A5028336664- Plant tissue culture and regeneration
- Microtubule and mitosis dynamics
- Plant Molecular Biology Research
- Plant Reproductive Biology
- Plant nutrient uptake and metabolism
- Plant Genetic and Mutation Studies
- Photosynthetic Processes and Mechanisms
- Seed Germination and Physiology
- Plant Pathogens and Resistance
- Chromosomal and Genetic Variations
- Nuclear Structure and Function
- Polyamine Metabolism and Applications
- Genomics and Chromatin Dynamics
- Mycotoxins in Agriculture and Food
- Plant Pathogens and Fungal Diseases
- Transgenic Plants and Applications
- Plant-Microbe Interactions and Immunity
- Ubiquitin and proteasome pathways
- Glycosylation and Glycoproteins Research
- Cancer-related Molecular Pathways
- 14-3-3 protein interactions
- Weed Control and Herbicide Applications
- Legume Nitrogen Fixing Symbiosis
- Plant Disease Resistance and Genetics
- Essential Oils and Antimicrobial Activity
Czech Academy of Sciences, Institute of Microbiology
2009-2022
Czech Academy of Sciences
2001-2022
Czech Academy of Sciences, Institute of Experimental Botany
1992-2007
Pediatrics and Genetics
2002
Palacký University Olomouc
1998-2001
University of Saskatchewan
1994-1999
Czech Academy of Sciences, Institute of Molecular Genetics
1998
De Montfort University
1995-1997
Vienna Biocenter
1997
University of Vienna
1997
Flow cytometry was used to analyse the DNA content of nuclei isolated from intact plant tissues and callus cell suspension cultures invitro. Cell were either mechanically (chopping, syringing) or by a hypotonic lysis protoplasts. Although both methods gave similar results, slight shift lower ploidy levels observed after protoplast isolation calli. No differences if two compared using cultures. The results showed that flow is rapid method nuclear analysis in variousin vitro
Abstract The rapidly proliferating cells in plant meristems must be protected from genome damage. Here, we show that the regulatory role of Arabidopsis RETINOBLASTOMA RELATED ( RBR ) cell proliferation can separated a novel function safeguarding integrity. Upon DNA damage, and its binding partner E2 FA are recruited to heterochromatic γH2 AX ‐labelled damage foci an ATM ‐ ATR ‐dependent manner. These lesions more dispersedly occupied by conserved repair protein, At BRCA 1, which also...
In eukaryotes, mitogen-activated protein kinases (MAPKs) are part of signaling modules that transmit diverse stimuli, such as mitogens, developmental cues, or various stresses. Here, we report a novel alfalfa MAPK, Medicago MAP kinase 3 (MMK3). Using an MMK3-specific antibody, detected the MMK3 and its associated activity only in dividing cells. The could be found during all stages cell cycle, but was transient mitosis correlated with timing phragmoplast formation. Depolymerization...
In plants after the disassembly of mitotic spindle, a specific cytokinetic structure called phragmoplast is built, and cytokinesis, microtubules populate cell cortex in an organized orientation that determines elongation shape. Here, we show impaired cyclin B1 degradation, resulting from mutation within its destruction box, leads to isodiametric shape epidermal cells leaves, stems, roots retarded growth seedlings. Microtubules these misshaped are grossly disorganized, focused around nucleus,...
ABSTRACT Mitogen-activated protein (MAP) kinases have been demonstrated to a role in meiosis but their involvement mitotic events is less clear. Using peptide antibody raised against the tobacco MAP kinase p43Ntf6 and extracts from synchronized cell suspension cultures, we show that this activated specifically during mitosis. Entry into mitosis appears be necessary for activation of kinase, which occurs as post-translational event. The late anaphase/early telophase. p43Ntf6protein shows...
γ-Tubulin is assumed to participate in microtubule nucleation acentrosomal plant cells, but the underlying molecular mechanisms are still unknown. Here, we show that γ-tubulin present protein complexes of various sizes and different subcellular locations Arabidopsis fava bean. Immunoprecipitation experiments revealed an association with αβ-tubulin dimers. cosedimented microtubules polymerized vitro localized along their whole length. Large resistant salt treatment were found be associated a...
Abstract γ-Tubulin is required for microtubule (MT) nucleation at MT organizing centers such as centrosomes or spindle pole bodies, but little known about its noncentrosomal functions. We conditionally downregulated γ-tubulin by inducible expression of RNA interference (RNAi) constructs in Arabidopsis thaliana. Almost complete RNAi depletion led to the absence MTs and was lethal cotyledon stage. After induction expression, gradually depleted from both cytoplasmic microsomal fractions. In...
A-type cyclin-dependent kinases (CDKs), also known as cdc2, are central to the orderly progression of cell cycle. We made a functional Green Fluorescent Protein (GFP) fusion with CDK-A (Cdc2-GFP) and followed its subcellular localization during cycle in tobacco cells. During interphase, Cdc2-GFP protein was found both cytoplasm nucleus, where it highly resistant extraction. In premitotic cells, bright narrow equatorial band appeared on surface, resembling late preprophase band, which...
Mitotic progression is timely regulated by the accumulation and degradation of A- B-type cyclins. In plants, there are three classes A-, two cyclins, but their specific roles not known. We have generated transgenic tobacco plants in which ectopic expression a plant cyclin B2 gene under control tetracycline-inducible promoter. show that induction cultured cells during G2 phase accelerates entry into mitosis allows to override replication checkpoint induced hydroxyurea simultaneous presence...
• The conserved family of Aurora kinases has multiple functions during mitosis. roles plant have been characterized using inhibitor treatments. We down-regulated in Arabidopsis thaliana RNA interference (RNAi). carried out a detailed phenotypic analysis RNAi plants, biochemical and microscopic studies AtAurora1 kinase together with AtTPX2 (targeting protein for Xklp2) γ-tubulin. Cell division defects were observed plants reduced expression kinases. Furthermore, the maintenance primary...
Summary Many events during cell division are triggered by an evolutionary conserved regulator, the cyclin‐dependent kinase (Cdk). Here we used two novel drugs, purine analogues bohemine and roscovitine, to study role of Cdks in cycle progression microtubule organisation Vicia faba root tip cells. Both drugs inhibited activity immunopurified alfalfa Cdc2‐kinase. The transcript levels A‐ B‐type cyclin, as well cdc2 genes, declined treated tips, while mRNA level a D‐type cyclin gene was not...
Neither the molecular mechanism by which plant microtubules nucleate in cytoplasm nor organization of mitotic spindles, lack centrosomes, is well understood. Here, using immunolocalization and cell fractionation techniques, we provide evidence that γ-tubulin, a universal component microtubule organizing centers, present both nucleus cells. The amount γ-tubulin nuclei increased during G2 phase, when cells are synchronized or sorted for particular phases cycle. γ-Tubulin appeared on...
Abstract To study a cyclin-dependent kinase (CDK) from alfalfa (Medicago sativa L.), an antibody was raised against the C-terminal 16 amino acids of protein cdc2aMs. The cdc2Ms immunopurified with this and its histone activity measured. is activated at G1/S transition when phosphate-starved cells G0 phase re-enter cell cycle remain active as transit S, G2, M phases, indicating that same CDK regulates all these phases in alfalfa. In contrast, purified by binding to p13suc1, it only G2 phases....
TPX2 performs multiple roles in microtubule organization. Previously, it was shown that plant AtTPX2 binds AtAurora1 kinase and colocalizes with microtubules a cell cycle-specific manner. To elucidate the function of further, this work analysed Arabidopsis cells overexpressing AtTPX2-GFP. Distinct arrays bundled microtubules, decorated AtTPX2-GFP, were formed vicinity nuclear envelope nuclei cells. The microtubular showed reduced sensitivity to anti-microtubular drugs. TPX2-mediated...
Abstract Background RanBPM (Ran-binding protein in the microtubule-organizing centre) was originally reported as a centrosome-associated human cells. However, containing highly conserved SPRY, LisH, CTLH and CRA domains is currently considered scaffolding with multiple cellular functions. A plant homologue of has not yet been characterized. Results Based on sequence similarity, we identified Arabidopsis thaliana. AtRanBPM domains. Cell fractionation showed that endogenous or expressed...
Summary Monoclonal antibodies raised against a phylogenetically conserved peptide from the C‐terminal domain of γ‐tubulin molecule were used for immunofluorescence detection in acentriolar mitotic spindles plant cells. The stained kinetochore fibres along their whole length, including close vicinity kinetochores. After microtubule disassembly by antimicrotubular drugs amiprophos‐methyl, oryzalin and colchicine, was found on remnants attached to chromosomes. In cells recovering...
Stress-activated plant mitogen-activated protein (MAP) kinase pathways play roles in growth adaptation to the environment by modulating cell division through cytoskeletal regulation, but mechanisms are poorly understood. We performed interaction and phosphorylation experiments with proteins, mass spectrometric identification of MPK6 complexes immunofluorescence analyses microtubular cytoskeleton mitotic cells using wild-type, mpk6-2 mutant plants overexpressing MAP kinase-inactivating...
Summary Nitrilases are highly conserved proteins with catabolic activity but much less understood functions in cell division and apoptosis. To elucidate the biological of A rabidopsis NITRILASE 1, we characterized its molecular forms, cellular localization involvement proliferation plant development. We performed biochemical mass spectrometry analyses 1 complexes, electron microscopy nitrilase polymers, imaging developmental distribution, silencing overexpression nitrilases to study their...
γ-Tubulin is associated with microtubule nucleation, but evidence accumulating in eukaryotes that it also functions nuclear processes and cell division control independently of its canonical role. We found Arabidopsis thaliana, γ-tubulin interacts specifically E2FA, E2FB, E2FC transcription factors both vitro vivo. The interaction the E2Fs not reduced presence their dimerization partners (DPs) and, agreement, we does require domain. associates promoters E2F-regulated cycle genes an...
The effect of inhibition phenylpropanoid biosynthesis on the growth Medicago sativa L. suspension culture was studied. 2‐Aminoindan‐2‐phosphonic acid (AIP), a potent inhibitor phenylalanine ammonia‐lyase (PAL; EC 4.3.1.5), caused marked reduction in amount hydroxycinnamic derivatives few hours after cell inoculation into AIP medium. treatment alfalfa with this increased extractable PAL activity and elevated ethylene production during cycle. addition (10 μ M ) stimulated division cycle,...