Table 2.
Definition of terms and formulae for calculation of JIP-test parameters from chlorophyll a fluorescence (ChlF) transient OJIP kinetics curves.
| Fluorescence Parameter | Description |
|---|---|
| Measured parameters and basic JIP-test parameters derived from ChlF transient OJIP kinetics curves | |
| F0 = F20 μs | Minimum fluorescence, when all PSII reaction centers (RCs) are open |
| Fk = F300 μs | Fluorescence intensity at 300 μs |
| Fj = F2 ms | Fluorescence intensity at the J-step (2 ms) |
| Fi = F30 ms | Fluorescence intensity at the J-step (30 ms) |
| Fm = FP | Maximum fluorescence, when all PSII RCs are closed |
| Vi = (F30 ms − F0)/(Fm − F0) | Relative variable fluorescence at the I-step (30 ms) |
| Vj = (F2 ms − F0)/(Fm − F0) | Relative variable fluorescence at the J-step (2 ms) |
| Wk = (F300 μs − F0)/(Fj − F0) | Ratio of variable fluorescence Fk to the amplitude Fj − F0 |
| M0 = 4 (F300 μs − F0)/(Fm − F0) | Approximated initial slop (in ms−1) of the fluorescence transient V = f(t) |
| Biophysical parameters derived from the fluorescence parameters | |
| Specific energy fluxes expressed per active PSII reaction center (RC) | |
| ABS/RC = M0 (1/Vj) (1/φPo) | Absorption flux (of antenna chlorophylls) per RC (also a measure of PSII apparent antenna size) |
| TR0/RC = M0 (1/Vj) | Trapping energy flux leading to QA reduction per RC (at t = 0) |
| ET0/RC = M0 (1/Vj) ψEo | Electron transport flux (further than QA−) per RC (at t = 0) |
| RE0/RC = M0 (1/Vj) (1 − Vi) | Quantum yield of electron transport from QA- to the PSI end electron acceptors, per RC |
| DI0/RC = (ABS/RC) − (TR0/RC) | Dissipated energy flux per RC (at t = 0) |
| RC/CS0 = φPo (Vj/M0) (ABS/CS0) ≈ φPo (Vj/M0) F0 | Density of active PSII RCs (QA− reducing PSII RCs) per illuminated cross section (CS) (at t = 0) |
| Quantum yields and efficiencies | |
| φPo = TR0/RC = [1 − (F0/Fm)] = Fv/Fm | Maximum quantum yield of primary PSII photochemistry (at t = 0) |
| ψo = ET0/TR0 = 1 − Vj | Probability (at t = 0) that a trapped exciton moves an electron into the electron transport chain beyond QA− |
| φEo = ET0/ABS = [1 − (F0/Fm)] ψo | Quantum yield for electron transport from QA− to plastoquinone (at t = 0) |
| φDo = F0/Fm = 1 − φPo | Quantum yield (at t = 0) of energy dissipation |
| δRo = RE0/ET0 = (1 − Vi)/(1 − Vj) | Efficiency/probability with which an electron from the intersystem electron carriers is transferred to the reduce end electron acceptors at the PSI acceptor side (RE) |
| φRo = REo/ABS = [1 − (F0/Fm)] (1 − Vi) | Quantum yield for reduction of end electron acceptors at the PSI acceptor side (RE) |
| Performance indexes | |
| PIABS = [γRC/(1 − γRC)] [φPo/(1 − φPo)] [ψo/(1 − ψo)] = (RC/ABS) [φPo/(1 − φPo)] [ψo/(1 − ψo)] | Performance index (potential) for energy conservation from photons absorbed by PSII to the reduction of intersystem electron acceptors |
| PItotal = PIABS [δRo/(1 − δRo)] | Performance index (potential) for energy conservation from photons absorbed by PSII to the reduction of PSI end acceptors |