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Genetically Modified Plants (genetically + modified_plant)
Selected AbstractsGreenhouse Gas Profile of a Plastic Material Derived from a Genetically Modified PlantJOURNAL OF INDUSTRIAL ECOLOGY, Issue 3 2000Devdatt Kurdikar Abstract: This article reports an assessment of the global warming potential associated with the life cycle of a biopolymer (poly(hydroxyalkanoate) or PHA) produced in genetically engineered corn developed by Monsanto. The grain corn is harvested in a conventional manner, and the polymer is extracted from the corn stover (i.e., residues such as stalks, leaves and cobs), which would be otherwise left on the field. While corn farming was assessed based on current practice, four different hypothetical PHA production scenarios were tested for the extraction process. Each scenario differed in the energy source used for polymer extraction and compounding, and the results were compared to polyethylene (PE). The first scenario involved burning of the residual biomass (primarily cellulose) remaining after the polymer was extracted from the stover. In the three other scenarios, the use of conventional energy sources of coal, oil, and natural gas were investigated. This study indicates that an integrated system, wherein biomass energy from corn stover provides energy for polymer processing, would result in a better greenhouse gas profile for PHA than for PE. However, plant-based PHA production using fossil fuel sources provides no greenhouse gas advantage over PE, in fact scoring worse than PE. These results are based on a "cradle-to-pellet" modeling as the PHA end-of-life was not quantitatively studied due to complex issues surrounding the actual fate of postconsumer PHA. [source] Evaluation of a Non-Targeted "Omic" Approach in the Safety Assessment of Genetically Modified PlantsPLANT BIOLOGY, Issue 5 2006S. B. Metzdorff Abstract: Genetically modified plants must be approved before release in the European Union, and the approval is generally based upon a comparison of various characteristics between the transgenic plant and a conventional counterpart. As a case study, focusing on safety assessment of genetically modified plants, we here report the development and characterisation of six independently transformed Arabidopsis thaliana lines modified in the flavonoid biosynthesis. Analyses of integration events and comparative analysis for characterisation of the intended effects were performed by PCR, quantitative Real-time PCR, and High Performance Liquid Chromatography. Analysis by cDNA microarray was used as a non-targeted approach for the identification of potential unintended effects caused by the transformation. The results revealed that, although the transgenic lines possessed different types of integration events, no unintended effects were identified. However, we found that the majority of genes showing differential expression were identified as stress-related genes and that environmental conditions had a large impact on the expression of several genes, proteins, and metabolites. We suggest that the microarray approach has the potential to become a useful tool for screening of unintended effects, but state that it is crucial to have substantial information on the natural variation in traditional crops in order to be able to interpret "omics" data correctly within the framework of food safety assessment strategies of novel plant varieties, including genetically modified plant varieties. [source] A metapopulation model for the introgression from genetically modified plants into their wild relativesEVOLUTIONARY APPLICATIONS (ELECTRONIC), Issue 2 2009Patrick G. Meirmans Abstract Most models on introgression from genetically modified (GM) plants have focused on small spatial scales, modelling gene flow from a field containing GM plants into a single adjacent population of a wild relative. Here, we present a model to study the effect of introgression from multiple plantations into the whole metapopulation of the wild relative. The most important result of the model is that even very low levels of introgression and selection can lead to a high probability that the transgene goes to fixation in the metapopulation. Furthermore, the overall frequency of the transgene in the metapopulation, after a certain number of generations of introgression, depends on the population dynamics. If there is a high rate of migration or a high rate of population turnover, the overall transgene frequency is much higher than with lower rates. However, under an island model of population structure, this increased frequency has only a very small effect on the probability of fixation of the transgene. Considering these results, studies on the potential ecological risks of introgression from GM plants should look not only at the rate of introgression and selection acting on the transgene, but also at the metapopulation dynamics of the wild relative. [source] Human safety and genetically modified plants: a review of antibiotic resistance markers and future transformation selection technologiesJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2005D.A. Goldstein [source] Methods for evaluating human impact on soil microorganisms based on their activity, biomass, and diversity in agricultural soilsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 3 2006Rainer Georg Joergensen Abstract The present review is focused on microbiological methods used in agricultural soils accustomed to human disturbance. Recent developments in soil biology are analyzed with the aim of highlighting gaps in knowledge, unsolved research questions, and controversial results. Activity rates (basal respiration, N mineralization) and biomass are used as overall indices for assessing microbial functions in soil and can be supplemented by biomass ratios (C : N, C : P, and C : S) and eco-physiological ratios (soil organic C : microbial-biomass C, qCO2, qNmin). The community structure can be characterized by functional groups of the soil microbial biomass such as fungi and bacteria, Gram-negative and Gram-positive bacteria, or by biotic diversity. Methodological aspects of soil microbial indices are assessed, such as sampling, pretreatment of samples, and conversion factors of data into biomass values. Microbial-biomass C (µg (g soil),1) can be estimated by multiplying total PLFA (nmol (g soil),1) by the FPLFA -factor of 5.8 and DNA (µg (g soil),1) by the FDNA -factor of 6.0. In addition, the turnover of the soil microbial biomass is appreciated as a key process for maintaining nutrient cycles in soil. Examples are briefly presented that show the direction of human impact on soil microorganisms by the methods evaluated. These examples are taken from research on organic farming, reduced tillage, de-intensification of land-use management, degradation of peatland, slurry application, salinization, heavy-metal contamination, lignite deposition, pesticide application, antibiotics, TNT, and genetically modified plants. [source] The definition, source, manifestation and assessment of unintended effects in genetically modified plantsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2008Ping-Jian Deng Abstract At present, there is consensus among many relevant international agencies that unintended effects should be paid particular attention in the process of edible safety assessment of genetically modified plants (GMPs) and their products, especially in regard to some long-term and potential food safety issues. However, with respect to the current risk assessment of GMPs, serious dissension on the apprehension of unintended effects exists. The present paper interprets and systematically analyses this dissension in order to review development on the definition, source and manifestation of unintended effects in GMPs. First, differences in the various concepts of unintended effect are discussed and compared. Then the mechanisms whereby unintended effects may arise during GMP breeding are analysed and the main unexpected variation manifestations in GMPs are presented. With regard to the safety assessment of unintended effects in GMPs, the current evaluation strategy, detection methods and several assessment cases are expounded. In addition, the unique assessment standard for unintended effects in GMPs in China is outlined. Copyright © 2008 Society of Chemical Industry [source] Evaluation of a Non-Targeted "Omic" Approach in the Safety Assessment of Genetically Modified PlantsPLANT BIOLOGY, Issue 5 2006S. B. Metzdorff Abstract: Genetically modified plants must be approved before release in the European Union, and the approval is generally based upon a comparison of various characteristics between the transgenic plant and a conventional counterpart. As a case study, focusing on safety assessment of genetically modified plants, we here report the development and characterisation of six independently transformed Arabidopsis thaliana lines modified in the flavonoid biosynthesis. Analyses of integration events and comparative analysis for characterisation of the intended effects were performed by PCR, quantitative Real-time PCR, and High Performance Liquid Chromatography. Analysis by cDNA microarray was used as a non-targeted approach for the identification of potential unintended effects caused by the transformation. The results revealed that, although the transgenic lines possessed different types of integration events, no unintended effects were identified. However, we found that the majority of genes showing differential expression were identified as stress-related genes and that environmental conditions had a large impact on the expression of several genes, proteins, and metabolites. We suggest that the microarray approach has the potential to become a useful tool for screening of unintended effects, but state that it is crucial to have substantial information on the natural variation in traditional crops in order to be able to interpret "omics" data correctly within the framework of food safety assessment strategies of novel plant varieties, including genetically modified plant varieties. [source] | |||||||||||||