Joachim Fisahn

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A larger proportion of the fixed carbon is retained as starch in the leaf in short days, providing a larger store to support metabolism and carbon export during the long night. The mechanisms that facilitate this adjustment of the sink-source balance are unknown. Starchless pgm mutants were analysed to discover responses that are triggered when diurnal(More)
Plants grow in a light/dark cycle. We have investigated how growth is buffered against the resulting changes in the carbon supply. Growth of primary roots of Arabidopsis seedlings was monitored using time-resolved video imaging. The average daily rate of growth is increased in longer light periods or by addition of sugars. It responds slowly over days when(More)
Early detection of salt stress is vital for plant survival and growth. Still, the molecular processes controlling early salt stress perception and signaling are not fully understood. Here, we identified salt-responsive ERF1 (SERF1), a rice (Oryza sativa) transcription factor (TF) gene that shows a root-specific induction upon salt and hydrogen peroxide(More)
Plants respond to various abiotic stimuli by activation and propagation of fast electrical signals, action potentials. To resolve the temporal increase in cytosolic Ca(2)(+) during the action potentials of higher plants, we regenerated transgenic potato plants that expressed the Ca(2)(+) photoprotein apoaequorin. These genetically engineered potato plants(More)
Experiments were performed on three abscisic acid (ABA)deficient tomato (Lycopersicon esculentum Mill.) mutants, notabilis, flacca, and sitiens, to investigate the role of ABA and jasmonic acid (JA) in the generation of electrical signals and Pin2 (proteinase inhibitor II) gene expression. We selected these mutants because they contain different levels of(More)
Metabolite, protein, and transcript analysis at the cellular level gives unparalleled insight into the complex roles tissues play in the plant system. However, while capillary electrophoresis and PCR amplification strategies make the profiling of metabolites and transcripts in specific cell types possible, the profiling of proteins in small samples(More)
Transgenic tomato (Solanum lycopersicum) plants expressing a fragment of a fumarate hydratase (fumarase) gene in the antisense orientation and exhibiting considerable reductions in the mitochondrial activity of this enzyme show impaired photosynthesis. The rate of the tricarboxylic acid cycle was reduced in the transformants relative to the other major(More)
; Plants respond to various abiotic stimuli by activation and propagation of fast electrical signals, action potentials. To resolve the temporal increase in cytosolic Ca during the action potentials of higher plants, we regenerated transgenic potato plants that expressed the Ca photoprotein apoaequorin. These genetically engineered potato plants were used(More)
Plant organ phenotyping by noninvasive video imaging techniques provides a powerful tool to assess physiological traits, circadian and diurnal rhythms, and biomass production. In particular, growth of individual plant organs is known to exhibit a high plasticity and occurs as a result of the interaction between various endogenous and environmental(More)