What is OJIP?
OJIP or OJIDP is a dark adapted chlorophyll fluorescence technique that is used for plant stress measurement. It has been found that by using a high time resolution scale, the rise to maximum fluorescence from minimum fluorescence has intermediate peaks and dips, designated by the OJID and P nomenclature.
What is OJIP curve?
The OJIP phase of the Chl a fluorescence induction curve is referred. to as “fast transient” lasting for less than a second; it is obtained after a dark-adapted sample is exposed to saturating. light. In the OJIP curve, “O” stands for “origin” (minimal fluorescence), “P” for “peak” (maximum fluorescence), and J.
What is JIP test?
The JIP test refers to a translation of the original data into the following biophysical parameters, all referring to time zero (onset of fluorescence induction), that quantify the PSII behaviour: (1) the specific energy fluxes (per reaction centre) for absorption (ABS/RC), trapping (TR0/RC), dissipation (DI0/RC) and …
What is photochemical quenching in plants?
Photochemical quenching of EEE is the collective term for processes that increase the consumption of photosynthetic electrons by the deployment of additional metabolic sinks. These include the reduction of O2 at PSII or PSI (the Mehler reaction) and increased rates of photorespiratory metabolism [1].
What is FV fluorescence?
Chlorophyll fluorescence parameter Fv/Fm, which is the ratio of variable to maximum fluorescence after dark-adaptation, represents maximum quantum yield of PSII. The parameter has begun to be used for detecting stress in plants.
What causes fluorescence quenching?
Collisional quenching occurs when the excited fluorophore experiences contact with an atom or molecule that can facilitate non-radiative transitions to the ground state. Excited-state molecule collides with quencher molecule and returns to ground state non-radiatively.
What is Photoensitization photochemistry?
photosensitization, the process of initiating a reaction through the use of a substance capable of absorbing light and transferring the energy to the desired reactants.
What is meant by quantum yield?
Quantum yield (Φ) is defined as the ratio of the number of photons emitted to the number of photons absorbed. Notably, quantum yield is independent of instrument settings and describes how efficiently a fluorophore converts the excitation light into fluorescence.
What is FV FM in plants?
How does a fluorescence quencher work?
Fluorescence quenching is a physicochemical process that lowers the intensity of emitted light from fluorescent molecules. When a molecule absorbs light, electrons in its constituent atoms become excited and are promoted to a higher energy level.
How many types of quenching are there?
Three types of quenching can be experimentally distinguished: a quenching QF which is suppressed by a short saturating flash, a quenching QS destroyed under continuous illumination by a low efficiency process, and a quenching QR which cannot be destroyed at low temperature, but is removed by preillumination before …
What is photosensitized reaction and photosensitizer?
A reaction is considered photosensitized when an excited molecule (the donor or photosensitizer) induces photochemical reactions in molecules (the acceptor or quencher) that are not photochemically reactive by themselves, i.e., do not absorb light in the considered wavelength range.