Detection of rapid induction kinetics with a new type of high-frequency modulated chlorophyll fluorometer

  title={Detection of rapid induction kinetics with a new type of high-frequency modulated chlorophyll fluorometer},
  author={Ulrich Schreiber},
  journal={Photosynthesis Research},
A newly developed modulation fluorometer is described which operates with 1 μsec light pulses from a light-emitting diode (LED) at 100 KHz. Special amplification circuits assure a highly selective recording of pulse fluorescence signals against a vast background of non-modulated light. The system tolerates ratios of up to 1:107 between measuring light and actinic light. Thus it is possible to measure the “dark fluorescence yield” and record the kinetics of light-induced changes. A high time… 

Assessment of wavelength-dependent parameters of photosynthetic electron transport with a new type of multi-color PAM chlorophyll fluorometer

ETR qualifies for quantifying the absolute rate of electron transport in optically thin suspensions of unicellular algae and cyanobacteria as well as the applied methodology and some typical examples of its practical application with suspensions of Chlorella vulgaris and Synechocystis PCC 6803 are presented.

The polyphasic chlorophyll a fluorescence rise measured under high intensity of exciting light.

  • D. Lazár
  • Biology
    Functional plant biology : FPB
  • 2006
The K-step, usually detected after a high-temperature stress, and other steps appearing in the transient (the H and G steps) are discussed, and some applications of the transient are also mentioned.

Studies on the adaptation of intact leaves to changing light intensities by a kinetic analysis of chlorophyll fluorescence and oxygen evolution as measured by the photoacoustic signal

A detailed quantitative study of the kinetics of photochemical and non-photochemical quenching was achieved by a linear analysis of the yields of chlorophyll fluorescence and of oxygen evolution by their responses to sinusoidal changes of actinic light.

An improved method, using saturating light pulses, for the determination of photosystem I quantum yield via P700+-absorbance changes at 830 nm

An improved method is introduced for the determination of the quantum yield of photosystem I. The new method employs saturating light pulses with steep rise characteristics to distinguish, in a given

Control of Photosystem II in spinach leaves by continuous light and by light pulses given in the dark

It is suggested that qNs is the result of a so-called state transition, in which LHC II moves after its phosphorylation from fluorescent PS II to nonfluorescent PS I, capable of decreasing in darkened leaves the potential maximum quantum efficiency of electron flow through Photosystem II by about 20%.

Measurement of chlorophyll fluorescence within leaves using a modified PAM Fluorometer with a fiber-optic microprobe

The new system employs a miniature photomultiplier for detection of the pulse-modulated fluorescence signal received by the 20 μm fiber tip and qualifies for recordings of fluorescence induction kinetics (Kautsky effect), fluorescence quenching by the saturation pulse method and determination of quantum yield of energy conversion at Photosystem II at different sites within a leaf.

Demonstration of a highly-sensitive portable double-flash kinetic spectrophotometer for measurement of electron transfer reactions in intact plants

A highly sensitive, portable spectrophotometer for use in measuring flash-induced absorbance changes in intact leaves is demonstrated, following the kinetics of the electrochromic shift, the change in redox states of cytochrome f and the b cytochromes in an intact cucumber leaf, and in the same leaf after infiltration with DCMU.

Correlation between chlorophyll fluorescence and photoacoustic signal transients in spinach leaves

A good correlation was found between photoacoustically detected oxygen evolution at 35 Hz modulation frequency and electron flow calculated from the fluorescence quenching coefficients qP and qN.

New type of dual-channel PAM chlorophyll fluorometer for highly sensitive water toxicity biotests

A new type of dual-channel PAM chlorophyll fluorometer has been developed, which is specialised in the detection of extremely small differences in photosynthetic activity in algae or thylakoids suspensions, and provides an ultrasensitive biotest system for detection of toxic substances in water samples.

Analysis of initial chlorophyll fluorescence induction kinetics in chloroplasts in terms of rate constants of donor side quenching release and electron trapping in photosystem II

It is shown, in agreement with the theory, that the sigmoidicity of the fluorescence rise is variable with light intensity and mainly, if not exclusively, determined by the ratio between rate of light excitation and the rate constant of donor side quenching release.


In studies on microalgae and photosynthetic bacteria, pp. 353-372

  • 1963