Glossar Plant Cell Biology

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ENG D Bedeutung
Abbé's Law Abbé-Regel describes the relationship between resolution and wavelength: D = λ / N.A.
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

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
closed pattern formation geschlossene Musterbildung a pattern, where first the cells are produced and only then differentiate (typical for animal development)
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)
haplodiploidisation Haplodiploidisierung rendering a plant homozygous by producing an embryo from pollen, followed by induced diploidisation
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
native promoter nativer Promoter the promoter of the expressed gene itself (in contrast to a constitutive promoter)
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
optogenetics Optogenetik manipulation of cells or organisms by light using light-switchable transgenic constructs
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