Glossar Plant Cell Biology
What for a glossary?
Science is based on clear thoughts. Clear thoughts need clear terminology. In each profession, there exists a vocabulary, one needs to know to efficiently communicate with others.
| ENG | D | Bedeutung |
| acquisition | Aufnahme (von Bildern) | collection of microscopical images |
| active transport | aktiver Transport | transport across a membrane that is driven by external energy (against chemical gradients) |
| anisotropic | anisotrop | literally "not equal in all directions", i.e. there is a directionality, e.g. in the cell wall expansibility |
| apotomy | Apotomie | simple form of structured illumination using an optical grid which is moved over the specimen to separate focal and non-focal pixels |
| aptamers | Aptamere | artificial RNA molecules with defined threedimensional structures used for engineering target molecules in a cell |
| aquaporins | Aquaporine | membrane channels that transport water or small molecules and increase conductance in case of limitations |
| artifact | Artefakt (arte factum) | false experimental data produced by problems of methodology or equipment |
| auxin canalisation | Auxinkanalisierung | the formation of a pattern of auxin flow by global influx and polarised efflux, guides the formation of vasculature |
| averaging | Mittelung | procedure in confocal microscopy, where subsequent images of a stack are overlaid to improve signal-noise ratio |
| beam splitter | Farbteiler | interference filter in epifluorescence microscopy that reflects the excitation light, but transmits the fluorescent light |
| biolistics | Biolistik | from Bio-Ballistics, shooting foreign DNA into cells (can be transient or stable, depending on the vector)
|
| birefringency | Doppelbrechung | different diffraction of polarised light depending on direction, diagnostic property for elongated, polar macromolecules (cellulose) |
| Bimodal Fluorescence Complementation (BiFC) | Fluoreszenz-Komplementierung |
Fluorescence produced by two interaction partners fused to the two halves of a split YFP |
| bioluminescence | Biolumineszenz | Conversion of chemical energy into light (does not require excitation!), e.g. Aequorin |
| birefringent | doppelbrechend | different refraction depending on the direction of polarised light, caused by elongated, polar molecules |
| BODIPY | BODIPY | Boron-DiPyrrromethene based fluorochromes with superior optical properties |
| Broglie Law | Broglie Gesetz | describes the relationship between wavelength and frequency: their product equals c (velocity of light) |
| caged compounds | photoaktivierbare Komponenten | bioactive molecules that are inactivated in a chelated "cage" that can be released by a light beam |
| cameleon | Chamäleon | artificial fluorescent Protein consisting of CFP and YFP connected by a calmodulin linker, used as calcium sensor via FRET |
| Cavallieri Method | Cavallieri-Methode | Approach of stereology, where the volume of an object is estimated from the relative area in several sections of a z-stack |
| Caveat |
lat. für "man passe auf" |
a point in science, where data are easily misinterpreted due to false concepts or experimental ambiguities |
| cell lineage | Zellabstammungslinie | predictable sequence of cell divisions, in some organism used to control cell differentiation |
| cell permeating peptides (CPP) | cell permeating peptides | Peptides that can cross the plasma membrane by unknown mechanisms (not by endocytotic uptake!) |
| chemical engineering | chemical engineering | direct manipulation of biological processes by chemical agents independent of manipulation of DNA |
| coassembly assay | Koassemblierungstest | method to purify MAPs by assembly from soluble tubulin |
| codon usage bias | Codonasymmetrie | Asymmetric occurrence of the different tRNAs conjugated to a given amino acid residue, organism-specific |
| constitutive promotor | konstitutiver Promotor | promotor that is always active, useful for GFP localisation |
| cosedimentation assay | Kosedimentierungstest | method to purify MAPs by binding to preassembled (taxol-stabilised) microtubules |
| coupling | Kopplung | connection between two oscillators, can be strict (physical) or weak (by resonance) |
| CRAP (colour recovery after photoactivation) | Farberholung nach Photoaktivierung | new approach for protein dynamics like FRAP, but using the colour change of photoconvertible fluorochromes instead |
| DAPI | DAPI | most important nuclear dye, excited in the near UV, emission in the blue |
| dichroitic mirror, beam splitter | dichroitischer Spiegel, Farbteiler | Filter that reflects or transmits light depending on wavelength |
| differentiation | Differenzierung | developmental differences between cell types in adaption to specific functions |
| diffraction | Brechung | Change in the direction of a light beam upon transition between different optical density (diffraction index) |
| diffraction limit | Auflösungsgrenze | The smallest distance that can be resolved by light microscopy. According to Abbé's Law this limit is defined as ratio of wavelength by numerical aperture. |
| DR5 | DR5 | Minimal auxin-responsive promotor made of a 5' mutation of auxin-response element D1-4 of the gene GH3 |
| dynein | Dynein | motor protein moving along microtubules towards the less dynamic minus-end |
| EB1 | EB1 | microtubule plus-end marker, stabilises protofilaments against disruption |
| emission | Emission | Generation of light by an excited fluorochrome by transition from the singulet back to the ground state |
| endokaryotic Hypothesis | Endokaryon-Hypothese | model that the nucleus formed by an endosymbiotic event from an Archaebacterial ancestor |
| enhancer trap | enhancer trap | minimal promotor driving a reporter inserted into plants to "trap" tissue-specific active enhancers |
| entity | Ganzheit | a unit that acts as a whole (individuum) |
| epifluorescence | Auflicht-Fluoreszenz | Microscopical set-up, where the excitation light is administered through the objective to the specimen |
| evanescent field | evaneszentes Feld | Generation of a weak wave-front during total reflection at the border between different diffraction indices |
| excitation | Anregung | Transition of a fluorescent molecule from the ground state into the singulet-state by absorption of a photon |
| FACS | Fluoreszenz-Zellsortierung | Separation of fluorescently labelled from unlabelled cells/structures in a liquid flow |
| false causality | falsche Kausalität | correlation of two events that are not causally linked (e.g. stork number and birth rate) |
| flow cytometry | Fluss-Cytometrie | FACS-based procedure to count cells/nuclei of different DNA-content |
| fluorochrome | Fluoreszenzfarbstoff | Molecule that is excited for fluorescence in the visible range |
| FRAP | Fluoreszenz-Regenerierung | Fluorescent Recovery After Photobleaching - approach to measure protein dynamics by bleaching a ROI |
| FRET | Förster-Resonanz | stands for fluorescence resonance energy transfer (irradition-free energy transfer between a pair of fluorochromes) |
| FtsZ | FtsZ | filamentous temperature sensitive Z - a cell division factor of bacteria, later found to be homologous to tubulin |
| germ line | Keimbahn | those cells in a multicellular organism that will generate the propagation cells (contrast: soma) |
| gigaseal | Gigaohm-Widerstand | in patch clamping electrically tight connection between membrane and pipette to ensure absence of leak current |
| Green Revolution Genes | Green Revolution Genes | genes with alleles that contributed to the 5-fold yield increase achieved during Green Revolution (1950-1980) |
| heterotcysts | Heterocysten | specialised cells in cyanobacteria that can fix nitrogen |
| histochemistry | Histochemie | classical staining methods to visualise specific molecules in microscopical specimens |
| intermediate filaments | Intermediärfilamente | filaments that are intermediate between actin and microtubules, absent in plants (even laminin maintaining the nucleus in animals) |
| Jablonski scheme | Jablonski Diagramm | graph of energy levels of fluorescent molecules |
| karyogenesis model | Karyogenese-Modell | model that the nucleus originated de-novo from endomembranes wrapped around the DNA (in contrast to endokaryon model) |
| katanin | Katanin | microtubule severing protein |
| kinesin | Kinesin | motor protein moving along microtubules, in most cases towards the dynamic plus-end |
| laser ablation | Laserablation | destruction of biological structures or cells by a two-photon laser configuration without damaging neighbourhood |
| laser capture microdissection | Laserbasierte Mikrosektion | excision of a region of interest by a laser and extraction by a low vacuum to collect specific tissues |
| light-sheet microscopy | Lichtblattmikroskopie | advanced form of confocal microscopy, where a narrow light sheet is generated by lateral irradiation, such that only the focal plane is excited |
| mechanosensitive channel | mechanosensitiver Kanal | ion channel that opens in response to mechanic strain |
| microfibril | Mikrofibrille | fiber composed of 36 cellulose chains that are drilled up, element of the plant-cell wall |
| microfilaments | Mikrofilamente | polymers composed of actin monomers (F-actin), nowadays people use "actin filaments" instead |
| microtubules | Mikrotubuli (Ez. -tubulus) | polymers composed of heterodimers of a- and b-tubulin |
| monorail model | Schienenmodell | model for cell-wall anisotropy by kinesin-driven movement of cellulase synthase along microtubules |
| moonlighting | Schwarzarbeit | second job (in the night), used for secondary functions of proteins (often preadaptations for functional change) |
| myosin | Myosin | motor protein moving along actin filaments |
| NLS | Kernsignatur | nuclear localisation sequence, peptide motif responsible for import of proteins into the nucleus |
| nsPEFs | ns-Pulsfelder | pulsed electrical fields of short duration (ns) and high voltage (1 kV/cm), induce apoptosis |
| numerical aperture | numerische Apertur | product of sin a (opening angle of objective) and diffraction index n (1 for air, 1.41 for glass) |
| on-cell configuration | Ganz-Zell-Aufbau | in patch clamp: configuration, where the patch pipette sits on an intact cell |
| optical tweezers | optische Pinzette | manipulation of small structures by a strong laser beam, based on gradients in diffractive index |
| overexpression artifact | Überexpressionsartefakt | effect on a phenotype caused by overexpression of a transgene |
| PALM microscopy | PALM Mikroskopie | stands for photoactivated laser microscopy, synonym for STORM |
| pattern formation | Musterbildung | development of a non-random arrangement of different cells |
| perception | Reizwahrnehmung | start point of signaling by recognition of a signal by a receptor |
| phalloidin | Phalloidin | secondary compound of the toadstool Amanites phalloides that stabilises F-actin and is used to stain actin filaments |
| photoactivable | lichtaktivierbar | Fluorochrome, where fluorescence properties can be switched by light different from fluorescence |
| phragmoplast | Phragmoplast | plant-specific microtubule array that organises the forming cell-plate in telophase |
| phyllotaxis | Phyllotaxis | the species-dependent patterning of leave positions, following the Fibonacci sequence |
| pinhole | Lochblende | Small hole in confocal laser microscopy filtering light depending on its geometrical relation with the focal plane |
| Planck's Law | Plancksches Gesetz | describes the relation between the energy of a photon and its wave number (frequency): E = h ν |
| polarisation microscopy | Polarisationsmikroskopie | variation of light microscopy using two crossed polarisation filters for visualisation of structural birefringency |
| polarity | Polarität | a gradient of activity in space, specifically for the cytoskeleton: the direction between (+)- and (-)-end |
| PPB | Präprophaseband | plant-specific microtubule array at the G2/M transition, predicting axis and symmetry of cell division |
| probe | Sonde |
Specific molecules that are used to investigate a specific biological process |
| protofilament | Protofilament | row of tubulin dimers, 13 protofilaments form the microtubule |
| protonema | Protonema (Vz. -nemata) | filamentous gametophyte of ferns, upon blue light irradiation transformed into bidimensional prothallium |
| ratio-imaging | Verhältnis-Abbildung | Approach in quantitative image analysis, where pixel intensities obtained at two emission wavelengths are divided to remove the influence of intensity changes not caused by the fluorochrome of interest |
| reaction-diffusion system | Reaktions-Diffusionssystem | processes that are autocatalytic (self-amplifying), but coupled by mutual inhibition, produce self-organisation that is independent of size. The driving model for biological morphogenesis |
| reporter | Reportergen | Gene that is easily detected and reports the activitiy of the promotor under whose control it was placed |
| ROI | Zielregion | Region of interest which is in the focus of investigation |
| scalar | skalar | independent of direction (not in a gradient) |
| second messenger | second messenger | signaling from receptors at membrane to nucleus by signaling molecules (kinase cascades, inositpathways, cAMP) |
| SEM | REM | scanning electron microscopy (Rasterelektronenmikroskopie) |
| SIM | strukturierte Beleuchtung | approach to use interference patterns for excitation that can be smaller than the diffraction limit. |
| STED | STED | stands for stimulated emission depletion, a specimen is excited by a laser and the excitation is quenched by a second laser. Due to interference of the laser waves, it is possible to generate an excitation spot that is smaller than the diffraction limit |
| SNAP tag | SNAP tag | coupling of a target molecule to non-peptidic ligands in vivo using a enzymatic tag targeted to nucleotids |
| soma | Soma | cells constituting the body of an organism, whereas the germ line (Keimbahn) is the cell line yielding the germ cells |
| Spinning disc microscopy | Drehscheiben-Mikroskopie | confocal technique, where a disc with numerous pinholes rotates to increase scanning speed |
| stem cells | Stammzelle | cell that divides asymmetrically giving rise to one daughter that maintains the stem cell quality: A gives A+B |
| Stokes-Shift | Stokes-Verschiebung | In fluorescence shift of the emitted light to lower energy (longer wavelength), caused by dissipation of heat during transition between different singulet states |
| STORM | STORM | stands for 3D stochastic optical reconstruction microscopy, approach to reconstruct the exact position beyond the diffraction limt by using temporal information of a photoactivable fluorochrome. |
| stromules | Stromuli | filamentous extensions of plastids (similar to bacterial sex pili), thought to form networks, disproven by mEOS-FP experiments |
| susception | Suszeption | transformation of a physical stimulus into a energy that can be used for perception |
| telome | Telom | modular unit of higher plants consisting of vasculature, ground tissue, and epidermis |
| TIRF | TIRF | stands for total-internal reflection microscopy using the fact that an evanescent field can penetrate only a very short distance into the sample such that only the uppermost 50-100 nm are excited. |
| totipotency | Omnipotenz | the ability of a cell to regenerate an entire organism (animals: germ cells, plants: all cells) |
| tubulin | Tubulin | building block of microtubules, heterodimer composed of a- and b-subunit |
| Turing systems | Turingsysteme | reaction diffusion systems that have been recognised by Alan Turing as core principle of biology |
| two-Photon Laser | Zweiphotonenlaser | two coupled lasers of low energy are focussed such that energy is added up in the focus site |
| vascular bundle | Leitbündel | transport tissue of land plants consisting of xylem and phloëm |
| visualise / visualize | markieren | to render a protein or structure visible, usually by specific labels |