessary. The majority of surge arrester monitoring techniques is based on total leakage current decomposition of their capacitive and resistive components. This paper introduces a new approach based on time-delay addition method to extract the resistive current from the total leakage current without measuring voltage signal. Surge arrester model for calculating leakage current has been performed in ATP-EMTP. In addition, the signal processing has been done using MATLAB software. To show the accuracy of the proposed method, experimental tests have been performed to extract resistive leakage current by the proposed method.

  9. Copper modified austenitic stainless steel alloys with improved high temperature creep resistance

    DOEpatents

    Swindeman, R.W.; Maziasz, P.J.

    1987-04-28

    An improved austenitic stainless steel that incorporates copper into a base Fe-Ni-Cr alloy having minor alloying substituents of Mo, Mn, Si, T, Nb, V, C, N, P, B which exhibits significant improvement in high temperature creep resistance over previous steels. 3 figs.

  10. Genome-wide analysis of NBS-encoding disease resistance genes in Cucumis sativus and phylogenetic study of NBS-encoding genes in Cucurbitaceae crops

    PubMed Central

    2013-01-01

    Background Plant nucleotide-binding site (NBS)-leucine-rich repeat (LRR) proteins encoded by resistance genes play an important role in the responses of plants to various pathogens, including viruses, bacteria, fungi, and nematodes. In this study, a comprehensive analysis of NBS-encoding genes within the whole cucumber genome was performed, and the phylogenetic relationships of NBS-encoding resistance gene homologues (RGHs) belonging to six species in five genera of Cucurbitaceae crops were compared. Results Cucumber has relatively few NBS-encoding genes. Nevertheless, cucumber maintains genes belonging to both Toll/interleukine-1 receptor (TIR) and CC (coiled-coil) families. Eight commonly conserved motifs have been established in these two families which support the grouping into TIR and CC families. Moreover, three additional conserved motifs, namely, CNBS-1, CNBS-2 and TNBS-1, have been identified in sequences from CC and TIR families. Analyses of exon/intron configurations revealed that some intron loss or gain events occurred during the structural evolution between the two families. Phylogenetic analyses revealed that gene duplication, sequence divergence, and gene loss were proposed as the major modes of evolution of NBS-encoding genes in Cucurbitaceae species. Compared with NBS-encoding sequences from the Arabidopsis thaliana genome, the remaining seven TIR familes of NBS proteins and RGHs from Cucurbitaceae species have been shown to be phylogenetically distinct from the TIR family of NBS-encoding genes in Arabidopsis, except for two subfamilies (TIR4 and TIR9). On the other hand, in the CC-NBS family, they grouped closely with the CC family of NBS-encoding genes in Arabidopsis. Thus, the NBS-encoding genes in Cucurbitaceae crops are shown to be ancient, and NBS-encoding gene expansions (especially the TIR family) may have occurred before the divergence of Cucurbitaceae and Arabidopsis. Conclusion The results of this paper will provide a genomic framework

  11. Modified CHROMagar Acinetobacter Medium for Direct Detection of Multidrug-Resistant Acinetobacter Strains in Nasal and Rectal Swab Samples

    PubMed Central

    Lee, Jacob; Kim, Taek-Kyung; Park, Min-Jeong; Kim, Han-Sung; Kim, Jae-Seok

    2013-01-01

    This study aimed to investigate whether CHROMagar Acinetobacter medium (CHROMagar, France) in combination with an antimicrobial supplement (modified CHROMagar Acinetobacter; CHROMagar, France) can be used for detecting and isolating multidrug-resistant Acinetobacter species (MRA) in nasal and rectal surveillance cultures. Nasal and rectal swab samples were collected from patients in an intensive care unit at a teaching hospital. The samples were used to inoculate modified CHROMagar Acinetobacter plates, which were examined after 24 and 48 hr of incubation at 37℃. Their susceptibility against the antimicrobial agents meropenem, imipenem, ciprofloxacin, and amikacin was analyzed using the Etest (bioMerieux, France). A total of 406 paired samples (406 nasal swabs and 406 rectal swabs) were obtained from 226 patients, and 120 samples (28 nasal and 28 rectal cultures, 47 nasal cultures only, and 17 rectal cultures only) yielded MRA. Seventy-five MRA isolates (18.5%) were recovered from the 406 nasal samples, and 45 MRA isolates (11.1%) were recovered from the 406 rectal samples. Of the 120 MRA isolates, 3 (2.5%) were detected only after 48 hr of incubation. The use of modified CHROMagar Acinetobacter together with nasal and rectal swabs and 1-day incubation is an effective surveillance tool for detecting MRA colonization. PMID:23667846

  12. The prevalence of aminoglycoside-modifying enzyme and virulence genes among enterococci with high-level aminoglycoside resistance in Inner Mongolia, China.

    PubMed

    Niu, Haiying; Yu, Hui; Hu, Tangping; Tian, Gailin; Zhang, Lixia; Guo, Xiang; Hu, Hai; Wang, Zhanli

    2016-01-01

    This study highlights the prevalence of aminoglycoside-modifying enzyme genes and virulence determinants among clinical enterococci with high-level aminoglycoside resistance in Inner Mongolia, China. Screening for high-level aminoglycoside resistance against 117 enterococcal clinical isolates was performed using the agar-screening method. Out of the 117 enterococcal isolates, 46 were selected for further detection and determination of the distribution of aminoglycoside-modifying enzyme-encoding genes and virulence determinants using polymerase chain reaction -based methods. Enterococcus faecium and Enterococcus faecalis were identified as the species of greatest clinical importance. The aac(6')-Ie-aph(2″)-Ia and ant(6')-Ia genes were found to be the most common aminoglycoside-modifying enzyme genes among high-level gentamicin resistance and high-level streptomycin resistance isolates, respectively. Moreover, gelE was the most common virulence gene among high-level aminoglycoside resistance isolates. Compared to Enterococcus faecium, Enterococcus faecalis harbored multiple virulence determinants. The results further indicated no correlation between aminoglycoside-modifying enzyme gene profiles and the distribution of virulence genes among the enterococcal isolates with high-level gentamicin resistance or high-level streptomycin resistance evaluated in our study. PMID:27268115

  13. Cetuximab-modified mesoporous silica nano-medicine specifically targets EGFR-mutant lung cancer and overcomes drug resistance.

    PubMed

    Wang, Yuetong; Huang, Hsin-Yi; Yang, Liu; Zhang, Zhanxia; Ji, Hongbin

    2016-01-01

    Drug resistance to tyrosine kinase inhibitor (TKI) is the main obstacle for efficient treatment of epidermal growth factor receptor (EGFR)-mutant lung cancer patients. Here we design a cetuximab-capped mesoporous silica nanoparticle (MP-SiO2 NP) as the drug carrier to specifically target EGFR-mutant lung cancer cells and efficiently release loaded drugs including doxorubicin and gefitinib. This innovative nano-medicine can specifically target lung cancer cells with high EGFR expression rather than those with low EGFR level. Treatment of a gefitinib-resistant cell line derived from PC9 cell (PC9-DR) with the gefitinib-loaded cetuximab-capped MP-SiO2 NP showed a significant inhibition of cell growth. Moreover, this nano-medicine successfully suppressed the progression of PC9-DR xenograft tumors. This tumor suppression was due to the endocytosis of large amount of nano-medicine and the effective gefitinib release induced by high glutathione (GSH) level in PC9-DR cells. Collectively, our study provides a novel approach to overcome EGFR-TKI resistance using cetuximab modified MP-SiO2 NP, which holds strong potential for effective management of EGFR-mutant lung cancer. PMID:27151505

  14. Cetuximab-modified mesoporous silica nano-medicine specifically targets EGFR-mutant lung cancer and overcomes drug resistance

    PubMed Central

    Wang, Yuetong; Huang, Hsin-Yi; Yang, Liu; Zhang, Zhanxia; Ji, Hongbin

    2016-01-01

    Drug resistance to tyrosine kinase inhibitor (TKI) is the main obstacle for efficient treatment of epidermal growth factor receptor (EGFR)-mutant lung cancer patients. Here we design a cetuximab-capped mesoporous silica nanoparticle (MP-SiO2 NP) as the drug carrier to specifically target EGFR-mutant lung cancer cells and efficiently release loaded drugs including doxorubicin and gefitinib. This innovative nano-medicine can specifically target lung cancer cells with high EGFR expression rather than those with low EGFR level. Treatment of a gefitinib-resistant cell line derived from PC9 cell (PC9-DR) with the gefitinib-loaded cetuximab-capped MP-SiO2 NP showed a significant inhibition of cell growth. Moreover, this nano-medicine successfully suppressed the progression of PC9-DR xenograft tumors. This tumor suppression was due to the endocytosis of large amount of nano-medicine and the effective gefitinib release induced by high glutathione (GSH) level in PC9-DR cells. Collectively, our study provides a novel approach to overcome EGFR-TKI resistance using cetuximab modified MP-SiO2 NP, which holds strong potential for effective management of EGFR-mutant lung cancer. PMID:27151505

  15. Cross-Contamination of Residual Emerging Contaminants and Antibiotic Resistant Bacteria in Lettuce Crops and Soil Irrigated with Wastewater Treated by Sunlight/H2O2.

    PubMed

    Ferro, Giovanna; Polo-López, María I; Martínez-Piernas, Ana B; Fernández-Ibáñez, Pilar; Agüera, Ana; Rizzo, Luigi

    2015-09-15

    The sunlight/H2O2 process has recently been considered as a sustainable alternative option compared to other solar driven advanced oxidation processes (AOPs) in advanced treatment of municipal wastewater (WW) to be reused for crop irrigation. Accordingly, in this study sunlight/H2O2 was used as disinfection/oxidation treatment for urban WW treatment plant effluent in a compound parabolic collector photoreactor to assess subsequent cross-contamination of lettuce and soil by contaminants of emerging concern (CECs) (determined by QuEChERS extraction and LC-QqLIT-MS/MS analysis) and antibiotic resistant (AR) bacteria after irrigation with treated WW. Three CECs (carbamazepine (CBZ), flumequine (FLU), and thiabendazole (TBZ) at 100 μg L(-1)) and two AR bacterial strains (E. coli and E. faecalis, at 10(5) CFU mL(-1)) were spiked in real WW. A detection limit (DL) of 2 CFU mL(-1) was reached after 120 min of solar exposure for AR E. coli, while AR E. faecalis was more resistant to the disinfection process (240 min to reach DL). CBZ and TBZ were poorly removed after 90 min (12% and 50%, respectively) compared to FLU (94%). Lettuce was irrigated with treated WW for 5 weeks. CBZ and TBZ were accumulated in soil up to 472 ng g(-1) and 256 ng g(-1) and up-taken by lettuce up to 109 and 18 ng g(-1), respectively, when 90 min treated WW was used for irrigation; whereas no bacteria contamination was observed when the bacterial density in treated WW was below the DL. A proper treatment time (>90 min) should be guaranteed in order to avoid the transfer of pathogens from disinfected WW to irrigated crops and soil. PMID:26280108

  16. Dramatic reduction of crop-to-crop gene flow within a short distance from transgenic rice fields.

    PubMed

    Rong, Jun; Lu, Bao-Rong; Song, Zhiping; Su, Jun; Snow, Allison A; Zhang, Xinsheng; Sun, Shuguang; Chen, Rui; Wang, Feng

    2007-01-01

    Genetically modified (GM) rice with enhanced agronomic traits and pharmaceutical uses are ready for widespread adoption. Little is known about isolation requirements for achieving stringent transgene confinement in rice. To investigate the extent of pollen-mediated crop-to-crop transgene flow, we conducted a field experiment with four plot-size treatments of adjacent GM and nonGM rice (Oryza sativa) in China. Three insect-resistant GM rice (Bt/CpTI) and nonGM isogenic lines were used in the study. The hygromycin-resistance transgene (hpt) marker was used to screen seeds from the nonGM rice rows at different distance intervals from GM rice plots. Based on the examination of > 2.1 million germinated seeds, we found a dramatic reduction in transgene frequencies with increasing distance from the GM crop, ranging from c. 0.28% at 0.2 m to < 0.01% at 6.2 m. In addition, different plot size did not significantly affect the frequencies of gene flow. In conclusion, pollen-mediated crop-to-crop transgene flow in rice can be maintained at negligible levels with short spatial isolation. The model can also be applied to other crops with self- and wind-pollination. PMID:17204081

  17. Pollen-mediated movement of herbicide resistance between commercial canola fields.

    PubMed

    Rieger, Mary A; Lamond, Michael; Preston, Christopher; Powles, Stephen B; Roush, Richard T

    2002-06-28

    There is considerable public and scientific debate for and against genetically modified (GM) crops. One of the first GM crops, Brassica napus (oilseed rape or canola) is now widely grown in North America, with proposed commercial release into Australia and Europe. Among concerns of opponents to these crops are claims that pollen movement will cause unacceptable levels of gene flow from GM to non-GM crops or to related weedy species, resulting in genetic pollution of the environment. Therefore, quantifying pollen-mediated gene flow is vital for assessing the environmental impact of GM crops. This study quantifies at a landscape level the gene flow that occurs from herbicide-resistant canola crops to nearby crops not containing herbicide resistance genes. PMID:12089441

  18. Designing of putative siRNA against geminiviral suppressors of RNAi to develop geminivirus-resistant papaya crop.

    PubMed

    Saxena, Sangeeta; Kesharwani, Rupesh K; Singh, Vinayak; Singh, Sarita

    2013-01-01

    Geminiviruses are single-stranded circular DNA viruses causing leaf curl disease in papaya crop. Post-Transcriptional Gene Silencing (PTGS), also known as RNAi, acts as a natural antiviral defence mechanism and plays a role in genome maintenance and development in plants. PTGS suppression by viruses makes the plant RNA silencing machinery inefficient. Three geminiviral genes namely AV2, AC2 and AC4 are found to play the role in suppression of RNA silencing. siRNA degrades the target mRNA in a homology-dependent manner. In-silico designing of siRNA against these three genes of geminiviruses infecting Carica papaya was done using bioinformatics tools. This strategy may provide PTGS by specifically targeting the viral genes involved in suppression of plant RNA silencing machinery. PMID:23207994

  19. Multifunctional hyaluronic acid modified graphene oxide loaded with mitoxantrone for overcoming drug resistance in cancer

    NASA Astrophysics Data System (ADS)

    Hou, Lin; Feng, Qianhua; Wang, Yating; Yang, Xiaomin; Ren, Junxiao; Shi, Yuyang; Shan, Xiaoning; Yuan, Yujie; Wang, Yongchao; Zhang, Zhenzhong

    2016-01-01

    Multifunctional nanosheets (HA-GO/Pluronic) with targeted chemo-photothermal properties were successfully developed for controlled delivery of mitoxantrone (MIT) to overcome multidrug resistance (MDR). In vitro release profiles displayed that both an acidic environment and a NIR laser could trigger and accelerate the release of a drug, which ensured nanosheets were stable in blood circulation and released MIT within tumor cells under laser irradiation. HA-GO/Pluronic nanosheets were taken up into MCF-7/ADR cells via receptor-mediated endocytosis, which further facilitated escapement of P-gp efflux. Compared with MIT solution, MIT/HA-GO/Pluronic showed greater cytotoxicity and increase in cellular MIT accumulation in MCF-7/ADR cells. Cell apoptosis and cell cycle arrest studies also revealed that MIT/HA-GO/Pluronic was more potent than MIT/GO/Pluronic and MIT solution. The anticancer efficacy in vivo was evaluated in MCF-7 and MCF-7/ADR-bearing mice, and inhibition of tumors by MIT/HA-GO/Pluronic with NIR laser irradiation was the most effective among all MIT formulations. In summary, the MIT/HA-GO/Pluronic system had striking functions such as P-gp reversible inhibitor and anticancer efficacy, and could present a promising platform for drug-resistant cancer treatment.

  20. Erwinia amylovora modifies phenolic profiles of susceptible and resistant apple through its type III secretion system.

    PubMed

    Pontais, Isabelle; Treutter, Dieter; Paulin, Jean-Pierre; Brisset, Marie-Noëlle

    2008-03-01

    Fire blight is a disease affecting Maloideae caused by the necrogenic bacterium Erwinia amylovora, which requires the type III protein secretion system (TTSS) for pathogenicity. Profiles of methanol-extractable leaf phenolics of two apple (Malus x domestica) genotypes with contrasting susceptibility to this disease were analyzed by HPLC after infection. Some qualitative differences were recorded between the constitutive compositions of the two genotypes but in both of them dihydrochalcones accounted for more than 90% of total phenolics. Principal component analysis separated leaves inoculated with a virulent wild-type strain from those inoculated with a non-pathogenic TTSS-defective mutant or with water. The changes in levels of the various groups of phenolics in response to the virulent bacterium were similar between the two genotypes, with a significant decrease of dihydrochalcones and a significant increase of hydroxycinnamate derivatives. Differences between genotypes were, however, recorded in amplitude and kinetic of variation in these groups. Occurrence of oxidation and polymerization reactions is proposed, based on the browning process of infected tissues, but whether some by-products act in defense as toxic compounds remain to be tested. Among direct antibacterial constitutive compounds present in apple leaves, the dihydrochalcone phloretin only was found at levels close to lethal concentrations in both genotypes. However, E. amylovora exhibited the ability to stabilize this compound at sublethal levels even in the resistant apple, rejecting the hypothesis of its involvement in the resistance of this genotype. PMID:18275458

  1. Effect of cover crop and premergence herbicides on the control of ALS-Resistant Palmer Amaranth (Amaranthus palmeri) in peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Palmer amaranth is a troublesome species across most of the southeastern United States. Resistance to acetolactate synthase (ALS) inhibiting herbicides has made control of Palmer amaranth even more difficult for peanut producers. Field studies were conducted in 2007 and 2008 to determine the impac...

  2. Plant resistance management strategies for greenbug (Schizaphis graminum (Rondani)) (Homoptera: Aphididae) in wheat-sorghum cropping systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biotypic diversity of the greenbug, Schizaphis graminum (Rondani), has been a primary concern to breeding programs for wheat and sorghum in the United States since the 1960's. Strategies for developing plant resistance have stressed the use of tolerance with the belief that it would be less selecti...

  3. Genome Sequence of the Plant Endophyte Bacillus pumilus INR7, Triggering Induced Systemic Resistance in Field Crops

    PubMed Central

    Jeong, Haeyoung; Choi, Soo-Keun; Kloepper, Joseph W.

    2014-01-01

    Bacillus pumilus INR7 is an endophytic bacterium that has been commercialized as a biological control product against soilborne pathogens as well as foliar pathogens by direct antagonism and induction of systemic resistance. In the current study, we provide the genome sequence and a possible explanation of the function of strain INR7. PMID:25359912

  4. Kinetics of isochronal austenization in modified high Cr ferritic heat-resistant steel

    NASA Astrophysics Data System (ADS)

    Liu, Chenxi; Liu, Yongchang; Zhang, Dantian; Yan, Zesheng

    2011-12-01

    Employment of high Cr ferritic steels as a main structural material is considered as a way to achieve economical competitiveness of main steam pipe and nuclear reactors in power plants. Differential dilatometry and microstructure observation were employed to investigate the isochronal austenitic transformation of the modified high Cr ferritic steel. The kinetics of the isochronal austenitic transformation were described by a phase-transformation model involving site saturation (pre-existing nuclei), diffusion-controlled growth, and incorporating an impingement correction. The experimental results and kinetic analysis indicate that an increase of the heating rate promotes the diffusion-controlled austenitic transformation. The dissolving degree of precipitates during the austenization process affects the activation energy for diffusion and the undissolved precipitates lead to an increase of the onset temperature of the subsequent martensite transformation upon cooling.

  5. Surface characterization of plasma-modified resist patterns by ToF-SIMS analysis

    NASA Astrophysics Data System (ADS)

    Park, Jong S.; Kim, Hyung-jun

    2009-12-01

    We report the use of the time-of-flight secondary ion mass spectrometry (ToF-SIMS) technique to determine whether the patterned bank is suitable for inkjet printing, by evaluating the phobicity contrast between two regions, the glass substrate inside pixels and the surface of the resist bank. We first examined the effect of plasma treatment on the ink spreading behavior inside pixels. The phobicity contrast was optimized by removing residues inside the pixels and by providing high phobicity on the bank surface. We show that ToF-SIMS spectra and mass-resolved images are effective tools in examining the existence of organic contaminants inside pixels and predicting the actual inkjet printing behavior. The ToF-SIMS technique will find promising applications that are related to surface characteristics where conventional contact angle measurement is hard to apply due to geometrical and technical restrictions.

  6. Reprogramming to a pluripotent state modifies mesenchymal stem cell resistance to oxidative stress

    PubMed Central

    Asensi, Karina D; Fortunato, Rodrigo S; dos Santos, Danúbia S; Pacheco, Thaísa S; de Rezende, Danielle F; Rodrigues, Deivid C; Mesquita, Fernanda C P; Kasai-Brunswick, Tais H; de Carvalho, Antonio C Campos; Carvalho, Denise P; Carvalho, Adriana B; Goldenberg, Regina C dos S

    2014-01-01

    Properties of induced pluripotent stem cells (iPSC) have been extensively studied since their first derivation in 2006. However, the modification in reactive oxygen species (ROS) production and detoxification caused by reprogramming still needs to be further elucidated. The objective of this study was to compare the response of iPSC generated from menstrual blood–derived mesenchymal stem cells (mb-iPSC), embryonic stem cells (H9) and adult menstrual blood–derived mesenchymal stem cells (mbMSC) to ROS exposure and investigate the effects of reprogramming on cellular oxidative stress (OS). mbMSC were extremely resistant to ROS exposure, however, mb-iPSC were 10-fold less resistant to H2O2, which was very similar to embryonic stem cell sensitivity. Extracellular production of ROS was also similar in mb-iPSC and H9 and almost threefold lower than in mbMSC. Furthermore, intracellular amounts of ROS were higher in mb-iPSC and H9 when compared with mbMSC. As the ability to metabolize ROS is related to antioxidant enzymes, we analysed enzyme activities in these cell types. Catalase and superoxide dismutase activities were reduced in mb-iPSC and H9 when compared with mbMSC. Finally, cell adhesion under OS conditions was impaired in mb-iPSC when compared with mbMSC, albeit similar to H9. Thus, reprogramming leads to profound modifications in extracellular ROS production accompanied by loss of the ability to handle OS. PMID:24528612

  7. Protein adsorption resistance of PVP-modified polyurethane film prepared by surface-initiated atom transfer radical polymerization

    NASA Astrophysics Data System (ADS)

    Yuan, Huihui; Qian, Bin; Zhang, Wei; Lan, Minbo

    2016-02-01

    An anti-fouling surface of polyurethane (PU) film grafted with Poly(N-vinylpyrrolidone) (PVP) was prepared through surface-initiated atom transfer radical polymerization (SI-ATRP). And the polymerization time was investigated to obtain PU films with PVP brushes of different lengths. The surface properties and protein adsorption of modified PU films were evaluated. The results showed that the hydrophilicity of PU-PVP films were improved with the increase of polymerization time, which was not positive correlation with the surface roughness due to the brush structure. Additionally, the protein resistance performance was promoted when prolonging the polymerization time. The best antifouling PU-PVP (6.0 h) film reduced the adsoption level of bovine serum albumin (BSA), lysozyme (LYS), and brovin serum fibrinogen (BFG) by 93.4%, 68.3%, 85.6%, respectively, compared to the unmodified PU film. The competitive adsorption of three proteins indicated that LYS preferentially adsorbed on the modified PU film, while BFG had the lowest adsorption selectivity. And the amount of BFG on PU-PVP (6.0 h) film reduced greatly to 0.08 μg/cm2, which was almost one-tenth of its adsorption from the single-protein system. Presented results suggested that both hydrophilicity and surface roughness might be the important factors in all cases of protein adsorption, and the competitive or selective adsorption might be related to the size of the proteins, especially on the non-charged films.

  8. Improvement of the electrochromic response of a low-temperature sintered dye-modified porous electrode using low-resistivity indium tin oxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Watanabe, Yuichi; Suemori, Kouji; Hoshino, Satoshi

    2016-06-01

    An indium tin oxide (ITO) nanoparticle-based porous electrode sintered at low temperatures was investigated as a transparent electrode for electrochromic displays (ECDs). The electrochromic (EC) response of the dye-modified ITO porous electrode sintered at 150 °C, which exhibited a generally low resistivity, was markedly superior to that of a conventional dye-modified TiO2 porous electrode sintered at the same temperature. Moreover, the EC characteristics of the dye-modified ITO porous electrode sintered at 150 °C were better than those of the high-temperature (450 °C) sintered conventional dye-modified TiO2 porous electrode. These improvements in the EC characteristics of the dye-modified ITO porous electrode are attributed to its lower resistivity than that of the TiO2 porous electrodes. In addition to its sufficiently low resistivity attained under the sintering conditions required for flexible ECD applications, the ITO porous film had superior visible-light transparency and dye adsorption capabilities. We conclude that the process temperature, resistivity, optical transmittance, and dye adsorption capability of the ITO porous electrode make it a promising transparent porous electrode for flexible ECD applications.

  9. The Lipid-Modifying Multiple Peptide Resistance Factor Is an Oligomer Consisting of Distinct Interacting Synthase and Flippase Subunits

    PubMed Central

    Kuhn, Sebastian; Slavetinsky, Christoph J.; Krismer, Bernhard; Heilbronner, Simon; Gekeler, Cordula; Kraus, Dirk; Wagner, Samuel; Peschel, Andreas

    2015-01-01

    ABSTRACT  Phospholipids are synthesized at the inner leaflet of the bacterial cytoplasmic membrane but have to be translocated to the outer leaflet to maintain membrane lipid bilayer composition and structure. Even though phospholipid flippases have been proposed to exist in bacteria, only one such protein, MprF, has been described. MprF is a large integral membrane protein found in several prokaryotic phyla, whose C terminus modifies phosphatidylglycerol (PG), the most common bacterial phospholipid, with lysine or alanine to modulate the membrane surface charge and, as a consequence, confer resistance to cationic antimicrobial agents such as daptomycin. In addition, MprF is a flippase for the resulting lipids, Lys-PG or Ala-PG. Here we demonstrate that the flippase activity resides in the N-terminal 6 to 8 transmembrane segments of the Staphylococcus aureus MprF and that several conserved, charged amino acids and a proline residue are crucial for flippase function. MprF protects S. aureus against the membrane-active antibiotic daptomycin only when both domains are present, but the two parts do not need to be covalently linked and can function in trans. The Lys-PG synthase and flippase domains were each found to homo-oligomerize and also to interact with each other, which illustrates how the two functional domains may act together. Moreover, full-length MprF proteins formed oligomers, indicating that MprF functions as a dimer or larger oligomer. Together our data reveal how bacterial phospholipid flippases may function in the context of lipid biosynthetic processes. Importance  Bacterial cytoplasmic membranes are crucial for maintaining and protecting cellular integrity. For instance, they have to cope with membrane-damaging agents such as cationic antimicrobial peptides (CAMPs) produced by competing bacteria (bacteriocins), secreted by eukaryotic host cells (defensins), or used as antimicrobial therapy (daptomycin). The MprF protein is found in many Gram

  10. Staphylococcal Phenotypes Induced by Naturally Occurring and Synthetic Membrane-Interactive Polyphenolic β-Lactam Resistance Modifiers

    PubMed Central

    Palacios, Lucia; Rosado, Helena; Micol, Vicente; Rosato, Adriana E.; Bernal, Patricia; Arroyo, Raquel; Grounds, Helen; Anderson, James C.; Stabler, Richard A.; Taylor, Peter W.

    2014-01-01

    Galloyl catechins, in particular (-)-epicatechin gallate (ECg), have the capacity to abrogate β-lactam resistance in methicillin-resistant strains of Staphylococcus aureus (MRSA); they also prevent biofilm formation, reduce the secretion of a large proportion of the exoproteome and induce profound changes to cell morphology. Current evidence suggests that these reversible phenotypic traits result from their intercalation into the bacterial cytoplasmic membrane. We have endeavoured to potentiate the capacity of ECg to modify the MRSA phenotype by stepwise removal of hydroxyl groups from the B-ring pharmacophore and the A:C fused ring system of the naturally occurring molecule. ECg binds rapidly to the membrane, inducing up-regulation of genes responsible for protection against cell wall stress and maintenance of membrane integrity and function. Studies with artificial membranes modelled on the lipid composition of the staphylococcal bilayer indicated that ECg adopts a position deep within the lipid palisade, eliciting major alterations in the thermotropic behaviour of the bilayer. The non-galloylated homolog (-)-epicatechin enhanced ECg-mediated effects by facilitating entry of ECg molecules into the membrane. ECg analogs with unnatural B-ring hydroxylation patterns induced higher levels of gene expression and more profound changes to MRSA membrane fluidity than ECg but adopted a more superficial location within the bilayer. ECg possessed a high affinity for the positively charged staphylococcal membrane and induced changes to the biophysical properties of the bilayer that are likely to account for its capacity to disperse the cell wall biosynthetic machinery responsible for β-lactam resistance. The ability to enhance these properties by chemical modification of ECg raises the possibility that more potent analogs could be developed for clinical evaluation. PMID:24699700

  11. N-Terminally Modified Linear and Branched Spermine Backbone Dipeptidomimetics against Planktonic and Sessile Methicillin-Resistant Staphylococcus aureus

    PubMed Central

    Dewangan, Rikeshwer Prasad; Joshi, Seema; Kumari, Shalini; Gautam, Hemlata; Yar, Mohammed Shahar

    2014-01-01

    Toward the discovery of useful therapeutic molecules, we report the design and synthesis of a focused library of new ultrashort N-terminally modified dipeptidomimetics, with or without modifications in the spermine backbone leading to linear (series 1) or branched (series 2) tryptophans, as antimicrobial agents. Eight peptidomimetics in the library showed good antibacterial activity (MICs of 1.77 to 14.2 μg/ml) against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis bacterial strains. Tryptophan fluorescence measurements on artificial bacterial or mammalian mimic membranes and assessment of the MRSA potential depolarization ability of the designed compounds revealed membrane interactions dependent on tryptophan positioning and N-terminal tagging. Among active peptidomimetics, compounds 1c and 1d were found to be nonhemolytic, displaying rapid bactericidal activity (at 4× MIC) against exponentially growing MRSA. Further, scanning electron microscopy of peptidomimetic 1c- and 1d-treated MRSA showed morphological changes with damage to cell walls, defining a membrane-active mode of action. Moreover, peptidomimetics 1c and 1d did not induce significant drug resistance in MRSA even after 17 passages. We also investigated the activity of these molecules against MRSA biofilms. At sub-MIC levels (∼2 to 4 μg/ml), both peptidomimetics inhibited biofilm formation. At concentrations higher than the MIC (35 to 140 μg/ml), peptidomimetics 1c and 1d significantly reduced the metabolic activity and biomass of mature (24-h) MRSA biofilms. These results were corroborated by confocal laser scanning microscopy (live/dead assay). The in vitro protease stability and lower cytotoxicity of peptidomimetics against peripheral blood mononuclear cells (PBMCs) support them being novel staphylocidal peptidomimetics. In conclusion, this study provides two peptidomimetics as potential leads for treatment of staphylococcal infections

  12. Cover Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops are great tools to improve soil quality and health, and great tools to increase carbon sequestration. They are nutrient management tools that can help scavenge nitrate, cycle nitrogen to the following crop, mine NO3 from groundwater, and increase nitrogen use efficiency of cropping syste...

  13. Microstructural Study on Oxidation Resistance of Nonmodified and Platinum Modified Aluminide Coating

    NASA Astrophysics Data System (ADS)

    Zagula-Yavorska, Maryana; Sieniawski, Jan

    2014-03-01

    Platinum electroplating layers (3 and 7 μm thick) were deposited on the surface of the Inconel 713 LC, CMSX 4, and Inconel 625 Ni-base superalloys. Diffusion treatment at 1050°C for 2 h under argon atmosphere was performed after electroplating. Diffusion treated samples were aluminized according to the low activity CVD process at 1050°C for 8 h. The nonmodified aluminide coatings consist of NiAl phase. Platinum modification let to obtain the (Ni,Pt)Al phase in coatings. The coated samples were subjected to cyclic oxidation testing at 1100°C. It was discovered that increase of the platinum electroplating thickness from 3 to 7 μm provides the improvement of oxidation resistance of aluminide coatings. Increase of the platinum thickness causes decreases in weight change and decreases in parabolic constant during oxidation. The platinum provides the pure Al2O3 oxide formation, slow growth oxide layer, and delay the oxide spalling during heating-cooling thermal cycles.

  14. Manufacture of a heat-resistant alloy with modified specifications for HTGR structural applications

    SciTech Connect

    Sahira, K.; Kondo, T.; Takeiri, T.

    1984-07-01

    A method of manufacturing a nuclear grade nickel-base heat-resistant alloy in application to heliumcooled reactor primary circuit components has been developed. The Hastelloy-XR alloy, a version of Hastelloy-X, was made available by combining the basic studies of the oxidation behavior of Hastelloy-X and the improvement of manufacturing techniques. In the primary and remelting steps, the choice of appropriate processes was made by performing numerical analyses of the statistical deviation of both chemical composition and the products' mechanical properties. The feasibility of making larger electroslag remelting ingots with reasonable control of macrosegregation was examined by the calculation of a molten metal pool shape during melting. The hot workability of Hastelloy-XR was confirmed to be equivalent to that of Hastelloy-X and the importance of controlling the thermal and mechanical processes more closely was stressed in obtaining a higher level of quality assurance for the nuclear applications. The possibility of enhancing the high-temperature mechanical performance of Hastelloy-XR was suggested based on the preliminary test results with the heats manufactured with controlled boron content.

  15. Evaluation of three herbicide resistance genes for use in genetic transformations and for potential crop protection in algae production.

    PubMed

    Brueggeman, Andrew J; Bruggeman, Andrew J; Kuehler, Daniel; Weeks, Donald P

    2014-09-01

    Genes conferring resistance to the herbicides glyphosate, oxyfluorfen and norflurazon were developed and tested for use as dominant selectable markers in genetic transformation of Chlamydomonas reinhardtii and as potential tools for the protection of commercial-scale algal production facilities against contamination by organisms sensitive to these broad-spectrum herbicides. A synthetic glyphosate acetyltransferase (GAT) gene, when fitted with a strong Chlamydomonas promoter, conferred a 2.7×-fold increase in tolerance to the EPSPS inhibitor, glyphosate, in transgenic cells compared with progenitor WT cells. A mutant Chlamydomonas protoporphyrinogen oxidase (protox, PPO) gene previously shown to produce an enzyme insensitive to PPO-inhibiting herbicides, when genetically engineered, generated transgenic cells able to tolerate up to 136× higher levels of the PPO inhibitor, oxyfluorfen, than nontransformed cells. Genetic modification of the Chlamydomonas phytoene desaturase (PDS) gene-based gene sequences found in various norflurazon-resistant organisms allowed production of transgenic cells tolerant to 40× higher levels of norflurazon than nontransgenic cells. The high efficiency of all three herbicide resistance genes in producing transgenic cells demonstrated their suitability as dominant selectable markers for genetic transformation of Chlamydomonas and, potentially, other eukaryotic algae. However, the requirement for high concentrations of glyphosate and its associated negative effects on cell growth rates preclude its consideration for use in large-scale production facilities. In contrast, only low doses of norflurazon and oxyfluorfen (~1.5 μm and ~0.1 μm, respectively) are required for inhibition of cell growth, suggesting that these two herbicides may prove effective in large-scale algal production facilities in suppressing growth of organisms sensitive to these herbicides. PMID:24796724

  16. The present status of commercialized and developed biotech (GM) crops, results of evaluation of plum 'HoneySweet" for resistance to plum pox virus in the Czech Republic

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercialization of biotech (GM) crops started in 1996. A significant increase of 9 million hectars was realized in 1996-2009. In the years 2010-2011, it was already 12 million hectars (8 percent of total crop area). 16.7 million farmers in 29 countries planted 160 million hectars of GM crops in...

  17. Persistent Overexpression of Phosphoglycerate Mutase, a Glycolytic Enzyme, Modifies Energy Metabolism and Reduces Stress Resistance of Heart in Mice

    PubMed Central

    Shioi, Tetsuo; Kato, Takao; Inuzuka, Yasutaka; Kawashima, Tsuneaki; Tamaki, Yodo; Kawamoto, Akira; Tanada, Yohei; Iwanaga, Yoshitaka; Narazaki, Michiko; Matsuda, Tetsuya; Adachi, Souichi; Soga, Tomoyoshi; Takemura, Genzou; Kondoh, Hiroshi; Kita, Toru; Kimura, Takeshi

    2013-01-01

    Background Heart failure is associated with changes in cardiac energy metabolism. Glucose metabolism in particular is thought to be important in the pathogenesis of heart failure. We examined the effects of persistent overexpression of phosphoglycerate mutase 2 (Pgam2), a glycolytic enzyme, on cardiac energy metabolism and function. Methods and Results Transgenic mice constitutively overexpressing Pgam2 in a heart-specific manner were generated, and cardiac energy metabolism and function were analyzed. Cardiac function at rest was normal. The uptake of analogs of glucose or fatty acids and the phosphocreatine/βATP ratio at rest were normal. A comprehensive metabolomic analysis revealed an increase in the levels of a few metabolites immediately upstream and downstream of Pgam2 in the glycolytic pathway, whereas the levels of metabolites in the initial few steps of glycolysis and lactate remained unchanged. The levels of metabolites in the tricarboxylic acid (TCA) cycle were altered. The capacity for respiration by isolated mitochondria in vitro was decreased, and that for the generation of reactive oxygen species (ROS) in vitro was increased. Impaired cardiac function was observed in response to dobutamine. Mice developed systolic dysfunction upon pressure overload. Conclusions Constitutive overexpression of Pgam2 modified energy metabolism and reduced stress resistance of heart in mice. PMID:23951293

  18. Arabidopsis COPPER MODIFIED RESISTANCE1/PATRONUS1 is essential for growth adaptation to stress and required for mitotic onset control.

    PubMed

    Juraniec, Michal; Heyman, Jefri; Schubert, Veit; Salis, Pietrino; De Veylder, Lieven; Verbruggen, Nathalie

    2016-01-01

    The mitotic checkpoint (MC) guards faithful sister chromatid segregation by monitoring the attachment of spindle microtubules to the kinetochores. When chromosome attachment errors are detected, MC delays the metaphase-to-anaphase transition through the inhibition of the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase. In contrast to yeast and mammals, our knowledge on the proteins involved in MC in plants is scarce. Transient synchronization of root tips as well as promoter-reporter gene fusions were performed to analyze temporal and spatial expression of COPPER MODIFIED RESISTANCE1/PATRONUS1 (CMR1/PANS1) in developing Arabidopsis thaliana seedlings. Functional analysis of the gene was carried out, including CYCB1;2 stability in CMR1/PANS1 knockout and overexpressor background as well as metaphase-anaphase chromosome status. CMR1/PANS1 is transcriptionally active during M phase. Its deficiency provokes premature cell cycle exit and in consequence a rapid consumption of the number of meristematic cells in particular under stress conditions that are known to affect spindle microtubules. Root growth impairment is correlated with a failure to delay the onset of anaphase, resulting in anaphase bridges and chromosome missegregation. CMR1/PANS1 overexpression stabilizes the mitotic CYCB1;2 protein. Likely, CMR1/PANS1 coordinates mitotic cell cycle progression by acting as an APC/C inhibitor and plays a key role in growth adaptation to stress. PMID:26261921

  19. Looking forward to genetically edited fruit crops.

    PubMed

    Nagamangala Kanchiswamy, Chidananda; Sargent, Daniel James; Velasco, Riccardo; Maffei, Massimo E; Malnoy, Mickael

    2015-02-01

    The availability of genome sequences for many fruit crops has redefined the boundaries of genetic engineering and genetically modified (GM) crop plants. However commercialization of GM crops is hindered by numerous regulatory and social hurdles. Here, we focus on recently developed genome-editing tools for fruit crop improvement and their importance from the consumer perspective. Challenges and opportunities for the deployment of new genome-editing tools for fruit plants are also discussed. PMID:25129425

  20. TRACKING GENE FLOW FROM A GENETICALLY MODIFIED CREEPING BENTGRASS -- METHODS, MEASURES AND LESSONS LEARNED

    EPA Science Inventory

    Creeping bentgrass (CBG) expressing an engineered gene for resistance to glyphosate herbicide is one of the first genetically modified (GM) perennial crops to undergo regulatory review for commercial release by the US Department of Agriculture Animal Plant Health and Inspection S...

  1. Crop Biotechnology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of crop biotechnology on outcomes of agricultural practices and economics is readily evidenced by the escalating acreage of genetically engineered crops, all occurring in a relatively short time span. Until the mid 1990s, virtually no acreage was planted with commercial genetically mo...

  2. Crop residues

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop residues [e.g., corn (Zea mays) stover and small grain straw] are sometimes excluded when discussing cellulosic energy crops per se, but because of the vast area upon which they are grown and their current role in the development of cellulosic energy systems. This chapter focuses on current cor...

  3. A functional Small Ubiquitin-like Modifier (SUMO) interacting motif (SIM) in the gibberellin hormone receptor GID1 is conserved in cereal crops and disrupting this motif does not abolish hormone dependency of the DELLA-GID1 interaction

    PubMed Central

    Nelis, Stuart; Conti, Lucio; Zhang, Cunjin; Sadanandom, Ari

    2015-01-01

    Plants survive adversity by modulating their growth in response to changing environmental signals. The phytohormone Gibberellic acid (GA) plays a central role in regulating these adaptive responses by stimulating the degradation of growth repressing DELLA proteins which accumulate during stress. The current model for GA signaling describes how this hormone binds to its receptor GID1 so promoting association of GID1 with DELLA, which then undergoes ubiquitin-mediated proteasomal degradation. Recent data revealed that conjugation of DELLAs to the Small Ubiquitin-like Modifier (SUMO) protein enables plants to modulate its abundance during environmental stress. This is achieved by SUMOylated DELLAs sequestering GID1 via its SUMO interacting motif (SIM) allowing non-SUMOylated DELLAs to accumulate leading to growth restraint under stress and potential yield loss. We demonstrate that GID1 proteins across the major cereal crops contain a functional SIM able to bind SUMO1. Site directed mutagenesis and yeast 2 hybrid experiments reveal that it is possible to disrupt the SIM-SUMO interaction motif without affecting the GA dependent DELLA–GID1 interaction and thereby uncoupling SUMO–mediated inhibition from DELLA degradation. Arabidopsis plants overexpressing a SIM mutant allele of GID1 perform better at relieving DELLA restraint than wild–type GID1. This evidence suggests that manipulating the SIM motif in the GA receptor may provide a possible route to developing stress tolerant crops plants. PMID:25761145

  4. Transcriptional analysis of susceptible and resistant European corn borer strains and their response to Cry1F protoxin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of insect resistance to pesticides and biological toxins expressed by genetically modified crop plants is a serious threat to sustainable agricultural production. One of the central goals of insect resistance management (IRM) is to understand the evolution and adaptation of pest inse...

  5. Innate and Introduced Resistance Traits in Genetically Modified Aspen Trees and Their Effect on Leaf Beetle Feeding

    PubMed Central

    Hjältén, Joakim; Axelsson, E. Petter; Julkunen-Tiitto, Riitta; Wennström, Anders; Pilate, Gilles

    2013-01-01

    Genetic modifications of trees may provide many benefits, e.g. increase production, and mitigate climate change and herbivore impacts on forests. However, genetic modifications sometimes result in unintended effects on innate traits involved in plant-herbivore interactions. The importance of intentional changes in plant defence relative to unintentional changes and the natural variation among clones used in forestry has not been evaluated. By a combination of biochemical measurements and bioassays we investigated if insect feeding on GM aspens is more affected by intentional (induction Bt toxins) than of unintentional, non-target changes or clonal differences in innate plant defence. We used two hybrid wildtype clones (Populus tremula x P. tremuloides and Populus tremula x P. alba) of aspen that have been genetically modified for 1) insect resistance (two Bt lines) or 2) reduced lignin properties (two lines COMT and CAD), respectively. Our measurements of biochemical properties suggest that unintended changes by GM modifications (occurring due to events in the transformation process) in innate plant defence (phenolic compounds) were generally smaller but fundamentally different than differences seen among different wildtype clones (e.g. quantitative and qualitative, respectively). However, neither clonal differences between the two wildtype clones nor unintended changes in phytochemistry influenced consumption by the leaf beetle (Phratora vitellinae). By contrast, Bt induction had a strong direct intended effect as well as a post experiment effect on leaf beetle consumption. The latter suggested lasting reduction of beetle fitness following Bt exposure that is likely due to intestinal damage suffered by the initial Bt exposure. We conclude that Bt induction clearly have intended effects on a target species. Furthermore, the effect of unintended changes in innate plant defence traits, when they occur, are context dependent and have in comparison to Bt induction

  6. Application of laws, policies, and guidance from the United States and Canada to the regulation of food and feed derived from genetically modified crops: interpretation of composition data.

    PubMed

    Price, William D; Underhill, Lynne

    2013-09-01

    With the development of recombinant DNA techniques for genetically modifying plants to exhibit beneficial traits, laws and regulations were adopted to ensure the safety of food and feed derived from such plants. This paper focuses on the regulation of genetically modified (GM) plants in Canada and the United States, with emphasis on the results of the compositional analysis routinely utilized as an indicator of possible unintended effects resulting from genetic modification. This work discusses the mandate of Health Canada and the Canadian Food Inspection Agency as well as the U.S. Food and Drug Administration's approach to regulating food and feed derived from GM plants. This work also addresses how publications by the Organisation for Economic Co-operation and Development and Codex Alimentarius fit, particularly with defining the importance and purpose of compositional analysis. The importance of study design, selection of comparators, use of literature, and commercial variety reference values is also discussed. PMID:23865444

  7. Prevalence and antibiotic resistance pattern of Salmonella serovars in integrated crop-livestock farms and their products sold in local markets.

    PubMed

    Peng, Mengfei; Salaheen, Serajus; Almario, Jose Alejandro; Tesfaye, Bezait; Buchanan, Robert; Biswas, Debabrata

    2016-05-01

    Major concern in the Mixed Crop-Livestock (MCL) farms, in which livestock and vegetables grown closely in the same facility, is cross-contamination of zoonotic bacterial pathogens especially Salmonella. To investigate the distribution of Salmonella serovars in MCL and their products, a total of 1287 pre-harvest samples from various farms and 1377 post-harvest samples from retail supermarkets in Maryland and Washington D.C. areas were collected and analysed. A total of 315 Salmonella isolates were recovered, with 17.44% and 5.88%, from MCL and conventional farms samples (P < 0.001). At post-harvest level, the prevalence of Salmonella was 30.95%, 19.83%, and 8.38% in chicken meat (P < 0.001) from farmers, organic, and conventional retail markets respectively, and 16.81% and 6.06% in produce products (P < 0.001) from farmers and organic retail markets, but none from conventional retail markets. From the isolated Salmonella, 34.50% was confirmed S. Typhimurium, followed by S. Heidelberg (10.86%) and S. Enteritidis (9.90%). The overall multi-antibiotic resistance in recovered Salmonella was 23.81% versus 4.55% in conventional and MCL farms (P = 0.004) and 66.67% versus 7.76% in conventional and farmers markets (P < 0.001). Overall the data reveals higher Salmonella risks in MCL farms' environment and their products sold in farmers markets and warrants taking necessary measures to limit Salmonella transmission. PMID:26914740

  8. Host Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concepts covered in this chapter (for an undergraduate text book) • Disease resistance is a crucial trait for any crop plant. • The degree of disease resistance varies within plant populations. Much of this variation has a genetic basis. • Plant disease resistance can be broadly categorized into s...

  9. Human health concerns with GM crops.

    PubMed

    Malarkey, Trish

    2003-11-01

    Biotechnology was used in the first generation of so-called 'GM' crops to provide growers with complimentary and sometimes alternative crop management solutions to pesticides. Selected host genes or genes identified from other plants or non-plant sources are modified or transferred to a crop plant. The new or altered protein expression resulting from these modifications confer on the plant a desired physiological trait, such as resistance to particular herbicides or insect pests. Second generation modifications provide traits such as enhanced nutritional or health-promoting characteristics that are of benefit to consumers. The commonly raised concerns about possible implications for human health are: inherent toxicity of the novel gene and their products, the potential to express novel antigenic proteins or alter levels of existing protein allergens, the potential for unintended effects resulting from alterations of host metabolic pathways or over expression of inherently toxic or pharmacologically active substances and the potential for nutrient composition in the new food occur differing significantly from a conventional counterpart. Foods produced using biotechnology are subjected to far greater levels of scrutiny than foods produced by traditional plant breeding techniques. The accepted analytical, nutritional and toxicological methods employed to support this scrutiny and to assess and assure that a 'GM' food is a safe and nutritious as its 'non-GM' counterpart are discussed. The challenges associated with identifying unintended effects in whole GM foods and the promise new (proteomics/genomic) technologies offer opposite traditional toxicity testing paradigms are appraised. PMID:14644323

  10. Elevated CO2 alters the feeding behaviour of the pea aphid by modifying the physical and chemical resistance of Medicago truncatula.

    PubMed

    Guo, Huijuan; Sun, Yucheng; Li, Yuefei; Liu, Xianghui; Wang, Pingyan; Zhu-Salzman, Keyan; Ge, Feng

    2014-09-01

    Elevated CO(2) compromises the resistance of leguminous plants against chewing insects, but little is known about whether elevated CO(2) modifies the resistance against phloem-sucking insects or whether it has contrasting effects on the resistance of legumes that differ in biological nitrogen fixation. We tested the hypothesis that the physical and chemical resistance against aphids would be increased in Jemalong (a wild type of Medicago truncatula) but would be decreased in dnf1 (a mutant without biological nitrogen fixation) by elevated CO(2). The non-glandular and glandular trichome density of Jemalong plants increased under elevated CO(2), resulting in prolonged aphid probing. In contrast, dnf1 plants tended to decrease foliar trichome density under elevated CO(2), resulting in less surface and epidermal resistance to aphids. Elevated CO(2) enhanced the ineffective salicylic acid-dependent defence pathway but decreased the effective jasmonic acid/ethylene-dependent defence pathway in aphid-infested Jemalong plants. Therefore, aphid probing time decreased and the duration of phloem sap ingestion increased on Jemalong under elevated CO(2), which, in turn, increased aphid growth rate. Overall, our results suggest that elevated CO(2) decreases the chemical resistance of wild-type M. truncatula against aphids, and that the host's biological nitrogen fixation ability is central to this effect. PMID:24697655

  11. Do whole-body vibration exercise and resistance exercise modify concentrations of salivary cortisol and immunoglobulin A?

    PubMed

    Roschel, H; Barroso, R; Batista, M; Ugrinowitsch, C; Tricoli, V; Arsati, F; Lima-Arsati, Y B; Araújo, V C; Moreira, A

    2011-06-01

    A single bout of resistance exercise (RE) induces hormonal and immune responses, playing an important role in a long-term adaptive process. Whole-body vibration (WBV) has also been shown to affect hormonal responses. Evidence suggests that combining WBV with RE may amplify hormonal and immune responses due to the increased neuromuscular load. Therefore, the aim of this study was to evaluate salivary cortisol (Scortisol) and salivary IgA (SIgA) concentrations following a RE session combined or not with WBV. Nine university students (22.9 ± 5.1 years, 175.8 ± 5.2 cm, and 69.2 ± 7.3 kg) performed five sets of squat exercise (70% one-repetition-maximum) combined (R+V30) or not (R) with WBV at 30 Hz. Saliva samples were obtained before and after exercise. Subjects also rated their effort according to the Borg CR-10 scale (RPE). Data were analyzed by a mixed model. RPE was higher after R+V30 (8.3 ± 0.7) compared to R (6.2 ± 0.7). However, Scortisol (pre: 10.6 ± 7.6 and 11.7 ± 7.6, post: 8.3 ± 6.3 and 10.2 ± 7.2 ng/mL for R and R+V30, respectively) and SIgA concentrations (pre: 98.3 ± 22.6 and 116.1 ± 51.2, post: 116.6 ± 64.7 and 143.6 ± 80.5 µg/mL for R and R+V30, respectively) were unaffected. No significant correlations were observed between Scortisol and RPE (r = 0.45, P = 0.22; r = 0.30, P = 0.42, for R and R+V30, respectively). On the basis of these data, neither protocol modified salivary cortisol or IgA, although RPE was higher after R+V30 than R. PMID:21584438

  12. A comparative analysis of media reporting of perceived risks and benefits of genetically modified crops and foods in Kenyan and international newspapers.

    PubMed

    DeRosier, Christopher; Sulemana, Iddisah; James, Harvey S; Valdivia, Corinne; Folk, William; Smith, Randall D

    2015-07-01

    We empirically examine the reporting on biotechnology in Kenyan and international newspapers between 2010 and early 2014. We identify news articles that reported on biotechnology and analyze their use of words to determine whether there is a balance in the reporting of perceived risks and benefits. We also consider how the sources used in news articles and how the publication of the Séralini study of rats fed genetically modified maize affect the balance of reporting of perceived risks and benefits. We find that in Kenyan news reporting, more articles mention perceived benefits than risks, but when risks are mentioned, new articles contain more references to risks than to benefits. We also find that sources affect the reporting of perceived risks and benefits and that the Séralini study increased the likelihood that perceived risks are reported in Kenyan news reporting, but not in international newspapers. PMID:25605748

  13. GM crops and the rat digestive tract: a critical review.

    PubMed

    Zdziarski, I M; Edwards, J W; Carman, J A; Haynes, J I

    2014-12-01

    The aim of this review is to examine the relationship between genetically modified (GM) crops and health, based on histopathological investigations of the digestive tract in rats. We reviewed published long-term feeding studies of crops containing one or more of three specific traits: herbicide tolerance via the EPSPS gene and insect resistance via cry1Ab or cry3Bb1 genes. These genes are commonly found in commercialised GM crops. Our search found 21 studies for nine (19%) out of the 47 crops approved for human and/or animal consumption. We could find no studies on the other 38 (81%) approved crops. Fourteen out of the 21 studies (67%) were general health assessments of the GM crop on rat health. Most of these studies (76%) were performed after the crop had been approved for human and/or animal consumption, with half of these being published at least nine years after approval. Our review also discovered an inconsistency in methodology and a lack of defined criteria for outcomes that would be considered toxicologically or pathologically significant. In addition, there was a lack of transparency in the methods and results, which made comparisons between the studies difficult. The evidence reviewed here demonstrates an incomplete picture regarding the toxicity (and safety) of GM products consumed by humans and animals. Therefore, each GM product should be assessed on merit, with appropriate studies performed to indicate the level of safety associated with them. Detailed guidelines should be developed which will allow for the generation of comparable and reproducible studies. This will establish a foundation for evidence-based guidelines, to better determine if GM food is safe for human and animal consumption. PMID:25244705

  14. An Empirical Test of the F2 Screen for Detection of Bacillus thuringiensis-Resistance Alleles in Tobacco Budworm (Lepidoptera: Noctuidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insects exposed to genetically-modified crops expressing Bacillus thuringiensis (Bt) toxins are under intense selection pressure that could result in widespread Bt resistance. Screening for early indications of Bt resistance developing in targeted Lepidoptera is conducted in many of the regions wher...

  15. Globalization’s unexpected impact on soybean production in South America: linkages between preferences for non-genetically modified crops, eco-certifications, and land use

    NASA Astrophysics Data System (ADS)

    Garrett, Rachael D.; Rueda, Ximena; Lambin, Eric F.

    2013-12-01

    The land use impacts of globalization and of increasing global food and fuel demand depend on the trade relationships that emerge between consuming and producing countries. In the case of soybean production, increasing trade between South American farmers and consumers in Asia and Europe has facilitated soybean expansion in the Amazon, Chaco, and Cerrado biomes. While these telecouplings have been well documented, there is little understanding of how quality preferences influence trade patterns and supply chains, incentivizing or discouraging particular land use practices. In this study we provide empirical evidence that Brazil’s continued production of non-genetically modified (GM) soybeans has increased its competitive advantage in European countries with preferences against GM foods. Brazil’s strong trade relationship with European consumers has facilitated an upgrading of the soybean supply chain. Upgraded soybean supply chains create new conservation opportunities by allowing farmers to differentiate their products based on environmental quality in order to access premiums in niche markets in Europe. These interactions between GM preferences, trade flows, and supply chain structure help to explain why Brazilian soybean farmers have adopted environmental certification programs on a larger scale than Argentinian, Bolivian, Paraguayan, and Uruguayan soybean producers.

  16. Global crop forecasting

    NASA Technical Reports Server (NTRS)

    Macdonald, R. B.; Hall, F. G.

    1980-01-01

    The needs for and remote sensing means of global crop forecasting are discussed, and key results of the Large Area Crop Inventory Experiment (LACIE) are presented. Current crop production estimates provided by foreign countries are shown often to be inadequate, and the basic elements of crop production forecasts are reviewed. The LACIE project is introduced as a proof-of-concept experiment designed to assimilate remote sensing technology, monitor global wheat production, evaluate key technical problems, modify the technique accordingly and demonstrate the feasibility of a global agricultural monitoring system. The global meteorological data, sampling and aggregation techniques, Landsat data analysis procedures and yield forecast procedures used in the experiment are outlined. Accuracy assessment procedures employed to evaluate LACIE technology performance are presented, and improvements in system efficiency and capacity during the three years of operation are pointed out. Results of LACIE estimates of Soviet, U.S. and Canadian wheat production are presented which demonstrate the feasibility and accuracy of the remote-sensing approach for global food and fiber monitoring.

  17. Effect of lithium-ion diffusibility on interfacial resistance of LiCoO2 thin film electrode modified with lithium tungsten oxides

    NASA Astrophysics Data System (ADS)

    Hayashi, Tetsutaro; Miyazaki, Takamichi; Matsuda, Yasutaka; Kuwata, Naoaki; Saruwatari, Motoaki; Furuichi, Yuki; Kurihara, Koji; Kuzuo, Ryuichi; Kawamura, Junichi

    2016-02-01

    To investigate the contribution of lithium-ion diffusibility of lithium tungsten oxides (LWOs) to low interfacial resistance, we fabricate thin-film electrodes of 6Li-enriched LiCoO2 (6LCO) modified with various structure-types of 6Li-enriched LWOs by pulsed laser deposition. The electrodes are subjected to X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), and secondary-ion mass spectrometry (SIMS) analyses. XRD reveals that the LWO layers have Li2WO4 structure with rhombohedral and tetragonal symmetries and amorphous states. EIS shows that the lowest interfacial resistance of the positive electrodes is given by the amorphous state, followed in order by the tetragonal and the rhombohedral symmetry, and that the diffusion coefficients of lithium-ions in the electrodes increase in the same order. SIMS demonstrates that the fastest lithium-ion self-diffusibility into the LWOs is found in the amorphous state, followed in order by tetragonal and rhombohedral symmetry. Furthermore, the amorphous state LWO modification shows smooth lithium-ion diffusion between the LWO and LCO layers after the electrochemical test. Conversely, the rhombohedral LWO modification demonstrates congested lithium-ion diffusion between the LWO and LCO layers after the test. Thus, fast lithium-ion self-diffusibility into the LWO-modified LCO contributes to enhancing the diffusion of lithium-ions, resulting in the reduction of interfacial resistance.

  18. Genetically modified crops in a 10-generation feeding trial on Japanese quails--Evaluation of its influence on birds' performance and body composition.

    PubMed

    Sartowska, K E; Korwin-Kossakowska, A; Sender, G

    2015-12-01

    The effect of genetically modified (GM) feed components comprising soya bean meal and maize on the performance indices (reproduction, survival rate, growth, egg production, relative weight of chosen internal organs, and basic chemical composition of breast muscle and egg yolk) of Japanese quails was investigated during a 10-generation trial. A total number of 8,438 healthy quail chicks were used in the course of the trial. In each generation, birds were maintained in 3 experimental groups differing in the main feed components, i.e. 1) GM soya (Roundup Ready) and non-GM maize, 2) GM maize (MON810) and non-GM soya, and 3) non-GM soya and maize. The different feeds used did not influence any of the biological hatch indices, survival rate, or BW of young or adult quails. With regard to egg-laying performance, the GM maize group showed a better laying percentage and a higher egg mass production compared to the other groups; the GM soya group showed reduced average egg mass compared to the other groups, whereas the overall egg production level was the same as in the control group. Results showed a higher relative weight of breast muscle and gizzard in birds fed GM maize compared to the control group, whereas live BW and the relative weights of liver and heart were not different among groups. Meat from the GM soya group showed higher protein and lower fat levels compared to the control group. In the case of egg yolk, its chemical composition in the experimental groups did not differ from the control group. Even though some differences were found among the feeding groups, none could be judged as a negative influence of GM maize or GM soya in feed on the birds or final consumer products over 10 generations of Japanese quails. PMID:26475068

  19. Biotechnology Towards Energy Crops.

    PubMed

    Margaritopoulou, Theoni; Roka, Loukia; Alexopoulou, Efi; Christou, Myrsini; Rigas, Stamatis; Haralampidis, Kosmas; Milioni, Dimitra

    2016-03-01

    New crops are gradually establishing along with cultivation systems to reduce reliance on depleting fossil fuel reserves and sustain better adaptation to climate change. These biological assets could be efficiently exploited as bioenergy feedstocks. Bioenergy crops are versatile renewable sources with the potential to alternatively contribute on a daily basis towards the coverage of modern society's energy demands. Biotechnology may facilitate the breeding of elite energy crop genotypes, better suited for bio-processing and subsequent use that will improve efficiency, further reduce costs, and enhance the environmental benefits of biofuels. Innovative molecular techniques may improve a broad range of important features including biomass yield, product quality and resistance to biotic factors like pests or microbial diseases or environmental cues such as drought, salinity, freezing injury or heat shock. The current review intends to assess the capacity of biotechnological applications to develop a beneficial bioenergy pipeline extending from feedstock development to sustainable biofuel production and provide examples of the current state of the art on future energy crops. PMID:26798073

  20. Sunflower crop

    SciTech Connect

    Beard, B.H.

    1981-05-01

    A review of the sunflower as a major commercial crop, including its history, cultivation, hybridization and uses. It is grown principally for its oil which is high in polyunsaturated fatty acids and used in a variety of foods. Recently it has been tested in diesel engines and a high protein meal is produced from the seed residues.

  1. Characterizing Nitrous Oxide (N2O) Emissions over a Wheat-based Cropping System in the Northwest United States Using the Modified Bowen Ratio Technique and Static Chambers

    NASA Astrophysics Data System (ADS)

    Waldo, Sarah; Kostyanovsky, Kirill; O'Keeffe, Patrick; Pressley, Shelley; Huggins, Dave; Stockle, Claudio; Lamb, Brian

    2015-04-01

    Nitrous oxide (N2O) is a potent greenhouse gas and ozone depleting substance. Agricultural soils are the primary source of N2O, which is created as a by-product of soil microbial processes. The production and emission of N2O is characterized by high spatial and temporal variability, or "hot spots" and "hot moments". These behaviors, along with limitations in instrument sensitivity to N2O, are challenges in characterizing emissions. Many studies have monitored N2O emissions using either static chambers or micrometeorological measurements or the two methods together. The two techniques are complementary: chamber methods have a lower detection limit and are more reliable as their operation does not depend on atmospheric conditions, but may not capture spatial variability even with multiple chambers. Tower-based methods are subject to relatively high data loss due to non-ideal conditions and to less sensitive detection limits, but have a larger measurement footprint and can characterize field-scale emissions. This study aims to characterize a long-term, field-scale N2O budget over two winter wheat fields located in the Inland Pacific Northwest of the United States, both in terms of an annual emission budget and in terms of understanding what causes hot moments. We combined continuous measurements of N2O emissions from a system of sixteen automated, static chambers with tower-based measurements of N2O fluxes. We used the modified Bowen ratio (MBR) technique with temperature as a tracer. Preliminary results indicate that freeze-thaw cycles in the winter make up a higher percentage of annual emissions than previously thought. Furthermore, comparison of the chamber results to the tower-based measurements imply that the chambers may be underestimating field-scale N2O fluxes because they are not adequately capturing hot spots of emissions. We are conducting ongoing work on how to integrate the two measurement techniques, as well as how the empirical measurements compare with

  2. Study of plasma modified-PTFE for biological applications: relationship between protein resistant properties, plasma treatment, surface composition and surface roughness

    PubMed Central

    Vandencasteele, Nicolas; Nisol, Bernard; Viville, Pascal; Lazzaroni, Roberto; Castner, David G.; Reniers, François

    2013-01-01

    PTFE samples were treated by low-pressure, O2 RF plasmas. The adsorption of BSA was used as a probe for the protein resistant properties. The exposure of PTFE to an O2 plasma leads to an increase in the chamber pressure. OES reveals the presence of CO, CO2 and F in the gas phase, indicating a strong etching of the PTFE surface by the O2 plasma. Furthermore, the high resolution C1s spectrum shows the appearance of CF3, CF and C-CF components in addition to the CF2 component, which is consistent with etching of the PTFE surface. WCA as high as 160° were observed, indicating a superhydrophobic behaviour. AFM Images of surfaces treated at high plasma power showed a increase in roughness. Lower amounts of BSA adsorption were detected on high power, O2 plasma-modified PTFE samples compared to low power, oxygen plasma-modified ones. PMID:24795545

  3. Wear-resistant and electromagnetic absorbing behaviors of oleic acid post-modified ferrite-filled epoxy resin composite coating

    NASA Astrophysics Data System (ADS)

    Wang, Wenjie; Zang, Chongguang; Jiao, Qingjie

    2015-03-01

    The post-modified Mn-Zn ferrite was prepared by grafting oleic acid on the surface of Mn-Zn ferrite to inhibit magnetic nanoparticle aggregation. Fourier Transform Infrared (FT-IR) spectroscopy was used to characterize the particle surfaces. The friction and electromagnetic absorbing properties of a thin coating fabricated by dispersing ferrite into epoxy resin (EP) were investigated. The roughness of the coating and water contact angle were measured using the VEECO and water contact angle meter. Friction tests were conducted using a stainless-steel bearing ball and a Rockwell diamond tip, respectively. The complex permittivity and complex permeability of the composite coating were studied in the low frequency (10 MHz-1.5 GHz). Surface modified ferrites are found to improve magnetic particles dispersion in EP resulting in significant compatibility between inorganic and organic materials. Results also indicate that modified ferrite/EP coatings have a lower roughness average value and higher water contact angle than original ferrite/EP coatings. The enhanced tribological properties of the modified ferrite/EP coatings can be seen from the increased coefficient value. The composite coatings with modified ferrite are observed to exhibit better reflection loss compared with the coatings with original ferrite.

  4. Phosphoethanolamine Transferase LptA in Haemophilus ducreyi Modifies Lipid A and Contributes to Human Defensin Resistance In Vitro

    PubMed Central

    Trombley, Michael P.; Post, Deborah M. B.; Rinker, Sherri D.; Reinders, Lorri M.; Fortney, Kate R.; Zwickl, Beth W.; Janowicz, Diane M.; Baye, Fitsum M.; Katz, Barry P.; Spinola, Stanley M.; Bauer, Margaret E.

    2015-01-01

    Haemophilus ducreyi resists the cytotoxic effects of human antimicrobial peptides (APs), including α-defensins, β-defensins, and the cathelicidin LL-37. Resistance to LL-37, mediated by the sensitive to antimicrobial peptide (Sap) transporter, is required for H. ducreyi virulence in humans. Cationic APs are attracted to the negatively charged bacterial cell surface. In other gram-negative bacteria, modification of lipopolysaccharide or lipooligosaccharide (LOS) by the addition of positively charged moieties, such as phosphoethanolamine (PEA), confers AP resistance by means of electrostatic repulsion. H. ducreyi LOS has PEA modifications at two sites, and we identified three genes (lptA, ptdA, and ptdB) in H. ducreyi with homology to a family of bacterial PEA transferases. We generated non-polar, unmarked mutants with deletions in one, two, or all three putative PEA transferase genes. The triple mutant was significantly more susceptible to both α- and β-defensins; complementation of all three genes restored parental levels of AP resistance. Deletion of all three PEA transferase genes also resulted in a significant increase in the negativity of the mutant cell surface. Mass spectrometric analysis revealed that LptA was required for PEA modification of lipid A; PtdA and PtdB did not affect PEA modification of LOS. In human inoculation experiments, the triple mutant was as virulent as its parent strain. While this is the first identified mechanism of resistance to α-defensins in H. ducreyi, our in vivo data suggest that resistance to cathelicidin LL-37 may be more important than defensin resistance to H. ducreyi pathogenesis. PMID:25902140

  5. The electrical resistivity structure of lithosphere across the Dharwar craton nucleus and Coorg block of South Indian shield: Evidence of collision and modified and preserved lithosphere

    NASA Astrophysics Data System (ADS)

    Abdul Azeez, K. K.; Veeraswamy, K.; Gupta, Arvind K.; Babu, Narendra; Chandrapuri, Sateesh; Harinarayana, T.

    2015-10-01

    Magnetotelluric-derived two-dimensional lithospheric resistivity structure of the western Dharwar craton (WDC) and adjoining Coorg block indicates isolated low-resistivity zones in the crust and three striking upper mantle conductive features within the highly resistive Archean lithosphere. The crustal conductors in the WDC show good spatial correlation with the exposed supracrustal rocks conformable with the relic schist belt channels having conductive mineral grains. Conductive zones within the Coorg crust might be related to the relatively young (933 Ma) metamorphic processes in the area and/or possible fluids derived from the Cretaceous passage of Reunion plume in the proximity of Coorg area. A near-vertical conductive structure extending from the lower crust into the upper mantle coincides with the transition zone between Coorg and WDC. This is interpreted as the suture zone between the two tectonic blocks and provides evidence for the individuality of the two Archean terrains. An anomalous upper mantle conductive zone found beneath the craton nucleus may indicate a modified cratonic lithosphere. This could have been derived due to the collision between Coorg and WDC and possibly survived by the subsequent multiple episodes of melt and fluid infiltration processes experienced in the region. Thick (~190 km) and preserved lithosphere is mapped at the eastern segment of WDC. Resistive lithosphere of ~125 km thickness is imaged for the Coorg block.

  6. Co-expression of a modified maize ribosome-inactivating protein and a rice basic chitinase gene in transgenic rice plants confers enhanced resistance to sheath blight.

    PubMed

    Kim, Ju-Kon; Jang, In-Cheol; Wu, Ray; Zuo, Wei-Neng; Boston, Rebecca S; Lee, Yong-Hwan; Ahn, Il-Pyung; Nahm, Baek Hie

    2003-08-01

    Chitinases, beta-1,3-glucanases, and ribosome-inactivating proteins are reported to have antifungal activity in plants. With the aim of producing fungus-resistant transgenic plants, we co-expressed a modified maize ribosome-inactivating protein gene, MOD1, and a rice basic chitinase gene, RCH10, in transgenic rice plants. A construct containing MOD1 and RCH10 under the control of the rice rbcS and Act1 promoters, respectively, was co-transformed with a plasmid containing the herbicide-resistance gene bar as a selection marker into rice by particle bombardment. Several transformants analyzed by genomic Southern-blot hybridization demonstrated integration of multiple copies of the foreign gene into rice chromosomes. Immunoblot experiments showed that MOD1 formed approximately 0.5% of the total soluble protein in transgenic leaves. RCH10 expression was examined using the native polyacrylamide-overlay gel method, and high RCH10 activity was observed in leaf tissues where endogenous RCH10 is not expressed. R1 plants were analyzed in a similar way, and the Southern-blot patterns and levels of transgene expression remained the same as in the parental line. Analysis of the response of R2 plants to three fungal pathogens of rice, Rhizoctonia solani, Bipolaris oryzae, and Magnaporthe grisea, indicated statistically significant symptom reduction only in the case of R. solani (sheath blight). The increased resistance co-segregated with herbicide tolerance, reflecting a correlation between the resistance phenotype and transgene expression. PMID:12885168

  7. Intergrated palmer amaranth management in glufosinate-resistant cotton: I. Soil-inversion, high-residue cover crops and herbicide regimes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amaranthus control in cotton can be difficult with the loss of glyphosate efficacy, especially in conservation tillage cropping systems. Research was conduction from 2006 to 2008 at EV Smith Research Center, Shorter, Alabama, to determine the level of glyphosate susceptible amaranthus control provi...

  8. Identification of a chitinase modifying protein from Fusarium verticillioides: truncation of a host resistance protein by a fungalysin metalloprotease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chitinase modifying proteins (cmps) are proteases, secreted by fungal pathogens, which truncate the plant class IV chitinases ChitA and ChitB during maize ear rot. Cmp activity has been characterized for Bipolaris zeicola and Stenocarpella maydis, but the identities of the proteases are not known. H...

  9. Public Acceptance of Plant Biotechnology and GM Crops.

    PubMed

    Lucht, Jan M

    2015-08-01

    A wide gap exists between the rapid acceptance of genetically modified (GM) crops for cultivation by farmers in many countries and in the global markets for food and feed, and the often-limited acceptance by consumers. This review contrasts the advances of practical applications of agricultural biotechnology with the divergent paths-also affecting the development of virus resistant transgenic crops-of political and regulatory frameworks for GM crops and food in different parts of the world. These have also shaped the different opinions of consumers. Important factors influencing consumer's attitudes are the perception of risks and benefits, knowledge and trust, and personal values. Recent political and societal developments show a hardening of the negative environment for agricultural biotechnology in Europe, a growing discussion-including calls for labeling of GM food-in the USA, and a careful development in China towards a possible authorization of GM rice that takes the societal discussions into account. New breeding techniques address some consumers' concerns with transgenic crops, but it is not clear yet how consumers' attitudes towards them will develop. Discussions about agriculture would be more productive, if they would focus less on technologies, but on common aims and underlying values. PMID:26264020

  10. PCSK7 Genotype Modifies Effect of a Weight-Loss Diet on 2-Year Changes of Insulin Resistance: The POUNDS LOST Trial

    PubMed Central

    Huang, Tao; Huang, Jinyan; Qi, Qibin; Li, Yanping; Bray, George A.; Rood, Jennifer; Sacks, Frank M.

    2015-01-01

    OBJECTIVE A common variant rs236918 in the PCSK7 gene has the strongest association with iron homeostasis and is related to insulin resistance. Dietary carbohydrate (CHO) modulates the genetic effect on insulin resistance. We examined whether 2-year weight-loss diets modify the effect of PCSK7 genetic variants on changes in fasting insulin levels and insulin resistance in a randomized, controlled trial. RESEARCH DESIGN AND METHODS Data were analyzed in the Preventing Overweight Using Novel Dietary Strategies (POUNDS LOST) trial, which is a randomized, controlled 2-year weight-loss trial using diets that differed in macronutrient proportions. PCSK7 rs236918 was genotyped in 730 overweight or obese adults (80% whites) in this trial. We assessed the progression in fasting insulin and glucose levels, and insulin resistance by genotypes. RESULTS During the 6-month weight-loss phase, the PCSK7 rs236918 G allele was significantly associated with greater decreases in fasting insulin levels in the high–dietary CHO group (P for interaction = 0.04), while the interaction for changes in HOMA-insulin resistance (HOMA-IR) (P for interaction = 0.06) did not reach significant levels in white subjects. The G allele was significantly associated with a greater decrease in fasting insulin levels and HOMA-IR in response to high dietary CHO levels (P = 0.02 and P = 0.03, respectively). From 6 months to 2 years (weight-regain phase), the interactions became attenuated due to the regaining of weight (P for interactions = 0.08 and 0.06, respectively). In addition, we observed similar and even stronger results in the whole-study samples from the trial. CONCLUSIONS Our data suggest that PCSK7 genotypes may interact with dietary CHO intake on changes in insulin sensitivity in the white Americans. PMID:25504030

  11. Impact of insect-resistant GM rice on pesticide use and farmers' health in China.

    PubMed

    Huang, JiKun; Hu, RuiFa; Qiao, FangBin; Yin, YanHong; Liu, HuaiJu; Huang, ZhuRong

    2015-05-01

    The economic benefits of insect-resistant genetically modified (GM) crops have been well documented, but the impact of such crops and the consequent reduction in pesticide use on farmers' health remains largely unknown. Through the analysis of the data collected from the physical examination from farmers in China, we show that GM rice significantly reduces pesticide use and the resultant not only visible but also invisible adverse effects on farmers' neurological, hematological, and electrolyte system. Hence, the commercialization of GM rice is expected to improve the health of farmers in developing countries, where pesticide application is necessary to mitigate crop loss. PMID:25576299

  12. Bt crops: predicting effects of escaped transgenes on the fitness of wild plants and their herbivores.

    PubMed

    Letourneau, Deborah K; Robinson, Gaden S; Hagen, Joy A

    2003-01-01

    One prominent concern about genetically modified crops is the possibility of environmental impacts from the movement of fitness-enhancing traits to wild plant populations. Decisions to deregulate Bt crops in the USA have relied strongly on arguments that these crops will not interbreed with wild relatives in the permitted growing regions. Limited attention therefore has been directed to analyses of the consequences of gene flow. To provide a transparent evaluation process for risks associated with insecticidal transgene escape, we crafted a series of questions designed to guide this aspect of the risk assessment. We then explored the current knowledge base available for answering such risk-related questions for three Bt crops (cotton, rapeseed, and rice). First, we generated a list of wild relatives of these crops. A definitive list of potential transgene recipients is not yet possible for some crops. Sufficient data are not available for some crops to eliminate certain related plant species from consideration of fertile hybrid formation, thus making lists for these crops subject to speculation. Second, we queried the HOSTS database (UK) to obtain a worldwide listing of lepidopteran species that feed on these crops and their wild relatives, and to determine the host range of the larvae. To our knowledge, this list of 502 lepidopteran species is the first such list published for these crops and wild crop relatives. Third, we used a data set maintained by the Canadian Forest Service to assess Bt toxin susceptibility for these lepidopterans. Only 3% of those species have been tested for susceptibility; and the literature suggests that generalizations about susceptibility among taxa are difficult due to the variability within families. Fourth, we consulted the literature to interpret what is known about the ability of lepidopterans to regulate plant fitness or invasiveness. We could not eliminate the possibility of ecological release due to plant resistance against

  13. Crop Rotation in Row Crop Production Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop rotation is a system of growing different kinds of crops in recurrent succession on the same land. Thus, in the strictest sense, crop rotation is more than just changing crops from year to year based on current economic situations. Rather, it is a long-term plan for soil and farm management. Cr...

  14. Radiation model for row crops: II. Model evaluation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Relatively few radiation transfer studies have considered the impact of varying vegetation cover that typifies row crops, and meth¬ods to account for partial row crop cover have not been well investigated. Our objective was to evaluate a widely used radiation model that was modified for row crops ha...

  15. Improvement of Sulphur Resistance of a Nickel-modified Catalytic Filter for Tar Removal from Biomass Gasification Gas

    SciTech Connect

    Zhang, Y.; Draelants, D.J.; Engelen, K.; Baron, G.V.

    2002-09-19

    This work focuses on the development of catalytic candle filters for the simultaneous removal of tars and particles from the biomass gasification gas at high temperature. An improvement of sulphur resistance of the nickel-activated catalytic filter was developed by the addition of CaO. The influences of preparation procedure of catalytic filter, the ratio of Ni/CaO and the loading of Ni and CaO on the performance of the catalytic filter were investigated.

  16. Structural Basis of Duplex Thermodynamic Stability and Enhanced Nuclease Resistance of 5'-C-Methyl Pyrimidine-Modified Oligonucleotides.

    PubMed

    Kel'in, Alexander V; Zlatev, Ivan; Harp, Joel; Jayaraman, Muthusamy; Bisbe, Anna; O'Shea, Jonathan; Taneja, Nate; Manoharan, Rajar M; Khan, Saeed; Charisse, Klaus; Maier, Martin A; Egli, Martin; Rajeev, Kallanthottathil G; Manoharan, Muthiah

    2016-03-18

    Although judicious use of chemical modifications has contributed to the success of nucleic acid therapeutics, poor systemic stability remains a major hurdle. The introduction of functional groups around the phosphate backbone can enhance the nuclease resistance of oligonucleotides (ONs). Here, we report the synthesis of enantiomerically pure (R)- and (S)-5'-C-methyl (C5'-Me) substituted nucleosides and their incorporation into ONs. These modifications generally resulted in a decrease in thermal stability of oligonucleotide (ON) duplexes in a manner dependent on the stereoconfiguration at C5' with greater destabilization characteristic of (R)-epimers. Enhanced stability against snake venom phosphodiesterase resulted from modification of the 3'-end of an ON with either (R)- or (S)-C5'-Me nucleotides. The (S)-isomers with different 2'-substituents provided greater resistance against 3'-exonucleases than the corresponding (R)-isomers. Crystal structure analyses of RNA octamers with (R)- or (S)-5'-C-methyl-2'-deoxy-2'-fluorouridine [(R)- or (S)-C5'-Me-2'-FU, respectively] revealed that the stereochemical orientation of the C5'-Me and the steric effects that emanate from the alkyl substitution are the dominant determinants of thermal stability and are likely molecular origins of resistance against nucleases. X-ray and NMR structural analyses showed that the (S)-C5'-Me epimers are spatially and structurally more similar to their natural 5' nonmethylated counterparts than the corresponding (R)-epimers. PMID:26940174

  17. a Modified Van Der Pauw Setup for Measuring the Resistivity and Thermopower of Thermoelectric Materials of Varying Thicknesses

    NASA Astrophysics Data System (ADS)

    Hitchcock, Dale; Waldrop, Spencer; Williams, Jared; Tritt, Terry M.

    2013-10-01

    In the investigation of thermoelectric (TE) materials as a practical, and efficient, means of power generation/ refrigeration nearly ninety percent of the possible high-efficient binary compounds have been evaluated. But only a few proved to be useful such as Bi2Te3 alloys, PbTe and SiGe to name the most important materials. Therefore, in order to expand the research of high-efficiency TE materials new compounds and methods of efficiency optimization must be explored. There currently exist a vast number of uninvestigated ternary and quaternary materials that could be potential high-efficiency thermoelectric materials. The device and methodology discussed herein deal with rapidly measuring both the electrical resistivity and the Seebeck coefficient of thermoelectric materials, at a set temperature of T ≈ 300 K. Using nontraditional resistivity measurements and rapid, room-temperature thermopower measurements, a reliable and time-efficient means of gauging the power factor (defined below) values of newly synthesized thermoelectric materials is achievable. Furthermore, the efficacy of the van der Pauw technique for measuring the resistivity of thermoelectric materials has been verified.

  18. Hyaluronic Acid-Modified Multifunctional Q-Graphene for Targeted Killing of Drug-Resistant Lung Cancer Cells.

    PubMed

    Luo, Yanan; Cai, Xiaoli; Li, He; Lin, Yuehe; Du, Dan

    2016-02-17

    Considering the urgent need to explore multifunctional drug delivery system for overcoming multidrug resistance, we prepared a new nanocarbon material Q-Graphene as a nanocarrier for killing drug-resistant lung cancer cells. Attributing to the introduction of hyaluronic acid and rhodamine B isothiocyanate (RBITC), the Q-Graphene-based drug delivery system was endowed with dual function of targeted drug delivery and fluorescence imaging. Additionally, doxorubicin (DOX) as a model drug was loaded on the surface of Q-Graphene via π-π stacking. Interestingly, the fluorescence of DOX was quenched by Q-Graphene due to its strong electron-accepting capability, and a significant recovery of fluorescence was observed, while DOX was released from Q-Graphene. Because of the RBITC labeling and the effect of fluorescence quenching/restoring of Q-Graphene, the uptake of nanoparticles and intracellular DOX release can be tracked. Overall, a highly promising multifunctional nanoplatform was developed for tracking and monitoring targeted drug delivery for efficiently killing drug-resistant cancer cells. PMID:26785717

  19. Modifying crops to increase cell wall digestibility.

    PubMed

    Jung, Hans-Joachim G; Samac, Deborah A; Sarath, Gautam

    2012-04-01

    Improving digestibility of roughage cell walls will improve ruminant animal performance and reduce loss of nutrients to the environment. The main digestibility impediment for dicotyledonous plants is highly lignified secondary cell walls, notably in stem secondary xylem, which become almost non-digestible. Digestibility of grasses is slowed severely by lignification of most tissues, but these cell walls remain largely digestible. Cell wall lignification creates an access barrier to potentially digestible wall material by rumen bacteria if cells have not been physically ruptured. Traditional breeding has focused on increasing total dry matter digestibility rather than cell wall digestibility, which has resulted in minimal reductions in cell wall lignification. Brown midrib mutants in some annual grasses exhibit small reductions in lignin concentration and improved cell wall digestibility. Similarly, transgenic approaches down-regulating genes in monolignol synthesis have produced plants with reduced lignin content and improved cell wall digestibility. While major reductions in lignin concentration have been associated with poor plant fitness, smaller reductions in lignin provided measurable improvements in digestibility without significantly impacting agronomic fitness. Additional targets for genetic modification to enhance digestibility and improve roughages for use as biofuel feedstocks are discussed; including manipulating cell wall polysaccharide composition, novel lignin structures, reduced lignin/polysaccharide cross-linking, smaller lignin polymers, enhanced development of non-lignified tissues, and targeting specific cell types. Greater tissue specificity of transgene expression will be needed to maximize benefits while avoiding negative impacts on plant fitness.cauliflower mosiac virus (CaMV) 35S promoter. PMID:22325867

  20. Modifying crops to increase cell wall digestibility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improving digestibility of roughage cell walls will improve ruminant animal performance and reduce loss of nutrients to the environment. The main digestibility impediment for dicotyledonous plants are highly lignified secondary cell walls, notably in stem secondary xylem, which become almost non-dig...

  1. Genetically Modified Crops Are Safe: Review

    MedlinePlus

    ... Gould likened the situation to how cellphones and laptop computers used to be completely separate devices. "Today, ... would be doing most of the things their laptop was doing back in 1996," he said. Bruce ...

  2. Genetically Modified Crops Are Safe: Review

    MedlinePlus

    ... human health by working their way into the soil and groundwater. The committee came to its conclusions ... Chassy, an emeritus professor of biochemistry and food science at the University of Illinois, told the Associated ...

  3. Silver-nanoparticles-modified biomaterial surface resistant to staphylococcus: new insight into the antimicrobial action of silver.

    PubMed

    Wang, Jiaxing; Li, Jinhua; Guo, Geyong; Wang, Qiaojie; Tang, Jin; Zhao, Yaochao; Qin, Hui; Wahafu, Tuerhongjiang; Shen, Hao; Liu, Xuanyong; Zhang, Xianlong

    2016-01-01

    Titanium implants are widely used clinically, but postoperative implant infection remains a potential severe complication. The purpose of this study was to investigate the antibacterial activity of nano-silver(Ag)-functionalized Ti surfaces against epidemic Staphylococcus from the perspective of the regulation of biofilm-related genes and based on a bacteria-cell co-culture study. To achieve this goal, two representative epidemic Staphylococcus strains, Staphylococcus epidermidis (S. epidermidis, RP62A) and Staphylococcus aureus (S. aureus, USA 300), were used, and it was found that an Ag-nanoparticle-modified Ti surface could regulate the expression levels of biofilm-related genes (icaA and icaR for S. epidermidis; fnbA and fnbB for S. aureus) to inhibit bacterial adhesion and biofilm formation. Moreover, a novel bacteria-fibroblast co-culture study revealed that the incorporation of Ag nanoparticles on such a surface can help mammalian cells to survive, adhere and spread more successfully than Staphylococcus. Therefore, the modified surface was demonstrated to possess a good anti-infective capability against both sessile bacteria and planktonic bacteria through synergy between the effects of Ag nanoparticles and ion release. This work provides new insight into the antimicrobial action and mechanism of Ag-nanoparticle-functionalized Ti surfaces with bacteria-killing and cell-assisting capabilities and paves the way towards better satisfying the clinical needs. PMID:27599568

  4. Silver-nanoparticles-modified biomaterial surface resistant to staphylococcus: new insight into the antimicrobial action of silver

    PubMed Central

    Wang, Jiaxing; Li, Jinhua; Guo, Geyong; Wang, Qiaojie; Tang, Jin; Zhao, Yaochao; Qin, Hui; Wahafu, Tuerhongjiang; Shen, Hao; Liu, Xuanyong; Zhang, Xianlong

    2016-01-01

    Titanium implants are widely used clinically, but postoperative implant infection remains a potential severe complication. The purpose of this study was to investigate the antibacterial activity of nano-silver(Ag)-functionalized Ti surfaces against epidemic Staphylococcus from the perspective of the regulation of biofilm-related genes and based on a bacteria-cell co-culture study. To achieve this goal, two representative epidemic Staphylococcus strains, Staphylococcus epidermidis (S. epidermidis, RP62A) and Staphylococcus aureus (S. aureus, USA 300), were used, and it was found that an Ag-nanoparticle-modified Ti surface could regulate the expression levels of biofilm-related genes (icaA and icaR for S. epidermidis; fnbA and fnbB for S. aureus) to inhibit bacterial adhesion and biofilm formation. Moreover, a novel bacteria-fibroblast co-culture study revealed that the incorporation of Ag nanoparticles on such a surface can help mammalian cells to survive, adhere and spread more successfully than Staphylococcus. Therefore, the modified surface was demonstrated to possess a good anti-infective capability against both sessile bacteria and planktonic bacteria through synergy between the effects of Ag nanoparticles and ion release. This work provides new insight into the antimicrobial action and mechanism of Ag-nanoparticle-functionalized Ti surfaces with bacteria-killing and cell-assisting capabilities and paves the way towards better satisfying the clinical needs. PMID:27599568

  5. Safety assessment and public concerns for genetically modified food products: the Japanese experience.

    PubMed

    Hino, Akihiro

    2002-01-01

    The recombinant DNA (rDNA) technique is expected to bring about great progress in the improvement of breeding technology and the development of new plant varieties showing high quality and high yield, such as those with excellent pest and disease resistance, those with environmental stress tolerance, and so forth. In the United States and Canada, many genetically modified (GM) crop plants were commercialized as early as 1994. In Japan, 35 transgenic crop plants, such as herbicide tolerant soybean, cotton, and canola, and insect-resistant corn, cotton, and potatos, were authorized and considered marketable until April 2001. The general public, however, is not familiar with rDNA technology, and some people seem to feel uncomfortable with biotechnology, frequently because of the difficulty of the technology and lacking of sufficient information. New labeling systems were initiated in April 2001 in Japan to provide information regarding the use of GM crops as raw material. PMID:11890464

  6. Double Methotrexate-Modified Neuropeptide Y Analogues Express Increased Toxicity and Overcome Drug Resistance in Breast Cancer Cells.

    PubMed

    Böhme, David; Krieghoff, Jan; Beck-Sickinger, Annette G

    2016-04-14

    Bioconjugates containing the neuropeptide Y (NPY) analogue [F(7),P(34)]-NPY as targeting moiety are able to deliver toxic agents specifically to breast cancer cells that overexpress the human Y1-receptor (hY1R). To increase their activity, multiple toxophores can be attached to one peptide. Herein, synthesis and characterization of [F(7),P(34)]-NPY conjugates containing two methotrexate (MTX) molecules are presented. First, carboxytetramethylrhodamine was linked to [F(7),P(34)]-NPY by amide or enzymatic linkage. The conjugate containing the enzymatic cleavage site showed high extracellular stability and fast intracellular release. Then, MTX was introduced at positions four and 22 of [F(7),P(34)]-NPY, connected by enzymatic or amide linkage. The toxicity of the analogues on breast cancer cells was hY1R-mediated and dependent on the used linkage and amount of toxophores. Furthermore, conjugates revealed higher potency than MTX on MTX-resistant cells. These results emphasize that peptide-drug conjugates can overcome drug resistance and that the attachment of multiple cleavable toxophores enhances the efficiency of this smart delivery system. PMID:26985967

  7. Effects of GM crops on non-target organisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop genetically engineered to provide resistance to specific groups of insect pests have been adopted by millions of growers throughout the world. GM crops have become important tools in crop production and protection in many countries and contribute significantly to overall IPM programs. There, ...

  8. Atypical Clinical Presentation of a Newer Generation Anti-Fungal Drug-Resistant Fusarium Infection After a Modified Multi-Visceral Transplant.

    PubMed

    Kandeel, Ahmed; Abu-Elmagd, Kareem; Spinner, Michael; Khanna, Ajai; Hashimoto, Koji; Fujiki, Masato; Parsi, Mansiur; Bennett, Ana; El-Gazzaz, Galal; Abd-Elaal, Ahmed

    2015-01-01

    BACKGROUND Fusarium spp. infections have become an emerging and lethal threat to the immunocompromised patient population, especially those with neutropenia. Recently there have been increased reports in solid organ transplant recipients. Presentation is commonly as soft tissue infections several months post-transplant. With high morbidity and mortality, efficacious antifungal therapy is essential. This remains challenging with limited data and no established clinical breakpoints defined. CASE REPORT We report on a modified multi-visceral transplant patient that developed a Fusarium infection only 7 weeks post-transplant in the native hard palate and esophagus, without any soft tissue lesions, which persisted despite aggressive combination treatment with amphotericin B lipid complex and voriconazole. CONCLUSIONS Fusarium spp. infection in solid organ transplant is a significant challenge without clear diagnostic clinical indicators of infection, or specific time of onset, in addition to possible emergence of a more aggressive drug-resistant strain. PMID:26334671

  9. Remarkable enhancement in the Kapitza resistance and electron potential barrier of chemically modified In2O3(ZnO)9 natural superlattice interfaces.

    PubMed

    Liang, Xin

    2015-11-28

    Superlattice interfaces can efficiently scatter phonons and filter low-energy electrons, thereby reducing the thermal conductivity to the "alloy limit" of crystalline solids and increasing the Seebeck coefficient substantially. In this paper, we report a two-fold reduction in the thermal conductivity and an improvement of about 170% in the Seebeck coefficient of an existing In2O3(ZnO)9 superlattice by chemically modifying the interface with small additions of aluminum. Using a classical model for the interface transport, we attribute such significant changes to the increase in both the Kapitza (thermal) resistance and the electron potential barrier height of the InO2(-) superlattice interfaces that are modified by Al(3+). The present work opens a new avenue of research showing that the superlattice interfaces can be chemically tuned for specific properties, which can be investigated in both experimental and computational ways, and also suggests a new route for material design for applications in areas like thermoelectrics. PMID:26477746

  10. Genetic engineering of the green alga Chlorella zofingiensis: a modified norflurazon-resistant phytoene desaturase gene as a dominant selectable marker.

    PubMed

    Liu, Jin; Sun, Zheng; Gerken, Henri; Huang, Junchao; Jiang, Yue; Chen, Feng

    2014-06-01

    The unicellular green alga Chlorella zofingiensis has been proposed as a promising producer of natural astaxanthin, a commercially important ketocarotenoid. But the genetic toolbox for this alga is not available. In the present study, an efficient transformation system was established for C. zofingiensis. The transformation system utilized a modified norflurazon-resistant phytoene desaturase (PDS-L516F, with an leucine-phenylalanine change at position 516) as the selectable marker. Three promoters from endogenous PDS, nitrate reductase (NIT), and ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (RBCS) genes were tested, with the RBCS promoter demonstrating the highest transformation efficiency. Inclusion of the first intron of the PDS gene further enhanced the efficiency by 91 %. Both particle bombardment and electroporation methods were examined, and the latter gave a fourfold higher transformation efficiency. The introduction of PDS-L516F, which exhibited a 33 % higher desaturation activity than the unaltered enzyme, enabled C. zofingiensis to produce 32.1 % more total carotenoids (TCs) and 54.1 % more astaxanthin. The enhanced accumulation of astaxanthin in transformants was revealed to be related to the increase in the transcripts of PDS, β-carotenoid ketolase (BKT), and hydroxylase (CHYb) genes. Our study clearly shows that the modified PDS gene is a dominant selectable marker for the transformation of C. zofingiensis and possibly for the genetic engineering of the carotenoid biosynthetic pathway. In addition, the engineered C. zofingiensis might serve as an improved source of natural astaxanthin. PMID:24584513

  11. The effect of substrate bias voltages on impact resistance of CrAlN coatings deposited by modified ion beam enhanced magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Chunyan, Yu; Linhai, Tian; Yinghui, Wei; Shebin, Wang; Tianbao, Li; Bingshe, Xu

    2009-01-01

    CrAlN coatings were deposited on silicon and AISI H13 steel substrates using a modified ion beam enhanced magnetron sputtering system. The effect of substrate negative bias voltages on the impact property of the CrAlN coatings was studied. The X-ray diffraction (XRD) data show that all CrAlN coatings were crystallized in the cubic NaCl B1 structure, with the (1 1 1), (2 0 0) (2 2 0) and (2 2 2) diffraction peaks observed. Two-dimensional surface morphologies of CrAlN coatings were investigated by atomic force microscope (AFM). The results show that with increasing substrate bias voltage the coatings became more compact and denser, and the microhardness and fracture toughness of the coatings increased correspondingly. In the dynamic impact resistance tests, the CrAlN coatings displayed better impact resistance with the increase of bias voltage, due to the reduced emergence and propagation of the cracks in coatings with a very dense structure and the increase of hardness and fracture toughness in coatings.

  12. Mutant p53-R273H mediates cancer cell survival and anoikis resistance through AKT-dependent suppression of BCL2-modifying factor (BMF)

    PubMed Central

    Tan, B S; Tiong, K H; Choo, H L; Fei-Lei Chung, F; Hii, L-W; Tan, S H; Yap, I KS; Pani, S; Khor, N TW; Wong, S F; Rosli, R; Cheong, S-K; Leong, C-O

    2015-01-01

    p53 is the most frequently mutated tumor-suppressor gene in human cancers. Unlike other tumor-suppressor genes, p53 mutations mainly occur as missense mutations within the DNA-binding domain, leading to the expression of full-length mutant p53 protein. Mutant p53 proteins not only lose their tumor-suppressor function, but may also gain new oncogenic functions and promote tumorigenesis. Here, we showed that silencing of endogenous p53-R273H contact mutant, but not p53-R175H conformational mutant, reduced AKT phosphorylation, induced BCL2-modifying factor (BMF) expression, sensitized BIM dissociation from BCL-XL and induced mitochondria-dependent apoptosis in cancer cells. Importantly, cancer cells harboring endogenous p53-R273H mutant were also found to be inherently resistant to anoikis and lack BMF induction following culture in suspension. Underlying these activities is the ability of p53-R273H mutant to suppress BMF expression that is dependent on constitutively active PI3K/AKT signaling. Collectively, these findings suggest that p53-R273H can specifically drive AKT signaling and suppress BMF expression, resulting in enhanced cell survivability and anoikis resistance. These findings open the possibility that blocking of PI3K/AKT will have therapeutic benefit in mutant p53-R273H expressing cancers. PMID:26181206

  13. Combined effects of gamma irradiation and modified atmosphere packaging on bacterial resistance in grated carrots ( Daucus carota)

    NASA Astrophysics Data System (ADS)

    Lacroix, M.; Lafortune, R.

    2004-09-01

    The present study was conducted to evaluate the efficiency of gamma irradiation combined with modified atmosphere packaging as an alternative treatment to ensure the innocuity and the shelf life extension of pre-cured vegetables. Grated carrots were inoculated with Escherichia coli (10 6 CFU/g) and packed under air or under MAP condition (60% O 2, 30% CO 2 and 10% N 2). The packages were then, gamma irradiated at doses from 0.15 to 0.9 kGy and stored at 4±1°C. E. coli counts were periodically evaluated during 50 days of storage. Results showed that at day 1, an irradiation treatment at a dose of 0.15 kGy reduced by 3 and 4 log the microbial level representing a level of 3 and 2 log CFU/g when samples were irradiated under air and under MAP respectively. However, a level of 3 log CFU/g was detected in both treated samples after 7 days of storage. When samples were irradiated at doses ⩾0.3 kGy no E.coli were detected during the whole storage in samples treated under MAP. However, when samples were treated under air, a level of 1-2 log CFU/g of E.coli was detected after 5 days of storage.

  14. Evolutionary ecology of insect adaptation to Bt crops

    PubMed Central

    Carrière, Yves; Crowder, David W; Tabashnik, Bruce E

    2010-01-01

    Transgenic crops producing Bacillus thuringiensis (Bt) toxins are used worldwide to control major pests of corn and cotton. Development of strategies to delay the evolution of pest resistance to Bt crops requires an understanding of factors affecting responses to natural selection, which include variation in survival on Bt crops, heritability of resistance, and fitness advantages associated with resistance mutations. The two main strategies adopted for delaying resistance are the refuge and pyramid strategies. Both can reduce heritability of resistance, but pyramids can also delay resistance by reducing genetic variation for resistance. Seasonal declines in the concentration of Bt toxins in transgenic cultivars, however, can increase the heritability of resistance. The fitness advantages associated with resistance mutations can be reduced by agronomic practices, including increasing refuge size, manipulating refuges to increase fitness costs, and manipulating Bt cultivars to reduce fitness of resistant individuals. Manipulating costs and fitness of resistant individuals on transgenic insecticidal crops may be especially important for thwarting evolution of resistance in haplodiploid and parthenogenetic pests. Field-evolved resistance to Bt crops in only five pests during the last 14 years suggests that the refuge strategy has successfully delayed resistance, but the accumulation of resistant pests could accelerate. PMID:25567947

  15. Multifunctional polyamidoamine-modified selenium nanoparticles dual-delivering siRNA and cisplatin to A549/DDP cells for reversal multidrug resistance.

    PubMed

    Zheng, Wenjing; Cao, Chengwen; Liu, Yanan; Yu, Qianqian; Zheng, Chuping; Sun, Dongdong; Ren, Xiaofan; Liu, Jie

    2015-01-01

    Multidrug resistance (MDR) is a major barrier against effective cancer treatment. Dual-delivering a therapeutic small interfering RNA (siRNA) and chemotherapeutic agents has been developed to reverse drug resistance in tumor cells. In this study, amine-terminated generation 5 polyamidoamine (PAMAM) dendrimers (G5.NH2)-modified selenium nanoparticles (G5@Se NP) were synthesized for the systemic dual-delivery of mdr1 siRNA and cisplatin (cis-diamminedichloroplatinum-(II), DDP), which was demonstrated to enhance siRNA loading, releasing efficiency and gene-silencing efficacy. When the mdr1 siRNA was conjugated with G5@Se NP via electrostatic interaction, a significant down-regulation of P-glycoprotein and multidrug resistance-associated protein expression was observed; G5@Se-DDP-siRNA arrested A549/DDP cells at G1 phase and led to enhanced cytotoxicity in A549/DDP cells through induction of apoptosis involving the AKT and ERK signaling pathways. Interestingly, G5@Se-DDP NP were much less reactive than DDP in the reactions with both MT and GSH, indicating that loading of DDP in a nano-delivery system could effectively prevent cell detoxification. Furthermore, animal studies demonstrated that the new delivery system of G5@Se-DDP-siRNA significantly enhanced the anti-tumor effect on tumor-bearing nude mice, with no appreciable abnormality in the major organs. These results suggest that G5@Se NP could be a potential platform to combine chemotherapy and gene therapy technology in the treatment of human disease. PMID:25204523

  16. RNAi-mediated resistance to viruses in genetically engineered plants.

    PubMed

    Ibrahim, Abdulrazak B; Aragão, Francisco J L

    2015-01-01

    RNA interference (RNAi) has emerged as a leading technology in designing genetically modified crops engineered to resist viral infection. The last decades have seen the development of a large number of crops whose inherent posttranscriptional gene silencing mechanism has been exploited to target essential viral genes through the production of dsRNA that triggers an endogenous RNA-induced silencing complex (RISC), leading to gene silencing in susceptible viruses conferring them with resistance even before the onset of infection. Selection and breeding events have allowed for establishing this highly important agronomic trait in diverse crops. With improved techniques and the availability of new data on genetic diversity among several viruses, significant progress is being made in engineering plants using RNAi with the release of a number of commercially available crops. Biosafety concerns with respect to consumption of RNAi crops, while relevant, have been addressed, given the fact that experimental evidence using miRNAs associated with the crops shows that they do not pose any health risk to humans and animals. PMID:25740357

  17. Functional diversity of staphylinid beetles (Coleoptera: Staphylinidae) in maize fields: testing the possible effect of genetically modified, insect resistant maize.

    PubMed

    Svobodová, Z; Skoková Habuštová, O; Boháč, J; Sehnal, F

    2016-08-01

    Staphylinid beetles are recommended bioindicators for the pre-market environmental risk assessment of genetically modified (GM) insect protected maize expressing the Cry3Bb1 toxin. Our multiannual study is a unique European analysis of a staphylinid community within a 14 ha maize field. GM maize, its near-isogenic hybrid (with or without insecticide treatment), and two other reference hybrids were each grown in five 0.5 ha plots. The opportunity for exposure to Cry toxin from plant residues ploughed into the soil was shown by the presence of saprophagous dipteran larvae that are common prey of predatory staphylinid species and hosts of the parasitoid species. 2587 individuals belonging to 77 staphylinid species were sampled using pitfall traps. Lesteva longoelytrata (31%), Oxypoda acuminata (12%), Aloconota sulcifrons (8%) and Anotylus rugosus (7%) were the most abundant beetles in the field. Bionomics, food specialization, temperature requirements and size group were assigned for 25 most common species. These traits determine the occurrence of staphylinid beetles in the field, the food sources they could utilize and thus also their likely contact with the Cry3Bb1 toxin. Statistical analysis of activity abundance, Rao indices and multivariate analysis of distribution of particular categories of functional traits in the field showed negligible effects of the experimental treatments, including the GM maize, upon the staphylinid community. Staphylinid beetles represent a considerably diverse part of epigeic field fauna with wide food specialization; these features render them suitable for the assessment of environmental safety of GM insect protected maize. However, the availability of prey and the presence of particular staphylinid species and their abundance are highly variable; this complicates the interpretation of the results. PMID:26781035

  18. Evolution of New Disease Specificity at a Single Resistance Locus in a Crop-Weed Complex: Reconstitution of the Lr21 Gene in Wheat.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leaf-rust resistance gene Lr21, present in modern varieties of hexaploid wheat, originated in goatgrass Aegilops tauschii Coss., the D genome donor of wheat. The goatgrass donor was collected in Iran where it grows as a weed in wheat fields as part of the native agricultural ecosystem. In order to ...

  19. Simulating Stochastic Crop Management in Cropping Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction -- Crop simulation models are uniquely suitable for examining long term crop responses to environmental variability due to changes in climate or other factors. Long-term studies typically emphasize variability related to weather conditions; certain weather-dependent cropping practices m...

  20. Evaluation of spring wheat and barley crop calender models for the 1979 crop year

    NASA Technical Reports Server (NTRS)

    Nazare, C. V.; Carnes, J. G. (Principal Investigator)

    1981-01-01

    During the Large Area Crop Inventory Experiment, spring wheat planting date and crop development stage estimates based on historical normals were improved by the use of the Feyerherm planting date and Robertson spring wheat crop calendar models. The Supporting Research Crop Calendar Project element modified the Robertson model to reduce bias at cardinal growth stages within the growing season. These models were tested in 1980 along with a state-of-the-art barley model (Williams) against a ground-truth data set from 49 calendar year 1979 segments in the U.S. Great Plains spring wheat and barley region.

  1. The order of concurrent endurance and resistance exercise modifies mTOR signaling and protein synthesis in rat skeletal muscle.

    PubMed

    Ogasawara, Riki; Sato, Koji; Matsutani, Kenji; Nakazato, Koichi; Fujita, Satoshi

    2014-05-15

    Concurrent training, a combination of endurance (EE) and resistance exercise (RE) performed in succession, may compromise the muscle hypertrophic adaptations induced by RE alone. However, little is known about the molecular signaling interactions underlying the changes in skeletal muscle adaptation during concurrent training. Here, we used an animal model to investigate whether EE before or after RE affects the molecular signaling associated with muscle protein synthesis, specifically the interaction between RE-induced mammalian target of rapamycin complex 1 (mTORC1) signaling and EE-induced AMP-activated protein kinase (AMPK) signaling. Male Sprague-Dawley rats were divided into five groups: an EE group (treadmill, 25 m/min, 60 min), an RE group (maximum isometric contraction via percutaneous electrical stimulation for 3 × 10 s, 5 sets), an EE before RE group, an EE after RE group, and a nonexercise control group. Phosphorylation of p70S6K, a marker of mTORC1 activity, was significantly increased 3 h after RE in both the EE before RE and EE after RE groups, but the increase was smaller in latter. Furthermore, protein synthesis was greatly increased 6 h after RE in the EE before RE group. Increases in the phosphorylation of AMPK and Raptor were observed only in the EE after RE group. Akt and mTOR phosphorylation were increased in both groups, with no between-group differences. Our results suggest that the last bout of exercise dictates the molecular responses and that mTORC1 signaling induced by any prior bout of RE may be downregulated by a subsequent bout of EE. PMID:24691029

  2. Genetically Modified Foods and Social Concerns

    PubMed Central

    Maghari, Behrokh Mohajer; Ardekani, Ali M.

    2011-01-01

    Biotechnology is providing us with a wide range of options for how we can use agricultural and commercial forestry lands. The cultivation of genetically modified (GM) crops on millions of hectares of lands and their injection into our food chain is a huge global genetic experiment involving all living beings. Considering the fast pace of new advances in production of genetically modified crops, consumers, farmers and policymakers worldwide are challenged to reach a consensus on a clear vision for the future of world food supply. The current food biotechnology debate illustrates the serious conflict between two groups: 1) Agri-biotech investors and their affiliated scientists who consider agricultural biotechnology as a solution to food shortage, the scarcity of environmental resources and weeds and pests infestations; and 2) independent scientists, environmentalists, farmers and consumers who warn that genetically modified food introduces new risks to food security, the environment and human health such as loss of biodiversity; the emergence of superweeds and superpests; the increase of antibiotic resistance, food allergies and other unintended effects. This article reviews major viewpoints which are currently debated in the food biotechnology sector in the world. It also lays the ground-work for deep debate on benefits and risks of Biotech-crops for human health, ecosystems and biodiversity. In this context, although some regulations exist, there is a need for continuous vigilance for all countries involved in producing genetically engineered food to follow the international scientific bio-safety testing guidelines containing reliable pre-release experiments and post-release track of transgenic plants to protect public health and avoid future environmental harm. PMID:23408723

  3. Genetically modified foods and social concerns.

    PubMed

    Maghari, Behrokh Mohajer; Ardekani, Ali M

    2011-07-01

    Biotechnology is providing us with a wide range of options for how we can use agricultural and commercial forestry lands. The cultivation of genetically modified (GM) crops on millions of hectares of lands and their injection into our food chain is a huge global genetic experiment involving all living beings. Considering the fast pace of new advances in production of genetically modified crops, consumers, farmers and policymakers worldwide are challenged to reach a consensus on a clear vision for the future of world food supply. The current food biotechnology debate illustrates the serious conflict between two groups: 1) Agri-biotech investors and their affiliated scientists who consider agricultural biotechnology as a solution to food shortage, the scarcity of environmental resources and weeds and pests infestations; and 2) independent scientists, environmentalists, farmers and consumers who warn that genetically modified food introduces new risks to food security, the environment and human health such as loss of biodiversity; the emergence of superweeds and superpests; the increase of antibiotic resistance, food allergies and other unintended effects. This article reviews major viewpoints which are currently debated in the food biotechnology sector in the world. It also lays the ground-work for deep debate on benefits and risks of Biotech-crops for human health, ecosystems and biodiversity. In this context, although some regulations exist, there is a need for continuous vigilance for all countries involved in producing genetically engineered food to follow the international scientific bio-safety testing guidelines containing reliable pre-release experiments and post-release track of transgenic plants to protect public health and avoid future environmental harm. PMID:23408723

  4. Frequency of resistance to Bacillus thuringiensis in field populations of pink bollworm

    PubMed Central

    Tabashnik, Bruce E.; Patin, Amanda L.; Dennehy, Timothy J.; Liu, Yong-Biao; Carrière, Yves; Sims, Maria A.; Antilla, Larry

    2000-01-01

    Strategies for delaying pest resistance to genetically modified crops that produce Bacillus thuringiensis (Bt) toxins are based primarily on theoretical models. One key assumption of such models is that genes conferring resistance are rare. Previous estimates for lepidopteran pests targeted by Bt crops seem to meet this assumption. We report here that the estimated frequency of a recessive allele conferring resistance to Bt toxin Cry1Ac was 0.16 (95% confidence interval = 0.05–0.26) in strains of pink bollworm (Pectinophora gossypiella) derived from 10 Arizona cotton fields during 1997. Unexpectedly, the estimated resistance allele frequency did not increase from 1997 to 1999 and Bt cotton remained extremely effective against pink bollworm. These results demonstrate that the assumptions and predictions of resistance management models must be reexamined. PMID:11087854

  5. Public Acceptance of Plant Biotechnology and GM Crops

    PubMed Central

    Lucht, Jan M.

    2015-01-01

    A wide gap exists between the rapid acceptance of genetically modified (GM) crops for cultivation by farmers in many countries and in the global markets for food and feed, and the often-limited acceptance by consumers. This review contrasts the advances of practical applications of agricultural biotechnology with the divergent paths—also affecting the development of virus resistant transgenic crops—of political and regulatory frameworks for GM crops and food in different parts of the world. These have also shaped the different opinions of consumers. Important factors influencing consumer’s attitudes are the perception of risks and benefits, knowledge and trust, and personal values. Recent political and societal developments show a hardening of the negative environment for agricultural biotechnology in Europe, a growing discussion—including calls for labeling of GM food—in the USA, and a careful development in China towards a possible authorization of GM rice that takes the societal discussions into account. New breeding techniques address some consumers’ concerns with transgenic crops, but it is not clear yet how consumers’ attitudes towards them will develop. Discussions about agriculture would be more productive, if they would focus less on technologies, but on common aims and underlying values. PMID:26264020

  6. Bacillus thuringiensis (Bt) transgenic crop: an environment friendly insect-pest management strategy.

    PubMed

    Kumar, Suresh; Chandra, Amaresh; Pandey, K C

    2008-09-01

    Introduction of DDT (dichloro-diphenyl-trichloroethane) and following move towards indiscriminate use of synthetic chemical insecticides led to the contamination of water and food sources, poisoning of non-target beneficial insects and development of insect-pests resistant to the chemical insecticides. Increased public concems about the adverse environmental effects of indiscriminate use of chemical insecticides prompted search of altemative methods for insect-pest control. One of the promising alternatives has been the use of biological control agents. There is well-documented history of safe application of Bt (B. thuringiensis, a gram positive soil bacterium) as effective biopesticides and a number of reports of expression of delta-endotoxin gene(s) in crop plants are available. Only a few insecticidal sprays are required on Bt transgenic crops, which not only save cost and time, but also reduce health risks. Insects exhibit remarkable ability to develop resistance to different insecticidal compounds, which raises concern about the unsystematic use of Bt transgenic technology also. Though resistance to Bt products among insect species under field conditions has been rare, laboratory studies show that insects are capable of developing high levels of resistance to one ormore Cry proteins. Now it is generally agreed that 'high-dose/refuge strategy' is the most promising and practical approach to prolong the effectiveness of Bt toxins. Although manybiosafety concerns, ethical and moral issues exist, area under Bt transgenic crops is rapidly increasing and they are cultivated on more than 32 million hectares world over Even after reservation of European Union (EU) for acceptance of geneticaly modified (GM) crops, 6 out of 25 countries have already adopted Bt crops and many otherindustrial countries will adopt Bt transgenic crops in near future. While the modem biotechnology has been recognized to have a great potential for the promotion of human well-being, adoption

  7. Current trends in Bt crops and their fate on associated microbial community dynamics: a review.

    PubMed

    Singh, Amit Kishore; Dubey, Suresh Kumar

    2016-05-01

    Cry protein expressing insect-resistant trait is mostly deployed to control major devastating pests and minimize reliance on the conventional pesticides. However, the ethical and environmental issues are the major constraints in their acceptance, and consequently, the cultivation of genetically modified (GM) crops has invited intense debate. Since root exudates of Bacillus thuringiensis (Bt) crops harbor the insecticidal protein, there is a growing concern about the release and accumulation of soil-adsorbed Cry proteins and their impact on non-target microorganisms and soil microbial processes. This review pertains to reports from the laboratory studies and field trials to assess the Bt toxin proteins in soil microbes and the processes determining the soil quality in conjunction with the existing hypothesis and molecular approaches to elucidate the risk posed by the GM crops. Ecological perturbations hinder the risk aspect of soil microbiota in response to GM crops. Therefore, extensive research based on in vivo and interpretation of results using high-throughput techniques such as NGS on risk assessment are imperative to evaluate the impact of Bt crops to resolve the controversy related to their commercialization. But more studies are needed on the risk associated with stacked traits. Such studies would strengthen our knowledge about the plant-microbe interactions. PMID:26560114

  8. [Review of transgenic crop breeding in China].

    PubMed

    Huang, Dafang

    2015-06-01

    The development history and fundamental experience of transgenic crops (Genetically modified crops) breeding in China for near 30 years were reviewed. It was illustrated that a scientific research, development and industrialization system of transgenic crops including gene discovery, transformation, variety breeding, commercialization, application and biosafety assessment has been initially established which was few in number in the world. The research innovative capacity of transgenic cotton, rice and corn has been lifted. The research features as well as relative advantages have been initially formed. The problems and challenges of transgenic crop development were discussed. In addition, three suggestions of promoting commercialization, speeding up implementation of the Major National Project of GM Crops, and enhancing science communication were made. PMID:26672365

  9. Rapeseed species and environmental concerns related to loss of seeds of genetically modified oilseed rape in Japan.

    PubMed

    Nishizawa, Toru; Tamaoki, Masanori; Aono, Mitsuko; Kubo, Akihiro; Saji, Hikaru; Nakajima, Nobuyoshi

    2010-01-01

    Feral rapeseed in Japan consists of Brassica rapa, B. juncea and B. napus, mostly produced by escape from crops. Brassica rapa and B. juncea were introduced from abroad long ago as leaf and root vegetables and as an oil crop and breeders have developed various cultivars. Brassica napus was introduced in the late 1800s, mainly as an oil crop. Rapeseed production in Japan is low, and most demand is met by imports from Canada (94.4% of the 2009 trade volume). Recently, spontaneous B. napus, including genetically modified (GM) herbicide-resistant individuals, has been detected along Japanese roads, probably originating from seeds lost during transportation of imports. As GM oilseed production increases abroad, the probability of escape of GM oilseed rape in Japan will increase, raising environmental biosafety concerns related to the impact of feral rapeseed on heirloom brassicaceous crops. In this paper, we review the history of rapeseed introduction in Japan and future concerns. PMID:21844669

  10. Genome editing for crop improvement: Challenges and opportunities.

    PubMed

    Abdallah, Naglaa A; Prakash, Channapatna S; McHughen, Alan G

    2015-01-01

    Genome or gene editing includes several new techniques to help scientists precisely modify genome sequences. The techniques also enables us to alter the regulation of gene expression patterns in a pre-determined region and facilitates novel insights into the functional genomics of an organism. Emergence of genome editing has brought considerable excitement especially among agricultural scientists because of its simplicity, precision and power as it offers new opportunities to develop improved crop varieties with clear-cut addition of valuable traits or removal of undesirable traits. Research is underway to improve crop varieties with higher yields, strengthen stress tolerance, disease and pest resistance, decrease input costs, and increase nutritional value. Genome editing encompasses a wide variety of tools using either a site-specific recombinase (SSR) or a site-specific nuclease (SSN) system. Both systems require recognition of a known sequence. The SSN system generates single or double strand DNA breaks and activates endogenous DNA repair pathways. SSR technology, such as Cre/loxP and Flp/FRT mediated systems, are able to knockdown or knock-in genes in the genome of eukaryotes, depending on the orientation of the specific sites (loxP, FLP, etc.) flanking the target site. There are 4 main classes of SSN developed to cleave genomic sequences, mega-nucleases (homing endonuclease), zinc finger nucleases (ZFNs), transcriptional activator-like effector nucleases (TALENs), and the CRISPR/Cas nuclease system (clustered regularly interspaced short palindromic repeat/CRISPR-associated protein). The recombinase mediated genome engineering depends on recombinase (sub-) family and target-site and induces high frequencies of homologous recombination. Improving crops with gene editing provides a range of options: by altering only a few nucleotides from billions found in the genomes of living cells, altering the full allele or by inserting a new gene in a targeted region of

  11. Facile preparation of superamphiphobic epoxy resin/modified poly(vinylidene fluoride)/fluorinated ethylene propylene composite coating with corrosion/wear-resistance

    NASA Astrophysics Data System (ADS)

    Wang, Huaiyuan; Liu, Zhanjian; Wang, Enqun; Zhang, Xiguang; Yuan, Ruixia; Wu, Shiqi; Zhu, Yanji

    2015-12-01

    A robust superamphiphobic epoxy resin (EP)/modified poly(vinylidene fluoride) (MPVDF)/fluorinated ethylene propylene (FEP) composite coating has been prepared through the combination of chemical modification and spraying technique. Nanometer silica (SiO2, 2.5 wt.%) and carbon nanotubes (CNTs, 2.5 wt.%) were added in the coating to construct the necessary reticulate papillae structures for superamphiphobic surface. The prepared EP composite coating demonstrated high static contact angles (166°, 155°) and low sliding angles (3°, 5°) to water and glycerol, respectively. Moreover, the prepared coating can also retain superhydrophobicity under strongly acidic and alkaline conditions. The brittleness of EP can be avoided by introducing the malleable MPVDF. The wear life of the EP composite coating with 25 wt.% FEP was improved to 18 times of the pure EP coating. The increased wear life of the coating can be attributed to the designed nano/micro structures, the self-lubrication of FEP and the chemical reaction between EP and MPVDF. The anti-corrosion performance of the coatings was investigated in 3.5% NaCl solution using potentiodynamic polarization. The results showed that the prepared superamphiphobic composite coating was most effective in corrosion resistance, primarily due to the barrier effect for the diffusion of O2 and H2O molecules. It is believed that this robust superamphiphobic EP/MPVDF/FEP composite coating prepared by the facile spray method can pave a way for the large-scale application in pipeline transport.

  12. Intense Resistance Exercise Promotes the Acute and Transient Nuclear Translocation of Small Ubiquitin-Related Modifier (SUMO)-1 in Human Myofibres.

    PubMed

    Gehlert, Sebastian; Klinz, Franz Josef; Willkomm, Lena; Schiffer, Thorsten; Suhr, Frank; Bloch, Wilhelm

    2016-01-01

    Protein sumoylation is a posttranslational modification triggered by cellular stress. Because general information concerning the role of small ubiquitin-related modifier (SUMO) proteins in adult skeletal muscle is sparse, we investigated whether SUMO-1 proteins will be subjected to time-dependent changes in their subcellular localization in sarcoplasmic and nuclear compartments of human type I and II skeletal muscle fibers in response to acute stimulation by resistance exercise (RE). Skeletal muscle biopsies were taken at baseline (PRE), 15, 30, 60, 240 min and 24 h post RE from 6 male subjects subjected to a single bout of one-legged knee extensions. SUMO-1 localization was determined via immunohistochemistry and confocal laser microscopy. At baseline SUMO-1 was localized in perinuclear regions of myonuclei. Within 15 and up to 60 min post exercise, nuclear SUMO-1 localization was significantly increased (p < 0.01), declining towards baseline levels within 240 min post exercise. Sarcoplasmic SUMO-1 localization was increased at 15 min post exercise in type I and up to 30 min post RE in type II myofibres. The changing localization of SUMO-1 proteins acutely after intense muscle contractions points to a role for SUMO proteins in the acute regulation of the skeletal muscle proteome after exercise. PMID:27136539

  13. Chemical modification of metallic implant surfaces with biofunctional proteins (Part 2). Corrosion resistance of a chemically modified NiTi alloy.

    PubMed

    Endo, K

    1995-12-01

    The corrosion resistance of a NiTi alloy, chemically modified with a human plasma fibronectin (pFN) using an aminosilane and a glutaraldehyde, was examined by electrochemical techniques in a 0.9% NaCl solution and a cell culture medium containing serum. The role of serum proteins in influencing the passive behavior of the alloy was extensively studied by anodic polarization and X-ray photoelectron spectroscopy (XPS). The passive current density increased in the presence of serum proteins. The enhanced dissolution of the passive film appears to be a consequence of quick adsorption of the serum proteins and the subsequent formation of metal ion-protein complexes on the film surface. With the chemical modification, the corrosion rate was reduced by approximately 50% in both solutions due to a highly cross-linked siloxane network formed on the alloy surface. This network layer limited the diffusion of dissolved oxygen, metal ions, and biological molecules involved in the corrosion reactions. PMID:8940558

  14. A novel antimicrobial peptide derived from modified N-terminal domain of bovine lactoferrin: design, synthesis, activity against multidrug-resistant bacteria and Candida.

    PubMed

    Mishra, Biswajit; Leishangthem, Geeta Devi; Gill, Kamaldeep; Singh, Abhay K; Das, Swagata; Singh, Kusum; Xess, Immaculata; Dinda, Amit; Kapil, Arti; Patro, Ishan K; Dey, Sharmistha

    2013-02-01

    Lactoferrin (LF) is believed to contribute to the host's defense against microbial infections. This work focuses on the antibacterial and antifungal activities of a designed peptide, L10 (WFRKQLKW) by modifying the first eight N-terminal residues of bovine LF by selective homologous substitution of amino acids on the basis of hydrophobicity, L10 has shown potent antibacterial and antifungal properties against clinically isolated extended spectrum beta lactamases (ESBL), producing gram-negative bacteria as well as Candida strains with minimal inhibitory concentrations (MIC) ranging from 1 to 8 μg/mL and 6.5 μg/mL, respectively. The peptide was found to be least hemolytic at a concentration of 800 μg/mL. Interaction with lipopolysaccharide (LPS) and lipid A (LA) suggests that the peptide targets the membrane of gram-negative bacteria. The membrane interactive nature of the peptide, both antibacterial and antifungal, was further confirmed by visual observations employing electron microscopy. Further analyses, by means of propidium iodide based flow cytometry, also supported the membrane permeabilization of Candida cells. The peptide was also found to possess anti-inflammatory properties, by virtue of its ability to inhibit cyclooxygenase-2 (COX-2). L10 therefore emerges as a potential therapeutic remedial solution for infections caused by ESBL positive, gram-negative bacteria and multidrug-resistant (MDR) fungal strains, on account of its multifunctional activities. This study may open up new approach to develop and design novel antimicrobials. PMID:23026014

  15. Intense Resistance Exercise Promotes the Acute and Transient Nuclear Translocation of Small Ubiquitin-Related Modifier (SUMO)-1 in Human Myofibres

    PubMed Central

    Gehlert, Sebastian; Klinz, Franz Josef; Willkomm, Lena; Schiffer, Thorsten; Suhr, Frank; Bloch, Wilhelm

    2016-01-01

    Protein sumoylation is a posttranslational modification triggered by cellular stress. Because general information concerning the role of small ubiquitin-related modifier (SUMO) proteins in adult skeletal muscle is sparse, we investigated whether SUMO-1 proteins will be subjected to time-dependent changes in their subcellular localization in sarcoplasmic and nuclear compartments of human type I and II skeletal muscle fibers in response to acute stimulation by resistance exercise (RE). Skeletal muscle biopsies were taken at baseline (PRE), 15, 30, 60, 240 min and 24 h post RE from 6 male subjects subjected to a single bout of one-legged knee extensions. SUMO-1 localization was determined via immunohistochemistry and confocal laser microscopy. At baseline SUMO-1 was localized in perinuclear regions of myonuclei. Within 15 and up to 60 min post exercise, nuclear SUMO-1 localization was significantly increased (p < 0.01), declining towards baseline levels within 240 min post exercise. Sarcoplasmic SUMO-1 localization was increased at 15 min post exercise in type I and up to 30 min post RE in type II myofibres. The changing localization of SUMO-1 proteins acutely after intense muscle contractions points to a role for SUMO proteins in the acute regulation of the skeletal muscle proteome after exercise. PMID:27136539

  16. Corrosion resistance of siloxane-poly(methyl methacrylate) hybrid films modified with acetic acid on tin plate substrates: Influence of tetraethoxysilane addition

    NASA Astrophysics Data System (ADS)

    Kunst, S. R.; Cardoso, H. R. P.; Oliveira, C. T.; Santana, J. A.; Sarmento, V. H. V.; Muller, I. L.; Malfatti, C. F.

    2014-04-01

    The aim of this paper is to study the corrosion resistance of hybrid films. Tin plate was coated with a siloxane-poly (methyl methacrylate) (PMMA) hybrid film prepared by sol-gel route with covalent bonds between the organic (PMMA) and inorganic (siloxane) phases obtained by hydrolysis and polycondensation of 3-(trimethoxysilylpropyl) methacrylate (TMSM) and polymerization of methyl methacrylate (MMA) using benzoyl peroxide (BPO) as a thermic initiator. Hydrolysis reactions were catalyzed by acetic acid solution avoiding the use of chlorine or stronger acids in the film preparation. The effect of the addition of tetraethoxysilane (TEOS) on the protective properties of the film was evaluated. The hydrophobicity of the film was determined by contact angle measurements, and the morphology was evaluated by scanning electron microscopy (SEM) and profilometry. The local nanostructure was investigated by Fourier transform infrared spectroscopy (FT-IR). The electrochemical behavior of the films was assessed by open circuit potential monitoring, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements in a 0.05 M NaCl solution. The mechanical behavior was evaluated by tribology. The results highlighted that the siloxane-PMMA hybrid films modified with acetic acid are promising anti-corrosive coatings that acts as an efficient diffusion barrier, protecting tin plates against corrosion. However, the coating properties were affected by the TEOS addition, which contributed for the thickness increase and irregular surface coverage.

  17. Evaluation of Oxidative Stress in Women with Polycystic Ovarian Syndrome as Represented by Serum Ischemia Modified Albumin and Its Correlation with Testosterone and Insulin Resistance.

    PubMed

    Beyazit, Fatma; Yilmaz, Nafiye; Balci, Osman; Adam, Magdi; Yaman, Selen Taflan

    2016-01-01

    Objective Ischemia-mediated oxidative stress and inflammation have been reported to be important contributors to the pathogenesis of polycystic ovary syndrome (PCOS). Ischemia-modified albumin (IMA) is a novel marker generated under ischemic and oxidative conditions and may reflect disease activity in distinct disease states. Therefore, we investigated whether the serum IMA levels are affected in infertile PCOS patients. Methods Forty-six patients with infertile PCOS, 30 patients with unexplained infertility, and 31 age- and body mass index (BMI)-matched controls were included in this cross-sectional study. Biochemical parameters, serum IMA levels, and their correlations with serum testosterone and insulin resistance were determined for each subject. Results In patients with infertile PCOS, the serum IMA levels were significantly elevated (p=0.003) compared with unexplained infertility patients and controls. A correlation analysis suggested that the IMA levels only correlated with the serum free testosterone levels in PCOS patients (r=0.43, p=0.028). Conclusion Elevations in the serum IMA levels in infertile PCOS patients may suggest a possible additional role of oxidative stress mechanisms in disease pathophysiology. Moreover, correlation between serum IMA and testosterone levels may influence the quality of oocytes via alterations in the balance of critical follicular fluid factors in the follicular microenvironment. PMID:27580534

  18. GM as a route for delivery of sustainable crop protection.

    PubMed

    Bruce, Toby J A

    2012-01-01

    Modern agriculture, with its vast monocultures of lush fertilized crops, provides an ideal environment for adapted pests, weeds, and diseases. This vulnerability has implications for food security: when new pesticide-resistant pest biotypes evolve they can devastate crops. Even with existing crop protection measures, approximately one-third yield losses occur globally. Given the projected increase in demand for food (70% by 2050 according to the UN), sustainable ways of preventing these losses are needed. Development of resistant crop cultivars can make an important contribution. However, traditional crop breeding programmes are limited by the time taken to move resistance traits into elite crop genetic backgrounds and the limited gene pools in which to search for novel resistance. Furthermore, resistance based on single genes does not protect against the full spectrum of pests, weeds, and diseases, and is more likely to break down as pests evolve counter-resistance. Although not necessarily a panacea, GM (genetic modification) techniques greatly facilitate transfer of genes and thus provide a route to overcome these constraints. Effective resistance traits can be precisely and conveniently moved into mainstream crop cultivars. Resistance genes can be stacked to make it harder for pests to evolve counter-resistance and to provide multiple resistances to different attackers. GM-based crop protection could substantially reduce the need for farmers to apply pesticides to their crops and would make agricultural production more efficient in terms of resources used (land, energy, water). These benefits merit consideration by environmentalists willing to keep an open mind on the GM debate. PMID:22016426

  19. AIRBORNE REMOTELY SENSED INFORMATION FOR PESTICIDAL TRANSGENIC CROPS: HOW SPECTRAL IMAGING MAY PLAY A ROLE

    EPA Science Inventory

    The importance of sustainability to Bt crops. Resistance management as a sustainability strategy. The importance of data quality to sustainability and regulation of Bt Crops. Where information improvement can be useful across the globe.

  20. Dealing with transgene flow of crop protection traits from crops to their relatives.

    PubMed

    Gressel, Jonathan

    2015-05-01

    Genes regularly move within species, to/from crops, as well as to their con- specific progenitors, feral and weedy forms ('vertical' gene flow). Genes occasionally move to/from crops and their distantly related, hardly sexually interbreeding relatives, within a genus or among closely related genera (diagonal gene flow). Regulators have singled out transgene flow as an issue, yet non-transgenic herbicide resistance traits pose equal problems, which cannot be mitigated. The risks are quite different from genes flowing to natural (wild) ecosystems versus ruderal and agroecosystems. Transgenic herbicide resistance poses a major risk if introgressed into weedy relatives; disease and insect resistance less so. Technologies have been proposed to contain genes within crops (chloroplast transformation, male sterility) that imperfectly prevent gene flow by pollen to the wild. Containment does not prevent related weeds from pollinating crops. Repeated backcrossing with weeds as pollen parents results in gene establishment in the weeds. Transgenic mitigation relies on coupling crop protection traits in a tandem construct with traits that lower the fitness of the related weeds. Mitigation traits can be morphological (dwarfing, no seed shatter) or chemical (sensitivity to a chemical used later in a rotation). Tandem mitigation traits are genetically linked and will move together. Mitigation traits can also be spread by inserting them in multicopy transposons which disperse faster than the crop protection genes in related weeds. Thus, there are gene flow risks mainly to weeds from some crop protection traits; risks that can and should be dealt with. PMID:24977384

  1. Effect of High- versus Low-Intensity Supervised Aerobic and Resistance Training on Modifiable Cardiovascular Risk Factors in Type 2 Diabetes; The Italian Diabetes and Exercise Study (IDES)

    PubMed Central

    Cardelli, Patrizia; Salvi, Laura; Bazuro, Alessandra; Pugliese, Luca; Maccora, Carla; Iacobini, Carla; Conti, Francesco G.; Nicolucci, Antonio; Pugliese, Giuseppe

    2012-01-01

    Background While current recommendations on exercise type and volume have strong experimental bases, there is no clear evidence from large-sized studies indicating whether increasing training intensity provides additional benefits to subjects with type 2 diabetes. Objective To compare the effects of moderate-to-high intensity (HI) versus low-to-moderate intensity (LI) training of equal energy cost, i.e. exercise volume, on modifiable cardiovascular risk factors. Design Pre-specified sub-analysis of the Italian Diabetes and Exercise Study (IDES), a randomized multicenter prospective trial comparing a supervised exercise intervention with standard care for 12 months (2005–2006). Setting Twenty-two outpatient diabetes clinics across Italy. Patients Sedentary patients with type 2 diabetes assigned to twice-a-week supervised progressive aerobic and resistance training plus exercise counseling (n = 303). Interventions Subjects were randomized by center to LI (n = 142, 136 completed) or HI (n = 161, 152 completed) progressive aerobic and resistance training, i.e. at 55% or 70% of predicted maximal oxygen consumption and at 60% or 80% of predicted 1-Repetition Maximum, respectively, of equal volume. Main Outcome Measure(s) Hemoglobin (Hb) A1c and other cardiovascular risk factors; 10-year coronary heart disease (CHD) risk scores. Results Volume of physical activity, both supervised and non-supervised, was similar in LI and HI participants. Compared with LI training, HI training produced only clinically marginal, though statistically significant, improvements in HbA1c (mean difference −0.17% [95% confidence interval −0.44,0.10], P = 0.03), triglycerides (−0.12 mmol/l [−0.34,0.10], P = 0.02) and total cholesterol (−0.24 mmol/l [−0.46, −0.01], P = 0.04), but not in other risk factors and CHD risk scores. However, intensity was not an independent predictor of reduction of any of these parameters. Adverse event rate was similar in HI and

  2. Crop synergism can help dryland crop production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water supply is a major constraint for crop production in dryland agriculture across the world, and extensive research has been conducted to improve water use. In the grass steppe of the United States, water use has improved through a series of management advancements, such as preservation of crop ...

  3. Airflow resistance in soybean

    NASA Astrophysics Data System (ADS)

    Kenghe, R. N.; Nimkar, P. M.; Shirkole, S. S.; Shinde, K. J.

    2012-04-01

    Resistance of material to airflow is an important factor to consider in the design of a dryer or an aeration system. The airflow resistance of soybean was determined with the modified airflow resistance apparatus. It was found that pressure drop increased with increase in airflow rate, bulk density, bed depth and decreased with moisture content. Modified Shedd equation, Hukill and Ives equation and modified Ergun equation were examined for pressure drop prediction. Airflow resistance was accurately described by modified Shedd equation followed by Hukill and Ives equation and modified Ergun equation. The developed statistical model comprised of airflow rate, moisture content and bulk density could fit pressure drop data reasonably well.

  4. New indicators for global crop monitoring in CropWatch -case study in North China Plain

    NASA Astrophysics Data System (ADS)

    Bingfang, Wu; Miao, Zhang; Hongwei, Zeng; Guoshui, Liu; Sheng, Chang; Gommes, René

    2014-03-01

    CropWatch is a monitoring system developed and operated by the Institute of Remote Sensing and Digital Earth (Chinese Academy of Sciences) to provide global-scale crop information. Now in its 15th year of operation, CropWatch was modified several times to be a timely, comprehensive and independent global agricultural monitoring system using advanced remote sensing technology. Currently CropWatch is being upgraded with new indicators based on new sensors, especially those on board of China Environmental Satellite (HJ-1 CCD), the Medium Resolution Spectral Imager (MERSI) on Chinese meteorological satellite (FY-3A) and cloud classification products of FY-2. With new satellite data, CropWatch will generate new indicators such as fallow land ratio (FLR), crop condition for irrigated (CCI) and non-irrigated (CCNI) areas separately, photosynthetically active radiation (PAR), radiation use efficiency for the photosynthetically active radiation (RUEPAR) and cropping index (CI) with crop rotation information (CRI). In this paper, the methods for monitoring the new indicators are applied to the North China Plain which is one of the major grain producing areas in China. This paper shows the preliminary results of the new indicators and methods; they still need to be thoroughly validated before being incorporated into the operational CropWatch system. In the future, the new and improved indicators will help us to better understand the global situation of food security.

  5. USEPA Resistance Management Model development

    EPA Science Inventory

    The US EPA requires registrants of plant incorporated protectant (PIP) crops to provide information relating to the time frame for pest resistance development related to the control traits of the crop. Simulation models are used to evaluate the future conditions for resistance de...

  6. Association between PPAR-γ2 Pro12Ala genotype and insulin resistance is modified by circulating lipids in Mexican children

    PubMed Central

    Stryjecki, Carolina; Peralta-Romero, Jesus; Alyass, Akram; Karam-Araujo, Roberto; Suarez, Fernando; Gomez-Zamudio, Jaime; Burguete-Garcia, Ana; Cruz, Miguel; Meyre, David

    2016-01-01

    The Pro12Ala (rs1801282) polymorphism in peroxisome proliferator-activated receptor-γ2 (PPAR-γ2) has been convincingly associated with insulin resistance (IR) and type 2 diabetes (T2D) among Europeans, in interaction with a high-fat diet. Mexico is disproportionally affected by obesity and T2D however, whether the Pro12Ala polymorphism is associated with early metabolic complications in this population is unknown. We assessed the association of PPAR-γ2 Pro12Ala with metabolic traits in 1457 Mexican children using linear regression models. Interactions between PPAR-γ2 Pro12Ala and circulating lipids on metabolic traits were determined by adding an interaction term to regression models. We observed a high prevalence of overweight/obesity (49.2%), dyslipidemia (34.9%) and IR (11.1%). We detected nominally significant/significant interactions between lipids (total cholesterol, HDL-cholesterol, LDL-cholesterol), the PPAR-γ2 Pro12Ala genotype and waist-to-hip ratio, fasting insulin, HOMA-IR and IR (9.30 × 10−4  ≤ Pinteraction ≤ 0.04). Post-hoc subgroup analyses evidenced that the association between the PPAR-γ2 Pro12Ala genotype and fasting insulin, HOMA-IR and IR was restricted to children with total cholesterol or LDL-cholesterol values higher than the median (0.02 ≤ P ≤ 0.03). Our data support an association of the Pro12Ala polymorphism with IR in Mexican children and suggest that this relationship is modified by dyslipidemia. PMID:27075119

  7. Factors influencing the transfection efficiency and cellular uptake mechanisms of Pluronic P123-modified polypropyleneimine/pDNA polyplexes in multidrug resistant breast cancer cells.

    PubMed

    Gu, Jijin; Hao, Junguo; Fang, Xiaoling; Sha, Xianyi

    2016-04-01

    Generally, the major obstacles for efficient gene delivery are cellular internalization and endosomal escape of nucleic acid such as plasmid DNA (pDNA) or small interfering RNA (siRNA). We previously developed Pluronic P123 modified polypropyleneimine (PPI)/pDNA (P123-PPI/pDNA) polyplexes as a gene delivery system. The results showed that P123-PPI/pDNA polyplexes revealed higher transfection efficiency than PPI/pDNA polyplexes in multidrug resistant breast cancer cells. As a continued effort, the present investigation on the factors influencing the transfection efficiency, cellular uptake mechanisms, and intracellular fate of P123-PPI/pDNA polyplexes is reported. The presence of P123 was the main factor influencing the transfection efficiency of P123-PPI/pDNA polyplexes in MCF-7/ADR cells, but other parameters, such as N/P ratio, FBS concentration, incubation time and temperature were important as well. The endocytic inhibitors against clathrin-mediated endocytosis (CME), caveolae-mediated endocytosis (CvME), and macropinocytosis were involved in the internalization to investigate their effects on the cellular uptake and transfection efficiency of P123-PPI/pDNA polyplexes in vitro. The data showed that the internalization of P123-PPI/pDNA polyplexes was obtained from both CME and CvME. Colocalization experiments with TRITC-transferrin (CME indicator), Alexa Fluor 555-CTB (CvME indicator), monoclonal anti-α-tubulin (microtubule indicator), and LysoTracker Green (Endosome/lysosome indicator) were carried out to confirm the internalization routes. The results showed that both CME and CvME played vital roles in the effective transfection of P123-PPI/pDNA polyplexes. Endosome/lysosome system and skeleton, including actin filament and microtubule, were necessary for the transportation after internalization. PMID:26741268

  8. Loss of NPC1 function in a patient with a co-inherited novel insulin receptor mutation does not grossly modify the severity of the associated insulin resistance.

    PubMed

    Kirk, J; Porter, K M; Parker, V; Barroso, I; O'Rahilly, S; Hendriksz, C; Semple, R K

    2010-12-01

    In Npc1 null mice, a model for Niemann Pick Disease Type C1, it has been reported that hepatocyte insulin receptor function is significantly impaired, consistent with growing evidence that membrane fluidity and microdomain structure have an important role in insulin signal transduction. However, whether insulin receptor function is also compromised in human Niemann Pick disease Type C1 is unclear. We now report a girl who developed progressive dementia, ataxia and opthalmoplegia from 9 years old, followed by severe acanthosis nigricans, hirsutism and acne at 11 years old. She was diagnosed with Niemann Pick Disease type C1 (OMIM#257220) based on positive filipin staining and reduced cholesterol-esterifying activity in dermal fibroblasts, and homozygosity for the p.Ile1061Thr NPC1 mutation. Further analysis revealed her also to be heterozygous for a novel trinucleotide deletion (c.3659 + 1_3659 + 3delGTG) at the end of exon 20 of INSR, encoding the insulin receptor, leading to deletion of Trp1193 in the intracellular tyrosine kinase domain. INSR mRNA and protein levels were normal in dermal fibroblasts, consistent with a primary signal transduction defect in the mutant receptor. Although the proband was significantly more insulin resistant than her father, who carried the INSR mutation but was only heterozygous for the NPC1 variant, their respective degrees of IR were very similar to those previously reported in a father-daughter pair with the closely related p.Trp1193Leu INSR mutation. This suggests that loss of NPC1 function, with attendant changes in membrane cholesterol composition, does not significantly modify the IR phenotype, even in the context of severely impaired INSR function. PMID:20521171

  9. Wind Turbines Benefit Crops

    SciTech Connect

    Takle, Gene

    2010-01-01

    Ames Laboratory associate scientist Gene Takle talks about research into the effect of wind turbines on nearby crops. Preliminary results show the turbines may have a positive effect by cooling and drying the crops and assisting with carbon dioxide uptake.

  10. Wind Turbines Benefit Crops

    ScienceCinema

    Takle, Gene

    2013-03-01

    Ames Laboratory associate scientist Gene Takle talks about research into the effect of wind turbines on nearby crops. Preliminary results show the turbines may have a positive effect by cooling and drying the crops and assisting with carbon dioxide uptake.

  11. Transgenic Crops: Implications for Biodiversity and Sustainable Agriculture

    ERIC Educational Resources Information Center

    Garcia, Maria Alice; Altieri, Miguel A.

    2005-01-01

    The potential for genetically modified (GM) crops to threaten biodiversity conservation and sustainable agriculture is substantial. Megadiverse countries and centers of origin and/or diversity of crop species are particularly vulnerable regions. The future of sustainable agriculture may be irreversibly jeopardized by contamination of in situ…

  12. Sorghums as energy crops

    SciTech Connect

    Lipinsky, E. S.; Kresovich, S.

    1980-01-01

    The botanical, physiological, and agronomic characteristics of sorghum are described. Integration concepts to improve sorghum prospects are discussed as follows: multiple sweet sorghum crops each year, integration with sugarcane, integration with sugar beets, integration with starch crops, sweet stemmed grain sorghum, and integration with lignocellulosic crops. (MHR)

  13. Cucurbitaceae (Vine Crops)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Cucurbitaceae or vine crop family is a distinct family without any close relatives. The Cucurbitaceae or vine crop family includes many important vegetables collectively referred to as cucurbits. Cucumber, melon, and watermelon are major crop species originally from the Old World (cucumber fro...

  14. Cover crops for Alabama

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops are grown to benefit the following crop as well as to improve the soil, but they are normally not intended for harvest. Selecting the right cover crops for farming operations can improve yields, soil and water conservation and quality, and economic productivity. Properly managed cover ...

  15. Cover Crop Management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potential benefits of cover crops in vegetable production systems depend on the type of cover crop that is used and how it is managed from planting to termination date. This chapter focuses on management practices that are applicable to a broad range cover crops and vegetable production systems ...

  16. Functional molecular markers for crop improvement.

    PubMed

    Kage, Udaykumar; Kumar, Arun; Dhokane, Dhananjay; Karre, Shailesh; Kushalappa, Ajjamada C

    2016-10-01

    A tremendous decline in cultivable land and resources and a huge increase in food demand calls for immediate attention to crop improvement. Though molecular plant breeding serves as a viable solution and is considered as "foundation for twenty-first century crop improvement", a major stumbling block for crop improvement is the availability of a limited functional gene pool for cereal crops. Advancement in the next generation sequencing (NGS) technologies integrated with tools like metabolomics, proteomics and association mapping studies have facilitated the identification of candidate genes, their allelic variants and opened new avenues to accelerate crop improvement through development and use of functional molecular markers (FMMs). The FMMs are developed from the sequence polymorphisms present within functional gene(s) which are associated with phenotypic trait variations. Since FMMs obviate the problems associated with random DNA markers, these are considered as "the holy grail" of plant breeders who employ targeted marker assisted selections (MAS) for crop improvement. This review article attempts to consider the current resources and novel methods such as metabolomics, proteomics and association studies for the identification of candidate genes and their validation through virus-induced gene silencing (VIGS) for the development of FMMs. A number of examples where the FMMs have been developed and used for the improvement of cereal crops for agronomic, food quality, disease resistance and abiotic stress tolerance traits have been considered. PMID:26171816

  17. [Genetically modified foods. Advantages and human health risks].

    PubMed

    Filip, Lorena; Miere, Doina; Indrei, L L

    2004-01-01

    One of the most important issue with which the mankind is confronting now is related to the quantitatively as well as qualitatively assurance of the food supply necessary for human species existence. In this context, by means of genetic engineering, modified genetic organisms were obtained. In the first stage, plant crops with high productivity and resistant against diseases and pests were obtained. After that, food products having modified organoleptic properties and high nutrition values were produced. The main problem concerning the long-term consumption of these products is their toxicity, which until now was not confirmed or denied. For this reason, tests are necessary to be made in order to stipulate and prevent these effects. PMID:16004228

  18. Bt Crops and Invertebrate Non-target Effects – Revisited

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crops that have been transgenically engineered for resistance to select insect pests by the use of genes from a common soil bacteria (Bacillus thuringiensis) were grown on about 42 million hectares in 20 countries in 2007. Debate continues on the environmental risk of these crops. This short artic...

  19. Enhancing crop innate immunity: new promising trends

    PubMed Central

    Huang, Pin-Yao; Zimmerli, Laurent

    2014-01-01

    Plants are constantly exposed to potentially pathogenic microbes present in their surrounding environment. Due to the activation of the pattern-triggered immunity (PTI) response that largely relies on accurate detection of pathogen- or microbe-associated molecular patterns by pattern-recognition receptors (PRRs), plants are resistant to the majority of potential pathogens. However, adapted pathogens may avoid recognition or repress plant PTI and resulting diseases significantly affect crop yield worldwide. PTI provides protection against a wide range of pathogens. Reinforcement of PTI through genetic engineering may thus generate crops with broad-spectrum field resistance. In this review, new approaches based on fundamental discoveries in PTI to improve crop immunity are discussed. Notably, we highlight recent studies describing the interfamily transfer of PRRs or key regulators of PTI signaling. PMID:25414721

  20. Coping Mechanisms for Crop Plants in Drought-prone Environments

    PubMed Central

    Neumann, Peter M.

    2008-01-01

    Background Drought is a major limitation to plant productivity. Various options are available for increasing water availability and sustaining growth of crop plants in drought-prone environments. Scope After a general introduction to the problems of water availability, this review focuses on a critical evaluation of recent progress in unravelling mechanisms for modifying plant growth responses to drought. Conclusions Investigations of key regulatory mechanisms integrating plant growth responses to water deficits at the whole-organism, cellular and genomic levels continue to provide novel and exiting research findings. For example, recent reports contradict the widespread conception that root-derived abscisic acid is necessarily involved in signalling for stomatal and shoot-growth responses to soil water deficits. The findings bring into question the theoretical basis for alternate-side root-irrigation techniques. Similarly, recent reports indicate that increased ABA production or increased aquaporin expression did not lead to improved drought resistance. Other reports have concerned key genes and proteins involved in regulation of flowering (FT), vegetative growth (DELLA), leaf senescence (IPT) and desiccation tolerance (LEA). Introgression of such genes, with suitable promoters, can greatly impact on whole-plant responses to drought. Further developments could facilitate the introduction by breeders of new crop varieties with growth physiologies tailored to improved field performance under drought. Parallel efforts to encourage the introduction of supplementary irrigation with water made available by improved conservation measures and by sea- or brackish-water desalination, will probably provide comprehensive solutions to coping with drought-prone environments. PMID:18252764

  1. Impact of Transgene Inheritance on the Mitigation of Gene Flow Between Crops and Their Wild Relatives: The Example of Foxtail Millet

    PubMed Central

    Shi, Yunsu; Wang, TianYu; Li, Yu; Darmency, Henri

    2008-01-01

    Developing genetically modified crop plants that are biologically contained could reduce significantly the potential spread of transgenes to conventional and organic crop plants and to wild or weedy relatives. Among several strategies, the hereditary mode of transmission of transgenes, whether dominant, recessive, or maternal, could play a major role in interspecific gene flow. Here we report on the gene flow between foxtail millet (Setaria italica), an autogamous crop, and its weedy relative, S. viridis, growing within or beside fields containing the three kinds of inherited herbicide resistance. Over the 6-year study, in the absence of herbicide selection, the maternal chloroplast-inherited resistance was observed at a 2 × 10−6 frequency in the weed populations. Resistant weed plants were observed 60 times as often, at 1.2 × 10−4 in the case of the nuclear recessive resistance, and 190 times as often, at 3.9 × 10−4 in the case of the dominant resistance. Because the recessive gene was not expressed in the first-generation hybrids, it should be more effective than dominant genes in reducing gene flow under normal agricultural conditions where herbicides are sprayed because interspecific hybrids cannot gain from beneficial genes. PMID:18780732

  2. Can genomics boost productivity of orphan crops?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Advances in genomics over the past 20 years have enhanced the precision and efficiency of breeding programs in many temperate cereal crops. One of the first applications of genomics-assisted breeding has been the introgression of loci for resistance to biotic stresses or major quantitative trait loc...

  3. Consumer perception of genetically modified organisms and sources of information.

    PubMed

    Wunderlich, Shahla; Gatto, Kelsey A

    2015-11-01

    Genetically modified organisms (GMOs) have been available for commercial purchase since the 1990s, allowing producers to increase crop yields through bioengineering that creates herbicide-resistant and insect-resistant varieties. However, consumer knowledge about GMOs has not increased at the same rate as the adoption of GMO crops. Consumers worldwide are displaying limited understanding, misconceptions, and even unfamiliarity with GMO food products. Many consumers report that they receive information about GMO food products from the media, Internet, and other news sources. These sources may be less reliable than scientific experts whom consumers trust more to present the facts. Although many in the United States support mandatory GMO labeling (similar to current European standards), consumer awareness of current GMO labeling is low. A distinction must also be made between GMO familiarity and scientific understanding, because those who are more familiar with it tend to be more resistant to bioengineering, whereas those with higher scientific knowledge scores tend to have less negative attitudes toward GMOs. This brings to question the relation between scientific literacy, sources of information, and overall consumer knowledge and perception of GMO foods. PMID:26567205

  4. Attitudes of European farmers towards GM crop adoption.

    PubMed

    Areal, Francisco J; Riesgo, Laura; Rodríguez-Cerezo, Emilio

    2011-12-01

    This article analyses European Union (EU) farmers' attitudes towards adoption of genetically modified crops by identifying and classifying groups of farmers. Cluster analysis provided two groups of farmers allowing us to classify farmers into potential adopters or rejecters of genetically modified herbicide-tolerant (GMHT) crops. Results showed that economic issues such as the guarantee of a higher income and the reduction of weed control costs are the most encouraging reasons for potential adopters and rejecters of GMHT crops. This article also examines how putting in place measures to ensure coexistence between GM and non-GM crops may influence farmers' attitudes towards GMHT crop adoption. Results show that the implementation of a coexistence policy would have a negative impact on farmers' attitudes on adoption and consequently may hamper GMHT adoption in the EU. PMID:21923717

  5. Aminoglycoside Modifying Enzymes

    PubMed Central

    Ramirez, Maria S.; Tolmasky, Marcelo E.

    2010-01-01

    Aminoglycosides have been an essential component of the armamentarium in the treatment of life-threatening infections. Unfortunately, their efficacy has been reduced by the surge and dissemination of resistance. In some cases the levels of resistance reached the point that rendered them virtually useless. Among many known mechanisms of resistance to aminoglycosides, enzymatic modification is the most prevalent in the clinical setting. Aminoglycoside modifying enzymes catalyze the modification at different −OH or −NH2 groups of the 2-deoxystreptamine nucleus or the sugar moieties and can be nucleotidyltranferases, phosphotransferases, or acetyltransferases. The number of aminoglycoside modifying enzymes identified to date as well as the genetic environments where the coding genes are located is impressive and there is virtually no bacteria that is unable to support enzymatic resistance to aminoglycosides. Aside from the development of new aminoglycosides refractory to as many as possible modifying enzymes there are currently two main strategies being pursued to overcome the action of aminoglycoside modifying enzymes. Their successful development would extend the useful life of existing antibiotics that have proven effective in the treatment of infections. These strategies consist of the development of inhibitors of the enzymatic action or of the expression of the modifying enzymes. PMID:20833577

  6. Economic Analysis of Energy Crop Production in the U.S. - Location, Quantities, Price, and Impacts on Traditional Agricultural Crops

    SciTech Connect

    Walsh, M.E.; De La Torre Ugarte, D.; Slinsky, S.; Graham, R.L.; Shapouri, H.; Ray, D.

    1998-10-04

    POLYSYS is used to estimate US locations where, for any given energy crop price, energy crop production can be economically competitive with conventional crops. POLYSYS is a multi-crop, multi-sector agricultural model developed and maintained by the University of Tennessee and used by the USDA-Economic Research Service. It includes 305 agricultural statistical districts (ASD) which can be aggregated to provide state, regional, and national information. POLYSYS is being modified to include switchgrass, hybrid poplar, and willow on all land suitable for their production. This paper summarizes the preliminary national level results of the POLYSYS analysis for selected energy crop prices for the year 2007 and presents the corresponding maps (for the same prices) of energy crop production locations by ASD. Summarized results include: (1) estimates of energy crop hectares (acres) and quantities (dry Mg, dry tons), (2) identification of traditional crops allocated to energy crop production and calculation of changes in their prices and hectares (acres) of production, and (3) changes in total net farm returns for traditional agricultural crops. The information is useful for identifying areas of the US where large quantities of lowest cost energy crops can most likely be produced.

  7. Allelopathic cover crop prior to seeding is more important than subsequent grazing/mowing in grassland establishment

    USGS Publications Warehouse

    Milchunas, Daniel G.; Vandever, Mark W.; Ball, Leonard O.; Hyberg, Skip

    2011-01-01

    The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat–fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area

  8. Allelopathic cover crop prior to seeding is more important than subsequent grazing/mowing in Grassland establishment

    USGS Publications Warehouse

    Milchunas, D.G.; Vandever, M.W.; Ball, L.O.; Hyberg, S.

    2011-01-01

    The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat-fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area of

  9. A light-modified ferroelectric resistive switching behavior in Ag/BaMoO{sub 4}/FTO device at ambient temperature

    SciTech Connect

    Zhao, W.X.; Sun, B.; Liu, Y.H.; Wei, L.J.; Li, H.W.; Chen, P.

    2014-12-15

    BaMoO{sub 4} powder was prepared by a facile hydrothermal synthesis. And the BaMoO{sub 4}/FTO device was fabricated by a spin-coated method, in which the thickness of BaMoO{sub 4} layer is about 20 µm. The bipolar resistive switching effect has been observed in Ag/BaMoO{sub 4}/FTO device. Moreover, the resistive switching effect of the device is greatly improved by white light irradiation. The resistive switching behavior is explained by the polarization reversal that changes the charge distribution and modulates the Schottky barriers. - Graphical abstract: We fabricate a resistive switching device based on Ag/BaMoO{sub 4}/FTO, the device shows superior white-light controlled bipolar resistive switching memristive characteristics. - Highlights: • The BaMoO{sub 4} nanosquares powder was prepared by a hydrothermal synthesis. • The resistive switching of the Ag/BaMoO{sub 4}/FTO device was observed for the first time. • It is shown that the resistive switching is greatly improved under the white light irradiation. • The mechanism of resistive switching is attributed to the ferroelectric polarization reversal.

  10. Determination of crop coefficients (Kc) for irrigation management of crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weighing lysimeters are used to measure crop water use during the growing season. By relating the water use of a specific crop to a well-watered reference crop such as grass, crop coefficients (Kc) can be developed to assist in predicting crop needs using meteorological data available from weather ...

  11. Advancing environmental risk assessment for transgenic biofeedstock crops

    PubMed Central

    Wolt, Jeffrey D

    2009-01-01

    Transgenic modification of plants is a key enabling technology for developing sustainable biofeedstocks for biofuels production. Regulatory decisions and the wider acceptance and development of transgenic biofeedstock crops are considered from the context of science-based risk assessment. The risk assessment paradigm for transgenic biofeedstock crops is fundamentally no different from that of current generation transgenic crops, except that the focus of the assessment must consider the unique attributes of a given biofeedstock crop and its environmental release. For currently envisioned biofeedstock crops, particular emphasis in risk assessment will be given to characterization of altered metabolic profiles and their implications relative to non-target environmental effects and food safety; weediness and invasiveness when plants are modified for abiotic stress tolerance or are domesticated; and aggregate risk when plants are platforms for multi-product production. Robust risk assessments for transgenic biofeedstock crops are case-specific, initiated through problem formulation, and use tiered approaches for risk characterization. PMID:19883509

  12. MATERNAL EFFECTS IN ADVANCED HYBRIDS OF GENETICALLY MODIFIED AND NON-GENETICALLY MODIFIED BRASSICA SPECIES

    EPA Science Inventory

    Identification of fitness traits potentially impacted by gene flow from genetically modified (GM) crops to compatible relatives is of interest in risk assessments for GM crops. Reciprocal crosses were made between GM canola, Brassica napus cv. RaideRR that expresses CP4 EPSPS fo...

  13. Early detection of crop injury from herbicide glyphosate by leaf biochemical parameter inversion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early detection of crop injury from glyphosate is of significant importance in crop management. In this paper, we attempt to detect glyphosate-induced crop injury by PROSPECT (leaf optical PROperty SPECTra model) inversion through leaf hyperspectral reflectance measurements for non-Glyphosate-Resist...

  14. [Mechanism on biodiversity managing crop diseases].

    PubMed

    Yang, Jing; Shi, Zhu-Feng; Gao, Dong; Liu, Lin; Zhu, You-Yong; Li, Cheng-Yun

    2012-11-01

    Reasonable utilization of natural resource and protection of ecological environment is the foundation for implementing agricultural sustainable development. Biodiversity research and protection are becoming an important issue concerned commonly in the world. Crop disease is one of the important natural disasters for food production and safety, and is also one of the main reasons that confine sustainable development of agricultural production. Large-scale deployment of single highly resistant variety results in reduction of agro-biodiversity level. In this case, excessive loss of agro-biodiversity has become the main challenge in sustainable agriculture. Biodiversity can not only effectively alleviate disease incidence and loss of crop production, but also reduce pollution of agricultural ecological environment caused by excessive application of pesticides and fertilizers to the agricultural ecological environment. Discovery of the mechanism of biodiversity to control crop diseases can reasonably guide the rational deployment and rotation of different crops and establish optimization combinations of different crops. This review summarizes recent advances of research on molecular, physiological, and ecological mechanisms of biodiversity managing crop diseases, and proposes some research that needs to be strengthened in the future. PMID:23208136

  15. Effects of crop residue on soil and plant water evaporation in a dryland cotton system

    NASA Astrophysics Data System (ADS)

    Lascano, R. J.; Baumhardt, R. L.

    1996-03-01

    Dryland agricultural cropping systems emphasize sustaining crop yields with limited use of fertilizer while conserving both rain water and the soil. Conservation of these resources may be achieved with management systems that retain residues at the soil surface simultaneously modifying both its energy and water balance. A conservation practice used with cotton grown on erodible soils of the Texas High Plains is to plant cotton into chemically terminated wheat residues. In this study, the partitioning of daily and seasonal evapotranspiration ( E t) into soil and plant water evaporation was compared for a conventional and a terminated-wheat cotton crop using the numerical model ENWATBAL. The model was configured to account for the effects of residue on the radiative fluxes and by introducing an additional resistance to latent and sensible heat fluxes derived from measurements of wind speed and vapor conductance from a soil covered with wheat-stubble. Our results showed that seasonal E t was similar in both systems and that cumulative soil water evaporation was 50% of E t in conventional cotton and 31% of E t in the wheat-stubble cotton. Calculated values of E t were in agreement with measured values. The main benefit of the wheat residues was to suppress soil water evaporation by intercepting irradiance early in the growing season when the crop leaf area index (LAI) was low. In semiarid regions LAI of dryland cotton seldom exceeds 2 and residues can improve water conservation. Measured soil temperatures showed that early in the season residues reduced temperature at 0.1 m depth by as much as 5°C and that differences between systems diminished with depth and over time. Residues increased lint yield per unit of E t while not modifying seasonal E t and reducing cumulative soil water evaporation.

  16. The compatibility of a nucleopolyhedrosis virus control with resistance management for Bacillus thuringiensis: co-infection and cross-resistance studies with the diamondback moth, Plutella xylostella.

    PubMed

    Raymond, B; Sayyed, A H; Wright, D J

    2006-10-01

    The use of genetically modified crops expressing Bacillus thuringiensis (Bt) toxins can lead to the reduction in application of broad-spectrum pesticides and an increased opportunity for supplementary biological control. Bt microbial sprays are also used by organic growers or as part of integrated pest management programs that rely on the use of natural enemies. In both applications the evolution of resistance to Bt toxins is a potential problem. Natural enemies (pathogens or insects) acting in combination with toxins can accelerate or decelerate the evolution of resistance to Bt. In the present study we investigated whether the use of a nucleopolyhedrovirus (AcMNPV) could potentially affect the evolution of resistance to the Bt toxin Cry1Ac in Plutella xylostella. At low toxin doses there was evidence for antagonistic interactions between AcMNPV and Cry1Ac resistant and susceptible insects. However, this antagonism was much stronger and more widespread for susceptible larvae; interactions were generally not distinguishable from additive for resistant larvae. Selection for resistance to Cry1Ac in two populations of P. xylostella with differing resistance mechanisms did not produce any correlated changes in resistance to AcMNPV. Stronger antagonistic interactions between Bt and AcMNPV on susceptible rather than resistant larvae can decrease the relative fitness between Bt-resistant and susceptible larvae. These interactions and the lack of cross-resistance between virus and toxin suggest that the use of NPV is compatible with resistance management to Bt products. PMID:16905146

  17. Amaranth: the one and future crop

    SciTech Connect

    Tucker, J.B.

    1986-01-01

    Amaranth, a former Aztec crop, has the advantage of drought tolerance, high nutritional value, using C/sub 4/ carbon fixation, being a domesticable plant having high yields and needing only minor modification of farm equipment. Besides its present use as a health food it could be used as livestock fodder, in baby food, in aerosols and for squalene extraction. Amaranth has the potential to become an economically important crop although more research needs to be done into its breeding, harvesting, growth performance, disease resistance and marketing.

  18. Simulation of crop evapotranspiration and crop coefficient in weighing lysimeters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate quantification of crop evapotranspiration (ET) is critical in optimizing irrigation water productivity, especially, in the semiarid regions of the world where limited rainfall is supplemented by irrigation for profitable crop production. In this context, cropping system models are potential...

  19. Concepts in crop rotations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop rotations have been a part of civilization since the Middle Ages. With colonization of what would become the United States came new crops of tobacco, cotton, and corn, the first two of which would play significant roles in both the economic beginnings and social fabric of the new country, how ...

  20. Success with cover crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cover crops are an important tool for producers interested in improving soil and crop productivity. They help control erosion, improve soil quality, improve soil properties that impact water infiltration and conservation, provide habitat and food for beneficial insects, and provide food for wildlif...

  1. Waves and Crops

    ERIC Educational Resources Information Center

    Bennett, J.

    1973-01-01

    Discusses wave patterns on the surfaces of ripening wheat and barley crops when the wind is moderately strong. Examines the structure of the turbulence over such natural surfaces and conditions under which the crop may be damaged by the wind. (JR)

  2. OVERVIEW OF CROP BIOTECHNOLOGY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of crop biotechnology on outcomes of agricultural practices and economics is readily evidenced by the escalating acreage of genetically engineered crops, all occurring in a relatively short time span. Until the mid 1990s, virtually no acreage was planted with commercial genetically mo...

  3. Crop Sequence Economics in Dynamic Cropping Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    No-till production systems allow more intensified and diversified production in the northern Great Plains; however, this has increased the need for information on improving economic returns through crop sequence selection. Field research was conducted 6 km southwest of Mandan ND to determine the inf...

  4. Controversy over genetically modified organisms: the governing laws and regulations.

    PubMed

    Keatley, K L

    2000-01-01

    Genetically Modified Organisms (GMOs) are increasingly becoming a topic of controversy in the U.S. and abroad. The public is questioning their safety and wanting the products labeled as genetically modified. There are other concerns from some of the scientific world and some government officials and organizations such as the Food & Agricultural Organization (FAO) that question whether adequate research has been done to qualify GMOs as safe for long-term use. Of particular concern are the allergenic properties, a GMO may impart, possible transfer effects of antibiotic resistance (given that antibiotic resistant marker genes are used for many GMOs), the expression of previously unexpressed traits, and the drift of pollen from genetically modified crops. It has also been noted that the laws and regulations governing the biotechnology world are outdated, are not comprehensive, and span too many agencies. The primary agencies currently regulating biotechnology are the U.S. Department of Agriculture (USDA), the Food and Drug Administration (FDA), and the Environmental Protection Agency (EPA). PMID:11710306

  5. Evaluation of TPGS-modified thermo-sensitive Pluronic PF127 hydrogel as a potential carrier to reverse the resistance of P-gp-overexpressing SMMC-7721 cell lines.

    PubMed

    Gao, Lei; Wang, Xiaoqing; Ma, Jianli; Hao, Daifeng; Wei, Pei; Zhou, Liang; Liu, Guiyang

    2016-04-01

    In the present studies locally injectable docetaxel nanocrystals loaded d-alpha tocopheryl polyethylene glycol 1000 succinate-modified Pluronic F127 (DOC-NCs-TPGS-PF127) thermo-sensitive hydrogels were prepared to reverse drug resistance of P-glycoprotein (P-gp)-overexpressing human liver cancer SMMC-7721 tumors. Firstly, DOC nanosuspensions with mean particle size of 196nm were prepared and dispersed into series of mixed solutions containing PF127 and TPGS of different ratios to obtain DOC-NCs-TPGS-PF127 hydrogels. DOC NCs, exhibiting a uniform distribution and very good physical stability during three sol-gel cycles in the hydrogel network, did not influence the gelation temperature. Swelling-dependent release pattern was found for DOC NCs from hydrogels and release profiles could be well fitted by the Peppas equation. MTT test showed that hydrogels containing 0% or 0.1% TPGS had no cytotoxicity against L929 fibroblasts. Both DOC solution and DOC-NCs-TPGS-PF127 hydrogels exhibited obvious cytotoxicity against sensitive SMMC-7721 cells. When resistant SMMC7721 cells were treated, DOC-NCs-TPGS-PF127 hydrogels showed significantly higher cytotoxicity compared with DOC solution and hydrogels containing no TPGS (DOC-NCs-PF127), with markedly lower IC50 and resistant index (RI). After intratumoral injection in SMMC-7721/RT tumor xenograft Balb/c mice model, DOC-NCs-TPGS-PF127 hydrogels exhibited about 5-fold increase and 1.8-fold increase in the inhibition rate of tumor growth compared with intravenous and intratumoral injection of DOC solution, respectively. It could be concluded that TPGS-modified PF127 thermo-sensitive hydrogel was an excellent locally injectable carrier to reverse P-gp overexpression associated multi-drug resistance. PMID:26764117

  6. Multi-toxin resistance enables pink bollworm survival on pyramided Bt cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic crops producing Bacillus thuringiensis (Bt) proteins kill key insect pests, providing economic and environmental benefits. However, the evolution of pest resistance threatens the continued success of such Bt crops. To delay or counter resistance, transgenic plant "pyramids" producing tw...

  7. Identity of Schizaphis species (Hemiptera: Aphididae) in the United Kingdom: Are they a threat to crops?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The greenbug aphid, Schizaphis graminum (Rondani), is a major pest of cereals in some parts of the world and is of particular concern because it can be resistant to some insecticides and overcome the resistance of crops. In the UK it has never been found on crops but an aphid morphologically like t...

  8. DEVELOPMENT OF A MULTI-TIERED INSECT RESISTANCE MANAGEMENT PROGRAM FOR GENETICALLY MODIFIED CORN HYBRIDS EXPRESSING THE PLANT INCORPORATED PROTECTANT, BACILLUS THURINGIENSIS

    EPA Science Inventory

    A significant increase in genetically modified corn planting driven by biofuel demand is expected for the 2007 growing season with future planted acreages approaching 80% of total corn plantings anticipated by 2009. As demand increases, incidence of farmer non-compliance with ma...

  9. Modified cyanobacteria

    DOEpatents

    Vermaas, Willem F J.

    2014-06-17

    Disclosed is a modified photoautotrophic bacterium comprising genes of interest that are modified in terms of their expression and/or coding region sequence, wherein modification of the genes of interest increases production of a desired product in the bacterium relative to the amount of the desired product production in a photoautotrophic bacterium that is not modified with respect to the genes of interest.

  10. The Association between Hematological Parameters and Insulin Resistance Is Modified by Body Mass Index – Results from the North-East Italy MoMa Population Study

    PubMed Central

    Barazzoni, Rocco; Gortan Cappellari, Gianluca; Semolic, Annamaria; Chendi, Enrico; Ius, Mario; Situlin, Roberta; Zanetti, Michela; Vinci, Pierandrea; Guarnieri, Gianfranco

    2014-01-01

    Objective Increments in red blood cell count (RBC), hemoglobin (Hb) and hematocrit (Ht) levels are reportedly associated with higher insulin resistance (IR). Obesity may cause IR, but underlying factors remain incompletely defined, and interactions between obesity, hematological parameters and IR are incompletely understood. We therefore determined whether: 1) BMI and obesity per se are independently associated with higher RBC, hemoglobin and hematocrit; 2) hematological parameters independently predict insulin resistance in obese individuals. Design and Methods We investigated the associations between BMI, hematological parameters and insulin resistance as reflected by homeostasis model assessment (HOMA) in a general population cohort from the North-East Italy MoMa epidemiological study (M/F = 865/971, age = 49±1). Results In all subjects, age-, sex- and smoking-adjusted hematological parameters were positively associated with BMI in linear regression (P<0.05), but not after adjustment for HOMA or waist circumference (WC) and potential metabolic confounders. No associations were found between hematological parameters and BMI in lean, overweight or obese subgroups. Associations between hematological parameters and HOMA were conversely independent of BMI in all subjects and in lean and overweight subgroups (P<0.01), but not in obese subjects alone. Conclusions In a North-East Italy general population cohort, obesity per se is not independently associated with altered RBC, Hb and Ht, and the association between BMI and hematological parameters is mediated by their associations with abdominal fat and insulin resistance markers. High hematological parameters could contribute to identify insulin resistance in non-obese individual, but they do not appear to be reliable insulin resistance biomarkers in obese subjects. PMID:25000394

  11. Trap Crops and Population Management of Globodera tabacum tabacum.

    PubMed

    Lamondia, J A

    1996-06-01

    Tobacco, eastern black nightshade, and tomato were grown for 3 to 13 weeks to assess differences in invasion, development, and soil density of Globodera tabacum tabacum (tobacco cyst nematode) in field plots and microplots over three seasons. Tobacco cyst nematodes invaded roots of resistant and susceptible tobacco, nightshade, and tomato. Nematode development was fastest in nightshade and slowest in tomato, and few adults developed in roots of nematode-resistant tobacco. Soil populations of tobacco cyst nematodes were reduced up to 80% by destroying nightshade or susceptible tobacco grown for 3 to 6 weeks. Nematode populations were reduced up to 96% by destroying tomato or resistant tobacco grown for 3 to 6 weeks. Timing of crop destruction was less critical with tomato and resistant tobacco, as nematode populations did not increase after 13 weeks of growth. These studies demonstrate that trap cropping, through crop destruction, can significantly reduce G. t. tabacum populations. PMID:19277140

  12. Regulatory Protein OmpR Influences the Serum Resistance of Yersinia enterocolitica O:9 by Modifying the Structure of the Outer Membrane

    PubMed Central

    Skorek, Karolina; Raczkowska, Adrianna; Dudek, Bartłomiej; Miętka, Katarzyna; Guz-Regner, Katarzyna; Pawlak, Aleksandra; Klausa, Elżbieta; Bugla-Płoskońska, Gabriela; Brzostek, Katarzyna

    2013-01-01

    The EnvZ/OmpR two-component system constitutes a regulatory pathway involved in bacterial adaptive responses to environmental cues. Our previous findings indicated that the OmpR regulator in Yersinia enterocolitica O:9 positively regulates the expression of FlhDC, the master flagellar activator, which influences adhesion/invasion properties and biofilm formation. Here we show that a strain lacking OmpR grown at 37°C exhibits extremely high resistance to the bactericidal activity of normal human serum (NHS) compared with the wild-type strain. Analysis of OMP expression in the ompR mutant revealed that OmpR reciprocally regulates Ail and OmpX, two homologous OMPs of Y. enterocolitica, without causing significant changes in the level of YadA, the major serum resistance factor. Analysis of mutants in individual genes belonging to the OmpR regulon (ail, ompX, ompC and flhDC) and strains lacking plasmid pYV, expressing YadA, demonstrated the contribution of the respective proteins to serum resistance. We show that Ail and OmpC act in an opposite way to the OmpX protein to confer serum resistance to the wild-type strain, but are not responsible for the high resistance of the ompR mutant. The serum resistance phenotype of ompR seems to be multifactorial and mainly attributable to alterations that potentiate the function of YadA. Our results indicate that a decreased level of FlhDC in the ompR mutant cells is partly responsible for the serum resistance and this effect can be suppressed by overexpression of flhDC in trans. The observation that the loss of FlhDC enhances the survival of wild-type cells in NHS supports the involvement of FlhDC regulator in this phenotype. In addition, the ompR mutant exhibited a lower level of LPS, but this was not correlated with changes in the level of FlhDC. We propose that OmpR might alter the susceptibility of Y. enterocolitica O:9 to complement-mediated killing through remodeling of the outer membrane. PMID:24260242

  13. C-5-Modified Tetrahydropyrano-Tetrahydofuran-Derived Protease Inhibitors (PIs) Exert Potent Inhibition of the Replication of HIV-1 Variants Highly Resistant to Various PIs, including Darunavir

    PubMed Central

    Aoki, Manabu; Hayashi, Hironori; Yedidi, Ravikiran S.; Martyr, Cuthbert D.; Takamatsu, Yuki; Aoki-Ogata, Hiromi; Nakamura, Teruya; Nakata, Hirotomo; Das, Debananda; Yamagata, Yuriko; Ghosh, Arun K.

    2015-01-01

    ABSTRACT We identified three nonpeptidic HIV-1 protease inhibitors (PIs), GRL-015, -085, and -097, containing tetrahydropyrano-tetrahydrofuran (Tp-THF) with a C-5 hydroxyl. The three compounds were potent against a wild-type laboratory HIV-1 strain (HIV-1WT), with 50% effective concentrations (EC50s) of 3.0 to 49 nM, and exhibited minimal cytotoxicity, with 50% cytotoxic concentrations (CC50) for GRL-015, -085, and -097 of 80, >100, and >100 μM, respectively. All the three compounds potently inhibited the replication of highly PI-resistant HIV-1 variants selected with each of the currently available PIs and recombinant clinical HIV-1 isolates obtained from patients harboring multidrug-resistant HIV-1 variants (HIVMDR). Importantly, darunavir (DRV) was >1,000 times less active against a highly DRV-resistant HIV-1 variant (HIV-1DRVRP51); the three compounds remained active against HIV-1DRVRP51 with only a 6.8- to 68-fold reduction. Moreover, the emergence of HIV-1 variants resistant to the three compounds was considerably delayed compared to the case of DRV. In particular, HIV-1 variants resistant to GRL-085 and -097 did not emerge even when two different highly DRV-resistant HIV-1 variants were used as a starting population. In the structural analyses, Tp-THF of GRL-015, -085, and -097 showed strong hydrogen bond interactions with the backbone atoms of active-site amino acid residues (Asp29 and Asp30) of HIV-1 protease. A strong hydrogen bonding formation between the hydroxyl moiety of Tp-THF and a carbonyl oxygen atom of Gly48 was newly identified. The present findings indicate that the three compounds warrant further study as possible therapeutic agents for treating individuals harboring wild-type HIV and/or HIVMDR. IMPORTANCE Darunavir (DRV) inhibits the replication of most existing multidrug-resistant HIV-1 strains and has a high genetic barrier. However, the emergence of highly DRV-resistant HIV-1 strains (HIVDRVR) has recently been observed in vivo and in

  14. Using cover crops and cropping systems for nitrogen management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The reasons for using cover crops and optimized cropping sequences to manage nitrogen (N) are to maximize economic returns, improve soil quality and productivity, and minimize losses of N that might adversely impact environmental quality. Cover crops and cropping systems’ effects on N management are...

  15. Cover crop biomass harvest for bioenergy: implications for crop productivity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Winter cover crops, such as rye (Secale cereale), are usually used in conservation agriculture systems in the Southeast. Typically, the cover crop is terminated two to three weeks before planting the summer crop, with the cover biomass left on the soil surface as a mulch. However, these cover crops ...

  16. Structural levels of deformation and failure of heat-resistant 12Cr1MoV steel modified by vacuum arc treatment by Zr{sup +} ion beam

    SciTech Connect

    Vlasov, I. V. E-mail: svp@ispms.tsc.ru; Panin, S. V. E-mail: svp@ispms.tsc.ru; Ovechkin, B. B.; Sergeev, V. P.

    2014-11-14

    Study of structural changes occurring in the surface layer modified by ion-beam irradiation was carried out by means of optical, scanning and transmission electron microscopy. It was shown that irradiation induces the structure modification not only in the surface layer, but along the entire cross section of 1 mm thick specimens. It was elucidated that the complex pattern of structural changes is responsible for the pronounced variation of mechanical properties taking place under static tension and cyclic alternating bending.

  17. Combinatorial-Designed Epidermal Growth Factor Receptor-Targeted Chitosan Nanoparticles for Encapsulation and Delivery of Lipid-Modified Platinum Derivatives in Wild-Type and Resistant Non-Small-Cell Lung Cancer Cells.

    PubMed

    Nascimento, Ana Vanessa; Singh, Amit; Bousbaa, Hassan; Ferreira, Domingos; Sarmento, Bruno; Amiji, Mansoor M

    2015-12-01

    Development of efficient and versatile drug delivery platforms to overcome the physical and biological challenges in cancer therapeutics is an area of great interest, and novel materials are actively sought for such applications. Recent strides in polymer science have led to a combinatorial approach for generating a library of materials with different functional identities that can be "mixed and matched" to attain desired characteristics of a delivery vector. We have applied the combinatorial design to chitosan (CS), where the polymer backbone has been modified with polyethylene glycol, epidermal growth factor receptor-binding peptide, and lipid derivatives of varying chain length to encapsulate hydrophobic drugs. Cisplatin, cis-([PtCl2(NH3)2]), is one of the most potent chemotherapy drugs broadly administered for cancer treatment. Cisplatin is a hydrophilic drug, and in order for it to be encapsulated in the developed nanosystems, it was modified with lipids of varying chain length. The library of four CS derivatives and six platinum derivatives was self-assembled in aqueous medium and evaluated for physicochemical characteristics and cytotoxic effects in platinum-sensitive and -resistant lung cancer cells. The results show that the lipid-modified platinate encapsulation into CS nanoparticles significantly improved cellular cytotoxicity of the drug. In this work, we have also reinforced the idea that CS is a multifaceted system that can be as successful in delivering small molecules as it has been as a nucleic acids carrier. PMID:26523837

  18. Transgenics in crops

    NASA Technical Reports Server (NTRS)

    Li, Y.; Wu, Y. H.; McAvoy, R.; Duan, H.

    2001-01-01

    With rapid world population growth and declining availability of fresh water and arable land, a new technology is urgently needed to enhance agricultural productivity. Recent discoveries in the field of crop transgenics clearly demonstrate the great potential of this technology for increasing food production and improving food quality while preserving the environment for future generations. In this review, we briefly discuss some of the recent achievements in crop improvement that have been made using gene transfer technology.

  19. Radioactivity in food crops

    SciTech Connect

    Drury, J.S.; Baldauf, M.F.; Daniel, E.W.; Fore, C.S.; Uziel, M.S.

    1983-05-01

    Published levels of radioactivity in food crops from 21 countries and 4 island chains of Oceania are listed. The tabulation includes more than 3000 examples of 100 different crops. Data are arranged alphabetically by food crop and geographical origin. The sampling date, nuclide measured, mean radioactivity, range of radioactivities, sample basis, number of samples analyzed, and bibliographic citation are given for each entry, when available. Analyses were reported most frequently for /sup 137/Cs, /sup 40/K, /sup 90/Sr, /sup 226/Ra, /sup 228/Ra, plutonium, uranium, total alpha, and total beta, but a few authors also reported data for /sup 241/Am, /sup 7/Be, /sup 60/Co, /sup 55/Fe, /sup 3/H, /sup 131/I, /sup 54/Mn, /sup 95/Nb, /sup 210/Pb, /sup 210/Po, /sup 106/Ru, /sup 125/Sb, /sup 228/Th, /sup 232/Th, and /sup 95/Zr. Based on the reported data it appears that radioactivity from alpha emitters in food crops is usually low, on the order of 0.1 Bq.g/sup -1/ (wet weight) or less. Reported values of beta radiation in a given crop generally appear to be several orders of magnitude greater than those of alpha emitters. The most striking aspect of the data is the great range of radioactivity reported for a given nuclide in similar food crops with different geographical origins.

  20. Lantibiotic resistance.

    PubMed

    Draper, Lorraine A; Cotter, Paul D; Hill, Colin; Ross, R Paul

    2015-06-01

    The dramatic rise in the incidence of antibiotic resistance demands that new therapeutic options will have to be developed. One potentially interesting class of antimicrobials are the modified bacteriocins termed lantibiotics, which are bacterially produced, posttranslationally modified, lanthionine/methyllanthionine-containing peptides. It is interesting that low levels of resistance have been reported for lantibiotics compared with commercial antibiotics. Given that there are very few examples of naturally occurring lantibiotic resistance, attempts have been made to deliberately induce resistance phenotypes in order to investigate this phenomenon. Mechanisms that hinder the action of lantibiotics are often innate systems that react to the presence of any cationic peptides/proteins or ones which result from cell well damage, rather than being lantibiotic specific. Such resistance mechanisms often arise due to altered gene regulation following detection of antimicrobials/cell wall damage by sensory proteins at the membrane. This facilitates alterations to the cell wall or changes in the composition of the membrane. Other general forms of resistance include the formation of spores or biofilms, which are a common mechanistic response to many classes of antimicrobials. In rare cases, bacteria have been shown to possess specific antilantibiotic mechanisms. These are often species specific and include the nisin lytic protein nisinase and the phenomenon of immune mimicry. PMID:25787977