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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Genetiškai modifikuotų augalų paplitimo ir poveikio aplinkai analizė ir Lietuvos gyventojų požiūrio apžvalga / The analysis of genetically modified plants spread and environment impact and the analysis of lithuanian people attitude

Dževečkaitė, Neringa 08 September 2009 (has links)
Genetiškai modifikuoti augalai kuriami siekiant sukurti naujas veisles, t.y pagerinti augalų technologines ir maistines savybes. Genų inžinerijos metodais sukurta tūkstančiai naujų veislių. Tai augalai atsparūs herbicidams ir insekticidams. Nors pirmieji komerciniai GM pasėliai užauginti 1994 metais (pomidorai), 1996 metai laikomi metais, kuomet GM pasėliai pradėti auginti plačiu mastu (1,66 milijono hektarų). Nuo tada GM pasėlių auginimas augo labai staigiai ir 2005 metais tokie pasėliai užėmė 87,2 milijonus hektarų ploto. Didžiausią GM pasėlių plotą užima: soja, javai, medvilnė ir rapsai. Genetiškai modifikuoti augalai – produktas naujų technologijų. Tokie ugalai įgauna savybių kurios jiems iki tol nebuvo būdingos. GM maisto saugumas dar nėra įroditas. Tyrimai nebuvo ilgalaikiai ir pakankami. Šie augalai gali būti pavojingi tiek žmogaus sveikatai, tiek ir aplinkai. Siekiant užtikrinti, kad GM augalai ir GM produktai atitiktų nustatytas žmonių ir gyvūnų saugos bei aplinkos apsaugos reikalavimus, būtina atlikti rizikos aplinkai, žemės ūkiui, gyvūnų ir žmonių sveikatai įvertinimą ir vykdyti monitoringą. / Genetically modified plants (GM plants) are being engineered in order to develop different new species, i.e. enhancing technological and nutrient traits. There have been engineered thousands of new plants species, employed genetic engineering methods. The dominant plants are GM herbicide tolerant plants and GM insecticide tolerant plants. Although the first commercial GM crops were planted in 1994 (tomatoes), 1996 was the first year in which a significant area 1.66 mln.ha of crops were planted containing GM traits. Since then there has been a dramatic increase in plantings and by 2005, the glogal planted area reached almost 87,2 million hectares. Almost all of the global GM crop area derives from soybeans, corn, cotton and canola. Genetically modified plants are products of new technologies. Plants develop new characteristics which were not typical of them before. Safety of GM food has not been proved. The research wasn’t long-term and sufficient enough. This plants can be dangerous for human health and for environment. In order to ensure the requirement established for safe handling, use and control of the GM plants and GM products for human and animal health end environmental protection, it is necessary to perform risk assessment posed by GM plants and GM products to the environment, agriculture and human health and to organize constant monitoring.
2

WRINKLED1, A Ubiquitous Regulator in Oil Accumulating Tissues from Arabidopsis Embryos to Oil Palm Mesocarp

Ma, Wei, Kong, Que, Arondel, Vincent, Kilaru, Aruna, Bates, Philip D., Thrower, Nicholas A., Benning, Christoph, Ohlrogge, John B. 26 July 2013 (has links)
WRINKLED1 (AtWRI1) is a key transcription factor in the regulation of plant oil synthesis in seed and non-seed tissues. The structural features of WRI1 important for its function are not well understood. Comparison of WRI1 orthologs across many diverse plant species revealed a conserved 9 bp exon encoding the amino acids “VYL”. Site-directed mutagenesis of amino acids within the ‘VYL’ exon of AtWRI1 failed to restore the full oil content of wri1-1 seeds, providing direct evidence for an essential role of this small exon in AtWRI1 function. Arabidopsis WRI1 is predicted to have three alternative splice forms. To understand expression of these splice forms we performed RNASeq of Arabidopsis developing seeds and queried other EST and RNASeq databases from several tissues and plant species. In all cases, only one splice form was detected and VYL was observed in transcripts of all WRI1 orthologs investigated. We also characterized a phylogenetically distant WRI1 ortholog (EgWRI1) as an example of a non-seed isoform that is highly expressed in the mesocarp tissue of oil palm. The C-terminal region of EgWRI1 is over 90 amino acids shorter than AtWRI1 and has surprisingly low sequence conservation. Nevertheless, the EgWRI1 protein can restore multiple phenotypes of the Arabidopsis wri1-1 loss-of-function mutant, including reduced seed oil, the “wrinkled” seed coat, reduced seed germination, and impaired seedling establishment. Taken together, this study provides an example of combining phylogenetic analysis with mutagenesis, deep-sequencing technology and computational analysis to examine key elements of the structure and function of the WRI1 plant transcription factor.
3

Expression Of Trichoderma Reesei Beta]-mannanase In Tobacco Chloroplasts And Its Utilization In Lignocellulosic Woody Biomass Hydrolysis

Agrawal, Pankaj M 01 January 2011 (has links)
Lignocellulosic ethanol offers a promising alternative to conventional fossil fuels. One among the major limitations in the lignocellulosic biomass hydrolysis is unavailability of efficient and environmentally biomass degrading technologies. Plantbased production of these enzymes on large scale offers a cost effective solution. Cellulases, hemicellulases including mannanases and other accessory enzymes are required for conversion of lignocellulosic biomass into fermentable sugars. β- mannanase catalyzes endo-hydrolysis of the mannan backbone, a major constituent of woody biomass. In this study, man1 gene encoding β-mannanase was isolated from Trichoderma reesei and expressed via the chloroplast genome. PCR and Southern hybridization analysis confirmed the site-specific transgene integration into the tobacco chloroplast genomes and homoplasmy. Transplastomic plants were fertile and set viable seeds. Germination of seeds showed inheritance of transgenes into the progeny without Mendelian segregation. Expression of the endo-β-mannanase gene for the first time in plants facilitated its characterization for use in enhanced lignocellulosic biomass hydrolysis. Gel diffusion assay for endo-β-mannanase showed the zone of clearance confirming functionality of chloroplast-derived mannanase. Endo-β-mannanase expression levels reached up to 25 units per gram of leaf (fresh weight). Chloroplastderived mannanase had higher temperature stability (40 °C to 70 °C) and wider pH optima (pH 3.0 to 7.0) than E.coli enzyme extracts. Plant crude extracts showed 6-7 fold iv higher enzyme activity than E.coli extracts due to the formation of disulfide bonds in chloroplasts, thereby facilitating their direct utilization in enzyme cocktails without any purification. Chloroplast-derived mannanase when added to the enzyme cocktail containing a combination of different enzymes yielded 20% more glucose equivalents from pinewood than the cocktail without mannanase. Our results demonstrate that chloroplast-derived mannanase is an important component of enzymatic cocktail for woody biomass hydrolysis and should provide a cost-effective solution for its diverse applications in the paper, oil, pharmaceutical, coffee and detergent industries.
4

IMPACTO DE ALGODÃO GENETICAMENTE MODIFICADO RESISTENTE A INSETOS SOBRE A ENTOMOFAUNA DE SOLO

Dutra, Carla Cristina 30 March 2009 (has links)
Made available in DSpace on 2016-02-26T14:53:12Z (GMT). No. of bitstreams: 1 CarlaCristinaDutra.pdf: 1092589 bytes, checksum: 04438f8333358adca1827a37834f4d61 (MD5) Previous issue date: 2009-03-30 / Genetic engineering has created genetically modified (GM) varieties of many crops that express the toxin from the bacterium Cry Bacillus thuringiensis Berliner (Bt). The Cry toxin has insecticidal properties, is synthesized during growth of the plant, and can be expressed in any part of it. To evaluate the impact of this technology on the environment, this study aimed to find the effect of GM cotton resistant to insects on the fauna of Formicidae and Coleoptera. The field sample was a commercial area located in the municipality of Maracajú, Mato Grosso do Sul, Brazil. There were two treatments: Bt cotton and non-Bt cotton, and 20 samples were taken in each treatment during the reproductive period of cotton in the 2007/2008 crop season. The samplings were done by interception pitfall traps. It was used the paired t test for each day of collection to compare the occurrence of species in both treatments. Seeking to obtain gradients of community structure of Formicidae and Coleoptera based on species composition, it was used the technique of ordering by hybrid multidimensional scaling (HMDS). The studied Bt cotton area negatively affected the fauna of Formicidae, because of the species richness in Bt cotton was lower when compared to non-Bt cotton, and the species of this family occurred in non-Bt crops were different from those presented in Bt. The fauna of Coleoptera was also affected by Bt crop, as the species that make up the community assessed in Bt crops are different from those that make the non-Bt crop. The fact that negative results were observed regarding the impact on entomofauna in an area with little time under cultivation of Bt cotton, strengthens the possibility of further changes in the long term / A engenharia genética tem criado variedades geneticamente modificadas (GM) de muitos cultivos que expressam a toxina Cry da bactéria Bacillus thuringiensis Berliner (Bt). Essa toxina tem propriedades inseticidas e é sintetizada durante o crescimento da planta, podendo ser expressa em qualquer parte da mesma. Visando avaliar os impactos dessa tecnologia no ambiente, neste trabalho avaliamos o efeito do algodão GM resistente a insetos sobre a fauna de Formicidae e Coleoptera de solo. O experimento foi conduzido em uma área comercial situada no município de Maracajú, Mato Grosso do Sul, Brasil. Sendo avaliados dois tratamentos: algodão Bt e algodão não-Bt. Foram realizadas 20 amostras em cada tratamento, durante o período reprodutivo do algodoeiro na safra de 2007/2008. A amostragem foi realizada através de armadilhas de interceptação do tipo pitfall modificada. Para a análise da riqueza de espécies utilizou-se o teste t pareado por dia de coleta para comparar a ocorrência das espécies nos dois tratamentos. Buscando obter gradientes da estrutura da comunidade de Formicidae e Coleoptera baseada na composição de espécies, foi utilizada a técnica de ordenação por escalonamento multidimensional híbrido (HMDS). O algodão Bt da área estudada afetou negativamente a fauna de Formicidae, pois a riqueza de espécies no algodão Bt foi inferior quando comparada ao algodão não-Bt. As espécies de formigas ocorrentes no cultivo não-Bt foram diferentes daquelas presentes no Bt. A fauna de Coleoptera também foi afetada pelo cultivo Bt, já que as espécies que compõe a comunidade avaliada no cultivo Bt foram diferentes daquelas que compõe a cultura não-Bt. O fato de terem sido observados resultados negativos a respeito do impacto sobre a entomofauna em uma área com pouco tempo de cultivo de algodão Bt, indica a possibilidade de efeitos ainda maiores em longo prazo
5

Geneticky modifikované rostliny ve vztahu k řešení problematiky globálních klimatických změn / Genetically modified plants in relation to solving the issue of global climate changes

Nedělová, Jana January 2014 (has links)
The theoretical part of the diploma thesis summarizes basic facts related to the global climate change and provides up-to-date knowledge on the issue of genetically modified plants more resistant to stress factors of environment, including specific examples of strategies regarding preparation of genetically modified plants resistant particularly to abiotic stress. Although genetically modified plants and global climate changes belong to very important and current issue which public and foremost young generation should be sufficiently aware of, contemporary biology books and high school framework educational program pay to the issue very little attention. Therefore, the goal of this thesis is not only to summarize the basic facts and current knowledge regarding this issue but mainly to handle the issue in didactic level in the form of activating learning tasks. There were 28 learning tasks created in the thesis that gradually in unconventional way familiarize students with the issue of genetically modified plants and with the impacts of climate changes. Students must actively acquire information from accompanying materials to address the tasks properly, think critically over them, utilizing acquired knowledge and experience from the past to some extent. Fourteen tasks were chosen from the file created which...

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