Taras Pasternak

Taras Pasternak
University of Freiburg | Albert-Ludwigs-Universität Freiburg · Institute of Biology II

PhD

About

99
Publications
218,999
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4,624
Citations
Introduction
Working on plant biotechnology. Main interests are: role of stress and hormones interaction in plant development; mechanism of plant growth regulation in tissue culture in vitro; mechanism of cell de-differentiation on example on protoplast culture. View publications on the following link: http://scholar.google.de/citations?user=kWbssy8AAAAJ&hl=de&oi=ao
Additional affiliations
March 1998 - December 2002
HUN-REN Szegedi Biológiai Kutatóközpont
Position
  • PostDoc Position
January 1988 - December 2013
National Academy of Sciences of Ukraine
Position
  • PostDoc Position
December 2002 - March 2003
University of Antwerp
Position
  • PostDoc Position

Publications

Publications (99)
Article
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Haworthia truncata, a species native to South Africa, is characterized by its limited growth and scarcity, contributing to high production costs. Countries like China and Turkey are known for exporting Haworthia globally. Tissue culture offers an efficient method for mass-producing unique and beautiful species such as H. truncata. This study tested...
Article
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Key message We used marker-free technologies to study chromatin at cellular resolution. Our results show asymmetric chromatin distribution, explore chromatin dynamics during mitosis, and reveal structural differences between trichoblast and atrichoblast cell. Abstract The shapes, sizes, and structural organizations of plant nuclei vary considerabl...
Article
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Precise knowledge of all aspects controlling plant tissue culture and in vitro plant regeneration is crucial for plant biotechnologists and their correlated industry, as there is increasing demand for this scientific knowledge, resulting in more productive and resilient plants in the field. However, the development and application of cell and tissu...
Article
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Main conclusion Root development is regulated by sucrose and light during early seedling establishment through changes in the auxin response and chromatin topology. Abstract Light is a key environmental signal that regulates plant growth and development. The impact of light on development is primarily analyzed in the above-ground tissues, but litt...
Article
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Cultivated tomato (Solanum lycopersicum L.) is one of the most important horticultural crops in the world. The optimization of culture media for callus formation and tissue regeneration of different tomato genotypes presents numerous biotechnological applications. In this work, we have analyzed the effect of different concentrations of zeatin and i...
Article
Arabidopsis thaliana research relies heavily on the use of in vitro culture media for phenotypic characterization of seedling responses to intrinsic and extrinsic signals. For this, the most favorable growth conditions must be established and used as a reference, especially in those studies aimed at characterizing responses to abiotic and biotic st...
Article
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An environmentally responsive root system is crucial for plant growth and crop yield, especially in suboptimal soil conditions. This responsiveness enables the plant to exploit regions of high nutrient density while simultaneously minimizing abiotic stress. Despite the vital importance of root systems in regulating plant growth, significant gaps of...
Article
Reactive oxygen species (ROS) play a dual role in plant biology, acting as important signal transduction molecules and as toxic byproducts of aerobic metabolism that accumulate in cells upon exposure to different stressors and lead to cell death. In plants, root architecture is regulated by the distribution and intercellular flow of the phytohormon...
Article
Removal of the root system induces the formation of new roots from the remaining shoot. This process is primarily controlled by the phytohormone auxin, which interacts with other signals in a yet unresolved manner. Here, we study the classical tomato mutation rosette (ro), which lacks shoot-borne roots. ro plants were severely inhibited in forming...
Preprint
Full-text available
Removal of the root system induces the formation of new roots from the remaining shoot. This process is primarily controlled by the phytohormone auxin which interacts with other signals in a yet unresolved manner. Here, we study the classical tomato mutation rosette (ro) which lacks shoot-borne roots. ro plants were severely inhibited in the format...
Article
Root system architecture ultimately depends on precise signaling between different cells and tissues in the root apical meristem (RAM), and through its integration with environmental cues. This study describes a simple pipeline to simultaneously determine cellular parameters, nuclei geometry and cell cycle kinetics in the RAM. The method uses marke...
Article
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C4 photosynthesis increases the efficiency of carbon fixation by spatially separating high concentrations of molecular oxygen from rubisco. The specialized leaf anatomy required for this separation evolved independently many times. The morphology of C4 root systems is also distinctive and adapted to support high rates of photosynthesis; however, li...
Article
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When dealing with plant roots, a multiscale description of the functional root structure is needed. Since the beginning of 21st century, new devices such as laser confocal microscopes have been accessible for coarse root structure measurements, including three-dimensional (3D) reconstruction. Most researchers are familiar with using simple 2D geome...
Preprint
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When dealing with plant roots, a multi-scale description of the functional root structure is needed. Since the beginning of XXI century, new devices like laser confocal microscopes have been accessible for coarse root structure measurements, including 3D reconstruction. Most re-searchers are familiar with using simple 2D geometry visualization that...
Preprint
C4 photosynthesis increases the efficiency of carbon fixation by spatially separating high concentrations of molecular oxygen from rubisco. The specialized leaf anatomy required for this separation evolved independently many times. C4 root systems are highly branched, an adaptation thought to support high rates of photosynthesis; however, little is...
Article
Full-text available
Procedures for the direct regeneration of entire plants from a shoot and root protoplasts of Arabidopsis thaliana have been optimized. The culture media for protoplast donor-plant cultivation and protoplast culture have been adjusted for optimal plant growth, plating efficiency, and promotion of shoot regeneration. Protocols have been established f...
Preprint
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Root development is a complex spatial-temporal process that originates in the root apical meristem (RAM). To keep the organ’s shape in harmony, the different cell files’ growth must be coordinated. Thereby, diverging kinetics of cell growth in these files may be obtained not only by differential cell growth but also by local differences in cell pro...
Preprint
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DRPPP (Deep-Resolution Plant Phenotyping Platform) is a combination of protocols for plant tissue preparation, labeling, scanning, and open-source software to visualize and analyze 4D biological datasets. Here we describe a step-by-step procedure, including sample preparation and data analysis.
Article
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Root development is regulated by the tripeptide glutathione (GSH), a strong non-enzymatic antioxidant found in plants but with a poorly understood function in roots. Here, Arabidopsis mutants deficient in GSH biosynthesis (cad2, rax1, and rml1) and plants treated with the GSH biosynthesis inhibitor buthionine sulfoximine (BSO) showed root growth in...
Article
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The transport of auxin controls the rate, direction and localization of plant growth and development. The course of auxin transport is defined by the polar subcellular localization of the PIN proteins, a family of auxin efflux transporters. However, little is known about the composition and regulation of the PIN protein complex. Here, using blue‐na...
Article
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Root stem cell niche functioning requires the formation and maintenance of the specific “auxin-rich domain” governed by directional auxin transport and local auxin production. Auxin maximum co-localizes with the WOX5 expression domain in the quiescent center that separates mitotically active proximal and distal root meristems. Here we unravel the i...
Preprint
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Background: Arabidopsis research relies extensively on the use of in vitro growth for phenotypic analysis of the seedlings and characterization of plant responses to intrinsic and extrinsic cues. For this purpose, stress-free optimal growth conditions should be set up and used as a reference especially in studies aimed at characterizing the plant r...
Preprint
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The physiological status of differentiated somatic plant cells and kinetics of re-entering in cell cycle were investigated in the case of Medicago sativa leaf protoplasts after the application of oxidative stress-inducing agents. Excess copper (30 mkM) and alloxan (0.5 mM) accelerated cell cycle re-entry at an exogenous auxin concentration that alo...
Article
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Plants are sessile organisms that have a remarkable developmental plasticity, which ensures their optimal adaptation to environmental stresses. Plant cell totipotency is an extreme example of such plasticity, whereby somatic cells have the potential to form plants via direct shoot organogenesis or somatic embryogenesis in response to various exogen...
Article
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The key result of the work is the selection of factors for the cultivation of protoplasts of higher plants in vitro, which allowed induction of asymmetrical cell division during the first cell cycle phase. Gibberellin has been proved to be one of the main cofactors of asymmetric division of plant cells. The objects of research were plants of the fo...
Chapter
The protocol allows to define and characterize mitosis distribution patterns in the plant root meristem. The method does not require genetic markers, which makes it applicable to plants of different non-transgenic genotypes, including ecotypes, mutants, and non-model plant species. Computer analysis of the mitosis distribution in three dimensions w...
Article
The phytohormone salicylic acid (SA) is well known for its induction of pathogenesis-related (PR) proteins and systemic acquired resistance (SAR); SA also has specific effects on plant growth and development. Here we analyzed the effect of SA on Arabidopsis thaliana root development. We show that exogenous SA treatment at low (below 50 μM) and high...
Preprint
Full-text available
Large-scale methods and robust algorithms are needed for a quantitative analysis of cells status/geometry in situ. It allows the understanding the cellular mechanisms that direct organ growth in response to internal and environmental cues. Using advanced whole-stack imaging in combination with pattern analysis, we have developed a new approach to i...
Article
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The ancient morphoregulatory hormone auxin dynamically realigns dedicated cellular processes that shape plant growth under prevailing environmental conditions. However, the nature of the stress-responsive signal altering auxin homeostasis remains elusive. Here we establish that the evolutionarily conserved plastidial retrograde signaling metabolite...
Chapter
In plants as well as other organisms, protein localization alone is insufficient to provide a mechanistic link between stimulus and process regulation. This is because protein–protein interactions are central to the regulation of biological processes. However, they remain very difficult to detect in situ, with the choice of tools for the detection...
Article
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The Calcium-Dependent Protein Kinase (CDPK)-Related Kinase family (CRKs) consists of eight members in Arabidopsis. Recently, AtCRK5 was shown to play a direct role in the regulation of root gravitropic response involving polar auxin transport (PAT). However, limited information is available about the function of the other AtCRK genes. Here, we repo...
Article
To date CYCB1;1 marker and cortex cell lengths are conventionally used to determine the proliferation activity of the Arabidopsis root meristem. By creating a 3D map of mitosis distribution we showed that these markers overlooked that stele and endodermis save their potency to divide longer than cortex and epidermis. Cessation of cell divisions is...
Article
Using the intrinsic Root Coordinate System (iRoCS) Toolbox, a digital atlas at cellular resolution has been constructed for Nicotiana tabacum roots. Mitotic cells and cells labeled for DNA replication with 5-ethynyl-2’-deoxyuridine (EdU) were mapped. The results demonstrate that iRoCS analysis can be applied to thicker roots than those of Arabidops...
Article
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The WUSCHEL-RELATED HOMEOBOX 5 (WOX5) gene encodes the transcription factor, which is one of the key regulators maintaining the structure and functioning of the stem cell niche in plant root tips. WOX5 is expressed in the quiescent center of the root apical meristem, preventing the differentiation of the columella initials and, together with SCR, S...
Article
Full-text available
WUSCHEL RELATED HOMEOBOX 5 (WOX5) gene encodes the transcription factor, which is one of the key regulators, maintaining structure and functioning of the stem cell niche in plant root tips. Protein WOX5 is expressed in the quiescent center of the root apical meristem, preventing differentiation of columella initials and altogether with SCR, SHR, PL...
Article
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Ground-based simulators of microgravity such as fast rotating 2-D clinostats are valuable tools to study gravity related processes. We describe here a versatile g-value-adjustable 2-D clinostat that is suitable for plant analysis. To avoid seedling adaptation to 1 g after clinorotation, we designed chambers that allow rapid fixation. A detailed pro...
Article
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Background Theauxin efflux carrier PIN1 is a key mediator of polar auxin transport in developing plant tissues. This is why factors that are supposed to be involved in auxin distribution are frequently tested in the regulation of PIN1 expression. As a result, diverse aspects of PIN1 expression are dispersed across dozens of papers entirely devoted...
Article
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Rapid advances in microscopy have boosted research on cell biology. However sample preparation enabling excellent reproducible tissue preservation and cell labeling for in depth microscopic analysis of inner cell layers, tissues and organs still represents a major challenge for immunolocalization studies. Here we describe a protocol for whole-mount...
Article
Plant hormone auxin is the key factor in plant morphogenesis. Being unevenly distributed in plant tissues, it forms gradients and concentration maxima, according to which cells grow, divide, and differentiate. The family of PIN�FORMED (PIN) proteins representing transmembrane auxin transporters plays the key role in the formation of auxin gradients...
Article
To achieve a detailed understanding of processes in biological systems, cellular features must be quantified in the three-dimensional (3D) context of cells and organs. We introduce the intrinsic Root Coordinate System (iRoCS) as a reference model for the root apical meristem (RAM) of plants. iRoCS enables direct and quantitative comparison between...
Article
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Glutathione is involved in thiol redox signaling and acts as a major redox buffer against reactive oxygen species, helping to maintain a reducing environment in vivo. Glutathione reductase (GR) catalyzes the reduction of glutathione disulfide (GSSG) into reduced glutathione (GSH). The Arabidopsis thaliana genome encodes two GRs: GR1 and GR2. Wherea...
Article
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Background and AimsThe Mob1 family includes a group of kinase regulators conserved throughout eukaryotes. In multicellular organisms, Mob1 is involved in cell proliferation and apoptosis, thus controlling appropriate cell number and organ size. These functions are also of great importance for plants, which employ co-ordinated growth processes to ex...
Article
Glutathione (GSH) is an important scavenger of Reactive Oxygen Species (ROS), precursor of metal chelating phytochelatins, xenobiotic defence compound and regulator of cell proliferation. Homoglutathione (hGSH) is a GSH homologue that is present in several taxa in the family of Fabaceae. It is thought that hGSH performs many of the stress-defence r...
Article
Rho GTPase modifying bacterial protein toxins are useful for analysis of Rho signalling in animal cells, but these toxins cannot be taken up by plant cells. We demonstrate in vitro deamidation of Arabidopsis Rop4 by Escherichia coli Cytotoxic Necrotizing Factor 1 (CNF1) and glucosylation by Clostridium difficile toxin B. Expression of the catalytic...
Conference Paper
A role for the antioxidant glutathione in modulation of plant development and auxin transport has been proposed. In a number of Fabaceae, two types of thiols are present, glutathione and homoglutathione. This study investigates the role of glutathione and homoglutathione in cell cycle control in Medicago sativa, and especially during the transition...
Conference Paper
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We present a variational approach to simultaneously trace the axis and determine the thickness of 3-D (or 2-D) tubular structures defined by sparsely and unevenly sampled noisy surface points. Many existing approaches try to solve the axis-tracing and the precise fitting in two subsequent steps. In contrast to this our model is initialized with a s...
Article
A Nicotiana tabacum L. SR-1 leaf protoplast system was used to study the effects of dehydroascorbate and glutathione on cellular development. We found that dehydroascorbate is readily taken up by protoplasts and internally reduced to ascorbate. Concomitantly, cell division was inhibited and cell expansion stimulated. In this respect, dehydroascorba...
Article
Exposure of plants to mild chronic stress can cause induction of specific, stress-induced morphogenic responses (SIMRs). These responses are characterized by a blockage of cell division in the main meristematic tissues, an inhibition of elongation and a redirected outgrowth of lateral organs. Key elements in the ontogenesis of this phenotype appear...
Article
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Reactive oxygen species (ROS) are involved in various cellular processes in plants. Among those, resistance to abiotic stress, defence mechanisms and cell expansion have been intensively studied during the last years. We recently demonstrated that ROS, in concert with auxin, have a role in cell cycle activation of differentiated leaf cells.1 In thi...
Article
Plants exposed to sub-lethal abiotic stress conditions exhibit a broad range of morphogenic responses. Despite the diversity of phenotypes, a generic 'stress-induced morphogenic response' can be recognized that appears to be carefully orchestrated and comprises three components: (a) inhibition of cell elongation, (b) localized stimulation of cell d...
Article
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The activation of cell division and oxidative stress responses has been investigated in the case of leaf protoplast-derived cells. Initiation of protoplast culture was found to be associated with oxidative stress as indicated by the rate of H2O2 release into the medium and/or by catalase and ascorbate peroxidase activities. Both cell division frequ...
Article
Alfalfa leaf protoplast-derived cells can develop into somatic embryos depending on the concentration of 2,4-dichlorophenoxyacetic acid (2,4-D) in the initial culture medium. In order to reveal gene expression changes during the establishment of embryogenic competence, we compared the cell types developed in the presence of 1 and 10 microM 2,4-D, r...
Conference Paper
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Since biology and medicine apply increasingly fast volumet- ric imaging techniques and aim at extracting quantitative data from these images, the need for efficient image analysis techniques like detec- tion and classification of 3D structures is obvious. A common approach is to extract local features, e.g. group integration has been used to gain i...
Article
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It is now well established that nitric oxide (NO) serves as a signaling molecule in plant cells. In this paper experimental data are presented which indicate that NO can stimulate the activation of cell division and embryogenic cell formation in leaf protoplast-derived cells of alfalfa in the presence of auxin. It was found that various NO-releasin...
Article
Plant stress responses are a key factor in steering the development of cells, tissues, and organs. However, the stress-induced signal transduction cascades that control localized growth and cell size/differentiation are not well understood. It is reported here that oxidative stress, exerted by paraquat or alloxan, induced localized cell proliferati...
Article
Abiotic stress responses include changes in physiological and biochemical processes as well as morphological and developmental patterns. It has remained an enigma which mechanisms are responsible for stress-induced morphogenesis. In this paper we demonstrate that stress induced phenotypes comprise a re-orientation rather than a cessation of growth....
Article
Full-text available
Antibody expression and immunomodulation are modern molecular techniques to produce pharmaceuticals and to interfere with cellular metabolism or pathogen infectivity in plants. Nonetheless, there is still no generally applicable strategy to express correctly folded active antibodies or antibody fragments in different cell compartments. To facilitat...
Article
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To investigate the possible role of the non-symbiotic plant hemoglobins (phytoglobins) in relation to nitric oxide (NO) functions and their presumable involvement in NO- or pathogenesis-induced necrosis, we have produced transgenic tobacco plants (HOT lines) overexpressing an alfalfa hemoglobin cDNA (Mhb1) under the control of CaMV35S promoter. Upo...