Publications by authors named "Sophia Biemelt"

Plants possess two different types of phosphofructokinases, an ATP-dependent (PFK) and a pyrophosphate-dependent form (PFP). While plant PFPs have been investigated in detail, cDNA clones coding for PFK have not been identified in Arabidopsis thaliana. Searching the A.

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Plant genetic engineering has the potential to introduce new allergenic proteins into foods but, at the same time, it can be used to remove established allergens. Here, we report the molecular characterization of Lyc e 3, a new tomato (Lycopersicon esculentum) allergen, and the efficient down-regulation of its expression in transgenic tomato plants. Following the identification of an immunoglobulin E (IgE)-binding 9-kDa polypeptide in tomato peel, designated Lyc e 3, its partial amino acid sequence was determined by N-terminal protein sequencing.

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Background: Profilin is a small actin-binding protein that contributes to the allergenic potency of many fruits and vegetables, including tomato. Two highly similar genes encoding tomato profilin have been isolated and designated as allergen Lyc e 1.01 and Lyc e 1.

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Background: Today, for patients with food allergy, the only possibility to prevent allergic reactions is avoidance of the allergenic food. Genetic engineering of hypoallergenic plants by means of RNA interference (RNAi) could be an approach to improve the quality of life of subjects with food allergy.

Objectives: We sought to achieve stable inhibition of expression of the allergenic nonspecific lipid transfer protein Lyc e 3 in tomato and to analyze the reduction of allergenicity in vitro by using histamine release assays and in vivo by using skin prick tests with transgenic tomato fruits.

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The aim of this work was to investigate the importance of cytosolic phosphorylating glyceraldehyde 3-phosphate dehydrogenase (GAPC) in potato carbohydrate metabolism. For this purpose, the cytosolic isoform of phosphorylating GAPC was cloned and used for an antisense approach to generate transgenic potato plants that exhibited constitutively decreased GAPDH activity. Potato lines with decreased activities of phosphorylating GAPC exhibited no major changes in either whole-plant or tuber morphology.

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Different formae speciales of the grass powdery mildew fungus Blumeria graminis undergo basic-compatible or basic-incompatible (nonhost) interactions with barley. Background resistance in compatible interactions and nonhost resistance require common genetic and mechanistic elements of plant defense. To build resources for differential screening for genes that potentially distinguish a compatible from an incompatible interaction on the level of differential gene expression of the plant, we constructed eight dedicated cDNA libraries, established 13.

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Plant growth and development is dependent on coordinated assimilate production, distribution and allocation. Application of biochemical and molecular techniques substantially contributed to a better understanding of these processes, although the underlying regulatory mechanisms are still not fully elucidated and attempts to improve crop yield by modulating carbon partitioning were only partially successful. Plant pathogens also interfere with source-sink interaction.

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Background And Aims: The aim of this study was to investigate the importance of pyrophosphate (PPi) for plant metabolism and survival under low oxygen stress. Responses of roots of wild-type potato plants were compared with roots of transgenic plants containing decreased amounts of PPi as a result of the constitutive expression of Escherichia coli pyrophosphatase in the cytosol.

Methods: For the experiments, roots of young wild-type and transgenic potato plants growing in nutrient solution were flushed for 4 d with nitrogen, and subsequently metabolite contents as well as enzyme activities of the glycolytic pathway were determined.

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Gibberellins (GAs) are involved in regulation of many aspects during plant development. To investigate the impact of altered GA levels on plant growth and metabolism, transgenic tobacco (Nicotiana tabacum) plants have been engineered to express either a GA20-oxidase (AtGA20-ox) or a GA2-oxidase (AtGA2-ox) gene from Arabidopsis under control of the cauliflower mosaic virus 35S promoter. Resulting plants were characterized by elongated or stunted shoot growth, respectively, indicating changes in the content of bioactive GAs.

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Cervical cancer is linked to infection with human papillomaviruses (HPV) and is the third most common cancer among women worldwide. There is a strong demand for the development of an HPV preventive vaccine. Transgenic plants expressing the HPV major capsid protein L1 could be a system to produce virus-like particles for prophylactic vaccination or could even be used as edible vaccines to induce an L1-specific prophylactic immune response.

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