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Start Over Creator Vredenberg, W. J.

1. Application of non-invasive spectroscopic and photoacoustic techniques in research on photosynthetic performance of intact leaves

Creator:
Vredenberg, W. J., Snel, J. F. H., Buurmeuer, W. F., and Boumans, H.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
The principles and application prospects of a set-up for simultaneous measurements of oxygen evolution and fluorescence in intact leaves on a fast (10 ms) time scale are descríbed. The oxygen evolution is measured with a photoacoustic technique. The method shows among other things (a) a direct deteimination of the intrinsic yield of 'open' reaction centres (RCs) of photosystem 2 (PS 2), and (b) ihe involvement of a 20-30 % firaction of PS 2 RCs with an apparent low oxygen yield in the light-adapted leaves. Double-flashPS 15 measurements in the light- and dark-adapted leaves have substantiated the absence of inactive RCs in leaves that were kept in the dark for more than 12 h.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2. On the quantitative relation between dark kinetics of NPQ-induced changes in variable fluorescence and the activation state of the CF0·CF1·ATPase in leaves

Creator:
Vredenberg, W. J.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
systémová analýza, fluorescence, kinetika, system analysis, kinetics, CF0·F1·ATPase, chlorophyll fluorescence kinetics, nonphotochemical quenching, Kautsky fluorescence induction curve, quenching mechanisms, 2, and 581
Language:
Multiple languages
Description:
The variable fluorescence at the maximum Fm of the fluorescence induction (Kautsky) curve is known to be substantially suppressed shortly after light adaption due to nonphotochemical qE quenching. The kinetic pattern of the dark decay at Fm consists of three components with rates ~20, ~1, and ~0.1 s-1, respectively. Light adaptation has no or little effect on these rate constants. It causes a decrease in the ratio between the amplitudes of the slow and fast one with negligible change in the small amplitude of the ultra-slow component. Results add to evidence for the hypothesis that the dark-reversible decrease in variable fluorescence accompanying light adaptation during the P-S phase of the fluorescence induction curve is due to an alteration in nonphotochemical qE quenching caused by changes in the trans-thylakoid proton motive force in response to changes in the proton conductance gH+ of the CF0-channel of the CF0·CF1·ATPase., W. J. Vredenberg., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public