ISSN:
1573-5079
Keywords:
fluorometer
;
fluorescence yield
;
Photosystem II
;
spinach
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Newly developed equipment is described that permits the monitoring of laser flash induced transients of the normalised chlorophyll-a fluorescence quantum yield in isolated PS II preparations and whole leaves with a high time resolution. The essential operational unit of the set-up is a rapidly gated photomultiplier. In this way, the fluorescence artefact, due to the high intensity excitation laser flash, is sufficiently suppressed and the dead time of the signal response is reduced to about 500 ns. It is shown that the fluorescence rise kinetics in the μs time-domain, after flash excitation is strongly dependent on the redox state of the primary electron donor of PS II (P680). At high excitation energies, the decay of carotenoid triplets, which are very efficient quenchers of chlorophyll singlet states, dominates the rise kinetics of the flash induced fluorescence yield in the μs time domain.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1005881810057
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